Corrosion & Materials December 2011

Official

Publication

& Vol 36 No 6, December 2011 ISSN 1326-1932

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Inside this Issue: University Profile: Deakin University Project Profile: Cathodic Protection of a 1.2km long Harbour Tunnel Technical Note: Copper Based Antifouling Coatings on Aluminium Hulls Technical Note: Effect of Surface Roughness on the Corrosion of 316-type Stainless Steel Research Paper: Shedding light on Corrosion Research Paper: Underprotection of Mild Steel in Seawater, the Calcareous Film

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Xtroll and Xtroll Global Over 25 years ago Ian Ashworth made his first product simply called Xtroll. Approximately 5 years later with more products being developed the name Xtroll was converted into a trademark for use on all his products. Xtroll Global was established in August 2000 to manufacture and market a range of products under the trademark Xtroll. The company manufactures a range of products under the categories of: Rust treatment and prevention, Paint and coatings, Concrete Masonry and Asbestos sealers and coatings, Timber sealers and coatings, and Cleaning products. The world class products give customers great value for money, due to a combination of high coverage rates, product excellence and the simple fact that they really work. Additionally the company provides customers with complete technical advice about the products and their many and varied applications.

As always the primary focus of the company will be to provide quality products that put simply, really do work. The extensive range of Xtroll products fits this bill, and of course this includes Xtroll’s amazing corrosion treatment and prevention products. Led by Xtroll’s flagship product Rust Conqueror and very well supported by products like Xtroll Silver, Xtroll Metalguard and Xtroll GP Primer, these products when used correctly can, will and do treat and stop existing corrosion on any metal. Additionally the products can be used to prevent the onset of rust on all new metals. Xtroll products are easy to use, normally only requiring basic preparation and being simple to apply correctly.

Air and moisture

Layer of rust particles

Metal substrate In the diagram above air and moisture are able to penetrate through the rust layer and make contact with the metal surface which promotes yet more rust.

Air and moisture

Metal substrate In the diagram above the Rust Conqueror has penetrated the rust layer and encapsulated it into the protective film. This process prevents air and moisture from being able to contact the metal surface, therefore treating both the existing rust and also preventing further rusting.

Layer of rust particles that have been treated with Xtroll Rust Conqueror

Rust Conqueror effectively uses the rust on the metal when being used to treat rust. To prepare the surface for treatment simply remove loose flaky material, degrease and rinse. Once dry apply Rust Conqueror in multiple light coats until a glossy varnish like finish is achieved. This system ensures that the product penetrates, saturates and encapsulates all of the rust, effectively binding the rust back to the material, while at the same time locking all air and moisture out. The completed system can be painted over with either solvent based or water based products so long as appropriate drying times have elapsed. Rust Conqueror is based on organic products and is safe and easy to apply. Rust Conqueror can be applied in a wide variety of environments and temperatures making it exceptionally versatile.

When used as part of a system with Xtroll Silver or Xtroll Metalguard, the life of aged materials can be significantly improved. This fact coupled with the ease of preparation and application, mean that you can really save money on maintenance costs. Simpler easy to achieve preparation saves you time, while ease of application means no special equipment or training is required. Add these facts to the excellent coverage rate offered by the products and the simple truth is that you will save time and money which is crucial in today’s economic climate.

Rust Conqueror is also an ideal rust preventative when used to protect new metals.

Simply degrease and rinse the surface to which it is to be applied and once dry apply sufficient product to ensure a gloss varnish like finish. This ensures a non porous finish which effectively prevents air and moisture from contacting the surface therefore preventing rust. Being essentially a clear coating that will last more than 18 months in direct sunlight, with a coverage on new material of up to 30 square meters per litre, and being readily coated with either enamel or acrylic paints after a simple wash and rinse to remove any contaminants that may have settled on the surface, the product is ideal and economical for use as a protective coating on materials that may be prone to rusting while in storage or transport.

For more information on Xtroll products or to find your nearest supplier please contact Global Paint Solutions via, email sales@xtrollglobal.com. au, Ph 02 6568 4040, Fax 02 6568 2971 or via Mobile 0488 438 438.

Alternatively visit xtrollglobal.com.au to view the full Xtroll range of products on line.

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ISSN 1326-1932 Published by The Australasian Corrosion Association Inc. ABN: 66 214 557 257 Publications Director Mohammad Ali – GHD, MAli@ghd.com.au Editor Brian Cherry – Monash University, Brian.Cherry@monash.edu Associate Editors Research: Bruce Hinton – Monash University, bruce.hinton@monash.edu Professional Practice: Willie Mandeno – Opus International Consultants, willie.mandeno@opus.co.nz News: Ian Booth – Australasian Corrosion Association, ibooth@corrosion.com.au Reviewers Andy Atrens – University of Queensland Nick Birbilis – Monash University Lex Edmond – Monash University Harvey Flitt – Queensland University of Technology Maria Forsyth – Monash University Rob Francis – Aurecon Australia Warren Green – Vinsi Partners Doug John – Curtin University of Technology Graeme Kelly – Corrotec Services Nick Laycock – STOS Grant McAdam – Defence Science and Technology Organisation David Nicholas – Nicholas Corrosion John Robinson – Mount Townsend Solutions Paul Schweinsburg – Queensland University of Technology Raman Singh – Monash University Graham Sussex – Sussex Material Solutions Tony Trueman – Defence Science and Technology Organisation Geoffrey Will – Queensland University of Technology David Young – University of New South Wales Advertising Sales Wesley Fawaz - wesley.fawaz@corrosion.com.au Ph: 61 3 9890 4833, Fax: 61 3 9890 7866 Subscription Print Version: ISSN 1326-1932 Subscription rates to non members: Within Australia: A$72.60, incl GST, single copies A$16.50, incl GST Outside Australia: A$77, excl GST posted airmail, single copies A$22 incl GST On-Line Version: ISSN 1446-6848 Subscription rates to non members: A$22 incl GST The views expressed in Corrosion & Materials are those of the individual authors and are not necessarily those of the ACA. Publication of advertisements does not imply endorsement by the ACA. Copyright of all published materials is retained by the ACA but it may be quoted with due reference.

Australasian Corrosion Association Inc PO Box 112, Kerrimuir Vic 3129, Australia Ph: 61 3 9890 4833, Fax: 61 3 9890 7866 Email: aca@corrosion.com.au Internet: www.corrosion.com.au President: Ian MacLeod Chief Executive Officer: Ian Booth Operations Chairman: John Grapiglia Finance Director: Paul Vince Senior Vice President: Peter Dove Junior Vice President: Allan Sterling Immediate Past President: Roman Dankiw Technical Director: Graham Sussex Education Director: Geoffrey Will Membership Director: Fred Salome Communications Director: Bryan Pike Publications Director: Mohammad Ali Newcastle Representative: Matthew Dafter New Zealand Representative: John Duncan Branches & Divisions Auckland Division: Sean Ryder 64 9 261 1400 Newcastle: Karen Swain 61 0 418 854 902 New South Wales: Denis Jean-Baptiste 61 0 404 646 272 Queensland: Cathy Sterling 61 7 3821 0202 South Australia: Alex Shepherd 61 8 8267 4744 Tasmania: Grant Weatherburn 61 0 418 120 550 Taranaki Division: Ron Berry 64 27 671 2278 Wellington Division: Alistair MacKenzie 64 4 473 3124 Western Australia: Gary Bennett 61 0 408 413 811 Victoria: John Tanti 61 3 9885 5305 Technical Groups Cathodic Protection: Bruce Ackland 61 3 9890 3096 Coatings: Matthew O'Keeffe 61 437 935 969 Concrete Structures & Buildings: Frédéric Blin 61 3 9653 8406 Mining Industry: Peter Farinha 61 8 9456 0344 Petroleum & Chemical Processing Industry: Fikry Barouky 61 402 684 165 Research: Nick Birbilis 61 3 9905 4919 Research: David Young 61 2 9385 4322 Water & Water Teatment: David Mavros 61 419 816 783 Welding, Joining & Corrosion: Graham Sussex 61 3 9495 6566 Young Corrosion Professionals: Erwin Gamboa 61 8 8303 5473 www.corrosion.com.au *all the above information is accurate at the time of this issue going to press.

4 » President’s Message 5 » 2012 ACA Events Calendar 6 » Chief Executive Officer’s Message 8 » News 17 » ACA Branch News 18 » ACA Standards Update 21 » University Profile: Deakin University 24 » ACA Certified Corrosion Technologists and Technicians 26 » C&P 2012 Call for Papers 28 » ACA Corporate Members 30 » P roject Profile: Cathodic Protection of a 1.2km long Harbour Tunnel 33 » Coatings Group Member Profile 34 » T echnical Note: Copper Based Antifouling Coatings on Aluminium Hulls 36 » T echnical Note: Effect of Surface Roughness on the Corrosion of 316-type Stainless Steel 38 » Research Paper: Shedding light on Corrosion 44 » R esearch Paper: Underprotection of Mild Steel in Seawater, the Calcareous Film 49 » Suppliers and Consultants

Front Cover Photo Shell Todd Oil Services Maui Production Station Oaonui, New Zealand. The Maui Coating Refurbishment Project 2011. Pipe rack painting – Carboline Coatings.

The ACA is a founder member of the World Corrosion Organization

Vol 36 No 6 December 2011

3

Lookout!!!

Another successful ACA conference is over, or should I say an International Corrosion Congress this time. Our congratulations and thanks goes to the team in WA and all the volunteers who assisted putting together a phenomenal technical programme and a conference to be remembered.

It goes without saying the smooth running and professionalism of our conferences does not happen without those behind the scenes, namely Ian Booth and his team at the ACA Centre as well as numerous volunteers supporting the local Branch. So thankyou!

That’s enough of living in the past as it’s now time to look forward and go back to where it all began some 57 years ago to where the ACA held its very first conference. Melbourne!

That’s where, in 2012 the best ACA conference ever will be held. So get out your iPhone, Android or computer and lock in November 11th to 14th 2012 in your Lotus Notes or Outlook. The Victorian Branch is looking forward to welcoming everyone to Melbourne!

What other associations have members with such a wide diversity of backgrounds from blasters and painters, cathodic protection technicians and designers at the front line of corrosion mitigation, manufacturers and suppliers of corrosion mitigation products and equipment, to internationally recognised academics and researchers who provide the insight into corrosion mechanisms and its mitigation, all meeting as peers with a common interest?

Our conferences and Branch meetings foster this community to broaden our understanding of corrosion issues, so get out of your comfort zone and attend some Branch meetings as you’re never too old to learn something new!

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Corrosion & Materials

Membership is the life blood of our association and with a target of achieving 2,000 members in our strategic plan by 2014 we can all help promote the benefits of membership of The Australasian Corrosion Association Inc to our friends, associates and other business acquaintances. Not only will our association be stronger, but as individuals we can increase our network of corrosionists and possibly find a shortcut to a corrosion mitigation solution.

So what is the ACA about? Our constitution states our purpose as “…a non-political, non-profit organisation established for promoting the co-operation of academic, industrial, commercial and governmental organisations in relation to the mitigation and dissemination of information on all aspects of corrosion and its prevention by promoting lectures, symposia, publications, training and other activities.”

Some of the objectives from the same constitution are: To improve and disseminate knowledge of the arts and sciences of the prevention and mitigation of corrosion and allied arts. To develop a co-operative spirit of friendship and mutual assistance among members.

To consult with educational authorities, teachers and others to improve the standard of education in those branches of science in which the Association is interested.

To initiate and sustain research, hold meetings for the presentation and discussion of technical papers; develop publish and distribute technical treatises and pursue other related activities.

Keeping these in mind, the year ahead provides some challenges as we continue to grow. The recent minor changes to the constitution will allow us to review, update and modernise it to reflect for our future

requirements and to better serve the needs of all our members.

And now is the time we should all start to lookout! Looking outside the membership to spread the word about the corrosion problems society faces and to inform and educate our communities how corrosion mitigation benefits society both economically and environmentally.

Some of the ongoing ACA initiatives to achieve this are (but not limited to): Upgrading the ACA website for easier navigation with ongoing improvements.

Uploading past conference papers in the member’s login section with the abstracts available to the general public, allowing better research of corrosion topic and acknowledging the contribution by the authors of the papers.

Updating the school corrosion education website to reflect the new national curriculum for use by science teachers in Years 11 and 12.

A World Corrosion Awareness day to be scheduled.

The Young Corrosion Group (YCG) was re-launched in 2011 with the focus on engaging those new to the industry, particularly the under 35 demographic. A steering committee has been formed to support these efforts, so lookout for YCG targeted events including technical nights and networking events in each Branch's calendar next year.

I ask that you all support the ACA regular activities in 2012 through the ACA Centre, your local Branch and technical groups and to spread the word to one and all of the need to understand and mitigate corrosion at all levels of our community.

As Neil Young's 1978 concert tour album reminds us, “Rust Never Sleeps!”

Peter Dove

2012 ACA Events Calendar The ACA Centre along with the ACA Technical Group committees can confirm the listed events below for 2012. ACA members will receive further details on each event as appropriate throughout 2012, but for now, please include these in your 2012 diary.

Event Title

Event Type

2012 Date

Location

Future Leaders Forum

Young Corrosion Group Forum

22 - 23 February

Sydney

Corrosion and Risk Management

Road Show Seminar

1 May

Darwin

Corrosion and Risk Management

Road Show Seminar

3 May

Gladstone

Corrosion and Risk Management

Road Show Seminar

8 May

Newcastle

Corrosion and Risk Management

Road Show Seminar

10 May

Wollongong

Corrosion and Risk Management

Road Show Seminar

15 May

Tasmania

Corrosion and Risk Management

Road Show Seminar

17 May

Melbourne

Corrosion and Risk Management

Road Show Seminar

22 May

Adelaide

Corrosion and Risk Management

Road Show Seminar

24 May

Perth

Corrosion and Risk Management in the Marine Environment

Seminar

29 May

Auckland

Corrosion and Risk Management in the Marine Environment

Seminar

31 May

Wellington

Rust: Exploding the Myths! Exploring the Truth.

Petroleum & Chemical Process Industries Technical Group / Oil & Gas Industry Mid-Year 30 - 31 May Meeting

Brisbane

Corrosion Prevention and Coating Durability

Coatings Technical Group Mid-Year Event

6 - 7 June

Sydney

Concrete Repair and Protection: Some Concrete Structures & Buildings Technical Contemporary Issues Group Mid-Year Event

21 June

Newcastle

Corrosion Issues, Prevention and Asset Rehabilitation in the Water and Waste Water Industry

Water & Water Treatment Technical Group Mid-Year Event

26 June

Adelaide

ACA Research Matters

Research Technical Group 1/2 Day Meeting

5 July

Sydney

Meeting of the Australian Electrolysis Committee

Cathodic Protection / Australian Electrolysis Committee Meeting

19 July

Adelaide

Corrosion and Infrastructure Sustainability in the Mining Industry

Mining Industry Technical Group Mid-Year Event

27 July

Mackay

Corrosion and Infrastructure Sustainability in the Mining Industry

Mining Industry Technical Group Mid-Year Event

17 August

Singleton / Muswellbrook

Welding & Corrosion Mitigation in the Petroleum & Chemical Processing Industry

Petroleum & Chemical Process Industries / Welding, Joining & Corrosion Technical Groups Mid-Year Event

28 August

Perth

Corrosion & Prevention 2012

ACA Conference

11 - 14 November

Melbourne

Branch Events Each of the eight ACA Branches will conduct regular technical events throughout 2012. To enquire, you may contact your local Branch at the following email addresses: New South Wales: nsw@corrosion.com.au New Zealand: nz@corrosion.com.au Newcastle: ncl@corrosion.com.au Queensland: qld@corrosion.com.au

South Australia: sa@corrosion.com.au Tasmania: tas@corrosion.com.au Victoria: vic@corrosion.com.au Western Australia: wa@corrosion.com.au

Please refer to www.corrosion.com.au for up to date details on all ACA activities. www.corrosion.com.au

Vol 36 No 6 December 2011

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Recognising tremendous personal contributions The past four years of ACA’s history have been in some ways the most turbulent and yet in others they have seen a considerable amount of change, consolidation and growth.

ACA members are fortunate that their interests are represented at different levels of the association’s governance structure by a committed group of volunteers who devote considerable time and expertise in guiding staff on how ACA should develop and in particular how member benefits can be delivered. Some would suggest that the contribution also involves blood, sweat and the occasional tear and may even extend to the odd pound of flesh.

An important instrument of policy development and managerial control is ACA’s Operations Committee (Board). The Board is led by its Chairman who can occupy that position for a maximum of two terms, typically a total of four years.

During the period 2007 to 2011 John Grapiglia has been Chairman of ACA’s Board.

John has presided over major changes in staff – six additional new staff members have been appointed since November 2008, the consolidation of ACA’s finances, the accumulation of healthy reserves, the purchase of additional office premises, the development of a range of new policies, a dramatic improvement in the management of ACA’s conference activities, an increase in the number of technical events and the expansion of education and training opportunities for members and the wider industry.

Certainly things have not always been plain sailing but John has managed to focus the Board’s attention on a strategic approach which has delivered great benefits.

The 2011 combined ACA ICC conference, the biggest that ACA has ever conducted was the result of a bid managed and presented by John back in October 2008.

in its content and impact during John’s tenure.

John will be succeeded by another highly capable and committed volunteer. Just who that will be is something that will be announced following on from the Council meeting conducted towards the end of November. John’s successor will have a solid base upon which he can continue to guide the building of ACA’s future.

Other key appointments to ACA’s Board will result from this year’s Council meeting. All changes will be announced in the near future. ACA’s 2010 - 2011 President, Ian MacLeod will pass the baton onto Peter Dove.

I am certain Peter’s contribution and leadership of a unified Australasian association will be as exciting as that achieved by Ian during his term.

ACA’s flagship publication, Corrosion & Materials has grown significantly

From all the team at ACA, we wish you and your staff a Merry Christmas and a prosperous New Year!

