Failure Analysis of Plug of Valve Investment Casting at Creative Castings Limited- Junagadh

IJSRD - International Journal for Scientific Research & Development| Vol. 4, Issue 05, 2016 | ISSN (online): 2321-0613

Failure Analysis of Plug of Valve Investment Casting At Creative Castings Limited- Junagadh Prof. Kalpesh D. Parmar1 Mr. Kartik Sardhara2 Mr. Rushikesh Pithiya3 Abstract— There are various defects and in Investment casting. In this project our attempt is to find out various defects occurs in Investment casting process at Creative Castings Limited. We are going to analyze periodic defects like porosity, inclusions, shrinkage in investment casting and try to reduce these defects by some remedial procedures. We have also analyzed the various failures like inclusion, porosity, shrinkage in ANSYS & E-foundry analysis software and optimization.

Key words: ANSYS & E-foundry analysis software and optimization

In the creative casting Pvt. Ltd. They have many products are occurs many defects.

So, here we will select the product which have maximum defect of inclusion.

I. INTRODUCTION Investment casting is often called “lost wax” casting, and it is based on one of the oldest metal forming processes.

The Egyptians used the process, some 5000 years ago, to make gold jewellery, as exact replica of many intricate shapes, cast in gold from artfully created beeswax patterns.

In the investment casting process, ceramic slurry is applied, or “invested “around a disposable pattern, usually wax, and is allowed to harden to form a disposable casting mold. The wax pattern is “lost”, when it is melted out from the “disposable “ceramic mold, which is later destroyed to recover the casting.

In investment casting, the ceramic molds are made by two different methods: the solid mold process and the ceramic shell process. The solid mold process is mainly used for dental and jewelry castings, currently has only a small role in engineering applications, and as such will not be covered in this chapter. The ceramic shell process has become the predominant technique for a majority of engineering applications, displacing the solid mold process.

The ceramic shell process is precision casting process, uniquely developed adopted to produce complex shape casting to near net shape and numerous alloys.

Continued advancements in materials and techniques used in the process, are driven and supported by R&D on many fronts, both in the industry as well as in many schools for foundry metallurgy. For instance, earlier research, funded

by Rolls Royce Limited, UK, at the University of Birmingham, UK, investigating the feeding behavior of high temperature Alloys has assisted in the development of optimal gating and feeding systems for investment castings A. Types of Casting 1) Investment casting 2) Sand casting 3) Permanent mold casting 4) Centrifugal casting 5) Form casting 6) Expandable mold casting II. DATA COLLECTION In the casting industries the inclusion is the major defect so we discuss that defect according to industrial components.

Fig. 1: Plug for Valve A. Specification of Plug Product               

Die no.:-4572 Product name: - plug 2” Weight of product: - 1.20kg Material: - 904L cast iron Heat no. : - k59 Batch quantity: - 32 Wax temperature:-55 C Dwell time:-2.5 min Cycle time: - 5 min Pattern per shall: - 4 Ingrate size and quantity: - 1” × 1” – 1 gate, 1” × 1 ½” – 2 gate Runner bar size: - 1 ½‟ × 2‟ × 10‟ Wax pattern weight:- 0.2 kg Assembly weight: - 1.5 kg

B. Melting    

Shell firing temperature: - 900 Heat no. : - 7292 s Metal bath temperature: - 1550-1620 Ladle temperature:-1500-1570

C. Final Inspection     

Total no. of quantity: - 32 Inclusion: - 5 Porosity: - 1 Shrinkage: - 1 Ok piece: - 25

D. Different Types of Investment Casting Defects    

Fins Swells Blowholes/pinholes Shrinkage Porosity

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Failure Analysis of Plug of Valve Investment Casting At Creative Castings Limited- Junagadh (IJSRD/Vol. 4/Issue 05/2016/022)

 

Hot tear, hot crack Inclusions

III. DATA COLLECTION INCLUSIONS: “THE MAJOR DEFECTS IN INVESTMENT CASTING” The ever increasing demand for high quality has made the steel maker increasingly aware of product cleanliness requirements. Foreign particles which will not dissolve in liquid metal cause inclusion. Foreign particles which were introduced from outside, for example particles of investment. Inclusions formed by reaction with alloy elements, for example oxides and sulphides of copper and silver.

