Simulation of orientation gradients in a ferrite matrix containing hard martensite under plane-strain flange deformation

The plastic deformation behavior of dual phase (DP) steel under plane-strain flange deformation during a cup deep-drawing process was simulated using a crystal plasticity finite element method (CPFEM). The representative volume elements of a simple geometry were used to capture the in-grain orientation gradients of a ferrite matrix containing a hard martensite particle. The divergence of the reorientation rate vector and the stability parameter were used to determine relatively stable, metastable and unstable orientations for the ferrite matrix. The simulation showed that both the formation of the in-grain orientation gradients and the inhomogeneity of the local average misorientation (LAM) distribution were enhanced by the hard martensite particle. The analysis showed that the orientation gradients for the ferrite phase within the DP were simultaneously influenced by both the initial orientation and the martensite. The relative contribution of the two factors was strongly dependent on the stability of the initial orientation under the plane-strain flange deformation.