The Study on Plastic Flow Behavior and Constitutive model of GCr15 Steel in Isothermal Compression

Abstract

The plastic deformation behavior of GCr15 steel under temperatures ranging from 700°C to 900°C and strain rates ranging from 0.01s-1 to 10s-1 was researched by isothermal hot compression testing. The strain stress curves obtained by tests show that the maximum stress decreases with the temperature while increases with the strain rate. In the beginning of plastic strain, the stress increases with the strain to maximum stress showing strain hardening, then decreases with strain showing strain softening. The flow behavior is modeled by a combination of exponential and linear functions with 3 parameters and the parameters were obtained by regressions. The effect of temperature and strain rate on the maximum stress was studied by an Arrhenius-type equation. The new constitutive model was verified in this paper.