关键词: Wilshire方法, 各向异性, 蠕变, 镍基高温合金, 热强综合参数

Abstract: The important basis for the strength evaluation of aero-engine hot-end components is a simple and robust creep and stress rupture life prediction method with clear physical basis. For aero-engines nickel-based superalloys, the prediction accuracy of Wilshire method for creep properties under wide temperature/stress conditions is firstly discussed, then it is proved that the equivalent creep activation energy in this method system is closer to the lattice expansion activation energy than the traditional method, and the predicted stress cut-off points are closely related to the creep deformation mechanism of the alloy under different temperature/stress conditions. Secondly, the Wilshire method and the traditional Larson-Miller method were modified by introducing the crystal direction function related to tensile strength. The results show that the modified method can successfully predict the downward creep durability of different crystals with high accuracy. Finally, based on the Wilshire method, a thermal strength synthesis parameter based on the normalized stress is proposed. The composite thermal strength parameter can be used to evaluate the creep endurance of superalloy materials under normalized stress conditions. At the same time, based on the composite thermal strength parameter, it is beneficial to exert the potential of the high temperature performance of the material.

Key words: Wilshire equations, anisotropic, creep, nickel-based superalloy, comprehensive thermal strength parameters