M_2钢冷变形时微裂纹形核原位观察与机理

In-Situ Observation and Mechanism of the Nucleation of Microcracks in M2 Steel during Cold Forming

采用带拉伸机构的扫描电镜和透射电镜等实验手段研究了热轧退火状态Ｍ２高速工具钢在单向拉伸变形时微裂纹形核机制及位错塞积状态。连续观察到了单向拉伸变形时钢中碳化物粒子的开裂全过程。证实了位错塞积的存在及其对微裂纹形核的促进作用。

SEM and TEM equiped with a tensile tester were used to investigate the nucleation of microcracks and dislocation pile up of the hot rolled M2 steel experiencing uniaxial extension and cold drawing deformation.Splitting of carbide particles in thesteel were observed continuously. This verifies the existence of dislocation pile-up and its stimulation to the nucleation of microcracks.