马氏体相变不是“不变平面应变”  

Martensite Phase Transformation Not Invariable Plane Strain

作　　者：刘宗昌[1] 计云萍[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：《热处理》2013年第3期19-23,共5页Heat Treatment

基　　金：内蒙古自治区科技引导计划项目(20071911)

摘　　要：对Fe-15Ni-0.6C合金试样进行真空加热淬火,制取表面浮凸;采用扫描电镜和扫描隧道显微镜观察试样表面的浮凸形貌和划痕的变化。结果表明,在形成马氏体后,表面直线划痕变为曲线,间断、不连续或近似直线等形态。表面浮凸不呈N型而是帐篷形(∧),说明表面浮凸是马氏体转变时体积膨胀、不均匀应变的结果。马氏体相变不是切变,也非均匀应变。材料表面马氏体与材料内部马氏体在相变条件、形貌、晶体学特征等方面均有所区别。表面马氏体的表征不能作为研究材料内部马氏体相变的依据。总之,马氏体相变不是"不变平面应变"。It is very important to study the crystallography of martensite phase transformation. The Fe-15Ni-0.6C alloy specimens were vacuum heated and then quenched to obtain the martensite surface relief. The morphology of the surface relief and the change of the scratch marks on the surface of the specimen were observed by scanning electron microscope and scanning tunneling microscope. The results show that the straight-line scratch marks change to the curve or discontinuous type or basically maintain the straight line after the formation of surface martensite. The surface relief is not N-shaped but tent-like （ A ）. It is illustrated that the surface relief results from the volume expansion and the heterogeneous strain during martensite phase transformation. Martensite phase transformation is neither shear nor homogeneous strain. There are differences in the phase transformation condition, the mierostructure, the crystallography and other aspects between surface martensite and martensite in material interior. The characterization of the surface martensite can not he served as the basis of research on martensite phase transformation of the material interior. So martensite phase transformation is not invariable plane strain.

关 键 词：马氏体相变 切变 表面浮凸 不变平面应变 比体积 

分 类 号：TG111.5[金属学及工艺—物理冶金]