扫描速度对300M钢熔覆C276涂层组织及性能的影响

为了提升300M超高强度钢表面的耐蚀性能，在300M钢表面通过激光熔覆技术制备出四组扫描速度分别为5 mm/s,8 mm/s,11 mm/s和14 mm/s的涂层试样，通过光学显微镜、扫描电镜、X射线衍射仪、EDS能谱仪、显微硬度仪、摩擦磨损机、电化学工作站仪器分别表征涂层的宏观形貌、显微组织、物相组成、元素分布、硬度性能、摩擦磨损性能和耐腐蚀性能。结果表明，300M钢熔覆C276后，涂层的耐蚀性和硬度都得到增强，但耐磨性能较原基体变差，涂层形貌受扫描速度的影响，扫描速度越大，平整度越趋于平整，且金属光泽也逐渐加深，同时在不同参数下的涂层物相种类未发生明显变化，主相均为Ni-Cr-Co-Mo，在扫描速度8 mm/s的参数下，涂层具有最高的硬度较基体提升约36.2%，同时也具有更佳的耐蚀性能与其他力学性能。

Effect of scanning speed on microstructure and properties of 300M steel cladding C276 coating

In order to improve the corrosion resistance of the surface of 300M ultra-high strength steel, four sets of coating samples with scanning speeds of 5 mm/s, 8 mm/s, 11 mm/s and 14 mm/s were prepared on the surface of 300M steel by laser cladding technology. The specimen was characterized by optical microscope, scanning electron microscope, X-ray diffractometer, EDS energy dispersive spectrometer, microhardness tester, friction and wear machine and electrochemical workstation instrument, respectively, to characterize the macroscopic morphology, microstructure, phase composition, element distribution, hardness properties, friction and wear properties and corrosion resistance of the coating. The results show that after 300M steel is cladded with C276, the corrosion resistance and hardness of the coating are enhanced, but the wear resistance is worse than that of the original substrate, and the coating morphology is affected by the scanning speed. The greater the scanning speed, the flatness tends to be flatter, and the metallic luster is gradually deepened. At the same time, the phase types of the coating did not change significantly under different parameters, and the main phase was Ni-Cr-Co-Mo. Under the parameter of the scanning speed of 8 mm/s, the coating layer having the highest hardness is about 36.2% higher than that of the matrix, and it also has better corrosion resistance and other mechanical properties.