Finite element simulation and experimental investigations of cold stamping forming defect of A588-A thick weathering steel bogie lower cover

Abstract

In order to improve the stamping accuracy of the bogie cover plate of the rail vehicles. The cold stamping forming process of A588-A thick weathering steel plate with variable initial bending size (“H”) produced by the pre-straightening process was investigated by numerical simulation and experiment. The effects of “H”, curvature direction of the plate, and small curved fillets radius on the forming quality of the thick steel plate were analyzed. The results demonstrated that there are defects, such as serious springback, distortion of stamping fillet, and low profile accuracy. We propose some corresponding defect control methods. The larger initial bending size “H”, the higher springback value occurred. By applying 1.2–1.4 times springback compensation to the die geometry, the springback was reduced and the contour accuracy was enhanced exponentially. By replacing the original die fillet material with C12MoV and reducing the die clearance, the cross-section distortion of the stamping fillets due to bad die fittingness could be eliminated. The accuracy of the component can also be improved by controlling the curvature direction of the plate. The cold stamping test was carried out by using the best process parameters and defect control methods. The results show that the control methods are extremely effective.