WELDWELL NEW ZEALAND proudly present their range of arc welding electrodes in this book. We have manufactured electrodes in New Zealand since 1967. There are constant changes in this field because technology never stands still and we have access to welding electrode research to back our activities in the market place. We provide technical people to service our clients throughout Australasia, in countries of the Pacific Basin and in South East Asia. Therefore if you require help or advice with your welding problems, please ask and we will gladly assist. Included in our factory facilities is our own laboratory for materials, quality control and equipment to enable quick evaluation of new developments. This enables us to provide you, the customer, with the top quality electrodes you need for each application. The Weldwell Electrode Factory operates to the Telarc accredited ISO 9001 Quality Assurance System.
CONTENTS INTRODUCTION
Selecting the right Electrode Classification Survey American Classification Australian Classification
Page
Page 2 2 3 5
ELECTRODES FOR WELDING STAINLESS STEELS
Introduction Electrode Recommendation Weldwell PH RS308LC Weldwell PH BM310 Weldwell PH RM316LC Weldwell PH RM318LC WIA Staincord 316L-16 Weldwell PH RS309LC Weldwell PHRS309MoLC Weldwell PH 22.9.3LR
57 58 58 59 59 60 60 61 61
ELECTRODES FOR WELDING PROBLEM STEELS
Introduction Weldwell Elite RSP Weldwell Elite Hi-Ten 8
62 63 64
SECTION ONE WELDING FUNDAMENTALS Definition of arc welding terms Arc Welding - The Process Welding Equipment The Welding Electrode The Welding Current Welding Positions and Weld Joints Welding Technique Defects due to faulty technique Distortion Metallurgical facts about iron and steel Mild Steel High Tensile and Alloy Steels Stainless Steel Manganese Steel Cast Irons Non Ferrous Metals Hardfacing Cutting with the electric arc
SECTION TWO TECHNIQUES FOR SELECTED APPLICATIONS SECTION THREE WELDWELL WELDING ELECTRODES
7 9 9 10 10 11 12 13 16 17 17 18 18 19 20 21 21 22
23
Introduction Weldwell PH 28 WIA Austarc 12P Weldwell PH 45E Weldwell PH 46 Weldwell PH 48A Weldwell PH 68 Weldwell PH 78 Weldwell PH C18 Weldwell PH 22 Weldwell PH 7024 Weldwell PH 31A Hobart Pipemaster 60 Hobart Pipemaster 70
28 29 30 31 32 33 34 35 36 37 38 39 40 41
Introduction Weldwell PH 27 Weldwell PH 27P WIA Austarc 16TC Weldwell PH 56S Weldwell PH 56R Weldwell PH 75 Weldwell PH 77 Weldwell PH C6H Weldwell KV3
42 43 44 45 46 47 48 49 50 51
ELECTRODES FOR WELDING HIGH TENSILE STEEL
Introduction Weldwell PH 118
52 53
ELECTRODES FOR WELDING CREEP RESISTANT STEELS
Introduction Weldwell KV3 Weldwell KV5
54 55 56
ELECTRODES FOR WELDING MILD STEEL
LOW HYDROGEN ELECTRODES FOR WELDING MILD AND MEDIUM TENSILE Low Temperature
ELECTRODES FOR GOUGING AND CUTTING
Introduction Austarc C&G
65 66
ELECTRODES FOR WELDING CAST IRON
Introduction Supercast Ni Supercast NiFe
67 68 68
ELECTRODES FOR HARDFACING
Introduction Weldwell PH MN Weldwell PH 250 Weldwell PH 400 Weldwell PH 600 Weldwell PH 700 Abrasocord 43 Vidalloy 11 Vidalloy 30
69 70 71 72 73 74 75 76 76
ELECTRODES FOR SPECIAL METALS
Introduction Bronze Arc Ally Arc
77 78 79
SECTION FOUR MISCELLANEOUS Relationship between stress and energy 80 Deposition rate conversion chart 80 Physical properties of metals and alloys 81 Conversion chart - inch/millimetre 81 Work, energy, foot pounds - force to joules 82 Steel testing by spark method 82 American Welding Society standard welding symbols 83 Mensuration 85 Comparative hardness scales 86 Arc welding lenses 86 Care and Storage of electrodes 87 Recommendations for storage and drying 88 Electrode Agency Approval Grades 89 Electrode Quantities per Packet 90 Weld Deposition and Costing Data 91 Weldwell Distributors 97 Weldwell Branches Inside Back Cover
1
SELECTING THE RIGHT ELECTRODE
INTRODUCTION
PICKING THE RIGHT ELECTRODE is a matter of analysing the conditions applying to a particular job and then determining the type and size of electrode best suited to those conditions. Such an analysis is if the operator makes a practice of always checking the following factors: (1) What is the base metal to be welded? (2) Dimensions of the section to be welded. (3) What type of current is available? (4) What welding position, or positions, will be used? (5) What sort of fit up does the work permit? (6) Must weld deposit possess any specific properties such as corrosion resistance, high tensile strength, ductility, etc? (7) Must weld meet requirements of any code, standard, specification or approval. After carefully checking the above factors the operator should have no difficulty in selecting a Weldwell electrode type which will provide the arc stability, smoothness of bead, easy slag removal, and minimum spatter which are so essential to fast, top quality arc welding.
CLASSIFICATION CROSS REFERENCE LIST
(Nearest Equivalents)
ELECTRODES FOR WELDING MILD STEEL Weldwell PH 28 Austarc 12P PH 31A Pipemaster 60 Pipemaster 70 PH 45E PH 46 PH 48A PH 68 PH 78 PH C18 PH 22 PH 7024
AWS A5.1:2004 E6013 E6013 E6011 E6010 E7010-01 (AWS A5.5) E6020 E6012 E6013 E6013 E6013 E7014 E7024 E7024
AS/NZS1553.1:1995 E4112-0 E4112-0 E4111-3 E4110-3 E4810-01 (AS/NZS 1553.2) E4120-0 E4113-0 E4112-0 E4112-A E4113-2 E4814-0 E4824-0 E4824-0
BSEN499:1995 E350R11 E350R11 E353C11 E383C21 E382MOC21 E35ZRA13 E350R12 E350R11 E350R11 E350R12 E380RR31 E380RR53 E380RR53
ELECTRODES FOR WELDING MILD AND MEDIUM TENSILE STEELS PH 27 Austarc 16TC PH 56S PH 56R PH C6H PH 77 KV3
E7048 H4 E7016-1 H8 E7016 H8 E7016 E7028 H4 E7018-1 H8 AWS A5.5:1996 E8015-B3L H4
E4848-3 H5 E4816-5 H10 E4816-4 H5 E4816 E4828-2 H5 E4818-5 H5 AS/NZS 1553.2:1999 E6215-B3L
E383B31 E385B12 E384B12 E382B4 E382B73 E385B32 BSEN 1599:1997 ECrMo2LB22HS
ELECTRODES FOR WELDING LOW ALLOY STEEL AND SPECIAL APPLICATIONS Weldwell PH 27P PH 75
AWS A5.5:1996 E8018-G H8 E7016-C1L H8
AS/NZS1553.2:1999 E5548-G H5 E4816-C1L H10
BSEN499:1995 E463B31 E3862NIB32
ELECTRODES FOR WELDING HIGH TENSILE STEEL PH 118
E11018-G H4
E7618-G H5
BSEN757:19997 E69xMn2NiCrMo
ELECTRODES FOR CREEP RESISTING STEELS Weldwell KV3 KV4 KV5
AWS A5.5:1996 E8015-B3L H4 E8015-B6 H4 E7015-B2L H4
AS/NZS1553.2:1999 E5515-B3L H5 E5515-B6 H5 E4815-B2 LH5
BSEN 1599:1997 ECrMo2LB22H5 ECrMo5B22H5 ECrMo1LB22H5
ELECTRODES FOR WELDING STAINLESS STEEL Weldwell PH RS308LC PH BM310 PH RM316LC Staincord 316L-16 PH RM318LC PH RS309LC PH RS309MoLC PH 22-9-3LR
AWS A5.4:1992 E308L-17 E310-16 E316L-17 E316L-16 E318-16 E309L-16 E309MoL-17 E2209-16
AS/NZS1553.3:1996 E308L-17 E310-16 E316L-17 E316L-16 E318-16 E309L-16 E309MoL-17 E2209-16
2
BSEN 1600:1997 E19.9LR22 E25.20R22 E19.12.3LR22 E19.12.3LR22 E19.12.3NbR22 E23.12LR22 E23.12LR22 E22.9.3NLR22
AWS A5.1 C 2004 AMERICAN CLASSIFICATION Arc Welding Electrodes The American Welding Society classifies electrodes by a letter followed by either four or five digits, eg, the prefix "E" designates ARC WELDING ELECTRODES. Table 1 Electrode Classification A5.1
E6010 E6011 E6012 E6013
A5.1M
Type of Covering
E4310 E4311 E4312 E4313
c
c
Type of Current
F, V, OH, H-fillet F, V, OH, H-fillet F, V, OH, H-fillet F, V, OH, H-fillet
dcep ac or dcep ac or dcen ac, dcep, or dcen
Low-hydrogen potassium, iron powder
F, V, OH, H-fillet
ac or dcep
E6019
E4319
Iron oxide titania potassium
F, V, OH, H-fillet
ac, dcep, or dcen
E6020
E4320
High iron oxide
H-fillet F
ac or dcen ac, dcep, or dcen
High iron oxide
F, H-fillet
ac or dcen
H-fillet F
ac or dcen ac, dcep, or dcen
E6018
E6022
E4318
High cellulose sodium High cellulose potassium High titania sodium High titania potassium
Welding Position
d
E4322
d
E6027
E4327
High iron oxide, iron powder
E7014
E4914
Iron powder, titania
F, V, OH, H-fillet
ac, dcep, or dcen
E7015
E4915
Low-hydrogen sodium
F, V, OH, H-fillet
dcep
E7016
E4916
Low-hydrogen potassium
F, V, OH, H-fillet
ac or dcep
E7018
E4918
Low-hydrogen potassium, iron powder
F, V, OH, H-fillet
ac or dcep
E7018M E7024
c
E7027 E7028
E4918M E4924
c
E4927 c
E7048 Notes: a.
b. c. d.
E4928
c
E4948
Low-hydrogen iron powder
F, V, OH, H-fillet
dcep
Iron powder, titania
H-fillet, F
ac, dcep, or dcen
High iron oxide, iron powder
H-fillet F
ac or dcen ac, dcep, or dcen
Low-hydrogen potassium, iron powder
H-fillet, F
ac or dcep
Low-hydrogen potassium, iron powder
F, OH, H-fillet, V-down
ac or dcep
The abbreviations , F, H-fillet, V, V-down, and OH indicate the welding positions as follows: F = Flat, H-fillets = Horizontal fillet, V = Vertical, progressions upwards (for electrodes 5.0 mm and under, except 4.0 mm and under for classifications E6018 [E4318), E7014 [E4914, E7015 [E4915], E7016 [E4916], E7018 [E4918], E7018M [E4918M], E7048 [E4948]). V-down = Vertical, progression downwards (for electrodes 5.0 mm and under, except 4.0 mm and under for classifications E6018 [E4318], E7014 [E4914], E7015 [E4915], E7016 [E4916], E7018M [E4948],k OH = Overhead (for electrodes 5.0 mm and under, except 4.0 mm and under for classifications E6018 [E4318], E7014 [E4914], E7015 [E4915], E7016 [E4916], E7018 [E4918], E7018M [E4918M], E7048 [E4948]). The term “dcep” refers to direct current electrode positive (dc, reverse polarity). The term “dcen” refers to direct current electrode negative (dc, straight polarity). Electrodes with supplemental elongation, notch toughness, absorbed moisture, and diffusible hydrogen requirements may be further identified as shown in Tables, 2 and 3. Electrodes of the E6022 ([E4322] classification are intended for single-pass welds only.
Table 2 Tension Test Requirementsa, b, c AWS Classification A5.1 E6010 E6011 E6012 E6013 E6018 E6019 E6020 E6022 E6027
Tensile Strength
Yield Strength at 0.2% Offset
A5.1M
A5.1 (ksi)
A5.1M (MPa)
A5.1 (ksi)
E4310 E4311 E4312 E4313 E4318 E4319 E4320 E4322 E4327
60 60 60 60 60 60 60 60 60
430 430 430 430 430 430 430 430 430
48 48 48 48 48 48 48 48
A5.1M (MPa)
330 330 330 330 330 330 330 Not Specified 330
58 490 70 E4914400 E7014 58 490 70 E4915 400 E7015 58 490 70 E4916 400 E7016 58 490 70 E4918 400 E7018 58 490 70 E4924400 E702458 490 70 E4927 400 E7027 58 490 70 E4928 400 E7028 58 d 490 70 E4948 400 d E7048 53 – 72 Note c Note c E4918M 370-500 E7018M Notes: a. Single values are minimum b. Weld metal from electrodes identified as E7024-1 [E4924-1] shall have elongation of 22% minimum. c. Tensile strength of this weld is a nominal 70 ksi [490 MPa]. d. For 2.5 mm electrodes, the maximum yield strength shall be 77 ksi [530 MPa].
3
Elongation Percentage in 4x Diameter Length 22 22 17 17 22 22 22 Not Specified 22 17 22 22 22 17c 22 22 22 24
AWS A5.1 Continued Table 3 Charpy V-Notch Impact Requirements
Limits for 3 out of 5 specimensa
AWS Classification A5.1
A5.1M
Average, Min.
Single Value, Min.
E6010, E6011, E6018 E6027. E7015 E7016b, E7018b E7027, E7048
E4310, E4311, E4318 E4327, E4915 E4916b, E4918b E4927, E4948
27 J at -30oC
20 J at -30oC
E6019 E7028
E4319 E4928
27 J at -20oC
20 J at -20oC
E6012, E6013 E6020, E6022 E7014, E7024b
E4312, E4313 E4320, E4322 E4914, E4924b
Not Specified
Not Specified
Limits for out of 5 specimensb
AWS Classification A5.1
A5.1M
E7018M
Average, Min.
Single Value, Min.
o
E4918M
54 J at -30oC
67 J at -30 C
Notes: a. Both the highest and lowest test values obtained shall be disregarded in computing the average. Two of these remaining three values shall equal or exceed 27 J. b. Electrodes with the following optional supplemental designations shall meet the lower temperature impact requirements specified below: AWS Classification
c.
Electrode Designation
Charpy V-Notch Impact Requirements, Limits for 3 out of 5 specimens (refer to Note a above)
A5.1
A5.1M
A5.1
A5.1M
Average, Min
Single Value, Min
E7016 E7018
E4916 E4918
E7016-1 E7018-1
E4916-1 E4918-1
27 J at -45oC
20 J at -45oC
E7024
E4924
E7024-1
E4924-1
27 J at -20oC
20 J at -20oC
All five values obtained shall be used in computing the average. Four of the five values shall equal, or exceed, 67 J.
Table 7 Chemical Composition Requirements for Weld Metal AWS Classification A5.1
A5.1M
E6010 E6011 E6012 E6013 E6019 E6020 E6027
E4310 E4311 E4312 E4313 E4319 E4320 E4327
E6018 E7015 E7016 E7018
UNSa Number
Weight Percentb
Combined Limit for Mn + Ni + Cr + Mo + V
C
Mn
Si
P
S
Ni
Cr
Mo
V
W06010 W06011 W06012 W06013 W06019 W06020 W06027
0.20
1.20
1.00
N.S
N.S.
0.30
0.20
0.30
0.08
N.S.
E4318 E4915 E4916 E4918
W06018 W07015 W07016 W07018
0.03 0.15 0.15 0.15
0.60 1.25 1.60 1.60
0.40 0.90 0.75 0.75
0.025 0.035 0.035 0.035
0.015 0.035 0.035 0.035
0.30 0.30 0.30 0.30
0.20 0.20 0.20 0.20
0.30 0.30 0.30 0.30
0.08 0.08 0.08 0.08
N.S. 1.50 1.75 1.75
E7014 E7024 E7027
E4914 E4924 E4927
W07014 W07024 W07027
0.15 0.15 0.15
1.25 1.25 1.60
0.90 0.90 0.75
0.035 0.035 0.035
0.035 0.035 0.035
0.30 0.30 0.30
0.20 0.20 0.20
0.30 0.30 0.30
0.08 0.08 0.08
1.50 1.50 1.75
E7028 E7048
E4928 E4948
W07028 W07048
0.15
1.60
0.90
0.035
0.035
0.30
0.20
0.30
0.08
1.75
E7018M
E4918M
W07018
0.12
0.40 to 1.60
0.80
0.030
0.020
0.25
0.15
0.35
0.05
N.S.
Notes: a. SAE/ASTM Unified Numbering System for Metals and Alloys. b. Single values are maximum. N.S. means Non Specified.
4
AS/NZS 1553.1 — 1995 AUSTRALIAN/NEW ZEALAND STANDARD CLASSIFICATION AND DESIGNATION
1.4
1.4.1 Basis of classification Electrodes shall be classified on the basis of the tensile properties of the deposited weld metal and the operational characteristics of the electrodes. An electrode classified under one classification shall not be classified under any other classification. 1.4.2
Designation The designation system is illustrated in Figure 1.1 and shall consist of the following :-
(a)
A letter prefix E, denoting electrode.
(b)
A 2-digit number which represents approximately one-tenth of the allowable minimum tensile strength of the deposited weld metal, in megapascals, in two groupings nominally referred to as E41XX and E48XX (see Table 2.4)).
(c)
A 2-digit number which indicates the welding position or positions in which the electrode is capable of making satisfactory welds, the type of welding current to be used with the electrode and the type of covering on the electrode, in conformity with Table 1.1.
(d)
Optional indicators relating to notch toughness grading, attainable diffusible hydrogen status and coating moisture absorption resistance.
FIGURE 1.1 PRINCIPLES OF DESIGNATION
TABLE 2.1 CHEMICAL COMPOSITION REQUIREMENTS OF DEPOSITED WELD METAL Classification
Chemical Composition, maximum percent
E41XX E48X4 E48X5 E48X6 E48X7 E4818 E48X8
C
S
P
0.15
0.030
0.030
0.15
0.030
Mn*
Si
Ni*
Cr*
Mo*
V*
Values not specified 1.25 1.25 1.60 1.60 1.60 1.60
0.030
E4X99
0.90 0.90 0.75 0.75 0.75 0.90
0.30
0.20
0.30
A
As specified by the manufacturer
* Total of all these elements not to exceed the following: E48X4 E48X5
E48X6 E48X7
1.5 percent
1.75 per cent
E48X8
TABLE 2.4 TENSILE PROPERTIES OF DEPOSITED WELD METAL IN ALL-WELD-METAL TESTS Classification
Tensile strength * MPa
Minimum Yield strength * MPa
Minimum elongation on 5.65/So percent
E41XX
430 to 550 (1)
350 (1)
22
E48XX
(2)
420 (2)
22
500 to 620
5
0.05
AS/NZS 1553.1 Continued TABLE 1.1 WELDING POSITION, CURRENT AND COVERING Third and fourth digit of destination
Welding Position (See Note 1)
10 11
F,V,OH,H F,V,OH,H
12
F,V,OH,H
13
F,V,OH,H
14
F,V,OH,H
15 16
F,V,OH,H F,V,OH,H
18
F,V,OH,H
19
F,V,OH,H
20
F,H-fillet
24
F,H-fillet
27
F,H-fillet
28
F,H-fillet
46
F,V-down OH,H F,V-down OH,H As specified by manufacturer
48 99
Type of current and polarity (see Note 2)
dc electrode positive ac or dc electrode positive ac or dc electrode positive or negative ac or dc electrode positive or negative ac or dc electrode positive or negative dc electrode positive ac or dc electrode positive ac or dc electrode positive ac or dc electrode positive or negative ac or dc electrode positive or negative ac or dc electrode positive or negative ac or dc electrode positive or negative ac or dc electrode positive ac or dc electrode positive ac or dc electrode positive As specified by manufacturer
Type of covering and slag
High cellulose High cellulose High titania viscous slag High titania fluid slag Low iron powder, titania Hydrogen controlled, basic Hydrogen controlled, basic Hydrogen controlled, basic Low iron powder Iron oxide titania potassium High iron oxide High iron powder, titania High iron powder, iron oxide Hydrogen controlled high iron powder, basic Hydrogen controlled, basic Hydrogen controlled, basic Low iron powder As described by manufacturer
NOTES: 1. The abbreviations F, V, V-down, OH, H, H-fillet indicate the following welding positions, as defined in AS 2812 and AS 3545. F = Flat V = Vertical V-down = Vertical down OH = Overhead H = Horizontal H-fillet = Horizontal fillet (position 2F in AS 3545) 2. See Appendix A for possible exceptions.
TABLE 2.5 AVERAGE IMPACT ENERGY VALUES-DEPOSITED WELD METAL 1
2
3
4
5
Grade
Testing Temperature
Minimum average value of a set of 3 specimens
Minimum individual value
Minimum average value before rejections
(oC)
(J)
(J)
(J)
No requirement 20 0 -20 -30 -40 -50 -60
No requirement
No requirement
No requirement
47
31
40
Z A 0 2 3 4 5 6
6
Section One Arc Voltage: The voltage across the welding arc. Arc Blow: This is peculiar to DC. The arc, instead of playing steadily on one spot, is deflected away from point of welding by influence of surrounding magnetic fields. Backing Strip: Material (metal, carbon, ceramic, etc) backing up a joint during welding to help obtain a sound weld. (See Fig 1.) Buffer (or Butter) Layer: Layer of weld metal on component to prevent crack formation or dilution effects in subsequent weld layers, (eg hardfacing, cast iron). Cold Crack: Crack occurring in weld metal or in the heat-affected zone of the base metal after cooling. Concave Fillet: Fillet weld having concave face. (See Fig. 2.) Convex Fillet: Fillet weld having convex face. (See Fig. 3.) Crater: Depression at the termination of weld bead. Crater Crack: Crack in weld bead crater. Depth of Fusion: Distance that fusion extends into base metal. (See Fig. 4.) Dilution: Admixture of base metal and weld metal being deposited. Earth (or Work) Lead: Cable between workpiece and power source. Electrode Lead: Conductor between source of current and electrode holder. Flux: Fusible material coated onto electrodes for removal of oxides and other impurities. (See section, ‘The Welding Electrode”.) Fusion: The melting together of filler metal and base metal, resulting in coalescence. Haloes or “Fish-eyes’: Small, shiny, circular areas displayed on the surface of weld metal after fracture by a tensile stress. Hardfacing: The process of covering wearing areas with wear-resistant metal by welding. Heat-affected Zone: The region beneath the weld bead which has not melted, but whose mechanical properties or micro-structure has been altered by the heat of welding. (See Fig. 4.) Hot Crack: Crack occurring in weld metal soon after solidification conimences. Intermittent Welding: Welding, wherein continuity is broken by recurring unwelded spaces. (See Figs. 5 and 6.) Interpass Temperature: In a multiple run weld, the temperature of deposited metal before the next pass is started. Lack of Fusion: A weld fault wherein adequate fusion of weld and base metal is not obtained. (See Fig. 60, p. 15.) Leg of Fillet Weld: Distance from root ofjoint to toe of fillet weld. (See Fig. 10,p.8.) Mitre Fillet: Fillet weld in which the face of the weld is approximately flat. (See Fig. 7.) Open-circuit Voltage: Voltage between terminals of power source when it is energised, but current is not flowing. Overlap: Protrusion of weld metal beyond bond at toe of weld. Parent Metal: The metal to be welded. Pass: A single welding run along a joint or weld deposit. The result of a pass is a weld bead. Peening: The mechanical working of metals by relatively light hammering. Penetration: The depth a weld extends into a joint from base metal surface. (See Fig. 8, p. 8.) Porosity: Gas pockets or voids in metal. Post-heating: Application of heat to the weldment after welding is completed. Preheating: Application of heat to the base metal before welding commences.
7
WELDING FUNDAMENTALS DEFINITIONS OF ARC WELDING TERMS
Reinforcement of Weld: Weld metal lying outside the plane joining the toes of a weld. (See Fig. 10.) Reverse Polarity: Arrangement of DC arc welding leads wherein the work is the negative pole and the electrode is the positive pole of the welding arc. Root of Weld: The zone on the side of the first run farthest from the welder. (See Figs. 10 and 11.) Root Face: Unbevelled or ungrooved portion of a fusion face at the root. (See Fig. 11.) Slag Inclusion: Non-metallic solid material trapped in weld metal or between weld and base metal. Spatter: Metal particles expelled during welding which do not form part of the weld. Straight Polarity: Arrangements of DC arc welding leads wherein the work is the positive pole and the electrode is the negative pole of the welding arc. Tack Weld: Small weld made to hold parts in proper alignment until final welds are made. (See Fig. 45, p. 13.) Throat Thickness (See Figs. 10 and 11): The minimum thickness of weld metal in: (a) Fillet weld, measured along a line passing through the root. (b) Close square butt joint, measured in the plane of abutting faces. (c) Open square butt weld, measured in centre of original gap parallel to fusion faces. Effective Throat Thickness: Dimension arbitrarily adopted as throat thickness for design purposes. Toe: Boundary between weld face and parent metal between weld faces. (See Figs. 10 and 11.) Underbead or Hard Zone Crack: Crack in the heat-affected zone which may or may not extend to surface of base metal. (See Fig. 72, p. 18.) Undercut: A groove melted in the base metal adjacent to the toe of a weld, and left unfilled by weld metal. (See Figs. 54 and 55, p. 14.) Weave Bead: Weld bead made with slow oscillating motion of the electrodes. Welding Sequence: The order of making welds in a weldment. (See Figs. 12-16.)
8
ADVANTAGES OF WELDING:
ARC WELDING THE PROCESS
Some of the advantages that welding has over riveting and casting methods of assembly are as follows: 1. Welding is usually a cheaper process than riveting for any particular joint, and the joint can often be made much more quickly. 2. It gives a stronger joint and permits the use of less material, thus reducing the weight and cost of the structure. 3. Weld seams are normally pressure tight, and do not need caulking as do riveted joints. Joints are smooth, which is important in many applications. For example, painting is much easier on welded joints, and turbulence in pipes is reduced. 4. Designs not practicable for riveting may be constructed by welding. 5. Plate preparation for welding is generally cheaper than for riveting. 6. Labour necessary can often be cut to less than onethird of that necessary for riveting. 7. Welding is not as noisy as riveting, and permits building and alterations to proceed with the least disturbance to occupants. 8. Welding is more versatile than casting; changes can be made quickly without having to produce a new pattern. 9. Rolled section is often cheaper than cast section, and fabrication by welding of rolled section may be cheaper than casting the same article. 10. No storage of patterns is necessary for welding, as with castings. 11. Articles of consistent and known quality can be produced by welding, whereas castings may have external or hidden internal flaws causing their rejection, or failure in service.
FUSION WELDING is really a melting and casting process in miniature, the various components of the welding process (base metal, weld metal slag, etc) forming the crucible and contents of a tiny electric furnace. The electric arc, with a temperature of the order of 6,000oC, is a concentrated and efficient source of heat. This heat is utilised in the metal arc welding process by employing a flux-coated electrode to provide filler metal. The electrode and parent metal act as poles of the arc, the core wire of the electrode melting and being transferred across the arc to coalesce with the molten parent metal and form a bond which in most cases, is stronger than the parent metal. The flux covering melts more slowly than the core wire and a cup is formed at the electrode tip which assists in directing the molten droplets to the required spot. The weld metal itself, as deposited, has a cast structure, its composition is determined by the core wire and coating of the electrode, and by the amount of pick-up of parent metal during welding. For example, a deposit of alloy steel, say, stainless steel on mild steel, no longer has just the properties expected of that alloy, due to dilution with the parent metal. This effect, in many cases, is not important, but, if desired, it may be eliminated by using multi-layer welds. Welding on materials that have been strengthened by heattreatment or cold-working generally creates a zone of lower strength along the weld boundary. This may not affect the serviceability of the welded joint, but sometimes it is necessary to restore this strength by further heat-treatment or cold-work.
WELDING EQUIPMENT BESIDES THE welding machines and suitable electrodes, the accessories necessary for a welder are: 1.
A substantial work table with a fairly heavy mild steel plate for a top.
2.
Leads. Two are required — one from the machine to the electrode holder, called the electrode lead, and one from the job or work table back to the machine to complete the circuit, called the work or earth lead. These leads should be heavy enough to carry the required current without overheating. They must be kept in good condition and in close electrical contact with the holder and the work for the best utilisation of current.
3.
Electrode Holders. These should be heavy enough not to overheat and have well-insulated handles to avoid electric shocks and accidental arcing. Holders are available that are designed for continuous welding at high amperages. These are fully insulated and the jaws are made of metals having high heat conductivity.
4.
Shields. These are necessary for protecting the eyes and face from glare and ultra-violet radiation from the arc, and spatter from the weld pool. Special tinted glass is used in the shields to absorb ultra-violet rays. A clear piece of replaceable glass is used in front of the coloured glass to protect it from spatter and smoke. 9
5.
Clothing. Leather gauntlets and apron should be worn, and clothes should be of material that will deflect spatter and sparks.
6.
Chipping Hammer. Used for deslagging of welds.
7.
Wire Brush. Used for removing rust, cleaning slag off welds, etc.
THE WELDING ELECTRODE METAL ARC welding electrodes consist of a core wire surrounded by a flux coating. The flux coating is usually applied to the core wire by an extrusion process, but a few types of electrodes are still made by dipping the core wire into a thick slurry of fluxing material and drying out between the application of successive layers. It is important, for uniform running qualities, for the flux coating to be concentric with the core wire, and the extrusion process allows close control to be kept over this. The coating on arc welding electrodes serves a number of purposes: 1. To provide a gaseous shield for the weld metal, and preserve it from contamination by the atmosphere whilst in a molten state. 2. To provide a steady arc by having "arc stabilizer" present, which provide a bridge for current to flow across. 3. To remove oxygen from the weld metal with "deoxidizers". 4. To provide a cleansing action on the work piece and a protective slag cover over the weld metal to prevent the formation of oxides while the metal is solidifying. The slag also helps to produce a bead of the desired contour. 5. To introduce alloys into the weld deposits in special type electrodes, eg the Weldwell hardfacing electrodes, which have mild steel core wire, but contain alloys in the coating. A wide variety of ingredients are used in the coating of arc welding electrodes. Among them are the minerals limestone, fluorspar, silica, rutile and feldspar for slag and gas shield formation, ferro-manganese and ferro-silicon for deoxidation of the weld metal; ferro-chromium, ferro-molybdenum and nickel powder to introduce alloys for hardening and raising the tensile strength of steel weld metal; potassium and sodium silicates (water glass) to bind the particles together and cause them to adhere to the core wire.
