Study On The Microstructures And Properties Of Cold Rolled DP590and Its Application To Automotive Covering Panel

High strength steel is the main development trend of the automobilesteel, the use of advanced high strength steel represents the future direction ofdevelopment of automobile lightweight materials. DP590steel has some goodcharacteristics, such as high strength, low yield ratio, high initial work hardening rate,good ductility, etc. It is a new type of stamping steel. At present，some automobileenterprises apply it to the panel. In order to make the DP590steel is more widely usedin the field of automobile manufacturing, this paper studies are as follows:(1) Taking the cold rolled DP590plate as the object of research, this paperanalysis the microstructures and Mechanical properties of DP590automobile plateafter heat treatment.(2) By the cupping experiment of DP590automobile sheet after continuousannealing process, the influence of stamping parameters on the stamping results wasanalyzed, and it provides guidance for the setting of technological parameters in thefollowing simulation.(3) In this paper, the drawing forming process of the automotive B-pillar wasstudied by numerical simulation, using the finite element simulation softwareAUTOFORM. Combined with the bottom rupture and middle wrinkle of automotiveB-pillar, the main reason of B-pillar fracture, wrinkle defects in stamping process isstudied. And these defects are eliminated by adjusting the parameters in AUTOFORMsimulation. It provides guidance for accurate evaluation of forming properties andselection of suitable forming process of DP590steel.(4) AUTOFORM simulation of stamping forming processes of automobileA-column reinforced plate was studied by using the performance parameters ofDP590. The variation of the automobile A-column reinforced plate forming property wasanalyzed by adjusting the drawbead, blank holder force, feed angle, friction coefficient and otherparameters. The result shows that: the influence of the drawbead on formingperformance is the maximum. Therefore, adjusting the process parameters reasonablycan improve the forming performance, finally, can ensure the stamping formability ofhigh strength steel DP590and improve the using range of this steel.