Integrated crystal plasticity and phase field model for prediction of recrystallization texture and anisotropic mechanical properties of cold-rolled ultra-low carbon steels

摘要

A multi-scale approach integrating a polycrystal plasticity finite element (CPFEM) and a multiphase field model (PFM) is developed in this study and employed to the prediction of anisotropic mechanical properties of annealed ultra-low carbon steel. The CPFEM simulates inhomogeneous local deformation and orientation distribution of ultra-low carbon steel, while the PFM predicts microstructure evolution originating from nucleation and growth. The present study highlights a systematic modeling process including reduction of the stored energy by the recovery process, nucleation of grains with preferred orientation based on generalized strain energy release maximization theory (GSERM), and grain growth with consideration of the stored energy difference and misorientation between neighboring grains, which are provided from local effects in the CPFEM. The two computational approaches are numerically mapped by the Wigner-Seitz cell method to efficiently transfer state variables between the domains of finite element and finite difference schemes for CPFEM and PFM, respectively. The proposed multiscale model is quantitatively validated through experimentally measured microstructural characteristics of annealed ultra-low carbon steel after the rolling deformation, i.e., its recrystallization texture in the aspect of pole figures and ODF, grain size, and distributions. Finally, the predicted microstructural information after the thermo-mechanical process is used as input for virtual mechanical tests simulating orientation-dependent tensile properties. The comparison of predicted orientation-dependent yield stresses and Lankford coefficients as measures for anisotropic mechanical properties with those of experiments confirm the validity and accuracy of the proposed CPFEM-PFM approach as an efficient tool for understanding the relationship between the thermo-mechanical process, microstructure, and mechanical properties in the material design stage.