Institute News
The branch held its last technical meeting of the 22/23 season on 13th April, when Reza Beheshty, Subject Matter Expert in Materials Corrosion, Welding, & Coating, Fluor, presented on “Flow Accelerated Corrosion.
Flow Accelerated Corrosion (FAC) is primarily a corrosion process aided by the chemical dissolution of an internally formed iron oxide protective layer in carbon steel piping and process equipment, followed by its transportation into the bulk fluid in the direction of flow (generally unsaturated water and wet steam) by means of mass transfer. This results in wall thinning (up to 10 mm/y) until complete rupture, if not detected and/or remedied. It is a significant damage mechanism common to power plant and industrial steam cycle systems and has been a concern there for many years.
The rate of metal loss by FAC depends on a complex interplay of several parameters. The challenge is to find a functional relationship between the hydrodynamic severity of the flow (i.e., mass transfer rate) and the environmental parameters influencing the FAC rate, mainly fluid temperature, pH, and oxygen concentration. Also, the amounts of chromium, molybdenum, and copper in the steel are very important material factors in prevention of FAC.
Even though the main influencing parameters are well recognised, major failures are still occurring at the same locations that were found in the 1980s and 1990s. Power plant owners’ major concern is that the FAC problem seems to be fading away in the minds of plant operating management at many facilities as a result of retirements in the power industry, while new personnel simply do not understand the importance of FAC control. Besides understanding the positive combination effects of the FAC influencing parameters for managing FAC proactively, without the need for utilising expensive tools, are still not completely understood.
One of the most well-known, and effective predictive models, for calculating FAC rate, considering the various parameters influencing FAC, was proposed by Chexal & Horrowitz et al [1], as shown below.
FAC rate (thinning loss) = f(T) x f(pH) x f(O2) x f (a) x f(MT) x f(G) x f(AC)
Where the various factors represent, temperature effect (T), pH effect (pH), dissolved oxygen concentration effect (O2), void fraction i.e., steam quality effect, for two phase FAC only (a), mass transfer (i.e., flow rate and pipe diameter) effect (MT), geometry effect (G), and alloy content impact, i.e., effect of chromium, copper, and molybdenum content (AC).
The primary objective of this presentation was to refocus on different FAC mechanisms, and to understand the effects of each of these parameters (as indicated in above model), and postulate how the combination of these influencing parameters could positively result in controlling the FAC damage with an increased level of confidence with carbon steels, in the absence of specific and expensive FAC predictive tools.
[1] Technology development by the U.S. industry to resolve erosion-corrosion, B. Chexal, N. Dietrich, J. Horowitz, W. Layman, G. Randall, V. Shevde, Electric Power Research Institute, published by international working group on reliability of reactor pressure components, IWG/-RRPC-88-1, Corrosion and Erosion Aspects
in Pressure Boundary Components of Light Water Reactors,
September 1988.
The branch resumed its end of season social event, after a number of years, with a canal boat trip on the Regents Canal through London, on the 11th May.
The cruise started at Paddington where 33 local members and supporters boarded, and enjoyed a light snack, while we set off. Once underway, and as we passed Little Venice on the way to Camden, taking in the many varied views along the route, further refreshments, including sandwiches and cakes, as well as beverages from the bar, were made available to the guests. As the boat passed through the grounds of London Zoo, the guests looked out for the African wild hunting dogs, known as painted wolves, but as the weather was so warm, they must have been resting under trees, similarly African warthogs and the monkeys did not show. This did not spoil the enjoyment, as the guests focused on discussing the many subjects of the technical talks given during the 2022-23 season.
After passing the zoo we came to expansive landscaped gardens of stately mansion houses and classic modern villas, which contrasted with the industrial buildings, a power station, and historical architecture, including ornamental iron bridges such as the pillared Macclesfield ‘blow up’ bridge. Many of these villas are owned by famous musicians such as Ronnie Wood, Pete Townsend, and Noel Gallagher – if only corrosion could pay so much!
After turning at Camden, the boat made its way slowly back to Little Venice where everyone alighted, and agreed it was a very enjoyable trip, and that they looked forward to future social events in the coming years. This event was an outstanding success, and the branch would like to acknowledge the support from International Paints, without whom it would have been difficult to stage.
Reza Beheshty, Subject Matter Expert in Materials Corrosion,
Welding, & Coating, Fluor.
Onboard and Underway.
Institute News
D&P Coatings Limited
D&P Coatings, based in Ellesmere Port, England, offers an offsite blasting and coating service. Pipework, structural steel, tanks, and vessels, servicing the gas and oil industries are all processed on site at our factory in Ellesmere Port, where the directors have a combined 50 years’ experience, and the workforce have over 45 years’ experience in the blasting and coating industry.
