In NACE MR0175, are austenitic and duplex stainless steels acceptable “as welded”? or do they need PWHT?
For the cast austenitic and duplex stainless steels there is no specific mention of a requirement for post weld heat treatment in Part 3 that discusses welding of these alloys. However, there is a statement in the application of these alloys that they are only acceptable in the solution annealed and quench condition. In my opinion, the as welded condition does not meet the intent of being solution annealed and quenched. So can these alloys be used in the as welded condition?
These alloys can be used in the as welded condition provided they meet the requirements of Paragraph 6.2 of ISO 15156-3 and the corresponding Tables in Annex A. In particular Paragraph 6.2.2 indicates that welding PQRs shall include documented evidence of satisfactory cracking resistance.
This question is in relation to NACE MR0175/ISO 15156-3 Clause 6.2.2
Reference: ISO 15156 Maintenance Panel Inquiry #2009-03
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