The ACA Centre will be closed on Friday 23rd December 2011 and will re-open on Monday 9th January 2012

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Corrosion & Materials

Corrosion Technology Certificate Member Status Fee GST AU Member $1922.73 $192.27 AU Non Member $2254.55 $225.45 NZ Member* $1925.00 NZ Non Member Adelaide March 26th – 30th Perth July 16th – 20th Sydney December 03rd – 07th Introduction to Protective Coatings Member Status Fee GST AU Member $500.00 $50.00 AU Non Member $618.18 $61.82 NZ Member* $455.00 NZ Non Member Adelaide May 01st New Zealand November 30th Protective Coatings Quality Control Member Status Fee GST AU Member $1286.36 $128.64 AU Non Member $1568.18 $156.82 NZ Member* $1285.00 NZ Non Member Adelaide February 20th – 22nd Newcastle June 13th – 15th New Zealand July 25th – 27th Melbourne November 26th – 28th Coatings Selection and Specifications Member Status Fee GST AU Member $1286.36 $128.64 AU Non Member $1568.18 $156.82 NZ Member* $1285.00 NZ Non Member Sydney March 05th – 07th Perth July 18th – 20th Melbourne November 08th – 10th Coatings Inspection Refresher Member Status Fee GST AU Member $500.00 $50.00 AU Non Member $618.18 $61.82 NZ Member* $455.00 NZ Non Member Sydney January 30th Brisbane June 15th Perth December 04th Introduction to Cathodic Protection Member Status Fee GST AU Member $500.00 $50.00 AU Non Member $618.18 $61.82 NZ Member* $455.00 NZ Non Member Brisbane February 06th Cathodic Protection Monitoring Member Status Fee GST AU Member $1286.36 $128.64 AU Non Member $1568.18 $156.82 NZ Member* $1285.00 NZ Non Member Tasmania March 19th – 21st Sydney May 21st – 23rd Adelaide October 22nd – 24th Cathodic Protection Advanced Member Status Fee GST AU Member $1922.73 $192.27 AU Non Member $2254.55 $225.45 NZ Member* $1925.00 NZ Non Member Sydney May 28th – 01st Perth August 06th – 10th

www.corrosion.com.au

Total Fee $2115.00 $2480.00 $2255.00

Total Fee $550.00 $680.00 $620.00

Total Fee $1415.00 $1725.00 $1570.00

Total Fee $1415.00 $1725.00 $1570.00

Total Fee $550.00 $680.00 $620.00

Total Fee $550.00 $680.00 $620.00

Total Fee $1415.00 $1725.00 $1570.00

Total Fee $2115.00 $2480.00 $2255.00

Corrosion & CP of Concrete Structures Member Status Fee GST AU Member $918.18 $91.82 AU Non Member $1150.00 $115.00 NZ Member* $920.00 NZ Non Member Sydney March 14th – 15th

Total Fee $1010.00 $1265.00 $1150.00

ACA/ACRA Corrosion & Protection of Concrete Structures Member Status Fee GST Total Fee AU Member $918.18 $91.82 $1010.00 AU Non Member $1150.00 $115.00 $1265.00 NZ Member* $920.00 NZ Non Member $1150.00 Wollongong March 14th – 15th Tasmania October 04th – 05th NACE - Coatings Inspection Program CIP Level 1 Member Status Fee GST Total Fee AU Member $3236.36 $323.64 $3560.00 AU Non Member $3700.00 $370.00 $4070.00 NZ Member* $3235.00 NZ Non Member $3715.00 Brisbane Jan/Feb 30th – 04th Sydney March 19th – 24th Darwin April 16th – 21st Adelaide May 07th – 12th Newcastle June 18th – 23rd Perth August 13th – 18th Tasmania September 03rd – 08th New Zealand October 08th – 13th Melbourne Oct/Nov 29th – 03rd Perth December 03rd – 08th NACE - Coatings Inspection Program CIP Level 2 Member Status Fee GST Total Fee AU Member $3236.36 $323.64 $3560.00 AU Non Member $3700.00 $370.00 $4070.00 NZ Member* $3235.00 NZ Non Member $3715.00 Brisbane February 06th – 11th Sydney March 26th – 31st Adelaide May 14th – 19th Melbourne July 02nd – 07th Perth August 20th – 25th New Zealand October 15th – 20th Melbourne November 05th – 10th Perth December 10th – 15th NACE – Peer Review CIP Level 3 Member Status Fee GST AU Member $1271.82 $127.18 AU Non Member $1493.64 $149.36 NZ Member* $1272.00 NZ Non Member Melbourne November 11th – 13th

Total Fee $1399.00 $1643.00 $1494.00

Resits NACE – Coating Inspector Program Level 1 & 2 Member Status Fee GST Total Fee AU Member $863.64 $86.36 $950.00 AU Non Member $1090.91 $109.09 $1200.00 NZ Member* $865.00 NZ Non Member $1110.00 Examination Tests will be conducted to coincide with scheduled programs – contact ACA for details To check the currency of this information please view the latest information at www.corrosion.com.au * All NZ courses are GST free

Vol 36 No 6 December 2011

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ACA website update The ACA has recently updated its website. There is a new member’s area where members can access their membership information as well as ACA member only benefits. To logon, ACA members will need to register to receive a special username and password which will be emailed to you. To register, you will need your five digit member number. To register for the member login section on the website, go to www.corrosion.com. au and click on the Members Login button on the homepage.

The functionality of the member area will increase in the future as new modules are added. We aim to have online payment of ACA membership fees and online registration for events operational in 2012.

Searching conference proceedings The ACA are very excited to announce that all ACA members can now search the last 15 years (19962010) of ACA conference papers online. Full pdf documents can be selected and printed as required.

Please note that a pdf viewer such as Adobe Reader or similar is required to view pdf documents.

To search the conference papers, ACA members can enter the title,

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The % gloss retention data of a coating tabulated after exposure to atmospheric resilience to thermal and/or photooxidativ UV light is an indication of the coatings e degradation reactions (as described traditionally chosen for testing purposes above). White pigmented coatings as white pigmentation (rutile TiO ) are superoxide and hydroxide ions to hydroxyl 2 upon absorption of UVBack light converts oxygen to radicals. The photoactivity of TiO is thus used by coatings chemists to accelerate the UV induced degradation further of the polymers under test. QUV data 2 has been used by many coatings chemists simulate what would happen to a coating in the ‘real world’. Many papers have to studies offer a comparative guide to been published on this subject, whilst exterior QUV performance The need to reduce they cannot VOC has meant replicate that‘real QUV B is NOT a good indicator of most data’. formulations As we will have see focused from on: this study real world performance (refer to the gloss retention data extracted from 5 Allunga and QUV B studies for the waterborne coatings degrees North , New Generation1.420 g/l Siloxane. <refer Figures 1 and 2>).

2.

Print solvent free coatings (eg polysiloxane variants)

3. powder coatings Allunga Weathering 4.

120

o

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(5 degrees North)

80

Retention 60

RECENT ADVANCES IN POLYSILOXANE COATINGS

*Ameron (New Zealand) Limited

40 20 0 0

Months

UV light

New Generation PSX 420 g/L (5°

Polymer

Propagation step P• +

O2

N)

PU

P•

POO• Discoloration POO• + Allunga Weathering PH

3

Hemmings** and L. Bailey** **Ameron

3 (Australia) Pty WHY ARE SILOXANE COATINGS UNIQUE? The energy content of one mole (one quanta) of UV light is sufficient to destroy the covalent bonding network most polymeric materials. Free radicals prevalent in are generated by Summary:. the photophysical Thisprocesses publication of adsorbed 10generation of briefly UVdescribes light. The nett 20 hydroperoxide the result 30 s and peroxides performanc is i.e. the 50 40 polymer e and mechanical property attributes up being of ends a newly photo oxidized 60 patented (refer scheme polysiloxane one). (3) The technology technology.

Initiation step

Epoxy Siloxane

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UV and/or hot melt technologies Each of these chemistries has its own problems but in general liquid, ambient cure technologies generally use low weight, highly functionalised diluents molecular which generally create durability problems for the formulator/ end user.

Polysiloxane coatings offer a unique ‘fix’ to this problem as highly skilled organic chemists have been able to viscosity organic polymers with solvent hybridize low free properties and attributes of a new generation silicon functional diluents and oligomers. This paper will focus on some of siloxane coatings which have rapid VOC and extreme durability. This cure, excellent corrosion resistance, low dissertation will compare LHP and contrast Gommans the properties conventional coatings and other siloxane * of Chu* this class K of Constable coatings with * E. coatings which are present in the marketplace. S Yi

100 gloss, %

Next

Termination step

P•

+

P•

2 PO•

manifests itself as a low VOC, rapid curing technology, curing quickly at VOC’s as low as 120 g/l. Two technologies are described in this paper, one at of differing VOC’s 120 g/l and the other at 420 g/l. These technologies have been compared and contrasted with conventional, NISO non compliant polyurethane and NISO (i) technologies.

Keywords:

Polysiloxane , VOC, Durability, Rapid Cure, Isocyanate (ii) Free POOH + P• (iii) 1 INTRODUCTION P-P

Polysiloxane coatings (1) are unique class of coating as they offer the coatings formulator some outstanding attributes, the key features of this (iv)technology are: some of

POOP 1.

Extremely (v) low VOC (as low as 100 g/L depending upon the formulation route taken).

2.

POP Outstanding (breakthrough) colour and gloss retention (vi) (again dependant upon the unique organic resin componentry utilised). blend of inorganic3.

Extremely good abrasion, dirt pickup and graffiti resistance properties (again formulation dependant).

Scheme One: Photooxidatio4.n induced Betterby UV light corrosion resistance at lower dft’s when used The combined effects of photolysis in combination with inorganic zinc, tolerant epoxies. and photooxidation of polymers leads epoxy zinc and surface to chain scission and/or crosslinking UV degraded polymer. The nett effect 0 reaction of the of these processesMost is obvious polysiloxane to all coatings technology reduction in tensile and mechanical chemists is based i.e. chalking, on 2K chemistry cracking, but checking, property strength andoriginally 0 1K siloxane coatings can be formulated 10 fails. change indeveloped 20 glass transition its siloxane 30 as well. Ameron temperature. technology 40 In simple (Epoxywords 50 Siloxane) the coating for structural steel and concrete to 60 Coat Coating system (2 epoxy coats/1 P/U coat). replace the conventional 3 The advantages of siloxane chemistry Months Silicon based polymers has pioneered in this area there exists are well are uniquely resistant to photolysis documented, and as Ameron a wealth of literature for the interested oxidation. This can easily considers that: reader to delve into (1). This paper someand newphoto generation rationalized when one polysiloxane coatingsbe discusses which have been developed with the OEM OEM and new project markets, of course New Generation PSX 420 g/L (5° and new projects markets in mind. , have differing requirements to the 1.

The Si-O bond is alreadyN) NISO Maintenance/PC/Marine area- namely oxidizedPU in an speeds improved oxidizedand flexibility. state and unlike This new rapid cure Carbon-Carbo siloxane chemistry further. n bonds has been compared with conventional cannot be oxidized (Acrylic/Acrylic or Acylic/Epoxy) urethane and NISO technologies. Mechanical property attainment, durability (real world Figure one: ‘Real data’ – Gloss/ colour 2.

The bond strength or bond dissociation corrosion resistance and an environmental perspective relating and laboratory), retention data energy to the VOC’s for a C-C that from bond siloxane can Allunga be is 145 attained chemistries Kcal/mole through formulation of IPN Kcal/mole (measured atexposure 298K) (4)site northern queensland.will be presented. cf. a Si-O bond which is 193.5 Figure two details the % gloss retention Polyurethane coatings have been offered In addition chemistry of the siloxane up as the doyen of coatings on a global same coatings is also extremely as experimental resistantbecause to thermal ly determined basis for many, many generations. oxidation polyurethanes in QUV look at the chemistry of everyday studies.reactions offer an to use an analogy excellent This is onerange all around needsofonly glass (a giant siloxane to properties polymerinnetwork). to the applicator, architect and specifier However, recent years Glass o cooling yields an extremely chemically for example polyurethane meltshave coatings alike. at 1400 comeCunder and upon resistant and thermally a health and safety cloud as this technology workerresistant safety (respiratory material. To common inorganic zinc or heat resistant use a coatings sensitisation) has issues with analogy one(dropping and compliance could utilize siloxane coatingstechnology). below 250 g/l in VOC is an extremely which are capable Polysiloxanes, of providing greater. difficult task for this as welong o willterm see heat fromresistance this paperatmay 760 offer C or a solution as a safer, more durable, lower VOC technology. faster drying and 4 GLOSS RETENTION OF SILOXANE COATINGS 2 CF. THE WORLD, COATINGS ORGANIC GREENHOUSE GASES, VOC EMMISSION S AND THE FUTURE Figure one details the gloss retention (60 degree) and colour The retention need to conserve of a goodenergy no more apparent qualityis polyurethane used NISO coatings, an epoxy siloxane thantwo coating, when one looks to the language used in commonly (VOC 120 g/L) protocol andgeneration and a new also continued pressure the preamble to the Kyoto data’ as transcribed from the Allunga on fuelcoating. cure siloxane and gasThis & Prevention prices.

2004 Paper 054rapid dataTois state Page 3 exposure Corrosion ‘realthe obvious, burning fossil fuels for energy creates greenhouse station in Northern gases, Queensland. including of course CO2. (2) Unfortunately, generation greenhouse gases have a lifespan in many hundreds of years, thus generation the stratosphere of of greenhouse gases is a problem which Corrosion & Prevention 2004 Paper will have ramifications for many generations.

From a coatings perspective then the 054 Page 2 message is simple- develop coatings with long lifetimes to first maintenance, low levels of solvent (to reduce generation that contain of tropospheric low level ozone/smog) cure them. and that do not need external heat sources to P•

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author or keywords of the papers they are looking for and click on the title link to see the entire paper. The system is designed to make finding what you’re looking for as easy as possible and if the search you are using doesn’t generate any results, it will check for similar words and build a list of suggestions. If you are searching for something extremely

specific you can search for an exact phrase by enclosing the words between double quotes.

Non members will be able to search the abstracts of the ACA conference papers in the near future; however the full contents of all papers will be available to members only.

Corrosion & Prevention 2004 Paper

054 Page 1

If you have any queries, please contact the ACA on +61 (0)3 9890 4833 or via the “Contact Us” form on the website, or via email at aca@corrosion.com.au We would welcome all feedback about the new website.

Carboline has been global leader in the High Performance Coatings industry for over 63 yrs. For corrosion solutions and coating systems that are cost effective, talk to the Protective Coatings Professionals.

NEWS

ACA appoints Branch & Membership Support Officer The ACA has appointed a Branch & Membership Support Officer to work with key ACA staff, Branch Officers and other stakeholders to improve the delivery of existing ACA Branch support and membership services, to assist in the development and delivery of an enhanced range of Branch and membership services and organisational responses across the range of ACA activities.

Solonge Brave started the role at the ACA on the 1st December 2011.

Solonge has relevant association experience after working in a similar role over the past two years at the Concrete Institute of Australia. She is familiar with association national and branch structures and is experienced in many of the duties proposed for the new role.

The newly created role eventuated from strategic planning conducted during the year by ACA staff and

the Operations Committee and is required to achieve objectives set out in the ACA’s 2012-2014 strategic plan.

The role will include (but not limited to) duties such as: Branch Support Develop a Branch Operations Manual

Assist with Branch level surveys to members Membership Process new member applications and associated correspondence Receive and respond to routine membership enquiries

Assist to develop Branch event reports for Operations Committee

Conduct membership recruitment and retention programs

Distribute information between Branches

Act as first point of contact for basic complaints from members

Distribute information between Australasian office and Branches

Administer a member recognition program

Distribution of Branch Newsletters

Prepare regular membership analysis reports

Support to Branches for events Support for Branches for event registrations

When you receive an email or phone call from Solonge, please make her feel welcome.

YCP turns into YCG The ACA’s Young Corrosion Professionals group formed in 2007 recently re-established itself as the ‘Young Corrosion Group’ steering committee.

ACA staff facilitated an extensive planning day held in Adelaide in August this year with all members of the new steering committee.

A new framework was established along with an operational plan to implement the objectives set out in the framework.

Mission The Young Corrosion Group serves the purpose of organising and implementing events of value to young and those new to the corrosion industry and to provide a platform of access to information and networks which are of benefit to personal, professional or business development.

10 Corrosion & Materials

Target Market Under 35, new to the corrosion industry and/or interested in the corrosion industry.

2012 Activities The YCG steering committee aim to achieve in 2012: A Future Leaders Forum – a two day professional development workshop (see page 9 for further details) A full day site visit excursion in each of their local cities A corrosion trivia night in each of their local cities Two basic corrosion 101 technical nights in each of their local cities

Members of the YCG steering committee include: Dean Ferguson of GHD in Victoria Erwin Gamboa of the University of Adelaide in South Australia Giles Harrison of Extrin Consultants in Western Australia Sean Ryder of GHD in New Zealand James Wu of Jemena in New South Wales The ACA hopes to include a YCG steering committee member from each Branch in the future.

For further information regarding the YCG, its events or to be added to its database, please refer to the YCG webpage at www.corrosion.com.au, email ycg@corrosion.com.au or find us on Facebook.

Future Leaders Forum Applications are open for future leaders of the corrosion industry to attend an ACA Future Leaders Forum in Sydney on the 23-24 February 2012.

The forum is an ACA funded initiative (all flights, accommodation, etc to be covered by the ACA) and is limited to 20 delegates.

The two day personal and professional development forum aims to draw together young professionals across the spectrum of the corrosion industry focusing on developing

competencies in how to present technical papers, chair technical sessions, conduct group discussions and develop the art of expressiveness and communication in a professional and friendly environment.

Application Details Applications close Thursday 15th December 2011 Applicants must be either members of The Australasian Corrosion Association Inc or be currently employed by one of the associations corporate members

Applications must be supported by employers by providing a letter from immediate managers Applicants must be currently working full time in the industry Applications forms, terms and conditions and further information is available on the ACA YCG webpage at www.corrosion.com.au

Newcastle Branch to again fund young corrosion professionals to ACA annual conference If you are a ‘young corrosion professional’ either working or studying in a corrosion related field within Australia or New Zealand and have always wanted to attend the annual ACA conference but never had the opportunity, this maybe your chance.

Starting in 2011, the ACA Newcastle Branch has been sponsoring a Young Corrosion Professional Award, with the aim to foster involvement in the ACA by emerging industry professionals. This award subsidises attendance at the annual ACA conference to a value of up to AU$3,500.

The award is open to undergraduate students, post-graduate students and those working in the corrosion industry from across the ACA membership that meet the criteria of young professional status (under the age of 35) in the ACA. Applicants are required submit an application outlining their technical background and including a short abstract of their research or area of interest. This may be based on (but is not limited to) a research or field project, item of particular local or historical relevance or industrial case study. Selected applicants will be invited to present

their work to the judging panel (15 — 20 minutes) from the ACA Newcastle Branch committee.

Applications will be open during February - April 2012. The Newcastle Branch will advise those applicants invited to speak to the Newcastle judging panel during May — August 2012.

Further details regarding presentation criteria, award details and application procedures can be viewed on the ACA website or obtained by emailing aca@corrosion.com.au

NEWS

ACA welcomes new members Corporate Members 3C Corrosion Control Company www.3ccc.net Based in Sweden, 3C Corrosion Control Company is a cathodic protection company devoted to work with corrosion control in cooling water systems. The company has products such as a series of rectifier modules ranging from 1 A to 500 A, a range of special anodes made of MMO coated Titanium and the worldwide responsibility to market a new patented corrosion probe, the LC probe.

TAFE NSW - Sydney Institute www.sit.nsw.edu.au TAFE NSW – Sydney Institute is Australia’s largest VET provider in Australia. They enrol more than 70,000 students in 800 courses and training programs offering flexible study options, workplace training, online and distance learning across seven colleges. They work closely with employers, industry skills councils, schools and universities to ensure courses offer seamless pathways for students seeking employment or tertiary study, and others seeking retraining opportunities.

Jason Mulligan

Australian Maritime Systems www.maritime-system.com The primary objective of Australian Maritime Systems (AMS) is to assist the providers of maritime services with engineering support to provide high quality innovative and cost effective systems of maritime service delivery. AMS has worldwide experience in the specialised areas of maritime technology enabling it to efficiently and effectively manage, construct and maintain aids to navigation networks, maritime information systems and associated maritime assets varying in complexity and size.

Vengatesh Naidu of Impsa (Malaysia) Sdn Bhd Dhinesh Narayan of Auckland Abrasive Blasting & Coatings (2005) Ltd Daniel Neagoie of Shell Refining (Australia) Pty Ltd Craig Oliver of ELLIS Plantequipment Painters Jeff Pritchard of Duoguard Australia Pty Ltd Julia Ratnayake of RTA, SHB Alliance Kim Riseborough of Riseborough Inspection Services

Individual Members Justin Batterbee of AGC

Anthony Scott of Worley Parsons

Neal Benn of Argyle Spraypainting

Damian Smith of Delmark Consulting

Tom Button of Robayne Distributors Scott de Groot of QA Inspection Services Pty Ltd

Lex Stolk of Floor-It Services

Rodney DeWorsop

Andrew Tomlinson

Darren Hawkes

Semi Uele of Auckland Abrasive Blasting & Coatings (2005) Ltd

David Tawfik of Tawfik Group

Theodor Paul Lylo of Kaefer Intergrated Services

Joji Uppan of AMMS Group

Terry Mason

Urs Zaugg

New appointments at Jotun Australia Recently relocating from Jotun's Headquarters in Norway to join Jotun Australia's Protective Coatings team in Melbourne is Anette Walle as ISM & Mining Concept Manager Australia.

