Research on Springback during Hot Stamping with Uniform and Local-Thickened Sheet Blanks

In this study, the effect of forming temperature, blank holder force, die entrance radius, die corner radius and blank local thickening on the springback of square cups were studied, by conducting finite element simulations of the hot stamping of 2024 aluminum alloy sheet blanks. Within the range of process parameters investigated in this study, increasing the forming temperature, blank holder force and die corner radius or decreasing the die entrance radius all lead to lower values of springback in hot stamped square cups after unloading. Compared to uniform blank, local-thickened sheet blank can significantly reduce the springback in hot stamped square cup. When the side length of the square-ring-shaped convex rib of the thickened blank is equal to the punch width and the convex rib faces downward, significant reductions in the springback, of at least 55.9%, can be achieved.