Characterization of deformation behavior for waspaloy under creep-fatigue interaction

Abstract

Hysteresis loops of strain controlled LCF tests for Waspaloy were characterized within the temperature range of 350°C and 600°C. Materials deformation behaviors under symmetric and asymmetric loading conditions were assessed using Chaboche’s viscoplasticity model. The strain hardening and stress relaxation occurring in the loading cycles were estimated. Hardening plays an important role at an early stage of loading, but the stress relaxation becomes dominant at a later stage. The observed change in the slope of hysteresis loops between the first cycle and the second cycle and mean stress relaxation under asymmetric loading conditions may be explained by the evolution of the kinematic hardening variable which depends on the inelastic strain range. The effect of creep on the cyclic shake down is expected to be limited.