Educated in International Business & Marketing, from BI Norwegian School of Management and China's Fudan University, Anette joined Jotun in 2007 as one the company's first global trainees.

In her time with Jotun, Anette has worked with global key accounts and worldwide projects, handling both

12 Corrosion & Materials

accounts as well as supporting on the strategic development of Jotun's key account team. In Australia, Anette will continue to focus on global key accounts and their projects, but also taking the responsibility to develop Jotun's activities in the Mining area.

Anette’s appointment complements some other recent additions to the Jotun Australia team as a result of sustained strong growth. Christophe Piquard (Protective Sales Manager WA & NT) and Dave Simpson (Marine Sales Manager WA & NT)

have joined Jotun in Perth bringing significant experience from previous employment in the region. Dean Wall has joined Jotun in Tasmania and will also provide support to the activities in New Zealand and is well known to the coatings industry in Australia with extensive involvement over many years.

All of these appointments reflect the role played by Jotun in the vigorous coatings industry in Australia.

Sorel Award Winners 2011 The Galvanizers Association of Australia Sorel Award winner for 2011 was announced at the Associationâ&#x20AC;&#x2122;s Annual Conference held in Shoal Bay, NSW. The Sorel Award commemorates Stanislaus Sorel, a French civil engineer, who filed a patent on 10 May 1837 for a method of protecting iron from rust - the parent of the hot dip galvanizing process.

The overall Sorel Award winner for 2011 was Hartway Galvanizers Naval Base, for their work in delivering a hot-dip galvanized solution for a major conveyor module project in the North-West of Australia. Hartway developed a superior engineered solution for protection of the steel

from both damage and corrosion, incorporating exceptional customer service and specialised logistics management to enable a costeffective, on-time, damage free delivery of the product direct to site.

Paul Edmondson, Works Manager of Hartway Galvanizers Naval Base plant said the Sorel Award was a fantastic recognition of the staff at Hartway for identifying an opportunity to provide a solution to the customer that delivered far more value than just the protection of the steel from corrosion. Mr Edmondson also said that now that hot-dip galvanized steel had been proven to be a cost-effective solution for the mining industry in WA, he expected more projects would

take advantage of the capability of the local industry to deliver both solutions and service.

Also receiving high commendations from the judges were two outstanding architectural solutions; Australian Professional Galvanizing for their work on the Futsal Stadium in Cairns, Far North Queensland and Korvest Galvanisers for the Manuele Engineers Head Office in Adelaide, South Australia.

Further details on each of the award winners are available directly from the GAA at www.gaa.com.au or by phone on 03 9654 1266.

Australian Professional Galvanizing: Hot-dip galvanizing provided the perfect tropical solution for the Futsal Stadium in Cairns, Far North Queensland.

Hartway: Conveyor trestle legs up to 23 m in length were hot-dip galvanized for the conveyor modules.

www.corrosion.com.au

Korvest Galvanisers: The Manuele Engineers Head Office with a high quality hot-dip galvanized and paint solution.

Vol 36 No 6 December 2011

13

NEWS

JPCL to honour Rob Francis as an industry top thinker in 2012, and their work will appear throughout the year in JPCL articles.

The Journal of Protective Coatings & Linings (JPCL) has announced the Clive Hare Honors, a unique award that recognises the distinguished achievements of 24 thought leaders worldwide who have advanced the technology of protective and marine coatings in the past decade.

“The designation ‘Top Thinkers’ is reserved for experts who have advanced the protective and marine coatings industry by their words, actions or both during the past decade,” said Harold Hower, founder of JPCL and CEO of Technology Publishing Co.

The Clive Hare Honors also recognises and celebrates the enormous contributions of these individuals throughout the publication’s 28-year history.

Congratulations to ACA member Rob Francis who has made the list of 24 for his research and extensive field experience to challenge the industry’s status quo in critical areas.

The Top Thinker award winners will be profiled in a special issue of JPCL

Hower described a Top Thinker as “first, a writer whose words and ideas have influenced his or her peers.

But Top Thinkers may also create meaningful works in media other than words,” he added.

“We’re thinking of leaders who have organised and motivated their peers to create standards or to organise other meaningful efforts,

such as seminars and symposia to disseminate knowledge about good practice in the technology.”

Hower called the group “both contemplatives and persons of action, writers and leaders—but most distinctively, persons in love with their work and burning with ideas to improve the industry.”

JPCL’s Top Thinkers were selected through a multi-layered process that began with nominations from the publisher and editors of JPCL, industry experts who work closely with JPCL, and SSPC. From the original list of 68 nominees, the committee selected 24 individuals representing most of the different markets and disciplines that JPCL serves.

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Historic WWII Spitfire wreckage arrives in Australia for preservation The Minister for Defence Science and Personnel, Warren Snowdon, has welcomed the arrival of an historic WWII Spitfire aircraft found in northern France in November 2010 to the RAAF Museum at Point Cook, for extensive conservation treatment.

The Spitfire aircraft was flown by Flight Lieutenant Henry ‘Lacy’ Smith from Sydney, NSW, when it was shot down by anti-aircraft fire on 11 June 1944.

“The Spitfire MJ789 crashed into the River Orne, near Caen, in northern France, where it was recovered almost 70 years later,” Mr Snowdon said.

www.corrosion.com.au

“The wreckage of the aircraft will now undergo extensive conservation before being placed on display at the RAAF Museum at Point Cook, Victoria next year.”

"It'll be conserved in its current form and the way we put it on display will tell the story of the RAAF's contribution to the war effort in Europe.

A team of RAAF Museum technical and curatorial personnel will mechanically clean all items of the aircraft, to ensure maximum desalination of the engine and fuselage, a process which is expected to take more than six months.

The conservation effort will involve cleaning the aircraft, then hoisting it into a tank of fresh water for between six and eight months to desalinate it before it is preserved for the long term.

"It looks fairly good for something that's been laid in the salt water since 1944," museum director David Gardner said.

"We've got to get rid of the salt so we can stop the corrosion and corrosion's the biggest killer," Mr Gardner said.

Conserver Gary Walsh works on the Spitfire's Merlin V12 engine. © Commonwealth of Australia and Department of Defence.

Vol 36 No 6 December 2011

15

NEWS

Savcor introduces GIS services for pipeline management Savcor now provides Geographic Information System (GIS) services for the asset management of pipelines and other infrastructure.

GIS is an effective tool for the management and analysis of all the data associated with pipeline management, combining all the information into one easily accessible package.

Sub-metre accuracy GPS surveys (using differential correction) combined with Metrotech pipe locating and depth of cover surveys is overlayed on satellite map imagery and street/regional maps in specialised GIS software to provide the foundation for the GIS. All the data associated with the inspection, maintenance and management of

pipelines is geographically layered onto the map, including linking photographs, reports and other relevant files to features of the pipeline. The software features are extensive and include automated reporting, historical analysis and data queries.

Contact Savcor at sydney@savcor.com for more information.

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16 Corrosion & Materials

• A world leader in protective coatings • Systems proven across the globe • Innovation, quality and performance • Close by – wherever your project is located • Providing a comprehensive technical support function Jotun Australia Pty. Ltd. P.O.Box 105, Altona North, 9 Cawley Road, Brooklyn, Victoria 3025, Australia tel: +61 3 9314 0722 fax: +61 3 9314 0423 email: sales@jotun.com.au www.jotun.com

South Australia Branch Galvanising Site Visit On the Thursday 13th October 2011 Korvest Galvanisers kindly hosted the South Australian ACA members for a Technical Meeting and Site Tour. Steven Evans (General Manager), Peter Freeth (Technical Account Manager) and John Forrest (Production Manager) provided the members with an overview of the galvanising process. They explained the effect of the materials, surface preparation, alloying process and design considerations required to successfully galvanise a product to provide long term corrosion protection. After the presentation the members toured the plant observing the various jigs and hanging devices, pre-treatment dipping tanks and the 14 metre long kettle of liquid zinc at held at 450 degrees. Members witnessed a large ornate gate and a large structural member being galvanised which was exciting to both see, hear and feel. Members were able to get up close and watch as the ash layer was removed from the liquid zinc while the freshly galvanised items were lifted from the kettle. This demonstration was

followed by a tour of the state-of-theart ceramic kettle which has a basket which can spin small items which have be dipped to remove the excess zinc by spinning it. Korvest also provided the members with a show bag containing technical information on the galvanising process,

advantages and a comprehensive CD produced by the Galvanizers Association of Australia. After the tour drinks and nibbles were provided at the Country Comfort Adelaide Manor to provide a networking opportunity which was well received.

Structural sections being extracted from the 14m long kettle at Korvest Galvanisers.

ACA Auckland Division November Meeting Report The Auckland November meeting was held on 2nd November at The Landing Hotel. The speaker was Les Boulton (Principal Consultant, Les Boulton & Associates Ltd) addressing the subject of â&#x20AC;&#x153;Corrosion of building assets â&#x20AC;&#x201C; problems and preventionâ&#x20AC;?.

Les commenced by noting that premature corrosion of building services is sometimes attributed to cost-cutting by the building owner, the building constructor, or the building services designer. Lack of proper maintenance is another contributing factor to building corrosion problems. Also, lack of a

www.corrosion.com.au

proper water management and/or incorrect water pipe commissioning practices in new buildings are factors that have resulted in the initiation of microbiological influenced corrosion (MIC) in building water supply lines.

Another issue highlighted was the practice by building service engineers to specify dissimilar metal contacts in heating, ventilation and air conditioning systems (HVAC) water systems. The performance of HVAC equipment can be compromised from new by the use of dissimilar metal contacts that increase the risk of galvanic corrosion in the plant.

Building owners are often unaware that corrosion control measures are readily available that are a lot more cost-effective than replacing building service equipment that has failed in service due to corrosion. A number of case studies were then presented on corrosion of building assets including HVAC plant. Finally an outline was given of standard industry practices, such as proper materials selection, to avoid corrosion that is too often encountered in building services.

After an extensive Q&A session, ACA Auckland Chairman Michael Williams thanked Les for his presentation.

Vol 36 No 6 December 2011

17

ACA Standards Officer Arthur Austin has prepared a schedule of the latest Standards developments. This report will comprise two parts; a search of SAI Global publications at https://infostore.saiglobal.com/store for new standards, amendments and drafts, and a search for all current publications and standards relating to one of the ACA Technical Groups.

This issue will have a joint focus for the Water & Water Treatment and Welding, Joining & Corrosion groups. Results of the search for each of these can be found in Tables 1 and 2, respectively.

A search of SAI Global at http:// www.saiglobal.com/online/ for new Standards, amendments or drafts

of AS, AS/NZS, EN, ANSI, ASTM, BSI, DIN, ETSI, JSA, NSAI, and Standards and amendments of ISO & IEC published from 10 September to 1 November 2011 was conducted using the following key words and key word groups: durability

cathode or cathodic anode or anodic electrochemical or electrolysis or electroplated corrosion and concrete, or concrete and coatings

corrosion or corrosivity or corrosive; but not anodizing or anodize(d)

The search results showing 37 new Standards Drafts and Amendments can be found in Table 3.

paint or coating; but not anodizing or anodize(d)

A copy of the full report can be downloaded from the ACA’s website www.corrosion.com.au

galvanize or galvanized or galvanizing

Table 1. Title search by publisher with keywords ‘water & waste water & corrosion’ – 6 citations ASTM F1150-06

Standard Specification for Commercial Food Waste Pulper and Waterpress Assembly

DIN 50930-6 (2001-08)

Corrosion behaviour of metallic materials in contact with water - Part 6: Effects on drinking water quality

NACE SP 01 00:2008

Cathodic Protection To Control External Corrosion Of Concrete Pressure Pipelines And Mortarcoated Steel Pipelines For Water Or Waste Water Service

ONORM B 5013-2:1990

Corrosion Protection By Organic Coatings For Water And Waste Water Engineering In Residential Areas; Assessment Of Corrosion Probability And Protection Of Cement-bound Materials

ONORM B 5013-3:1994

Corrosion Protection By Organic Coatings For Water And Waste Engineering In Residential Areas - Testing Of Protective Materials And Requirements

ONORM B 5013-4:1997

Corrosion Protection By Organic Coatings For Water And Waste Water Engineering In Residential Areas - Testing Of Corrosion Protection And Requirements

Table 2. Title search by publisher with keywords ‘welding & corrosion’ – 123 citations AS 2205.10.1-2003

Methods for destructive testing of welds in metal - Corrosion test for welded austenitic stainless steel

To see remaining 122 titles, log on to https://infostore.saiglobal.com/store and enter search phrase “Welding & Corrosion”.

Table 3. New Standards, amendments or drafts for AS, AS/NZS, EN, ANSI, ASTM, BSI, DIN, ETSI, JSA, NSAI and Standards or amendments for ISO & IEC published 10 September – 1 November 2011 Key word search on ‘durability’ - 3 citations found; none from AS or AS/NZS ISO/DIS 16204

Durability - Service life design of concrete structures

11/30238893 DC BS ISO 16204

Durability. Service life design of concrete structures

18 Corrosion & Materials

DIN EN 16014 (2011-10)

Hardware for furniture - Strength and durability of locking mechanisms

Key word search on ‘corrosion’ or ‘corrosivity’ or ‘corrosive’; but not ‘anodizing’ or ‘anodize(d)’- 5 citations found; none from AS or AS/ASNZ ISO 7539-6:2011

Corrosion of metals and alloys - Stress corrosion testing - Part 6: Preparation and use of precracked specimens for tests under constant load or constant displacement

ISO/DIS 16701

Corrosion of metals and alloys - Corrosion in artificial atmosphere - Accelerated corrosion test involving exposure under controlled conditions of humidity cycling and intermittent spraying of a salt solution

ISO/DIS 7539-1

Corrosion of metals and alloys - Stress corrosion testing - Part 1: General guidance on testing procedures

11/30251779 DC BS 6SP 4 AMD3

Pins headed, plain shank, drilled, steel alloy and corrosion resisting steel with a strength class 880/1 080 MPa

DIN EN ISO 10271 (2011-10

Dentistry - Corrosion test methods for metallic materials (ISO 10271:2011)

Key word search on 'paint’ and or ‘coating’; but not ‘anodizing’ or ‘anodize(d)’ or corrosion – 29 publications found; 1 AS or AS/NZS publications AS 1397-2011

Continuous hot-dip metallic coated steel sheet and strip - Coatings of zinc and zinc alloyed with aluminium and magnesium

ISO/FDIS 12670

Thermal spraying - Components with thermally sprayed coatings - Technical supply conditions

ISO/FDIS 13123

Metallic and other inorganic coatings - Test method of cyclic heating for thermal-barrier coatings under temperature gradient

ISO/DIS 13826

Metallic and other inorganic coatings - Determination of thermal conductivity of thermally sprayed ceramic coatings by laser flash

ISO/FDIS 17186

Leather - Physical and mechanical tests - Determination of surface coating thickness

ISO/DIS 9211-4

Optics and photonics - Optical coatings - Part 4: Specific test methods

I.S. EN 16105:2011

Paints and Varnishes - Laboratory Method for Determination of Release of Substances From Coatings in Intermittent Contact With Water

I.S. EN ISO 4628-6:2011

Paints and Varnishes - Evaluation of Degradation of Coatings - Designation of Quantity and Size of Defects, and of Intensity of Uniform Changes in Appearance - Part 6: Assessment of Degree of Chalking by Tape Method (iso 4628-6:2011

11/30208992 DC BS ISO 13826

Metallic and other inorganic coatings. Determination of thermal conductivity of thermally sprayed ceramic coatings by laser flash method

11/30248441 DC BS EN 927-1.

Paints and varnishes. Coating materials and coating systems for exterior wood. Part 1.

Classification and selection

BS EN 16105:2011

Paints and varnishes. Laboratory method for determination of release of substances from coatings in intermittent contact with water

BS EN ISO 4628-6:2011

Paints and varnishes. Evaluation of degradation of coatings. Designation of quantity and size of defects, and of intensity of uniform changes in appearance. Assessment of degree of chalking by tape method

DIN EN ISO 21809-1 (2011-10)

Petroleum and natural gas industries - External coatings for buried or submerged pipelines used in pipeline transportation systems - Part 1: Polyolefin coatings (3-layer PE and 3-layer PP) (ISO 21809-1:2011); English version EN ISO 21809-1:2011

DIN EN ISO 6158 (2011-10)

Metallic and other inorganic coatings - Electrodeposited coatings of chromium for engineering purposes (ISO 6158:2011)

www.corrosion.com.au

Vol 36 No 6 December 2011

19

ACA Standards Update

ISO 12137:2011

Paints and varnishes - Determination of mar resistance

ISO 1518-2:2011

Paints and varnishes - Determination of scratch resistance - Part 2: Variable-loading method

ISO/FDIS 11127-1

Preparation of steel substrates before application of paints and related products - Test methods for non-metallic blast-cleaning abrasives - Part 1: Sampling

ISO/FDIS 11127-2

Preparation of steel substrates before application of paints and related products - Test methods for non-metallic blast-cleaning abrasives - Part 2: Determination of particle size distribution

ISO/FDIS 11127-3

Preparation of steel substrates before application of paints and related products - Test methods for non-metallic blast-cleaning abrasives - Part 3: Determination of apparent density

ISO/FDIS 11127-4

Preparation of steel substrates before application of paints and related products - Test methods for non-metallic blast-cleaning abrasives - Part 4: Assessment of hardness by a glass slide test

ISO/FDIS 11127-5

Preparation of steel substrates before application of paints and related products - Test methods for non-metallic blast-cleaning abrasives - Part 5: Determination of moisture

ISO/FDIS 11127-6

Preparation of steel substrates before application of paints and related products - Test methods for non-metallic blast-cleaning abrasives - Part 6: Determination of water-soluble contaminants by conductivity measurement

ISO/FDIS 11127-7

Preparation of steel substrates before application of paints and related products - Test methods for non-metallic blast-cleaning abrasives - Part 7: Determination of water-soluble chlorides

I.S. EN 16105:2011

Paints and Varnishes - Laboratory Method for Determination of Release of Substances From Coatings in Intermittent Contact With Water

I.S. EN ISO 4628-6:2011

Paints and Varnishes - Evaluation of Degradation of Coatings - Designation of Quantity and Size of Defects, and of Intensity of Uniform Changes in Appearance - Part 6: Assessment of Degree of Chalking by Tape Method (iso 4628-6:2011)

11/30229688 DC BS EN ISO 1524

Paints, varnishes and printing inks. Determination of fineness of grind

11/30248441 DC BS EN 927-1

Paints and varnishes. Coating materials and coating systems for exterior wood. Part 1.

Classification and selection

BS EN 16105:2011

Paints and varnishes. Laboratory method for determination of release of substances from coatings in intermittent contact with water

BS EN ISO 4628-6:2011

Paints and varnishes. Evaluation of degradation of coatings. Designation of quantity and size of defects, and of intensity of uniform changes in appearance. Assessment of degree of chalking by tape method

Key word search on 'galvanize' or ‘galvanized’ or galvanizing’ – 0 Standards publications found.