STORAGE OF ELECTRODES: Electrodes not stored in a dry place will absorb moisture from the atmosphere. Dampness in electrodes may have some of the following effects: 1. Fiery arc. 2. Excessive spatter. 3. Porosity in weld metal. 4. Spalling of flux coating. 5. Blistering of electrode tip. 6. High arc voltage. 7. Introduction of hydrogen into the weld metal, with increased danger of hard zone cracking on hardenable steels. 8. Formation of white "fur" on flux coating. In most cases this does not have any deleterious effect. Mild steel electrodes may be stored in a warm, dry room. Low hydrogen and some special electrodes (eg stainless steel) require to be stored in a proper heated cabinet if the best results are to be achieved. Provided the temperature of the cabinet is 10oC above that of the outside air, and some ventilation is allowed, the electrodes cannot pick up moisture. Mild steel electrodes which have become damp should be redried at 120oC for 15-30 minutes. Lowhydrogen electrodes should always be dried at the temperature recommended for that particular electrode.
be made the positive pole. The greater amount of heat generated at the work piece in this way assists the welding operation, especially when the components have a heavy mass. Proper fusion and good penetration are assured in this way. If on the other hand, the electrode is connected to the positive pole, the greater heat generated at the electrode tip results in a faster burn-off rate and the electrode is deposited more quickly. This increase in deposition rate, however, may not amount to more than 5 percent and the advantage gained in this way is offset by the reduction in depth of penetration obtained with the resulting weld deposit. The burn-off rate with AC supply is approximately the same for DC supply with the electrode connected to the negative pole.
THE WELDING CURRENT BOTH DIRECT and alternating currents may be used for arc welding. However, most work on mild steel is done using AC. AC welding machines have several advantages over DC machines, among them being a lower purchase cost, higher operating efficiency and negligible maintenance. The quality of welds produced using AC is equally as good as when DC is used. However, AC is limited in that it will not satisfactorily run many of the non-ferrous types of electrodes. The open-circuit voltage of an AC machine is important, because some electrodes need a fairly high voltage to prevent the arc cutting out during welding. The opencircuit voltage depends on the design of the machine.
Most of the non-ferrous and stainless steel electrodes should be connected to the positive terminal, but this is recommended because of the greater arc stability obtained.
The question of open-circuit voltage is not so important with DC machines, since there is not the constant reversal of current necessitating continual re-establishment of the arc.
ARC BLOW: This is peculiar to DC. The arc, instead of playing steadily on one spot, is deflected away from the point of welding due to the influence of surrounding magnetic fields created by welding currents flowing in the work. It may often be overcome or minimised by shifting the earth clamp to another part of the work piece.
When using AC it does not matter to which terminal the electrodes and the work piece are attached, but when DC is used more heat is produced at the positive pole with most electrode types and the manufacturers' recommendations for the most suitable polarity should be followed. With the welding of mild steels, although either polarity can be employed, it is usual for the work piece to 10
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WELDING TECHNIQUES A Word to Beginners
FOR THOSE who have not yet done any welding, the simplest way to commence is to run beads on a piece of scrap plate. Use mild steel plate about 12 mm thick and a 4.0 mm electrode. Clean any paint, loose scale or grease off the plate and set it firmly on the work bench so that welding can be carried out in the downhand position. Make sure that the earth clamp is making good electrical contact with the work, either directly or through the work table. For light gauge material, always clamp the earth lead directly to the job, otherwise a poor circuit will probably result. ELECTRODE C TYPE AND SIZE: The type of electrode will depend on the material to be welded and the position in which welding is to be carried out (ie whether downhand, vertical or overhead). In this case, the general purpose PH28 electrode is the most suitable. We have already chosen a 4.0 mm electrode, but for other jobs the size will depend on the thickness of the material and the type of joint to be welded. For example, on thin material a small size is required, otherwise holes will burn through. The electrode size should allow for adequate root penetration. On vee butt joints, the root run is often made with 4.0 mm or 3.2 mm electrodes and the remaining welding is done with 5.0 mm electrodes. Generally, the maximum size which may be used on vertical and overhead welding is 5.0 mm, but these more specialised applications can be left for the moment while we concentrate on downhand welding. AMPERAGE: Suitable amperages for the various sizes of electrodes are usually printed on the packets. These amperages may be varied to suit conditions C welds on thin plate require low amperages to prevent burn-through, while high welding rates or deep penetration of the weld metal require higher amperages. For 4.0 mm set the machine at about 170 amps. There are several effects produced by incorrect amperage. If it is too high, spatter becomes excessive, and the weld pool becomes very hot, producing a flattened bead with elongated ripple marks, and the electrode overheats. If the current is too low, it is difficult to maintain the arc and prevent the electrode from sticking, the bead is high and rounded, with poor edge fusion, and penetration is slight. Figures 41, 42 and 43 show the effects of different amperages. THE WELDER: Place yourself in a comfortable position before beginning to weld. Get a seat of suitable height and do as much work as possible sitting down. Don't hold your body tense. A taut attitude of mind and a tense body will soon make you feel tired. Relax and you will find that the job becomes much easier. You can add much to your peace of mind by wearing a leather apron and gauntlets. You won't be worrying then about sparks setting alight your clothes. Place the work so that the direction of welding is across, rather than to or from your body. The electrode holder lead should be clear of any obstruction so that you can move your arm freely along as the electrode burns down. if the lead is slung around the back of your neck and over your shoulder, it allows greater freedom of movement and takes a lot of weight off your hand. Be sure the insulation on your cable and electrode holder is not faulty, otherwise you are risking an electric shock. STRIKING THE ARC: Practise this on a piece of scrap plate before going on to more exacting work. You may at first experience difficulty due to the tip of the electrode "sticking" to the work piece. it is caused by making too heavy a contact with the work and failing to withdraw the electrode quickly enough. A low amperage will accentuate it. This freezing-on of the tip may be overcome by scratching the electrode along the plate surface in the same way as a match is struck. As soon as the arc is established, withdraw the electrode very slightly (2.0 mm) from the plate and feed it into the weld pool as it melts down. (See Fig. 44.) Another difficulty you may meet is the tendency, after the arc is struck, to withdraw the electrode so far that the arc is broken again. A little practice will soon remedy both of these faults. ARC LENGTH: The securing of an arc length necessary to produce a neat weld soon becomes almost automatic. You will find that a long arc produces more heat. A very long arc produces a cracking or spattering noise and the weld metal comes across in large, irregular blobs. The weld bead is flattened and spatter increases. A short arc is essential if a high quality weld is to be obtained, although if it is too short there is the danger of it being blanketed by slag and the electrode tip being frozen in. If this should happen, give the electrode a quick twist back over the weld to detach it. Contact or "touch-weld" electrodes do not stick in this way, and make welding much easier.
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RATE OF TRAVEL: After the arc is struck, your next concern is to maintain it, and this requires moving the electrode tip toward the molten pool at the same rate as it is melting away. At the same time, the electrode has to move along the plate to form a bead. The electrode is directed at the weld pool at about 20o from the vertical. The rate of travel has to be adjusted so that a well-formed bead is produced. If travel is too fast, the bead will be narrow and strung out and may even be broken up into individual globules. If the travel is too slow, the weld metal piles up and the bead is too large. MAKING WELDED JOINTS: Having attained some skills in the handling of an electrode, you will be ready to go on to make up welded joints. BUTT WELDS: Set up two plates with their edges parallel, as shown in Fig. 45, allowing a 1.6 mm gap between them and tack weld at both ends. This is to prevent contraction stresses from the cooling weld metal pulling the plates out of alignment. Plates thicker than 6.0 mm should have their mating edges bevelled to form a 70-90o included angle. This allows full penetration of the weld metal to the root. Using a 4.0 mm electrode at 170 amps, deposit a run of weld metal on the bottom of the joint. Do not weave the electrode, but maintain a steady rate of travel along the joint sufficient to produce a well-formed bead. At first you may notice a tendency for undercut to form, but keeping the arc length short, the angle of the electrode at about 20o from vertical, and the rate of travel not too fast, will help to eliminate this. The electrode needs to be moved along fast enough to prevent the slag pool from getting ahead of the arc. To complete the joint in thin plate, turn the job over, clean the slag out of the back and deposit a similar weld. Heavy plate will require several runs to complete the joint. After completing the first run, chip the slag out and clean the weld with a wire brush. It is important to do this to prevent slag being trapped by the second run. Subsequent runs are then deposited using either a weave technique or single beads laid down in the sequence shown in Fig. 12. The width of weave should not be more than three times the core wire diameter. When the joint is completely filled, the back is either machined, ground or gouged out to remove slag which may be trapped in the root, and to prepare a suitable joint for depositing the backing run. If a backing bar is used, it is not usually necessary to remove this, since it serves a similar purpose to the backing run in securing proper fusion at the root of the weld. FILLET WELDS: These are welds of approximately triangular cross-section made by depositing metal in the corner of two faces meeting at right angles (Fig. 35). A piece of angle iron is a suitable specimen with which to begin, or two lengths of strip steel may be tacked together at right angles. Position the angle iron so that the two legs are at 45o to the bench and run in a weld bead using a similar technique as for butt welds, using a 4.0 mm electrode at 170 amps. When you are familiar with this, position another piece of angle iron with one leg horizontal and the other vertical. This is known as a horizontal-vertical (HV) fillet. Strike the arc and immediately bring the electrode to a position perpendicular to the line of the fillet and about 45o from the vertical. Some electrodes require to be sloped about 20o away from the perpendicular position to prevent slag from running ahead of the weld. (See Fig. 46.) Do not attempt to build up much larger than 6.0 mm leg length with a 4.0 mm electrode, otherwise the weld metal tends to sag towards the base, and undercut forms on the vertical leg. Multi-runs can be made as shown in Fig. 47. Weaving in HV fillet welds is undesirable. VERTICAL WELDS: Vertical up. Tack weld a 1 metre length of angle iron to your work bench in an upright position. Use a 4.0 mm electrode and set the current at 140 amps. Make yourself comfortable on a seat in front of the job and strike the arc in the corner of the fillet. The electrode needs to be about 10o from the horizontal to enable a good bead to be deposited. (See Fig. 48.) Use a short arc, and do not attempt to weave on the first run. When the first run has been completed deslag the weld deposit and begin the second run at the bottom. This time a slight weaving motion is necessary to cover the first run and obtain a good fusion at the edges. At the completion of each side motion, pause for a moment to allow weld metal to build up at the edges, otherwise undercut will form and too much metal will accumulate in the centre of the weld. Fig. 49 illustrates multi-run technique and Fig. 50 and 51 show the effects of pausing at the edge of weave and of too rapidly weaving.
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Vertical down. To execute this method, it is advisable to use electrodes which are designed to have a very quick freezing slag. Generally higher amperages are used with fast travel speeds. The easiest type to use when learning is the contact PH C18. The electrode is pointed slightly upward at approximately 80o and when the arc is struck, the tip is pressed onto the work and welding commences and advances as the electrode is drawn slowly down the work. OVERHEAD WELDS: Apart from the rather awkward position necessary overhead welding is not much more difficult than downhand welding. Set up a specimen for overhead welding by first tacking a length of angle iron at right angles to another piece of angle iron or a length of waste pipe. Then tack this to the work bench or hold in a vice so that the specimen is positioned in the overhead position as shown in the sketch. The electrode is held at 45o to the horizontal and tilted 10o in the line of travel (Fig. 52 shows this). The tip of the electrode may be touched lightly on the metal, which helps to give a steady run. A weave technique is not advisable for overhead fillet welds. Use a 4.0 mm electrode at 160 amps, and deposit the first run by simply drawing the electrode along at a steady rate. You will notice that the weld deposit is rather convex, due to the effect of gravity before the metal freezes. Second and third runs are deposited in the order shown in Fig. 53.
1. UNDERCUT: THIS REDUCTION in cross section weakens the joint and creates a slag trap.
Cause
Remedy
High amperage.
Reduce amperage.
Arc too long.
Keep shorter arc.
Angle of electrode too inclined to joint face.
Electrodes should not be inclined less than 45o to vertical face.
Joint preparation does not allow correct electrode angle
Allow more room in joint for manipulation of electrode.
Electrode too large for joint.
Use smaller gauge electrode.
Insufficient depositing time at edge of weave.
Pause for a moment at edge of weave to allow build-up. (Weaving is more likely to produce undercut than a straight run. Therefore, where possible, use straight runs.)
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2. SLAG INCLUSIONS: Non-metallic particles trapped in the weld metal are called slag inclusions. They may seriously reduce the strength of the welded joint. Cause Remedy May be trapped in undercut If bad undercut present, clean slag out and cover with run from previous run. from small gauge electrode. Joint preparation too restricted. Allow for adequate penetration and room for cleaning out slag. Irregular deposits allow slag to If very bad, chip or grind out be trapped. irregularities. Lack of penetration with slag Use smaller electrode with trapped beneath weld-bead. sufficient amperage to give adequate penetration. Use suitable tools to remove all slag from corners, etc. Rust or mill scale, preventing Clean joint before welding. full fusion. Wrong electrode for position Use electrodes designed for in which welding is done. position in which welding is done, otherwise proper slag control of slag is difficult. If slag is present in a weld, chip, grind or flame gouge until removed, and re-weld. 3. INCOMPLETE PENETRATION: A gap left by failure of the weld metal to fill the root. Cause
Remedy
Amps too low.
Increase current.
Electrode too large for joint.
Use smaller electrode.
Insufficient gap.
Allow wider gap.
Angle of electrode.
If too inclined, does not give penetration. Keep nearer to right angle to weld axis.
Incorrect sequence.
Use correct build-up sequence. (See Fig. 12.)
4. LACK OF FUSION: Portions of the weld run do not fuse to the surface of the metal or edge of the joint. Cause Remedy Small electrodes used on heavy Use larger electrodes (precold plate. heat may be desirable). Amperage too low. Increase current. Wrong electrode angle. Adjust angle so the arc is directed more into parent metal. Speed of travel. If too high, does not allow time for proper fusion. Scale or dirt on joint surface. Clean surface before welding. NOTE: In overcoming these faults, it is often an advantage if the job can be positioned to allow welding to be done in the downhand position.
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DISTORTION: DISTORTION in some degree is present in all forms of welding. In many cases it is so small that it is barely perceptible, but in other cases allowance has to be made before welding commences for the distortion that will subsequently occur. The study of distortion is so complex that only a brief outline can be attempted here. THE CAUSE OF DISTORTION: 1. Contraction of the weld metal from the molten state to atmospheric temperature. 2. Different rates of expansion and contraction between the metal adjacent to and at a distance from the weld. 1. Contraction of Weld Metal: Molten steel shrinks approximately 11% in volume on cooling to room temperature. This means that a cube of molten metal would contract approximately 2.2 % in each of its three dimensions. In a welded joint, the metal becomes attached to the side of the joint and cannot contract freely. Therefore, cooling causes the weld metal to flow plastically, that is, the weld metal itself has to stretch if it is to overcome the effect of shrinking volume and still be attached to the edge of the joint. If the restraint is very great, as, for example, in a heavy section of plate, the weld metal may crack. Even in cases where the weld metal does not crack, there will still remain stresses "locked up" in the structure. If the joint material is relatively weak, for example, a butt joint in 2.0 mm sheet, the contracting weld metal may cause the sheet to become distorted. 2. Expansion and Contraction of Parent Metal in the Fusion Zone: While welding is proceeding, a relatively small volume of the adjacent plate material is heated to a very high temperature and attempts to expand in all directions. It is able to do this freely at right angles to the surface of the plate (ie "through the weld"), but when it attempts to expand "across the weld" or "along the weld", it meets considerable resistance, and to fulfill the desire for continued expansion, it has to deform plastically, that is, the metal adjacent to the weld is at a high temperature and hence rather soft, and, by expanding, pushes against the cooler, harder metal farther away, and tends to bulge (or is "upset"). When the weld area begins to cool, the "upset" metal attempts to contract as much as it expanded, but, because it has been "upset", it does not resume its former shape, and the contraction of the new shape exerts a strong pull on adjacent metal. Several things can then happen. The metal in the weld area is stretched (plastic deformation), the job may be pulled out of shape by the powerful contraction stresses (distortion), or the weld may crack. In any case, there will remain "locked-up" stresses in the job. Figures 61 and 62 illustrate how distortion is created. OVERCOMING DISTORTION EFFECTS: There are several methods of minimising distortion effects. 1. Peening: This is done by hammering the weld while it is still hot. The weld metal is flattened slightly and because of this the tensile stresses are reduced a little. The effect of peening is relatively shallow, and is not advisable on the last layer. 2. Distribution of Stress: Distortion may be reduced by selecting a welding sequence which will distribute the stresses suitably so that they tend to cancel each other out. See Figures 12 to 16 for various weld sequences. Choice of a suitable weld sequence is probably the most effective method of overcoming distortion, although an unsuitable sequence may exaggerate it. Simultaneous welding of both sides of a joint by two welders is often successful in eliminating distortion. 3. Restraint of Parts: Forcible restraint of the components being welded is often used to prevent distortion. Jigs, positions, and tack welds are methods employed with this in view. 4. Preheating: Suitable preheating of parts of the structure other than the area to be welded can sometimes be used to reduce distortion. Figure 65 shows a simple application. By removing the heating source from a and c as soon as welding is completed, the sections, a, b and c will contract at a similar rate, thus reducing distortion. 5. Presetting: It is possible in some cases to tell from past experience or to find by trial and error (or less frequently, to calculate) how much distortion will take place in a given welded structure. By correct pre-setting of the components to be welded, contractional stresses can be made to pull the parts into correct alignment. A simple example is shown in Figures 63 and 64.
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METALLURGICAL FACTS ABOUT IRON AND STEEL amount of sulphur. The use of either Weldwell 45S or low hydrogen electrodes is recommended to overcome this problem. In making alloy steels, the physical properties depend not only on the elements added, but upon the heat treatment as well. The degree and duration of heat and the rate of cooling have a profound effect upon the hardness and grain structure. Steels which possess marked hardening ability, such as those with over 0.30% carbon, and varying amounts of other elements, harden in proportion to their rate of cooling. Therefore, in welding, the rapid cooling induced by the cold surrounding area causes such steels to become so hard that they are difficult or impossible to machine. Rapid cooling also sets up stresses which unless relieved by later heat treatment, may produce cracks and subsequent failure. To prevent such conditions, the work or parent metal should be preheated and welded while hot, the exact temperature depending upon the type of material and its response to hardening. This permits the weld and adjoining metal to cool more slowly and more evenly, reducing hardness and producing a more uniform grain structure throughout. More is said of this subject under "High Tensile Steels". It should be remembered that the above conditions apply only to steels having more than 0.30% carbon or when other alloys are present. By far the most welded fabrications today are of structural steel — angles, beams, channels, plates, etc — all of which have low carbon and low hardening ability. When alloys are present in such stock the amount is so small as to be negligible as a hardening factor, therefore the precaution of preheating is unnecessary except on heavy sections where the chilling effect would be severe.
PROBABLY 90% or more of all arc welding is done on some alloy of iron. Commercially pure iron is a silver grey, very ductile metal of low tensile strength —too weak for most engineering applications. To give it the necessary hardness and strength other elements, principally carbon, must be added. When the carbon content ranges from 0.10 to 1.5% the material is known as steel — from 2.50 to 4.0%, it is cast iron. In addition to carbon, other alloys are also used to promote strength, ductility and resistance to corrosion, abrasion, and impact; such elements as nickel, chromium, molybdenum, and copper in general increase hardness and enhance the physical properties. They are used extensively in the popular constructional steels. Other elements, such as tungsten and cobalt, are important in the production of high-speed tool steels, not only to increase hardness, but to retain the cutting edge at relatively high temperatures. Elements such as aluminium, titanium, zirconium, vanadium and boron are especially useful in the removal of certain impurities in steel, thus improving its grain structure and response to hardening when heat-treated. As phosphorus and sulphur are generally considered detrimental except in steels where free cutting is a prime requisite, these elements are usually not permitted to exceed 0.05%. In excess of this amount sulphur causes porosity and brittleness in welding. Therefore, it is necessary to exercise care when welding free cutting steels, which have a sulphur content of from 0.09 to 0.20%. Cold finished steels of this type are the cause of much unsatisfactory welding and unfortunately, no simple means, such as the spark test, will disclose the MILD STEEL
THIS IS essentially iron with up to 0.30% carbon alloyed with it, and containing usually between 0.4 and 1% manganese, a little silicon, and small amounts of sulphur and phosphorus as impurities.
WELDING TROUBLES HOT CRACKING: Cause Sulphur, introduced from the steel or surface impurities, causes the weld metal to crack, especially when under restraint. Rigidity of joint which causes the weld metal to hot-tear before completely solidified. Insufficient throat thickness. Current. Too high a welding current will produce a concave weld, and, by over-heating the metal, induce large crystals to form, which are likely to hot-tear. Wide gap to be bridged, making throat thickness narrow.
Remedy Use either Weldwell PH 56S, PH 77 or 16TC electrodes on high sulphur steels. Clean surface if dirty. Re-design to relieve weld joint of severe stresses or use crack-resistant Weldwell PH 56S, PH 77, PH 27 or 16TC. Travel slightly slower to allow greater build-up in throat. Use lower current Closer set-up tolerance, or deposit run of weld each side of gap to close distance
POROSITY Cause High sulphur in the steel will cause porosity due to gas being evolved. Damp electrodes will cause porosity at the beginning of a run. Overdried electrodes. Most electrodes, except the low hydrogen types, require some moisture for best running characteristics. Over-drying will cause porosity towards the end of run Excessive current, which overheats the electrode, sometimes causes porosity. Surface impurities such as oil, grease, paint, etc, will sometimes cause porosity
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Remedy Use Weldwell PH 56S, PH 77 or 16TC on high sulphur steels. Dry electrodes before use. For further details concerning drying of electrodes, check recommendation on electrode data or consult manufacturer. Use lower amperage Clean joint before welding.
HIGH TENSILE AND ALLOY STEELS THESE ARE produced to increase strength without increasing weight, and this is attained by adding alloys, such as manganese, chromium, nickel and molybdenum, or by increasing the carbon content beyond that of mild steel. The result of this is usually to make the steel more difficult to weld satisfactorily.
Hard zone cracks are generally not visible on the surface which makes it essential to use a proper technique to ensure their absence.
EFFECTS OF WELDING: The two most prominent effects of welding these steels are the formation of a hardened zone in the weld area, and, if suitable precautions are not taken, the occurrence in this zone of underbead cracks. HOW TO WELD HARDENABLE STEELS: 1. The Hardened Zone: Let us picture what happens when welding is carried out on a sample of hardenable steel. At the point where the arc is playing, the parent metal is heated to its melting point. Immediately below the molten pool the metal is white hot, with decreasing temperatures further away. When the arc moves on, the cooler metal below the weld bead has a quenching effect on the very hot metal, with the formation of a hard zone. The hardness of this zone depends on a number of factors, among them being: (a) Composition of the base metal. (b) Temperature of base metal. (c) Mass of base metal adjacent to the weld. (d) Heat input (amperage, amount of build-up per electrode.) (b), (c) and (d) will affect rate of cooling and consequent hardness. The effect of this hardened zone is to reduce the ductility of the parent metal in the weld area, and this, in some applications, may lead to failure of the joint.
Reduce hard zone by: 1. Preheating. This slows down the rate of cooling after welding, and reduces the quenching effect on hot metal. The preheat necessary increases with increasing carbon and alloys, and a heavy mass of metal requires a higher preheat than a thin section. 2. Using higher amperage, which produces more heat and slows down rate of cooling. 3. Larger electrode sizes, since they require higher amperages, will also introduce more heat into weld. 4. Larger deposits. Short, heavy runs deposited from each electrode raise the area of welding to a higher temperature and slow down cooling. 5. Post-weld treatment, consists of tempering or softening in a furnace, with torches, or by induction heating, is sometimes used to reduce the hardness of the heataffected zone. Avoid underbead cracking by: 1 Using correct electrodes. The low-hydrogen types, PH 56S, PH 77, 16TC, etc, or austenite types, Elite RSP, Hi Ten 8, etc, should be used. The PH 56S and PH 77 etc coatings have a very low hydrogen content, and are used for welding high tensile steels, with freedom from underbead cracking. The weld metal has high ductility, and excellent impact strength even at very low temperatures. Weldwell Elite RSP or Hi Ten 8 deposit austenitic weld metal which retains hydrogen and prevents it from diffusing into the hard zone. They may be used for welding very hardenable steels with a minimum of preheating. They are also resistant to hot-cracking — a common fault with some austenitic type electrodes.
2. Underbead Cracking: The tendency for underbead cracking to occur is due largely to the presence of hydrogen in the weld metal. When steel is heated to approximately 720oC, the crystal structure changes to a form known as austenite, and in this state it is able to "absorb" appreciable quantities of hydrogen, such as may be introduced from the arc atmosphere. When the steel cools again after welding, the crystal structure transforms from austenite to another form, eg pearlite, bainite or martensite. In this state, the steel cannot retain the hydrogen, which diffuses into microscopic cavities in the heat-affected area, where it remains and builds up tremendous pressure. If sufficient hydrogen is present and the heat-affected zone hard enough, this pressure will cause underbead cracking. If the hardness of the heat-affected zone exceeds 36 Rockwell c there is a danger that underbead cracks will form when ordinary mild steel electrodes are used. It is not necessary for the weld to be under restraint for these cracks to form. Even unrestricted welds, if sufficient hardness develops, will produce underbead cracks.
2. Using preheat, higher amperage, heavy runs, etc. The same precautions used for reducing the hardness of the heat-affected zone also assist in preventing underbead cracks, firstly, because a zone of lower hardness is less likely to crack, and secondly, because slower cooling allows more hydrogen to escape from the weld to the atmosphere.
STAINLESS STEELS TYPES: There is a large range of alloys in the stainless steel series. 1. Plain Chromium Steels:
THESE ARE more accurately called corrosion and heatresistant steels. They are iron alloys which owe their resistance to corrosion and high temperatures to the presence of chromium alone, or chromium and nickel. Small amounts of other alloys, eg titanium, tungsten, molybdenum, niobium (columbium), are sometimes added.
(a) Martensitic Stainless Steels — 12-16% Cr: Used for cutlery, spindles and shafts, and applications where good resistance to corrosion and scaling at high temperatures is desired. Can be hardened by heattreatment.
The effect of chromium is to form a tough, impermeable film of oxide on the steel, which resists further attack by corrodents. If this film becomes damaged it immediately re-forms, and continues its protective action. The presence of nickel, in sufficient quantity, increases this corrosion resistance and also increases the strength of the steel at high temperatures.
(b) Ferritic Stainless Steels — 16-30% Cr: Used where very high temperature scaling resistance is needed. Also have very good corrosion resistance. Common applications are in furnace parts, oil burners, carburising pots, acid containers, etc 18
They are used for a great variety of purposes, eg, in chemical and food plants, gas turbines, furnaces and other high temperature applications. Because of their good corrosion resistance, and, in the case of austenitic steels, work-hardening ability, these types of steels are often used for hardfacing and building-up wearing parts by the arc welding process. It is common practice to use low-cost steels for certain applications, and cover areas subject to corrosion and wear with the appropriate stainless steel weld metal. In this way considerable savings may be effected.
They are not hardened by heat-treatment, and are subject to gain growth at elevated temperatures, which makes them brittle when cool, although they may still be tough at red heat. 2. Austenitic Nickel-Chromium Steels: The most common of this series is the well-known 18/8 Cr-Ni stainless steel. Other compositions contain 25/20 Cr-Ni, 18/12 Cr-Ni, etc. The addition of 2-3% molybdenum increases resistance to corrosion by sulphuric acid. The outstanding properties of these steels are their corrosion and heat-resistance. It is not possible to harden them by heattreatment, but they work-harden rapidly. They are nonmagnetic or only feebly magnetic. HOW TO WELD STAINLESS STEELS:
Possible Cause Restraint
Remedy Design to eliminate restraint at joint or build up larger bead. Type of joint Design to eliminate fillet welds, which are more prone to crack than butt welds. Inadequate penetration Pay attention to welding technique. Design joint to give easy access during welding. Excessive currents Use lower amperage. Large root gap Use small root gap and slower welding speed to give adequate build-up. Bead shape Concave beads are more likely to crack. Hold electrode at smaller angle to give more convex build-up. Fast welding speed Use slower welding speed to give correct build-up over gap. Weld metal Electrodes which deposit wholly composition austenitic weld metal are particularly susceptible to hot-cracking. Weld metal containing a small amount of ferrite is not so likely to crack. For advice on this point, consult the local Weldwell representative or agent. (c) Weld Decay: If the plain Cr-Ni austenitic stainless steels are heated to 500900oC and allowed to cool slowly, they become more easily corrodible. Such a condition exists in the heat-affected zone of a weld on this material, and a band is formed parallel to the weld where corrosion resistance is greatly lowered. This is believed to be due to the removal of chromium, as such from the grain by carbon, and its precipitation as chromium carbide, leaving a chromium-depleted alloy in the area adjacent to the grain boundaries, which is of much lower corrosion resistance. When the steel is immersed in a corroding medium, these low-alloy areas are eaten out, and the grains of metal simply fall apart. Titanium or niobium additions are frequently made to stainless steels and act as "stabilizers". These have a greater "hunger" for carbon than has chromium, and hence the areas adjacent to the grain boundaries are not depleted of chromium. Very low carbon stainless steels are also used to avoid weld decay. If it is necessary to weld unstabilized material, and afterwards to restore corrosion resistance, it may be heated after welding to 1100oC and quenched. This technique is, of course, limited by the size of the job and its tendency to distort. Unstabilised weld deposits may also exhibit weld decay, for example, where one weld crosses another. For this reason, some stainless steel electrodes are also stabilized. Niobium or columbium additions are always used in this case, titanium being unsuitable as this metal is oxidised in the electric arc, and goes into the slag.
1. Straight Chromium Steels: (a) Martensitic Types (12-16% Cr): These steels will harden when welded, and may be too brittle for the service desired. Therefore, a preheat of 400oC, followed by slow cooling after welding, is desirable to keep down the hardness of the heat-affected zone. If possible, tempering at 650-700oC after welding should be carried out on the job to restore toughness. Electrodes: When welding stainless steels, keep a short arc to avoid loss of chromium and other alloys. (b) Ferritic Types (16-30% Cr): These are hot hardened very much by welding, but they suffer from excessive grain growth if raised to high temperatures, and this makes them brittle when they cool again. The amount of grain growth will depend on the time for which the steel is at the high temperature. For the strongest weld joint, use a preheat of 150-200oC. If multi-runs are necessary, the interpass temperatures should not exceed 200oC. Post-weld treatment, consisting of tempering at 700-800oC, helps to restore ductility to the heat-affected zone of the weld. 2. Austenitic Stainless Steels: These are very similar to mild steel to weld. There are a few points of difference. (a) Distortion: Coefficient of expansion is 50% higher than mild steel, and the tendency to distort is consequently much greater. Remedies: Use frequent tack welds. Use balanced and distributed welds to prevent stress from building up, and to spread the heat evenly through the work. Use jigs if possible, to hold the job firm during welding, and also to extract heat from the weld area. Reduce heat input by employing the smallest bead size convenient, and a moderate amperage. A small bead on each side of a plate gives less distortion than a heavy bead on one side. (b) Cracking Certain types of austenitic welds are susceptible to cracking.
MANGANESE STEEL
WELDING OF MANGANESE STEEL The effect on manganese steel of slow cooling from high temperatures is to embrittle it. For this reason it is absolutely essential to keep manganese steel cool during welding. This may be done by skip welding to distribute the heat, or by quenching after each run. Slow cooling from temperatures of over 300oC will embrittle the steel, and a good rule to apply is that the steel should be cool enough to touch with the bare hand before depositing another run.
