Constitutive Modeling of Anisothermal Cyclic Plasticity of 304 Stainless Steel

Temperature-history dependence in anisothermal cyclic plasticity of 304 stainless steel is studied for the constitutive modeling within the temperature range from room temperature to 600°C. Cyclic plastic behavior under in-phase and out-of-phase changes of temperature and athermal strain is analyzed first by use of an elaborate constitutive model with its material constants determined from isothermal experiments; good agreement is obtained between the predictions and experiments, if we assume that the internal change proper to higher temperature prevails under such thermomechanical cycling. This finding leads us to extend the evolution equation of isotropic hardening so that it can be valid for more complex variations of temperature. The extended model simulates well the recent experiments of Niitsu and Ikegami under multi-step changes of temperature.