Patent ID: 7217330

Claim:
A method of heat treating a turbine rotor disk varying in cross sectional shape from a relatively thick radially inner portion to a relatively thinner radially outer portion to obtain different radial properties at different radial locations in the rotor disk comprising: a) heating the rotor disk for a period of from 4 to 10 hours at a temperature of 1800° F.; b) cooling the rotor disk to a temperature of about 1550° F. at a rate of from 1 to 5° F./min; c) holding the rotor disk at a stabilization temperature of about 1550° F. for a period of from about 2 to about 4 hours such that radially outer portions of the disk are exposed to said stabilization temperature for longer periods of time than radially inner portions of the rotor disk; d) cooling the rotor disk to room temperature at a rate of 20°–40° F./min; e) precipitation aging the rotor disk by heating the rotor disk to temperature of 1325° F. for 8 hours, and f) cooling the rotor disk; wherein creep and creep crack growth resistance are enhanced at radially outer locations of the rotor disk and strength is enhanced at radially inner locations of the rotor disk.