Investigating the effect of the interface in numerical calculation of mechanical behavior of dual phase steels by using micromechanical modeling cells

Dual phase (DP) steels have a fine microstructure consisted of martensite islands, dispersed in a ferrite matrix. Due to high strength along with high work hardening rate and ductility, this group of steels has received an extreme attention. In the present work, the effect of presence of the interface between ferrite and martensite in numerical simulation of the mechanical behavior of dual phase steels such as yield stress and tensile strength is studied. As the first step, dual phase steels with different volume fractions of martensite (Vm) are produced by various heat treatment procedures on low carbon steel and tensile tests are conducted on the produced specimens in order to determine their mechanical behavior. As the second step, a numerical investigation, based on a micromechanical model, is developed to capture the mechanical behavior of DP steels. ABAQUS finite element package is used in the numerical simulations. This investigation has considered the presence of constituting phase interface by taking advantage of Cohesive Zone Elements in the finite element software. In the numerical simulations, each phase has considered as an elastic-plastic solid. The obtained results show that the interface has a significant effect on the tensile behavior of DP steels and there is a good agreement between cohesive model and the experimental data.