Study On Springback Control Methods On The Process Of Forming Of HSS

With the escalating energy crisis and environmental problems, energy saving and safety have become very important issues for the automotive industry. Lightweight, high-performance in driving and collision safety of vehicles have become the main direction of competition of automobile enterprises. Because of the excellent energy absorption properties and specific strength properties can meet the lightweight and security requirements, High-strength steel and other high-strength plate have been more and more widely used in the automotive industry.As compared with ordinary steel plate, high strength steel have lower section shrinkage and higher yield strength, that reduce formability. Especially, the springback after the process of high-strength panels stamping have became major problem, or even a bottleneck in automobile manufacture.For controlling the springback of HSS in the covering mold development process in Chongqing Digidie Auto Body Co., Ltd., general springback and sidewall curl springback mechanism were analyzed, springback control methods was summarized, analyzed and validated the methods effectively, the results showed that the control methods are effective.Specific studies are as follows:1, The performance of HSS is summarized, general springback mechanism and sidewall curl springback mechanism are analyzed based on a large number of technical date at home and abroad for reference.2, Many key technologies, such as shell theory, constitutive equations, contact algorithm, thickness integration, cell size and division, etc. are summed up of numerical simulation methods. The optimized parameters are obtained combined with PAM-STAMP 2G actual Applications, and the rule of cell size type is fitted.3, Take the S-Rail from NUMISHEET'96 benchmarks for the analysis model, The influencing factors on springback——materials properties, punch radius, blank holder force, drawbead force and punching technical——are analyzed using PAM-STAMP 2G stamping simulation software, and results show that the punch radius are the main factors to side wall curl springback, and the drawbead forces are the main factors to normal springback through the orthogonal design of experiments.4, The general methods are found to control springback from the springback mechanisms, and that are proved efficiency through different examples. Based on analysis of the forming properties of HSS A-pillar, the whole process of mold development is completed, including the springback control, molds design and product testing analysis. And ultimately, qualified products are got.