Key word search on 'corrosion' and 'concrete' or ‘concrete’ and ‘coatings’ – 0 Standards publications found Key word search on ‘cathode’ or 'cathodic' – 0 Standards publications found Key word search on 'anode' or ‘anodes’ or ‘anodic’ – 0 Standards publications found – None from AS/ANZS Keyword Search on 'electrochemical' or ‘electrolysis’ or ‘electroplated’ – 0 Standards publications found Keyword Search on 'anodize' or ‘anodized’ – 0 Standards publications found

20 Corrosion & Materials

University Profile Deakin University Our people

Professor Maria Forsyth ARC Laureate Fellow, Chair in Electromaterial & Corrosion Science Major research areas: Chemical methods for corrosion inhibition and surface pretreatment (including novel ionic liquids) Corrosion of light metals (Mg & Al) Advanced electrochemical and surface characterisation techniques in corrosion applications phone: +61 3 924 46821 email: maria.forsyth@deakin.edu.au Although Deakin has had a long involvement in corrosion activities, its major programs in corrosion research and teaching were initiated by the recent appointment of Professor Maria Forsyth as Chair in Electromaterials & Corrosion Sciences in August 2010. Professor Forsyth has been recognised as one of Australia’s leading researchers through a prestigious national award, an Australian Laureate Fellowship, that is awarded by the Australian Research Council and supports outstanding research leaders in solving the world’s biggest problems and passing on their skills to the next generation of researchers. Professor Forsyth has a diverse range of research interests and leads a team focusing on the areas of Energy Storage and Corrosion Mitigation. In particular her team are at the forefront of

www.corrosion.com.au

developing new materials, advanced characterisation tools and supporting innovative technologies in these two fields. For example Professor Forsyth and her team have been developing and characterising new environmentally friendly methods to control charge transfer at reactive metal interfaces such as aluminium and magnesium; her group have pioneered the development of novel corrosion inhibitors based on rare earth metal-organic compounds and more recently the use of Ionic Liquid pre-treatments. The team’s work has been well recognised through many invitations to present their work at prestigious international conferences.

Professor Forsyth is passionate about education and in particular relating to areas of national and international significance such as sustainability and clean energy. Many of Professor Forsyth’s past students from her previous position at Monash University are now themselves in leadership positions either in academia or industry.

Professor Hodgson was also honoured with an ARC Australian Laureate Fellowship in 2009 reflecting his leadership in the area of Metallurgy and Materials Engineering. One of the first ARC Laureate’s announced and the first in any Victorian University, Professor Hodgson's research includes steel processing and the development of new alloys, and downstream ferrous and nonferrous manufacturing processes associated with the automotive industry. He currently holds several ARC Discovery and Linkage grants, all related to metal processing. In 2004 he was made an Alfred Deakin Professor of the University for outstanding contributions to research and awarded an ARC Federation Fellowship by the Australian Research Council. The University of Valenciennes award made him an Honoris Doctoris Causa in 2005 for contributions to metal forming research, while in 2006 AGH in Poland awarded him an Honorary Medal for contributions to materials science.

Peter is also very strongly connected to industry and solution to real world problems having himself come from a leadership position in BHP steel.

Professor Peter Hodgson ARC Laureate Fellow Director Institute of Technology and Research Innovation Major research areas: Metallurgy and materials Development of new alloys Light weighting and Sustainability email: peter.hodgson@deakin.edu.au

Adjunct Professor Bruce Hinton Major research areas: Corrosion inhibition Stress Corrosion Cracking (SCC) Corrosion fatigue and hydrogen embrittlement email: bruce.hinton@deakin.edu.au

Vol 36 No 6 December 2011

21

University Profile

Deakin University is privileged to have Professor Bruce Hinton as an adjunct professor in the Institute of Technology and Research Innovation. He works closely with Professor Forsythâ&#x20AC;&#x2122;s team and co-supervisors several Deakin students. Professor Hinton graduated from the Department of Mining and Metallurgical Engineering at the University of Queensland in 1968. He joined Aeronautical Research Laboratories at Fishermens Bend in Melbourne in 1969 and was a Principal Research Scientist and Head of the Aircraft Corrosion Control Group at the Aeronautical and Maritime Research Laboratory in Melbourne.

Bruce has been involved for over 30 years in research and problem solving in the field of corrosion prevention and control in aircraft structures. He has co-authored 3 Patents and delivered and published numerous papers over his career.

He has received many awards over the past 25 years including best paper awards, IMMA Florence Taylor Medal, ACA Corrosion Medal and the 2009 Frank Newman Speller Award. One of the most significant contributions made by Bruce and his research team at DSTO was their pioneering use of preventative compounds for treating existing corrosion, saving many maintenance hours, decreasing aircraft downtime and contributing to overall aircraft safety. Since Bruce officially retired from DSTO he has become part of the Deakin University Corrosion team as well as contributing to corrosion research at Monash University and CSIRO. His passion for understanding corrosion processes and methods to control corrosion is infectious and a great asset for all students and younger researchers with whom he has contact.

22 Corrosion & Materials

Assoc. Professor Mike Yongjun Tan Major research areas: Corrosion testing and monitoring techniques Electrochemical corrosion methods Localised corrosion and its measurement Corrosion inhibitor testing and development

and has authored/co-authored some 30 journal articles related to this area of research. Associate Professor Tan has also taught and coordinated undergraduate, postgraduate and industrial corrosion engineering courses. In addition to his academic research and teaching career, he worked on industry consultancy and commercialisation projects and contributed to some 30 industry R&D and consultancy reports. One contribution was the development of a high performance thin-film rustproof-lubricating oil as a leading researcher. After an extensive peer-review process, Dr Tan has been awarded a publication contract from John Wiley & Sons to author a 350 page research book entitled 'Heterogeneous Electrode Processes and Localised Corrosion'.

email: mike.tan@deakin.edu.au The most recent addition to the Deakin University Corrosion team is Associate Professor Mike Tan. He is appointed within ITRI and the School of Engineering as an Associate Professor in Applied Electrochemistry and Corrosion Technologies. Mike has been an active researcher in the fields of Corrosion and Applied Electrochemistry during the past 20 years. Over his career thus far, he has made three major contributions to electrochemistry and corrosion research: (i) the invention of the wire beam electrode (WBE) method and development of a localised corrosion probe (US patent No.6132593). This method, or other similar methods, has been utilised by at least 20 R&D groups around the world. He has authored/co-authored some 40 refereed journal articles to report continued advancements in the WBE technology. (ii) contributed to electrochemical noise analysis techniques, proposed the statistical linear polarisation theory to explain electrochemical noise resistance and extended the application of this method. (iii) contributed to understanding of noise signatures

Dr. Patrick Howlett Senior Lecturer, ITRI Major research areas: Ionic Liquid treatments of reactive metal surfaces Advanced electrochemical and surface characterisation email:Patrick.howlett@deakin.edu.au Dr. Howlett is an applied electrochemist with research interests in Energy Storage and novel chemical pretreatment of metals surfaces to improve corrosion resistance of engineering alloys. He is also involved in the development of in-situ advanced characterisation methods based on Synchrotron techniques. continued overâ&#x20AC;Ś

Other senior staff with corrosion interests: Dr. Marianne Seter (inhibitor research and MIC) Dr. Jim Efthimiadis & Dr. Paul Collins (Industry liaisons) Dr. Angel Torreiro (ionic liquids and electrochemistry) Mr. Anthony Somers (advanced surface characterisation and tribology) Prof. Matthew Barnett (light alloy development) Our current research and future directions The School of Engineering at Deakin University is currently implementing new course structures and facilities under the “Infrastructure Theme” – an area in which it is already building a reputation – and sitting inside this will be a strong corrosion and reliability engineering element. This will be a strong contributor to the education of the next generation of corrosion and maintenance engineers for Australia and its development will be guided in partnership with major industries both locally in Australia and internationally.

science and engineering with particular emphasis at present in the following areas: Development of new corrosion inhibitors and novel surface treatments for application in various industrial environments including defence, oil and gas, aerospace.

Development of innovative corrosion testing and monitoring techniques, with particular focus on localised corrosion detection and prediction, and their applications.

Understanding critical corrosion processes in the desalination industry and developing smart new materials and monitoring techniques which will lead to greater reliability and cost savings for this industry.

Understanding critical corrosion processes in the oil & gas production and refinery industries and developingof new technologies for the prediction and prevention of these.

Development of new technologies for the prediction and prevention of corrosion in marine environments, with particular focus on defence equipment.

Research facilities and related research capabilities at Deakin University Our Research Facilities Corrosion research at Deakin University is supported by various state of the art testing and characterisation facilities. Surface characterisation equipment including scanning electron microscopes, Optical Profilometry, ATR-FTIR spectroscopy are available in Research Centres within the Institute for Technology Research and Innovation (ITRI). Advanced electrochemical facilities include several multichannel potentiostats, a scanning electrochemical microscopy, electrochemical impedance and electrochemical noise instruments and a multielectrode array system (WBE instrument). The team is also well equipped with general corrosion testing facilities including autoclaves and pressure vessels. Deakin is in the process of further expanding it facilities for corrosion research with recent appointments.

ITRI Deakin

Deakin University continues to grow its research activity in corrosion

www.corrosion.com.au

Vol 36 No 6 December 2011

23

LL FOLD

BACK COVER FRONT COVER The Australasia

Application pro

cedure

n Corrosion Ass

A completed application form with accompa payment and nying documentatio n should be sent ACA Certifica to tion Scheme, PO Box 112, Kerr the VIC 3129 or faxe imuir d to +61 3 9890 7866.

Your applicati on will be initia lly assessed and you will be cont acted if any furth required. The er information ACA will cont is act your referees then forward and your applicati on to the Cert Review Board ification (which meets periodically every 3 months) approx for assessment. contacted by You may be the ACA or one of the Certifica Review Board tion members if furth er information needed to prop is erly assess your application. Once reviewed, you will receive notifi cation by lette the Certification r as to Review Board’s decision.

For further infor mation on the Certification Application Form Rules, or the Complain please visit our ts Process, website at www .corrosion.co or call the ACA m on +61 3 9890 4833.

Corrosion Technicians

brochure which is available on our website www.corrosion.com.au. A schedule of current ACA Corrosion Technicians and Technologists appears below and will be published in Corrosion & Materials in full each April and Affect on ACA Membership December and will be continuously updated on the ACA’s web site. All current ACA Technicians and Technologists have been issued a wallet 98mmcertification number and card with their 99mm membership details.

N PROGRAM

The ACA’s Certification program for ACA Corrosion Technicians and Technologists recognises those with education and experience in the corrosion industry. A Corrosion Technician has at least 4 years work experience and has attended a number of formal training courses, whilst those awarded Corrosion Technologist have at least 10 years work experience and have obtained further training. For a more detailed explanation of the eligibility criteria, please consult our ACA Certification Program

CERTIFICATIO

Work experie nce and work in responsibl e charge

Work experien ce in corrosio n or corrosio related field is n defined as prac tical experien in corrosion mec ce hanisms, caus es, control and monitoring. It covers the inve stigation, desi implementat gn or ion of corrosio n control. The must be tech work nical in nature (not sales for and in the corr example) osion field. Meta llurgy, welding inspection, Non Destructive Test are not acceptab ing (NDT) etc, le, except whe n directly rela to corrosion. ted Work in responsi ble charge in corrosion or a corrosion rela ted field is, work experience as above, which defined includes a leve l of responsibility requiring tech nical judgeme nt. The applican must be in tech t nical control and have tech responsibility nical . Work such as desi and failure anal gn, specification, ysis etc are cons idered responsi work in charge, ble as opposed to routine testing application of or corrosion cont rol measures, or installing anod ie painting es.

Working toward Professional De velopment in Corrosion

ACA Certified Corrosion Technologists and Technicians

ACA accredita tion as a Corr osion Technologist will have no affec Technician/ t on a member’s privileges inclu ding their righ t to vote, hold office or part any icipate in any associated activ ity.

100mm

Derek Avery

295

19/08/2012

Name

Cert No:

Expiry Date

Dinesh Bankar

264

22/02/2012

Gary Barber

248

30/06/2012

Dinesh Bankar

264

22/02/2012

Stephen Brown

263

4/02/2012

Don Bartlett

15

29/06/2012

Thomas Byrne

91

14/07/2012

Stuart Bayliss

236

7/11/2012

Dave Charters

261

21/01/2012

Peter Beckford

187

28/02/2012

Pasquale Chiaravalloti

274

6/06/2012

Tony Betts

74

1/01/2013

Rodney Clarke

206

20/12/2011

Rob Billing

12

30/06/2012

Craig Clarke

246

26/03/2012

Harvey David Blackburn

10

1/01/2013

Ross Darrigan

174

14/07/2012

Michael Boardman

30

12/07/2012

Glenn Dean

280

20/01/2012

Les Boulton

43

1/01/2013

David Fairfull

179

30/06/2012

John Bristow

107

1/01/2013

Geoff Farrant

253

30/06/2012

Gary Brockett

215

30/06/2012

Robert Gentry

114

30/06/2012

Kingsley Brown

257

27/09/2012

David Harley

291

30/06/2012

Philip Bundy

209

30/06/2012

Stephen Holt

207

28/02/2012

Wayne Burns

100

1/01/2013

Bradley Jones

258

18/04/2012

Brian Byrne

27

1/01/2013

Boris Krizman

169

18/02/2012

Bryan Cackett

70

30/06/2012

Gary Martin

57

1/06/2012

Robert Callant

103

30/06/2012

Ian McNair

163

30/06/2012

Neil Campbell

38

30/06/2012

Terence Michael Moore

125

9/06/2012

Graham Robert Carlisle

281

17/11/2012

David Morgan

234

16/02/2012

Antonio Carnovale

203

30/06/2012

Reg Oliver

223

30/06/2012

Luis Carro

260

30/06/2012

David Parravicini

296

2/09/2012

Reg Casling

11

1/01/2013

Rafael Pelli

164

30/06/2012

Dylan Cawley

224

29/06/2012

Keith Perry

139

31/01/2012

Ian Clark

255

30/06/2012

Sean Ryder

262

21/11/2012

Peter Clark

80

30/06/2012

Ian Saunders

251

24/06/2012

Stan Collins

128

30/06/2012

Brian Smallridge

201

30/06/2012

Geoff Cope

71

29/06/2012

Justin Tanti

238

14/02/2012

Leon Cordewener

44

30/06/2012

Gavin Telford

244

30/06/2012

Robert Cox

14

30/06/2012

John Tomlinson

53

28/02/2012

Peter Crampton

8

29/06/2012

Mark Watson

186

30/06/2012

Kerry Dalzell

28

30/06/2012

Derek Whitcombe

123

30/06/2012

Corrosion Technologists

Roman Dankiw

208

29/06/2012

Rene D'Ath

197

11/03/2012

Name

Cert No:

Expiry Date

Robert de Graaf

154

14/07/2012

Bruce Ackland

82

30/06/2012

Mike Dinon

5

30/06/2012

Fred Andrews-Phaedonos

153

30/06/2012

Bradley Dockrill

241

15/07/2012

Ross Antunovich

214

30/06/2012

Peter Dove

210

29/03/2012

Arthur Austin

106

30/06/2012

Gary Doyle

294

2/08/2012

Adrian Dundas

250

1/02/2012

24 Corrosion & Materials

ociation Inc

CERTIFICATION PROGRAM

Working toward Professional Development in Corrosion Lucas Edwards

273

6/06/2012

John Mitchell

115

30/06/2012

Bernard Egan

20

30/06/2012

Elio Monzu

159

30/06/2012

Gary Evans

271

30/06/2012

Greg Moore

97

1/01/2013

Wayne Ferguson

242

4/09/2012

Janet Morris

256

5/07/2012

Peter Ferris

195

30/06/2012

Robert Mumford

33

30/06/2012

Gavin Forrester

282

10/02/2012

Tony Murray

134

30/06/2012

Rob Francis

23

29/06/2012

David Nicholas

94

1/01/2013

Dale Franke

199

30/06/2012

Calvin Ogilvie

17

19/01/2012

Max Fraser

283

17/03/2012

Dean Parker

108

5/07/2012

Robert Freedman

147

1/01/2013

David Pettigrew

297

17/12/2011

Jim Galanos

254

17/12/2011

Steve Richards

110

30/06/2012

Barry Gartner

2

30/06/2012

Dennis Richards

180

1/01/2013

Gavin Richardson

48

30/06/2012

Bill Gerritsen

18

30/06/2012

Ian Glover

129

30/06/2012

Tony Ridgers

36

30/06/2012

Frederick Gooder

141

30/06/2012

Geoff Rippingale

37

30/06/2012

Chris Hargreaves

292

26/07/2012

Geoff Robb

124

30/06/2012

Phil Harrison

145

8/05/2012

Bernd Rose

252

1/05/2012

Peter Hart

200

30/06/2012

John Rudd

243

21/06/2012

Frank Hewitt

67

1/01/2013

Fred Salome

231

1/01/2013

Brian Hickinbottom

138

30/06/2012

Ian Savage

259

30/06/2012

Brett Hollis

88

30/06/2012

Ron Scaddan

272

5/02/2012

Marshall Holmes

293

25/08/2012

Philip Schembri

198

30/06/2012

Peter Hosford

216

1/01/2013

D. Paul Schweinsberg

34

1/01/2013

David Scott

173

29/06/2012

Paul Hunter

62

30/06/2012

Jeffrey Hurst

202

30/06/2012

Mike Slade

175

7/06/2012

Craig Hutchinson

249

26/10/2012

Jim Steele

119

17/12/2011

Luciano Ioan

228

6/06/2012

Alan Steinicke

9

1/06/2012

Bruce Jewell

245

30/06/2012

Allan Sterling

191

31/03/2012

Michael Johnstone

230

18/04/2012

Ian Stewart

155

18/06/2012

Michael Jukes

90

3/03/2012

Gordon Stewart

68

1/01/2013

John Kalis

166

17/12/2011

Graham Sussex

136

30/06/2012

Graeme Kelly

102

1/01/2013

Tan Swee Hain

189

30/06/2012

John Kilby

193

30/06/2012

Yongjun (Mike) Jun Tan

194

30/06/2012

John Barry Lane

188

30/06/2012

Peter Thorpe

144

1/01/2013

Peter Tomlin

120

30/06/2012

Bill Lannen

111

1/01/2013

Harry Lee

19

30/06/2012

Nicholas Van Styn

229

25/02/2012

Keith Lichti

133

30/06/2012

Peter Wade

190

30/06/2012

Verne Linkhorn

39

30/06/2012

Brian Walter Walsh

157

14/02/2012

Garry Luskan

117

2/02/2012

John Waters

121

30/06/2012

Willie Mandeno

13

30/06/2012

John Watson

239

10/06/2012

Brian Martin

60

1/01/2013

Richard Webster

69

30/06/2012

William McCaffrey

142

30/06/2012

Mark Weston

149

1/01/2013

John McCallum

59

30/06/2012

Geoffrey R White

182

1/07/2012

Daryl McCormick

1

17/12/2011

Paul Ashleigh Wilson

290

19/04/2012

Murry McCormick

196

28/06/2012

Rodney Wubben

46

30/06/2012

Morris Young

217

30/06/2012

Michael McCoy

109

14/04/2012

Brad McCoy

178

14/07/2012

Bill McEwan

32

1/01/2013

Vic McLean

237

30/06/2012

Jim McMonagle

56

1/01/2013

www.corrosion.com.au

List current at time of printing

Vol 36 No 6 December 2011

25

Major sponsor:

Proudly presented by:

corrosion & prevention

Corrosion Management for a Sustainable World: Transport, Energy, Mining, Life Extension and Modelling Crown Conference Centre • Melbourne, Victoria, Australia • 11–14 November 2012

First Announcement & Call for Papers Call for Papers

The Destination

Submissions are now welcome on all aspects of corrosion and corrosion control for Corrosion & Prevention 2012.

