Microstructural deformation pattern and mechanical behavior analyses of DP600 dual phase steel

Abstract

Deformation pattern is the most important issue which can be effective on the prediction of mechanical behavior of dual phase steel in microscale. In this paper, simulation with large and small deformation theories using the real microstructure is employed to investigate the deformation pattern in microstructure of DP600 dual phase steel. Deformation pattern is mostly effective on the transition of rotation and displacement between ferrite and martensite phases and stress–strain behavior. Different deformation theories affect the predicted stress–strain behavior of dual phase steel using the finite element method. The obtained results from both numerical and experimental methods are used to investigate the effect of deformation in the microstructure. The performed experiments were interrupted in three stages to obtain the deformation pattern of components microstructure: necking initiation, localization and failure. Metallographic and SEM images were prepared to study the ferrite matrix and martensite grains deformation, and failure pattern in the microscale. Localization which causes severe deformation, rotation and displacement of the microstructure is defined as the failure criteria and the main source of void formation and rupture phenomenon. The predicted results such as stress–strain behavior and deformation pattern using small and large deformation theories are compared with the experimental findings and observable voids in the SEM images.