Predicting the deformation behavior of dual phase steels using micromechanical modeling of cells

In the present work, the deformation behavior of dual phase (DP) steels, composed of martensite and ferrite phases, is investigated by means of experimental data and micromechanical modeling. As the first step, dual phase steels with different volume fractions of martensite (Vm) are produced by various heat treatment temperature 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 with using cohesive zone model, is developed to capture the mechanical behavior of DP steels. ABAQUS finite element package is used in the numerical simulations, in which each phase has been considered as an elastic-plastic solid. The accuracy of the developed model is investigated by comparing the numerical and experimental results. The model is then used to investigate the effect of small to large particle size ratio of martensite (R=b/a) and the volume fraction of martensite on the deformation behavior of the DP steel. The acquired results show that yield stress and UTS is increased when the volume fraction of the martensite phase is increases in constant R. This study shows that considering the interface of the constituting phases greatly affects the numerical results and produces more realistic results. The numerical results in which the effect of the presence of the interface is considered, can closely predict the experimental data.

Keywords:

Dual phase steel , Micromechanical modeling , Elastic-plastic , Cohesive zone model