锰硅系贝氏体/马氏体复相钢中贝氏体精细结构的研究

THE FINE STRUCTURE OF THE BAINITE/MARTENSITE DUAL PHASE STEEL

利用原子力显微镜（ＡＦＭ）、扫描隧道显微镜（ＳＴＭ）、透射电子显微镜（ＴＥＭ）、光学显微镜（ＯＭ）等分析手段对锰硅系贝氏体／马氏体复相钢中贝氏体的结构进行了研究．观察到低碳锰硅钢中的贝氏体组织由亚片条、亚单元组成．利用原子力显微镜（ＡＦＭ）及透射电子显微镜（ＴＥＭ）在贝氏体工单元中发现有以残余奥氏体膜为分界面的精细结构的存在观测结果可用贝氏体相变的激发形核－台阶长大机制做合理解释．为锰硅系贝氏体／马氏体复相钢的合金组织设计、组织结构和性能关系的研究提供了实验依据．

Fine structures of bainite-martensite steel are investigated by using transmission electron microscopy (TEM), atom force microscopy (AFM) and scanning electron microscopy (STM). The bainitic microstructure is an aggregation of plates in a form of sheaves, and the individual plate is consisting of several subunits. The subunits of bainite further consist of smaller structure units which are separated by residual austenite films. The observed results can be explained rationally with the sympathetic nucleation-ledgewise mechanism of bainite transformation. It is helpful to further understanding of the microstructure evolutin of bainite/martensite dual phase steels.