AUSTENITIC manganese steel, containing 11-14% manganese is used extensively where severe impact, combined with abrasion is met. This steel work-hardens rapidly when subject to impact, and is very suitable for applications such as crusher jaws, digger teeth, dredge bucket lips, railcrossings, etc. Manganese steel is non-magnetic, or feebly magnetic when cold-worked.
Toughness may be restored to manganese steel by heating to 1060oC and quenching.
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ELECTRODES FOR MANGANESE STEELS: For joining and building up manganese steel, use Weldwell RSP, which deposits 18/8Mo stainless steel weld metal. The RSP deposit acts as a buffer between the manganese steel and the final deposited weld metal, which can be PH Mn or any of the hardfacing alloy types. CAST IRONS THESE MAY be conveniently divided into the following groups: (a) Grey iron, which contains between 2.5 and 4% carbon, mainly in the form of flake graphite, and high silicon. This iron is relatively soft. Made by slow cooling of the casting. (b) White iron, of similar composition to grey iron, but having most of the carbon present in the form of intensely hard and brittle cementite, or iron carbide. The silicon content is lower. Made by rapidly cooling the casting with "Chills". (c) Malleable irons, white heart and black heart. These are white cast irons which have been heat-treated to render them more ductile than grey irons. (d) Alloy cast irons. These are made for wear, corrosion and heat-resistance, and for extra strength. Examples are "NiResist" (corrosion resistance), "Nicrosilal" (heat resistance), and "Meehanite" (high tensile). Some of these cast irons contain sufficient alloys to make them austenitic. (e) Spheroidal graphite cast iron (SG iron, ductile cast iron, nodular cast iron). This is a recent development in the search for high strength cast iron. By the addition of a small amount of magnesium (generally as nickel-magnesium alloy) during tapping into the ladle the graphite is made to form in minute spheres instead of the usual flake form when the casting cools. The result is a cast iron which, in the annealed state, has mechanical properties similar to those of mild steel. WELDING OF CAST IRONS: All of the cast irons, except white iron, are weldable. White iron, because of its extreme brittleness, generally cracks when attempts are made to weld it. Trouble may also be experienced when welding white-heart malleable, due to porosity caused by gas held in this type of iron. It is safer to braze weld using oxyacetylene and Lo-fuming bronze. PRECAUTIONS WHEN WELDING CAST IRONS: The factors to consider when welding cast irons are similar, whatever the types. They are: 1. Low ductility, with a danger of cracking due to stresses set up by welding. (This is not so important when welding SG iron due to its good ductility.) 2. Formation of a hard, brittle zone in the weld area. This is caused by rapid cooling of molten metal to form a white cast iron structure in the weld area, and makes the weld unsuitable for service where fairly high stresses are met. 3. Formation of a hard brittle weld bead, due to pick-up of carbon from the base metal. This does not occur with weld metals which do not form hard carbides, such as "Monel" and high nickel alloys. These are used where machinable welds are desired. PREHEATING:Although a large amount of satisfactory welding is done without preheating, cracking due to the rigidity or lack of ductility of castings, especially complicated shapes, may be minimised by suitable preheating. 1. Local Preheating: Parts not held in restraint may be preheated to about 500oC in the area of the weld, with slow cooling after welding is completed. 2. Indirect Preheating: By this is meant that in addition to the local 500oC preheat, a preheat of about 200oC is given to other critical parts so that they will contract with the weld and minimise contraction stresses. Such a technique is suitable for open frames, spokes, etc. (See Fig. 73.)
Weldwell PH Mn is designed to produce a 13% manganesecontaining weld metal which is very tough and dense, with a high yield and tensile strength. It work hardens and withstands heavy impact loads. Mild steel electrodes should not be used, because dilution with base metal produces a very brittle weld.
3. Complete Preheating: For intricate castings, especially those having varying section thicknesses such as cylinder blocks, it is advisable to completely preheat to 500oC followed by slow cooling after welding. A simple preheating furnace may be made of bricks, into which gas jets project, or filled with charcoal which burns slowly and preheats the job evenly. In these cases gas welding is often preferred to the use of arc electrodes. PRINCIPLE OF INDIRECT PREHEATING
POST-HEATING: After any welding on cast iron the slowest cooling possible should be allowed, the part either remaining in the preheating furnace or cooling under a blanket of insulating powder or sand. It is sometimes the practice to post-heat welded joints to relieve stresses and so soften hard areas. This is done with torches or in the furnace. PEENING: Satisfactory welds may be made on cast iron without preheating by using electrodes depositing soft metal and peening the weld with a blunt tool (such as a ballhammer) immediately the weld is deposited. This spreads the weld metal and counteracts the effect of contraction. Deposit short weld runs (about 50mm at a time) and then peen before too much cooling takes place. Supercast Ni or Supercast NiFe are soft and allow peening. WELDING PROCEDURE: Clean the area to be welded of all grease, sand, etc before welding commences. Oil-impregnated castings should be heated to burn out all oil, otherwise porosity and poor weld bonds will result. "Gassy" castings will also produce porosity in the weld metal. This may be overcome by heating the weld area to a dull red for a short time before welding or by buttering the faces of the contaminated casting with Austarc 16TC. Preheat, if necessary, to the desired temperature. If preheating is employed, use the largest electrode suitable for the job and build up the deposits to the maximum crosssectional size. The weld is then more able to withstand stresses set up on cooling. When the casting is not preheated, use small gauge electrodes and scatter the runs to disperse the heat and cooling stresses. To repair cracked castings, drill a hole at the end of the crack to prevent it spreading further, and grind out to the bottom. Begin welding at the drilled end of the crack, where restraint is greatest, and move towards the free end. Castings which have to transmit fairly heavy working loads often have the weld joint assisted by mechanical means such as bolted straps, or hoops which are shrunk on. Broken teeth of large cast iron gears are sometimes repaired by studding. Holes are drilled and tapped in the face of the fracture, and mild steel studs screwed in. These are then covered with weld metal and built up to the required dimensions. They are afterwards machined or ground to shape.
STUDDED GEAR WHEEL TOOTH 20
NON-FERROUS METALS (a) ALUMINIUM: ALUMINIUM AND its alloys, because of their lightness, corrosion resistance and strength, are finding increasing use in chemical plant and structural work. They are made in wrought and cast forms. The alloys may be (a) heat-treatable (containing small amounts of silicon, copper, magnesium, chromium and zinc) and obtain their strength by quenching and age-hardening, or (b) non-heattreatable (containing mainly manganese and magnesium) and depend on cold-working for extra strength. Welding of Aluminium: Aluminium is very different to steel in its properties and weldability because ... it has a melting point of 660oC (800oC lower than steel), but requires as much heat per pound to melt it; it has a thermal conductivity five times that of steel, hence heat loss is rapid, making a preheat necessary; it expands twice as much as steel for a given temperature increase, with greater danger of distortion; it forms a tough, adherent oxide film on its surface which prevents globules of molten weld from "wetting" the plate; it absorbs hydrogen readily when molten, but rejects it on solidification, creating a danger of porosity. Hints for the Welder: 1. When welding all but very thin sections, use a preheat to ensure proper fusion of weld with the base metal, and use copper backing if necessary. 2. Allow for high rate of expansion when setting up jobs. If possible, use jigs to prevent distortion and employ frequent tack welds. 3. Design joints so that the weld has the least possible restraint placed on it to avoid hot-cracking. Butt welds are generally stronger than fillet welds, because of more uniform stress distribution. They are also better than fillet welds in chemical plants because they are easier to clean and less likely to trap corrosive slag. 4. Keep all aluminium type electrodes in a warm, dry place, and dry at 150oC for half an hour before use.
HARDFACING THE PROCESS of covering wearing areas with wearresistant metal by welding is known as hardfacing. It has a wide application in all fields of industry, and its intelligent use results in longer, more efficient machine life, less down time and less maintenance costs. It is becoming common practice to make wearing parts of cheaper steels and to hardface the wearing areas, thus conserving expensive alloy steels, and still obtaining results that are as good or better than these steels give. Stainless steel overlays on mild steel for corrosion resistance are often employed. TYPES OF WEAR: There are two main types of wear. 1. Shock or impact: The material to resist this kind of wear must be hard enough to resist serious deformation, and yet not so hard as to be brittle and crack under the effect of impact. Electrodes depositing such metal are: (a)
Weldwell RSP produces an austenitic weld metal which work-hardens under impact. This metal is very ductile and does not easily crack.
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5. Clean the surface of the joints with a wire brush just before welding. 6. After welding, the joints must be thoroughly cleaned with a brush and hot water to remove slag. (b) COPPER: Copper, and its alloys, the bronzes and brasses, are in most cases, weldable with the arc. 1. Copper: May be "deoxidized" or "tough pitch" copper. "Deoxidized" copper is welding quality. "Tough pitch" copper is not welded satisfactorily with the arc, due to gross porosity forming in the weld junction. 2. Bronzes: Plain bronzes are alloys of copper and tin. Aluminium bronzes contain up to 11% aluminium, which gives high tensile strengths and excellent corrosion resistance. 3. Brasses: Alloys of copper and zinc, with other alloys added in special cases. Welding of Copper and Alloys: The most important factor is the high rate of conductivity of copper, making a preheat of heavy sections necessary to give proper fusion of weld and parent metal. It also has a high coefficient of expansion — about 35% greater than mild steel — for which allowance must be made in setting up. Hints for the Welder: 1. Preheat to give good fusion. 2.
Insulate to prevent loss of heat.
3. When building up parts such as bronze bearings, cleanse first with petrol to remove oil, dry, and heat to drive oil from cracks. Electrodes recommended by Weldwell: For copper: Bronze Arc. For bronzes: Bronze Arc. For brasses: Bronze Arc. For aluminium: Ally-Arc
(b)
Weldwell PH 250 and PH 400, the deposits of which do not work-harden appreciably, but which are fairly hard and sufficiently ductile to resist cracking. They will not, however, withstand severe impact, since they tend to deform under the blows. PH 400 is better able to resist this than PH 250. The best solution to the problem of resisting very severe impact may be to employ a buffer layer of Elite RSP, followed by a layer of PH 700 or PH 600. PH 700 alone, although depositing a very hard alloy, is suitable for moderate impact conditions. For high impact loads use PH Mn. 2. Abrasion: This is caused by a grinding action of particles against the wearing surfaces, or by rubbing together of surfaces. To resist this type of wear, a relatively hard material is needed, and it often happens that this material is also somewhat brittle and unable to withstand severe impact without cracking. The PH 700 or Abrasocord 43 and Vidalloy 11 electrodes give hard deposits suitable for withstanding abrasion under various conditions.
1.
It is very seldom that either of these two types of wear is found alone; generally both are present in greater or lesser degree, and it is a question then of selecting an electrode that will most satisfactorily cope with both conditions. The PH 700 electrode has been designed to withstand the combined effects of impact and abrasion. Added to these types of wear it sometimes happens that the part in question is also operating under corrosive conditions, and a hardfacing alloy that is able to resist this must be used. The foregoing brief account gives some idea of the range of conditions likely to be met. For specific applications, the Weldwell Technical staff is always willing to offer advice. PRE-HEATING: There are four main reasons for preheating parts to be hardfaced:
2.
To prevent underbead cracking of steels having sufficient carbon or alloys to make them very hardenable. To prevent cracking of rigid, brittle components due to contraction of the weld metal.
3.
To prevent cracking of large areas of the very hard types of hardfacing.
4.
To minimise distortion of the part being welded.
The first point is the most important to watch, since a large amount of hardfacing is done on medium-to-high carbon and alloys steels, and if underbead cracks form the weld deposit may spall off in service. The importance of the other points mentioned depends on the particular application in hand.
CUTTING WITH THE ELECTRIC ARC To cut a section (eg a circle) from a plate a hole is first pierced in it by concentrating the arc at one spot and pushing the electrode into the molten pool until it melts through to the other side. The hole can then be enlarged or extended into a cut as required.
IN ADDITION to welding, the arc can be used for certain other operations such as cutting, piercing, chamfering and gouging of metals. There are two variations of the process C 1. the use of conventional welding electrodes at high currents, and 2. the oxy-arc process.
Back-gouging and grooving of weld joints can also be done with electrodes. As for cutting, a high current is needed. The electrode is inclined at about 5o to the plate surface and pointed in the direction in which the grooving is to be done. The molten metal is pushed ahead of the electrode tip, and periodically the electrode is run back along the groove to clean out slag. It is an advantage also if the job can be positioned so that the slope allows molten material to run ahead clear of the groove. Austarc C&G electrodes are particularly suitable for grooving and clean, neat grooves can be made.
1. Cutting with electrodes: Whereas the gas cutting of steel is a burning action, the metal being oxidised by the oxygen stream and blown away as a molten stream, the arc cutting action depends entirely on the heat of the electric arc to melt the metal, and the force of arc to remove it from the face of the cut. For this reason the arc cutting process can be used on metals such as cast iron, stainless steel and non-ferrous metals, which are not readily oxidizable or which cannot be otherwise cut with the gas process unless the power cutting or plasma arc process is available.
Piecing is best done, where possible, from beneath the job, the molten metal then falling clear of the hole.
Higher currents are used than are needed for ordinary welding purposes. The actual current value will depend on the thickness of metal to be cut. With the electrode held vertical the arc is struck on the edge of the plate and played up and down the face of the cut with a see-saw motion. A long arc is held, which is made possible by the high current, and this causes molten metal to run down the cut. If properly used, no metal will be deposited from the electrode.
Chamfering is performed in a similar manner to cutting. Arc cutting is not as neat as gas cutting; it is intended for use where gas equipment is not available or where materials have to be cut for which the gas cutting process is not effective.
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Section Two TECHNIQUES FOR SELECTED APPLICATIONS New or Slightly Worn Grousers: Cover the working edge with one run of RSP or PH 77 to act as a buffer. Hardface with one run of PH 600. DO NOT apply hardfacing direct to grouser. Use step back sequence at 15 cm runs to reduce distortion. Badly Worn Grousers: Flame cut the tip to a straight edge and weld on build up strip of mild steel or special carbon steel with PH 56S, PH 77 or 16TC, again using step back sequence. Allow sufficient gap for complete penetration. Mild steel may be hardfaced with PH 600 direct. Special steel strip requires buffer of RSP or PH 77 before hardfacing. Track Links: Because of high carbon content of steel, it is desirable to use buffer of PH 56S or RSP for first layer. If RSP is used no other hardfacing is necessary, since this deposit work-hardens to over 400 VPN. PH 400 is used to build up over PH 56S or 16TC. If it is convenient, a preheat of 150oC may be used and PH 400 applied direct to link. In any case, it is an advantage to warm the side of the link opposite the one being welded to counteract the effect of contraction. A jig made up of copper bar, is of great assistance in securing desired shape of weld deposit.
Idler Wheel: Mount the wheel on a shaft for easy manipulation. Weld diametrically opposed segments to reduce distortion. Use PH 56S for first layer and hardface with PH 250 or PH 400.
Drive Sprocket Teeth: Cut a steel template, patterned from a new wheel, covering three or four teeth. The weld deposit can then be checked to see when there is sufficient build-up. PH 56S is used for the first layer to ensure freedom from cracking, and the remaining build-up is done with PH 400.
Track Rollers: Generally made of cast steel and flame or induction hardened on the wearing surface. Method: Mount on shaft for easy turning. Use PH 56S for first run, and PH 400 for build-up. Top rollers are sometimes made of cast iron with white iron wearing surfaces, and are often considered not worthwhile reclaiming. If it is desired to build-up these rollers, use two layers of PH 56S followed by PH 400. Preheat to 500oC before welding commences. Dozer Blade Tips and Wearing Strips: These are made of high carbon steel and it is essential to use a buffer layer. Method: Preheat the blades to 150oC before welding. For blades working under heavy impact as well as abrasion, use RSP buffer on all surfaces to be hardfaced, followed by a layer of PH 600 or PH 700. For abrasive wear only, in sand or clay pits, PH 56S is suitable. A layer of Vidalloy 11 on the corner of the tip greatly helps in preventing this from becoming rounded.
Excavator Buckets: Deposit runs of PH 600 or PH 700 at distances of 25-50 mm apart on all wearing faces. Cover all rivet heads with hardfacing otherwise they wear away very rapidly.
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Scarifier and Ditcher Teeth: Worn Manganese Steel Teeth: Build up with RSP and hardface with PH 600 or PH 700. Do not allow to overheat. New Manganese Steel Teeth: One layer of PH 600 or PH 700. High Carbon Steel Teeth: PH 56S or RSP for buffer layers or build-up. PH 600 or PH 700 for facing layer. Vidalloy 11 prolongs tooth life.
Ploughshares: It is always best to hardface ploughshares before use or when only a little wear has taken place. (a) Cast Iron Ploughshares: Use PH 700 in short runs. (b) Cast Steel Ploughshares: Use PH 600 or PH 700. Only one face of the share requires hardfacing in order to create a self-sharpening edge.
Ripper Teeth: Generally made of manganese steel. Use PH 600 or if build-up needed, use RSP with final layer of PH 700. Do not allow manganese steel to overheat. Vidalloy 11 on the point will give extended life. If teeth are made of high carbon steel apply RSP buffer before hardfacing.
Pump Impellers: Hardface with PH 600 or Abrasocord 43 as shown. Use small electrodes to keep heat input down. The pump casing may also be hardfaced with PH 600 or Abrasocord 43 if not made of cast iron. If casings are cast iron, use Supercast Ni or Supercast NiFe for build-up. 16TC can be used as a buttering run if the casing is contaminated. Excavator and Bucket Teeth: If these are made of manganese steel, use PH 600 or PH 700. Manganese steel must not overheat or it becomes brittle; therefore, scatter the welds or quench to keep cool. If build-up needed, use RSP before hardfacing. For teeth made of high carbon steel, use RSP buffer, followed by PH 600 or PH 700. Provide a self-sharpening edge by covering the upper surface with hardfacing and depositing stringer beads on the underside. The softer base metal wears more rapidly than the hardfacing, thus maintaining a sharp edge, but stringer beads prevent excessive wear. (See Fig. 86b.) If teeth are badly worn, new steel tips are welded on with RSP and hardfaced, as shown in Fig. 86c.
Excavator Doors: Deposit runs of PH 600 at 25 mm intervals as shown in the sketch.
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Dredge Bucket Lips: Hardface lips with PH 600 or PH 700.
Chains (Dragline, etc): Hardface wearing areas with PH 400.
Post Hole Auger: The cutting edge gives best service if hardfaced with Vidalloy 11. Only the upper cutting surface and corners need to be hardfaced, thus providing a self-sharpening edge. The edge of the spiral may be hardfaced with Abrasocord 43 or PH 600 as shown in Fig. 90.
Drill Bits: Preheat to 200oC and apply RSP buffer. Hardface with PH 600. Alternatively use PH 700 alone. Build the corners out so that the drill will not stick in hole.
Oil Drills (Fish Tails): Clean the surface to be welded. Apply Vidalloy 11 to the wearing edge as shown in the sketch.
Oil Drill Collars and Joints: Vidalloy 11 is deposited in bands around collars and joints as shown in Fig. 94, and built out slightly beyond the rest of the metal to give adequate protection.
Mill Hammers: Preheat to 250oC. Build up worn corners with PH 600, PH 700 or Abrasocord 43.
Conveyor Screws: Mount the screw on a shaft for easy turning. Deposit PH 600, PH 700 or Abrasocord 43 on the edge and bearing surface of the screw. For cast iron screws, use RSP or PH 56S deposited in short runs from small gauge electrodes. Hardfacing is generally confined to the edge of the spiral due to the brittleness of cast iron.
Crusher Jaws: Usually made of Manganese Steel. If so, butter the worn surface with RSP, usually two layers thick. Then build up to nearly the required dimension with PH Mn and finish off with either PH 600 or PH 700. Note the usual precautions are maintained, ie "Keep Cool", "Scatter the weld deposits", etc. Usually when depositing PH Mn it is desirable to peen each run thus work hardening the deposit. 25
Grizzlies: Use PH Abrasocord 43, PH 700 or PH 600 along with the wearing edges of the bars. If necessary, deposit a run also in the centre of the bars.
Crusher Liners: May be manganese steel. If so, hardface with PH 600 observing usual cooling precautions. Deposit runs as shown in sketch. For build-up, use RSP before hardfacing.
Crusher Mantles: For build up on carbon steel, use PH 250 or PH 400, followed by PH 600. For building up on manganese steel, use RSP and hardface with PH 600 or PH 700.
Cyclone Fan Blades: Use PH 600. It is essential that the contact sides be completely covered with hardfacing and that the runs be even and completely overlap, because abrasion will quickly enlarge any depression. After welding, balance the blades by grinding off heavy portions.
Pug Mill Knives: More economical to hardface when only a little wear has taken place. Use Abrasocord 43 or PH 700. If building-up necessary, use PH 56S and then hardface with PH Abrasocord 43 or PH 700.
Beater Bar (Swarf Hammer) Use Abrasocord 43 or PH 700. Set face of hammer in mould, preheat to 500oC and cover with hardfacing, using weave. If made of manganese steel do not preheat, butter with RSP then overlay with PH 700. Must be kept cool.
Valves (Liquid): The electrode to be used depends on the material in the valve. For bronze valves use Bronze Arc; for 18/8 stainless steel use PH RM318LC or RS309LC; for cast iron use Supercast Ni; for steel use electrode suitable to resist corrosion being met. For mild corrosive conditions Supercast Ni on steel is suitable; for more severe corrosion use PH RM318LC or RS309LC. After building up as shown in the sketch, machine or grind to shape. Valves and Seats (Liquid and Steam): Machine groove in seating edge and place valve in copper chill, making sure there is sufficient build-up to allow for machining back to desired shape. Electrodes used will depend on composition of base metal (see recommendations for Valves above). Use oxy-acetylene applied Stellite 6 for resisting attack by corrosive liquids at high temperature, and liquids carrying abrasive material. 26
Valve Seating (IC Engine): Machine out groove in valve seat to take weld deposit. A copper chill shaped as in Fig. 107 helps to prevent excessive heat melting the seat, and to retain shape of bead. Use small gauge Supercast Ni or Supercast NiFe. Use short runs and peen.
Valves (IC Engine): Machine groove in seating edge and place valve in copper chill. (See Fig. 108.) Usually done with gas or TIG to deposit Brightray alloy, use arc Hi Ten 8.
Gear Teeth: For repairing broken and chipped gear teeth, use Hi Ten 8. On large gears a slight preheat is desirable. The deposit may be machined back to the desired contour.
Chisels: Chisels may be re-tipped with PH 600 and striking end faced with RSP buffer followed by PH 400. This is very successful in overcoming "mushrooming". New chisels may be made from mild steel bar using the technique described.
Tool Tips: Very satisfactory lathe tools may be made up using mild or low alloy steel shank with a high speed tool steel deposit for the cutting edge. The supporting parent metal beneath the bed should be at least twice the thickness of the high speed tool steel deposit to give adequate strength. Make a mould of copper, carbon or a suitable plastic refractory material to retain the molten deposit on the tip. Puddle the weld metal into the mould until build-up is sufficient and allow to cool in air. Deposit is self-hardening. Shear Blades: A groove is machined on the cutting edge as shown. Blades may be made of mild steel, or a carbon or alloy steel, in which case a preheat is needed, the amount depending on the carbon or alloy content. To avoid distortion in long blades either bolt blades back to back or hold in a suitable restraining jig, and use the step-back sequence of deposition. Building-up should be done with PH 400 and the final hardfacing with PH 600.
Axles and Shafts: Butt break together and tack weld in two places. Cut one vee in crackline with Austarc C & G electrode, clean, then put three runs in with PH 56S. Then vee the other side through to the 56S deposit. Weld with 56S keeping weld area hot, straighten in a lathe or suitable press, let cool in vertical position.
Springs: Prepare a 70o included angle on the broken ends, line up the pieces and weld with Hi Ten 8, a 300oC preheat is desirable. Cool slowly.
27
Section Three WELDWELL WELDING ELECTRODES
ELECTRODES FOR WELDING MILD STEEL
DOWNHAND WELDING
For downhand welding of mild steels where ease of operation and weld appearance is essential the PH 46 is ideal. It has a "rutile coating" which gives a soft arc with the slag following closely to the arc. This slag is compact and has excellent self lifting properties revealing a smooth weld with a nice glossy appearance. The PH 46 has 100% efficiency of deposition and is ideal for sheet metal and general constructional work in medium-thick plate. Where higher deposition rates are desired the PH 22 or PH 7024 type with an efficiency of 140-160% is an ideal choice. They are fast running with quick release slag, very smooth appearance and with very little spatter.
ALL-POSITION WELDING
A large number of often only slightly different rutile-coated all-position electrodes are available on the market. This great variety may make selection of the proper type for the job very difficult. The WELDWELL range of all-position rutile electrodes includes the PH 68, PH 48A, PH 28 and PH 78, each of which has distinctly different properties as a result of difference in arc characteristics, protective gas stream and speed of slag solidification. The strong gas stream and the quickly setting slag makes the PH 68, in particular, suitable for overhead and vertical-down welding, and the metal transfer in the form of relatively large droplets facilitates the bridging of large gaps. The deeper cup and the somewhat finer droplet-transfer of the PH 48A allow this electrode to be welded slightly in touch with the workpiece. It is a somewhat slower setting type than the PH 68, with a rather weak gas stream yielding nice fillet welds in all positions. On account of their quickly solidifying slag the PH 68 and, to a much lesser degree, the PH 48A have a tendency to produce welds with so-called heat indentations if the heat-dissipation is not sufficient, which can be the case when welding joints in thinner plates. On the other hand, their type of slag can take more care of contamination in the form of rust or paint before becoming uncontrollable. The PH 28 is characterised by a cone-shaped cup, a finer droplet-transfer and a slower-setting type of slag. It is the virtual all-position electrode of the series. Heat build-up such as occurs in thin-plate welding, has much less effect on slag behaviour and weld appearance. Compared with PH 28, the PH 78 has a still slower-setting type of slag, which is completely insensitive to heat accumulation in the work piece; there is always sufficient time for the gases to escape from the molten pool before the slag solidifies, resulting in sound welds. Upward welding is favoured by the very nice wash of the weld metal onto the sides, and by the fact that the slag leaves the molten pool very quickly, yet gives sufficient support to the molten pool. The slag is too fluid for vertical-down welding. With this group of all-position electrodes the PH C18 should be mentioned as well. This iron-powder-containing electrode excels in vertical-down welding of fillet joints. Its good penetration properties make it also suitable for spot welding of thin plates.
28
DESCRIPTION: The WELDWELL PH 28 electrode has a medium-heavy rutile coating and yields a fairly rapidly solidifying slag. This electrode is the answer where a universal rod is desired for welding in all positions.
AWS A5.1 AS/NZS 1553.1
The uniform fine-droplet metal transfer and the possibility of using a shorter arc length without risk of short-circuiting and freezing are very helpful in both vertical and overhead welding. The PH 28 may be employed on either AC or DC. When it is used with DC the electrode is normally connected to the negative pole (straight polarity). For this electrode, use can be made of transformers with a relatively low no-load voltage. Applications: Pipe welding on site. Pressure vessels, general construction, hydro installations, ship building. storage tanks.
Welding Positions: F, H, V, OH Recommended Amperages Dia. mm 2.5 3.2 4.0 5.0 6.0
Length Amperes Deposition mm Rate kg/hr* 305 70-100 380 85-135 1.00 380 130-170 1.45 455 190-230 2.15 Available on Special Order only
* Deposition rate at maximum amps. AC 50V DC Typical Mechanical Properties of Weld Metal Tensile Strength Yield Value Elongation(1 = 5d) Impact Value Charpy V Notch at 0oC
500 MPa 448 MPa 26% 52 J
29
E6013 E4112-0
WELDWELL
With this electrode even not so experienced welders will obtain good results since it is very easy to use. The PH 28 is extremely suitable for making fillet welds. Welding is then done with a short arc. The weld surface is very smooth and the beads are almost flat. The same applies for unprepared butt welds and for outside corner welds.
: :
28 ELECTRODES FOR WELDING MILD STEEL TIP COLOUR FLUX MARKING
Blue PH 28 6013 E4112
Approvals: American Bureau of Shipping Lloyds Register of Shipping Bureau Veritas Characteristics Excellent X-ray properties. Quality for wide range of work. High efficiency for vertical and overhead. Smooth arc with very little spatter. Easy to control and for slag removal. Fine for fillet welds. Welding can be done using either AC or DC-. Storage Store electrodes in a dry place. To recondition moist electrodes bake for half an hour at 120oC in a vented oven. Typical Chemical Analysis C 0.04% Mn 0.47% Si 0.40%
DESCRIPTION: Austarc 12P is a smooth running, rutile type electrode for all positional welding of mild steel. It is characterised by a moderately forceful and extremely stable arc, and produces excellent penetration with low spatter losses. Features include :Superb arc striking and restriking on low voltage AC machines. Low spatter levels and self-releasing slag. A stiff, fast freezing slag for all positions (especially vertical down), fillet welding.
AWS A5.1 AS/NZS 1553.1
: :
E6013 E4112-0
WIA AUSTARC 12P ELECTRODES FOR WELDING MILD STEEL
Applications: All positional welding of galvanised gates and fences, steel furniture, trailers, wrought iron work.
TIP COLOUR FLUX MARKING
Austarc 12P is especially recommended for the fillet welding of pipe or rectangular framed sections using the vertical down technique to minimise distortion and the risk of burn through.
Approvals: American Bureau of Shipping Lloyds Register of Shipping Det Norske Veritas
Recommended Amperages Dia. Length mm mm 2.0 305 2.5 305 3.2 380 4.0 380 5.0 455 AC 45V DC + or -
Red 4112
Welding Positions: F, H, V, VD, OH
Amperes
Typical Mechanical Properties of Weld Metal Tensile Strength 480 MPa Yield Value 447 MPa Elongation(1 = 5d) 31% Impact Value Charpy 108J Average V Notch at 0oC
40-60 60-85 90-130 130-180 180-230
Typical Chemical Analysis C 0.05% Mn 0.48% Si 0.29% Storage Store electrodes in a dry place. To recondition moist electrodes bake for one hour at 110oC in a vented oven.
30
DESCRIPTION: The WELDWELL PH 45E is a conventional electrode having a very low silicon content. It was specially developed for the welding of low silicon plate, eg "lyco" used in the fabrication of galvanising baths, etc. Welding Techniques: Before welding the current should be checked for the application. If the current is too low the weld bead will be lumpy and irregular. If too high an irregular bead with sharp ripples and excess spatter will be the result. A medium arc length should be made, too short an arc will produce a high crowned bead with little wash in.
Recommended Amperages Dia. mm 4.0 6.0
Length mm 455 455
: :
E6020 E4120-0
WELDWELL
45E ELECTRODES FOR WELDING LOW SILICON PLATE TIP COLOUR FLUX MARKING
Amperes
Green PH 45E 6020 E4120
Welding Positions: F, H, V, OH
140-180 200-280
Typical Chemical Analysis C 0.04% Mn 0.76% Si 0.03%
AC 50V DC Typical Mechanical Properties of Weld Metal Tensile Strength Yield Value Elongation(1 = 5d) Impact Value Charpy V Notch at 0oC
AWS A5.1 AS/NZS 1553.1
507 MPa 439 MPa 24% 73 J
Storage Store electrodes in a dry place. To recondition moist electrodes bake for half an hour at 120oC in a vented oven.
