Patent ID: 6068714
Filing Date: 2000-05-30
Classification: C22C,C22F

Abstract:
A process for making a forged nickel-base superalloy part for use in the 700-900.degree. C. range which comprises the steps of:a) providing a nickel-base superalloy having the following composition: percentage by weight  Cr 15.5-18 Co 14.0-15.5 Mo 2.75-3.25 W 1.00-1.50 Ti 4.75-5.25 Al 2.25-2.75 Zr 0.025-0.050 B 0.01-0.02 C 0.006-0.025 Cu .ltoreq.0.10 Mn .ltoreq.0.15 Fe .ltoreq.0.50 Si .ltoreq.0.2 P .ltoreq.0.05 S .ltoreq.0.05 Ni balance  and eventual impurities, wherein the weight ratio B/C is equal to or greater than 1.1;b) forging said nickel-base superalloy to obtain an as-forged part;c) submitting the as-forged part of step b) to a solution heat treatment at a temperature ranging from 10 to 30.degree. C. above the .gamma.' phase solvus temperature;d) quenching the solution heat treated forged part resulting from step c) at a quenching rate above 100.degree. C./minute;e) submitting the part resulting from step d) to a first heat aging at a temperature ranging from 650.degree. C. to 750.degree. C. for at least 16 hours; andf) submitting the part resulting from step e) to a second heat aging at a temperature of 800 to 850.degree. C. for at least 4 hours.