Abstract: A heat treatment for hot or cold worked 725 corrosion resistant Ni-base alloys to increase the room temperature yield strength of the material to above about 140 ksi (965 MPa). The material is useful for oil patch and gas turbine applications. The process includes annealing the material at about 1825° F. (996° C.) for about 1.5-4 hours, age hardening the material at about 1400° F. (760° C.) for about 3.0 to 10.5 hours to precipitate double gamma prime, furnace cooling the material about 50° F. (28° C.) to 100° F. (56° C.) per hour and heat treating the material at about 1200° F. (649° C.) for about 4.0 to about 12.5 hours.

Abstract: The alloy consists of an age hardenable-corrosion resistant alloy useful for oil and gas applications that require resistance to low-level sour gas conditions. This alloy contains, by weight percent, 20 to 36 nickel, 18 to 25 chromium, 1 to 8 molybdenum, 1.2 to 4 titanium, less than 0.5 aluminum, 0.001 to 0.5 carbon, less than 1.5 niobium, less than 10 manganese, less than 5 copper, less than 4 cobalt, less than 0.1 total calcium, cerium and magnesium, 0 to 0.01 boron and balance iron and incidental impurities and deoxidizers.