超高强度钢G31的动态力学性能及断裂阈值

为了研究超高强度钢G31的动态力学性能,通过对G31钢进行动、静态力学性能实验,得到G31钢的动、静态力学性能,并由实验数据拟合得到了G31钢的本构方程。通过金相显微镜观察了实验前后试样的金相图。结果表明:在动态压缩条件下,G31的力学行为表现为变形初期的应变强化阶段和变形后期的温度软化阶段;在变形后期实验曲线与拟合本构方程曲线有较大差异。仿真对比分析结果证实,变形温升是造成该差异的主要原因。观察金相图发现,材料在较高应变率下发生绝热剪切断裂,并由相关理论计算得到了试件的绝热剪切断裂阈值范围。

Dynamic Mechanical Properties and Fracture Threshold of Ultra-high Strength Steel G31

In order to study the dynamic mechanical properties of ultra-high strength steel G31,the dynamic and static mechanical properties of G31 were obtained through the dynamic and static mechanical properties experiments of G31,and the constitutive equation of G31 was obtained by fitting the experimental data.The metallographic images of the samples before and after the experiment were observed by metallographic microscope.The results show that under the condition of dynamic compression,the mechanical behavior of G31 shows the strain strengthening stage in the early stage of deformation and the temperature softening stage in the late stage of deformation.The experimental curve in the late stage of deformation is quite different from the fitted constitutive equation curve.The simulation results show that the deformation temperature rise is the main reason for the difference.The results show that the adiabatic shear fracture occurs at high strain rate.The threshold range of adiabatic shear fracture was calculated by related theory.