The effect of crystallographic orientation on the micromechanical deformation and failure behaviors of DP980 steel during uniaxial tension

Abstract

The effect of crystallographic orientation on the deformation and failure behaviors of DP980 steel was investigated using the crystal plasticity finite element method (CPFEM). A phase identification method that was based on the image quality of EBSD data and a filtering process provided the individual crystallographic orientations for ferrite and martensite phases in DP980 steel. By using a technique for the direct mapping of filtered microstructure into finite element meshes, CPFEM can capture the heterogeneity of strain–stress partitioning and the effect of microstructure heterogeneity on the hot spots for void formation in DP980 steel during uniaxial tension. The failure mechanisms were studied through scanning electron microscope (SEM) observations of the polished sections of a failed tensile specimen. An isotropic elasto–plastic FEM was used to simulate the heterogeneity of strain–stress partitioning and the failure behaviors of DP980 steel without considering the crystallographic orientation of the constituent phases. The simulation results demonstrated that the initial crystallographic orientation of the constituent phases significantly affects the heterogeneity of strain–stress partitioning and the hot spots for void formation in DP980 steel during uniaxial tension.