London Branch News

The next meeting of the branch is a joint meeting with Society of Chemical Industry (SCI), being held at the SCI offices, 14/15 Belgrave Square, London, on 26 September at 17.30. The theme of the evening is “Offshore Energy and Telegraph Cables” and will be chaired by John O’Shea, Hon Life Fellow, ICorr.
Dr Fred Parrett, SCI London Group, will present the story of the first transatlantic telegraph cable, the story of how it happened and the personalities involved. The second presentation will be by Trevor Osborne, a Past President of ICorr, who will discuss the problems which occurred with the installation of offshore wind farm towers, and how, what should have been an easy transition from the early offshore oil and gas platforms, often was not.
Places are limited, so register your interest at http://bit.ly/Offshore_Energy, or email conferences@soci.org
The branch is still looking for a new home for the 19/20 evening meetings, and full details will be emailed to regular branch attendees, and posted on the Institute website once the venue is known.

London Branch AGM

London Branch AGM

The branch AGM was held in March, which was followed by the “President’s talk”. The chairman, Paul Brook, reviewed the activities of the branch over the past year and noted that we had had excellent presentations. The Treasurer, Jim Glynn, announced that again our finances were in good shape, and that surplus monies will be returned to head office.  Paul then asked if any members wanted to join the committee, and confirmed that existing members were happy to serve for another year.   Paul also informed the meeting that the branch is close to completing a venue move from Imperial College, Kensington to the IMechE offices in Bird Cage Walk, Westminster.  This should be a great home for London branch future technical talks, which will restart following the summer recess in October, on the second Thursday of the month as usual. More details will be available on Institute web site in due course.

Gareth Hinds then presented his views on  the future of the Institute, and discussed ways we could adapt to changes, including environmental challenges, the rise of digital communications, and how to encourage more young engineers to join the Institute, and how to support them. This generated a lot of discussion and interesting suggestions.

The April meeting, the last of this season, was joint with The Welding Institute, and was given by Alan Denney of TWI, on the subject of “High tensile steel bolts and nuts: hydrogen embrittlement and failure in corrosive environments.’

Alan started by talking about the failure of threaded components used as shear connectors for earthquake resistance on the San Francisco Oakland Bay Bridge, which has been well documented in the technical press in the USA. These galvanised rods (in ASTM A354 grade BD steel) were pre-installed in 2008 in the supporting piers to the bridge superstructure which are above the water level. The superstructure was assembled and in 2013 the rod connectors were pre-tensioned hydraulically to 70% of UTS. A number of these suffered brittle failure, the published cause of which was that the rods failed due to hydrogen embrittlement arising from stress corrosion cracking.

Alan then proceeded to explain the conditions required for stress corrosion cracking, namely a combination of a susceptible material, a source of the hydrogen,  and tensile strength above a threshold value. He explained that the hydrogen could be either from internal sources in manufacture, or from an external source. The potential sources in manufacturing include hydrogen retained from steelmaking or hydrogen resulting from pickling of the components prior to coating. The external source would result from corrosion, the hydrogen being generated by the cathodic reaction. He explained that failures can occur in nuts as well as the bolts or threaded rods, and that in galvanized components
the zinc acts as a barrier to the outward diffusion of any trapped hydrogen.

Failures of structural bolts have a long history. Alan mentioned that his first encounter with bolts failing from hydrogen embrittlement was in the 1970s on a television transmission tower, with failures occurring in V grade and Y grade bolts on cold nights; the bolts being found on the ground in the morning, and his most recent experience of a failure was a few weeks before this talk. Apart from in transmission towers, such failures have also occurred in the recent past on prestigious building structures, and in offshore wind turbine towers. Recent occurrences known to Alan have been in large diameter high tensile bolts, generally in bolt grades 10.9 and above. He explained that there was a relationship with hardness of the fasteners (both bolt and nut), and covered recommendations in standards such as those published by DNV-GL for offshore wind turbine structures, which limit the highest strength grade to 10.9. He discussed the typical crack morphologies associated with hydrogen embrittlement and how the fracture surface could be ‘read’.

Alan then discussed some of the metallurgical aspects in bolt and nut materials and the recommendations and findings of work carried out by the Deutscher Schraubenverband (DSV) in relation to the desirable elements in the composition, and their proposed limits on chemical composition. He presented some findings from DSV on the failure thresholds in 10.9 bolts under ASTM F1624 test conditions with different coating types and then finished by summarising the findings:

n There is a risk of stress corrosion cracking with the use of fasteners with a UTS > 1000 N/mm2 in a corrosive or marine environment.

n The much-quoted guideline of 380 Hv as the threshold for stress corrosion cracking is not conservative, notably when there is a risk of external corrosion, even during temporary conditions.

n Controls which will improve their performance in marginal situations can be put in place for the bolt materials, their heat treatment and metallurgical controls, their coating systems and application, and their quality control and testing requirements .

However the main means of avoidance of SCC is to control the environment.

There was a lively question and answer session, with interesting contributions from the audience and the meeting was closed with a vote of thanks and a presentation to
the speaker.

