Microstructural Analysis and Micromechanical Modeling of Flow Behaviour of Dual Phase Steels Using a Representative Volume Element Method

Micromechanical modeling of flow curves of DP500 and DP600 steels in uniaxial tension was carried out using the representative volume element (RVE) method. Digimat and ABAQUS software were coupled and used to provide the required RVE model parameters and to perform simulations. Modeling results were validated using the experimental flow curves of the steels. It was found that the flow curve of DP500 steel was accurately predicted from the onset of plastic deformation up to the onset of necking. In case of DP600 steel, the numerical flow curve accurately predicted the experimental flow curve of steel after 0.07 strain up to necking strain. The RVE size of 12.7x12.7x12.7 mum and 7.9x7.9x7.9 mum containing 26 martensite islands were found as the optimum RVE sizes for DP500 and DP600 steel, respectively. A mesh of C3D4 elements having a size of 0.050 mum was found to be the optimum element type and mesh size.