Patent ID: 8551266
Filing Date: 2013-10-08
Classification: C22C,C22F,F05D

Abstract:
1. Method for heat treating a nickel base alloy, comprising the steps of: a) heating a nickel base alloy to at least its delta (δ) phase solvus temperature, and lower than its incipient melting temperature for a predetermined time sufficient to dissolve substantially all of the nickel base alloy's delta (δ) phase, and b) cooling the nickel base alloy to a temperature below the gamma prime (γ1) precipitation temperature at a rate sufficient to precipitate the alloy's chromium carbide and gamma prime (γ1) in a serrated grain boundary. wherein the nickel base alloy has the following composition in weight- %: Cr 17-21 C 0.01-0.05 Mn max 0.35 Si max 0.35 P 0.004-0.020 S max 0.0025 Mo 2.5-3.1 Nb 5.2-5.8 Ti 0.5-1 Al 1.2-1.7 Co 8-10 W 0.8-1.4 B 0.003-0.008 Cu max 0.3 Fe 8-10 balance Ni and normally occurring impurities.