On site facilities include a large shot blasting enclosure and a smaller booth for stainless steel items. Their facility has a loading and offloading capacity of 10T, four large coating workshops, and a large lay down area, all within their 85,000 square ft facility. The workforce has amassed a vast knowledge of the industry throughout the years, and produces the highest quality and standard of work within the specification guidelines. D&P Coatings has its own inspection department, which is accredited with ICorr and NACE. They have achieved ISO 9001, ISO14001, ISO45001 and CHAS accreditations.
Institute News
CED Day: The annual CED Working Day and Symposium, this year entitled ‘Corrosion Prevention in the 21st Century’, was held on Thursday, April 27, 2023, at the National Physical Laboratory (NPL), Teddington.
The day highlighted the need to share and transfer knowledge across all industries facing similar corrosion challenges. There were seven main talks and three working groups, led by Douglas Mills (coatings), Nick Smart (nuclear), and Steve Paterson (All Energy Group). This one-day meeting was the latest in a series of working days for the Institute of Corrosion’s Corrosion Engineering Division. Dr. Danny Burkle (Corrosion Testing Specialist – LBBC, Baskerville), Chair of CED, welcomed delegates to the meeting and introduced the speakers. He emphasised that the financial loss due to corrosion in the UK is 3.4% of GDP, or £77.5 M (comparable with defence at 2% or education at 4%). Danny thanked Nick Smart, the previous chair of CED, for his invaluable services over the past 15 years, and he presented him with a special award. Their shared vision is to bridge the gap between the CED and CSD divisions in future, to the benefit of both.
There then followed, ‘An introduction to NPL and NPL Activities’ by Gareth Hinds (Fellow and Science Area Leader, Electrochemistry Group at NPL), a past President of ICorr (2018–2020), the current President of the World Corrosion Organization (WCO), and Vice-President of the European Federation of Corrosion (EFC). Gareth outlined the history of NPL, founded in 1900, and active in corrosion research since 1924 (Guy Bengough (FRS) was an early scientist working there). Subsequently, Alan Turnbull, FRS, FREng, OBE, with 50 years of service at NPL, was introduced and applauded. The focus of government funded research at NPL is: net zero, offshore wind, nuclear waste disposal, and materials selection for these areas. Knowledge transfer includes: NPL corrosion guides, international standards, and industrial guidelines. NPL though continues to do a large amount of corrosion testing on behalf of oil and gas operators (separately, on a commercial basis).
Professor Alison Davenport (University of Birmingham) addressed the subject of “understanding localised corrosion’ and how this can improve corrosion prevention methods. The corrosion of metals in natural environments is a non-uniform process. Using synchrotron X-rays, water and metals are both penetrated, thus permitting mechanisms of formation and breakdown of passive films to be elucidated. A video study providing 3-D tomograms was shown. Rotating disc electrodes enable the growth of passive films to be followed via current transients over millisecond periods. These studies were necessary to assess the risk of fatigue failure in ageing aircraft, e.g., by atmospheric corrosion studies of NaCl deposits on Al-Cu-Mg alloys (AA2024). Similar methods were used to study the corrosion of stainless-steel containers used to store intermediate-level waste. The role of salt films in growing pits was described, along with their relationship to Pourbaix diagrams. At each point in a growing pit, it can be shown that the corrosion current is a function of metal ion concentration and the electric field through the droplet.
Dr. James Hesketh, (Principal Corrosion Science Consultant at Jacobs) spoke on ‘The corrosion of canisters during interim and deep geological disposal of radioactive waste’. There are three levels of radioactive waste: high, intermediate, and low (HLW, ILW, and LLW). Containers for LLW and ILW include unshielded, thin-walled stainless steel, concrete fabrications, and robust cast iron canisters, which have greater impact and fire-damage resistance. Intermediate storage items have been subjected to atmospheric corrosion over several decades. Key environmental parameters are % RH, surface chloride concentration, and time of wetness. Future deep geological disposal will provide permanent, safe disposal. One specification is KBS-3. However, a Swiss concept enabled progress to a more advanced stage. All present designs make use of a multi-barrier approach, comprising copper/carbon steel, with predicted lifetimes >10,000 yr. Despite the complexity and time-variation of corrosive environments, two distinct phases may be identified – early, ‘oxidic’ and long-term, ‘anoxic’. In-situ experiments involving boreholes were then outlined.