31
DESCRIPTION: ! Heavy rutile coating. ! Metal transfers in fine spray across the arc. ! Touch welding technique. ! Quick flowing characteristics. ! Slag self-detaching. ! Smooth and steady arc. ! Appearance very smooth and flat, with no undercut. ! Welds can be drawn out for long small fillets. ! For use where fine appearance enhances sales appeal of weldments. Applications: For quality welding of mild steel sheet speedily and with very little distortion. Constructional work, also oil and water-tight jobs. Truck and Car Body Industry, Steel Furniture, Agricultural Machinery, Motor Mower Frames, Pressure Tanks, Water or Air, etc. Welding Techniques To gain the optimum results with the WELDWELL PH 46 Electrode a Touch and Draw Technique is advisable, the speed of travel depending upon the weld size desired. For economy and fine finish with some work a large gauge size is used and the weld is "stretched" out at a faster speed of travel. In some cases however, a very short arc can be used.
AWS A5.1 AS/NZS 1553.1
: :
E6012 E4113-0
WELDWELL
46 ELECTRODES FOR WELDING MILD STEEL
TIP COLOUR FLUX MARKING
Orange PH 46 6012 E4113
Approvals: American Bureau of Shipping Lloyds Register of Shipping Bureau Veritas Welding Positions: F, H, V, OH
Due to the very fluid slag, care must be taken to ensure that the work is free of rust, heavy mill scale and paint. The amperages used can be varied quite substantially to suit different working conditions. Due to the low viscosity of the slag, it is not recommended to proceed downwards with the work angle at a greater slope than 20o.
Typical Mechanical Properties of Weld Metal Tensile Strength 477 MPa Yield Value 438 MPa Elongation(1 = 5d) 34% Impact Value Charpy 84 J V Notch at 0oC
Recommended Amperages Dia. Length Amperes mm mm 2.0 305 40-60 2.5 305 60-100 3.2 380 80-140 4.0 380 130-180
Typical Chemical Analysis Deposition Rate kg/hr*
C Mn Si
1.02 1.44
0.04% 0.44% 0.25%
Storage Store electrodes in a dry place. To recondition moist electrodes bake for half an hour at 120oC in a vented oven.
* Deposition rate at maximum amps. AC 50V DC -
32
DESCRIPTION: The WELDWELL PH 48A is a Rutile Electrode. It is for all positional general purpose welding of mild steel. The arc stability on low open circuit voltages makes it excellent for use on 230V single phase welding machines. The slag has quicker freezing properties than many types of similar class electrodes, this makes it suitable for out of position welding and it offers a quite remarkable tolerance to bad fit-up. The easy starting and re-starting properties combined with quiet running make it a good electrode for welding galvanised steel and pipe. Welding Techniques PH 48A is used with either a short free arc or by contact if conditions are suitable. The welding amperage can be varied considerably to gain ease of control when welding thick to thin, etc. When used with DC current it is normally connected to the negative (-) pole. Functions of the Coating of PH 48A The function of the coating is two-fold: 1. To protect the metal across the arc. 2. To protect the deposited metal while it is cooling. When the arc is established, and the melting of the electrode starts, a protruding sheath of flux forms at the electrode tip. The metal globules are transferred across the arc and the coating melts rather more slowly than the metal, thus allowing the coating to form a cup, which shields the weld metal as it is being deposited, exercises a directional control over the arc, and reduces operator fatigue. The combination of the coating produces an inert gaseous shield, or reducing atmosphere, which envelopes the arc and the molten metal. The resultant chemical reactions produce a slag covering which rises over the deposited metal and shields it from the atmosphere during final cooling. This slag cover also has a beneficial annealing or refining influence upon the grain structure of the deposit. This influence is well illustrated by the excellent mechanical properties shown. After the weld has been completed, the removal of the cold slag is practically automatic, and consequently, it is not necessary to waste valuable time by excessive chipping or hammering, as it is in the case with many other types of electrodes. Recommended Amperages Dia. Length Amperes mm mm 2.5 305 70-100 3.2 380 90-135 4.0 380 130-180
Deposition Rate kg/hr* 1.00 1.60
* Deposition rate at maximum amps. AC 45V DC -
33
AWS A5.1 AS/NZS 1553.1
: :
E6013 E4112-0
WELDWELL
48A ELECTRODES FOR WELDING MILD STEEL TIP COLOUR FLUX MARKING
Silver PH 48A 6013 E4112
Approvals: Lloyds Register of Shipping Bureau Veritas Welding Positions: F, H, V, VD, OH Typical Mechanical Properties of Weld Metal Tensile Strength 521 MPa Yield Value 467 MPa Elongation(1 = 5d) 31% Impact Value Charpy 59 J V Notch at 0oC Typical Chemical Analysis C 0.04% Mn 0.50% Si 0.40% Storage Store electrodes in a dry place. To recondition moist electrodes bake for half an hour at 120oC in a vented oven.
DESCRIPTION: The WELDWELL PH 68 is a medium-heavy-coated rutile electrode which produces very rapidly solidifying slag. It is an outstanding electrode for welding in all positions and at places difficult to reach. An important feature is that the same current can be used for welding in any position. This means that welding can be done without repeated setting of the current, and accordingly a considerable saving in time is obtained. PH 68 is suitable for vertical down welding because of the excellent slag control. Applications: The PH 68 is suitable for welding in sharply curved and poorly fitting grooves, as well as inclined grooves. It melts off in fairly coarse droplets, for which reason it is used for bridging large gaps. The very rapidly solidifying slag prevents the liquid weld metal from flowing away when welding is done in difficult positions, especially pipe welding. Welding Techniques Before welding commences, the current setting should be checked to see that it is correct for the type of work. If the current is too low, the metal tends to pile and the bead will be lumpy and irregular. If the current is too high, a flat deposit with undue spatter and wastage of the electrode will result. Different applications require variations within the recommended current range and with PH 68 a current setting is possible to allow welding in all positions without having to alter it. In general, a medium arc length is used to gain even welds but touch welding is possible at currents near to maximum. In vertical positions, extremely heavy deposits of mitre contour can be made in one pass for butt and fillet welds using a triangular weaving motion. For second and subsequent passes, only a simple side to side weave is required with a slight pause in each corner to avoid undercutting. When used with DC it is normally connected to the negative (-) pole. Recommended Amperages Dia. Length Amperes mm mm 2.5 305 60-95 3.2 380 70-125 4.0 380 130-170 5.0 455 170-240
Deposition Rate kg/hr* 1.20 1.68 2.22
* Deposition rate at maximum amps. AC 50V DC The type PH 68 is highly recommended to weld Galvanised Steel.
34
AWS A5.1 AS/NZS 1553.1
: :
E6013 E4112-A
WELDWELL
68 ELECTRODES FOR WELDING MILD STEEL TIP COLOUR FLUX MARKING
Red PH 68 6013 E4112
Approvals: American Bureau of Shipping Lloyds Register of Shipping Bureau Veritas Welding Positions: F, H, V, VD, OH Typical Mechanical Properties of Weld Metal Tensile Strength Yield Value Elongation(1 = 5d) Impact Value Charpy V Notch at 20oC
495 MPa 443 MPa 29% 87 J
Typical Chemical Analysis C 0.06% Mn 0.43% Si 0.46% Storage Store electrodes in a dry place. To recondition moist electrodes bake for half an hour at 120oC in a vented oven.
DESCRIPTION: The WELDWELL PH 78 electrode deposits weld metal which combines the advantages of both a rutile and a basic electrode. PH 78 has a medium-heavy rutile coat which yields a fairly thin fluid type of slag and a rather strong protective gas stream. It is suitable for welding in all positions except vertical down and due to its remarkable arc action it is excellent for welding pipes. This electrode is tested for impact values at minus 20oC, the deposited weld metal will therefore be very suitable for welding pipe which operates at low temperatures. When welding vertically-up a relatively high current is required for ease of welding resulting in a high deposition rate. Due to its nature, the slag is insensitive to heat accumulation in the workplace, which contributes towards obtaining welds of good X-ray quality. Applications: General purpose mild steel welding. Pipe welding, especially on site. Pressure vessels, ship construction, tanks and body construction or repairs. Welding Techniques For downhand welding the arc should be kept short. In upward welding a medium arc length is recommended, and if beads are deposited with weaving, the weaving movement should be carried out rather quickly. Recommended Amperages Dia. Length Amperes mm mm 2.5 305 60-95 3.2 380 90-140 4.0 380 120-190
Deposition Rate kg/hr * 0.78 1.15 1.75
AWS A5.1 AS/NZS 1553.1
: :
E6013 E4113-2
WELDWELL
78 ELECTRODES FOR WELDING MILD STEEL TIP COLOUR FLUX MARKING
Violet PH 78 6013E 4113
Approvals: American Bureau of Shipping Bureau Veritas Welding Positions: F, H, V, OH Typical Mechanical Properties of Weld Metal Tensile Strength 508 MPa Yield Value 455 MPa Elongation(1 = 5d) 27% Impact Value Charpy 83 J V Notch at -20oC Storage Store electrodes in a dry place. To recondition moist electrodes bake for half an hour at 120oC in a vented oven.
* Deposition rate at maximum amps. AC 50V DC Typical Chemical Analysis C 0.05% Mn 0.69% Si 0.12%
35
DESCRIPTION: The WELDWELL PH C18 is a heavy coated rutile electrode with a relatively large amount of iron powder in the coating, thus permitting a larger amount of metal to be deposited very easily. This type is suitable for welding in ALL positions with particularly striking results in vertical down welding. The PH C18 has deep-penetrating properties and thanks to the protective effect of the deep cup, the weld metal is very pure. The slag is easy to remove. Applications: This type owes most of its field of application to the positive root penetration in vertical down welding. Especially in shipbuilding much use is made of this property. In a great deal of work with vertical fillet welds the root run is deposited with PH C18 electrodes, followed by a second and a third, if necessary. When large fillets are required it is good practice to use PH C18 for root runs, then use the vertical up method with PH 48A to complete. Amongst the many attributes of PH C18 is its ability to be used as a cutting or gouging electrode. PH C18 is an excellent means of making very strong Spot Welds in thin plate. The maximum thickness of the upper plate must not exceed 3 mm. There is, of course, no limit to the thickness of the base plate. Welding Techniques For vertical down welding the electrode is held at an angle of about 75o to the direction of travel. When metal plate under 4 mm is welded in this manner the angle of the electrode is adjusted to about 35o and the speed of travel increased. The touch technique must be used. When welding the heavier plate at a 75o angle the formation of a tiny drop of molten iron and slag regularly appears just below the tip of the electrode. This drop is periodically blown away and should instantly reappear, since it is proof of root penetration which is only acquired when the electrode is being held at the correct angle of 75o. Should this phenomenon not appear, eg when welding at an angle of say 60o, slag will be included right in the corner, resulting in lack of root penetration. The function of PH C18 electrodes is influenced unfavourably by rusty, scaly or dirty plate because of the fact that these impurities increase the fluidity of the slag. When metal has to be removed, ie tack welds, fillet welds or to vee out a crack, the PH C18 is excellent.
Recommended Amperages Dia. Length Amperes mm mm 2.5 305 80-120 3.2 380 130-160 4.0 380 150-210 5.0 450 210-300 * Deposition rate at maximum Amps. AC 50V DC + Cutting AC 50V or DC -
Deposition Rate kg/hr * 1.55 2.22 3.60
36
AWS A5.1 AS/NZS 1553.1
: :
E7014 E4814-0
WELDWELL
C18 ELECTRODES FOR WELDING MILD STEEL TIP COLOUR FLUX MARKING
Green PH C18 7014 E4814
Approvals: American Bureau of Shipping Lloyds Register of Shipping Bureau Veritas Welding Positions: F, H, V, VD, OH Typical Mechanical Properties of Weld Metal Tensile Strength 494 MPa Yield Value 446 MPa Elongation(1 = 5d) 30% Impact Value Charpy 66 J V Notch at 0oC Typical Chemical Analysis C 0.075% Mn 0.56% Si 0.40% Storage Store electrodes in a dry place. To recondition moist electrodes bake for half an hour at 120oC in a vented oven.
DESCRIPTION: The WELDWELL PH 22 is a heavy coated, rutile electrode, with a large amount of iron powder in the flux coating. It is used for high speed contact welding of mild steel in the flat and horizontal positions.
AWS A5.1 AS/NZS 1553.1
The weld appearance is smooth and flat with very good edge tie-in, without undercut. Because of the high iron powder content of the flux the deposition rate is very high with a weld metal efficiency of 140-160%.
E7024 E4824-0
WELDWELL
22
Welding can be carried out using AC power sources with a minimum of 50 open circuit volts, or DC power sources with electrode positive + or negative - (- preferred). The PH 22 electrode features excellent re-strike ability, very good slag and weld pool control and slag detaches very easily.
: :
IRON POWDER ELECTRODES FOR WELDING MILD STEEL TIP COLOUR FLUX MARKING
Orange PH 22 7024 E4824
Approvals: Lloyds Register of Shipping Bureau Veritas
Applications: Roof trusses, ship building, buckets, dozers, rolling stock, bridge girders, tank ends, beams, heavy machinery frames.
Welding Positions: F, H
Welding Techniques A touch weld technique is recommended, where the flux at the end of the electrode is lightly touching the workpiece. The electrode should be angled in the direction of travel, 45o to 65o, so as to prevent the slag touching the electrode tip.
Typical Mechanical Properties of Weld Metal Tensile Strength 502 MPa Yield Value 453 MPa Elongation(1 = 5d) 30% Impact Value Charpy 63 J V Notch at 0oC Typical Chemical Analysis C 0.05% Mn 0.90% Si 0.25%
Recommended Amperages Dia. Length Amperes mm mm 3.2 380 130-170 4.0 455 185-220 AC 50V
Storage Store electrodes in a dry place. To recondition moist electrodes bake for half an hour at 250oC in a vented oven.
DC + or - (- preferred)
37
DESCRIPTION: The WELDWELL PH 7024 is a heavy coated rutile contact type electrode developed for high speed welding of mild steel in the downhand and horizontal positions using AC or DC current. The high iron powder content in the flux coating gives high efficiency combined with excellent mechanical properties and weldability.
: :
E7024 E4824-0
WELDWELL
7024
PH 7024 Features ! Highest Deposition Rates ! Ease of Welding ! Excellent Appearance at all Speeds ! Extremely Easy Slag Removal ! Virtually No Spatter ! Instant Striking and Re-Striking ! Very Neat Mitre Fillets ! No Undercutting ! Efficiency = 140-160%
IRON POWDER ELECTRODES FOR WELDING MILD STEEL TIP COLOUR FLUX MARKING
Applications: Dozers, Buckets, Ship Building, Roof Trusses, Rolling Stock, Bridge Girders, Crusher Frames, Pressure Vessels, Heavy Machinery Frames, Tank Bottom Welding, Beams and Blades. Welding Techniques A touch weld technique is recommended with the electrode angle adjusted in the direction of travel so as to prevent the slag touching the electrode tip. The electrode should bisect the angle of the joint at approximately 50o-55o for 4.0 mm and 65o for 5.0 mm, other diameters at approximately 45o. Recommended Amperages Dia. Length Amperes mm mm 2.5 305 90-140 3.2 380 130-160 4.0 455 180-210 5.0 455 260-320
AWS A5.1 AS/NZS 1553.1
Deposition Rate kg/hr *
White PH 7024 E4824
Approvals: American Bureau of Shipping Lloyds Register of Shipping Bureau Veritas Welding Positions: F, H Typical Mechanical Properties of Weld Metal
Tensile Strength Yield Value Elongation(1 = 5d) Impact Value Charpy V Notch at 0oC
507 MPa 447 MPa 31% 71 J
Typical Chemical Analysis C 0.05% Mn 0.59% Si 0.36%
1.9 3.00 5.05
Storage Store electrodes in a dry place. To recondition moist electrodes bake for half an hour at 250oC in a vented oven.
* Deposition rate at maximum Amps. AC 50V DC -
38
DESCRIPTION: The WELDWELL PH 31A is a thinly coated electrode of the cellulose type, intended for welding in all-positions. The excellent properties of this type show to the best advantage in downward welding, in particular the stove-pipe technique. The arc is easy to ignite, is powerful and extremely stable, giving this electrode deep-penetration properties. The thin layer of slag being easy to remove. The PH 31A type of electrode has been primarily developed for welding circumferential seams in pipe lines in the vertical down position; the welding time is considerably shorter than where upward welding is done conventionally. Welding Techniques Circumferential pipe seams to be welded with the PH 31A type must have an included angle of 60o and a root face of 1.5mm. The root gap between pipes must be 1.5mm wide. The root pass (or stringer bead) is done by pushing the electrode firmly into the root of the weld, so that the arc burns inside the pipe, and is carried out with a relatively high rate of travel. As the coating is fairly tough, no drawbacks will be encountered should the electrode become slightly bent by this firm pressure. The root pass is ground flat, to prevent slag inclusions when the second layer is welded. The second layer (hot-pass) is welded with a high current, a short to medium arc length and a fairly high travel speed. The subsequent layers are welded with a medium arc length. Sometimes a rapid thrusting movement is used to advantage. To prevent porosity relatively thin layers are welded. As desired, a slightly weaving motion can be employed or layers can be deposited side by side. The X-ray quality of the joints welded as described satisfy the requirements to which they have to conform in practice. The PH 31A electrode can be used either with DC + or with AC where the open circuit voltage is not less than 70V. Recommended Amperages Dia. Length Amperes Fusion Time mm mm in seconds 2.5 305 60-95 3.2 380 90-125 52 4.0 380 115-175 65 5.0 380 160-220 79 Note that fusion time rate are at maximum current values. AC 70V DC +
39
AWS A5.1 AS/NZS 1553.1
: :
E6011 E4111-3
WELDWELL
31A ELECTRODES FOR WELDING MILD STEEL
TIP COLOUR FLUX MARKING
Brown PH 31A 6011 E4111
Approvals: American Bureau of Shipping Lloyds Register of Shipping Bureau Veritas
Welding Positions: F, H, V, VD, OH Typical Mechanical Properties of Weld Metal Tensile Strength Yield Value Elongation(1 = 5d) Impact Value Charpy V Notch at -30oC
510 MPa 410 MPa 31% 89 J
Typical Chemical Analysis C 0.12% Mn 0.60% Si 0.16% Storage Store electrodes in a dry place. Rebaking is not recommended.
DESCRIPTION: Pipemaster 60 is a quick starting, cellulosic mild steel electrode that provides outstanding arc stability, penetration and wash-in. Ideal for welding in all positions and produces x-ray quality welds with a light slag that is easy to remove. Pipemaster 60 can be used to weld the following API 5L steels: Grade A, B, X-42, X-46, X-52, X-56 and for the root pass on material up to X-80. Applications: Pipes, plates, construction, shipbuilding and general purpose fabrication and maintenance welding. Features: ! Quick starting efficiency ! All Position ! Excellent vertical down ! Excellent arc stability ! Excellent penetration ! Light slag
: :
E6010 E4110-3
HOBART
ELECTRODES FOR WELDING MILD STEEL TIP COLOUR FLUX MARKING
None
Approvals: Lloyds Register of Shipping American Bureau of Shipping
Welding Techniques: Arc length 3 - 6 mm. For welding in the flat position stay ahead of the puddle and use a slight whipping motion. For vertical up and overhead, use a slight whipping or weaving technique. When welding vertical down use higher amps and a faster travel speed, staying ahead of puddle. Vertical down welding is commonly used when welding pipe. Recommended Amperages Dia. Length Amperes mm mm 2.4 355 40-70 3.2 355 65-130 4.0 355 90-175 4.8 355 140-225
AWS A5.1 AS/NZS 1553.1
Optimum Amperes 50 100 140 170
Deposition Rate kg/hr * 0.59 0.73 0.86 1.18
* At optimum amperes DC +
40
Welding Positions: F, H, V, VD, OH Typical Mechanical Properties of Weld Metal Tensile Strength 511 MPa Yield Value 436 MPa Elongation(1 = 5d) 26% Impact Value Charpy 76 J V Notch at -30oC Typical Chemical Analysis C 0.06% Si 0.20% Mn 0.40% Storage Store electrodes in a dry place. Rebaking is not recommended.
DESCRIPTION: Pipemaster 70 is an excellent, all position, cellulosic mild steel electrode that provides strong, dependable, x-ray quality welds. It delivers the arc stability and arc force you need for the best penetration. It is ideal for vertical-down welding, single or multipass on 5L, 5LX and X52 through X65 pipe.
AWS A5.5 AS/NZS 1553.2
: :
E7010-P1 E4810-P1
HOBART
Applications: High yield pipe steels, drill platforms, shipbuilding, storage tanks. ELECTRODES FOR WELDING MILD STEEL
Features: ! Quick starting efficiency ! All Position ! Excellent vertical down ! Excellent arc stability ! Excellent penetration and wash-in ! Light slag
TIP COLOUR FLUX MARKING
Welding Techniques: Arc length 3 - 6 mm. For welding in the flat position stay ahead of the puddle and use a slight whipping motion. For vertical up and overhead, use a slight whipping or weaving technique. When welding vertical down on pipes etc, use higher amps and a faster travel speed, staying ahead of the arc. Recommended Amperages Dia. Length Amperes mm mm 3.2 355 70-140 4.0 355 80-190 4.8 355 120-230
Optimum Amperes 100 160 190
Deposition Rate kg/hr * 0.99 1.22 1.75
* At optimum amperes DC +
None
Approvals: Lloyds Register of Shipping American Bureau of Shipping Welding Positions: F, H, V, VD, OH Typical Mechanical Properties of Weld Metal Tensile Strength 625 MPa Yield Value 514 MPa Elongation(1 = 5d) 25% Impact Value Charpy 60 J V Notch at -30oC Typical Chemical Analysis C 0.10% Si 0.40% S 0.01% Mo 0.10%
Mn P Ni Cr
0.85% 0.01% 0.55% 0.02%
Storage Store electrodes in a dry place. Rebaking is not recommended.
41
WELDWELL WELDING ELECTRODES BASIC COATED ELECTRODES FOR WELDING MILD AND MEDIUM TENSILE STEELS Since their introduction basic-coated electrodes, also called low-hydrogen electrodes, have been employed mainly where quality requirements are laid down which cannot be realised or are difficult to meet with other types. The deposited metal has a high resistance to hot and cold cracking, a high notch toughness and an excellent X-ray quality even if impurities such as sulphur are present in the material to be welded. On account of the low hydrogen content of the weld metal the risk of cracking of the weld and the heat-affected zone is extremely limited. Accordingly these electrodes are particularly suitable for the welding of heavy workpieces and of very rigid mild steel constructions. They are also recommended for welding low-alloy steel and steel of which the carbon and sulphur contents are higher than those of readily weldable mild steel.
BASIC-COATED ELECTRODES FOR ALL-POSITION WELDING
Owing to the high solidification rate of the weldpool, which permits high currents for welding in difficult positions, the low-hydrogen electrode is the fastest type for those positions. On the other hand, because of its nature, the slag will not be entrapped easily. These properties, together with a good 'penetrating arc', explain the welder's liking for this electrode. Since the optimum properties for each of the wide variety of welding-applications cannot be had in one electrode, a number of different unalloyed basic-coated Weldwell electrodes are available. The differences between these types may relate to welding-properties, deposition rate, mechanical values, kind of current, etc. Refer to the information on each electrode to find the most suitable for any particular job. WELDWELL PH 27 has a coating which emits a forceful arc with a slag which sets quickly, resulting in a useful type for vertical down welding. WELDWELL PH 27P the P denotes "pipe" this type especially designed for pipe welding, particularly welding downwards and has excellent properties for bridging gaps and making tie-ins where the pipes are misaligned. WELDWELL PH 56S These thinly-coated types of 100% efficiency produce welds in all positions with very high impact properties. WELDWELL PH 56R - A specially designed low hydrogen electrode for rapid joining of steel with large cross sections, using the enclosed welding process. AUSTARC 16TC is an easy to use dual coated electrode for welding in all positions with DC or AC power sources with open circuit voltages as low as 45 OCV. The weld pool is very controllable. Re-strike and slag release are very good. WELDWELL PH 75 is designed to produce welds where high impact values are required at sub-zero temperatures and for welding in all-positions. WELDWELL PH 77 produces good efficiency, it has a very quiet arc with low spatter levels and gives excellent results in all-positions with high impact values at -50oC. WELDWELL PH 118. This type is designed to produce very strong welds in low alloy-high tensile steels and with excellent impact values at low temperatures, WELDWELL PH KV3 for low alloy and medium tensile steels, especially suitable for high quality pipe welds in all positions and Cr/Mo high temperature applications.
FOR DOWNHAND WELDING
WELDWELL PH C6H has a very heavy coating containing zirconium oxide which gives welds of up to 200% efficiency and with very good mechanical properties.
42
DESCRIPTION: All gauges of this basic-coated electrode are extremely suitable for welding in the Vertical-Down position. The instructions covering welding with low-hydrogen electrodes and their storage should be followed. The weldments have a flat profile and are highly insensitive to cracking. Where the WELDWELL PH 27 is employed correctly, the weld metal has a finely ribbed appearance and an excellent wetting action, which eliminates undercut. In most cases, the slag is selflifting, but in all cases there is a minimum of post weld cleaning up. With the aid of the PH 27 gaps can be readily bridged in verticaldown welding. In addition, the diameters 3.2 mm and 4.0 mm are very suitable for welding root passes of single and double-vee joints in this position. As this electrode tolerates very high currents the PH 27 yields a con-siderable economic advantage in comparison with conventional low-hydrogen electrodes which have to be welded vertically upwards with a relatively low current. The high welding speeds which can be obtained, as compared with vertical-up welding, result in substantially less distortion. The PH 27 can be consumed either on AC or with the electrode connected to the positive pole, on DC. Welding Techniques How to Weld Vertically Downwards with the Weldwell PH 27. Like all Low-Hydrogen types, the PH 27 may be used with a short arc. Too long an arc will cause porosity. Use of Touch-Welding technique is not recommended, since this adversely affects root penetration, and the welding action. Welding is done with maximum current, in order that the greatest possible benefit may be derived from the use of the PH 27. The electrode is held at an angle of 80o to 90o to the direction of travel. In ship building vertical fillet joints are often limited by horizontal plates, causing a change of electrode angle to approximately 110o in the last part of the joint. Experience has proved that the slag is still easy to control above the arc, and in these circumstances the weld appearance is entirely accept-able. Making bead junctions likewise presents no problems at all. Before the arc is extinguished, the electrode is removed from the crater in the upward direction. Then the next rod is started a little below the crater, after which the latter is filled up and vertical-down welding continues. The PH 27 can be used for vertical-down welding of fillet joints in multiple layers. Overlapping runs are made if more than two layers are deposited. Should two layers be sufficient, then the second layer is welded with a slightly faster weaving motion whilst the arc is kept short. As already stated, bridging of gaps presents no problems at all in vertical-down welding. Recommended Amperages Dia. Length Amperes mm mm 3.2 305 150 max 4.0 380 200 max 5.0 455 270 max * Deposition rate at maximum Amps. AC 70V DC +
AWS A5.1 AS/NZS 1553.1
: :
E7048 H4 E4848-3 H5
WELDWELL
27 LOW HYDROGEN ELECTRODES FOR WELDING MILD AND MEDIUMTENSILE STEELS TIP COLOUR FLUX MARKING
White PH 27 7048 E4848
Approvals: American Bureau of Shipping Lloyds Register of Shipping Bureau Veritas Welding Positions: F, H, VD, OH Typical Mechanical Properties of Weld Metal Tensile Strength 507 MPa Yield Value 439 MPa Elongation(1 = 5d) 32% Impact Value Charpy 183 J V Notch at -30oC Typical Chemical Analysis C 0.04% Mn 1.15% Si 0.45% Storage (See also page 88.) Once the packet has been opened, these electrodes should be stored in a heated cabinet at a temperature of 20oC minimum and/or at least 10oC above ambient. Good ventilation should be allowed. For highest weld quality, these electrodes should be baked before use at 280oC for one hour to achieve a maximum weldmetal hydrogen level of 10ml/100g.
Deposition Rate kg/hr * 1.3 1.8 2.53
Do not redry more than three times. These temperatures should also be used to recondition damp electrodes. Use from a hot box during welding.
43
DESCRIPTION: The basic coated WELDWELL PH 27P electrode has been specially developed for welding circumferential joints using the vertical down technique ("stove-pipe welding"). It provides the answer to the ever increasing requirements for strength and toughness in pipe welds. The low-hydrogen content of the PH 27P electrode deposit reduces the risk of hydrogen heataffected zone and weld metal cracking; such defects are more likely to occur with increasing pipe steel strengths. In particular, its basic high purity weld metal ensures high impact toughness, along with other improvements over cellulosic electrodes. Excellent Operational Characteristics PH 27P electrode has a stable smooth arc, low spatter volume, and very good slag control; easy deslagging properties minimise clean up time. High productivity results from high current intensities used with this electrode and the increased recovery rate (120% approx.)
AWS A5.5 AS/NZS 1553.2
: :
E8018-G H8 E5548-G H5
WELDWELL
27P LOW HYDROGEN ELECTRODES FOR WELDING MILD AND MEDIUMTENSILE STEELS TIP COLOUR FLUX MARKING
Violet PH 27P 8018-G E5548-G
Applications: Applications of the PH 27P electrode are principally oil and gas pipelines requiring welds of high strength and ductility, as in the North Sea and Arctic areas. The high deposition rate makes it a very attractive alternative for the low-hydrogen electrodes which are presently employed uphill for valve connections, tie-ins and main crossing welds.
Approvals: American Bureau of Shipping Lloyds Register of Shipping Bureau Veritas
Process pipe work is another area where time savings of 30 to 50% are achieved. Pipe diameters which can be satisfactorily welded with the PH 27P electrode are from 200 mm upwards. The minimum wall thickness is 6 mm.
Recommended Amperages Dia. Length Amperes mm mm 2.5 355 80-100 3.2 355 130-150 4.0 355 180-210 DC +
Welding Techniques Being an electrode for pipe welding, a branch of welding requiring a high degree of skill, welders must necessarily become familiar with the welding technique developed for the PH 27P. Experience indicates that this can be achieved quicker and with higher success rate, compared with training welders to use cellulose electrodes on pipe welding. Welders trained in downhill welding with cellulose types on pipes are favoured over others, since they are already used to high travel speeds and continuous change of welding position with consequent adaption of the rod to this. However, due to their training with cellulosic electrodes, welders generally have to be alerted to the following differences. *
Starting porosity results from drawing a long arc after striking. The PH 27P arc should be kept short at all times.
*
Usually cellulosic electrodes are kept under a rather sharp angle with the direction of travel, resulting in long arc lengths. The PH 27P is held almost perpendicular to the pipe.
*
A welder can be misled by the considerably lower amount of spatter from the PH 27P, so giving the impression that current intensity is too low. Raising this to gain "the required level of spatter" adversely affects slag and weld pool behaviour and promotes porosity.
