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