Effects of Stress Relief of 2.25%Cr 1%Mo material
Effects of Stress Relief of 2.25%Cr 1%Mo material
(OP)
What effect does increasing the cooldown period have on the hardness of the HAZ after welding and then stress relieving at 1200F for 1.5 hours.





RE: Effects of Stress Relief of 2.25%Cr 1%Mo material
If there is any effect it would be mechanical (strain).
RE: Effects of Stress Relief of 2.25%Cr 1%Mo material
Recent work by ORNL and EPRI on reheat aging of HAZ and its relationship to type IV creep cracking may provide some data on HAZ hardness and ductility/toughness as a function of cool down rate and wall thickness.
RE: Effects of Stress Relief of 2.25%Cr 1%Mo material
RE: Effects of Stress Relief of 2.25%Cr 1%Mo material
RE: Effects of Stress Relief of 2.25%Cr 1%Mo material
Per Mannesman/Vallourec, for SA335 P91 ( ferritic) the normal PWHT is from 1380 F, cooled at a rate of -280F/hr.
RE: Effects of Stress Relief of 2.25%Cr 1%Mo material
Lower critical for P91 is approximately 1490F. Depending on the Ni+Mn+N content of the filler metals used to weld P91, the lower critical can be below 1360 F.