【摘要】 用透射电子显微镜金属薄膜方法观察了35 CrNi 3 MoV、4 Cr 10 Si 2 Mo及碳钢的淬火和回火组织特征。发现,钢自高温淬火后得到的淬火亚结构对钢的回火组织和回火时析出的碳化物形貌、分布状态及位向关系有明显的影响。在淬火孪晶亚结构区域内,回火组织中的碳化物大都呈条片状,沿内挛晶边界成直排分布。电子衍射证明,这种碳化物主要是与基体之间成共格位向关系的M₃C,这时的组织类似于片状珠光体;在淬火位错亚结构区域内,回火组织中碳化物主要是颗粒状,大都沿原位错亚结构单元呈无规则状态分布。电子衍射证明,这种碳化物大都也是M₃C,但它们与基体之间主要成非共格位向关系,这时的组织应属于粒状索氏体。更多还原

【Abstract】 The characteristic structures of quenching and tempering in 35 CrNi 3MoV, 4Cr 10Si2 Mo and carbon steels are observed by thin-film transmission electron microscope. The effects of quenching substructures on tempering structure, carbides morphology and distribution conditions and orientation relationships have been found. In quenching twin substructure region, the carbides in tempering structure are mostly platelike and distribute in some straight rows along inner twin boundaries. It has been indicated through electron diffraction that these carbides are mostly M₃C with coherent orientation relationship with matrix. In this case, the structure is analogous to lamellar pearlite; In quenching dislocation substructure region, the carbides in tempering structure are mostly granular and they show disordered distributions along primary dislocaton substructure interfaces. It has been indicated by electron diffraction that these carbides are also mostly one of the M₃C type, but they show an incoherent orientation relationsship with matrix. In this case, the tempering microstructure should be granular sorbite.更多还原