Understanding ISO 15156-3 Table A.2 and Dual-Certified 316/316L Stainless Steel

ISO 15156-3 Table A.2 and Cold Work Restrictions for 316L NACE

Under ISO 15156-3 Table A.2, austenitic stainless steels are categorized based on their environmental limits for use in sour service. In the notes section under subheading ‘b’, which applies to grade UNS S31603 (316L) specifically, there is a statement that the material must be free from cold work caused by shaping, forming, cold reducing, tension, expansion, etc. after the final solution annealing and quenching treatment. This statement was added after a successful ballot to extend the use limits of UNS S31603, and it was accompanied by a more descriptive definition of what constitutes cold work.

However, it may be unclear why this statement only applies to UNS S31603 and not to other types of austenitic stainless steels described in paragraph A.2 (under subheading ‘a’ above).

Dual-Certified 316/316L Stainless Steel and ISO 15156-3 Table A.2

If a material is dual certified as 316/316L (UNS S31600/S31603), it falls under both categories ‘a’ and ‘b’ as applicable. This is because the environmental limits given for low carbon 300 series stainless steels, such as S31600 (316) and S31603 (316L), are acceptable for the dual certified grades.

In summary, understanding ISO 15156-3 Table A.2 and the restrictions on cold work for 316L NACE is important for ensuring the proper use of austenitic stainless steels in sour service. Additionally, dual-certified 316/316L stainless steel falls under both categories ‘a’ and ‘b’ as applicable, making it a versatile option for use in various environments.