Influence of Prestraining and Deformation Rate on Viscoplasticity and Strain Ageing of Metal Materials. Stress-Controlled Loading and Creep of SCM435 Steel under Uniaxial Loading.

Based on experimental data using SCM435 steel obtained by us, it was found that flow stress and relaxation properties of metallic materials depend on both viscoplasticity, which responds quickly to strain rate change, and strain ageing, which responds slowly. In this study, both flow stress under nominal stress-controlled tensile loading in which strain rate increases gradually, and creep properties which show a gradual decrease in strain rate, are investigated experimentally and theoretically. It is shown that the viscoplastic constitutive model proposed by us, which takes the time dependence of strain ageing into consideration, has good applicability in describing stress-controlled inelastic behavior, including the creep property.