回火温度对高碳硅锰钢动态力学性能的影响

Microstructure of a high carbon silicon manganese steel quenched at 820 °C with oil cooling and then tempered at different temperatures was investigated, and the mechanical behaviour under high strain rates and various stress states was systematically examined by using the Hopkinson device. The results reveal that the quantity and size of carbides increase with the increase of tempering temperature. Speeifically, as the tempering temperature rises from 580 °C to 620 ^, the dynamic tensile (strain rate of 1400 s~) and compressive (strain rate of 3200 s~) strengths of the tested steel exhibit a deereasing trend, while an enhancement in dynamic tensile plasticity is observed. The Mises stress concentration in carbide and the shearing stress concentration at the micron carbide/matrix interface are crucial factors for microvoid nucleation during dynamic tensile tests of the tested steels. During dynamic compression, the plastic deformation of the steel is influenced by a coupling mechanism involving strain hardening and heat softening, thereby exhibiting significant strain rate sensitivity.