Abstract: A method of forming a component from a gamma-prime precipitation-strengthened nickel-base superalloy so that, following a supersolvus heat treatment the component characterized by a uniformly-sized grain microstructure. The method includes forming a billet having a sufficiently fine grain size to achieve superplasticity of the superalloy during a subsequent working step. The billet is then worked at a temperature below the gamma-prime solvus temperature of the superalloy so as to form a worked article, wherein the billet is worked so as to maintain strain rates above a lower strain rate limit to control average grain size and below an upper strain rate limit to avoid critical grain growth. Thereafter, the worked article is heat treated at a temperature above the gamma-prime solvus temperature of the superalloy for a duration sufficient to uniformly coarsen the grains of the worked article, after which the worked article is cooled at a rate sufficient to reprecipitate gamma-prime within the worked article.

Abstract: A test method for testing the thermal mechanical fatigue performance of a test material includes preparing a test specimen of the test material, wherein the test specimen has a base, and a rib extending outwardly from the base. The test specimen is thermally cycled through at least one test cycle. In each test cycle the rib is heated to a higher rib temperature and thereafter cooled to a lower rib temperature. The test specimen is evaluated for thermal mechanical fatigue damage.

Abstract: In accordance with an embodiment of the present invention, a method for reducing residual stress in a nickel-base superalloy article comprising about 40-70% of gamma prime phase and having a gamma prime solvus temperature is disclosed. The method comprises the steps of super-solvus heat treating the superalloy article about 5-40° F. (3-22° C.) above the gamma prime solvus temperature; and holding at the super-solvus heat treatment temperature for about 0.25-2 hours, wherein the heat-treated superalloy article has reduced residual stress.

Abstract: An article made of a nickel-base superalloy strengthened by the presence of a gamma-prime phase is prepared by solution heat treating the nickel-base superalloy at a solutionizing temperature above a gamma-prime solvus temperature of the nickel-base superalloy, thereafter first quenching the nickel-base superalloy in a first molten salt bath maintained at a temperature of from the gamma-prime solvus temperature to about 100° F. below the gamma-prime solvus temperature, thereafter second quenching the nickel-base superalloy in a second molten salt bath maintained at a temperature below an aging temperature of the nickel-base superalloy, and thereafter precipitation heat treating the nickel-base superalloy at the aging temperature to precipitate an aged microstructure having gamma prime phase in a nickel-base matrix.