研究了不同工艺条件下T10/Q235复合钢板的激光淬火行为, 分析了淬硬层的显微组织及硬度特征。结果表明, 单道扫描激光淬火时, 淬火区组织主要为针状马氏体＋少量残余奥氏体, 表层马氏体较心部粗大, 过渡区组织为针状马氏体＋残余奥氏体+少量碳化物; 多道扫描激光淬火时, 淬火区组织与单道扫描激光淬火时基本相同, 回火区则主要为回火索氏体及回火马氏体。硬化层硬度随离表面距离增加呈递减趋势变化, 但最大硬度出现在次表层; 随着扫描速度增大, 硬度存在一极值。多道扫描激光淬火时, 淬火区和回火区交替出现, 回火区硬度有大幅下降, 但其分布趋势与淬火区相反。

The laser quenching behavior of T10/Q235 clad steel under different process conditions is researched. The microstructure and hardness characteristics of the hardened layer are analyzed. The results show that in single-pass laser quenching, microstructure of the quenched zone is mainly comprised martensite and a small amount of retained austenite. The surface martensite is coarser than the core, and the transition zone is acicular martensite, residual austenite and a small amount of carbides. In multi-pass laser quenching, microstructure of the quenched zone is basically the same as single-pass laser quenching, and the tempering zone is mainly tempered sorbite and tempered martensite. The hardness of hardened layer decreases gradually with increasing distance from the surface, but the maximum hardness appears in the subsurface layer. As the scanning speed increases, the hardness has an extreme value. In multi-pass laser quenching, the quenching zone and the tempering zone appears alternately, and the hardness of the tempering zone decreases significantly, but the distribution trend is opposite to the quenching zone.