Papers are subject to peer review and if accepted will be published in the Conference Proceedings. Critical dates for acceptance of abstracts and papers are:

Consistently voted one of the world’s most livable cities, Melbourne is a lively and cosmopolitan city that combines a fanatical love for the creative arts and good living with a state-wide sports addiction to make a city like no other. Set around the shores of Port Phillip Bay, the central business district is located on the northern banks of the picturesque Yarra River.

Close of Abstracts: 30th March 2012 Acceptance of Abstracts: 13th April 2012 Receipt of Papers: 29th June 2012

Submit an Abstract Please refer to www.corrosion.com.au to submit a 200-300 word summary of your proposed paper by the close of abstracts (30th March 2012).

Waldron Smith Management, a professional conference management company based in Melbourne will be managing the abstract and paper submission process for Corrosion & Prevention 2012.

Guide to Submission Papers submitted to the Corrosion & Prevention 2012 Conference must be unpublished works. It is the responsibility of the author to obtain necessary clearance/permission from their organisation. Copyright of the paper is assigned to the ACA. Abstracts should include the names of all authors, an appropriate title and a brief summary. All authors whose papers are accepted are required to attend the conference to present.

But it is within Melbourne’s hidden laneways where the city truly comes to life, where mainstream culture takes a back seat to allow for one-off boutiques, unique galleries, tiny cafés and hidden bars. With an eclectic dining scene that offers a startling array of the world’s great cuisines, from popular favourites to the truly ground breaking.

Although Melbourne is celebrated as Australia’s home to the arts, sport and shopping, just one hour’s drive from the city takes you a world away from the urban frenzy.

With destinations like the Yarra Valley, The Great Ocean Road and Victoria’s Goldfields region you can take your pick from 100 local vineyards, rest and relax at award winning day spas, tee off at world class golf courses or even enjoy a swim with the dolphins.

Melbourne is a creative, exciting, ever-changing city with extraordinary surprises to be discovered in every basement, rooftop and laneway. The possibilities are endless, so forget what you think you know. Take a chance, lose yourself in Melbourne.

Conference Convenor Technical Topics Papers for the Conference are expected to cover a wide range of topics relating to all aspects of the corrosion industry. This will span the spectrum of fundamental research and science, to large-scale engineering and industrial implementation of corrosion technology. This will include an understanding of corrosion mechanisms, corrosion prevention, and management of corrosion issues, along with computational and modelling aspects. The following topics will be considered: Corrosion Science and Research Corrosion Engineering and Industrial Implementation Corrosion Modelling Case Studies Corrosion in Energy Systems and Distribution Networks Contractor Perspectives Advances in Corrosion Prevention and Cathodic Protection Corrosion Management Protective Coatings

Industry Sectors This conference will have material of value to those working within the following industries: Civil Infrastructure Defence Mining Oil and Gas Energy Transmission Education and Research Power Water Manufacturing Maintenance Government Transport

Ian Godson

Technical Chairs Nick Birbilis Bruce Hinton Neil Campbell

Committee Peter Dove Sarah Furman Dean Ferguson

Sponsorship and Exhibition Sponsorship will enable your company to make a significant contribution towards the success of Corrosion & Prevention 2012. In return, the conference offers strong branding and exposure in a focussed and professional environment. As with every Conference, the exhibition will be an integral part of the activities.

It provides an opportunity for organisations to come face to face with the delegates; providing a marketplace to increase your organisationâ&#x20AC;&#x2122;s visibility and to showcase and demonstrate your products and services.

For further information, please contact the Australasian Corrosion Association on +61 (0)3 9890 4833 or conference@corrosion.com.au

Your Hosts The Australasian Corrosion Association Incorporated (ACA) is a not-for-profit, industry association, established in 1955 to service the needs of Australian and New Zealand companies, organisations and individuals involved in the fight against corrosion.

The mission of the ACA is to promote the co-operation of academic, industrial, commercial and governmental organisations in relation to corrosion and its mitigation and for disseminating information on all aspects of corrosion and its prevention by promoting lectures, symposia, publications and other activities.

ACA Centre

Marine Engineering

PO Box 112 Kerrimuir, Victoria, Australia, 3129

Materials Engineering

Ph: +61 3 9890 4833, Fax: +61 3 9890 7866,

Coating Inspection and Surveillance

Email: conference@corrosion.com.au Website: www.corrosion.com.au

Asset Managers, Corrosion Specialists and Consultants

ACA Corporate Members CORPORATE PLATINUM 3C Corrosion Control Company

International Protective Coatings

AECOM Australia Pty Ltd

Jemena

Asset Facility Management Pty Ltd

Jotun Australia Pty Ltd

Australasian Industrial Wrappings & Coatings Pty Ltd

PPG Industries Australia Pty Ltd

Bureau Veritas Asset Integrity & Reliability Services Pty Ltd

SA Water Corporation

Corrosion Control Engineering Pty Ltd

Santos Limited

Denso (Australia) Pty Ltd

Savcor ART Pty Ltd

Dulux Australia

Watercare Services Ltd

Hempel (Australia) Pty Ltd

Wattyl Australia

Incospec & Associates Australia Pty Ltd

Zintec Corrosion Solutions

CORPORATE GOLD A & E Systems Pty Ltd

Newcastle Port Corporation

ALS Industrial Pty Ltd

North Australian Centre For Oil & Gas

Australian Tank Maintenance

ORONTIDE

Central Systems Pty Ltd

Peerless Industrial Systems

Century Yuasa Batteries Pty Ltd

Quest Integrity

Core Group Ltd

SMEC Australia Pty Ltd

Eptec Pty Ltd

Steuler Industrial Corrosion Protection

GHD Pty Ltd

Tarong Energy Corp Ltd

GMA Garnet Pty Ltd

TBS Corporation

CORPORATE SILVER Action Alliance Group

Olympus Australia

Altex Coatings Ltd

Opus International Consultants Ltd

Anode Engineering Pty Ltd

Petro Coating Systems Pty Ltd

Applus RTD Pty Ltd

Rhino Linings Australasia Pty Ltd

Arup Pty Ltd

RKF Engineering Services

Australian Pipeline Trust Management Services Pty Ltd

Rosen Australia Pty Ltd

Baker Hughes Australia Pty Limited

RPG Australia

Cape - Australia

Scientific Solutions Pty Ltd

CTI Consultants Pty Ltd

South Coast Surface Protection

Curtin University of Technology

Specialised Pipe Spooling Pty Ltd

Engineered Surface Preparation

Telstra Corporation

Extrin Consultants

Transpacific Industrial Solutions

Favcote Pty Ltd

Veolia Environmental Services

Geopave/Vic Roads

Vinsi Partners Pty Limited

Hydro-Chem Pty Ltd

Wood Group Integrity Management

Kaefer Novacoat (WA) Pty Ltd

Worley Parsons Ltd

Melbourne Water

28 Corrosion & Materials

List accurate at 7/11/11

CORPORATE BRONZE A S Harrison & Co Pty Ltd AB and P Abrasive Blasting & Painting ABSAFE Pty Ltd ACTEW AGL Distribution Action Painters Auckland (2007) Ltd Adtech FRP Pty Ltd Advanced Aqua Blasting Airservices Australia Albany Port Authority Alfabs Protective Coatings Pty Ltd Alloy Yachts International Ltd Allunga Exposure Laboratory AmaC Corrosion Protection Pty Ltd AP Kempe Engineering APA GasNet OPS Pty Ltd APT AM Holdings Pty Ltd ARC West Group Pty Ltd Armor Galv ASC Pty Ltd Asset Integrity Australasia Pty Ltd ATTAR Aurecon Australia Pty Ltd Aurecon PPI Aurora Energy Ausblast Auscor Pty Ltd Austral Wright Metals Australian Maritime College Australian National Maritime Museum Australian Paper Manufacturers Bachalani Constructions Pty Ltd BAE Systems Australia BASF Australia Ltd Bayer Material Science Pty Ltd BCMG Pty Ltd BCRC (NSW) Pty Ltd Bianco Structural Steel Blastcorp Pty Ltd BP Refinery (Bulwer Island) BP Refinery (Kwinana) Pty Ltd BRANZ Limited Bredero Shaw Australia Pty Ltd Brisbane Abrasive Blasting Buel Pty Ltd Bundaberg Sandblasting Pty Ltd Caltex Australia Petroleum Pty Ltd Caltex Refineries (QLD) Ltd Cameleon Paints Cameron Applied Research and Developments Pty Ltd Cathodic Diecasting (QLD) Pty Ltd CEA Australia Pty Ltd CEM International Pty Ltd Centreport Limited Champion Technologies Chevron Australia Pty Ltd Chiron Chemicals City West Water Clarkes Painting Services Clavon Pte Ltd Commercial Industrial Painting Services Pty Ltd Contract Resources Pty Ltd www.corrosion.com.au

CORE Water Management Solutions Pty Ltd Corrocoat Engineering (Aust) Pty Ltd Corrosion Electronics Pty Ltd Corrosion Specialists Pty Ltd Costin Roe Consulting Couplertec Electronic Rustproofing Cox Coating Pty Ltd Cradle Mountain Water Crest Restoration Services Pty Ltd Department of Transport and Main Roads Dept of Infrastructure, Energy & Resources Dept of Planning and Infrastructure Diagnostech Pty Ltd Dimet Anti-Corrosion Pty Ltd Doito Pty Ltd Dukes Painting Services Pty Ltd Duratec Australia Pty Ltd EM&I (Australia) Pty Ltd Energex Ltd Energy Safe Victoria Energyworks Ltd Esso Australia Ltd Firma Industries Fremantle Ports Fremantle Sailing Club Freyssinet Australia Pty Ltd Galvanizers Association of Australia Ganellen Asset Services Germanischer Lloyd (Australia) Pty Limited Giovenco Industries (Aust) Pty Ltd Gippsland Cathodic Protection Gippsland Water Gladstone Ports Corporation Ltd GORODOK Pty Ltd GPR Electrical (WA) Pty Ltd Grange Resources (Tasmania) Pty Ltd Greater Wellington Regional Council Halcrow Group Limited Hamersley Iron Pty Ltd HERA Holmes Consulting Group Horiso Pty Ltd Hunter Water Australia Pty Ltd Hydro Flow Pty Ltd Hydro Tasmania idec Protective Coatings Pty Ltd Industrial Composite Contractors Industrial Galvanizers Pty Ltd Innovative Corrosion Management Pty Ltd Inspection & Consultancy Services Ltd International Corrosion Services Pty Ltd Invensys Rail Pty Ltd Ionode Pty Ltd IPCQ ITW AAMTECH ITW Buildex Jacobsen Colourplus Ltd Keppel Prince Engineering Pty Ltd KGB Protective Coatings Korvest Ltd - Galvanising Division Kulin Group Pty Ltd Linetech Consulting LinkWater

Liquigas Ltd Longmont Engineering Lordco NZ Ltd Lothway-TBS Pty Ltd Loy Yang Power Ltd Lyttelton Port of Christchurch M Brodribb Pty Ltd M Waters Abrasive Blasting Services Mahaffey Associates Pty Ltd Maintenance Systems Pty Ltd Marden Corrosion Services P/L McCoy Engineering Pty Ltd McElligott Partners Pty Ltd McElligotts (Tas) Pty Ltd McKechnie Aluminium Solutions Limited Metal Spray Suppliers (NZ) Ltd Methanex New Zealand Ltd Metrocorp Technologies Metz Specialty Materials Pty Ltd Mills Sign & Painting Service Mobil Refining Australia Pty Ltd (Altona Refinery) MTK Consulting Nalco Australia Pty Ltd Nanmah Pty Ltd NDT Equipment Sales Pty Ltd New Zealand Aluminium Smelters New Zealand Steel Ltd Newcastle City Council NMT Electrodes (Australia) Pty Ltd Norblast Industrial Solutions Pty Ltd North Queensland and Bulk Ports Corporation Northport Ltd NPC Industries Pty Ltd NZ Refining Co Ltd Origin Energy Orrcon Operations Pty Ltd Osborne Cogeneration Outokumpu Pty Ltd Pacific Resins Pty Ltd Paint N Colour Parchem Construction Supplies PCCS Trust PCWI International Pty Ltd Phillro Industries Pty Ltd Polymer Group Ltd Port Kembla Port Corporation PPG Performance Coatings (M) Sdn Bhd Prendos New Zealand Ltd Preservation Technologies Primary Industries & Resources of South Australia Pro-Fast Protective Coatings Prokote Pty Ltd Pumpline Pty Ltd QLD Dept Main Roads - Structures Division QLD Painters & Maintenance Services Pty Ltd Queensland Alumina Ltd Queensland Nickel Pty Ltd Queensland Sugar Limited Queensland Urban Utilities

Rail Corporation Reinforced Earth Pty Ltd Rema Tip Top Industrial Pty Ltd Reno Blast Resene Paints Ltd Rheem Australia Pty Ltd Rightway Industrial Pty Ltd RM Watson Pty Ltd Roads & Traffic Authority of NSW RTA Weipa Pty Ltd Rust-oleum Industrial Coatings Sea Coatings Australia Pty Limited SGS NZ Ltd Shell Refining Australia Shoreguard Marine Sika (NZ) Ltd Sika Australia Silver Raven Pty Ltd SLH Contracting (2008) Ltd South East Water Limited Special Metals Pacific Pte Ltd Stanwell Corporation Structural Systems (Remedial) Pty Ltd Subspection Pte Ltd Sulco Limited Summit Fertilizers SunWater Limited SVT Engineering Consultants Syntech Distributors Ltd TAFE NSW - Sydney Institute Tandex Pty Ltd Tas Gas Networks Tas Protective Coatings Tasmanian Ports Corporation Pty Ltd The Valspar (Australia) Corporation Pty Limited Thomas Contracting Pty Ltd ThyssenKrupp VDM Australia Pty Ltd Titanium Anode Corporation Pty Ltd Titanium Electrode Products (Australia) Pty Ltd Total Corrosion Control Total Paint Protection Total Surface Protection Townsville Port Authority Transcote Pty Ltd Transend Networks Pty Ltd Transfield Services Transpower New Zealand Ltd Tri-Star Industries Pte Ltd Tropical Reef Shipyard Pty Ltd Tyco FCP Tyco Water Technologies Undersea Construction Ltd Valicote Pty Ltd Vector Gas Limited WAG Pipeline Proprietary Ltd Wannon Region Water Corporation Water Corporation of Western Australia Willall Industries Pty Ltd Woodside Energy Ltd Yarra Valley Water

Vol 36 No 6 December 2011

29

Cathodic Protection of a 1.2km long Harbour Tunnel A 1.2km long 4.35m diameter crossharbour tunnel was constructed in 1996 for an iron ore conveyor. This used 5,154 reinforced concrete lining segments bolted together by mild steel bolts located within bolt pockets. Since early in its construction the tunnel experienced seawater leakage through segment seals and grout ports. Due to the water pressure, leakage of tunnels under a harbour is not uncommon and regular wash down and maintenance would be required.

However, with a conveyor that operates continuously, it is only possible to undertake minimal maintenance. Over time saltwater ingress caused severe corrosion of the exposed mild steel bolt assemblies. This corrosion has led to surface cracking and spalling of the concrete (Figure 1). The salt encrustation from leaks had resulted in diffusion of chlorides into the concrete thereby initiating reinforcement corrosion. Concrete remediation and installation of an impressed current cathodic protection (ICCP) system was required in order to achieve the desired life of 50 years for this 15 year old asset.

Concrete Remediation Works Aurecon developed a methodology to remediate the corroding steel bolts and mitigate further corrosion on mild steel components and reinforcement. This would allow the tunnel to achieve its required life with minimal ongoing maintenance.

This involved the repair of damaged concrete, encapsulation of mild steel bolts and application of cathodic protection (Figure 2, 3).

During a scheduled shutdown period, extensive repair works were undertaken utilising spray grouting.

These works were performed by multiple crews moving along the tunnel under restricted access conditions due to the presence of the conveyor structure and the walkway.

30 Corrosion & Materials

These repairs addressed damage visible at the time.

ICCP System Design Consideration During the design consideration had to be given to: Resolving the lack of continuity between individual reinforced concrete segments Achieving even current distribution along the structure Monitoring of the performance of the ICCP system by measuring polarisation levels along the tunnel The presence of a vast network of buried and immersed metallic structures surrounding the tunnel such as pipelines and wharfs, many of which with their own high current output ICCP systems installed Requirements by tunnel operations such as short shut down periods, limited access and other works in the vicinity e.g. the construction of multiple new berths including piling straddling the tunnel.

Design Options for the Cathodic Protection System Various design options to provide cathodic protection to the tunnel reinforcement were considered. The three main options were: a) Ribbon/discrete anodes in slots/ drilled holes in the concrete. b) A distributed anode system along the full length of the tunnel. c) Installation of remote anode groundbeds at the two ends of the tunnel.

Option c) stood out due to simplicity of the approach, lower risks and comparably low cost and was consequently selected as preferred option. A trial was performed to assess the suitability of this approach.

Based on positive results from the trial this option was selected for a feasibility study and subsequently for detailed design and implementation.

Detailed Design The ICCP system was designed with remote anode groundbeds located onshore at the two ends of the tunnel in order to inject current into the steel reinforcement via the soil/sea water/concrete medium.

(Refer Figure 4 for Schematic). The locations were chosen to minimise the risk of stray current interference effects upon buried or immersed metallic structures in the vicinity of the tunnel. The ICCP power supply and monitoring control units (PSMCU) are integrated into an extensive monitoring system which feeds into the clientâ&#x20AC;&#x2122;s SCADA system.

The PSMCUs are linked with a fibre optic communication cable and have 3G modems which allow remote diagnostics and software upgrades.

A continuity system was installed along the tunnel to interconnect the segments and provide a return path for the CP current.

Platinum coated, copper cored niobium anodes were selected for the groundbeds. These anodes offer a long service life, high current output density and high permissible driving voltage in a chloride environment.

The total output capacity is 450 amps with a 50 year design life. The anodes are located in a calcined coke backfill.

CP System monitoring is performed using embedded silver/silver chloride reference electrodes. A total of 44 monitoring stations were installed along the tunnel. Each monitoring station consists of 5 reference electrodes, distributed at various locations around the circumference reflecting variations in circumferential exposure conditions. Monitoring can be undertaken at the PSMCU units at either end of the tunnel or remotely via the site SCADA system.

Figure 1: Saltwater leak through panel seal and heavily corroded steel plate and bolt

Figure 2: Spray-grouting of bolt pockets

Construction The greatest challenge during construction was installation of the anode groundbeds with coke backfill within tidal areas (Figure 5 and 6).

Challenges involved: 1. Groundbed trenches would fill with water for a significant portion of the Figure 3: Tunnel after completed repairs

day, with high tides fully immersing the locations.

2. Trench walls dug in sandy water saturated soil would easily collapse.

3. Any damage to mangroves present at the locations would have to be environmentally approved, hence, had to be minimised.

C

NR

NR

NR

NR

NR

NR

Fibre Optic Link Island PSMCU

JB

Negative Return Box Anode Groundbed

Continuity Bond Cable

Mainland PSMCU

Negative Continuity Box Anode Groundbed

JB

Figure 4: CP System overview www.corrosion.com.au

Vol 36 No 6 December 2011

31

Project Profile

Figure 5: Groundbed Figure 7: Example of depolarisation trends as produced by the SCADA System

Commissioning and Operation Commissioning was performed in accordance with AS 2832.5 to achieve internationally accepted criteria for protection.