*
WELDWELL PH 27P slag stays at a greater distance from the arc than a cellulosic slag. The welder should avoid slowing down travel speed as a reaction to this, otherwise the slag will run through the arc or the weld pool will be overheated.
44
Welding Positions: F, H, VD, OH
Typical Mechanical Properties of Weld Metal Tensile Strength 594 MPa Yield Value 561 MPa Elongation(1 = 5d) 27% Impact Value Charpy 151 J V Notch at -20oC Typical Chemical Analysis C 0.05% Mn 1.15% Si 0.45%
Storage (See also page 88.) Once the packet has been opened, these electrodes should be stored in a heated cabinet at a temperature of 20oC minimum and/or at least 10oC above ambient. Good ventilation should be allowed. For highest weld quality, these electrodes should be baked before use at 280oC for one hour to achieve a maximum weldmetal hydrogen level of 5ml/100g. Do not redry more than five times. These temperatures should also be used to recondition damp electrodes. Use from a hot box during welding.
DESCRIPTION: Austarc 16TC is a smooth running, basic flux low hydrogen electrode, developed for all positional (except vertical down) welding, using AC or DC power sources. The electrode gives exceptional stability and weldability for its class, and produces high quality weld deposits with reliable notch toughness to -40oC. Austarc 16TC is manufactured using a unique twin coating extrusion process, which produces electrodes with two concentric flux coatings. Arc stabilising elements are concentrated in the inner coating of the electrode for significantly improved arc stability on low open circuit AC welding machines. Applications: Austarc 16TC is the ideal low hydrogen electrode for welding carbon, carbon-manganese and low alloy high strength steels used in a multitude of critical and non-critical applications. This electrode is particularly suitable for welding heavy wall joints subject to high degrees of restraint and for structural applications where notch toughness down to -40oC is a prerequisite. Austarc 16TC is often used in maintenance situations as a buffer or build-up layer on agricultural and earth moving equipment prior to hard surfacing. Welding Techniques Arc striking and re-striking is easily accomplished. Use a light dragging action on the rod end to achieve ignition. Welding is carried out with a short arc and low travel speeds. Recommended Amperages Dia. Length Amperes mm mm 2.5 305 60-90 3.2 380 90-135 4.0 380 140-190 5.0 455 190-240 6.0 455 250-310 AC 45 OCV for 2.5 and 3.2 mm AC 55 OCV for 4.0, 5.0 and 6.0 mm DC +
AWS A5.1 AS/NZS 1553.1
: :
E7016 H8 E4816-4H10
WIA AUSTARC 16TC LOW HYDROGEN ELECTRODES FOR WELDING MILD AND MEDIUM TENSILE STEELS
TIP COLOUR FLUX MARKING
Bronze 4816
Approvals: Lloyds Register of Shipping American Bureau of Shipping Det Norske Veritas Welding Positions: F, H, V, OH Typical Chemical Analysis C 0.05% Mn 1.18% Si 0.52% Storage (see also page 88.) Once the packet has been opened, these electrodes should be stored in a heated cabinet at a temperature of 20oC minimum and/or at least 10oC above ambient. Good ventilation should be allowed. For highest weld quality, these electrodes should be baked before use at 300oC for two hours to achieve a maximum weld metal hydrogen level of 10ml/100g.
Typical Mechanical Properties of Weld Metal Tensile Strength 518 MPa Yield Value 426 MPa Elongation 33% Impact Value Charpy V Notch at 118J -40oC Average
Do not re-dry more than five times. These temperatures should also be used to recondition damp electrodes. Use from a hot box during welding.
45
DESCRIPTION: The WELDWELL PH 56S is a basic coated C/Mn electrode providing excellent mechanical properties. Due to the thin coating and concentrated arc this electrode ensures fully penetrated root passes even under adverse conditions, such as small gaps and narrow joints. The strong protective gas stream is a further advantage. Low moisture content of the coating and high resistance to moisture re-absorption is a major benefit long recognised by the offshore and general structural steel industries, where avoidance of hydrogen induced cracking is of crucial importance. Applications: PH 56S is widely adopted for offshore fabrication to ensure consistent results, with the assurance of high impact values in the as-welded condition and further improved by stress relieving. COD testing confirms excellent fracture toughness after stress relieving. Many years of successful use in offshore work provides an immense range of approved procedures; also a workforce fully familiar with the PH 56S and well able to exploit the full potential of this electrode for nodes and other primary structural joints. Pipework PH 56S assures the full penetration demanded by the oil and gas industry for offshore and onshore process piping. Welders prefer the better manipulation of this thin coated electrode for handling root passes, particularly when variations in gap width occur due to field fit-up conditions. Root layers for submerged arc filling is another major application area of PH 56S, confirmed by well established procedures in offshore yards. Combinations with other Weldwell "offshore" electrodes. PH 56S can be used advantageously with the following, for joints of primary structural importance. ! As root pass electrode followed by filling with Weldwell PH 77 (E7018-1) for extra productivity due to the 120% recovery of the latter. Most yards tend to avoid use of two electrodes due to the extra supervision involved, but the practice remains sound and is often adopted for tank welding and other general structural work. ! For even more demanding requirements down to -60oC, the Weldwell PH 75 should substitute the Weldwell PH 56S. For further information see Weldwell PH 75 data sheet. General steel structure. PH 56S is widely adopted where assurance of high as-welded impact values are necessary for allposition welds. Electrode performance. PH 56S gives 100% recovery, it can be used equally well for AC or DC + operation; DC - is often preferred for root passes. The electrode is easily welded in thin layers, to gain maximum grain refining from the heat of subsequent runs, and so obtain high toughness properties. X-ray properties of the weld metal are highly regarded by inspectors working to stringent requirements. Welding Techniques It is important that this electrode is welded with a short arc under all conditions. The rate of travel must be slow; weaving, if carried out, must also be slow using no greater movement than three electrode widths each way. To avoid start porosity, strike each fresh electrode on the crater of the preceding run while it is still hot, or by restarting half inch back on previous run and chipping off the thin bead formed there. Recommended Amperages Dia. mm 2.5 3.2 4.0 5.0 6.0
Length mm 305 380 380 455 455
Amperes
Deposition Rate kg/hr *
60-100 85-140 100-180 180-230 230-300
1.14 1.62 2.52 3.36
: :
E7016-H8 E4816-4H5
WELDWELL
LOW HYDROGEN ELECTRODES FOR WELDING MILD AND MEDIUM TENSILE STEELS TIP COLOUR FLUX MARKING
Red PH 56S 7016 E4816
Approvals: Lloyds Register of Shipping American Bureau of Shipping Bureau Veritas Welding Positions: F, H, V, OH Typical Chemical Analysis C 0.05% Mn 1.11% Si 0.34% Moisture reabsorbsion characteristics of Weldwell 56S.
Storage (see also page 88.) Once the packet has been opened, these electrodes should be stored in a heated cabinet at a temperature of 20oC minimum and/or at least 10oC above ambient. Good ventilation should be allowed. For highest weld quality, these electrodes should be baked before use at 350 o C for 1 hour to achieve a maximum weld metal hydrogen level of 10ml/100g or 400 o C for 1 hour to achieve maximum weld metal hydrogen of 5ml/100g. Do not re-dry more than five times. These temperatures should also be used to recondition damp electrodes. Use from a hot box during welding. Typical COD test results Type of joint and Parameters material thickness Position: Preheat temp: Interpass temp: Electrode size:
: 3G 100oC max 140o C 2.5 mm 3.2 mm 4.0 mm Heat treatment: 3h, 580-620oC Steel quality: 50D
* Deposition rate at maximum Amps. AC 7O OCV DC+ or DC- for root passes if preferred Typical Mechanical Properties of Weld Metal Tensile Strength Yield Value Elongation(1 = 5d) Impact Value Charpy V Notch at -40oC Average
AWS A5.1 AS/NZS 1553.1
589 MPa 497 MPa 28% 107 J
46
DESCRIPTION: The WELDWELL PH 56R is a low hydrogen electrode, specially designed for rapid joining of profiles with large cross sections, according to the enclosed-welding process. Being of the low hydrogen type the Weldwell PH 56R yields excellent mechanical properties; it produces a sound X-ray quality and is very insensitive to impurities of the base metal. The use of this electrode in combination with the enclosedwelding process has some striking advantages, which, in short, are: C a considerable saving of time in relation to orthodox methods used for the same applications; C more irregularly shaped profiles can be welded as well, and, because of the great heat input in the seam, it is possible to weld steels with a relatively high carbon content (up to approximately 0.60-0.65% C).
Applications: The enclosed-welding process is employed for making butt welds in round and square bars, heavy flanges, thick plates, rails, rail crossings, rudder shafts, anchor chains, etc.
Welding Techniques Profiles to be joined are sawn or cut off straight and placed 15 to 18 mm apart. Next the gap is enclosed in copper moulds and filled up with the Weldwell PH 56R. The weld is deposited at a high current in one layer, without the need for intermediate chipping. Welding must be done with a very short arc. A detailed brochure on the enclosed-welding process is available.
Recommended Amperage Dia. mm pcs
Length Amperes mm
Fusion Dep rate time g/min kg/hr
5.0
450
sec 76
AC 70 OCV
280
48
2.90
Net weight per 1,000 kg 90.8
DC +
Typical Mechanical Properties of Weld Metal Tensile Strength 530-590 MPa Yield Value 470-510 MPa Elongation(1 = 5d) 26-30% 47-78 J Impact Value Charpy V Notch at -20oC
47
AWS A5.1 AS 1553.1
: :
E7016 E4816
WELDWELL
56R LOW HYDROGEN ELECTRODES FOR WELDING MILD AND MEDIUM TENSILE STEELS
TIP COLOUR None FLUX MARKING PH 56R
Welding Position: F
Typical Chemical Analysis C 0.064% Mn 1.04% Si 0.66% Storage (See also page 88.) Once the packet has been opened, these electrodes should be stored in a heated cabinet at a temperature of 20oC minimum and/or at least 10oC above ambient. Good ventilation should be allowed. For highest weld quality, these electrodes should be baked before use at 350oC for one hour to achieve a maximum weld metal hydrogen level of 10ml/100g or 400oC for one hour to achieve maximum weld metal hydrogen of 5ml/100g. Do not re-dry more than three times. These temperatures should also be used to recondition damp electrodes. Use from a hot box during welding.
DESCRIPTION: The WELDWELL PH 75 is a low hydrogen all position electrode depositing a nickel-alloyed weld metal. The result of this nickel addition is very high impact values are obtained at sub-zero temperatures. These properties are gained regardless of whether the welding is done downhand or vertical up, etc. The PH 75 exhibits very good weldability on both AC and DC and gives excellent results in the welding of root runs of pipes and plates in difficult welding positions. PH 75 is ideal for welding the fine-grains steels of the 1.5% Ni steel and 3.5% Ni steel. Applications: Pipes, vessels, containers, etc, which are designed for low-temperature service. Welding Techniques As for all low-hydrogen electrodes welding must be done with a short arc and at a low rate of travel, should weaving be necessary, this must likewise be carried out slowly. Welding Positions: F, H, V, OH
: :
E7016-C1L H8 E4816-C1L H10
WELDWELL
75 LOW HYDROGEN ELECTRODES FOR WELDING LOW TEMPERATURE STEELS TIP COLOUR Aluminium FLUX MARKING PH 75 7016-C1L E4816-C1L Approvals: American Bureau of Shipping Lloyds Register of Shipping Bureau Veritas Typical Chemical Analysis C 0.04% Mn 0.49% Si 0.40% Ni 2.50%
Recommended Amperages Dia. Length Amperes mm mm 3.2 380 85-140 4.0 380 120-180 AC 70V
AWS A5.5 AS/NZS 1553.2
DC +
Typical Mechanical Properties of Weld Metal Tensile Strength 514 MPa Yield Value 439 MPa Elongation(1 = 5d) 32% 79 J Impact Value Charpy V Notch at -60oC
48
Storage (See also page 88.) Once the packet has been opened, these electrodes should be stored in a heated cabinet at a temperature of 20oC minimum and/or at least 10oC above ambient. Good ventilation should be allowed. For highest weld quality, these electrodes should be baked before use at 350oC for 1 hour to achieve a maximum weld metal hydrogen level of 10ml/100g or 400oC for 1 hour to achieve maximum weld metal hydrogen of 5ml/100g. Do not re-dry more than five times. These temperatures should also be used to recondition damp electrodes. Use from a hot box during welding.
DESCRIPTION: The WELDWELL PH 77 is a low-hydrogen electrode containing iron-powder in the coating. PH 77 is designed to weld in all positions except vertical down.
AWS A5.1 AS/NZS 1553.1
: :
E7018-1 H8 E4818-5 H5
WELDWELL
The welding arc of PH 77 is very quiet and with very little spatter and the weld metal deposits exceptionally smoothly with excellent wash to the weld sides which practically eliminates undercutting. The slag is easy to control and is easy to remove after welding.
77
Compared to the general types of low-hydrogen electrodes the PH 77 performs nearly like a rutile electrode with lowhydrogen results.
LOW HYDROGEN ELECTRODES FOR WELDING MILD AND MEDIUM TENSILE STEELS
This Weldwell PH 77 electrode is for welding unalloyed, micro-alloyed and low-alloy steels up to medium tensile strength. This electrode is used where the highest standards are required, such as high ductility and X-ray qualities. It is excellent for thick plates and highly restrained work pieces, etc. Due to its Low-Hydrogen properties it is suitable to weld sulphur-alloyed (0.2-0.3% S) steels (free cutting steel) and for steels with increased carbon content. PH 77 may be used for cold or hot welding of cast iron but care should be exercised because of carbon pickup which causes brittleness. It is very suitable for most steel castings. Applications: Penstocks, turbines, Class 1 pressure vessels, heavy girders, tanks, earthmoving plant, repair and maintenance, etc. Welding Techniques Arc striking is easy and re-starting is simple as a slight drag brings arc ignition. Welding is done with a short arc and low travel speeds.
TIP COLOUR FLUX MARKING
Black PH 77 7018 E4818
Approvals: American Bureau of Shipping Lloyds Register of Shipping Bureau Veritas Welding Positions F, H, V, OH Typical Mechanical Properties of Weld Metal Tensile Strength 563 MPa Yield Value 483 MPa Elongation(1 = 5d) 29% Impact Value Charpy 123 J V Notch at -50oC Typical Chemical Analysis C 0.04% Mn 1.47% Si 0.31% Storage (See also page 88.) Once the packet has been opened, these electrodes should be stored in a heated cabinet at a temperature of 20oC minimum and/or at least 10oC above ambient. Good ventilation should be allowed. For highest weld quality, these electrodes should be baked before use at 350oC for one hour to achieve a maximum weld metal hydrogen level of 10ml/100g; or 400oC for one hour to achieve a maximum weldmetal hydrogen of 5 ml/100g. Do not re-dry more than three times. These temperatures should also be used to recondition damp electrodes. Use from a hot box during welding.
Recommended Amperages Dia. Length Amperes mm mm 2.5 305 60-105 3.2 380 90-145 4.0 380 140-200 5.0 455 180-300 AC 70V DC +
49
DESCRIPTION: WELDWELL PH C6H electrodes are intended for welding mild and medium tensile steels and have a Zircon-based Coating in which very large amounts of iron powder are included. The efficiency is approximately 195%.
AWS A5.1 AS/NZS 1553.1
: :
E7028 H4 E4828-2 H5
WELDWELL
The deposited metal has a smooth and flat appearance which favours high fatigue strengths. The weld washes or wets very nicely without undercuts.
C6H
Welds obtained with this type show very good mechanical properties and an excellent X-ray quality. As for all lowhydrogen electrodes the weld metal can be pushed into the form of very thick layers, in which case slag removal nevertheless remains excellent, a characteristic of zirconbased electrodes.
LOW HYDROGEN ELECTRODES FOR WELDING MILD AND MEDIUM TENSILE STEELS
PH C6H is intended for Downhand Welding only. The very heavy coating permits high welding currents, and consequently a particularly high deposition rate is obtained. Therefore this type of electrode is eminently suitable for rapidly filling bevelled butt joints in thick and very thick plates and for making positioned fillet welds as well.
Welding Techniques PH C6H can be used to weld either by contact with the workpiece or by a short free arc. AC or DC may be used, but with DC the electrode should be connected to the positive pole.
Recommended Amperages Dia. Length Amperes mm mm 3.2 380 130-180 4.0 455 200-230 5.0 455 260-340 6.0 455 360-440
TIP COLOUR FLUX MARKING
Blue PH C6H 7028 E4828
Approvals: American Bureau of Shipping Lloyds Register of Shipping Bureau Veritas Welding Positions F, H Typical Mechanical Properties of Weld Metal Tensile Strength 513 MPa Yield Value 424 MPa Elongation(1 = 5d) 34% Impact Value Charpy 108 J V Notch at -20oC Typical Chemical Analysis C 0.02% Mn 1.26% Si 0.62%
Deposition Rate kg/hr* 4.00 6.35 8.90
Storage (See also page 88.) Once the packet has been opened, these electrodes should be stored in a heated cabinet at a temperature of 20oC minimum and/or at least 10oC above ambient. Good ventilation should be allowed. For highest weld quality, these electrodes should be baked before use at 280oC for one hour to achieve a maximum weld metal hydrogen level of 10ml/100g. Do not re-dry more than three times. These temperatures should also be used to recondition damp electrodes. Use from a hot box during welding.
* Deposition Rate at maximum amps. AC 70V DC +
50
DESCRIPTION: Weldwell KV3 is an all position, very low hydrogen electrode for welding a wide range of low alloy and medium tensile steels. Because of the stable arc and smooth weldability, KV3 produces high quality welds, and is very suitable for welding tubes and pipes in fixed positions. The chrome and molybdenum bearing composition of KV3 produces strong, tough weld deposits which are highly resistant to weld metal cracking. Suitable for welding 2.25 Cr, 1 Mo and 0.5 Cr, 0.5 Mo, 0.25 V bearing steels in high temperature applications, and other low alloy, medium tensile steels where matching or improved strength and toughness are desired. Weldwell KV3 is the recommended electrode for welding seismic reinforcing bar - Grade 500E. Welding Techniques Welding must be carried out with a short arc and a slow travel rate. Recommended Amperages Dia. Length mm mm 2.5 350 3.2 350 4.0 350 5.0 455
Amperes 65-95 75-130 115-165 180-240
Welding current DC + only Typical Mechanical Properties of Weld Metal Tensile Strength 726 MPa Yield Value 638 MPa Elongation 25%
51
AWS A5.5 AS/NZS 1553.2
: :
E8015-B3L H4 E5515-B3L H5
WELDWELL
LOW HYDROGEN ELECTRODES FOR WELDING LOW ALLOY AND MEDIUM TENSILE STEELS TIP COLOUR FLUX MARKING
Aluminium PH KV3 8015-B3L
Welding Positions F, H, V, OH Typical Chemical Analysis C 0.05% Mo Mn 0.77% P Si 0.22% S Cr 2.10%
0.95% 0.03% 0.01%
Approvals American Bureau of Shipping Storage (See also page 88.) Once the packet has been opened, these electrodes should be stored in a heated cabinet at a temperature of 20oC and/or at least 10oC above ambient. Good ventilation should be allowed. For highest weld quality, these electrodes should be baked before use at 350oC for one hour to achieve a maximum weld metal hydrogen level of 10 ml/100g or 400oC for one hour just before use for maximum weld metal hydrogen of 5 ml/100g. Do not redry more than three times. These temperatures should also be used to recondition damp electrodes. Use from a hot box during welding.
WELDWELL WELDING ELECTRODES ELECTRODES FOR WELDING HIGH TENSILE STEELS
In the following it is assumed that all structural steels with a minimum yield point of approximately 480 MPa are among the high-tensile steels. Mostly such steel qualities are low alloyed, and as a result of their chemical composition they may be sensitive to hydrogen cracking. Sources which may produce hydrogen, such as dirt, grease, oxide scale, etc, on the plates, must therefore be carefully removed before welding. For the welding of these steel qualities low-hydrogen electrodes such as the type Weldwell PH 118 have to be used. These Weldwell electrodes are supplied in sealed packs, to prevent moisture pick-up during transport and storage. In spite of this precaution, it is recommended to dry the electrodes before use, by following the procedure as detailed in the data sheet. As soon as the electrodes have reached the temperature they may be used. It is advisable for the welder not to take more electrodes with him, in small humidity-safe or heated containers, than are necessary for about two hours of welding. Electrodes which have not been kept in humidity-safe conditions have to be rebaked at 400oC for a maximum of one hour, then they can be stored in an oven at 10oC above ambient. When high strength steels are welded the requirements with respect to design, workmanship and inspection must be more stringent than those for structural carbon steels. A design that has abrupt changes in cross sections in regions of high stress cannot be tolerated. Therefore, butt welds are to be preferred to fillet welds. The butt joints should be welded on both sides, to avoid severe stress-raisers at the root. Moreover such welds can more easily be inspected. Tack welds and the root run should be welded with an electrode type having a lower yield value than that applied for filling the joint. After filling or partial filling of one side of the joint, the reverse side can be welded after chipping or gouging the root run. Grinding is necessary after gouging with carbon electrodes, and at least 1 mm of material should be removed. It is common practice also to weld standing fillet welds with an electrode type having lower yield values than the type used for welding butt joints. In order to ensure adequate notch toughness and strength of the HAZ, the recommendations made by the steel supplier with respect to preheating, interpass temperature and heat input must be strictly adhered to. These recommendations have to be followed during tack welding and welding of the root run, as well.
52
DESCRIPTION: The WELDWELL PH 118 is a low hydrogen electrode used for welding low-alloy high strength steels with tensile properties of about 120,000 psi or 750-860 N/mm2, such as Bisalloy 80, Sumiten 80S, T1, AISI4140 and Welten 80-C etc. These electrodes are supplied in a condition such that a particularly low hydrogen content of the deposited weld metal is ensured. For this reason it is imperative to prevent moisture pick-up when using these types. It is advisable that the operator should not take more electrodes than he needs for two hours welding. In unfavourable conditions of high humidity, it is recommended that an airtight container be used on site. The welding of high-strength steel is usually done by following the procedures given by the steel manufacturers and this should be carried out, if the mechanical properties of the HAZ are not to be affected. In most cases when welding root passes and first runs in standing fillets or tacking these steels, the use of Weldwell PH 56S or PH 77 is beneficial. The efficiency of PH 118 is 110-120% and this electrode is characterised by a fast efficient metal-transfer with deposits of excellent quality. In addition due to the chemical composition the impact properties at sub-zero temperatures are outstanding. Applications: Welding with PH 118 is very useful for repairing parts of machinery which are made of low-alloy high-strength steels, such as shafts, axles, forklift arms, etc.
Welding Techniques Welding with PH 118 can be done in all positions. The speed of travel should be low and the arc kept very short. If weaving is necessary "do it slowly". If these conditions are met the welds obtained will have excellent X-ray quality.
AWS A5.5 AS/NZS 1553.2
: :
E11018-G H4 E7618-G H5
WELDWELL
118 LOW HYDROGEN ELECTRODES FOR WELDING HIGH TENSILE STEELS
TIP COLOUR Violet FLUX MARKING PH 118 11018-G E7618-G Approvals: American Bureau of Shipping Welding Positions F, H,V, OH Typical Mechanical Properties of Weld Metal Tensile Strength 821 MPa Yield Value 775 MPa Elongation(1 = 5d) 24% Impact Value Charpy 81 J V Notch at -51oC Typical Chemical Analysis C 0.05% Mn 1.30% Si 0.30% Cr 0.02% Ni 1.60% Mo 0.50%
Recommended Amperages Dia. mm 3.2 4.0 5.0
Length mm 380 380 455
Amperes 90-140 110-180 170-240
Storage (See also page 88.) Once the packet has been opened, these electrodes should be stored in a heated cabinet at a temperature of 20oC minimum and/or at least 10oC above ambient. Good ventilation should be allowed.
Deposition Rate kg/hr* 1.20 1.62 2.30
For highest weld quality, these electrodes should be baked before use at 350oC for 1 hour to achieve a maximum weld metal hydrogen level of 10ml/100g or 400oC for 1 hour to achieve maximum weld metal hydrogen of 5ml/100g. Do not re-dry more than three times.
* Deposition Rate at maximum amps. AC 70V DC +
These temperatures should also be used to recondition damp electrodes. Use from a hot box during welding.
53
WELDWELL WELDING ELECTRODES ELECTRODES FOR WELDING CREEP-RESISTING STEELS Recommendations for welding creep-resisting steels Type of steel
Electrode Specification
Preheating and interpass temperatures Temperature
Stress relieving treatment
Plate thickness Temperature
Time in minutes
1.25 Cr/0.5 Mo
Weldwell KV5
150-200oC
All
680-700oC
2.5 x plate thickness in mm (min. 60 minutes)
2.25 Cr/1 Mo
Weldwell KV3
200-250oC
All
700-740oC
5 x plate thickness in mm (min. 120 minutes)
0.5 Cr/0.5 Mo/ 0.25 V
Weldwell KV3
200-300oC
All
680-720oC
2.5 x plate thickness in mm (min. 180 minutes)
Recommendations for storage and re-baking of Weldwell KV electrodes 1.
All basic-coated electrodes like the Weldwell KV electrodes should be stored in a dry place.
2.
It is advisable for the welder not to expose to the atmosphere more electrodes than will be needed for two hours of welding, at the same time keeping the remainder in an oven at 120 to 150oC, but the preferred procedure is to store electrodes at the welding site in a hot box at 70oC minimum for a maximum of eight hours.
3.
To achieve a maximum weld metal hydrogen level of 10 ml/100g these electrodes should be baked at 350oC for one hour, just before use.
4.
To achieve a maximum weld metal hydrogen level of 5 ml/100g these electrodes should be baked at 400oC for one hour, just before use.
5.
Electrodes which have been exposed to the atmosphere, and have become damp, should be rebaked, as detailed above.
54
DESCRIPTION: The all-position electrode Weldwell KV3, a basic coated type, is used for welding creep resisting steels alloyed with 2.25 Cr/1.0 Mo.
AWS A5.5 AS/NZS 1553.2
: :
E8015-B3L H4 E5515-B3L H5
WELDWELL
The Weldwell KV3 is also recommended for welding 0.5 Cr/0.5 Mo/0.25V steel. As a result of the stable arc and smooth weldability it is also very suitable for obtaining high quality welds when the Weldwell KV3 is used for welding tubes out of position. The welds are characterised by an excellent X-ray quality; the chemical composition of the weld metal guarantees a low sensitivity to solidification cracking.
ELECTRODES FOR WELDING CREEP-RESISTING STEEL TIP COLOUR FLUX MARKING
Welding Techniques Welding must be carried out with a short arc and a slow travel rate.
Recommended Heat Treatment A preheat and interpass temperature during the welding of 2.25 Cr - 1% Mo steels has to be 200 to 250oC for all plate thicknesses. Stress relieving must be carried out at 700 to 740oC, for a time in minutes equal to 5 x the plate thickness in mm for a minimum of two hours. Recommended Amperages Dia. Length mm mm 2.5 350 3.2 350 4.0 350
Aluminium PH KV3 8015-B3L
Approvals American Bureau of Shipping
Welding Positions F, H, V, OH Typical Mechanical Properties of Weld Metal Tensile Strength 726 MPa Yield Value 638 MPa Elongation 25% Typical Chemical Analysis C 0.05% Mo Mn 0.77% P Si 0.22% S Cr 2.10%
Amperes 65-95 75-130 115-165
0.95% 0.03% 0.01%
Storage Store in a dry place. (See page 54.)
DC only, positive polarity
Typical Creep Properties Temp
500oC 520oC 550oC 580oC
Min. creep strength F1/100,000 MPa Kg/mm2 MPa Kg/mm2
F1/10,000
147 128 84 59
15.0 13.0 8.5 6.0
108 89 59 39.5
11.0 9.0 6.0 4.0
Min. stress rupture strength FB/100,000 MPa Kg/mm2 MPa Kg/mm2
FB/10,000
207 168 114 79
21.0 17.0 11.5 8.0
158 118 79 54
55
16.0 12.0 8.0 5.5
Yield values at elevated temperature: 200oC: min. 440 MPa (45 kg/mm2) 250oC: min. 410 MPa (42 kg/mm2) 300oC: min. 390 MPa (40 kg/mm2) 350oC: min. 380 MPa (39 kg/mm2) 400oC: min. 375 MPa (38 kg/mm2) 450oC: min. 360 MPa (37 kg/mm2) 500oC: min. 350 MPa (36 kg/mm2)
DESCRIPTION: The WELDWELL KV5, a basic coated electrode, is employed for the all-position welding of creep resisting steels alloyed with 1.25 Cr/0.5 Mo.
AWS A5.5 AS/NZS 1553.2
: :
E7015-B2L H4 E4815-B2L H5
WELDWELL
It can also be used for welding of 0.9 Cr/0.5 Mo steels. Because of the excellent weldability, stable arc, the welding of tubes in all positions does not give rise to any problems. The weld metal of the Weldwell KV5 is insensitive to solidification cracking.
ELECTRODES FOR WELDING CREEP-RESISTING STEEL
Welding Techniques Welding must be carried out with a short arc and a slow travel rate.
Recommended Heat Treatment A preheating and interpass temperature of 150 to 200oC is generally required in welding large plate thicknesses. For thin plates a preheating temperature of 100 to 150oC will be sufficient. Stress relieving must be carried out at a temperature of 680 to 700oC, during a time in minutes equal to 2.5 x the plate thickness in mm for a minimum of one hour. Rapid cooling of the workpiece should be avoided.
TIP COLOUR FLUX MARKING
Green PH KV5 7015-B2L
Approvals American Bureau of Shipping
Welding Positions F, H, V, OH
Typical Mechanical Properties of Weld Metal Recommended Amperages Dia. Length mm mm 2.5 350 3.2 350 4.0 350
Tensile Strength Yield Value Elongation
Amperes 65-95 75-130 115-165
Typical Chemical Analysis C 0.04% Mo Mn 0.86% P Si 0.23% S Cr 1.20%
DC only, positive polarity
579 MPa 504 MPa 30%
0.46% 0.02% 0.01%
Storage Store in a dry place. (See page 54.)
Typical Creep Properties Temp 500oC 520oC 550oC
Min. creep strength Min. stress rupture strength F1/10,000 F1/100,000 FB/10,000 F/100,000 MPa Kg/mm2 MPa Kg/mm2 MPa Kg/mm2 MPa Kg/mm2 166 17.0 118 12.0 235 24.0 166 17.0 126 12.8 83 8.5 182 18.5 112 11.5 78 8.0 49 5.0 108 11.0 59 6.0
56
Yield values at elevated temperature: 200oC: min. 372 MPa (38 kg/mm2) 250oC: min. 352 MPa (36 kg/mm2) 300oC: min. 333 MPa (34 kg/mm2) 350oC: min. 323 MPa (33 kg/mm2) 400oC: min. 314 MPa (32 kg/mm2) 450oC: min. 304 MPa (31 kg/mm2) 500oC: min. 294 MPa (30 kg/mm2)
WELDWELL WELDING ELECTRODES ELECTRODES FOR WELDING STAINLESS STEELS In the welding of stainless steel a choice can be made from the following forms of joints, depending on the thickness of the material to be welded.
