Compressive Flow Stress Characteristics of Carbon Steels and Stainless Steels during Cold Forging

Abstract

Flow stress-strain curves of material are necessary in numerical analysis, such as finite element analysis, of cold forging process. The behaviors of compressive flow stress-strain in carbon steels and stainless steels at various temperature in the range of cold forming are studied by static and dynamic upsetting tests. In the experiments, the stress-strain of feritic stainless steel shows similar curves with that of carbon steel in the temperature range from 30 to 200°C. Work-hardening behavior of austenitic stainless steel is more significantly affected by deformation temperature than those of carbon and feritic stainless. From the results of experiments, the flow stress is formularized as a function of strain, strain rate and temperature. The validity of this equation is examined through the comparison between load measured in upsetting test and that obtained by numerical simulation.