激光熔覆修复45#钢模具的组织及性能研究

Research of Microstructure and Properties of Repairing 45# Steel Mold on Laser Cladding

目的利用IPG光纤激光器YLR-3000激光加工系统,激光熔覆自熔性镍基碳化钨粉末修复45#钢模具磨破损区域。方法采用两种方法对磨破损区域进行修复,洛氏硬度机(HR-150DT)、显微硬度计(HVS-1000)和蔡司高级金相显微镜对熔覆熔覆层的表面硬度、金相组织和显微硬度分析对比。结果,在同一工艺参数(激光功率1200W、扫描速度2mm/s、送粉电压7V)下,磨破损区域选择环状进行修复较好,熔覆层宏观表面相对平整光滑,熔覆层的平均洛氏硬度约是基体平均硬度的2.5倍;熔覆层微观组织分析可知:熔覆层及界面处无裂纹、气孔等缺陷,熔覆层中上部分组织晶粒细小,沿熔覆层与基体交界处向外晶粒呈现柱状晶及等轴晶,组织性能良好,基体与熔覆层间冶金结合比较牢固,熔覆层显微硬度分布比较均匀并且与基体相比提高约3倍。结论利用激光熔覆技术修复模具磨破损区域具有应用价值。

It uses IPG fiber laser YLR-3000 laser processing system on 45 # steel mold surface by laser cladding self-fluxing Ni - based WC powders. There are two ways to repair the damaged area of the mold, Rockwell hardness machine （HR-150DT）, Micro Hardness Tester （HVS-1000）, and advanced Zeiss microscope analysis of cladding cladding of surface hardness, metallurgical structure and microhardness. When laser is power 1200W, scanning speed 2mm/s, powder feeding voltage 7v, choosing ring to repair the damaged area of the mold is better. Cladding is relatively smooth on macro surface, and the average Rockwell hardness of the cladding layer is about 2.5 times the average hardness of the matrix; cladding microstructure analysis shows ： cladding layer and the interface crack-free ,holes and other defects ,cladding layer on the part of the organization small grains,cladding layer and the substrate along the junction of outward grain present dendritic equiaxed, and good organizational performance, and cladding layer is between the substrate and the relatively strong metallurgical bond. Cladding layer hardness is of more evenly distributed and, compared with the base increases by 3 times. Repairing the damaged area of mold by laser cladding technique has application value.