Surface Crack Propagation in Plate Specimens of 1Cr-1Mo-1/4V Turbine Rotor Steel under Creep-fatigue Condition

Abstract

It is important to know the crack propagation behavior under creep-fatigue condition in order to insure the security of high temperature components. In this study, crack propagation tests were conducted using two sizes of plate specimens of a 1Cr-1Mo-1/4V forged steel with a through or surface crack at 550°C. Regardless of the specimen size and crack shape, the crack propagation rate was correlated well with creep J-integral range, whereas it was not with elastic stress intensity factor nor net section stress. A numerical simulation method was successfully developed for the surface crack propagation on the basis of the relationship between crack propagation rate and creep J-integral range.