The Use of Electrochemical Impedance Spectroscopy (EIS)

The Use of Electrochemical Impedance Spectroscopy (EIS)

The February talk was on the use of Electrochemical Impedance Spectroscopy (EIS) as a predictive tool for coating lifetime, and was given by Dustin Traylor, Global Product Manager of Axalta Coatings Systems.   This was an excellent presentation which produced significant discussion amongst those attending. The concept was to raise awareness of new predictive modelling techniques for coating life and performance.  A new generation of high temperature coatings, in particular high glass transition temperature Fusion Bonded Epoxy (with a  Tg of 205 C), are being developed as a lower cost alternative to expensive alloy steels.  However, the highly-functional epoxy resin and ingredients in these new coatings can make interpretation of testing results difficult for coating specifiers. Dustin explored the benefits of using EIS after atmospheric testing to assess a coating’s life expectancy. The conclusion was that EIS did have a part to play in conjunction with accelerated weathering, Autoclave and Atlas Cell tests, to assist in the determination of expected coating life.  This technique has now been adopted by Aramco and Chevron and is gaining credibility as a useful tool in the pipeline market.

The  branch AGM was held ahead of the March  evening technical meeting, at which David Mobbs (Chair) delivered a short presentation on the achievements of the branch over the past year, including confirming that the move to Imperial College had increased attendance from 20-30 to 40-50 per meeting, and that our finances were good.  He outlined the steps being taken to obtain speakers to present new technology, new ideas and having more technical content, and noted that the membership affiliated to the branch amounts to 45% of Institute members, and 22 members qualified for 20 or 30 years long service pins.  He finished by thanking everyone for their support, and the speakers and committee members who give up their time voluntarily to make it all work.

Mark Stone of Sonomatic Ltd then gave a presentation
on the technology advancements in integrity management
of storage tanks.  The industry is well versed with non-intrusive inspection of vessels and pipework, but corrosion mapping of storage tanks has always relied on man entry and physical base plate inspection. However, the industry does not like working in confined spaces and there are moves towards zero-man entry over the lifetime of storage and process vessels. Mark explained that tank inspection plays a major role in effective integrity management of storage tanks, which historically has relied on emptying the tank and personnel entry for cleaning and inspection, and that the common method of using Magnetic Flux Leakage testing is not necessarily the most effective method of determining metal loss.  Sonomatic have developed a range of methods for inspection of these tanks while in-service, which  includes the use of traditional shell wall inspection using crawlers, coupled with a new technology to determine metal loss of the tank shell  using multi skip technology deployed around the outer chine of the tank.

The key element of this testing programme is the use of robotic cleaning and inspection of the floor – the tool is dropped through the tank fluids to the floor and remotely guided by use of sonar. Firstly the level of sludge is determined, and then the tool removes this and scans the base plates, the results of which are transmitted to a mobile unit outside the tank where a statistical analysis is carried out. The presentation included a case study of a field application.

Mark Stone of Sonomatic

This was an excellent presentation and there was a high level of discussion around the floor.  The chairman’s opinion was that the real value of this testing procedure was that it was an ‘iterative process’, whereby a tank farm operator could screen all the tanks and identify which were detected as the worst. On opening the tank and carrying out full base plate inspection it would be possible to check the model to see how accurate it was, and by the time the third tank had completed its full inspection, the model would be pretty accurate, and could be used in future with more certainly.

Quality Assurance

Quality Assurance

The Institute of Corrosion has always understood the importance of providing a high quality of service to its members and clients, and has therefore embarked on setting up a Quality Management System fully complying with ISO 9001:2015.  This was also a requirement by Highways England regarding ICATs approvals (Correx are also separately accredited to this standard for ICATS).

Our Quality System has been audited by LRQA and is now accredited with meeting the requirements of the ISO 9001:2015 Standard as shown on the certificate.   The QMS will be audited both internally and externally to ensure ongoing compliance with the Quality System and continuous improvement of our system.

CEOCOR Congress 15 – 18 May 2018

CEOCOR Congress 15 – 18 May 2018

Crowne Plaza Hotel, Stratford upon Avon

The conference and associated exhibition will cover recent research and experience related to corrosion and protection of internals and externals of pipes and pipelines in the drinking water, waste water and oil and gas industries.

The full Programme for this event can now be found on the congress website, http://www.ceocor2018.com, as are a registration booking form, and hotel contact details.

If you are involved in pipeline corrosion this is a must attend event.  Registrations are already at 70% of capacity. Have you booked yet?

Technical Guidance Documents

A collection of recently edited and up-dated technical guidance documents from the CED Coatings group has recently been published in the member’s area of the Institute of Corrosion website. Each document includes extensive referencing to relevant standards and other sources of information. A summary of these documents is presented here. Please note that to access the members area you will need to register or re-register by filling in the on-line form at https://www.icorr.org/members-area.
CED/CT01 Inspection and testing – Surface preparation and organic coating-related inspections  

This document discusses the purpose of inspection, the specific areas that a paint inspector might check, the relevant standards and methodologies, the reasons behind the various requirements, and the equipment used. Subject areas include: pre-coating (visual inspection, surface profile checks, extraction of soluble salts, surface cleanliness checks, ambient monitoring) and post-coating (coating thickness checks, adhesion testing, holiday detection). The focus is on those methods which are considered the best, or most commonly used, but an emerging test for post-coating corrosion protection monitoring, namely electrochemical noise measurement, is included as an Appendix.

