Patent ID: 6315846
Filing Date: 2001-11-13
Classification: C22F

Abstract:
A process for heat treating an age hardenable nickel-base alloy to provide a yield strength in excess of about 145 ksi (1000 MPa) and improved low temperature ductility, the method comprising:(a) providing a worked material consisting of a Ni-base alloy consisting essentially of in % by weight: 55-63 Ni, 19-22.5 Cr, 7-9.5 Mo, 2.75-4 Nb, 1-1.7 Ti, 0.35 max. Al, 0.03 max. C, 0.35 max. Mn, 0.2 max. Si, 0.15 max. P, 0.01 max. S, trace amount of commercial impurities, and remainder Fe;(b) annealing the worked material at about 1825.degree. F. (996.degree. C.).+-.25.degree. F. (14.degree. C.) for at least about 1.5 hours to provide an annealed material; and(c) age hardening the annealed material by heating the material at about 1400.degree. F. (760.degree. C.).+-.50.degree. F. (28.degree. C.) for about 3.0 to 10.5 hours;furnace cooling the material to about 1200.degree. F. (649.degree. C.); andheating the material at about 1200.degree. F. (649.degree. C.).+-.50.degree. F. (28.degree. C.) for about 4.0 to 12.5 hours to provide an age hardened material.