首先对贝氏体扩散控制台阶长大机制进行简要评述.认为台阶的存在并不能证明扩散控制台阶长大机制,提出了贝氏体相变过程中新相沿母相奥氏体层错面切变增厚的观点.在这种模型中,由于贝氏体铁素体片增厚借助于界面位错圈在奥氏体层错面上的扩展来完成,台阶的运动只能沿母相层错面切变滑移,而不会作侧向迁移,同时台阶侧面也不应是无序的非共格界面,切变运动的结果导致下贝氏体发生台阶与奥氏体层错条纹具有对应关系的实验现象.“,”The diffusion controlled ledge growth mechanism of bainite (DCLGMB) is reviewed briefly in this paper. It is argued that the existence of the ledge can not prove the existence of DCLGMB. A growth mode of lower bainite by shearing on the stacking fault face of austenite is proposed. In this mode, the thickening of lower bainite depends on the interfacial misfit dislocation loop (IMDL), which expands on the stacking fault faces of austenite. Ledges move only along the stacking fault faces but not along the si...