United Technologies Corporation

Timothy P Fuesting

William J Gostic

Charles M Biondo

Paul D Genereux

John A Miller

Roy L Athey

A process for producing a fine grain forged superalloy article having a high yield strength at intermediate temperatures. A preferred starting composition comprises, by weight, 15% Cr, 13.6% Co, 4.1% Mo, 4.6% Ti, 2.2% Al, 0.01% C, 0.007% B, 0.07% Zr, balance Ni. This material is forged at a temperature above the gamma prime solvus and at a true strain of at least 0.5. Alternately, the material may be forged below the gamma prime solvus temperature with intermediate super solvus anneals. The overaged material is then worked at a temperature below the gamma prime solvus. The resultant fine grain material is then heat treated or can be further isothermally forged prior to heat treatment to produce complex shapes.

Superalloy forging process

Superalloy castings having large variations in section thickness are heat treated using a cyclic stress relief procedure, with the temperature being cycled between about 50.degree. F. (28.degree. C.) and 150.degree. F. (83.degree. C.) below the second phase particle solvus temperature, to relieve the residual stresses incurred during cooling within the mold following casting, followed by a solution cycle at a temperature about 25.degree. F. (14.degree. C.) below the second phase particle solvus temperature to dissolve some or all of the second phase particles.

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Lynchburg, VA, United States of America

Timothy P Fuesting