高强38CrSi钢力学性能测试及本构关系研究

The quasi-static and dynamic mechanical behaviors of high strength 38CrSi steel with medium temperature tempering after quenching were investigated using a universal testing machine and a split Hopkinson tension bar (SHTB) for doing the Taylor impact test. The temperature range from room temperature to 700 °C was involved. The Johnson-Cook (J-C) constitutive relation with a slight modification on the temperature softening item was proposed to fit the test results. The modified parameters of the J-C constitutive model and Cockroft-Latham (C-L) fracture criterion were identified by fitting the experimental data, based on the combination of the numerical simulation results of Taylor impact test and the conditions of mushrooming and cracking. The parameters were validated by comparising the deformation and fracture results by the Taylor tests and the simulations with higher impact velocity. The consistency between experimental observations and numerical simulations indicates that the models and parameters obtained are competent to describe the dynamic large deformations and fracture behaviors of high strength 38CrSi steel.