Numerical modelling of stress‐strain response and deformation‐induced martensite in metastable austenitic stainless steels under monotonic tensile loading

Abstract

AbstractA constitutive model describing the deformation‐induced martensite transformation in metastable austenitic CrNi steels is presented. In line with the previous work of Stringfellow et al. [1], the material is considered to have a composite response of the underlying austenite and the evolving martensite phases. The stresses and strains in the individual phases are described using viscoplastic models. The effective properties of the material are then computed by a homogenization method. Strain hardening in the individual phases is represented using separate flow rules. Furthermore, based on the plastic strain in the austenitic phase, a transformation kinetics model describes the evolution of the martensite volume, in the two‐phase composite.A numerical implementation of the model is done in the finite element program FEAP [2]. The parameters in model are identified by experimental data using the least‐squares optimization. Finally, some results are presented using an illustrative boundary value problem of a structured surface.