为了提高阀门密封面表面的耐磨性及抗汽蚀性, 以高性能阀门典型用316不锈钢为基体材料, 采用高功率宽带半导体激光器在316基体表面制备了Fe-C-Cr-Si-Mo合金熔覆层。通过显微硬度计、扫描电子显微镜、X 射线衍射仪、摩擦磨损试验机及汽蚀装置对熔覆层的硬度、显微组织、耐磨性和抗汽蚀性能进行了研究。结果表明, 采用优化后激光制造工艺参数, 可获得与基体具有良好冶金结合并且稀释率低的熔覆层。熔覆层平均硬度值达到640 HV0.2, 显著高于基体硬度170 HV0.2。熔覆层硬度较高, 晶粒细化形成了“骨架”支撑了表面以抵御磨损和汽蚀破坏, 从而使得熔覆层的耐磨性提高了3倍左右, 熔覆层磨损机制为磨粒磨损, 抗汽蚀性能较基体提高了2.8倍。

In order to improve the wear resistance of the surface of the valve sealing surface and cavitation resistance, the Fe-C-Cr-Si-Mo alloy was cladded by diode laser on the surface of 316 stainless steel substrate. The microstructure morphologies, phase structure, composition and hardness distribution, wear property, cavitations erosion resistance of the coating were studied by the scanning electronic microscopy(SEM), Energy Dispersive Spectrdmeter(EDS), X-ray diffraction(XRD), micro-hardness tester, friction-abrasion testing machine and the test device for cavitation respectively. The results show that, an excellent metallurgical bonding and low dilution rate between the intermetallic compound layer and the substrates can be obtained by the optimal laser processing parameters. The average value of the cladding coating micro-hardness layer reaches 640 HV0.2, significantly higher than the matrix hardness 170 HV0.2.The microhardness of coating is greatly improved after laser cladding. The refined grain forms a “skeleton” support surface to resist wear and cavitation damage, so that the wear resistance of the cladding coating increases 3 times than that of the substrate. The wear mechanism of cladding coating is dominated by abrasive wear. The cavitation resistance is 2.8 times than that of the substrate.