Alyshia Keogh (University of Manchester – PhD student) discussed her current research, on the ‘Effect of microstructure on localised corrosion and atmospheric stress corrosion cracking of 15-5PH stainless steel’. The type of microstructure influenced the susceptibility and was very dependent on the ageing temperature, 450 °C, 540 °C or 650 °C. Microstructural characterisation was carried out by STEM/EDX, and differences in pitting behaviour were assessed using double loop electrochemical potentiokinetic reactivation (DL-EPR), which found a linear trend in degree of sensitisation with ageing temperature, and which correlated with the increase in the presence of Cr carbides. Electrochemical noise measured by galvanically coupling dissimilar microstructures suggested that the higher temperature ageing treatment produced the most metastable pitting events. This may have a higher probability of transitioning to stable pitting. Four-point bend specimens with Cl- salt deposits exposed to controlled temperature and humidity revealed that higher ageing temperatures were more resistant to cracking. The mode of cracking changed from intergranular at 450 °C to mixed-intergranular and transgranular, at 540 °C, whereas no cracks occurred in samples aged at 650 °C.
After an excellent lunch there followed several further talks, including one by Roger Francis himself, together with a presentation of the Paul McIntyre Award to him, a very worthy winner. This award is among ICorr’s premier awards, and is presented to a senior corrosion engineer, who, as well as being a leading practitioner in their field, has advanced European collaboration and international standards development.
Roger has been a corrosion engineer for over 45 years, working in the fields of marine corrosion, desalination, sour oil and gas corrosion, mineral processing, and the chemical and process industries. He has published over 100 technical papers in all these areas, written six books on various aspects of corrosion, and jointly edited three others.
Dr. Steve Paterson, (Materials and Corrosion Adviser, Arbeadie Consultants Ltd.) then presented on ‘Applying materials experience from oil and gas production to carbon capture and storage’. Carbon Capture and Storage (CCS) processes prove challenging in so far as the CO2 source may contain impurities, and processing is determined by the level and type of these. Problems encountered in transporting the fluid include liquid dropout, corrosion, and running ductile fracture. Joule-Thomson cooling causes low temperatures with an attendant lack of toughness, the preferred option is to avoid drop-out. Essentially, it is important to consider transients/unstable conditions when assessing processes and defining CO2 specification limits. Also discussed were low temperature brittle fracture and hydrogen-related cracking mechanisms, Stress Corrosion Cracking (SCC), the use of corrosion-resistant alloys, the application of downhole barrier valves, and non-metallic materials.
Dr. Jonathan Mann (Nuclear structural integrity engineer, Jacobs) gave an entertaining but most important talk entitled ‘How to make trends and influence people’ which focused on how fatigue damage is increased by corrosive environments, and is a key consideration in numerous industries, including nuclear. Fatigue crack growth (FCG) studies had been initiated by Rolls-Royce and supported by Jacobs. Current predictive methods are fairly simple, providing over-conservative results. An improvement was to move to a better model, that reflected real behaviour. The ASME Environmental Fatigue document provides fatigue and FCG data for austenitic stainless steels in PWR water (low dissolved oxygen), and an equation relating fatigue life to temperature, strain rate, and oxygen concentration was given. Other factors affecting fatigue life include, varying amplitude, load, multi-axial loading, surface finish, material variability, non-isothermal loading, and thermal gradients. Consequently, rigs have been designed to investigate any type of waveform over a wide-range of temperatures.
Dr. Roger Francis, (Director at RF Materials) gave a resume of ‘The limits of copper alloy and stainless-steel heat-exchanger tubes’. Common alloys used for heat exchangers are, copper alloys (w/o), Al-brass, 90Cu/10Ni, 70Cu/30Ni, and 66/30/2/2 Cu-Ni-Fe-Mn, plus stainless steels, 304L, 316L, 20Cr/18Ni/6Mo; 2304 and 2205 duplex plates, Z100 and 2507 super-duplex. Erosion-corrosion and pitting/crevice corrosion are encountered.
With Al-brass erosion ’horse-shoe going upstream’ defects occur at velocities of 1.5 – 2.0 ms-1. Where seawater contains chlorine to prevent fouling, minimal concentrations should be used. If silt is present, corrosion rates rise rapidly with silt content. However, titanium shows no erosion-corrosion over the entire range of silt levels. For copper alloys, crevice corrosion is not a significant problem, and pitting corrosion is not problematic in fresh water. Sulphide ions at 0.1 mg/l cause pitting corrosion but may be mitigated by acid-cleaning. Super-duplex steels have demonstrated excellent corrosion-resistance since the early 1990s.
