High temperature low cycle fatigue life prediction method of nickel based alloy based on crystal plasticity theory

The high temperature tensile test and low cycle fatigue test of Inconel 718 nickel based alloy were carried out, and the fatigue crack initiation process of the alloy was analyzed by crystal plasticity finite element method. The results show that the initiation life of high temperature low cycle fatigue crack of Inconel 718 nickel based alloy decreased with the increase of total strain range. The high temperature low cycle fatigue cracks of the nickel based alloy were easy to initiate at the trigeminal grain boundaries, and there was a large cumulative plastic slip in these areas.