A Study Of Eletroplastic Stress Relaxtion And Eletroplastic Bending Properties Of DP980High Strength Steel

Lightweight automobile has become the research focus of vehicle andraw material industry all over the world. The most effective method isadopting high strength steel instead of traditional steel in bodywork.DP980is a1000MPa level advanced high strength steel which has highstrength, forming force and serious springback.Electroplastic effect refers to the phenomenon that when the materialwas under the function of the current, the deformation resistance decreased,plasticity increased. Research showed that, the current could also producegrain refinement, delay the martensitic transformation, repair materialdamage. Therefore, applying electroplastic effect to improving the formingperformance of advanced high strength steel, eliminating springback,improving the service life of the die, has very good application prospect.In this paper, preliminary experimental study was carried on to studyapplying electroplastic effect to advanced high strength steel stamping.Theconcrete work includes:1．Gave a brief introduction of DP980’s properties as therepresentative of dual phase steel, summarized the research work onimproving the metal properties with current, which showed the feasibilityof electroplastic effect applying electroplastic effect to improve theformability of advanced high strength steel.2．Designed electroplastic tensile experiment, researched the tensileproperties of DP980under the action of impulse current, and the traditionaltensile results are compared, analyzed the effect of pulse current on thetensile properties of DP980, summarized the influence of electrical parameters on the tensile properties of DP980.3．Designed the electroplastic stress relaxation experiments, did theresearch of DP980’s stress relaxation behavior under pulse current stress,and compared with the experimental results without electricity, analyzedthe effects of the current pulse on DP980’s stress relaxation behavior,summarized the influence of electrical parameters on the DP980’s stressrelaxation.Experimental analysis was carried out on the thermal effects inthe process of experiment, the experimental results were added.4．Designed the electroplastic V-bending experiments. Maderesearch on bending springback and bending force of DP980under pulsecurrent. Compared to the cold bending experiment andbending-electroplastic relaxation experiment. Analyzed the effect of pulsecurrent for bending springback and bending force of DP980, the influenceof electrical parameters was summarized.