Creep Property and Creep Behavior of GH3536 Alloy

High temperature creep tests were carried out on GH3536 alloy under different stress levels at 815-900℃. Creep curves were drawn and the effects of test temperatures and test stress levels on creep properties of GH3536 alloy were discussed. The stress exponent and the parameters of Monkan-Grant relation of steady creep rate were obtained by least squares fitting. Extrapolation formula was established by L-M parameter method and creep fracture strength of GH3536 alloy was extrapolated. The results show that the creep mechanism of GH3536 alloy at high temperature was mainly dislocation slip and climb at the test temperatures and test stress levels. During creep process, the second phase precipitated. R type and W type cracks were formed at the grain boundaries and the second phase particles. Creep fracture was a ductile fracture caused by necking, and microvoid aggregation and growth occurred during the fracture process. According to the extrapolation formula, creep fracture strength of GH3536 alloy was 58 MPa for creep fracture time of 2 000 h at 815℃.