采用RFL - C3300光纤激光器对42CrMo钢表面进行激光淬火处理,通过扫描电镜、光学显微镜、体视显微镜、维氏硬度计及立式万能摩擦磨损试验机进行检测,分析淬硬层组织、硬度、深度、耐磨性与激光工艺参数之间的关系。结果表明:试样经过激光淬火处理后,表层组织得到细化,表面硬度和耐磨性都得到了提升,激光功率为2 200 W,扫描速度为20 mm/s,当光斑尺寸为12 mm×2 mm时,试样表层组织由细小的马氏体组织、少量残余奥氏体和弥散细小碳化物组成,其表面平均硬度达到660 HV2 N,约为基体硬度的2.6倍,摩擦系数稳定在0.4~0.6,比基体降低了25%左右,磨损量为0.5 mg,为基体的23.8%。
The laser quenching treatment of 42CrMo steel surface was carried out with a RFL - C3300 fiber laser, and the relations between the microstructure, hardness, depth, wear resistance of the hardened layer and the laser process parameters were analyzed by scanning electron microscope, optical microscope, stereomicroscope, vickers hardness tester and vertical universal friction and wear tester. Results showed that after laser quenching, the surface microstructure of the sample was refined, and the surface hardness and wear resistance were improved. When the laser power was 2 200 W, the scanning speed was 20 mm/s and the spot size was 12 mm × 2 mm, the surface microstructure of the sample was composed of fine martensites, a small amount of retained austenites and dispersed fine carbides. The average surface hardness reached 660 HV2 N, which was about 2.6 times that of the matrix. The friction coefficient stabilized at 0.4~0.6, which was about 25% lower than that of the matrix. The wear amount was 0.5 mg, which was 23.8% of that of the matrix.