采用硬度测试、显微组织和断口分析,对经激光淬火处理后的9Cr2Mo冷轧辊用钢进行了研究。结果表明,与常规淬火相比,9Cr2Mo钢激光淬火后硬度明显提高,但激光淬火搭接区出现硬度值陡降,其原因为搭接区的马氏体组织回火分解;常规淬火处理后的9Cr2Mo钢内有条、块状碳化物,断口为脆性解理断裂特征;而激光淬火后,条块状碳化物溶解或部分溶解,未完全溶解的碳化物细化成球形颗粒,其断口为浅韧窝+脆性准解理的断裂特征。 The hardness of 9Cr2Mo cold rolled steel after laser quenching was studied by hardness test, microstructure and fracture analysis. The results show that compared with conventional quenching, the hardness of 9Cr2Mo steel increases obviously after laser quenching. However, the hardness value of laser quenching lap area decreases sharply, which is due to the tempering of martensite structure in lap joint area. After quenching In 9Cr2Mo steel, there is a strip of massive carbides and the fracture is characterized by brittle cleavage fracture. After laser quenching, the massive carbides dissolve or partially dissolve. The incompletely dissolved carbides are refined into spherical particles and the fracture is shallow and tough Fracture characteristics of dimple + brittle quasi - cleavage.