中文摘要：

采用Hopkinson压杆冲击加载装置和帽形试样对锻造态电磁纯铁DT4进行了应变率为10^3 s^-1的冲击压缩试验,利用光学显微镜（OM）、扫描电镜（SEM）和透射电镜（TEM）观察分析了高速冲击后的电磁纯铁的组织。结果表明,电磁纯铁中的剪切带（ASB）由变形带组成,剪切带内位错密度很低,基体中含有高密度位错。剪切带内没有发生相变。

英文摘要：

Microstructure evolution of shear bands originated from high strain ,high strain rate deformation in electromagnetic pure iron DT4 had been examined. Tests were performed on a specially designed stepped specimen by Hopkinson bar. Mictrostructure characteristic of shear bands was analyzed using optical microscope as well as scanning and transmission electron microscope. The results show that no evidence of transformation can be found within the shear bands. Shear bands exhibit some orientation. In addition, the dislocation density is lower in the ASB than that in adjacent matrix.