针对三光束光内送丝熔覆工艺的温度场进行研究,并对其工艺参数进行优化。建立了三光束光源的热源模型,利用ANSYS软件对熔池的温度场进行仿真,并结合工艺实验分析了离焦量、激光功率和扫描速度等工艺参数对熔覆层形貌的影响。仿真及实验结果表明:离焦量对熔覆层高度的影响较大,且会影响稀释区的形貌特征,激光功率主要影响熔覆层的稀释率,扫描速度对熔覆层高度的影响较大,扫描方向的改变对熔覆层稀释区有一定的影响;在离焦量为-2 mm、激光功率为1500 W、扫描速度为5 mm/s的条件下进行熔覆实验,得到的熔覆层平整光滑,无明显的熔覆缺陷,熔覆层组织为马氏体,硬度为411 HV,硬度的分布较为均匀。

The temperature field is studied and the process parameters are optimized for the laser cladding based on the internal wire feeding of three beams. A heat source model of the three beams is established. The temperature field of the molten pool is simulated by using the ANSYS software. The effects of defocusing amount, laser power, and scanning speed on the morphology of the cladding layer are analyzed by experiments and simulations. The simulation and experimental results demonstrate that the defocusing amount considerably impacts the width of the cladding layer and the morphology of the dilution zone. The laser power mainly affects the dilution rate of the cladding layer, and the scanning speed considerably impacts the height of the cladding layer. Further, the change of the scanning direction impacts the dilution area of the cladding layer. The experiments are performed under a defocusing amount of -2 mm, a laser power of 1500 W, and a scanning speed of 5 mm·s ^-1. The cladding layer is smooth and exhibits no obvious cladding defects. The cladding layer structure is martensite, the hardness is 411 HV, and the hardness distribution is relatively uniform.