Figure 6: Groundbed installation

4. Coke backfill could be washed out of trench during tide movement.

To overcome these challenges canisterised anodes were manufactured consisting of 5.0m long steel troughs. The entire canister was wrapped in geotextile fabric to prevent washing out of the coke. One 2.0m long anode was placed centrally in the coke. These canisters were lifted into the trench and joined with the previous canister to obtain a continuous groundbed.

This methodology ensured: Fast progress of the installation No coke was washed out during construction or can be washed out during the operation The risk for trench wall collapse was minimised Trenching/installation could continue during the subsequent low tide without significant preparation.

32 Corrosion & Materials

After 12 weeks depolarisation testing found that >98% of the reference electrodes had achieved satisfactory levels of protection. Additional polarisation would continue with time with a total output from the PSMCUs of 260 amps. An example of the depolarisation trends is shown in Figure 7.

Interference testing was conducted as part of the commissioning process.

Some adverse effects were noted on nearby buried pipes and wharves.

To mitigate these effects bonding systems were designed. Cables were run from the interference mitigation terminals provided at each PSMCU to each affected asset where the adverse effect was most prominent and connected via blocking diodes.

This project demonstrated that a long reinforced concrete segmented tunnel structure can be protected by cathodic protection utilising remote external anode groundbeds.

Construction and site issues provided challenges to the development and implementation of this ICCP system due to dense heavy infrastructure and ongoing infrastructure expansion activities. However

these were mitigated by flexibility, communication and innovative design during all stages of the work. Stray current issues were encountered but have been readily mitigated as early consideration was given to this during the design. A project of this nature requires close coordination amongst the designers, the owner, manufacturers, and installers as well as stakeholders to achieve the desired outcome.

(Editors Note: For more information about this project refer to 18ICC Proceedings, Paper No. 357.)

U. Kreher, I. Solomon, A. Vinnell Aurecon Australia Pty Ltd

IDEC Protective Coatings In what year was your company established?

IDEC Protective Coatings was established in 2007.

How many employees did you employ when you first started the business?

Approximately 35.

How many do you currently employ?

Approximately 35.

Do you operate from a number of locations in your home state or in other states of Australia?

We have a large blasting and painting facility in Hemmant, on the south side of Brisbane. We do work for projects that are located all over Australia and overseas, however our operation is focused here at our facility. We do offer limited on-site services to our existing clients.

What is your core business? (e.g. blasting and painting, rubber lining, waterjetting, laminating, insulation, flooring etc.)

Our core business is Blasting and Painting. We have 2 metal shot rooms and a garnet room.

What markets do you cover with your products or services? eg: oil & gas, marine, chemical process, general fabrication, tank lining, offshore etc.

We specialise in: Oil and Gas Pipework (including internal blasting and painting) Fuel Tank Plates Tanks Structural Steel.

Is the business yard based, site based or both?

We are yard based and offer limited site based services, usually to existing clients on projects that we have done the yard based work for.

www.corrosion.com.au

What is your monthly capacity or tonnage that you can blast and prime?

We do a wide variety of different jobs so it is difficult to measure the tonnage. We have quite a large capacity and currently have 2 of our 3 rooms running full time, including a small crew on night shift. We are not running at full capacity and hope to build this up over the next 12 months.

Do you offer any specialty services outside your core business? (eg. primary yard based but will do site touch up etc.)

We are focused on our core business.

What is the most satisfying project that you have completed in the past two years and why?

We recently completed a difficult project for ACLAD, which included odd shaped and twisted fins for the external of the new ABC premises in Southbank. This project was pleasing because we established specialised hangars in order to paint the fins without having to turn them. The building looks amazing and it is pleasing to drive past and know that we contributed to the completion of the project.

What positive advice can you pass on to the Coatings Group from that satisfying project or job?

Where possible, research the job before it arrives and establish a materials handling solution which will help save time and increase quality assurance outcomes.

Do you have an internal training scheme or do you outsource training for your employees?

We do both internal and external training for our staff.

We are lucky enough to have some industry veterans in our company who are willing to train some of the younger employees on the tricks of the trade.

Contact Details: Jason Dukes General Manager (07) 3396 7155 jasond@idec.com.au www.idec.com.au

Vol 36 No 6 December 2011

33

Technical Note Copper Based Antifouling Coatings on Aluminium Hulls (Cuprous Oxide and Cuprous Thiocyanate) were used in the experimental work.

Traditionally copper based antifouling coatings (mostly Cuprous Oxide) have not been used on aluminium hulls due the concern that corrosion of the hull will occur due to the electrochemical potential differences between the cuprous oxide and the aluminium hull. Recent laboratory investigation and a review of field experience has shown that there are other factors that are important to be properly controlled to avoid corrosion.

Although they provide excellent long term antifouling efficacy tributyl tin materials are no longer acceptable under International Maritime Organisation regulations and the materials currently used on Steel hulls were investigated to assess suitability for aluminium hulls.

The use of Cuprous Oxide (Cu2O) based antifouling coatings provide significantly longer periods of fouling control than the low copper option of Cuprous Thiocyanate (CuSCN) and so there were compelling commercial and practical reasons for evaluating Cuprous Oxide based products on aluminium hulls.

Introduction The use of copper based antifouling coating (typically based on red copper oxide) on steel-hulled vessels has been widely used and the traditional practice for aluminium hulls was to use either non-copper based active ingredients (eg tributyl tin compounds) or low copper content materials such as Cuprous Thiocyanate.

Experimental Samples of commonly used materials for vessel construction – aluminium plate (AA5083 - 4mm x 40 mm x 100 mm) and carbon steel (St 37 - 3mm x 40 mm x 100 mm) – were obtained and a series of tests were carried out in quadruplicate.

The avoidance of Copper materials on aluminium hulls is driven by the action of the dissimilar metals and the greater potential for aluminium to corrode when coupled with copper.

The use of copper compounds rather than metallic copper is a difference that needed to be investigated.

Metallic copper as well as the two most prominent copper compounds

A test solution of 3% Sodium Chloride was inoculated with copper compounds as per Table 1.

Table 1

Test No

1

Cu content (ppm)

Amount of Cu containing compound (mg/l)

Metal Sample Type

Cu 1

Cu2O

CuSCN

Aluminium

Steel

1

0

0

0

0

X

2

10

10

0

0

X

3

10

0

11.3

0

X

4

10

0

0

19.1

X

5

0

0

0

0

X

6

10

10

0

0

X

7

10

0

11.3

0

X

8

10

0

0

19.1

X

Metallic copper added as finely divided powder.

34 Corrosion & Materials

The differing levels of the various compounds were calculated to provide the same final Copper content in the test solution. All of these levels are significantly in excess of the solubility of the materials so a saturated solution will occur.

The metal samples were fully immersed in the different solutions and all samples were tested as duplicates with different containers used for each Test and magnetic stirrers fitted to provide uniform exposure during the test. The duplicate specimens were supported by plastic clips to maintain separation and vertical orientation in the liquid.

Prior to testing the edges of each sample was abraded with SiC paper to minimise any “edge effects”, rinsed in fresh water, degreased in acetone, dried and weighed. The test panels were not blast cleaned or specially prepared prior to test.

The test procedure was carried out at 20 – 23 °C and the duration of the test was 28 days.

After the test period three of the quadruplicate samples from each solution were rinsed and dried and stripped of corrosion product according to ASTM G1.

Results Average corrosion rates were determined from the calculated weight loss. As would be expected the corrosion rate for aluminum was much lower than for steel and the results are shown in Table 2.

The results only provide average corrosion rates and do not indicate the susceptibility to pitting which can be much more serious. This is difficult to rank quantitatively and descriptions of the observations are shown in Table 3.

Table 2

Test No

Cu content (ppm)

1

0

2

Amount of Cu containing compound (mg/l) Cu

Metal Sample Type Steel

Average Corrosion Rate (µm/year)

Cu2O

CuSCN

Aluminium

0

0

0

X

1.29

10

10

0

0

X

35.70

3

10

0

11.3

0

X

43.91

4

10

0

0

19.1

X

29.50

5

0

0

0

0

X

240.7

6

10

10

0

0

X

191.3

7

10

0

11.3

0

X

272.7

8

10

0

0

19.1

X

302.3

1

Table 3

1

Test No

Substrate

Largest pit depth (µm)

Comments

1

Aluminium

(90)1

2

Aluminium

65

Numerous pits all of similar depth – greater pit density than Test 4 but less than Test 3.

3

Aluminium

60

Moderate variation in pit density from different sample faces and greatest number of pits in general on aluminium samples.

4

Aluminium

(100)1

5

Steel

-

6

Steel

80

Mostly shallow pits (< 50 µm) and also with variation between faces of the samples. Less pits in total than Test 7 and Test 8.

7

Steel

110

Most pitting is below 50 µm and with some that appear to be aggregated pits – also variation between the sample faces. Greatest number of pits for steel Tests.

8

Steel

110

Similar to Test 7 but with less pits – although still more pitting than Test 6.

3 pits in total identified – all deeper than 50 µ. Located close to damage areas/edges.

Mostly shallow pits with very few deeper pits. Located close to damage areas/edges.

Only very shallow – micro-pits.

Pits located in damage areas or near edges.

Discussion Even though there is a larger potential for galvanic corrosion of aluminium than for steel in the presence of copper the performance of the Test samples shows that there is not a significant difference in the average corrosion rate for all three copper compounds assessed on the different substrates. The incidence of pitting is also not significantly different between the three compounds on each of the substrates.

www.corrosion.com.au

Even though the differences are not significant there are some unusual results in the values obtained.

CuSCN shows the highest average corrosion rate on steel and the Cu (metal) Test is the lowest result for all steel samples (including the “blank” sample).

The suitability of Cu2O based antifouling coatings for aluminium hulls is therefore dependent on other factors which include sufficient

thickness of a non conductive protective coating applied to the hull and a suitably installed cathodic protection system. There is an increasing use of Cu2O based antifouling coatings on aluminium vessels on a global scale and the over cautious approach of the past is not valid.

By E.Riding Jotun Australia

Vol 36 No 6 December 2011

35

Technical Note Effect of Surface Roughness on the Corrosion of 316-type Stainless Steel Introduction Corrosion was detected on a number of wires of 3mm diameter made from stainless steel as shown in Fig.1. It was found that the corrosion had occurred even before the wires were exposed to service.

The service environment was near neutral pH water which was slow flowing. A chemical analysis of the wires had shown that the wires met the requirements of ASTM A314 specifications for 316-type stainless steels. These results indicated that the Cr content of the wires was close to the lower limiting values for specification as 316-type stainless steel. Significantly, C content was 0.04% and S content about 0.01%.

It is well known that 316-type stainless steels have 2-3% Mo added specifically to resist pitting corrosion in chloride environments. Stainless steels are also generally passivated before they are used in service.

Corrosion in this instance was not easily explained.

A number of tests were undertaken to investigate the causes of corrosion.

Experimental Observations A small number of corroded and non-corroded samples were randomly selected from the material for testing. The tests included a test (ASTM 967) to locate any carbon steel present on any of the wires. Carbon steel has been known to cause corrosion if stainless steel material

is not sufficiently passivated. In order to determine if the wires were contaminated by free-iron particles, a solution of potassium ferricyanide and nitric acid solution was prepared as specified in ASTM A967 and the samples are swabbed with this solution.

Another line of investigation was to identify if the samples had received appropriate heat treatment. Stainless steels when improperly heat treated can produce chromium carbides and sigma phases and these are detrimental to corrosion. For this, optical and Scanning Electron Microscopy (SEM) examination of the samples was performed.

Microscopic examination of the wires was expected to give a valuable insight into the heat and mechanical treatments used during and subsequent to manufacture.

Samples were also subjected to immersion in 10%FeCl3 solution for 72 hours in order to identify issues of corrosion in the present samples.

The ASTM G48 test was chosen because it is quick and sensitive to changes in pitting resistance of stainless steels. Weight loss in this test gives a comparison to rate materials with different corrosion resistances. The samples were also tested in horizontal and vertical positions to investigate possible effects of attitude.

50 Âľm

Fig.1 Corrosion had occurred on some wires even before being put to service.

36 Corrosion & Materials

Fig.2 Microstructures typical of both corroded and uncorroded wires with twinning from cold working.

Results and Discussion Iron contamination The tests for iron contamination did not show any presence of iron.

Normally swabbing with a solution containing potassium ferricyanide and nitric acid gives a blue colour in the presence of free iron. No blue colouration from corroded areas was observed.

Microstructures The optical microscopy picture of both corroded and uncorroded samples showed that microstructures, as in Fig 2, consisted of twinning and step structure typical of annealed stainless steels. The dark spots are etch pits. There was nothing to suggest that there were carbide or sigma phases. The SEM Energy Dispersive Spectroscopy (EDS) analysis showed that there was chlorine present in the corrosion product.

Surface inspection Visual examination of the samples showed that those with previous corrosion stains exhibited mechanical damage on its surface as shown in Fig.3. Folds and spiralling features were visible on the surface. The samples without previous corrosion also showed some mechanical damage but, significantly, did not exhibit any spiral defects as shown in Fig.4.

Corrosion tests The results of the test after immersion in 10%FeCl3 indicated that the sample with previous corrosion suffered excessive weight loss (30%).

The samples that had no previous corrosion stains showed much lower weight loss (1-3%). In comparison, a typical 316-type stainless steel had showed a corrosion rate of 1.5% in 6%FeCl3[1]. In general, all the samples had exhibited greater weight loss than that expected from existing literature.

Spiral mech damage

Uniform yellow Stains

Corrsem 1

Fig.3 Spiralling defect seen on samples that had previously exhibited corrosion stains.

Inset shows uniform yellow stains.

Pattern of mech damage

Localised yellow Stains

wires had spiral damage, probably resulting from wire twisting as it passed through the reduction die.

This could have also produced smearing and folding of the wires[3].

Conclusions Corrosion on some wires appears to be the result of surface defects. Wires with corrosion stains showed spiral markings and surface folds, and exhibited excessive pitting.

Wires without visible corrosion stains also produced pitting, but their loss in weight was much less.

Nocorrsem 1

Fig. 4 Some mechanical damage on the wire that did not have previous corrosion.

Inset shows localised yellow stains.

Both corroded and uncorroded samples examined under a microscope exhibited pitting but the degree of pitting differed. The sample with the greatest weight loss exhibited more extensive pitting and spiral marks on its surface also contributed to pitting as shown in Fig 5. In contrast, the sample that did not have corrosion stains had fewer pits and the minor scuffing on its surface did not increase pitting.

The upper sample, Fig.5a, had pits along the spiral defect as well as pits in other areas. Pitting is much less in the lower sample, Fig.5b, (which was taken from a wire without corrosion stains). Both samples show localised pitting, although much of the lower sample appears to be generally in good condition.

Corrosion on some wires appears to be the result of surface defects, particularly the spiral damage which produced excessive corrosion rates. Wires with corrosion stains had mechanical damage that went around and along the wire in a spiral pattern. Defects produced by the process of wire drawing have been subject to intense study[2], but specifications for surface quality are still in development. Surface quality of wire affects fatigue and corrosion in bio-medical applications. Surface folds are thought to be the result of mechanical damage during the process of wire drawing, probably due to incomplete or incorrect cleaning of dies[3]. Existing literature indicates that surface conditions have a significant effect on resistance to corrosion[4]. Significantly, corroded

a.

b.

www.corrosion.com.au

Fig.5 Pitting after immersion in 10%FeCl3 solution.(a) had previous corrosion stains showing pits along spiral marks. (b) no previous corrosion stains.

Defects in the wire are thought to have been produced during manufacture, probably due to defective dies.. Spiral defects were probably as a result of twisting of the wire as it passed through the reduction die.

References [1] Mars G. Fontana, Corrosion Engineering, 3rd edition, Tata McCraw Hill, 2005.

[2] S hinohara T and Yoshida K, Deformation analysis of surface flaws in stainless steel wire drawing, Journal of Materials Processing Technology 162â&#x20AC;&#x201C;163 (2005) 579â&#x20AC;&#x201C;584.

[3] R entler RM and Greene ND, Corrosion of Surface Defects in Fine Wires, Journal of Biomedicine Material Research, 9 55 (1975) 597-610.

[4] A SM Metals Handbook, On Dialog DVD, Corrosion, Volume 13, Materials Park, Ohio, 1998.

Krishnan Kannoorpatti1, David M Lilley1 and Grahame Webb2 North Australian Centre for Oil and Gas, School of Engineering and IT, 2Research Institute for the Environment and Livelihoods, Charles Darwin University, Darwin, NT Australia, 2Wildlife Management International, Berrimah, NT Australia

1

Vol 36 No 6 December 2011

37

Research Paper Shedding light on Corrosion A. J. Davenport University of Birmingham, UK Summary Highly intense synchrotron X-rays are ideal probes for studying corrosion processes since they can penetrate water and metal surfaces, and offer a wide range of techniques for determining the time-dependent morphology and chemistry of sites with micron resolution.

X-ray microtomography and radiography can show the evolution of corrosion damage in 3D or 2D, X-ray absorption spectroscopy gives chemical information inside growing corrosion pits, and X-ray diffraction can be used to identify the salt films that form inside artificial pits. These techniques have been applied to study localised corrosion of stainless steel and nickel, atmospheric corrosion of aerospace alloys, and localised corrosion of Ti for biomedical applications.

1. Introduction Localised corrosion sites are particularly difficult to study as they develop in wet environments and many of the most effective characterisation methods must be carried out in a vacuum. However, there is a variety of photonbased techniques that can allow characterisation of the chemistry and morphology of localised corrosion processes.

Synchrotron X-ray based techniques offer a particular advantage, since the highly intense X-rays are readily able to penetrate water and, in some cases, metal. Furthermore, the highly tuneable nature of the beams means that a range of techniques are available including imaging, diffraction/ scattering and spectroscopy.

Synchrotron X-ray methods have been used to study corrosion and passivation of metals since the 1980s. Much of the earlier work involved characterisation of passive oxide films on alloys such as iron, stainless steel and copper with X-ray absorption spectroscopy e.g. [1-6] as well as the effect of corrosion inhibitors e.g. [7, 8]. In situ single crystal diffraction has also been used to study the passive film on iron [9] and nickel [10], and X-ray fluorescence has been applied to study the effect of composition thresholds on dealloying processes [11] as well as the composition of the solution in localised corrosion sites [12, 13]. More recent work has involved the application of many of these techniques to the corrosion of archaeological artefacts, e.g. [14, 15], oil and gas corrosion [16, 17], corrosion of Mg in the body [18], stress corrosion cracking [19] and microgalvanic processes [20]. However, relatively little work has focused on the morphology and chemistry of localised corrosion sites.

In this paper, the use of a range of methods for exploring the characteristics of localised corrosion in stainless steel, nickel, aluminium and titanium systems is explored, with

38 Corrosion & Materials

}

This paper was originally published in the 18th International Corrosion Conference Proceedings.

applications ranging from nuclear waste storage and airframe alloys though alloys with biomedical applications.

2. X-Ray Imaging of Localised Corrosion of Stainless Steel X-ray microtomography is a method for studying the evolution of corrosion in 3D. It involves using a sample with rod-like geometry and taking a series of many 2D images as the sample is rotated around the axis of the rod. The series of 2D images can then be mathematically reconstructed to give a 3D structure. This approach has been used to study corrosion of magnesium [18, 21], aluminium [22-25], and stainless steel [19, 25, 26]. Figure 1 shows a tomographic image of a stainless steel pin 0.5 mm in diameter onto which a microcapillary cell has been lowered (using a device developed by Suter [23, 26]). (The measurement was performed at the TOMCAT beamline of the Swiss Light Source using the experimental setup described in Reference [26].) The pin is easily visible owing to the difference in density between the stainless steel and the surrounding air (absorption contrast), whereas the lower density glass capillary and silicone coating can be resolved owing to phase contrast enhancement if the detector is placed at some distance (a few cm) from the sample. Using this device, the growth of a corrosion pit can be observed.

