Deep drawing behavior of twinning-induced plasticity-cored three-layer steel sheet

Herein, we report the results of our experimental and computational investigation of the deep drawing behavior of twinning-induced plasticity (TWIP)-cored three-layer steel sheet. Various directional tensile tests for monolayer sheets of the TWIP and low-carbon (LC) steels were performed for evaluation of flow curves and anisotropic coefficients, which are used as input data of the finite element analyses for deep drawing of the monolayer and three-layer sheets. The experimental deep drawing behaviors of the layered sheets of three thickness ratios, and of the monolayer sheets, are computationally analyzed in terms of earring and variations of local thickness along the positions in the drawn cups. It was found that the three-layer sheets are more planar-isotropic in the sense of earring than the monolayer sheets, even more than the TWIP steel sheet. The thickness uniformity along the initial radial direction in the layered sheets is in between the heterogeneous TWIP steel and the relatively homogeneous LC steel. The present results shed light on the future direction of development of steel sheets with planar-isotropic and homogeneous deep-drawing characteristics.