SQUARE BUTT WELDS
These are employed for sheets and plates with a thickness up to 4 mm (below 1 mm the TIG-welding process is used). The gap between the plates must be half the plate thickness. In connection with shrinkage the gap must be made 1 mm wider during tack welding, in order to ensure the required dimension of the root gap. The first weld is deposited on the side opposite to the one where the tack welds were made. After grinding, the side of the tack welds can be welded
SINGLE V-GROOVE
Single V-grooves are used for plate thicknesses of 5 up to 12 mm. It is necessary to bevel the groove faces so that good penetration is ensured. Root face of 2 mm is necessary in order to avoid overheating of the metal due to the low rate of heat transfer in stainless steel. The included angle must be 80o for plates of 5 to 7 mm. This angle should be 70o for thicknesses of 7 to 12 mm. These greater angles permit welding with an electrode having a larger diameter than in the case of unalloyed steels, so that the joint can be filled in fewer layers, which is favourable with regard to distortion.
DOUBLE-V GROOVE
For thickness over 10 mm the symmetrical double-V groove comes into consideration. A root face is not necessary here. The root run should always be ground out, in order to avoid welding-defects. Instead of the double-V grooves single U-grooves are also applied, especially for heavier plates.
TACK WELDING
Distortion of the workpiece as a result of tack welding can be reduced to the minimum by a favourable distribution of heat. It is a well known fact that straightening of austenitic stainless steel is very difficult and that it may affect the corrosion resistance. The use of tacking strips is not recommended, because then local stresses are introduced (stress corrosion). The tack welds should have a length of 40 mm; the distances between them should be as follows: Plate Thickness mm 1-1.5 2-3 4-6 Over 6
Distance between tack welds mm 25-40 40-70 70-100 100-150
RECOMMENDED WELDWELL ELECTRODES FOR WELDING VARIOUS GRADES OF STAINLESS STEEL IN GENERAL USE Parent Metals
Filler Metals
AISI Grades UNS (or common names) Number 301 S30100 302 S30200 304 S30400 304L S30403 309 S30900 310 S31000 316 S31600 316L S31603 318 S31800 2205 S31803 2304 S32304 Stainless Steel to Carbon Steel Molybdenum Bearing Stainless Steel to Carbon Steel *
Electrode Recommendation Weldwell PH RS308LC or RS347LC * Weldwell PH RS308LC or RS347LC * Weldwell PH RS308LC or RS347LC * Weldwell PH RS308LC or RS347LC * Weldwell PH RS309LC Weldwell PH BM310 Weldwell PH RM316LC or RM318LC Weldwell PH RM316LC or RM318LC Weldwell PH RM318LC Weldwell PH 22.9.3LR Weldwell PH 22.9.3LR Weldwell PH RS309LC Weldwell PH RS309MoLC Note: RM316LC or Staincord 316L-16 could also be used.
57
DESCRIPTION: This WELDWELL PH RS308LC electrode is used for welding austenitic stainless steels containing 16-20% chromium and 812% nickel. The non-stabilised weld metal is ductile, has a capacity for deformation and can be polished to a mirror finish. The smooth and finely rippled welds reduce grinding and polishing to the minimum. The electrode has good penetration properties and the slag is easy to control and to remove. Long welds can be made, reducing distortion to the minimum. Applications: Welding of stainless steels of similar composition in dairies, nuclear power plants, foodstuff and chemical industries, fertiliser plants, etc, when relatively mild corrosive attack can be expected. Welding Techniques The electrode should preferably be held at an angle of 80o to the direction of travel, and be welded with a SHORT ARC. Recommended Amperages Dia. Length Amperes mm mm 2.5 300 40-80 3.2 350 60-100 4.0 350 90-140 AC or DC + For AC a minimum open circuit voltage of 70V is required. Typical Mechanical Properties of Weld Metal Tensile Strength Elongation Typical Ferrite
AWS A5.4 AS/NZS 1553.3
: :
E308L-17 E308L-17
WELDWELL
ELECTRODES FOR WELDING STAINLESS STEEL TIP COLOUR FLUX MARKING
Brown PH RS308LC
Approvals American Bureau of Shipping Welding Positions: F, H, V, OH Typical Chemical Analysis C 0.03% Cr Mn 0.85% Ni Si 0.70%
19% 9.5%
Storage To recondition moist electrodes bake for one hour at 350oC in a vented oven.
642 MPa 38% 6.5%
DESCRIPTION: This is a heavily coated austenitic electrode for welding heatresistant materials, such as the type of steel containing 25% chromium and 20% nickel (AISI 310). In many cases these materials are used at temperatures exceeding 700oC. Another use is the welding of clad steels viz welding in the intermediate zone between mild steel and stainless material. Despite the fact that the weld metal mixes with ordinary mild steel, the weld metal will still contain a sufficient percentage of chromium and nickel, which guarantees that no martensite will be formed. The same applies to welded joints between ordinary mild steel and stainless steel. Welding Techniques The WELDWELL PHBM310 electrode produces a homogeneous weld with very good appearance and excellent heat resistance. The electrode has very low crack-sensitivity. Since the aforementioned types of steel are poor heat-conductors, a low current must be used for welding. For welding on direct current the electrode must be connected to the positive pole; in that case penetration is good. The arc must be kept short, both for downhand and for vertical position welding. Typical Mechanical Properties of Weld Metal Tensile Strength Min 550 MPa Elongation Min 30% Fully austenitic
AWS A5.4 AS/NZS 1553.3
: :
E310-16 E310-16
WELDWELL
ELECTRODES FOR WELDING STAINLESS STEEL TIP COLOUR FLUX MARKING
Blue PH BM310
Welding Positions F, H, V, OH Typical Chemical Analysis C 0.10% Cr Mn 1.76% Ni Si 0.39%
Recommended Amperages Dia. Length Amperes mm mm 2.5 300 50-75 3.2 350 70-95 4.0 350 90-120
26.3% 21.1%
Storage To recondition moist electrodes bake for one hour at 280oC in a vented oven.
DC + AC 70 OCV
58
DESCRIPTION: WELDWELL PH RM316LC is an electrode for welding austenitic stainless steels containing 16-20% Chromium, 1014% Nickel and 2-3% Molybdenum. Welding Techniques RM316LC is used to weld AISI 316 and 316L types such as encountered in petrol chemical, pharmaceutical, textile and paper industries. Like the steel to be welded, the weld metal has a superior resistance to pitting and to most types of corrosion, especially in reducing and neutral solutions. The welds obtained are smooth and finely rippled, slag-control is easy, and removal after cooling-down presents no problems. Welding should be carried out with a short arc; the electrode should preferably be held at an angle of 80o to the direction of travel. Recommended Amperages Dia. Length Amperes mm mm 2.5 300 40-80 3.2 350 60-100 4.0 350 90-140 5.0 350 130-180
AWS A5.4 AS/NZS 1553.3
: :
E316L-17 E316L-17
WELDWELL
ELECTRODES FOR WELDING STAINLESS STEEL TIP COLOUR FLUX MARKING
Orange PH RM316LC
Approvals American Bureau of Shipping Welding Positions: F, H, (V, OH for 4 mm and smaller)
AC 70 OCV DC + For AC a minimum open circuit voltage of 70V is required.
Typical Chemical Analysis C 0.02% Cr Mn 0.72% Ni Si 0.67% Mo
17.8% 11.40% 2.5%
Typical Mechanical Properties of Weld Metal Tensile Strength 600 MPa Elongation 41% Typical Ferrite 5.5%
Storage To recondition moist electrodes bake for one hour at 350oC in a vented oven.
DESCRIPTION: The WELDWELL PH RM318LC is an electrode designed for welding highly-alloyed austenitic types of Stainless Steels containing 16-20% chromium, 10-14% nickel and 2-3% molybdenum (AISI Type 318). The deposit has a high resistance to corrosion by strong acids. Naturally, the electrode can be used to weld steels of the AISI type 316. The presence of 3% molybdenum makes it suitable for the welding of stainless steels containing molybdenum in small quantities. The weld metal of the RM318LC is alloyed with niobium (or columbium), which guarantees that in the weld metal no intercrystalline corrosion will occur (stabilised material).
AWS A5.4 AS/NZS 1553.3
Welding Techniques The RM318LC electrode must be connected to the positive pole for welding on direct current; when welding is done with alternating current, an open circuit voltage of at least 70V is necessary. For welding, a short arc must be used because porosity may occur. The weld deposit is very smooth and finely ribbed, thus needing little finishing. Even at high currents the slag is easy to control and after welding it is very easy to remove. The angle between the electrode and the direction of travel must be approximately 80o. Typical Mechanical Properties of Weld Metal Tensile Strength Min 550 MPa Elongation Min 25% Typical Ferrite 7.2%
: :
E318-16 E318-16
WELDWELL
ELECTRODES FOR WELDING STAINLESS STEEL TIP COLOUR FLUX MARKING
Yellow PH RM318LC
Welding Positions F, H, (V, OH for 4.0 mm and smaller) Typical Chemical Analysis C 0.02% Cr Mn 0.77% Ni Si 0.72% Mo Niobium 0.24%
Recommended Amperages Dia. Length Amperes mm mm 2.0 300 25-60 2.5 300 40-80 3.2 350 60-100 4.0 350 90-140 5.0 350 110-170
18.0% 11.30% 2.50%
Storage To recondition moist electrodes bake for one hour at 350oC in a vented oven.
AC 70 OCV DC +
59
DESCRIPTION: Staincord 316L-16 is an extra low carbon, rutile type electrode exhibiting superior all positional (except vertical down) performance with an improved moisture resistant "Pink" flux coating for weld metal of high radiographic integrity. The smooth arc action of Staincord 316L-16, together with low spatter and excellent slag control/detachability, promotes exceptional weld appearance and profile. Other features include high arc stability and easy restriking on low voltage AC welding machines. Applications: Staincord 316L-16 deposits molybdenum bearing, 19Cr/12Ni/2.5Mo filler metal to meet the requirements for welding type 316 and 316L stainless steels in critical applications. Staincord 316L-16 is also recommended for the general purpose welding of common 300 series stainless steels, such as 301, 302, 304, and 304L. It is also suitable for the general welding of ferritic stainless steel alloys, such as 409, 444 and 3Cr12. (Contact your nearest Weldwell branch or distributor for further information on these applications.)
: :
E316L-16 E316L-16
WIA STAINCORD 316L-16 ELECTRODES FOR WELDING STAINLESS STEEL
TIP COLOUR FLUX COLOUR FLUX MARKING
Green Dust Pink 316L-16
Welding Positions: F, H, V, OH
Recommended Amperages Dia. Length Amperes mm mm 2.0 300 30-50 2.5 300 50-75 3.2 350 75-110 4.0 350 110-150
Typical Chemical Analysis C Mn Si
AC 45 OCV DC + Typical Mechanical Properties of Weld Metal Tensile Strength Elongation Typical Ferrite
AWS A5.4 AS/NZS 1553.3
0.025% 0.7% 0.7%
Cr Ni Mo
18.5% 12.0% 2.4%
Storage To recondition moist electrodes bake for two hours at 200oC . Do not exceed 250oC.
600 MPa 40% 5.5%
DESCRIPTION: The WELDWELL PH RS309LC is a rutile coated - all position electrode for welding stainless steel using 22-25% Cr and 1214% Ni. AISI 309 may also be used for welding dissimilar metals, eg stainless steel type 18/8 to mild steel. Also used for welding the buffer layer of 18/8 clad steels, of which the final run of the joint is made with PH RS308LC. Welding Techniques The electrode should be held at an angle of 80o to the direction of travel, and be welded using a short arc and a travel speed that allows good fusion of the parent metal. Typical Mechanical Properties of Weld Metal Tensile Strength Min 520 MPa Elongation Min 30% Typical Ferrite 12.4%
AWS A5.4 AS/NZS 1553.3
: :
E309L-17 E309L-17
WELDWELL
ELECTRODES FOR WELDING STAINLESS STEEL TIP COLOUR FLUX MARKING
White PH RS309LC
Welding Positions F, H, (V, OH for 4.0 mm and smaller)
Recommended Amperages Dia. Length Amperes mm mm 2.5 300 45-70 3.2 350 70-110 4.0 350 100-140 5.0 350 110-155
Typical Chemical Analysis C 0.03% Cr Mn 1.00% Ni Si 0.90% Mo
23.9% 13.1% 0.06%
Storage Store electrodes in a dry place. To recondition moist electrodes bake for one hour at 350oC in a vented oven.
AC 70 OCV DC +
60
DESCRIPTION: The WELDWELL PH RS309MOLC is an all position, rutile coated electrode which is extremely suitable for the welding of Molybdenum, containing austenitic stainless steels to carbon steels, and for the welding of buffer layers of AISI 316 clad steels of which the final run is made with PH RM316LC.
AWS A5.4 AS/NZS 1553.3
E309MoL-17 E309MoL-17
WELDWELL
Welding Techniques The electrode should be held at an angle of 80o to the direction of travel, and be welded using a short arc and a travel speed that allows good fusion of the parent metal. Typical Mechanical Properties of Weld Metal Tensile Strength 787 MPa Elongation 30% Typical Ferrite 18%
ELECTRODES FOR WELDING STAINLESS STEEL
Recommended Amperages Dia. Length Amperes mm mm 2.0 300 25-60 2.5 300 45-70 3.2 350 70-110 4.0 350 100-140 5.0 350 110-155 AC 70 OCV DC + Typical Chemical Analysis C 0.03% Cr Mn 0.81% Ni Si 0.60% Mo
TIP COLOUR FLUX MARKING
Violet PH RS309MOLC
Approvals American Bureau of Shipping Welding Positions: F, H, (V, OH for 4 mm and smaller) Storage Store electrodes in a dry place. To recondition moist electrodes bake for one hour at 350oC in a vented oven
22.20% 12.60% 2.70%
DESCRIPTION: WELDWELL PH 22.9.3LR is an all position, rutile coated electrode with some basicity. It is suitable for welding Duplex grades of stainless steel such as 2205, 2304 and 3RE60.
AWS A5.4 AS/NZS 1553.3
E2209-16 E2209-16
WELDWELL
Weldwell PH 22.9.3LR has a ferritic-austenitic structure, with a ferrite number of greater than 25 when measured with a severn gauge. It is resistant to inter-granular corrosion, and has very good resistance to pitting and stress corrosion cracking. Welding Techniques Welding is possible in all positions, except vertical down. Welding should be carried out using a short arc. Keep amperages as low as possible to achieve good fusion and weld pool control. The electrode has good re-ignition properties. Typical Mechanical Properties of Weld Metal Tensile Strength 882 MPa Elongation 22% Typical Ferrite > 45%
ELECTRODES FOR WELDING STAINLESS STEEL TIP COLOUR FLUX MARKING
Green PH 22.9.3LR
Approvals American Bureau of Shipping Welding Positions F, H, V, OH
Recommended Amperages Dia. Length Amperes mm mm 2.5 300 50-80 3.2 350 70-120 4.0 350 90-160
Typical Chemical Analysis C 0.03% Cr Mn 0.85% Ni Si 0.84% Mo N 0.17%
AC 50 OCV DC +
23.10% 9.80% 3.20%
Storage Store electrodes in a dry place. To recondition moist electrodes bake for one hour at 350oC in a vented oven.
61
WELDWELL WELDING ELECTRODES ELECTRODES FOR WELDING PROBLEM STEEL
Through the years many types of steels have been developed to suit specific kinds of work. In many cases they were not formed with the ultimate aim of weldability. The question often arises when a repair or such like is required, is what filler metal should be used, this is often difficult to answer without the material specifications. However, the so called rule of thumb can make these decisions much easier. Usually the part or body of the machine or implement etc will have been designed to suit a certain work force, ie strength in tensile or vibration, toughness and resistance to compression as in punch and die tooling. There are three types of electrodes in the ELITE range, RSP, Hi Ten 7 and Hi Ten 8. Each is listed with its own description, which in most cases will enable the end user to select a suitable welding electrode for that problem weld. Please remember that Weldwell do have technical people who can assist and we advise - IF IN DOUBT, PLEASE ASK US.
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DESCRIPTION: ELITE RSP is a rutile-coated electrode depositing a weld metal of an austenitic-ferritic structure, which is highly crack resistant. Hence its use for welding Problem Steels where the risks of cracking do occur. Elite RSP deposits a smooth dense weld and its slag releases very easily. It can be used to join steels which differ from one another, ie stainless and mild steel. The Elite RSP is also suitable to weld creep-resistant steels such as 5% Cr - 0.5% Mo steel, where no heat treatment can be applied after welding. It is most appropriate for joining highalloy and/or low-alloy steels which differ from one another. Due to the type of composition the weld metal is highly acceptable for buffer layers prior to hard surfacing because of its toughness and ability to absorb stresses. Although the appearance is similar to stainless steel, Elite RSP should not be used as a corrosion-resistant alloy and is not stabilised.
ELECTRODES FOR WELDING PROBLEM STEELS
TIP COLOUR FLUX MARKING
Recommended Amperages Dia. Length Amperes mm mm 2.5 300 40-75 3.2 350 60-100 4.0 350 90-140 5.0 350 130-180 AC 75V
WELDWELL ELITE
Gold Weldwell RSP
Welding Positions: F, H, (V, OH for 4 mm and smaller) Typical Chemical Analysis C Max 0.04% Cr 17.0-20.0% Mn Max 2.50% Ni 10.0-14.0% Si Max 1.00% Mo 2.0-3.5%
DC +
Typical Mechanical Properties of Weld Metal Tensile Strength 640-750 MPa Elongation(1 = 5d) Min. 25% Deposited 200 Brinell Work Hardens to 500 Brinell Typical Ferrite 22%
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Storage To recondition moist electrodes bake for one hour at 350oC in a vented oven.
DESCRIPTION: ELITE HI-TEN 8 has a special coating which permits smooth, dense deposits, porosity free and with little or no spatter. Welds are made with highest possible speed using the lowest practical amperage, the deposit will take a high polish.
WELDWELL ELITE
Exceptionally good where high strength, impact, heat and corrosion resistance are required. It is very insensitive to cracking. Recommended for use when the analysis of the various stainless steels is unknown or doubtful, the repair of die and tool steels. Elite Hi-Ten 8 can not be heat treated, but can be work hardened to over 1200 MPa tensile strength. Typical Applications Elite Hi-Ten 8 is used in the jet aircraft, coal mining, chemical, oil and gas industries. The general engineering industry finds it exceptional for welding spring steels, dies, gears, pumps, shafts, nickel-clad steels, tools and saltwater pumps. It will weld or overlay aluminium bronzes with very good results. Ideal to repair or overlay petrol engine exhaust valves. Welding Techniques Ensure that weld areas are thoroughly cleaned and follow rules for good joint preparation. AC or DC reverse polarity, ie electrode positive. When applying in some of the high alloy steels a preheat of approximately 200-300oC ie a "light blue colour" is recommended. It is good practice before commencing welding to make test runs on scrap steel to ensure that the amperage condition is ideal. In most cases use stringer beads and let each pass cool prior to flux removal. A short arc is very necessary. Peening will remove internal stresses. When using multi-passes ensure that the slag is completely removed with each pass. Recommended Amperages Dia. Length Amperes mm mm 2.5 300 40-75 3.2 350 75-125 4.0 350 90-140 AC 50V
DC +
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ELECTRODES FOR WELDING PROBLEM STEELS
TIP COLOUR FLUX MARKING
Light Blue Weldwell Hi-Ten 8
Welding Positions F, H, V, OH
Typical Mechanical Properties of Weld Metal Tensile Strength Tensile Strength Yield Strength Elongation in 50 mm Hardness Typical Ferrite
As deposited up to 825 MPa Work hardened up to 1200 MPa Up to 625 MPa Minimum 22% 200 Brinell > 45%
Storage To recondition moist electrodes bake for one hour at 350oC in a vented oven.
WELDWELL WELDING ELECTRODES ELECTRODES FOR GOUGING AND CUTTING
There are conditions when metals need to be removed or parted and sometimes the oxygen-acetylene system is not always suitable. There are two types in the range which perform very well, these are the AUSTARC C&G and the WELDWELL PH C18. With powerful arc welding machines the type AUSTARC C&G is the most efficient, with the PH C18 working very well where the power supply is not so high. These types will operate successfully on steels, cast irons, copper base, stainless, nickel and aluminium metals.
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DESCRIPTION: Austarc C & G is a heavy coated electrode providing a highly mobile means of cutting, gouging and piercing most steels, using standard AC or DC arc welding equipment. Austarc C & G produces a very high arc force and can be used for general cutting and grooving in joint preparation, removing defective welds and reclaiming scrap metal, etc.
AUSTARC C&G
Typical Applications Oxy-acetylene and carbon arc-air cutting and gouging are two processes available to industry capable of giving high quality, smooth preparations. Austarc C & G will not replace these processes but rather provide a convenient, easy to use and mobile tool for the arc gouging and cutting of most metals. It is particularly useful to the maintenance welder operating in awkward locations to remove welds, open up joints and trim off bolt or rivet heads, etc.
ELECTRODES FOR GOUGING AND CUTTING
Welding Techniques Cutting: Direct the electrode into the work in the desired cutting direction, working from the outside edge. Use an up and down sawing motion, the “up” arc length being increased to increase heating, the “down” arc length being decreased to contact point to force the molten metal out of the groove. Angle of electrode should be approximately 70o to the horizontal.
TIP COLOUR
Gouging: Point the electrode in the direction of gouging at approximately 10-20o to the plate surface. Strike the arc and move forward rapidly. If slag and molten metal start to clog the groove bring the electrode up to clear, and, without breaking the arc, circle backwards and move forward again. This latter technique may prove more necessary than straight forward motion on lower amps or as the electrode becomes hotter. If amps are excessive, C & G will tend to “cut out” on AC and overheat, causing premature charring of the coated and reduced arc force.
AC 70 OCV or DC +
Piercing: For holes, plunge the electrode into the plate at slightly off right angles. With a small circular motion to the holder, force the electrode into the plate until full penetration is achieved. Once the hole has been made it may be trimmed with an up and down sawing motion. WARNING: The fire hazard potential of arc cutting is much greater than for welding, therefore ensure the arc is clear of all flammable materials before proceeding. Do not cut on or near oil drums, gas cylinders, etc.
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PLAIN
Recommended Amperages Dia. Length mm mm Amperes 3.2 380 170-250 4.0 380 220-350
Storage Store electrodes in a dry place. Note: As these electrodes demand very high arcing volts, it must be taken into account that the amperes indicated by mechanical means on welding machines will be much lower and therefore compensation adjustment will be necessary. In addition when comparing AC to DC in values, it is normal to add 15% to the AC range to allow for the slightly weaker AC value.
WELDWELL WELDING ELECTRODES ELECTRODES FOR WELDING CAST IRON
Cast iron contains 3-5% carbon and smaller quantities of silicon and manganese; phosphorus and especially sulphur are undesirable impurities. Alloyed cast irons may also have additions of nickel, molybdenum, chromium or copper. In normal grey cast iron the carbon is present in the form of flakes of free graphite which is responsible for the comparatively low tensile strength. With special metallurgical techniques cast irons with improved properties can be produced, the effect being that the strength impairing flakes of graphite are replaced by nodules of graphite. These ductile irons (nodular cast irons; spheroidal cast irons; SG irons) are more ductile and have tensile strengths two to three times that of grey iron. Both grey cast iron and ductile iron are weldable. As may be expected, the latter is easier to weld than grey iron, which is more likely to develop fusion-line and base-metal cracks. However relatively little is demanded of joints in this material in terms of mechanical properties, since service stresses are mainly compressive. Cast iron must be joined with adapted welding-techniques and suitable weld metal compositions. The major part of cast-iron welding is carried out with nickel base electrodes designed for low energy input, ie "Low Heat". Low Heat input restricts expansion and contraction stresses, which, due to the low degree of plastic deformation of the base metal, easily result in cracks. Moreover, the zone adjacent to the weld develops, under the influence of the welding-heat and the inherently fast cooling-rates, undesirable hard and brittle structures. The depth of this zone is relative to the heat input. Nickel-based electrodes have emerged as the most satisfactory filler metal for the welding of cast irons, generally because of their good ductility and bond strength and their ability to precipitate the carbon picked up from the base metal in the form of free graphite. The commonly used nickel-based electrodes are represented in the Weldwell range by the Supercast Ni containing over 96% nickel and the Supercast Ni Fe, a 60/40 nickel-iron type. These electrodes operate on a low current intensity and a low arc voltage, thus ensuring minimum heat input. The Austarc 16TC electrode is ideally suitable for the welding of dirty and heat affected cast iron, where machine ability is not necessary. Also suited for buttering and sealing runs prior to using Supercast Ni.
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DESCRIPTION: Supercast Ni is a basic, graphite-coated AC/DC electrode for the lower strength welding of cast irons. It is characterised by a soft, smooth arc with low penetration and spatter levels on both AC and DC power sources. Ease of striking is a feature of Supercast Ni and it also has a particularly good wetting action resulting in well bonded welds of regular contour and attractive appearance.
AWS A5.15
WELDWELL
This electrode is made from a pure nickel core wire and produces a ductile, fully machinable weld deposit. Supercast Ni may be used for the repair and reclamation of all standard grades of grey cast iron, malleable iron, austenitic cast iron.
ELECTRODES FOR WELDING CAST IRON
Recommended Amperages Dia. mm 3.2 4.0
Length mm 350 350
AC 45 OCV
Amperes
E Ni - Cl
TIP COLOUR
50-100 80-130
Welding Positions: F, H (V, OH for smaller sizes)
DC + or -
Typical Mechanical Properties of Weld Metal Tensile Strength 400 MPa Yield Value 220 MPa Deposit Hardness 150-170 HV (30)
DESCRIPTION: Supercast Ni Fe is a basic, graphite-coated AC/DC electrode for the higher strength welding of cast irons. It is characterised by a soft, smooth arc with low penetration and spatter levels on both AC and DC power sources. Ease of striking is a feature of Supercast Ni Fe. This electrode is made from a nickel-iron core wire and produces a ductile, machinable weld deposit with the extra strength required for welding SG (spheroidal graphite) irons. Supercast Ni Fe may also be used for the repair and reclamation of all standard grades of grey cast iron, malleable iron, austenitic cast iron. It is ideally suited to the dissimilar welding of these irons to steels.
Typical Chemical Analysis Nickel 97.0% Manganese 0.03% Silicon 0.006% To recondition moist electrodes bake for one hour at 150o in a vented oven.
AWS A5.15
E NiFe - Cl
WELDWELL
ELECTRODES FOR WELDING CAST IRON TIP COLOUR
Recommended Amperages Dia. Length Amperes mm mm 3.2 350 50-100 4.0 350 80-130 AC 45 OCV
PLAIN
GREEN
Welding Positions: F, H, (V, VD, OH for smaller sizes) Typical Chemical Analysis Nickel 57.8% Manganese 0.85%
DC + or -
Typical Mechanical Properties of Weld Metal Tensile Strength 500 MPa Yield Value 300 MPa Deposit Hardness 200-220 HV (30)
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To recondition moist electrodes bake for one hour at 150o in a vented oven.
WELDWELL WELDING ELECTRODES ELECTRODES FOR HARDFACING
Hardfacing is applying wear-resistant alloys on a metal surface, to improve the wear resistance of components subject to abrasion, impact, heat and corrosion, or a combination of these. The purpose of the hardfacing is primarily to increase the service time of the component, thus limiting shut-down time. In addition, and this is often overlooked, production rates and quality of the product are frequently considerably improved. The alloys used in combating wear are usually classified according to their functions as build-up alloys and hard facing alloys. In general practice badly worn components are restored to size by the softer and less wear-resistant build up alloys, which possess good deformation resistance and provide good support for the hard-surfacing alloy. The latter has been designed to give maximum resistance to a specific form of wear or to a combination of wear factors. The wear resistance of the hardfacing deposit depends on the amount of carbides (chromium, tungsten, molybdenum carbides, etc) and on the matrix, which through alloying with elements such as nickel, manganese, silicon and cobalt, can be given specific properties for optimum performance under certain service conditions. Though abrasion is involved in most cases, sometimes conditions call principally for greater toughness, and when heavy impact or metal-to-metal wear with heavy impact dominates, austenitic manganese steel is the preferred material. Surfacing electrodes yielding a 13% manganese deposit are often employed to rebuild 13% manganese steel, but also as an overlay deposited on a carbon-steel base. It is a good thing to bear in mind that the properties of the hard surfacing alloy stated by the manufacturers usually relate to those of the pure weld metal. However, hardness and structure can be appreciably affected by dilution of the deposit with the parent metal. Generally speaking little effect is apparent after the third layer. Cooling-rates can likewise modify the structure, and hence the wear resistance, of some of the hard facing alloys (air-hardening types). Selection of the hard facing alloy should be after careful analysis of the service conditions. Data relevant to mechanical and physical properties of the weld metal and base metal should be taken into consideration and a welding-procedure be established accordingly. Rather than the "try-and-see" method, this approach to wear will ultimately result in the highest savings.
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DESCRIPTION: The WELDWELL PH MN is a basic coated hard facing electrode which deposits a 13% manganese weld metal which is very tough and dense, with a high yield and tensile strength. The high work-hardening capacity of PH MN makes it very suitable for withstanding heavy impact loads. It performs well in cases of metal to metal wear. The weld metal of the PH MN is less sensitive to embrittlement due to carbide precipitation than conventional 13% manganese electrodes, yet has the same compressive strength. The deposit can be flame-cut. The PH MN is used as a final overlay when impact values are too high for hard facing, and for rebuilding austenitic manganese base materials prior to the application of a more abrasion-resistant overlay. Whenever unalloyed or low alloy steel must be covered with this type, it is necessary to apply a buffer layer of Weldwell Elite RSP weld metal. The tough layers then absorb the high contractional stresses caused by the high coefficient of thermal expansion and low thermal conductivity of 13% manganese steel (Hadfields).
Welding Techniques The PH MN is used in the downhand position. Craters should be filled up through reversal of the direction of travel. When welding is done on the manganese steel it is essential to prevent heat build-up in the component. Therefore welding with little or no weaving, while a short arc is maintained, and using minimum current are recommended. For the same reason it is advisable to cover the surface evenly with a pattern of short beads approximately 100 mm in length, each bead at a distance of at least 150 mm from the preceding one and to fill up the spaces in between according to the same procedure. Heavy peening immediately after welding is recommended to stress-relieve the weld. Artificial cooling by a stream of water or partial immersion in water are beneficial aids for gaining high cooling rates. Applications Crusher jaws and rolls, impact bars, hammers, ball and tube mill liners, rail frogs and switch points, shovel bucket and teeth, manganese steel castings, etc.
AWS A5.13 AS/NZS 2576
: :
E Fe Mn-B 1220-A4
WELDWELL
ELECTRODES FOR HARDFACING TIP COLOUR FLUX MARKING
Blue PH MN
Welding Positions: F, H Recommended Amperages Dia. Length Amperes mm mm 4.0 380 125-170 AC 60 OCV
DC +
Typical Undiluted Hardness As Welded Vickers Brinell Rockwell
250 HV 250 HB 25Rc
After Work Hardening 540 HV 495 HB 50Rc
Typical Chemical Analysis C 0.6% Mn 14.8% Mo 0.9% Storage Store electrodes in a dry place. To recondition moist electrodes bake for one hour at 350oC in a vented oven.
