Extensive modeling of high temperature deformation for cyclically softening material

Abstract

A unified inelastic constitutive equation is proposed to describe the cyclic inelastic deformation of 2 1 4 Cr-1Mo steel at an elevated temperature of 550°C. In the present study, the evolution of overstress is discussed which is shown to lead to a time-independent term in the inelastic strain rate. This term is proportional to the stress rate. Another significant point proposed in this study is the distinction of the inelastic deformation depending on the evolution of overstress. A mathematical model has been developed based on these assumptions. Many numerical experiments were conducted to examine the validity of the present model, and in comparison with the experimental results, the present model has been shown to give good descriptions for a wide variety of loading conditions, including rate-dependent plasticity, stress relaxation, and cyclic softening.