Regular Article

Investigation of process parameters and plate local thickening on residual stresses in hot stamping process

¹ School of Mechanical and Electrical Engineering, Xinyu University, Xinyu 338004, PR China
² State Key Laboratory of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, PR China
³ Xinyu Engineering Technology Research Center of 3D printing manufacturing and Application, Xinyu 338004, PR China
⁴ School of Materials Science and Engineering, Hubei University of Automotive Technology, Shiyan 442002, PR China

^* e-mail: lijinboxyxy@126.com

Received: 6 January 2021
Accepted: 12 February 2020

Abstract

In this paper, local-thickened plates are adopted for aluminum alloy square cups stamping with relatively low values of residual stresses and small radius at the bottom corner. By utilizing numerical and experimental methods, the effects of process parameters and plate local thickening on the residual stress distribution of hot stamped aluminum alloy square cups are studied. Furthermore, the influence of plate local thickening on the radius of bottom corner of square cups is also investigated. The results showed that with an increase in the forming temperature, blank holder force and die corner radius, residual stresses in hot stamped square cups can be reduced. The same effect can be achieved by decreasing the die entrance radius. As opposed to the flat plates, using local-thickened plates can not only reduce the residual stresses values in hot stamped square cups, but also decrease the radius at the bottom corner of square cups. When the optimized thickening scheme of plate is used, the smaller radius at the bottom corner, the lower residual stresses in the square cups are obtained.