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DESCRIPTION: The WELDWELL PH 250 is an electrode which deposits strong, tough and machineable weld material.
AS/NZS 2576
:
1120-A4
WELDWELL
The application of this electrode is specially suited to the reinforcing of tram and railway rails by depositing a tough surface on rails and crossings. It is also used for the resurfacing of axles, lightly-alloyed steels, and the edges of dies. The composition of the weld deposit corresponds, with respect to carbon and manganese contents, to that of the steel used for modern rails. The hardness of the deposited metal depends upon the number of layers, upon the speed with which the material cools, and upon the temperature of the work-piece. By quenching the deposited metal at a temperature of 816-904oC in water, a Brinell hardness of about 400 can be obtained. By quenching at a temperature of 954oC in oil, a Brinell hardness of about 350 is achieved. Grinding tends to increase the surface hardness of the deposit. Due to the fairly heavy iron powdered coating the PH 250 electrode can take higher currents which increase the deposition rates to approximately 120% efficiency. The hardness of PH 250 weld metal is low enough to make it easy to machine, so that it finds use for facing components which require only moderate wear resistance, and which have to be machined after building up, as often as necessary on shafts, axles and other machinery parts. The weld deposit is readily carburised for case hardening.
ELECTRODES FOR HARDFACING
TIP COLOUR FLUX MARKING
Green PH 250
Welding Positions: F, H Recommended Amperages Dia. Length Amperes mm mm 3.2 380 95-145 4.0 450 125-180 AC 50 OCV
DC + or -
PH 250 can be applied as a build up prior to using higher hardness electrode weld metal deposits
Typical Undiluted Hardness Vickers 250 HV) Brinell 250 HB) Refer to text above Rockwell 24RC)
Applications: Tractor sprockets - Idler shafts - Carbon steel rails - Wheel assembly shafts - building up of parts which require subsequent machining.
Typical Chemical Analysis C 0.1% Mn 0.83% Si 0.4%
Welding Techniques No special precautions are necessary when overlaying mild or medium tensile steels. A preheat is desirable when dealing with the hardenable carbon or alloy steels, this is to avoid hard zone cracking beneath the weld deposit.
Storage Store electrodes in a dry place. To recondition moist electrodes bake for half an hour at 120oC in a vented oven.
If the type of steel is not known a preheat of 150o-205oC and the use of a buffer layer of PH 77 or PH 56S weld metal ensures a result which is safer with most types of hardenable steels which could be encountered.
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DESCRIPTION: The WELDWELL PH 250 is an electrode which deposits strong, tough and machineable weld material.
AWS A5.13 AS/NZS 2576
The application of this electrode is specially suited to the reinforcing of tram and railway rails by depositing a tough surface on rails and crossings. It is also used for the resurfacing of axles, lightly-alloyed steels, and the edges of dies.
E Fe2 1120-A4
:
WELDWELL
The composition of the weld deposit corresponds, with respect to carbon and manganese contents, to that of the steel used for modern rails. The hardness of the deposited metal depends upon the number of layers, upon the speed with which the material cools, and upon the temperature of the work-piece. By quenching the deposited metal at a temperature of 816-904oC in water, a Brinell hardness of about 400 can be obtained. By quenching at a temperature of 954oC in oil, a Brinell hardness of about 350 is achieved. Grinding tends to increase the surface hardness of the deposit. Due to the fairly heavy iron powdered coating the PH 250 electrode can take higher currents which increase the deposition rates to approximately 120% efficiency.
ELECTRODES FOR HARDFACING
TIP COLOUR FLUX MARKING
Green PH 250
Welding Positions: F, H
The hardness of PH 250 weld metal is low enough to make it easy to machine, so that it finds use for facing components which require only moderate wear resistance, and which have to be machined after building up, as often as necessary on shafts, axles and other machinery parts.
Recommended Amperages Dia. Length Amperes mm mm 3.2 380 95-145 4.0 450 125-180 5.0 455 190-280
The weld deposit is readily carburised for case hardening.
AC 50 OCV
DC + or -
PH 250 can be applied as a build up prior to using higher hardness electrode weld metal deposits
Applications: Tractor sprockets - Idler shafts - Carbon steel rails - Wheel assembly shafts - building up of parts which require subsequent machining. Welding Techniques No special precautions are necessary when overlaying mild or medium tensile steels. A preheat is desirable when dealing with the hardenable carbon or alloy steels, this is to avoid hard zone cracking beneath the weld deposit. If the type of steel is not known a preheat of 150o-205oC and the use of a buffer layer of PH 77 or PH 56S weld metal ensures a result which is safer with most types of hardenable steels which could be encountered.
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Typical Undiluted Hardness Vickers 250 HV) Brinell 250 HB) Refer to text above Rockwell 24RC) Typical Chemical Analysis C 0.1% Mn 0.83% Si 0.4% Storage Store electrodes in a dry place. To recondition moist electrodes bake for half an hour at 120oC in a vented oven.
DESCRIPTION: The WELDWELL PH 600 is a heavy coated iron powder electrode which deposits a weld metal containing carbon chromium and manganese. This resultant deposit is martensitic, containing finely divided chromium carbides which are highly resistant to abrasive wear, and also have very good properties against sliding and rolling friction.
AWS A5.13 AS/NZS 2576
: :
E Fe 3 1855-A4
WELDWELL
PH 600 is not recommended for loads encountering high impact. The deposit is malleable when hot and therefore is forgeable. When applied as a deposit without dilution PH 600 exhibits a Brinell hardness of approximately 600. This hardness can be varied if slow cooling is used or by quenching in water. The weld metal will not stand large shrinkage stresses, therefore in some cases where the deposits are heavy, a preheat may be desirable. Machining of the deposit is not recommended, and grinding is the usual method. Often, intermediate layers made with "softer" electrodes are employed; a layer of PH 600 can be preceded by a layer of, for instance, WELDWELL PH 77 or PH 250 or PH 400. These tougher deposits will then absorb the stress resulting from the PH 600 deposit. There is another group of electrodes of the austenitic type which are sometimes employed for this use, namely Weldwell Elite RSP. These are deposited in alternate beads with PH 600. As a result the resistance to impact loads increases largely whilst the hardness decreases very little. Applications PH 600 electrodes may be used to reclaim tips of excavator tools, dredging bucket rims, hammers of hammer mills, etc. New manganese steel which is soft before work hardening is often overlayed with PH 600 to counter the initial rapid wear period whilst work hardening occurs. Some Typical Applications are Bulldozer blades Harrow tynes Swing hammers Ploughshares Crusher jaws Shear blades Cultivator blades Ripper teeth Picks and mattocks Bucket teeth and lips Dies Cutter heads Excavator teeth Mover shoes Track pads Post hole diggers Chutes Chisels and anvils
ELECTRODES FOR HARDFACING
TIP COLOUR FLUX MARKING
Pink PH 600
Welding Positions: F, H, (V, OH for 2.50 mm) Recommended Amperages Dia. Length Amperes mm mm 3.2 380 95-145 4.0 455 125-180 5.0 455 190-280 AC 50 OCV
DC + or -
Typical Undiluted Hardness Vickers 741 HV) Brinell 614 HB) Refer to text above Rockwell 59RC) Typical Chemical Analysis C 0.40% Mn 0.74% Si 0.41% Cr 5.30% Storage Store electrodes in a dry place. To recondition moist electrodes bake for half an hour at 120oC in a vented oven.
Welding Techniques The welding characteristics of PH 600 are similar to WELDWELL PH 250, therefore please refer to the PH 250 description.
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DESCRIPTION: The WELDWELL PH 700 electrodes when welded, deposit a High Chromium, High Carbon type alloy commonly known as Chromium Carbide. A mild steel core wire with a high alloy content and heavy coating permits the use of fairly high currents and fast deposition rates.
AS/NZS 2576
:
2360-A4
WELDWELL
The PH 700 alloy is designed to combat the effects of both abrasion and impact, because the micro-structure of the deposit consists of very hard chromium carbide particles (up to 1700 VPN) imbedded in a tough matrix of austenite (approximately 400 VPN). The high chromium content allows the weld deposit very good resistance to corrosion and scaling at high temperatures (up to 980oC).
ELECTRODES FOR HARDFACING
Due to the fact that the coefficient of thermal expansion of 30% Cr steel is about 50% higher than carbon steel, small cracks can be expected in the deposited weld metal. These will have no adverse influence on the wear-resistance, because stresses will be eliminated, thus reducing the risk of crumbling of the weld metal.
TIP COLOUR FLUX MARKING
PH 700 can only be sized by grinding because the deposit cannot be softened by annealing.
Welding Positions: F, H
Welding Techniques PH 700 electrodes can be used over a wide current range and have a very stable arc with low open circuit voltage AC machines. When first striking, a medium to long arc is held for a few seconds to create a hot pool which allows a flat deposit to form, but a short arc should be held during welding so as to reduce chromium loss due to oxidation.
Recommended Amperages Dia. Length Amperes mm mm 3.2 380 110-130 4.0 380 130-180 5.0 380 150-220
Either stringer bead or a weaving technique may be employed. A weave three or four times the electrode diameter allows the shape of the deposit to be controlled for smoothness and flatness.
AC 50 OCV
As with general practice the PH 700 can be hardness controlled by the use of higher currents for greater weld deposit dilution, which allows for better impact properties. When low currents are used, then the weld deposit reaches its highest hardness for superior abrasion resistance. In general, a single layer deposit is recommended, but multi layers may be used to combat high abrasion in service. The deposit hardness of PH 700 on austenitic manganese steel is reduced, but this condition is excellent for heavier impact loads. Applications Furnace parts Rolling mill guides Conveyor screws Brick machines Feed spouts Muller tyres Dozer blades Ripper teeth
Bucket lips Chutes Ploughshares Drag chain links Pins and rider blocks Wire straightening rollers Cement mill mixers, chutes, etc.
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Red PH 700
DC + or -
Typical Undiluted Hardness Vickers 820 HV) Brinell 653 HB) Refer to text above Rockwell 62RC)
Typical Chemical Analysis C Minimum 3% Cr Minimum 18%
Storage Store electrodes in a dry place. To recondition moist electrodes bake for half an hour at 150oC in a vented oven.
DESCRIPTION: Abrasocord 43 is a heavy coated, hard surfacing electrode depositing a complex, extremely hard, abrasion resistant chromium/niobium carbide in an austenitic matrix. It is ideal for hard surfacing applications where resistance to extreme abrasion and moderate to heavy impact are required. Due to the nodular shape of the complex carbides, Abrasocord 43 deposits are capable of withstanding heavier impact levels than standard chromium grades. Welding Techniques Abrasocord 43 deposits are non-machinable, grindable, prone to fine relief checking and should be restricted to three layers high.
AS/NZS 2576
2465-A4
WELDWELL
ELECTRODES FOR HARDFACING
While two layers of Abrasocord 43 may be required for maximum wear resistance, this complex carbide alloy has lower dilution sensitivity than straight chromium carbide deposits.
TIP COLOUR
Applications Typical applications include bucket teeth/lips, grizzlies, press screws, crusher hammers and ripper teeth to name but a few.
Welding Positions: F, H
Recommended Amperages Dia. Length Amperes mm mm 3.2 380 115-140 4.0 380 140-185 AC 55 OCV DC +
:
PLAIN
Typical Chemical Analysis Carbon 5.0% Manganese 0.7% Chromium 22% Niobium 7% Storage Store electrodes in a dry place. To recondition moist electrodes bake for two hours at 200oC in a vented oven.
Typical Mechanical Properties - Hardness Single layer onto Mild steel 60-65 HRc Multi-layer 64-69 HRc
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DESCRIPTION: Vidalloy 11 contains a minimum of 60% Tungsten Carbide classified as a diamond substitute and has the highest resistance to abrasion of any commercially produced product. The electrode body consists of a thin walled tube densely packed with coarse mesh cast tungsten carbide particles. When welded the rough shaped tungsten carbide particles are embedded in a tough alloy steel matrix and impart excellent cutting efficiency. Hardness Rating Single layer deposits on mild steel give a carbide hardness of 1800 VPN. If a finish is required then grind using special wheels. Welding Position Where necessary 6.3 mm Vidalloy 11 can be used in the vertical and overhead position. No Special Storage The electrodes are completely moisture resistant because of the non-hygroscopic flux coating. Relief checks are normal. Fluidity is very good. Fume factor low. Deposits May be made on cast iron, mild steel, low alloy steels, stainless steels and austenitic manganese steels without preheat. High carbon steels should be preheated to 500oC before welding and allowed to cool slowly. Recommended Amperages Dia mm 6.3
Amperes 90-145
AC 50 OCV
Approx area covered per kg 3.25 mm thick = CM2 274-284
Approx No per kg 9.26
AS/NZS 2576
:
3360-A1
VIDALLOY
ELECTRODES FOR HARDFACING TIP COLOUR
Gold
Welding Positions: F, H, V, OH Typical Undiluted Hardness Vickers 1800 HV MOH Scale 9.9 Applications: Bucket teeth, Bulldozer end tips, Trencher teeth, Oil drill collars, Reamers, Posthole auger blades, Churn drills, Raymond mill ploughs, Bituminous mixer blades, Coal cutter bits, Diamond core drills
Approx deposition rate Kg per hour 1.5 - 2
DC + or -
DESCRIPTION: Vidalloy 30 deposits an alloy known as Chromium Carbide Austenitic Iron and when applied to a mild steel base the nominal composition is Carbon 5%, Chromium 35%, Manganese 3.5%, balance Iron. Hardness Figures Single layer deposit 500-600 Brinell. 630-675 Brinell.
:
2355-A1
VIDALLOY
Multi layer deposit
No Special Storage The electrodes are completely moisture resistant because of the non-hygroscopic flux coating. The stub end allows even the 11 mm diameter electrode to fit most conventional electrode holders. Vidalloy has very little spatter and a low fume factor. Relief checks are normal. Finish by grinding only. The high alloy content in the deposited metal is the main reason for superior service life results. Vidalloy contains the highest amount of deposited metal per kg of electrodes. Contains the highest and best balanced proportions of alloying elements which means longest life for the lowest cost outlay. Typical Undiluted Hardness Single Layer Vickers 567 HV Brinell 514 HB Rockwell 52Rc
AS/NZS 2576
Multi Layer 717 HV 601 HB 58Rc
Recommended Amperages Approx area Dia Approx No covered per kg mm Amperes per kg 3.25 mm thick = CM2 6.3 80-125 12.4 144-155 8.0 140-190 5.4 155-180 11.0 190-250 4.0 180-206 The 6.3 mm diameter is designed for all positional welding. AC 50 OCV DC + or -
76
ELECTRODES FOR HARDFACING TIP COLOUR
Red
Welding Positions: F, H, (V, OH for 6.3 mm)
Applications: Parts subject to severe abrasion and good impact resistance. The deposited alloy gains a high polish in wear and has a high erosion factor. Examples are: Swing hammers, fixed hammers, blow bars, shovel buckets, dragline buckets, bucket teeth, lips, crusher rolls (rock and shale), gums and bottoms, Cement ball mill, Liner plates (dry), Augers, Scraper blades, Brickpan tyres. Note: Excessively high amperages result in greater dilution with base metal.
Approx deposition rate Kg per hour 1.65 - 2.50 2.50 - 2.75 3.00 - 4.00
WELDWELL WELDING ELECTRODES ELECTRODES FOR SPECIAL METALS
These types are for the brass and bronzes and for aluminium. BRONZE ARC is a general purpose phosphor bronze electrode. ALLY-ARC is for welding aluminium castings and extrusions.
77
DESCRIPTION: BRONZE-ARC is a phosphor bronze alloy with an extruded coating which gives exceptional arc stability. With this versatile electrode you can "arc braze" the same as you "arc weld" using a DC arc welding machine.
AWS A5.6
Typical Applications Bronze-Arc may be used to weld or overlay cast or malleable irons which are oil soaked, extremely dirty, rusty or burned. It will give excellent results where many others fail. In addition, it will braze cast iron or steel, bronzes or brasses, etc. Very useful for some of the many problems involved in maintenance welding shops. Welding Techniques Clean all joint areas by removal of scale, dirt, grease and soft solder which may be there. Materials over 5 mm thick should be bevelled, a double-vee if possible. Because copper and its alloys conduct heat rapidly, a preheat is essential to avoid non bonding, non flowout and porosity. With sufficient preheating the alloy from BronzeArc will flow readily, using low amperages. Multiple passes will add extra heating making for easier welding or brazing. Each pass should be thoroughly cleaned, whilst peening will increase the strength and toughness. Preheat thick sections to 200oC. Weld, using a medium to long arc length. Carry arc on to the leading edge of the weld pool and do not weave wider than four times the electrode diameter. Avoid deep penetration and over heating because cracking and porosity may result.
78
E CuSn-C (Closest)
WELDWELL
The Bronze-Arc alloy has good saltwater and general corrosion resistance and colour match comparable to red bronzes. Bronze-Arc may be used to fabricate and join phosphor bronzes, copper alloys and some iron base metals. It has a relatively high strength, ductility, free flowing and crack resistant characteristics. It is particularly suited for surfaces exposed to corrosion. Copper alloys of high lead content will require two or three passes of Bronze-Arc to produce porosity free welds. Brasses of high zinc content should be welded with very little fusion. Certain variations will occur due to the welding conditions.
:
ELECTRODES FOR WELDING SPECIAL METALS
TIP COLOUR
Green
Recommended Amperages Dia. Amperes mm 3.2 100-150 4.0 125-190 DC + Typical Mechanical Properties of Weld Metal Tensile Strength Up to 414 MPa Yield Point Up to 240 Brinzell Hardness 85-100 HB Storage Store electrodes in a dry place. To recondition moist electrodes bake for one hour at 95oC in a vented oven.
DESCRIPTION: ALLY-ARC is an aluminium electrode with an extruded covering. It operates smoothly, with an easy to control quiet arc, and provides a dense spatter-free deposit. Corrosion resistance is good, together with good colour match. It is characterised by low amperage application and easy slag removal. Tensile strength is up to 28,000 psi or 193 MPa.
AWS A5.3
79
E4043
WELDWELL
Typical Applications Recommended for use on aluminium plates, sheets and castings. Ideal for tanks, railings, pipe, truck and automotive construction and repairs. Outstanding for repairing cracks, build-up of missing sections, cladding and reinforcing.
Welding Techniques After cleaning weld area it is advisable to preheat to 204o315oC before welding commences. A short-arc should be maintained, tilting the electrode slightly in the direction of travel. Either stringer or weaving technique, as used in welding steel, is suitable except that the rate of welding speed must be considerably greater. As with all aluminium welding, the flux must be removed and this can be done with a wire brush and hot water solution containing 5% nitric or 10% sulphuric acid. Rinse with clean hot water. Can only be used on DC + current.
:
ELECTRODES FOR WELDING ALUMINIUM
Recommended Amperages Dia. Amperes Voltage mm 3.2 85-135 18-22 DC + Storage Store electrodes in a dry place. To recondition moist electrodes bake for one hour at 95oC in a vented oven.
Section Four Miscellaneous
To convert ksi to MPa multiply ksi x 6.895 eg 20 ksi = 137.9 MPa
80
PHYSICAL PROPERTIES OF METALS AND ALLOYS Melting Point deg. C
Coeff. of Expansion x 10 - 6
Thermal Conductivity CGS units
Electrical Resistance Microhms/cm3
659.7 320.9 1890 1495 1083 1063 1535 327.3 651 1260 -38.87 1455 1773.5 960.8 231.9 1800 3370 419.5
2.70 8.64 7.1 8.71 8.96 19.3 7.87 11.34 1.74 7.4 13.55 8.9 21.45 10.5 7.3 4.5 19.3 7.14
23.5 31 6.5 12.5 17.0 14.1 12.1 29.0 26.0 23.0 61 13.3 9.0 19.1 23.5 8.8 4.5 31
0.57 0.20 0.165 0.165 9.94 0.70 0.17 0.082 0.40 0.022 0.21 0.17 1.00 0.155 0.036 0.394 0.265
2.69 7.4 21 6.24 1.673 2.3 9.71 20.6 4.4 160 95.8 6.84 10.6 1.6 12.8 55.0 5.5 5.9
1240-1120 1500-1420 1530-1510 1510-1490 1420-1395 1420-1400 1350-1300 950-925
7.85 7.70 7.92 8.40 8.80 8.53
11.6 13.3 11.4 10.9 18.1 13.9 15.0 19.8
0.148 0.100 0.046 0.05 0.033 0.038 0.06 0.290
55.0 67.0 73.0 108.0 42.5 6.9
1030-850 1042-1040 1050-1000 -577 620-550
8.73 7.6 8.54 2.66 2.63
18.2 17.8 18.0 21.0 24
0.148 0.192 0.112 0.35 0.31
10.5 12.1 26.0 5.4 5.7
Aluminium Cadmium Chromium Cobalt Copper Gold Iron Lead Magnesium Manganese Mercury Nickel Platinum Silver Tin Titanium Tungsten Zinc Cast iron-low Phos 0.5% Carbon Steel 12% Chromium steel 27% Chromium steel 18/8 Cr-Ni stainless 80/20 Ni-Cr Monel Brass 70/30 copper/zinc Bronze 7.5% tin 0.06% Phos. Aluminium Bronze 93/7 Everdur A Aluminium silicon 13% Aluminium magnesium 7%
Density gm/cc
CONVERSION CHART - INCH/MILLIMETRE 1 INCH = 25.399978 MILLIMETRES Inches 1/64 1/32 3/64 1/16 5/64 3/32 7/64 1/8 9/64 5/32 11/64 3/16 13/64 7/32 15/64 1/4
m/m .0156 .0197 .0313 .0394 .0469 .0591 .0625 .0781 .0787 .0938 .0984 .1094 .1181 .125 .1378 .1406 .1563 .1575 .1719 .1772 .1875 .1969 .2031 .2165 .2188 .2344 .2362 .25
.3969 .5 .7937 1 1.1906 1.5 1.5875 1.9844 2 2.3812 2.5 2.7781 3 3.175 3.5 3.5719 3.9687 4 4.3656 4.5 4.7625 5 5.1594 5.5 5.5562 5.9531 6 6.35
Inches 17/64 9/32 19/64 5/16 21/64 11/32 23/64 3/8 25/64 13/32 27/64 7/16 29/64 15/32 31/64 1/2
.2559 .2656 .2756 .2813 .2953 .2969 .3125 .3150 .3281 .3346 .3438 .3543 .3594 .3740 .375 .3906 .3937 .4063 .4134 .4219 .4331 .4375 .4528 .4531 .4688 .4724 .4844 .4921 .5
1 MILLIMETRE = .039370113 INCH m/m
Inches
6.5 6.7469 7 7.1437 7.5 7.5406 7.9375 8 8.3344 8.5 8.7312 9 9.1281 9.5 9.5250 9.9219 10 10.3187 10.5 10.7156 11 11.1125 11.5 11.5094 11.9062 12 12.3031 12.5 12.7
33/64 17/32 35/64 9/16 37/64 19/32 39/64 5/8 41/64 21/32 43/64 11/16 45/64 23/32 47/64 3/4
81
.5118 .5156 .5313 .5315 .5469 .5512 .5625 .5709 .5781 .5906 .5938 .6094 .6102 .625 .6299 .6406 .6496 .6363 .6693 .6719 .6875 .6890 .7031 .7087 .7188 .7283 .7344 .7480 .75
m/m 13 13.0969 13.4937 13.5 13.8906 14 14.2875 14.5 14.6844 15 15.0812 15.4781 15.5 15.875 16 16.2719 16.5 16.6687 17 17.0656 17.4625 17.5 17.8594 18 18.2562 18.5 18.6531 19 19.05
Inches 49/64 25/32 51/64 13/16 53/64 27/32 55/64 7/8 57/64 29/32 59/64 15/16 61/64 31/32 63/64
.7656 .7677 .7813 .7874 .7969 .8071 .8125 .8268 .8281 .8438 .8465 .8594 .8661 .875 .8858 .8906 .9055 .9063 .9219 .9252 .9375 .9449 .9531 .9646 .9688 .9843 .9844 1.0
m/m 19.4469 19.5 19.8437 20 20.2406 20.5 20.6375 21 21.0344 21.4312 21.5 21.8281 22 22.225 22.5 22.6219 23 23.0187 23.4156 23.5 23.8125 24 24.2094 24.5 24.6062 25 25.0031 25.4
WORK, ENERGY: FOOT POUNDS - FORCE TO JOULES Basis: 1 ft = 30.48 cm
ft lbf
0
1 kgf
1
2
3
=
4
980 665 dyn = 107 dyn cm 5
6
7
8
9
joules 20 30 40
27.1164 40.6745 54.2327
28.4722 42.0304 55.5885
29.8280 43.3862 56.9444
31.1838 44.7420 58.3002
32.5396 46.0978 59.6560
33.8954 47.4536 61.0118
35.2513 48.8094 62.3676
36.6071 50.1653 63.7234
37.9629 51.5211 65.0793
39.3187 52.8769 66.4351
50 60 70 80 90
67.7909 81.3491 94.9073 108.465 122.024
69.1467 82.7049 96.2631 109.821 123.379
70.5025 84.0607 97.6189 111.177 124.735
71.8583 85.4165 98.9747 112.533 126.091
73.2142 86.7723 100.331 113.889 127.447
74.5700 88.1282 101.686 115.245 128.803
75.9258 89.4840 103.042 116.600 130.159
77.2816 90.8398 104.398 117.956 131.514
78.6374 92.1956 105.754 119.312 132.870
79.9933 93.5514 107.110 120.668 134.226
100
135.582
136.938
138.293
139.649
141.005
142.361
143.717
145.073
146.428
147.784
STEEL TESTING BY SPARK METHOD Wrought Iron Colour Straw Yellow Average stream length with power grinder 65 in.
Mild Steel Cast Steel Colour - white
Colour - white
Average length of stream with power grinder 70 in.
Average stream length with power grinder - 55 in. Volume - large
Volume-large
Volume moderately large
Long shafts ending in forks and arrowlike appendages
Shafts shorter than wrought iron and in forks and appendages
Colour - White
Forks become more more numerous and sprigs appear as carbon content increases
White Cast Iron Colour - Red Colour straw yellow
High-Carbon Steel
Stainless Steel Alloy Steel Colour straw yellow
Stream length varies with types and amount of alloy content Shafts may end in forks, buds or arrows, frequently with break between shaft and arrow. Few, if any, sprigs
Numerous small and repeating sprigs
Grey Cast Iron
Malleable Iron
Colour - red
Colour straw yellow
Colour straw yellow
Colour - White
Nickel and Monel
Colour - orange
Average stream length with power grinder - 30in
Average stream length with power grinder - 25in
Volume - moderate
Volume - small Average stream length with power grinder - 20 in.
Longer shafts than gray iron ending in numerous small, repeating sprigs
Many sprigs small and repeating Volume - very small
Average stream length with power grinder - 10in Short shafts with no forks or sprigs
Sprigs - finer than gray iron, small and repeating
The Welder is often at a loss to determine the exact quality of a piece of metal, and if a successful weld is to be secured this forehand knowledge is necessary. An easy and useful method is to touch the metal against a high-speed emery wheel and observe the sparks against a black background and compare against the chart. While this is only a guide, practice will assist the operator to select steels by comparison.
82
AWS A2.4.93
AMERICAN WELDING SOCIETY STANDARD WELDING SYMBOLS
83
84
MENSURATION
PARALLELOGRAM
TRAPEZOID
Area = b x h
Area = 1/2 (a + b) x h
TRIANGLE
ELLIPSE
bxh Area = ____ 2
Area = Bab a2 + b2 Circumference = 2Br 2
CIRCLE
SECTOR
Bd 2
11 Area = Br or — (or — x d 2 ) 4 14
Area = Br x o0 or 360
2
Circumference = 2Br =
2
Bd
2
SPHERE
ANNULUS Area = B (r1 + r2) (r1 - r2) (Circles need not be concentric for this rule to apply.)
Area = 4Br 2 = Bd 2 Volume =
CONE
4 3
Br3 =
Bd3 6
CYLINDER
Area of curved surface
Area of curved surface = 2Brh
= Br √ r 2 + h 2
Volume =
sxr
B
Volume = Br 2 h (B = 3•1416 =
r2h
3
85
22 approx) 7
COMPARATIVE HARDNESS SCALES AND WELDWELL ELECTRODE DEPOSIT HARDNESS VPN or DPN Brinell
Pyramid No
Rockwell C
780 755 725 712 699 685 653 627 601 578 555 534 514 495 477 461 444 424 415 401 388 375 363 341 321 302 285 262 248 235 223 212 202 192 187 174 166 156 149 146 143
Approx Tensile N/mm2 B 2640
70 68 67 66 65 64 62 60 58 57 55 53 52 50 49 47 46 45 44 42 41 40 38 36 34 32 30 26 24 22 20 17 15 12 10 7 4 1 -
1150 1080 1000 960 900 885 820 765 717 675 633 598 567 540 515 494 472 456 437 420 404 389 375 350 327 305 287 263 248 235 223 212 202 192 187 174 166 156 149 146 143
Weldwell Electrodes Single layer on M/S
2500 Abrasocord 32
120 119 119 117 117 116 115 115 113 112 112 110 110 109 108 107 105 103 102 99 97 96 94 92 91 88 86 83 81 80 7
2250
PH 700
2000
PH 600 RSP (work hardened)
1500
PH 400
1075 1000 900 870 835 800 760 750 650 630 615 600 585 575 525 510 500
PH 250 RSP as deposited PH 118
PH 56S PH 27 PH C6H PH 46 PH 48A
ARC WELDING LENSES Welding Operation Shielded Metallic Arc (stick)
Electrode Size 2.0 mm 3.2 mm 4.0 mm 5.0 mm
: : : :
Approx Amps Up to 100 100 and over 200 and over 300 and over
2.5 mm 4.0 mm 5.0 mm 6.0 mm
Gas Tungsten Arc (TIG) Non Ferrous Ferrous
Shade Number 9 10 11 12
11 12
Gas metallic Arc (MIG-MAG) Non Ferrous
0.6 mm 0.8 mm : 0.9 mm 1.2 mm : 1.6 mm
9 10 11
Ferrous
0.8 mm 1.2 mm
11 12
: :
0.9 mm 1.6 mm
86
CARE AND STORAGE OF ELECTRODES Air at 15oC and relative humidity 70% will deposit moisture if it is cooled to 10oC. Alternatively, if its temperature is raised to 21oC, its relative humidity falls to 50%. The rate at which equilibrium is reached depends on the degree of porosity of the coating. A relatively impervious coating would seem desirable, but in practice this is not found to be the case. As soon as welding with the electrode is started, the electrode becomes heated by the passage of the welding current and any moisture in the coating is soon converted into steam. If the coating is impervious this vapour cannot escape, and the coating may burst. For example, it is possible for the coating of some electrodes to burst when the moisture content is less than 0.5%; yet others will weld satisfactorily with more than 6% of moisture in the coating. The heating of a coating by passing a current through the electrode is therefore not a good method of judging its moisture content. An impervious coating can be applied to the surface of electrodes after they have been manufactured and dried; to prevent the ingress of moisture, but the materials suitable for this purpose are expensive, and generally produce objectionable fumes during the welding operation. Their use is therefore confined to underwater welding electrodes. In general, basic coated low hydrogen electrodes require protection against the absorption of moisture and are specially packed to ensure that the electrodes will remain factory fresh until opened for use. These remarks on the moisture absorption of electrodes are intended as general guidance only and because there may be exceptions to these rules, it is usually indicated by the manufacturer on the electrode packet label. Damp electrodes are usually indicated by a fierce arc action during welding and an undue amount of spatter. Also the slag is sometimes difficult to remove from the weld bead.
