Patent ID: 11697857

Abstract:
A method of making a forged, martensitic, stainless steel alloy is provided. The alloy is a forged preform of martensitic, pitting corrosion resistant stainless steel alloy comprising, by weight: 12.0 to 16.0 percent chromium; greater than 16.0 to 20.0 percent cobalt, 6.0 to 8.0 percent molybdenum, 1.0 to 3.0 percent nickel, 0.02 to 0.04 percent carbon; and the balance iron and incidental impurities. The alloy has a microstructure that comprises a retained austenite phase less than or equal to 2 percent by volume of the microstructure. The method heats the preform to a solutionizing temperature to form a solutionized microstructure. The preform is cooled with a liquid to room temperature. The preform is immersed in a cryo-liquid to transform the retained austenite phase in the microstructure to martensite. The preform is heated to a temperature of less than 600° F. for a time sufficient to form a tempered forged preform.