Characteristic Fatigue-Creep Interaction Behavior of an ESR-Cast-to-Shape Gas Turbine Disc Alloy with Coarse Branch Crystals at High Temperature

摘要

The fatigue-creep cycling life and crack propagation rate of a Fe-Ni-Cr alloy were obtained from a series of tests. The results show different dependence of the fatigue-creep interaction on the stress composition. Overlapping of alternative stress with mean stress at high temperature could cause fairly strong fatigue creep interaction and reduced fracture life, as compared with both pure fatigue and pure creep tests. The high temperature fatigue creep crack propagation rate, as a function of the stress intensity factor range (DELTA K), could also be described by the Paris equation with varied exponent (m).