ASME SEC. XII Forming strain requirement for High Alloy steel such as SA 240 TYPE 304

[K.P.M.]

In ARTICLE TF-4 OF ASME BVPC Sec. XII Ed.2021 requirement of forming strain is mentioned only for TYPE 201-1 or 201-2, TYPE 201LN, TYPE 204 austenitic alloy materials to avoid Post Fabrication Heat Treatment. For other austenitic alloys such as TYPE 304, 304N, 316 etc. what forming strain criteria should be followed to avoid Post Fabrication Heat Treatment?

 

[DriveMeNuts]

There are threads on this. My recollection of ASME VIII is that there are no requirements. If you want to derive some fibre elongation numbers for your own peace of mind, you can reverse engineer Div 1 Appendix 44 (cold stretched pressure vessels). Cold stretched vessels don't required PFHT. Formed heads are essentially cold stretched.
It is the nature of the material.

 

[EdStainless]

The 2XX alloys work harden much more than the 3XX ones.
They are also significantly less corrosion resistant.
Likely this combination lead to the limits.

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P.E. Metallurgy, consulting work welcomed