板条状马氏体的亚结构及形成机制  

Substructure and formation mechanism of lath martensite

作　　者：刘宗昌[1] 计云萍[1] 段宝玉[1] 任慧平[1] 

机构地区：[1]内蒙古科技大学材料与冶金学院,内蒙古包头014010

出　　处：《材料热处理学报》2011年第3期56-61,共6页Transactions of Materials and Heat Treatment

摘　　要：研究马氏体亚结构及形成机制具有重要理论意义和应用价值。应用35CrMo等材料,淬火为马氏体组织,采用JEM-2100电镜观察马氏体形貌和亚结构,发现35CrMo钢马氏体为板条状,亚结构除了高密度缠结位错外,还有高密度层错。结合2Cr13、Fe-15Ni-0.6C合金试样的浮凸试验,应用隧道扫描显微镜观察表面马氏体浮雕形貌,测定浮凸的微细尺寸。综合上述试验结果,分析位错、层错形成机制。发现浮凸效应中没有出现位错滑移迹象,认为切变模型不能解释高密度位错和层错的形成。最后应用马氏体相变新机制分析了高密度缠结位错、精细层错的形成。Morphology and substructure of martensite in 35CrMo steel were studied by JEM-2100 transmission electron microscope.Lath martensite is observed in 35CrMo steel and the substructure is composed of high density dislocation tangle and high density stacking fault.The morphology of martensite surface relief in 2Cr13 steel and Fe-15Ni-0.6C alloy was observed and the size of the surface reliefs was measured by scanning tunneling microscopy.Based on the experiments,the formation mechanism of dislocation and stacking fault was analyzed.The results show that no dislocation slipping is observed for the surface relief.It is considered that the shear transformation model can not explain the formation of the high density dislocation and the stacking fault.A mechanism of martensite transformation is proposed to explain the formation of the high density dislocation and the fine stacking fault in lath martensite.

关 键 词：板条状马氏体 切变 表面浮凸 位错 层错 

分 类 号：TG156.3[金属学及工艺—热处理]