Figure 2 shows a vertical section through the reconstructed tomogram of the metal pin containing a corrosion pit that is growing under galvanostatic control. The upper image shows the pit following growth for 1 minute. It shows the characteristic â&#x20AC;&#x153;lacy coverâ&#x20AC;? that forms on pits in stainless steel grown in salt solutions [27]. The lower figure shows the same section of the pit following growth for 6 minutes.

It is evident that the morphology of the central part of the pit cover has not changed, but that further pit growth has taken place through the growth of side lobes, confirming the mechanism proposed by Ernst et al. [27].

silicone coating glass capillary solution inside in contact with metal metal pin

Figure 1 X-ray microtomography image of a microcapillary cell on the top of a 0.5 mm diameter metal pin.

1 min 6 min

Figure 2 Vertical section of a 304 stainless steel pin through a pit grown galvanostatically in 1 M NaCl at 500 ÎźA for (a) 1 min, and (b) 6 min (after exposure at OCP for 5 min during the prior image collection).

solution Pit

25 µm Figure 3 X-ray radiography image of a pit at the edge of a 20 μm foil of 304 stainless steel in 0.1 M NaCl at 650 mV(Ag/AgCl).

Votage = 650 mV

600 400

20

200

10 0

Current = 22 µA

-10

0

Voltage (mV)

Current (µA)

30

Figure 5 shows a simple cell that can be used to monitor atmospheric corrosion in situ. A drop of salt water is placed on the tip of the rod, and the sample is covered with a plastic tube containing filter paper saturated with a salt solution that gives a desired relative humidity (RH). The salt droplet on the pin equilibrates with the humidity of the environment, reaching the same water activity as the solution in the filter paper. The effect of salt loading density (average concentration of chloride ions per unit area) on the pin and RH can therefore be controlled independently, so that the effect of droplet height can be investigated.

Preliminary results (not shown) for atmospheric corrosion of AA2024, an Al-Cu-Mg aerospace alloy, suggest that for a fixed RH, a higher salt loading density will give a higher droplet height, which will lead to greater localised corrosion by decreasing the resistance between anode and cathode.

This is consistent with observations of atmospheric corrosion of stainless steel under deliquesced salt patches deposited with an inkjet printer [29]. filter paper saturated with salt solution to control relative humidity

-200 -400

0

100

salt-water droplet: size controlled by salt content and relative humidity

200

300 400 500 600 Time (Seconds) Figure 4 Current and voltage as a function of time for the pit shown in Figure 3 (voltage is shown relative to Ag/AgCl).

The tomography experiments are relatively slow (data collection times are 5-10 minutes), making it difficult to capture the detailed kinetics of pit growth. This can be achieved using fast radiography of 2D pits growing at the edge of metal foils following the approach used by Ernst et al. [27]. Figure 3 shows an X-ray radiography image from a video sequence of a pit growing at the edge of a 304 stainless steel foil. Again the characteristic lacy cover can be observed, and in this case the growth of a side lobe on the right side of the pit can be observed.

Figure 4 shows the current/voltage characteristics as a function of time for the growth of the pit shown in Figure 3. This allows correlation of the electrochemical behaviour of the pit with its growth morphology. The local rate of pit growth at each point along the pit boundary can be measured from the velocity of the interface determined from the pit growth video sequence. This experimental approach is being used to extract pit growth kinetic parameters in order to refine a pit growth model that is being developed by Ghahari et al for prediction of pitting corrosion of nuclear waste canisters [28].

3. Atmospheric Corrosion of Aluminium Alloys Atmospheric corrosion of aluminium alloys is a concern for the integrity of aircraft, and the development of corrosion prediction models requires knowledge of the morphology and kinetics of corrosion. X-ray microtomography is an ideal method for studying atmospheric corrosion [24]. www.corrosion.com.au

1 mm diameter silicone tubing AA2024 AI aerospace alloy 3 mm rod Figure 5 Experimental cell used for measuring atmospheric corrosion of aluminium alloys.

200 µm salt crystals likely to be NaCl

intergranular corrosion fissures appear to develop under NaCl crystals Figure 6 Vertical section of a tomogram of a sample of AA2024 that has been corroded in a mixture of NaCl and MgCl2 solution for 23 hours at 90% RH and then dried out for 2 hours at 30% RH.

Figure 6 shows a vertical section of the tomogram measured following corrosion of AA2024 in a mixed solution of NaCl and MgCl2 initially at high humidity and dried out.

The corrosion morphology is in the form of intergranular Vol 36 No 6 December 2011

39

Shedding light on Corrosion

These measurements were made at the TOMCAT beamline at the Swiss Light Source, which has an robotic samplechanger, so that a set of samples can be repeatedly measured at intervals (each tomogram takes a little less than 10 minutes to collect) to determine the evolution of corrosion damage with time as well as the response to wetting and drying cycles. A key question for corrosion prediction models is whether, after a drying and re-wetting cycle, existing corrosion sites re-initiate or new ones initiate. Preliminary results suggest that with thorough drying of exposed surfaces at low RH (~30%), new sites initiate and “old” sites do not corrode further. However, it may be difficult to dry out deep fissures or crevices, so further work is required to explore this.

4. Salt Films in Artificial Pits For a corrosion pit formed in chloride-containing environments to be stable, it is necessary to maintain an aggressive highly concentrated acidic metal chloride solution adjacent to the dissolving metal. If metal ions are able to diffuse away, then the solution will become more dilute and the pit can repassivate. Thus stable pits tend to have locally high metal chloride contents, which may reach supersaturation leading to precipitation of a salt film. The presence of the salt film can change the pit growth kinetics and alter the pit shape. However, relatively little is known about the nature of these salt films since they can only be studied in situ on dissolving interfaces.

Studies of the formation and dissolution of salt films are generally carried out in 1D artificial pits formed by embedding either a wire or foil in epoxy resin and dissolving the metal back to form the pit cavity. While there have been quite extensive studies of the electrochemistry of salt film formation (e.g. [30-33]), characterisation of their chemical nature has been confined to Raman spectroscopy (e.g. [34]) and synchrotron X-ray fluorescence mapping [12, 13]. We have recently demonstrated the feasibility of studying the crystallography of salt films using microfocus synchrotron X-ray diffraction using an artificial pit constructed from a metal foil [35]. Using this approach, we are now able to resolve the chemistry of the film through its thickness.

The nature of the salt films formed in a Ni artificial pit is illustrated in Figure 7, a radiograph taken from a video sequence showing the formation of a salt film following a potential step measured at the Swiss Light Source (TOMCAT beamline). In order to measure the chemistry of such a salt

40 Corrosion & Materials

film through its thickness, diffraction measurements have been made at Beamline I18 at the Diamond Light Source with a beam ~3 μm high and ~5 μm wide. Measurements were made initially with the beam passing through the solution above the film and the sample was raised in small increments until the only diffraction came from the metal.

Figure 8 shows diffraction patterns from the solution, a location in the salt film close to the solution, a location in the salt film close to the metal surface, and in the metal.

The main salt film has a powder pattern consistent with NiCl2.6H2O, the phase identified with Raman by Sridhar and Dunn [34]. However, variation in the diffraction pattern close to the metal (not shown), suggests that the salt film may not be homogeneous through its thickness.

10 µm

solution

salt film

Ni foil Figure 7 Radiograph showing formation of a salt film following a potentiostatic step on a rapidly-dissolving Ni foil in an artificial corrosion pit grown in 1 M HCl. The “false” colours represent relative absorption of X-rays (blue for dense metal, green/yellow for the salt film and orange for the lower density solution).

1.6

normalised absorption

fissures parallel to the rolling direction of the alloy; these can readily be seen via absorption contrast. In addition, salt deposits are seen on the surface together with a film of liquid, which are visible through a mixture of absorption contrast and phase contrast. The salt crystals are likely to be NaCl, since this undergoes deliquescence at a considerably higher RH than MgCl2. It appears that major localised corrosion sites are often located under salt crystals, which may act as crevice formers.

1.2

0.8 CP-Ti foil pit TiCl4 / HCI anatase rutile

0.4

0

4970

4980

4990

5000

5010

5020

Figure 8 Normalised Ti K edge XANES inside a titanium artificial pit grown at 7 V(Ag/AgCl). The spectra are compared with standard spectra for anatase, rutile, 9 mM TiCl4 in 0.55 M HCl, and Ti foil.

5. Chemistry of Molybdenum in Pits In Stainless Steel X-ray absorption spectroscopy is another synchrotron technique that can yield valuable information on the chemistry of localised corrosion sites. Kimura et al. [36] used X-ray absorption spectroscopy to address the longstanding question as to the role of Mo in improving the corrosion resistance of stainless steels. They carried out measurements inside artificial pits and attributed the spectra that they found to â&#x20AC;&#x153;[MoO4(H2O)2]2- octahedraâ&#x20AC;?, and proposed that these act as corrosion inhibitors via the formation of a molybdate network within the pits. However, more recently, we carried out similar measurements with higher spatial resolution and a larger range of standard compounds [37], finding spectra that are more consistent with Mo3+, the species expected on thermodynamic grounds [38]. As Mo3+ is not likely to act as a corrosion inhibitor, we inferred from this that Mo is more likely to block anodic dissolution through the formation of a monolayer species on the dissolving interface, which has been proposed by a number of previous authors (e.g. [39, 40]).

6. Chemistry of Titanium Inside Localised Corrosion Sites Titanium is commonly used for the manufacture of biomedical prostheses as it is highly corrosion resistant owing to the formation of an inert passive film of TiO2.

However, despite this, there are reports of corrosion failures of Ti in the body, particularly for cemented hip prostheses [41, 42], and Ti species have been observed in tissue around implants [43, 44]. In order to shed light on the species likely to be generated by corrosion of Ti in the body, we have carried out preliminary characterisation of the species present in Ti artificial pits using X-ray absorption near edge structure (XANES).

Artificial pits in Ti will only grow at relatively high potentials [45]: we used 7 V(Ag/AgCl) in this case. The pits contain some solid precipitated material. Figure 8 shows a typical spectrum from a region of the artificial pit containing both solid and liquid components (black line). A comparison with the standard spectra suggests that the dominant solution species is TiCl4, which hydrolyses to form a species similar to anatase (TiO2) in the pit solution. Further work is ongoing to relate the species found in artificial pits to those found in human tissue around implants.

7. Conclusions Synchrotron X-ray methods offer a variety of probes for characterising the morphology and chemistry of localised corrosion sites that can provide fundamental mechanistic information for applications such as nuclear waste storage and air frame corrosion.

8. Acknowledgments The author would like to acknowledge the contributions of her collaborators: Prof Trevor Rayment (Diamond Light Source), Majid Ghahari, Mehdi Monir, Josh Hammons, Jean-Philippe Tinnes, Na Mi, Andrew du Plessis, Dr Owen Addison, Sonam Kalra, (U. Birmingham), Dr Richard www.corrosion.com.au

Martin (U. Aston), Prof Bob Newport (U. Kent), Prof Fred Mosselmans, Dr Paul Quinn, Prof Andy Dent (Diamond Light Source), Prof Marco Stampanoni, Dr Federica Marone, Dr Peter Modregger (Swiss Light Source), Dr Steve Knight and Dr Tony Trueman (DSTO Australia), Dr Cristiano Padovani (NDA) Dr Thomas Suter (EMPA). This work was supported in part by EPSRC, NDA, and DSTO/DMTC. 9. References [1] Long GG, Kruger J, Black DR, Kuriyama M, Structure of passive films on iron using a new surface-EXAFS technique, J Electroanal Chem 150(1-2) (1983) 603-610.

[2] Davenport AJ, Sansone M, Bardwell JA, Aldykiewicz AJ, Taube M, Vitus CM, In situ multielement XANES study of formation and reduction of the oxide film on stainless steel, J Electrochem Soc 141(1) (1994) L6-L8.

[3] Bardwell JA, Sproule GI, Macdougall B, Graham MJ, Davenport AJ, Isaacs HS, In situ XANES detection of Cr(VI) in the passive film on Fe-26Cr, J Electrochem Soc 139(2) (1992) 371-373.

[4] Kruger J, Long GG, Studies of the nature of the passive film on iron using EXAFS, J Electrochem Soc 133(8) (1986) C302-C302.

[5] Davenport AJ, Sansone M, High resolution in situ XANES investigation of the nature of the passive film on iron in a pH 8.4 borate buffer, J Electrochem Soc 142(3) (1995) 725-730.

[6] Druska P, Strehblow HH, In situ examination of electrochemically formed Cu2O layers by EXAFS in transmission, J Electroanal Chem 335(1-2) (1992) 55-65.

[7] Kendig MW, Davenport AJ, Isaacs HS, The mechanism of corrosion inhibition by chromate conversion coatings from X-ray absorption near edge spectroscopy (XANES), Corros Sci 34(1) (1993) 41-49.

[8] Davenport AJ, Isaacs HS, Kendig MW, XANES investigation of the role of cerium compounds as corrosion-inhibitors for aluminum, Corros Sci 32(5-6) (1991) 653-663.

[9] Davenport AJ, Oblonsky LJ, Ryan MP, Toney MF, The structure of the passive film that forms on iron in aqueous environments, J Electrochem Soc 147(6) (2000) 2162-2173.

[10] Magnussen OM, Scherer J, Ocko BM, Behm RJ, In situ X-ray scattering study of the passive film on Ni(111) in sulfuric acid solution, J Phys Chem B 104(6) (2000) 1222-1226.

[11] Davenport AJ, Ryan MP, Simmonds MC, Ernst P, Newman RC, Sutton SR, Colligon JS, In situ synchrotron X-ray microprobe studies of passivation thresholds in Fe-Cr alloys, J Electrochem Soc 148(6) (2001) B217-B221.

[12] Isaacs HS, Huang SM, Behavior of dissolved molybdenum during localized corrosion of austenitic stainless steel, J Electrochem Soc 143(12) (1996) L277-L279.

[13] Isaacs HS, Cho JH, Rivers ML, Sutton SR, In-Situ X-Ray Microprobe Study of Salt Layers During AnodicDissolution of Stainless-Steel in Chloride Solution, J Electrochem Soc 142(4) (1995) 1111-1118.

[14] Monnier J, Reguer S, Vantelon D, Dillmann P, Neff D, Guillot I, X-rays absorption study on medieval corrosion layers for the understanding of very long-term indoor atmospheric iron corrosion, Appl Phys A-Mater Sci Process 99(2) (2010) 399-406.

Vol 36 No 6 December 2011

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Shedding light on Corrosion

[15] Adriaens A, Dowsett M, Time resolved spectroelectrochemistry studies for protection of heritage metals, Surf Eng 24(2) (2008) 84-89.

[16] Ingham B, Ko M, Kear G, Kappen P, Laycock N, Kimpton JA, Williams DE, In situ synchrotron X-ray diffraction study of surface scale formation during CO2 corrosion of carbon steel at temperatures up to 90 degrees C, Corros Sci 52(9) (2010) 3052-3061.

[17] De Marco R, Jiang ZT, Pejcic B, Poinen E, An in situ synchrotron radiation grazing incidence X-ray diffraction study of carbon dioxide corrosion, J Electrochem Soc 152(10) (2005) B389-B392.

[18] Witte F, Fischer J, Nellesen J, Vogt C, Vogt J, Donath T, Beckmann F, In vivo corrosion and corrosion protection of magnesium alloy LAE442, Acta Biomater 6(5) (2010) 1792-1799.

[19] Marrow TJ, Babout L, Jivkov AP, Wood P, Engelberg D, Stevens N, Withers PJ, Newman RC, Three dimensional observations and modelling of intergranular stress corrosion cracking in austenitic stainless steel, J Nucl Mater 352(1-3) (2006) 62-74.

[20] Gianoncelli A, Kaulich B, Kiskinova M, Prasciolu M, Urzo BD, Bozzini B, An in situ electrochemical soft X-ray spectromicroscopy investigation of Fe galvanically coupled to Au, Micron 42(4) (2011) 342-347.

[21] Davenport AJ, Padovani C, Connolly BJ, Stevens NPC, Beale TAW, Groso A, Stampanoni M, Synchrotron X-ray microtomography study of the role of Y in corrosion of magnesium alloy WE43, Electrochem Solid-State Lett 10(2) (2007) C5-C8.

[22] Eckermann F, Suter T, Uggowitzer PJ, Afseth A, Davenport AJ, Connolly BJ, Larsen MH, De Carlo F, Schmutz P, In situ monitoring of corrosion processes within the bulk of AlMgSi alloys using X-ray microtomography, Corros Sci 50(12) (2008) 3455-3466.

[23] Eckermann F, Suter T, Uggowitzer PJ, Afseth A, Stampanoni M, Marone F, Schmutz P, In Situ Microtomographically Monitored and Electrochemically Controlled Corrosion Initiation and Propagation in AlMgSi Alloy AA6016, J Electrochem Soc 156(1) (2009) C1-C7.

[24] Knight SP, Salagaras M, Wythe AM, De Carlo F, Davenport AJ, Trueman AR, In situ X-ray tomography of intergranular corrosion of 2024 and 7050 aluminium alloys, Corros Sci 52(12) (2010) 3855-3860.

[25] Connolly BJ, Horner DA, Fox SJ, Davenport AJ, Padovani C, Zhou S, Turnbull A, Preuss M, Stevens NP, Marrow TJ, Buffiere JY, Boller E, Groso A, Stampanoni M, X-ray microtomography studies of localised corrosion and transitions to stress corrosion cracking, Mater Sci Technol 22(9) (2006) 1076-1085.

[26] Ghahari SM, Davenport AJ, Rayment T, Suter T, Tinnes J-P, Padovani C, Hammons JA, Stampanoni M, Marone F, Mokso R, In situ synchrotron X-ray microtomography study of pitting corrosion in stainless steel, Corros Sci 53(9) (2011) 2684-2687.

[27] Ernst P, Laycock NJ, Moayed MH, Newman RC, The mechanism of lacy cover formation in pitting, Corros Sci 39(6) (1997) 1133-1136.

[28] Ghahari SM, Krouse DP, Laycock NJ, Rayment T, Padovani C, Suter T, Mokso R, Marone F, Stampanoni M, Monir M, Davenport AJ, Pitting corrosion of stainless steel: measuring and modelling pit propagation in support of damage prediction for radioactive waste containers, Corros Eng Sci Tech 46(2) (2011) 205-211.

42 Corrosion & Materials

[29] Mi N, Ghahari M, Rayment T, Davenport AJ, Use of inkjet printing to deposit magnesium chloride salt patterns for investigation of atmospheric corrosion of 304 stainless steel, Corros Sci 53(10) (2011) 3114-3121.

[30] Isaacs HS, Behavior of resistive layers in localized corrosion of stainless-steel, J Electrochem Soc 120(11) (1973) 1456-1462.

[31] Laycock NJ, Newman RC, Localised dissolution kinetics, salt films and pitting potentials, Corros Sci 39(10-11) (1997) 1771-1790.

[32] Danielson MJ, Transport properties of salt films on nickel in 0.5N HCl, J Electrochem Soc 135(6) (1988) 1326-1332.

[33] Tang YC, Davenport AJ, Magnetic field effects on the corrosion of artificial pit electrodes and pits in thin films, J Electrochem Soc 154(7) (2007) C362-C370.

[34] Sridhar N, Dunn DS, In situ study of salt film stability in simulated pits of nickel by Raman and electrochemical impedance spectroscopies, J Electrochem Soc 144(12) (1997) 4243-4253.

