Optimization of laser cladding process parameters for Fe-based alloy based on NSGA-Ⅱ

基于NSGA-Ⅱ的Fe基合金激光熔覆工艺参数优化 Optimization of laser cladding process parameters for Fe-based alloy based on NSGA-Ⅱ 宋少东 SONG Shaodong 1 first-author 王燕燕 WANG Yanyan 1 舒林森 SHU Linsen 1 2 何雅娟 HE Yajuan 1 陕西理工大学机械工程学院 陕西理工大学机械工程学院 College of Mechanical Engineering,Shaanxi University of Technology College of Mechanical Engineering,Shaanxi University of Technology 陕西省工业自动化重点实验室 陕西省工业自动化重点实验室 Shaanxi Key Laboratory of Industrial Automation Shaanxi Key Laboratory of Industrial Automation 工艺参数是保证激光熔覆修复阀门类零件质量的关键因素。以激光功率、扫描速度、送粉速度、离焦量为自变量,熔池深度、显微硬度、稀释率为优化目标,基于正交试验研究了工艺参数对40Cr基材上熔覆Fe基合金粉末性能的影响规律。采用逐步回归分析建立了稀释率、熔池深度、显微硬度的回归方程,最后通过NSGA-Ⅱ智能算法进行优化,得到了最优工艺参数并进行了试验验证。结果表明:熔覆层稀释率及显微硬度的主要影响因素为送粉速度,而对熔池深度影响最大的因素为激光功率,在激光功率2 182 W、扫描速度17.2 mm/s、送粉速度18.4 g/min、离焦量1.86 mm时,熔覆层形貌大为改善,稀释率为20.3%,熔池深度为373μm,显微硬度提高了21.7%,修复质量得到了有效提高。 Process parameters are the key factors to ensure the quality of valve parts repaired by laser cladding.Therefore, with laser power, scanning speed, powder feeding speed and defocus amount as independent variables, and pool depth, micro hardness and dilution rate as optimization objectives, the influence of process parameters on the cladding of Fe-based alloy powder on 40Cr substrate was studied based on orthogonal experiment. The regression equations of dilution rate, depth of molten pool and micro hardness were established by stepwise regression analysis. Finally, a set of optimal process parameters were obtained by the intelligent algorithm of NSGA-Ⅱ and verified by experiments. The results show that the main factor for the dilution rate and micro hardness of the cladding layer is the powder feeding speed, and the most important factor for the depth of the molten pool is the laser power. The optimal process parameters obtained by NSGA-Ⅱare as follows: the laser power is 2 182 W, the scanning speed is 17.2 mm/s, the powder feeding speed is 18.4 g/min, and the defocusing amount is 1.86 mm. Under these parameters, the morphology of the cladding layer is greatly improved, the dilution rate is 20.3%, the depth of the molten pool is 373 μm, the micro hardness is increased by 21.7%, and the repair quality is effectively improved. 激光熔覆 工艺优化 NSGA-Ⅱ 极差分析 laser cladding process optimization NSGA-Ⅱ range analysis TG665;TG174.4 国家自然基金青年基金(51505268);陕西省教育厅专项科研计划项目(18JK0150) 2022-03-08 12 51