利用6 kW光纤激光器在Cr12MoV模具钢表面激光熔覆Fe-Cr-B合金涂层。运用金相显微镜和显微硬度仪,研究了激光功率、扫描速度、送粉率对熔覆层成形、尺寸、稀释率及组织结构和微观硬度的影响。结果表明:熔覆层组织主要由平面晶、树枝晶和等轴晶构成。理想的工艺参数为激光功率(P)2000 W,扫描速度(V1)4 mm/s,送粉率(V2)15 g/min。该工艺参数下熔覆层晶粒细小,与基体呈现良好冶金结合,稀释率为9.8%,熔覆层显微硬度平均高达1000 HV。 Laser Cladding Fe-Cr-B Alloy Coating on Cr12MoV Mold Steel Surface with a 6 kW Fiber Laser. The effects of laser power, scanning speed and powder feeding rate on the forming, size, dilution rate, microstructure and microstructure of cladding layer were studied by using optical microscope and microhardness tester. The results show that the microstructure of cladding layer consists of plane crystal, dendrite and equiaxed crystal. The ideal process parameters are laser power (P) 2000 W, scanning speed (V1) 4 mm / s, feeding rate (V2) 15 g / min. Under the process parameters, the cladding layer has fine grains and good metallurgical bonding with the matrix, with a dilution rate of 9.8% and an average microhardness of the cladding layer of up to 1000 HV.