Patent ID: 6405601
Filing Date: 2002-06-18
Classification: G01N

Abstract:
A method of estimating the crack growth rate of an HIPed IN718 cast component in an air or steam environment comprising determining the average grain size diameter and duration of hold time at about 593Â° C. and solving the following equation, &dd;a&dd;N=1&AutoLeftMatch;1.19Ã—105Ã—GS+5.59Ã—104Ã—Env-1.17Ã—105Ã—GSÃ—Env+0.66Ã—HT-7.267Ã—GSÃ—HTwhereby N is the number of operating cycles, a is the crack length, da/dN is crack growth rate, GS is the average grain size in meters, HT is hold time in seconds, Env is 1 for an air environment, and Env is âˆ’1 if a steam environment.