磨损是机械零件的主要失效方式之一, 在矿山、冶金和电力等工业领域, 有很多设备都是在服役环境异常恶劣的冲击磨料磨损条件下进行工作的。为了在廉价的钢材上制备出性能优异的抗磨料磨损性能的涂层, 采用激光熔覆工艺在45#钢表面制备了St6钴基合金激光熔覆层。利用扫描电镜(SEM)、光学显微镜(OM)、X射线衍射仪(XRD)、显微硬度计和MLD-10型动载磨料磨损试验机分析了熔覆层的显微组织, 测试了涂层的显微硬度和冲击磨料磨损性能。结果表明：涂层与基体形成了冶金结合, 涂层无裂纹、气孔等缺陷; 激光熔覆层的显微硬度为700~715 HV, 激光熔覆St6钴基合金层有效提高了45#钢零件的抗冲击磨料磨损性能。

Abrasion failure is a key failure form for mechanical parts in the field of mine、 metallurgy and electric powder. A lot of equipments serve under service impact abrasive wear environment. In order to improve the impact abrasive wear resistance of cheap steel materials, laser cladding of St6 alloy powders on 45 steel was conducted, The microstructure, hardness, impact abrasive wear resistance of cladding layer were researched by scanning electron microscope, optical microscope, X-ray diffractometer, micro-hardness tester and MLD-10 type impact wear test machine. The results show that there was a good metallurgical bond between coating and substrate and the coating was free of cracks and pores. The micro-hardness of laser clad layer is 700~716 HV. St6 alloy laser cladding coating can effectively improve the impact abrasive wear resistance of 45 steel parts.