Research Of Experiment And Numerical Simulation Of Recrystallization Process Of B1500HS Boron Steel

In recent years, advanced high strength steels have been more and more widely applied in the automobile industry due to their many advantages. As in the normal temperature, the improvement of the strength of steel plate also means deformation resistance increased and forming difficulty. As a new production process, hot stamping can help to solve these problems. In the advanced high strength steel hot stamping process, the plate microstructure determines its mechanical properties and physical properties.Therefore,the research on the microstructure evolution in hot forming processes of high strength steel plays a key role in the production process optimization.This paper employs the boron steel produced by Baosteel-B1500HS as the object of the investigation.On the basic of quenching experiments, quantitative metallographic technique and microstructure simulation technology,the law of microstructure evolutions of recrystallization in the heating process and uniaxial hot quenching process.Through the quenching experiments, the effect of heating temperature and holding time on the microstructure and grain size were studied.Get the quantitative relation between the grain size of austenite and such process parameters.On the basis of the experimental data, B1500HS boron steel austenite transformation temperature was820-850℃,while austenite grain growth activation energy was Q=80.969kJ/mol, and get the austenitic grain size and relationship type, namely the austenite grain growth kinetic equation: Dm2-D02=1.439×105texp[-80969/(RT)]According to the recrystallization and grain growth process of Monte Carlo Potts model, a computer program is compiled to simulate grain growth and recrystallization evolution procedure in heating process of boron steel.This program realized grain microstructure evolution of visual simulation, and revealed the corresponding recrystallization microstructure evolution. The simulation results and the experimental results are compared, which is proved that the model can effectively simulate the boron steel during heating recrystallization processWith the help of finite element software Deform3D, we conducted the plate microstructure evolution under different strain,strain rate and temperature in the uniaxial hot strenching process. Strain, strain rate and temperature on the dynamic recrystallization microstructure evolution effect in the hot strenching process was investigated in this paper. The simulation results show that to reduce the deforming temperature, increase strain rate and degree of strain, the dynamic recrystallization grain refinement would be facilitated.