采用光纤激光器对卷取机卷筒主轴常用的40CrNiMoA钢进行了激光淬火实验,采用金相显微镜观察试样表面的显微组织,采用维氏硬度计测试相变硬化层的显微硬度,采用立式万能摩擦磨损试验机评估试样的摩擦磨损性能,采用体视显微镜观察试样截面的宏观组织及磨损形貌,采用电化学工作站测试试样的耐蚀性能。结果表明:40CrNiMoA钢经激光淬火后,表面会出现一层相变硬化层,其显微组织主要为细小的马氏体、少量的残留奥氏体以及部分弥散的碳化物;硬化层深度约为200 μm,硬度值可达638.3~711.2 HV,约为基体的2.6~2.8倍;平均摩擦因数为0.506,与基体相比下降了42.5%,磨损量为1.3 mg,仅为基体的36.1%,其主要磨损机制为磨粒磨损;腐蚀电位为-0.497 V,自腐蚀电流密度为2.16789×10 -9 A/cm 2,与基体相比,腐蚀电位略有提高,而自腐蚀电流密度有所降低,耐腐蚀性能得到了较大提升。

In this study, a laser-quenching experiment is conducted on the 40CrNiMoA steel base material of a reel spindle using a fiber laser. Further, the microstructure of sample surface is observed using a metallographic microscope, the microhardness of the phase-transformation hardening zone is evaluated using a Vickers hardness tester, and the friction and wear properties of the sample are evaluated using a vertical universal friction-and-wear tester. The macroscopic structure of the sample cross-section and morphology after wear are observed using a stereo microscope, and the corrosion resistance of the sample is verified using an electrochemical workstation. The results denote that after laser quenching of the 40CrNiMoA steel, a phase-transformation hardening zone can be observed on the surface with a microstructure that is mainly characterized by fine martensite, a small amount of retained austenite, and partially dispersed carbides. The hardened layer exhibits a depth of approximately 200 μm, and the hardness can become 638.3--711.2 HV, which is approximately 2.6--2.8 times that of the substrate. The average friction coefficient is 0.506, which is 42.5% lower than that of the substrate. The amount of wear is 1.3 mg, which is only 36.1% of that of the substrate. Herein, the abrasive wear is observed to be the main wear mechanism. Furthermore, the corrosion voltage is -0.497 V, which is slightly higher than that of the substrate, while the self-corrosion current density is 2.16789×10 ^-9 A/cm ², which is lower than that of the substrate. The corrosion resistance is considerably improved.