CED/CT02 Surface Preparation Methods

CT2 provides an insight into the types of preparation methods that are available, the equipment used and how this is related to industry standards. The three common surface preparation methods, i.e. abrasive blasting, hand and power tool, and water jetting, are discussed, with particular attention given to water jetting, which is less well-known than the others. The advantages and disadvantages of each method are also highlighted.

CED/CT03 Organic coating application methods 

This document provides an insight into the available coating application methods and the equipment used. The various application methods described are: brush application, roller application, spray application (including air-, airless-, HPLV-spraying, auto-deposition, and rotating discs and bells), dip coating and flow coating.

CED/CT04 Paint: a definition and generic organic coating types

This document provides an insight into the generic organic coating  types that are available, highlighting the types and compositions of the coatings. It begins with a brief definition of what comprises a paint system and an outline of why, when and where anticorrosive  paint is used. It provides definitions of resins (e.g. alkyd, epoxy, polyurethane/acrylic urethane, vinyl esters, and silicone-based resin systems), pigments and extenders, solvents, additives (driers, thixotropes, UV absorbers, de-foamers, wetting agents). Some examples of complete paint systems (primer, stripe coat, intermediate coat or coats, and finish coat) are also given.

CED/CT05 TMS: Thermal metal spray 

CT05 defines the technique of thermal metal spraying, placing it in context and noting the relevant surface preparation standards. The methodology is then described in detail, including flame spray and arc spray. Properties such as abrasion resistance, galvanic protection, longevity and the permeability of thermal metal spray to water are discussed. This is followed by a section covering the appropriate uses of TMS, as well as noting where it is NOT recommended.

 

CED/CT06 On-site and off-site application of intumescent fire and corrosion protection coatings for steel structures

This document provides a definition of intumescent coatings and highlights the key issues concerning specification and use of the types of coating appropriate in particular contexts. It also covers, certification, development and handling of the coating, and preparation of the substrate surface, together with the advantages and disadvantages of off-site or on-site application.

An emphasis on the corrosion protection aspects of the intumescent system, and information on the types of system that will be effective in this context, are included in the sub-section on environment. A large number of sources of further information are included towards the end.

Presentation to the Yacht Designers and Surveyors Assoication

Presentation to the Yacht Designers and Surveyors Assoication

The professional Yacht Designers and Surveyors Association (YDSA) contacted the Institute, via the Northampton office, requesting us to present a one day informative course on corrosion of steel hulled craft in fresh water service.  This task fell to past President Trevor Osborne as being the most suitable on the basis that he was after all a small craft owner, albeit one with a plastic non corrodible hull.  The presentation took place on March 1st at the Aqueduct Marina, Church Minshull near Nantwich on the Shropshire Union Canal. 

In spite of the poor weather and driving conditions, the number of attendees exceeded twenty persons, all experienced and active members of the YDSA from around the UK.  The ICorr presentation covered multiple subjects all related to corrosion of small craft and narrow boats operating in fresh water, including pitting corrosion, crevice corrosion, galvanic corrosion, coatings and painting, cathodic protection, electrical isolation by decoupling of a.c. grounding and other subjects, some of which emerged on an ad hoc impromptu basis and were an aside to the prepared presentation. 

The material presented was prepared to provide a greater background understanding of issues related to corrosion in the day to day work that YDSA members do while surveying narrow boats and other craft around the UK, and overseas.  The issue of corrosion in pleasure and working boats is an important one and the YDSA are very active in investigative surveying. From post event feed-back it was clear that all who attended found the presentation and group discussion most useful, and that the learning outcomes will be put to good use in carrying out future surveys and preparing reports.

This was a long day, but a very worthwhile one spent in the company of a well experienced and professional audience.   ICorr look forward to again meeting with the YDSA to further their understanding of corrosion and our understanding of pleasure boats and related surveying practices.

The President Writes

The President Writes

Even though the weather seems to want to slow us down in the UK, the Institute continues to move forward at a pace.  The last council meeting which was held at the end of February in Northampton, was very lively indeed, and shows the passion that is held by council members for the Institute.  Further development plans are in motion and I hope that members are starting to see increased activity.    New dates are planned for the “Fundamentals of Corrosion” course in locations around the UK.  Branch activity is very encouraging, the informative and dynamic report from Aberdeen was a highlight!

Our search for a new home for the Institute is ongoing, and we are investigating a potential site as I write this.

The route to Chartered Status is moving along and if anyone would like more details on how to get involved with this, as either a mentor or candidate, please contact David Mobbs.  The new season of the Young Engineers Programme is in full swing, with our great thanks to CB&I in Paddington for offering a venue for this excellent initiative, and also thanks to the sub-committee of George Winning, Trevor Osborne and David Mobbs, for putting in the effort to run this.

In May, the CEOCOR Congress will be coming to the UK, Brian Wyatt is the current President and together with an ICorr committee headed by Steve Barke, have organised what looks to be a fantastic event, and when I last checked looked like we will be soon reaching capacity.  This is an event well worth attending if you are involved in the pipeline protection field.  I will have the pleasure of being there and I hope to see ICorr being strongly represented.

As a final reminder to all, if you would like to progress your professional standing with the Institute, then we would welcome any applications, and if you have any questions on this process please contact the Northampton office.

Sarah Vasey, ICorr President