Careless treatment of electrodes, particularly in on-site and outdoor work, can seriously affect the quality of welded joints. It is therefore essential that every welder, storekeeper and foreman should have some elementary knowledge of the correct methods for maintenance and storage. Welders must treat electrodes with the care that every craftsman should take in looking after his materials and tools; for example, no carpenter of repute would leave his chisels to rust in the rain. The coatings of welding electrodes can be damaged by:1. Mechanical force 2. Absorption of moisture 3. Deterioration through age There are other factors which will also produce damaged coatings, but these are rare and beyond the scope of this elementary survey. The three main sources of damage are detailed as follows :Mechanical Force: Coatings are generally robust (except for some low hydrogen types) and can only be damaged by violent handling; by this it is meant treading on them, bending them, or in general treating them roughly. Damage from such treatment is always so obvious that no welder would consider using the electrodes. Moisture Absorption: Too high a percentage of moisture in an electrode can be dangerous, in that it will seriously affect the quality of the weld. In many cases, a welder will not be aware that an electrode is unserviceable, and even if he is, he may not realise the effects of excessive moisture. He may not be able to see the porosity or piping forming in the weld though it can be detected immediately by X-rays. When leaving the manufacturer all electrodes contain a percentage of moisture, the amount has been determined after much research work, and is carefully controlled, but varies with different types of electrodes. The basic electrode E xx 16, E xx 18, E xx 28 class are dried by a special process and contain practically no moisture. Acid or Organic Rutile types, class E xx 12, E xx 13, E xx 27 are less affected by moisture than the basic types and the Cellulosic type E xx 10 and E xx 11 class will absorb a considerable amount of moisture before causing piping or porosity. The equilibrium moisture content of the coating of an electrode varies with the relative humidity of the atmosphere, and it rises rapidly when the relative humidity exceeds 70%. The relative humidity is the percentage of moisture in the air compared with the quantity required to saturate it at the same temperature. The quantity of moisture that the air can hold rises as its temperature rises, so that if there is no change in the total moisture content of the air, the relative humidity falls as the temperature rises, and increases as the temperature falls. When the temperature falls below the point where the relative humidity becomes 100%, moisture is deposited. The temperature at which this happens is known as the dew point temperature. The relative humidity of the air in this country is often of the order of 60 to 80%, and to reduce this to a reasonable value, heating of an electrode store is desirable. The importance of maintaining the heat during the nights and weekends may be illustrated by the following example.
Deterioration through age: Another form of attack which can take place on electrode coatings in storage for long periods produces more obvious results in the form of a white or crystalline fur on the surface of the coating. This fur is produced by a chemical reaction between the carbon dioxide in the atmosphere and the sodium silicate of the binder, producing crystals of sodium carbonate and silica powder. The rate of reaction appears to be extremely slow in the absence of water and is favoured by conditions of fluctuating humidity. When moisture is deposited, sodium carbonate and silica will be formed and as the reaction is irreversible under these conditions, will remain. Further additions to the deposit will be made every time moisture is deposited. Conditions favouring such deposition can occur in a store or workshop that is heated during working hours but allowed to cool excessively during the night or weekend. The crystals formed do not appear to have any serious effect on the welding quality of most electrodes, but their presence in excess may lead to the disruption of the coating as a result of rusting of the core wire. Their presence may, however, be taken as an indication of old electrodes and unsatisfactory storage conditions.
87
RECOMMENDATIONS FOR STORAGE AND DRYING OF ELECTRODES.
Storage: For bulk storage of unopened electrodes, the temperature of the storage room should be maintained at not less than 20oC. If the humidity in the room does not exceed 50% the electrodes should be maintained in a suitable condition. When stored in this manner, electrodes may be used direct from a previously unopened packet. This includes low hydrogen types, however, more specific storage is then required for low hydrogen electrodes (see below). Once the electrode packet has been opened, unused electrodes should be stored in a heated, but ventilated cabinet, on perforated shelves. The temperature should be maintained at a minimum of 20oC or at least 10oC above ambient. The electrodes should not be over-stacked, thus restricting ventilation.
Storage for Low Hydrogen Electrodes: For highest weld quality and to obtain specific low hydrogen weld metal levels low hydrogen electrodes should be baked before use (see individual data sheets). For intermediate storage (after baking, but before being used on site) the electrodes should be stored in a holding oven at 120-150oC. Electrodes can be held in the holding oven for a maximum period of six weeks. For site welding the electrodes should be held in a hot box at a minimum temperature of 70oC, for no more than eight hours. Unused electrodes should be returned to the holding oven.
Re-Drying: When re-drying it is advisable to bring the oven up gradually to the required temperature. Placing damp electrodes in an already hot oven may cause cracking of the flux coating. Rutile Electrodes: ie Weldwell PH 28, 46, 48A, 68, 78, C18, WIA Austarc 12P. - Rutile type electrodes require a small amount of moisture for best running characteristics. Therefore it is essential that this small amount of moisture is not dried out when drying these types. If electrodes become damp, re-dry at 120oC for 30 minutes. It will be necessary to test weld the electrodes running characteristics to ensure no other drying takes place. Cellulose Electrodes ie Weldwell PH 31A, Pipemaster 60, Pipemaster 70. These electrodes require a fairly high percentage of moisture for optimum running characteristics, and if dried will lose arc voltage. Redrying is not recommended for these electrode types. Iron Powder Electrodes ie Weldwell PH 22, 7024 As with rutile types, iron powder electrodes require a small amount of moisture for best running characteristics, but the re-drying temperatures are much higher. If electrodes become damp re-dry at 250oC for 30 minutes. Low Hydrogen Electrodes ie Weldwell PH 27, 27P, 56S, 56R, 75, 77, C6H, 118, KV range, WIA Austarc 16TC. If electrodes become damp they must be re-dried for one hour at the recommended temperatures (two hours for Austarc 16TC). These temperatures can also be used to obtain low or very low weld metal hydrogen levels (refer to individual data sheets). Do not stack more than four layers deep. Stainless Steel electrodes ie Weldwell PH RS308LC, RM318LC, BM310, RM316LC, RS309LC, RS309MoLC, 22.9.3LR, 22.12HTR, WIA Staincord 316L-16. Stainless steel electrodes also require re-drying if they become damp. Re-dry for one hour at 350oC except BM310 which should be re-dried for one hour at 280oC and Staincord 316L-16 which should be redried for two hours at 200oC. Do not re-dry more than five times otherwise flux deterioration could occur.
88
ELECTRODES AGENCY APPROVAL GRADES Electrodes
Lloyds Register of Shipping
American Bureau of Shipping
Bureau Veritas
PH 28
2
2
2
PH 31A
3
3
3
PH 46
2
2
2
PH 48A PH 68
2, 2Y
2
1
PH 78
1
1
3
3
PH C18
2
2
2
PH 7024
2, 2Y
2
2
PH 27
3, 3YH15
3H5, 3Y
3, 3Y HH
PH 27P
3, 3YH5
3H5, 3Y
3, 3YHH
PH 22
2, 2Y
2, 2Y
PH 56S
3, 4YH5
3H5, 3Y
3, 3YHH
PH 75
5Y40H10
3H10, 3Y
3, 3YHH
PH 77
3, 4YH5
3H5, 3Y
3HH
PH C6H
3, 3YH5
3H5, 3Y
3, 3YHH
PH 118
E11018-G
PH KV3
E8015-B3L
PH KV5
E7015-B2L
PH RS308LC
E308L-17
PH RM316LC
E316L-17
PH RS309MoLC
E309MoL-17
PH22-9-3LR Austarc 12P Austarc 16TC
Det Norske Veritas
E2209-16 2, 2Y
2
2
3, 4YH10
3H10
3YH10
89
TYPE
MM
APPROX RODS PER PKT
KG
PH 28
2.5 3.2 4.0 5.0
159 164 104 53
2.5 5 5 5
Austarc 12P
2.0 2.5 3.2 4.0 5.0
250 160 159 105 56
2.5 2.5 5 5 5
PH 45E
4.0
94
5
PH 46
2.0 2.5 3.2 4.0
201 144 142 80
2.5 2.5 5 5
2.5 3.2 4.0
158 158 105
2.5 5 5
2.5 3.2 4.0 5.0
172 163 109 72
2.5 5 5 5
2.5 3.2 4.0
148 148 99
2.5 5 5
PH C18
3.2 4.0
126 85
5 5
PH 22
3.2 4.0
90 52
5 5
PH 7024
2.5 3.2 4.0 5.0
97 91 54 32
2.5 5 5 5
2.5 3.2 4.0 5.0
166 166 107 73
2.5 5 5 5
PH 48A
PH 68
PH 78
PH 31A
Pipemaster 60
Pipemaster 70
2.4 3.2 4.0 4.8
1500 850 600 400
3.2 4.0 4.8
850 600 400
TYPE
MM
APPROX RODS PER PKT
KG
PH 27
3.2 4.0 5.0
148 103 55
5 5 5
PH 27P
2.5 3.2 4.0
129 90 60
2.2 5.0 5.0
Austarc 16TC
2.5 3.2 4.0 5.0 6.0
147 148 90 49 35
2.5 5 5 5 5
PH 56S
2.5 3.2 4.0 5.0 6.0
131 151 99 56 38
2.2 5 5 5 5
PH 56R
5.0
55
5
PH 75
3.2 4.0
138 95
5 5
PH 77
2.5 3.2 4.0 5.0
107 126 87 47
2.2 5 5 5
3.2 4.0 5.0 6.0
75 42 28 20
5 5 5 5
PH 118
3.2 4.0 5.0
122 86 45
5 5 5
PH KV3
2.5 3.2 4.0
115 131 91
2.2 5 5
PH RS308LC
2.5 3.2 4.0
143 77 50
2.5 2.5 2.5
PH BM310
2.5 3.2 4.0
140 72 48
2.5 2.5 2.5
PH C6H
22.7 PH RM316LC 22.7
141 76 51
2.5 3.2 4.0
90
2.5 2.5 2.5
TYPE
MM
APPROX RODS PER PKT
KG
PH RM318LC
2.0 2.5 3.2 4.0
228 138 78 50
2.5 2.5 2.5 2.5
Austarc Staincord 316L-16
2.0 2.5 3.2 4.0
210 137 71 47
2.5 2.5 2.5 2.5
PH RS309LC
2.5 3.2 4.0
130 78 51
2.5 2.5 2.5
PH RS309MoLC
2.5 3.2 4.0
118 76 50
2.5 2.5 2.5
PH 22.9.3LR
2.5 3.2 4.0
139 81 55
2.5 2.5 2.5
ELITE RSP
2.5 3.2 4.0
143 78 51
2.5 2.5 2.5
ELITE HI TEN 8
2.5 3.2 4.0
151 74 51
2.5 2.5 2.5
Austarc C&G
3.2 4.0
83 69
4 4
Supercast Ni
2.5 3.2 4.0
154 83 56
2.5 2.5 2.5
Supercast NiFe
3.2 4.0
89 57
2.5 2.5
PH MN
4.0
78
5
PH 250
3.2 4.0
126 68
5 5
PH 400
3.2 4.0 5.0
127 68 46
5 5 5
PH 600
3.2 4.0 5.0
133 67 45
5 5 5
PH 700
3.2 4.0 5.0
86 57 36
5 5
Abrasocord 43
3.2 4.0
87 56
5 5
WELD DEPOSITION AND COSTING DATA Dimension the shapes, from available information, by calculation or by "intelligent guessing". Using these dimensions, the mass of weld metal per metre of joint can be arrived at for each shape segment using the data from Tables 1.0-1.4. From here, the total mass of weld metal required per metre of joint can be simply calculated by adding the figures obtained for each shape segment. Practical Example 1 For the U-joint illustrated in Figure 10, assume the following dimensions. T (plate thickness) = 60 mm = 100 (therefore, included angle is 20o) r (root radius) = 10 mm = 8 mm d2 (root face) Side A Rectangular, Triangular and Radius Cross-Sections With a root face (d2) of 8 mm and a root radius (r) of 10 mm, the depth of the rectangular and triangular sections (d) will be, d = T, - (d2 + r) = 60 - 18 = 42 mm. The width of the rectangle (w) is of course equal to 2r - 20 mm. From Table 1.0, the mass of weld metal per metre of joint required for a rectangle of area, 20 x 42 mm = 840 mm2, is approximately ........................... 6.59 kg/m (A) From Table 1.1, two triangles with an included angle of 200 and a depth of 42 mm will need a mass of weld metal per metre of joint of approximately ........................... 2.50 kg/m (B) From Table 1.3, a semi-circular section of radius 10 mm will require a mass of weld metal per metre of joint of approximately
FIGURE 10 Tables 1.0 - 1.5 of this section are a convenient means of determining the mass of weld metal per unit length of joint for each of the simple joint cross-sections described. Simply look up the appropriate dimensions of the shape in question, and the weld metal mass, in kilograms per metre (kg/m), is calculated for you. By referring to GUIDE 1, shown in the following pages, a practical example is given illustrating the correct usage of tables 1.0 - 1.5. Where ready made Tables are not available or greater accuracy is required, the weld cross-section may be drawn on graph paper to a suitable scale; millimetres being ideal. By converting the curves to stepped straight lines and counting the small triangles and squares enclosed by the profile, the cross-sectional area can be accurately determined. Given the length of the required weld, the volume of weld metal can be calculated and converted to the mass of weld metal, using an appropriate density figure. For example, 1 mm2 cross-sectional area of steel weld metal by 1000 mm (1 metre) long has a mass of .00785 kg. Therefore, finding the cross-sectional area, in mm2, and multiplying by .00785 will give the mass of weld metal per metre of joint, in kg/m.
Side A Reinforcement Cross-Section The reinforcement width of Side A (fA) will be the addition of 2r (20 mm) and L (15 mm, taken from Table 1.1) plus whatever overlap onto the parent metal is considered desirable practice. For this example, assume an average overlap of 3 mm on each side of the joint which gives fA = 6 + 20 + 15 = 41 mm. Also let us assume a reinforcement height on Side A (hA) of 3 mm. From Table 1.2, the mass of weld metal required per metre of joint for the reinforcement section of Side A of f = 41 mm and h = 3 mm is approximately 0.75 kg/m (C1) Side B Back Gouged Cross-Section Here the user will be guided by such factors as, the welding process used for the root pass, to determine resultant root penetration, the fracture toughness requirements of the root and established workshop practices, etc, to determine the extent of back gouging required. For this example, we will assume a carbon-arc gouge carried out with a 10 mm carbon to produce a groove 14 mm wide and 10 mm deep. From Table 1.4, the mass of weld metal required per metre of joint to fill a groove of these dimensions is approximately 0.86 kg/m (E) Side B Reinforcement Cross-Section With a gouge width of 14 mm (allow a little more for uneven gouging) and estimating a 3 mm overlap onto each side of the
GUIDE 1 - A GUIDE TO USING TABLES 1.0 - 1.5 (a) FILLET WELDS For fillet welds the user is directed to Table 1.5. Select the desired leg length (L) with the likely degree of convexity (h) given the electrode size/type used, the welding position and process etc, and read off the mass of weld metal per metre of joint (kg/m). For acute angle or obtuse angle fillets or fillets of unequal leg length, treat as for a butt weld and refer to (b). (b) BUTT WELDS For butt welds, first sketch the joint cross-section under consideration, breaking it down into fundamental shapes such as rectangles, triangles and reinforcement and radius sections as shown in Figure 10.
joint gives a reinforcement width for Side B (fB) of 21 mm. From Table 1.2, the mass of weld metal required per metre of joint for a reinforcement section of f = 21 mm and an assumed height of h = 1.5 mm is approximately ....... 0.19 kg/m (C2) Therefore, A + B + D + C1 + E + C2 gives the total mass of weld metal required per metre of joint 6.59 + 2.50 + 1.23 + 0.75 + 0.86 + 0.19 = 12.12 kg/m.
91
WELD DEPOSITION AND COSTING DATA (contd) Mass of Weld Metal in Joint Table 1.0 RECTANGULAR WELD CROSS-SECTIONS
This table provides the mass of steel weld metal per metre of joint (kg/m) for known cross-sectional areas. Simply, multiply “d” x “w” for cross-sectional area (mm2) and read directly from the table. Where a sectional or total joint area is already known in square inches, multiply by 645.2 for mm2 and use this table.
Area (mm2)
0
10
20
30
40
50
60
70
80
90
0
-
0.08
0.16
0.24
0.31
0.39
0.47
0.55
0.63
0.71
100
0.79
0.86
0.94
1.02
1.10
1.18
1.26
1.33
1.41
1.49
200
1.57
1.65
1.73
1.81
1.88
1.96
2.04
2.12
2.20
2.28
300
2.36
2.43
2.51
2.59
2.67
2.75
2.83
2.90
2.98
3.06
400
3.14
3.22
3.30
3.38
3.45
3.53
3.61
3.69
3.77
3.85
500
3.93
4.00
4.08
4.16
4.24
4.32
4.40
4.47
4.55
4.63
600
4.71
4.79
4.87
4.95
5.02
5.10
5.18
5.26
5.34
5.42
700
5.50
5.57
5.65
5.73
5.81
5.89
5.97
6.04
6.12
6.20
800
6.28
6.36
6.44
6.52
6.59
6.67
6.75
6.83
6.91
6.99
900
7.07
7.14
7.22
7.30
7.38
7.46
7.54
7.61
7.69
7.77
1000
7.85
7.93
8.01
8.09
8.16
8.24
8.32
8.40
8.48
8.56
Where increments of less than 10mm2 are considered necessary, add to the above, on the basis of .008 kg/m for every 1 mm2.
92
WELD DEPOSITION AND COSTING DATA (contd) Mass of Weld Metal in Joint Table 1.1 TRIANGULAR WELD CROSS SECTIONS
Table 1.TRIANGULAR WELD CROSS SECTIONS Contd
Table 1.TRIANGULAR WELD CROSS SECTIONS
Mass of Steel Weld Metal per Metre of Joint (kg/m)
Mass of Steel Weld Metal per Metre of Joint (kg/m)
Depth Width d L (mm) (mm)
Depth Width d L (mm) (mm)
kg/m
Width L (mm)
kg/m
Width L (mm)
kg/m
Width L (mm)
kg/m
kg/m
Width L (mm)
kg/m
Width L (mm)
kg/m
Width L (mm)
kg/m
6
3.5
0.08
6.0
0.14
2.1
0.05
3.2
0.08
6
5.6
0.13
6.9
0.16
8.4
0.20 12.0
0.28
8
4.6
0.14
8.0
0.25
2.8
0.09
4.3
0.14
8
7.5
0.24
9.2
0.29 11.2
0.35 16.0
0.50
10
5.8
0.23
10.0
0.39
3.5
0.14
5.4
0.21
10
9.3
0.37
11.5
0.45 14.0
0.55 20.0
0.79
12
6.9
0.32
12.0
0.57
4.2
0.20
6.4
0.30
12
11.2
0.53
13.9
0.65 16.8
0.79 24.0
1.13
14
8.1
0.45
14.0
0.77
4.9
0.27
7.5
0.41
14
13.1
0.72
16.2
0.89 19.6
1.08 28.0
1.54
16
9.2
0.58
16.0
1.00
5.6
0.35
8.6
0.54
16
14.9
0.94
18.5
1.16 22.4
1.41 32.0
2.01
18
10.4
0.73
18.0
1.27
6.3
0.45
9.6
0.68
18
16.8
1.19
20.8
1.47 25.2
1.78 36.0
2.54
20
11.5
0.90
20.0
1.57
7.1
0.56 10.7
0.84
20
18.7
1.47
23.1
1.81 28.0
2.20 40.0
3.14
22
12.7
1.10
22.0
1.90
7.8
0.67 11.8
1.02
22
20.5
1.77
25.4
2.19 30.8
2.66 44.0
3.80
24
13.9
1.31
24.0
2.26
8.5
0.80 12.9
1.22
24
22.4
2.11
27.7
2.61 33.6
3.17 48.0
4.52
26
15.0
1.53
26.0
2.65
9.2
0.94 13.9
1.42
26
24.2
2.47
30.0
3.06 36.4
3.71 52.0
5.31
28
16.2
1.78
28.0
3.08
9.9
1.09 15.0
1.65
28
26.1
2.87
32.3
3.55 39.2
4.31 56.0
6.15
30
17.3
2.04
30.0
3.53 10.6
1.25 16.1
1.90
30
28.0
3.30
34.6
4.07 42.0
4.95 60.0
7.07
35
20.2
2.77
35.0
4.81 12.3
1.69 18.8
2.58
35
32.6
4.48
40.4
5.55 49.0
6.73 70.0
9.62
40
23.1
3.63
40.0
6.28 14.1
2.21 21.4
3.36
40
37.3
5.86
46.2
7.25 56.0
8.79 80.0
12.56
45
26.0
4.59
45.0
7.95 15.9
2.81 24.1
4.26
45
42.0
7.42
52.0
9.18 63.0
11.13 90.0
15.90
50
28.9
5.67
50.0
9.81 17.6
3.45 26.8
5.26
50
46.6
9.15
57.7
11.32 70.0
13.74 100.0 19.63
55
31.8
6.86
55.0
11.87 19.4
4.19 29.5
6.37
55
51.3
11.07
63.5
13.71 77.0
16.62 110.0 23.75
60
34.6
8.15
60.0
14.13 21.2
4.99 32.2
7.58
60
56.0
13.19
69.3
16.32 84.0
19.78 120.0 28.26
65
37.5
9.57
65.0
16.58 22.9
5.84 34.8
8.88
65
60.6
15.46
75.1
19.16 91.0
23.22 130.0 33.17
70
40.4
11.10
70.0
19.23 24.7
6.79 37.5
10.30
70
65.3
17.94
80.8
22.20 98.0
26.93 140.0 38.47
75
43.3
12.75
75.0
22.08 26.4
7.77 40.2
11.83
75
69.9
20.58
86.6
25.49 105.0 30.91 150.0 44.16
80
46.2
14.51
80.0
25.12 28.2
8.85 42.9
13.47
80
74.6
23.42
92.4
29.01 112.0 35.17 160.0 50.24
93
WELD DEPOSITION AND COSTING DATA (contd) Mass of Weld Metal in Joint Table 1.2 WELD REINFORCEMENT CROSS-SECTIONS
Table 1.3 RADIUS WELD CROSS-SECTIONS Radius , r (mm)
Face Width (f) (mm)
Mass of Weld Metal per Metre of Reinforcement (kg/m)
REINFORCEMENT HEIGHT, H h = 1.0 mm
h = 1.5 mm
h = 3.0 mm
h = 4.5 mm
h = 6.0 mm
Mass of Weld Metal Per Metre of Joint (kg/m) "U"
"J"
3
0.11
0.06
4
0.20
0.10
5
0.31
0.15
6
0.44
0.22
7
0.60
0.30
8
0.79
0.39
9
1.00
0.50
10
1.23
0.62
11
1.49
0.75
12
1.78
0.89
6
0.04
0.06
13
2.08
1.04
8
0.05
0.07
14
2.42
1.21
15
2.77
1.39
10
0.06
0.09
0.18
0.28
12
0.07
0.11
0.22
0.33
14
0.09
0.13
0.26
0.39
16
0.10
0.15
0.30
0.44
18
0.11
0.17
0.33
0.50
0.67
20
0.12
0.18
0.37
0.55
0.74
22
0.14
0.20
0.41
0.61
0.81
24
0.15
0.22
0.44
0.67
0.89
26
0.16
0.24
0.48
0.72
0.96
28
0.17
0.26
0.52
0.78
1.04
Table 1.4 BACK GOUGED WELD CROSS-SECTIONS Depth Width Area (mm) (mm) (mm2)
Mass of Weld Metal per Metre of Joint (kg/m)
1.5
6
7.07
0.06
2.5
8
15.71
0.12
3.5
7
19.24
0.15
4
12
37.70
0.30
39.27
0.31
30
0.18
0.28
0.55
0.83
1.11
5
10
35
0.22
0.32
0.65
0.97
1.29
7
12
65.97
0.52
8
19
119.38
0.94
40
0.25
0.37
0.74
1.11
1.48
10
14
109.96
0.86
45
0.28
0.42
0.83
1.25
1.66
10
22
172.79
1.36
50
0.31
0.46
0.92
1.39
1.85
12
20
188.50
1.48
15
30
353.43
2.77
Note: For face widths in excess of 50 mm, estimate average height of reinforcement and calculate as for a rectangle, referring to Table 1.0
94
Note: Appropriate reinforcement additions, selected from Table 1.2, will generally be required to be added to the above figures.
WELD DEPOSITION AND COSTING DATA (contd) Mass of Weld Metal in Joint Table 1.5 FILLET WELDS The table shows the mass of steel weld metal per metre of joint (kg/m) for fillet welds of varying degrees of convexity and a typical concave profile. The figures are based on actual leg length being maintained. Note that the leg lengths shown are not applicable to the concave welds which are designated in this table by throat thickness. Note: For Aluminium weld metal divide the steel weld metal mass per metre by 2.9. Weld Size Leg Length, L (mm) 3.2 3.5 4.0 4.8 5.0 5.6 6.0 6.4 7.0 8.0 9.5 10.0 12.7 15.9 19.0 22.2 25.4
(inch) 1/8 5/32 3/16 7/32 1/4 ~5/16 3/8 1/2 5/8 ~3/4 7/8 1.0
MASS OF WELD METAL PER METRE (kg/m) Throat Thickness T (mm) 2.3 2.5 2.8 3.4 3.5 4.0 4.2 4.5 4.9 5.7 6.7 7.1 9.0 11.2 13.4 15.7 18.0
Crosssectional Area (mm2)
Flat and Convex Welds h=0 (Theor.)
5.1 6.1 8.0 11.5 12.5 15.7 18.0 20.5 24.5 32.0 45.1 50.0 80.6 126.4 180.5 246.4 322.6
h= 1.0 mm
.04 .05 .06 .09 .10 .12 .14 .16 .19 .25 .36 .39 .63 .99 1.42 1.93 2.53
.07 .08 .09 .13 .14 .17 .19 .22 .25 .32 .44 .48 .74 1.13 1.59 2.13 2.75
h= 1.5 mm .08 .10 .11 .15 .17 .19 .22 .24 .28 .35 .48 .52 .80 1.20 1.67 2.23 2.86
h= 2.5 mm .57 .61 .91 1.34 1.84 2.42 3.08
Concave Welds Typical Throat Thickness Concave Weld T (mm) 2.3 0.05 2.5 0.06 2.8 0.07 3.4 0.10 3.5 0.11 4.0 0.13 4.2 0.15 4.5 0.17 4.9 0.21 5.7 0.27 6.7 0.39 7.1 0.42 9.0 0.68 11.2 1.06 13.4 1.52 15.7 2.06 18.0 2.70
Quantity of Consumables Required Given the mass of weld metal required to "fill" a metre of joint, the next step is to determine the mass of consumable(s) required. The weld metal yield achieved from welding with a consumable electrode largely depends on the efficiency of the welding process and the consumable in question. The "QUANTITY OF CONSUMABLE" figures listed in Table 2.0 are for a weld metal yield of 1 kg and take into CONSUMABLE TYPE account inherent wastage losses such as weld metal spatter, slag coverage, stub ends, etc. An additional High Efficiency (150%), Iron Powder Type percentage (listed in the "EXTRA FOR Electrodes WASTAGE" column) is usually added to PH 22, PH 7024 allow for typical shop wastage. TO OBTAIN THE QUANTITY OF CONSUMABLE REQUIRED TO YIELD 1 KG OF WELD METAL READ DIRECTLY FROM TABLE 2.0 FOR THE APPROPRIATE ELECTRODE.
QUANTITY OF CONSUMABLE
ELECTROD E LENGTH (MM)
50mm STUB LENGTH
75mm STUB LENGTH
455 380
1.62 1.63
1.68 1.75
10% 10%
Conventional, Low Iron Powder or BasicHydrogen Controlled Electrodes PH 28, PH 48A, PH 77, PH 56S, PH C18
455 380
1.65 1.66
1.75 1.77
10% 10%
Cellulose Type Electrodes PH 31A, Pipemaster 60
380
1.73
1.87
10%
Table 2.0 Manual Metal-Arc Welding (MMAW)
95
EXTRA FOR WASTAGE
WELD DEPOSITION AND COSTING DATA (contd) Electrode Consumption for some Common Butt Joints The following tables provide useful data on the mass of weld metal and MMAW electrodes required to complete some common butt joints. Electrode consumption is calculated using the following simple equation: M= where M D P**
= = =
________ D 1 - P Mass of electrodes required per metre of joint Mass of weld metal deposited per metre of joint. Proportion of electrode lost, due to spatter, slag loss, stub end etc.
Square Groove Butt Joint - welded both sides reinforcement height, r = 2 mm
W
Mass of steel weld metal deposited per metre (D) (kg/m)
Mass of MMAW** electrodes required per metre (M) (kg/m)
7 7 10 10
0.17 0.20 0.32 0.39
0.28 0.33 0.53 0.64
Mass of MMAW** electrodes required per metre (M) (kg/m)
Joint Dimensions T
R 0 1 1.5 3
3 3 6 6
Single-V Butt Joints reinforcement height, r = 2 mm
Joint Dimensions T 6 8 10 12 16 20
R
L
W
Mass of steel weld metal deposited per metre (D) (kg/m)
3.5 3.5 3.5 3.0 3.0 3.0
1.5 1.5 1.5 3.0 3.0 3.0
10.0 13.0 15.0 15.0 19.0 23.0
0.26 0.57 0.79 0.83 1.38 2.06
0.43 0.95 1.31 1.39 2.29 3.43
Mass of MMAW** electrodes required per metre (M) (kg/m) 1.18 1.75 2.48 3.53 11.58
Double-V Butt Joints reinforcement height, r = 2 mm Joint Dimensions T 12 16 20 25 50
R
L
W
Mass of steel weld metal deposited per metre (D) (kg/m)
3.0 3.0 3.0 3.0 3.0
3.0 3.0 3.0 3.0 3.0
10.0 12.0 15.0 18.0 32.0
0.71 1.06 1.50 2.13 6.97
** For 380 mm long EXX12, 13, 14, 16 & 18 type MMAW electrodes to AS 1553.1, P is typically 0.4. This figure assumes a stub end length of 50 mm (See Table 2.0 for further details.) 96
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McDONALD EQUIPMENT LTD 362 Heads Road PO Box 673 Ph: (06) 344 4804 Fax (06) 344 4112
WESTPORT
BULLER HYDRAULICS Nelson Street PO Box 175 Ph: (03) 789 5181 Fax (03) 789 5071