High Temperature Crack Propagation and fractre of superalloys

摘要

High temperature crack propagation and fracture behavior of 6 china produced disk superalloys has been studied. Crack propagation rates wre determinedat 650 degree creep, fatigue and creep/fatigue interaction conditions. THe crack propagatin rate is raised with the increasing o strength of superalloy and is also increased with the dwelling time at maximum stress level of cyclic creep test condition. Crack propagation behavior is very deendent on high temperature time dependent ductility. Ductility improvement can increase crack propagation resistance by means of the softening heat treatment, grain boundary precipitates control nad microalloying treatment