Offshore Energy and Telegraph Cables

Organised by SCI’s London Group and the Institute of Corrosion – London Branch
The Evening Chair will be John T O’Shea, Hon ICorr Life Fellow

Thursday 26 September 2019, 17:30 for 18:00
SCI, 14/15 Belgrave Square, London, SW1X 8PS, UK

Book today! Free registration
E: conferences@soci.org
T: +44 (0)20 7598 1561
https://www.soci.org/events/offshore-energy-and-telecommunication-cables

This evening event includes two presentations, followed by a networking reception at 19:30. Attendance to this
event is free of charge, however places are limited. Please register today by visiting: http://bit.ly/Offshore_Energy
The event is open to SCI, ICorr, IOM3, LMS, and TWI members and guests.

Please click link below for details of the event:

Offshore Energy and Telegraph Cables – flyer

London Branch

London Branch

The February talk was by Dr Bijan Kermani of KeyTech, on corrosion, the outlook, challenges and future of the discipline, particularly in regards to hydrocarbon production. Having briefly touched on the economics of corrosion in the oil and gas industry, Bijan went on to present an overview of the projected global energy mix over the next two to three decades, highlighting that there is an increasing global energy demand and that hydrocarbons will contribute the majority of this. He emphasised that technology continues to play a fundamental role for the hydrocarbon industry sector’s business success, reducing capital and operational expenditure, environmental, safety and reputational risk, and increasing reliability. He emphasised that innovative materials, corrosion and integrity management technologies play a significant role in supporting this. He argued that while significant progress has been made over the years in understanding the root causes of integrity management threats with advances in technology and expertise, there still remains major challenges.

The talk covered three themes including (i) a technology outlook in energy, (ii) corrosion and materials challenges facing hydrocarbon production industry sector, and finally (iii) what is required to move the corrosion and metallurgy discipline forward. In this, a brief reference was made to the corrosion discipline with respect to future priorities to attract a new generation of high calibre professionals. It was said that our contributions to all aspects of social, environmental, safety and security are clear and that the discipline has had significant achievements. The key achievement is the provision of public welfare; a ‘positive image’ rather than the reduction of failures which may convey a negative image of our discipline. By this change of focus we can attract even a better generation of young students.

Bijan concluded that the future is bright, although many challenges remain and there is a growing requirement for innovative solutions with timely implementation to achieve next level performance.

London Branch News

London Branch News

The January talk by Dr Patricia Conder, Sonomatic Ltd, was on “Pipework Corrosion: Prediction and Reality”, and how differences in the spatial pattern of internal pipework corrosion, be it patchy or more uniform, impacts on the effectiveness of inspection, and how this can be used to improve understanding of the underlying corrosion behaviour. Patricia discussed how extensive corrosion is easy to find and measure, but in instances where wall loss occurs more randomly, the challenges of matching inspection strategy to the corrosion coverage increase. She discussed how thinking of inspection of as a statistical sampling process helps both inspection strategy and analysis. The audience were challenged to spot the difference between a corroding and non-corroding circuit 
within a second. This was successfully achieved by 
means of a graphical overview of the whole circuit inspection history.

This overview presented a route to mine into the data, to examine “groupings” based on corrosion mechanisms, for example testing to see if the bends really are corroding faster than the straights. She also discussed the use of integrity driven corrosion rates, based on how the overall wall loss of the circuit is changing, rather than focussing on per inspection location corrosion rates, which can exaggerate measurement variability. Although historically inspection has been based on manual ultrasonic thickness measurements and radiography, these techniques have only covered relatively small areas overall. Developments for pipework inspection offer everything from screening to more detailed high accuracy mapping. The challenges being to incorporate all these results into a database in a meaningful way to get added value from a change in inspection approach. Patricia finished the talk by reminding us to think corrosion: think spatial.

Pipework Corrosion- Prediction and Reality

Dr Patrica Conder receiving a token of appreciation from Trevor Osborne, together with Paul Barnes, branch chairman

The January talk of ICorr London branch by Dr Patricia Conder, Sonomatic Ltd, was on “Pipework Corrosion : Prediction and Reality”, and how differences in the spatial pattern of internal pipework corrosion, be it patchy or more uniform, impacts on the effectiveness of inspection, and how this can be used to improve understanding of the underlying corrosion behaviour.

Patricia, discussed how extensive corrosion is easy to find and measure but, in instances where wall loss occurs more randomly, the challenges of matching inspection strategy to the corrosion coverage increase. She discussed how thinking of inspection of as a statistical sampling process helps both inspection strategy and analysis. The audience were challenged to spot the difference between a corroding and non-corroding circuit within a second. This was successfully achieved by means of a graphical overview of the whole circuit inspection history.

This overview presents a route to mine into the data, to examine “groupings” based on corrosion mechanisms, for example testing to see if the bends really are corroding faster than the straights. She also discussed the use of integrity driven corrosion rates, based on how the overall wall loss of the circuit is changing, rather than focusing on per inspection location corrosion rates, which can exaggerate measurement variability. Although historically inspection has been based on manual ultrasonic thickness measurements and radiography, these techniques have only covered relatively small areas overall. Developments for pipework inspection offer everything from screening to more detailed high accuracy mapping. The challenges being to incorporate all these results into a database in a meaningful way to get added value from a change in inspection approach. Patricia finished the talk by reminding us to think corrosion: think spatial.