Question: 

Q1: Table A.2 lists material types and individual alloy UNS numbers. UNS S31600 and S31603 appear below the listing for “”Austenitic stainless steel from materials type described in A.2″” S31600 and S31603 comply with the requirements for material described in A.2 Why are S31600 and S31603 listed separately from the other austenitic stainless steels?

Q2:Do S31600 and S31603 have different environmental limitations than other austenitic stainless steels?

Answer

A1-Clause A.2 materials permit less highly alloyed grades than S31600 and S31603.

A2-Yes

This question is in relation to NACE MR0175/ISO 15156-3 Table A.2

Reference: ISO 15156 Maintenance Panel Inquiry #2013-06

We can provide support with NACE MR0175 and austenitic stainless steels.