Sharp corners or bends in sprueing Inclusion defects of castings are defects such as slag of oxides and other substances generated in the ladle by the reaction and sand of moulds and the cores that flake away and are included in molten metal, flowing into products and appearing on the surfaces of parts as non-metallic inclusions.

These defects are inflicted by chips during machining and by other causes. The attachment process of an inclusion to a gas bubble in the molten steel proceeds through the following steps. The inclusion approaches the gas bubble, and collides if it gets close enough. If the thin film of liquid between the particle and the bubble decreases to less than a critical thickness, it will suddenly rupture causing the inclusion to attach permanently to the surface of the bubble during the collision. Otherwise, if it slides along the surface of the bubble for a long enough time, the thin film can drain away and rupture, again leading to inclusion attachment.

Fig. 2: Analysis of Annual Production of Plug VI. POSSIBLE SOLUTION OF INVESTMENT CASTING DEFECTS    



To change the assembly design of the pattern like change in gate position, no. of gate, Dimension of gate etc.

Change in the pouring temperature can reduce the inclusion and many defect.

Decrease the pouring time.

Replace crucible.

The most common type of crucible used in induction melting are Graphite Serious problems can occur if the graphite breaks down to powder form and Is poured into the mould with the metal. The main problem therefore, is graphite.

Inclusions which show themselves as small black deposits that form at the tree base.

VII. MODELING IN SOLID WORKS & ANALYSIS IN ANSYS SOFTWARE

IV. POSSIBLE SOLUTION OF INVESTMENT CASTING DEFECTS    

To change the assembly design of the pattern like change in gate position, no. of gate, Dimension of gate etc.

Change in the pouring temperature can reduce the inclusion and many defect.

Decrease the pouring time.

Replace crucible. The most common type of crucible used in induction melting are Graphite Serious problems can occur if the V. ANALYSIS OF ANNUAL DATA

Month Total Produc t Reject Produc t

Ja n

Fe b

Ma r

Ap r

Ma y

Ju n

Jul y

Au g

Se p

11

9

12

5

20

7

8

11

13

2

-

1

1

5

2

1

2

2

Fig. 3: Modelling of Plug in solid works

Table 1: Annul Data of Production in (2015)

Fig. 4: Steady state thermal Analysis

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Failure Analysis of Plug of Valve Investment Casting At Creative Castings Limited- Junagadh (IJSRD/Vol. 4/Issue 05/2016/022)

,Accepted –Prihvaćeno,2014-09-10 Professional Paper – Strukovnirad.

[5] Vipul vasava, dhaval joshi: “Simulation of shrinkage defect”, “International journal of engineering trends and technology volume 4 issue 6” June 2013.

[6] http://efoundry.iitb.ac.in [7] https://en.m.wikipedia.org/wiki/investment_casting [8] https://patents.google.com [9] https://www.creative-cast.com [10] Foundry technology by O. P. Khanna.

Fig. 5: Heat flux Analysis

Fig. 6: Analysis for temperature distribution VIII. CONCLUSION From the above analysis it is found that most of plug failure in casting is due to inclusion defect and to rectify the problem proposed solution is to change the assembly design of the pattern assembly like change in, gate position, No. of gate, Dimension of gate etc REFERENCES [1] Binu Bose V, K N Anilkumar,“Reducing rejection rate of castings using Simulation Model”, “International Journal of Innovative Research in Science, Engineering and Technology, Volume 2, Special Issue 1”,December 2013.

[2] Rajesh Rajkolhe, J. G. Khan Asst Professor,“Defects, Causes and Their Remedies in Casting Process” Mechanical Engineering Department, Shri Sant Gajanan Maharaj College of Engineering, Shegaon. International Journal of Research in Advent Technology, Vol.2, No.3, March 2014.

[3] Vipul vasava, dhaval joshi,“Simulation of shrinkage defect”, “International journal of engineering trends and technology volume 4 issue 6” June 2013.

[4] S. Rzadkosz, J. Zych, A. Garbacz-Klempka, M. Kranc, J. Kozna, M. Pieos, J. Kolczyk, L. Jamrozowicz, T. Stolarczyk,“Copper Alloys in investment Casting Technology Received – Prispjelo: 2014-04-29

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