Quantitative Analysis of Strength and Plasticity of a 304 Stainless Steel Based on the Stress-strain Curve

A constitutive model including the kinetics of twinning and martensitic transformation has been established based on the dislocation theory and the mixture law. The stress-strain curve of a 304 stainless steel has been measured by a tensile test. The material constants for the constitutive model are then found through an inverse analysis of the stress-strain curve measured experimentally, determining the stress-strain relationship equation and the kinetics of twinning and martensitic transformation of the investigated alloy. The volume fractions of martensitic transformation have been measured by the magnetic tester of Fischer Model MP3C. It has been shown that the calculated stress-strain curve and the volume fractions of martensitic transformation are in agreement with those obtained from experimental measurements, demonstrating that the material constants found by using the stress-strain curve can capture the underlying materials science of deformation. On this basis, the influence of twins, martensitic transformation, and mechanical behavior of austenite and martensite on the strength and plasticity of the 304 stainless steel has been discussed further.