Dr. Anthony Setiadi (Chief Consultant / Associate Director – Wood Thilsted) presented finally on the ‘Benefits of using corrosion protection for offshore wind’. Monopiles (MPs) widely used in the supply of renewable energy presently range from 8–10 m diameter and 90 m high. However, for future MP’s, 15 m diameter and 120 m high are envisaged. MPs operate in 15 – 60 m water depth, deeper waters require jackets or floating foundations. In any case, increasingly large surface areas are involved. Corrosion protection via materials selection, corrosion allowances, coatings, and CP for sea-water immersed areas, were discussed. Coatings and cathodic protection support a large decrease in the tonnage of steel required for these structures. Percentage steel tonnages were compared to a ‘base cost’ and tables were presented for 25, 30 and 35-year timescales for C1, C2, C3, and C4 environments.
Typical losses (kg y-1 m-2) ranged from 1.56 in C5 to 0.624 in C4 environments. It should be noted that the coating type can impact corrosion protection very significantly as does control of application at build. Finally, the need to consider the different climates encountered was discussed: tropical, sub-tropical, temperate and arctic.
It was possible later in the day for participants to visit the extensive corrosion laboratories of NPL.
All CED presentations will be uploaded to the ICorr website for members to view and download. The three working groups will continue to advance their activities and will announce dates for further meetings in due course. To find out about next year’s CED event, or if you are interested in attending, speaking, or exhibiting, contact Dr. Danny Burkle, at danny.burkle@lbbcbaskerville.co.uk The CED is actively recruiting for a vice chair to assist Danny with growing the division. If this is of interest to you or a colleague, please contact Danny and let him know. Corrosion Management is most grateful to Dr David Nuttall, FICorr and Dr Douglas Mills, FICorr, for providing this event write-up.
Presentation to retiring CED Chair Nick Smart, By Dr Danny Burkle, New CED Chair.
Professor Alison Davenport (University of Birmingham) addressed the subject of ‘understanding localised corrosion’.
Presentation of the Paul McIntyre Award to Dr Roger Francis by Stephen Tate, ICorr President.
Dr Gareth Hinds – Fellow and Science Area Leader, Electrochemistry Group conducts a tour of NPL facilities with ICorr guests.
Institute News
Dear Members,
A huge welcome to all those who have recently joined the Institute, or are in the process of upgrading their professional membership.
For anyone who has not yet renewed their membership, please do liaise with ICorr HQ, admin@icorr.org, who will be happy to help you, especially if your contact details have recently changed. If you have no changes, you can use our online link to renew, https://www.icorr.org/my-account-renew/
As you know, at this time of year we normally review all our subscription rates, however, with exceptional times upon us, we very much recognise some of you may be struggling with increasing financial pressures of late. Exceptionally, and in order to assist you through this difficult period, the ICorr Trustees will not be raising membership rates during 2023.
As an institute, we value every membership and will work hard to assist you wherever we can.
Much has happened since the last issue. Our YEP 2022 winners have recently returned from the AMPP 2023 Conference in Denver, Colorado, after an eye-opening experience learning from SMEs in the industry, making fantastic friends along the way, and gaining new confidence through the Leadership Training programme. We are extremely grateful to AMPP and BP (our key sponsors) in this regard.
During April, we held our hugely successful CED Working Day event at NPL Teddington, which so many enjoyed. Special thanks are due to Danny Burkle and Gareth Hinds, who were ably supported by all three working party chairs, and of course, all the presenters on the day, to make this a fantastic technical event. We were also very pleased to be able to make the Paul McIntyre Award to Dr Roger Francis in person, and to thank Nick Smart after 15 years of CED service as its chair.
Upcoming very soon, we have our Joint conference with the North of England Institute of Mining and Mechanical Engineers, on “Integrity Engineering for a Sustainable Future”, at the Neville Hall, Newcastle, Thursday 22nd – Friday 23rd June 2023. Do please register at Integrity Engineering for a Sustainable Future (NEIMME-ICorr Conference) Tickets, Thu 22 Jun 2023 at 09:00 on Eventbrite, or contact nechair@icorr.org
June will also see the roll-out of our new Online CP Bookings System (Dante), spearheaded by Eva Whittaker. Across all our Training Activities we are striving to achieve both growth and improvements to the range of our offerings. Please do check this out yourselves at: https://www.icorr.org/dante-course/
In August, we will once again be offering our Corrosion Awareness Day in Aberdeen, which has proved very popular in previous years. Register early at ICorrABZ@gmail.com if you would like to attend this, or receive other ICorr Aberdeen event communications.
All our branches are becoming increasingly active in the UK and we soon hope to have some Overseas offerings too!
On that very positive note, l will sign off and wish you all a great summer ahead.
Stephen Tate
President: Institute of Corrosion
