Contact morphology and constitutive equation in evaluating tensile properties of austenitic stainless steels through instrumented spherical indentation

Abstract

We evaluate representative stress and strain of austenitic stainless steels using instrumented indentation tests with a spherical indenter by taking into account the real contact depth and effective radius. We investigate the relation between material pileup underneath the spherical indenter and the strain-hardening exponent in uniaxial tensile tests for these steels. We evaluate the suitability of three constitutive equations, the Hollomon, Ludwigson, and Swift equations, for describing linear-type strain-hardening of austenitic stainless steels. Using the real contact depth and effective radii developed for the austenitic stainless steels, we find good agreement between representative stress and strain in instrumented indentation and uniaxial tensile tests.