Heat treatment for nickel-base superalloys

The present invention is directed to a heat treatment for nickel-base superalloys used to make single crystal parts and components for gas turbine engines. The heat treatment is conducted in a vacuum or inert atmosphere and includes the steps of solutionizing in a temperature range sufficient to achieve solution of at least 95% of the gamma ' phase, preferably 2385 DEG -2395 DEG F., for 2 hours; cooling to 2000 DEG F. at 100 DEG F./min minimum, furnace cooling to 1200 DEG F. in 60 min. or less and thereafter cooling to room temperature; heating to 2050 DEG +/-25 DEG F. for 4 hours; furnace cooling to below 1200 DEG F. in 6 min. or less and thereafter to room temperature; and heating to 1650 DEG +/-25 DEG F. for 4 hours and thereafter furnace cooling to room temperature.