Patent ID: 8470106
Filing Date: 2013-06-25
Classification: C21D,C22F

Abstract:
1. A heat treatment method for desensitizing a nickel-based alloy with respect to environmentally-assisted cracking in a nuclear reactor environment, the alloy consisting of the following composition in percentages by weight: C≦0.10%; Mn≦0.5%; Si≦0.5%; P≦0.015%; S≦0.015%; Ni≧40%; Cr=12%-40%; Co≦10%; Al≦5%; Mo=0.1%-15%; Ti≦5%; B≦0.01%; Cu≦5%; W=0.1%-15%; Nb=0-10%; Ta≦10%; the balance being Fe, and inevitable impurities that result from processing, the method comprising: holding the alloy at a temperature in the range of 950° C. to 1160° C. in an atmosphere of pure hydrogen or containing at least 100 ppm of hydrogen mixed with an inert gas for a duration until the nickel-based alloy is desensitized to environmentally assisted cracking in a nuclear reactor environment, the nickel-based alloy being considered as desensitized to environmentally assisted cracking in a nuclear reactor environment if a fractured surface of the nickel-based alloy is either purely ductile transgranular or both ductile transgranular and intergranular as determined by traction tests performed in air at 650° C. at a speed of 10