awsbutch;
The "allowing" you are referring to is called allowable stress and this is based on code of construction. If this is for a pressure vessel, you can use ASME B&PV Code, Section II, Part D to find the allowable stress value (which is used to determine thickness of the component based on service temperature and dimensions) as a function of design temperature, and also the maximum permitted design temperature.

Thanks for your reply. You're right this material is possibly used for a pressure vessel (HIC-material, so called Dicrest) and is used in several thicknesses. However, the design T varies from minus 20 up to 230 degrees C with a designpressure of 9,5 B. I do not have the ASME code available, at least not within 24hrs and I have to reply tomorrow at the latest. The Y-strength of P265 at room T is 235 N/mm2 and at 230 degree C it is 195 N/mm2.

I understand that you need more parameters to define, however I need to know if SA516-gr60 has an equal design T.

I would appreciate your reply.

awsbutch,
The ASME SA 516 gr60 is "allowed" from -29 deg C to 340 deg C for an allowable design stress of 15,000psi, constant, no variation with the T. The minimum Y is 32,000psi and the maximum tensile is 60,000psi. These details are from the previous revision of ASME, are not in line with the 2007 revision. If desperate, I'll look-up the book and let you know the latest results.
cheers,
gr2vessels

Thanks for your reply. This is enough to get me started today.