Micromechanical modeling of the elastic-viscoplastic behavior of polycrystalline steels having different microstructures

A micromechanical model based on a new and non-conventional self-consistent formulation has been applied to describe the elastic-viscoplastic behavior of steels with different microstructures in a wide range of strain rates. Good agreement between experimental and model predictions is found concerning the behavior of a ferritic single-phase interstitial free steel (IF) during quasi-static and dynamic tensile loadings. Due to the introduction of key physical parameters in the mathematical model, a good description is obtained of the differences observed between the constitutive behaviors of IF, high-strength low alloy (HSLA) and dual-phase (DP450, DP500 and DP600) steels. These differences concern strength, strain hardening as well as strain rate sensitivity.