Formability Evaluation And Numerical Simulation Of Cold-Rolled Automobile Sheet DP590

In recent years, automobile industry developed rapidly in china, the volume of which reached18.2647million in2010, ranking first in the world. In automobile, steel plate materials takes over about60%～70%of the whole weight. If the weight reduced10%, the fuel efficiency increased by6%～8%, so the utilization of high-strength steel which not only achieves the strength requirements but also meets the weight-limited requirements become the development tendency of automobile steel.In this paper, the effect of microstructure and texture on formability of cold-rolled dual-phase steel DP590was studied by contrasted with deep drawing steel DC01, DC03, DC04and DC06. And then, the formability of DP590steel was respectively evaluated from experimental and numerical simulation.The major research contents are as follows:1) Through optical microscope, SEM and TEM, the microstructure and morphology in DP590steel was observed; with EBSD, the texture of steel was measured; the mechanical properties and forming parameters of the steel was obtained by the uniaxial tensile test; and then the effect of microstructure and texture patterns on forming performance was studied.2) By using the laboratory BCS-50AR sheet universal testing machine, the basic forming test on DP590and DC steel which included hole-flanging test, conical-cupping test, cupping test was carried out. And the effect of blank holder force, punch speed, control load and other parameters on the forming performance of steels was analyzed. At the same time, the influence of the material itself on the expansion and the tensile properties of the flange was studied.3) Through the laboratory WDW-300electronic universal testing machine, the bending test on the DP590and DC06was carried out with different bending angle and bending radius, and then compare the spring-back angle and analyse the impacting factors.4) Through the ANSYS/Ls-dyna finite element analysis software to test the IE value of the steel during the forming process, analyze and simulate the influence of punch speed blank holder force on the IE value. Establish a kind of applications in thin steel forming performance of the numerical simulation algorithm 5) The forming limit diagram of DP590was established through steel die bulging test. By comparing the FLD0of DP590to other steels, the impacted parameter of forming limit diagram was analyzed, which Provided theoretical basis to the stamping process.