Corrosion of duplex stainless steels at elevated temperatures
Wed, 24 December 2003
RECENT piping failures offshore have identified a need for long-term protection from external chloride stress-corrosion cracking (SCC) of duplex steels operating at temperatures in excess of 90 degrees C.
One possible solution is the application of a thermally-sprayed aluminium (TSA) coating. To date the suitability of such a coating has not been evaluated systematically for use with duplex stainless steels, and a joint-industry project being has now been set up by The Welding Institute to undertake such an evaluation.<.P
The main objectives of the project are:
to evaluate the application of TSA coatings for prevention of external chloride corrosion cracking and pitting/crevice corrosion of welded and plain duplex stainless steels;
to develop relevant corrosion test procedures and test coupon design;
to demonstrate the application of TSA to occluded geometries;
to produce key recommendations for the specification of TSA to duplex stainless steel.