材料期刊网

采用分离式Hopkinson压杆技术分析了TWIP钢在冲击载荷下应变速率对其性能的影响，采用金相（OM）、X射线衍射（XRD）、透射电镜（TEM）等方法对其变形前后的显微组织进行了研究。结果表明：高应变速率下，TWIP钢的应力-应变曲线存在响应时间，并且在中间阶段出现了波浪形的应力起伏。TWIP钢变形前后都是奥氏体单相组织，形变孪晶与静态变形条件下的相比，较易于多个孪晶系生成，孪晶的宽度、数量增加，间距减小。孪晶与位错的交互作用、孪晶与孪晶的相互作用、特别是多次孪晶的出现是使TWIP钢得到强化的主要变形机制。

The dynamic tensile test of TWIP steels was carried out by the technology of split Hopkinson compression bar at various high strain rates, the microstructure evolution of the specimen was investigated by optical microscopy(OM), X-ray diffraction(XRD), and transmission electron microscope(TEM). The results showed that, under dynamic condition, the respond time and stress fluctuating appeared on the stress-strain curves, there was single austenitic phase before and after deformed prossess. The amount and density of the twins during dynamic deformation were higher than that of the static deformation, besides, two or more twin systems were activated in most grains. The twin-twin interaction, the twin-dislocation interaction, especially more twin systems played an important role during dynamic deformation.