Microstructure-Based Modelling of Elastoplastic Properties and Deformation Characteristics of Advanced High Strength Dual-Phase Steel

The 3D representative volume element modelling concerning different microstructural features and renowned work hardening models was developed in this study. Simulation results of stress–strain relationship based on the Kocks–Mecking model exhibit satisfactory accordance with the experimental results compared to the Swift–Voce law and J₂ elastoplastic-based theory. The volume fraction of martensite has a great influence on the mechanical properties of the DP1180 steel. The results indicate that the plastic stress is mainly condensed in martensites and phase boundaries, while the plastic strain localisation is predominantly detected in the ferrite grains and/or between two narrow martensites. To capture the stress–strain partitioning behaviour and deformation particularities in DP1180, a further analysis based on evolving microstructure has been carried out on various strain levels after tensile loading. It offers insights into the role of each constituent phase on the mechanical properties as well as the dominant shear failure modes of the DP1180.