Tuck Langley Alloys, Meighs Ltd (MCF Chairman)
Dent Bodycote (Vice Chairman)
Stokes MoD (DSTL) (Imm. Past Chairman)
Howarth Lloyds Register (committee)
Jacob- Corrosion Consultancy (committee)
Oakley QinetiQ (committee)
Peet Sheffield Testing Labs (committee)
Torrance Aish Technologies (committee)
Wood Southampton University (committee)
Tuck MCF Secretariat
Barik - Southampton University
Barraclough Commtech Associates
Bates DRB Materials Technology (speaker)
Blythe Southampton University
Chambers - Southampton University
Connolly University of Birmingham (guest)
Fowler Rolls Royce
Terry Harvey - Southampton University
Amira Kawar - Southampton University
Lawrence - KBR
Lee - TWI
Phillips Weir Pumps
Powel CDA & NI
Scales BAE Systems
Wilhelm Schleich KME Metal
Geir Magne Selvig Frese Metal (guest)
Klaus Steinkamp KME Metal
Mandar Thakare - Southampton University
Julian Wharton - Southampton University
Chris Amon Aker Kvaerner
Stuart Bond TWI
Peter Cutler - NI
Jagath Mawella Sea Technology (MoD)
The Chairman (Clive Tuck) opened the meeting.
Chairman also gave an update on the progress of the collaborative research
Secretariat presented the list and topics of forthcoming meetings.
Any member wishing to make a presentation was advised to volunteer soon,
while the programme was being finalised. She
also reminded members that CPD certificates were available after the meeting for
those who wished to use these meetings to build up their CPD portfolio.
A brief statement on the MCF accounts was given.
A brief statement on the MCF accounts was given.
[Click for abstracts]
2.1 Corrosion Performance of Nickel Aluminium Bronze (NAB) Under Seawater Immersion and Erosion-corrosion Conditions, Rakesh Barik, Julian Wharton & Robert Wood (Surface Engineering & Tribology Group, School of Engineering Sciences, Southampton University) & Keith Stokes (DSTL)
Welding Issues with Copper Alloys, Mike Gittos &
Chris Punshon (TWI), presented by Briony Lee
John Fowler asked whether anyone had experience of exposed carbon fibre
(in epoxy) against nickel aluminium bronze in seawater.
It was suggested that insulation might be looked at, although there was a
consensus that insulating with epoxy was difficult.
Information has been gathered by DERA on the subject, but this largely
concerns carbon fibre corroding aluminium.
There is a DERA report which advocates the use of glass, although this
would cause loss of other benefits.
Barry Torrance (Aish) mentioned that his company had been doing
experimental work on small signal frequency responses between ICCP elements, and
invited anyone interested to discuss this with him after the meeting.
Derek Bates (DRB Materials) had been looking at aluminium extrusions for
the marine industry. These were
anodised in a chromic acid bath, and there were resulting patchy anodised areas
with some black and some shiny. This
was not acceptable to clients, and a solution had not yet been found. Clive Tuck (Langley) said that this was a common problem,
particularly seen on the thicker parts and welds of aluminium extrusions (AlMgSi)
after colour anodising. It is
caused by high iron content. This
influences the size and distribution of the Al-Fe-Si phase particles which come
out on grain boundaries. It was
therefore necessary to be selective about the source of the aluminium.
Even if the overall average iron content of differently sourced samples
might be equivalent, the micro-structural form of the iron is a controlling
factor. The effect is also seen if
there is a high copper content, although it becomes less if a small amount of
nickel is present in the AlMgSi alloy.
Mike Lawrence (KBR) asked whether there was an acceptable method for the
preconditioning of a Cu-Ni pipework cooling system if it had been run with less
than perfect seawater and left damp for a while.
In such a case, once in service, it could already be corroded.
Is there any solution which can be washed through to improve the
situation? Wilhelm Schleich (KME)
mentioned that there were standards available:
781 Issue 3 Sep 1990 and VG 85004-8:1995 (in German).
Both standards deal with NaDDTC-treatments of the CuNi-Systems.
(This NES covers the process and procedure to be used to prevent
excessive corrosion of ships sea water system and heat exchangers due to use of
sulphide polluted sea-water during construction). In general, the content of both standards is similar.
However, the NES prescribes an electrochemical method for the evaluation of the
treatment quality, but the VG limits the evaluation to visual means only.
As to prolonged exposure of Cu-Ni pipe to polluted seawater, the Royal Navy heat treat Cu-Ni to improve its oxide film, and use resistance polarisation sensors to control iron anodes which are used to produce iron dosing of the system.
4.1 Long-term and Accelerated Corrosion Performance of Cast Nickel
Aluminium Bronze in Seawater, Robin Oakley and John Galsworthy (QinetiQ)
Part 1 :
Long-term and Accelerated Corrosion Testing Methods for
Copper-Based Alloys in Seawater,
R.S. Oakleya*, J.C. Galsworthya, K.R. Stokesb,
Part 2: Some observations made during the destructive examination of cast nickel aluminium bronze seawater system components after service, John C. Galsworthy and Robin S. Oakley, QinetiQ Ltd., Cody Technology Park, Farnborough, GU14 0LX, UK
4.2 Learning from Failures, Derek Bates (DRB Materials Technology Ltd)
The Chairman closed
the meeting at approx. 3:45 pm
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