超低碳马氏体的EBSD结构表征

EBSD characterization on the structure of ultra-low carbon martensite

通过EBSD等实验手段研究了超低碳马氏体钢的结构特征及奥氏体形变对其结构和性能的影响。结果表明,超低碳马氏体具有多尺度结构,从大到小依次为原始奥氏体晶粒→板条束→板条块→亚板条块→板条;奥氏体无变形时,超低碳马氏体的板条块宽度大于传统低碳马氏体,导致其强度增量较低;奥氏体形变能够明显细化超低碳马氏体板条块,从而提高其强度。

The microstructures of ultra-low carbon martensite（ULCM） steels with and without austenite deformation were investigated by using EBSD.The results show that the ULCM has a multi-scaled structure,i.e.,prior-austenite grain,packet,block,sub-block and lath.The width of ULCM block is larger than that of conventional low carbon martensite,resulting in lower strengthening increment.Austenite deformation before transformation can refine the block width significantly,resulting in increasing the strength of ULCM steel.