Island-matrix inhomogeneous deformation behavior, formation of deformation band and BUT forming of DP steel

Islands-Matrix-Dual-phase (I-M-DP) steel is received a great deal attention for better concern with the emissivity, fuel consumption and passengers safety. A number of deformation plasticity issues are yet to be fully understood. Complex deformation stages for various stain is predicted as the natural outfall of the plastic strain localization caused by the ill-assorted deformation between the martensite-island phase and the ferritic-matrix phase. Modeling is carried out both in macro level by bending under tension (BUT) for different roller radius/sheet thickness ratios to acquire strain and stress state deformation and micro scale by Representative Volume Element (RVE) according to element position. It can relate both the 2D, 3D micro and macro scale finite element based BUT model’s result of flow behavior. Systematically strain based severe deformation pattern arises from outfall of plastic strain localization and von Mises stress distribution in island-matrix steels are investigated on the microstructure by finite element method for ill-assorted deformation between phases.