Allowable stress for non standard material (ASME section 8 Div-2)

[MDKARMD]

How to arrive allowable stress per ASME Section 8 div-2 based on yield strength and ultimate stress. what is the code reference.
I wanted to use the modified material (by quenching and Hardening),the UTS&YST modified to 105ksi&85ksi , what are the code reference for this??? how much allowable can be considered???

 

[TGS4]

Unlisted material is not permitted in ASME Section VIII, Divison 2. If you wish, there is a procedure to have a new material incorporated, either via a Code Case or directly into Section II, Part D.

 

[MDKARMD]

thnks..

material is listed in asme ,but i m modifying the UTS and yield value ,in this what is the recommended procedure or relation to arrive allowable stress(S)??
my vessel is not certifying to ASME.

 

[TGS4]

If you're not certifying the vessel to ASME (U-stamp), then you can pretty much do whatever you want (subject to your insurers' requirements, plus the local jurisdictional requirements, and of course your clients' specification). What you are proposing does not comply with ASME.

I would ensure that the values of yield and ultimate are uniform and isotropic. The procedures for calculating S are contained in ASME Section II, Part D, Appendix 10.