Research Of Forming Properties Of High Strength Sttel For Veehicle Body Under Biaxial Tensile Prestrain And High Speed Forming

Environmental protection, safety and energy efficiency are the three majorproblems in the automotive industry. With a further increase in the automotiveindustry development and the pressure on the environment, environment and energyissues are becoming the important problems in automotive industry especially inrecent years. With the application of high strength steel, automotive light weightingcan effectively reduce vehicle weight and improve safety. However, high yieldstrength and tensile strength of the high-strength steel make it more easily to ruptureand rebound than regular steel and the stability of the part size and shapedeteriorates. Therefore, the research and development processing of advanced highstrength steel sheets for automotive body are currently key issues to enhancing itsformability and expanded its scope of application.Electromagnetic forming is one kind of high velocity forming, which releaseenergy in a short time and make the metal forming with impulse impact pressure.Compared to the other high velocity forming electromagnetic forming can improvethe formability of the metal, it is of great significance in the research of process foradvanced high strength steel. What’s more, the combination of high strain rateforming and general processing technique demonstrate its technical advantagesbetter, and it is more valuable in applications.In this paper, the research objects are dual-phase steel DP590and B280VK.the stamping forming parameters of the materials were obtained by the quasi-statictensile experiments and cupping test.The influence of biaxial tensile prestrain for two kinds of AHSS under electro-magnetic high strain rate bulging, stretching to the formability and the microstructu-re were investigated by the combination of biaxial tensile pre-strain and electromagnetic forming. The pre-strain have a significant impact on the formability of the sheet.n the experiment of electromagnetic high-speed stretch, the pre-strain with the samedirection with high-speed tensile increases forming limit of The final deformation,but the Vertical pre-strain reduces it. the ferrite is shaped by pre-strain and thedistribution of marten site also changed, then the formability of the materialchanged.The applications of the combinative process of biaxial tensile pre-strain andelectromagnetic forming for advanced high strength steel were discussed.