[35] Rayment T, Davenport AJ, Dent AJ, Tinnes JP, Wiltshire RJK, Martin C, Clark G, Quinn P, Mosselmans JFW, Characterisation of salt films on dissolving metal surfaces in artificial corrosion pits via in situ synchrotron X-ray diffraction, Electrochem Commun 10(6) (2008) 855-858.

[36] Kimura M, Kaneko M, Ohta N, In situ analysis of pitting corrosion in artificial crevice of stainless steel

by X-ray absorption fine structure, ISIJ Int 42(12) (2002) 1399-1403.

[37] Davenport AJ, Dent AJ, Monir M, Hammons JA, Ghahari SM, Quinn PD, Rayment T, XANES study of the chemistry of Molybdenum in artificial corrosion pits in 316L stainless steel, J Electrochem Soc 158(5) (2011) C111-C117.

[38] Wang PM, Wilson LL, Wesolowski DJ, Rosenqvist J, Anderko A, Solution chemistry of Mo(III) and Mo(IV): Thermodynamic foundation for modeling localized corrosion, Corros Sci 52(5) (2010) 1625-1634.

[39] Newman RC, The dissolution and passivation kinetics of stainless alloys containing molybdenum .1. Coulometric studies of Fe-Cr and Fe-Cr-Mo alloys, Corros Sci 25(5) (1985) 331-339.

[40] Hashimoto K, Asami K, Kawashima A, Habazaki H, Akiyama E, The role of corrosion-resistant alloying elements in passivity, Corros Sci 49(1) (2007) 42-52.

[41] Hallam P, Haddad F, Cobb J, Pain in the well-fixed, aseptic titanium hip replacement - The role of corrosion, J Bone Joint Surg-Br Vol 86B(1) (2004) 27-30.

[42] Thomas SR, Shukla D, Latham PD, Corrosion of cemented titanium femoral stems, J Bone Joint SurgBr Vol 86B(7) (2004) 974-978.

[43] Flatebo RS, Johannessen AC, Gronningsaeter AG, Boe OE, Gjerdet NR, Grung B, Leknes KN, Host response to titanium dental implant placement evaluated in a human oral model, Journal of Periodontology 77(7) (2006) 1201-1210.

[44] Uo M, Asakura K, Yokoyama A, Ishikawa M, Tamura K, Totsuka Y, Akasaka T, Watari F, X-ray absorption fine structure (XAFS) analysis of titanium-implanted soft tissue, Dental Materials Journal 26(2) (2007) 268-273.

[45] Beck TR, Pitting of titanium .2. one-dimensional pit experiments, J Electrochem Soc 120(10) (1973) 1317-1324.

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}

Research Paper

This paper was originally published in the 18th International Corrosion Conference Proceedings.

0.10

Underprotection of Mild Steel in Seawater, the Calcareous Film

Sample 1 Sample 2 Sample 3

0.08

The Corrosion and Protection Centre, University of Manchester, UK Summary In the situation of underprotection of mild steel in sea water, we are in the situation between the corrosion potential and the protection potential. We will describe an experimental investigation to look at this situation.

Constant current and constant potential methods have been employed together with weight loss, impedance analysis and SEM/EDX, to look at calcareous film growth.

Models explaining the behaviour in a variety of situations will be presented.

1. Introduction This paper is mainly drawn from the PhD thesis of Yang.

From this work one paper has been published [1], the second has been accepted for publication [2] and the third has been submitted [3]. The situation we are studying is where steel is cathodically protected in sea water and we are varying the applied current density from typical protection current densities down to zero, namely the region of underprotection. It is well known that during cathodic protection of steel in sea water, a calcareous film is formed. Indeed, this film was first observed by Davy [4]. The major previous study on underprotection was the early and seminal work by Humble [5]. His weight loss data was after one year exposure at Kure Beach NC and are replotted in Figure 2. As well as carrying out weight loss experiments similar to Humble, Figure 2, we also decided to attempt to model the electrochemical processes of film growth, morphology and composition using electrochemical impedance and SEM/EDX.

Corrosion Rate (mm/y)

D. Scantlebury, YF Yang, E. Koroleva

0.06

0.04

0.02

0.00 -20

0

20

40

60

80

100

120

140

160

180

200

220

Current Density (mA/m2)

Figure 2. Weight loss versus applied current density from [1].

Our open circuit weight loss of 0.09 mm/y agrees surprisingly well with the data from Humble [5] at Kure Beach who measured 105 g/ft2 (0.072 mm/y) after 1y exposure and that of Hudson [6] who secured steel panels to the floating Gosport Ferry pier in Portsmouth Harbour and measured an oft quoted average of 0.13 mm/y after 442 days exposure.

It has always been assumed that this so called calcareous film consisted of calcium carbonate and magnesium hydroxide and that the calcium formed first and the magnesium formed last. This stems from the Humbleâ&#x20AC;&#x2122;s work [8] where he quoted the analysis of the calcareous film as a function of applied current density and showed how the ratio of calcium to magnesium changed. We will dispute this evidence later and we attempt to explain why.

2. Experimental Observations In our study, [1] we first immersed polished steel panels at various current densities and Plate 1-4 shows how the panels look after 7d immersion. They are upside down.

0.07

Weight Loss (mm/y)

0.06 0.05 0.04 0.03 0.02 0

20

40 60 Current Density (mA/m2)

80

Figure 1. Weight loss versus applied current density (replotted from Humble [5]).

44 Corrosion & Materials

100

Plate 1. Open circuit for 1 week.

Plate 2. Applied current density 50mA/m2 for 1 week.

Plate 3. Applied current density 100mA/m2 for 1 week.

(a) Secondary image taken at 500x.

(b) EDX element map of distribution of Mg.

(c) EDX element map of distribution of O.

(d) EDX element map of distribution of Fe.

Plate 4. Applied current 150mA/m2 for 1 week.

A second parallel series of specimens were exposed under identical conditions where their potentials were measured every six hours up to seven days. These specimens were subjected to impedance analysis daily at the potentials previously measured using an ACM Gill Impedance Analyser and the data was analysed using Zview. The equivalent circuit chosen was not arbitrary but arose from the data and will be discussed later. A third series, again was exposed under identical conditions of seven days and was subject to surface analysis using SEM with EDX. 3. Discussion Plates 5-9 are the corresponding SEM micrographs and EDX maps of Mg, Ca, Fe and O each recorded from the same area and at the same magnification. Plate 5 is at open circuit and shows mainly rust nodules on the surface and magnesium deposits overlaying on the surface but calcium is not detected being below the limits (less than 0.5%). Plate 6 cathodically polarised at 50 mA/ m2 shows a similar morphology but with an increase in the magnesium level (Table 1) and the first sign of a calcium containing precipitate. Plate 8 at applied current density 150 mA/ m2 showing an obvious and large calcium containing precipitate.

The equivalent circuit model from which we generate the interpretation of our impedance data has to take into account this SEM data. Our model was based partly on the modes proposed by Deslouis [8], [9] and Chung [10], and is given in Figure 3.

Plate 5. Secondary Electron SEM image and corresponding Single EDX element distribution map for Mg, O and Fe of deposit obtained at open circuit for one week: a. SE image; b - d. Single EDX maps for Mg, O and Fe respectively.

(a) Secondary image taken at 500x.

(b). Single EDX element map of distribution of Mg.

(c). Single EDX element map of distribution of Ca.

(d). Single EDX element map of distribution of Fe. Plate 6. Secondary Electron SEM image and corresponding Single EDX element distribution maps of deposit obtained using an applied current density of 50 mA/m2 for 7 days: a. SE

(e). Single EDX element map of distribution of O.

www.corrosion.com.au

image, b – e. Single EDX maps for Mg, Ca, Fe and O respectively.

Vol 36 No 6 December 2011

45

Underprotection of Mild Steel in Seawater, the Calcareous Film

(a) Secondary image taken at 500x

(b). Single EDX element map of distribution of Mg

(a). Secondary image taken at 500x.

(b). Single EDX element map of distribution of Mg.

(c). Single EDX element map of distribution of Ca.

(d). Single EDX element map of distribution of Fe.

(c). Single EDX element map of distribution of Ca.

(d). Single EDX element map of distribution of Fe

Plate 7. Secondary Electron SEM image and corresponding EDX element distribution maps of deposit obtained using an applied current density of 100 mA/m2 for 7 days: a. SE image; b â&#x20AC;&#x201C; e.

Single EDX maps for Mg, Ca, Fe and O respectively.

Plate 8. Secondary Electron SEM image and corresponding EDX element distribution maps of deposit obtained using an applied current density of 150 mA/m2 for 7 days: a.

SE image; b â&#x20AC;&#x201C; e. Single EDX maps for Mg, Ca, Fe and O respectively. (e). Single EDX element map of distribution of O

(e). Single EDX element map of distribution of O.

Percentage of Element

Applied Current Density (mA/m2)

Carbon

Oxygen

Sodium

Magnesium

Silicon

Sulfur

Chlorine

Calcium

Iron

Open circuit

4.82

64

1

0.87

-

0.25

0.39

-

28.68

50

8.08

63.55

1.41

4.08

0.3

0.7

1.99

1.67

18.22

100

20.18

53.04

1.25

2.12

-

0.4

0.12

5.95

16.92

150

17.48

52.35

1.35

3.96

0.25

0.4

1.8

7.74

14.67

Table 1. The relative percentages of various elements obtained using EDX quantification, of surface film deposits on steel samples at different applied current densities after 7 days immersion in artificial seawater.

Lower frequencies

Z" Higher frequencies

Router

Ca rich

Fe oxide

Mg rich

(b) Schematic of cross-section of deposit formed in cathodically under protection situation.

Rs

RS

Mg

Rinner

R

Z'

Couter Router

Cinner Rinner

Wc

(c) Cdl = interface reaction; Ra = anodic charge transfer resistance; Wc = cathodic Warburg

Ra

(a) Schematic diagram of complex plane plot (Nyquist plot).

Figure 3. Interface impedance model of deposit on mild steel in artificial seawater for underprotection.

46 Corrosion & Materials

s

Cdl

Based on experimental impedance plots, SEM and EDX results, we suggest that the plot given in Figure 3(a) represents calcareous film deposition on a mild steel surface, and a schematic diagram of sections of calcareous deposits formed on under-protected steel is presented in Figure 3(b). Our film in Figure 3(a) as well as the solution resistance Rs, consists of two layers: the outer layer Louter is a calcium rich layer; and the inner layer Linner is a magnesium rich layer. These are represented by the high frequency region in Figure 3(a). From the equivalent circuit given in Figure 3(c), the outer layer Louter is considered to be porous and is characterized by a parallel combination of a capacitor Couter that is directly associated with the thickness of the calcium containing deposits, and a pore resistance Router that is defined by the resistance of all of the pores. The inner compact layer Linner and the corroding interface are introduced into the equivalent circuit which is in series with Router. The Linner is also characterized by a parallel combination of a capacitor Cinner and a resistance Rinner. The corroding interface is characterised by a parallel combination of a double layer capacitor Cdl, charge transfer anodic resistance Ra, and a finite length diffusional impedance Wc, which represents the cathodic process. The parameter WC-R, the charge transfer resistance was mainly used to evaluate the cathodic reaction level .

14000

current density 0 (free corroded) current density 50mA/m2 current density 100mA/m2 current density 150mA/m2

WC–R (Ω).cm2

12000 10000 8000 6000 4000 2000 0

24

48

72

96 Time (h)

120

144

168

Figure 4. Plots of values for the cathodic charge transfer resistance WC-R with increasing time at different applied current densities.

If we assume that WC-R is the charge transfer resistance and as such is inversely proportional to the corrosion rate, then we do seem to be looking at the changes in corrosion rates with time and current density. The differences between

the open circuit and 50 mA/m2 rates are not as marked as the weight loss data, Figure 4; however the higher current densities show a marked increase in resistance indicative of a reduction in steel corrosion rate.

In the open circuit and 50 mA/m2 cases (Figure 4 and Table 2), we are obviously looking at an unprotected and underprotected surface where the charge transfer processes are both the oxygen reduction reaction and the iron corrosion reaction. In these cases, the values of cathodic resistance with increasing time at various current densities are given in Table 2, and these range between 2000 - 6000 Ω.cm2. Overall, these findings indicate that the oxygen reduction reaction and the iron corrosion reaction are both happening at the same time. Both these reactions are taking place on an iron surface which is not too well covered by the calcareous film and is clearly corroding; as can be seen in the optical images obtained (Plates 1 and 2).

Considering next the values of cathodic resistance WC-R obtained in the case of using applied current densities of 100 mA/m2 and 150 mA/m2. It is evident from Table 2, that the values of cathodic resistance WC-R obtained at these three applied current densities increased concurrently with increasing applied current density. With the sole exception of the values obtained at 72 hours, all the values of cathodic resistance WC-R obtained at a current density of 150 mA/m2 were substantially higher than the corresponding values obtained at a current density of 100 mA/m2. This indicates that the surfaces were covered by a fairly good calcareous deposit.

Our weight loss data clearly shows corrosion to have ceased at these values. Photographic evidence shows slight browning of the surface at 150 mA/m2 (Plate 8). Again it is suggested that a film grows on the steel surface which is an oxygen barrier and we are seeing a reduction in the oxygen charge transfer resistance. However, at these current densities, over time, the film eventually begins to crack, and subsequently becomes less compact and as a consequence, WC-R begins to fall erratically. With further time, the film repairs and WC-R begins to climb again. This is our explanation of the longer term behaviour of the films at these two current densities. A slight indication of film fracture and repair was observed in the case of a current density of 100 mA/m2, but with the higher current densities of 150 mA/m2, the phenomenon was much more pronounced and obvious.

Applied current densities (mA/m2)

6h

24h

48h

72h

96h

120h

144h

168h

0 (open circuit)

2200

2900

3000

3500

2200

3400

3100

3300

2

50mA/m

3000

5800

4800

4300

4300

3700

2100

3300

100mA/m

3100

5200

6900

8100

6800

7300

7500

7900

150mA/m

7400

7400

8900

7900

9000

10000

8800

7800

2 2

Table 2. Values of cathodic charge transfer resistance WC-R (Ω.cm2) with increasing immersion time at the different applied current densities.

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Vol 36 No 6 December 2011

47

Underprotection of Mild Steel in Seawater, the Calcareous Film

3.1 SEM and EDX examination of sample/deposit cross-sections.

Plates 9-12 show the SEM micrographs and corresponding EDX element distribution maps for Mg, Ca and Fe at the same magnification, of the sample cross-sections at the 4 applied current densities. The dark green area is magnesium containing, the pink area is calcium containing, and the red region is base iron metal or iron oxide. Four values of current densities were chosen from our weight loss data because 100 mA/m2 was under protected, 150 mA/m2 is just fully protected, 200 mA/m2 is well protected, and 300 mA/m2 is possibly over protected.

Plate 9 shows a clear example of the way the magnesium containing deposit is interrelated with the underlying growing iron oxide. The magnesium is always found above this iron deposit and the reasons why this is the case may well involve the phenomenon of co-precipitation [11].

From Plates 9 to 12, it is evident from the structure and elemental composition of the deposit layers, that at the lower current density of 100 mA/m2 (Plate 9) [potentials of around -840 mV] the layers formed are well defined, intact and adherent both to the steel substrate and to each other.

Plates 10 and 11 show the elemental distributions for Mg, Ca and Fe over the cross-sections of the deposits obtained with applied current densities of 150 mA/m2 and 200 mA/m2 respectively. The thinner bottom layer is probably Mg(OH)2 and the thicker top layer CaCO3. These observations indicate that the Mg containing compound deposits first and the Ca rich compound deposits later. At the current densities of 200 mA/m2 and 300 mA/m2 (Plates 11 and 12 respectively), some cracks appear and it is perhaps reasonable to suggest that this phenomenon is due to hydrogen evolution from the steel. In this condition, the cathodic reaction of water reduction occurs.

Plate 9. Secondary electron micrograph and corresponding overlaid EDX element distribution maps for Fe, Mg and Ca formed after 7 days immersion at applied current density of 100 mA/m2.

Plate 10. Secondary electron micrograph and corresponding overlaid EDX element distribution maps for Mg and Ca formed after 7 days immersion at applied current density of 150 mA/m2.

Plate 11. Secondary electron micrograph and corresponding overlaid EDX element distribution maps for Fe, Mg and Ca after 7 days immersion at applied current density of 200 mA/m2.

Plate 12. Secondary electron micrograph and corresponding overlaid EDX element distribution maps for Fe, Mg and Ca after 7 days immersion at applied current density of 300 mA/m2.

48 Corrosion & Materials

Overall, the SEM and EDX results obtained of the samples at full cathodic protection levels revealed that the deposits were composed of two layers with a clear boundary. In Plates 10 to 12, the inner layer is Mg-rich, whilst the outer layer was Ca-rich.

4. Conclusions Corrosion rates were measured at various current densities less than the protection current densities Under underprotection conditions, magnesium hydroxide has been shown to be the preferred precipitating species and this is contrary to previous findings. It is thought this is due to co-precipitation of magnesium/iron hydroxides.

The Warburg diffusion model is applied to the cathodic process, mainly the oxygen reduction reaction. The parameter WC-R was used to evaluate the cathodic reaction level.

5. Acknowledgments One of us (YFY) would like to thank the Dorothy Hodgkin Postgraduate Award (DHPA) for provision of a research studentship during my PhD studies. The University of Manchester is also thanked for providing an EPSRC PhD Plus Award to YFY during 2010 - 2010.

6. References [1] Y. F. Yang, J. D. Scantlebury and E. Koroleva.

“Underprotection of mild steel in seawater and the role of calcareous film”. NACE Corrosion Conference, Atlanta, USA, March 2009.

[2] Y . F. Yang, J. D. Scantlebury and E. Koroleva.

“Underprotection of mild steel in seawater and the role of calcareous film”. Corrosion accepted.

HEMPEL (Australia) Pty Ltd 12 Fitzgerald Road, Laverton North, 3026 www.hempel.com

[3] Y . F. Yang, J. D. Scantlebury and E. Koroleva . “A study of calcareous deposits in artificial seawater by EIS and SEM techniques”, J Electrochem Soc. Sumbitted for publication.

[5] H . Davy. “Further researches on the preservation of metals by electrochemical means”, Phil. Trans. Royal Soc. 115, p328. 1825.

[6] R . A. Humble. “Cathodic Protection of Steel in Sea Water with Magnesium Anodes”. Corrosion. 74. pp358-370, 1948.

[7] J . C. Hudson. The Corrosion of Iron and Steel. Chapman and Hall. London. 1940.

[8] C . Deslouis, D. Festy and O. Gil. “Characterization of calcareous deposits in artificial seawater by impedance techniques - I./Deposit of CaCO3 in the absence of Mg(OH)2” . Electrochimica Acta. 43. (12-13). pp.18911901. 1998.

[9] C h. Barchiche, C. Deslouis, D. Festy, O. Gil , Ph. Refait, S. Touzain and B. Tribollet. “Characterization of calcareous deposits in artificial seawater by impedance techniques - II./Deposit of CaCO3 in the presence of Mg(II)”. Electrochimica Acta. 48. pp1645-1654. 2003.

[10] S. C. Chung, J. R. Cheng, S. D. Chiou and H. C. Shih. “EIS behavior of anodized zinc in chloride environments”.

Corrosion Science. 42. pp1249-1268. 2000.

[11] A. Packter and A. Derby. “Co-precipitation of magnesium iron III, hydroxide powders from aqueous solutions”.

Cryst. Res. Technol., 21. pp1391-1400. 1986.

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