316L不锈钢表面激光熔覆Ni60合金涂层的工艺优化与性能研究  

Process Optimization and Performance Analysis for Laser-Cladding Ni60 Alloy Coating on Surface of 316L Stainless Steel

作　　者：刘丽兰[1] 李思聪 豆卫涛 韩飞燕 林坤[2] Liu Lilan;Li Sicong;Dou Weitao;Han Feiyan;Lin Kun(School of Mechanical and Precision Instrument Engineering,Xi'an University of Technology,Xi'an 710048,Shaanci,China;School of Aeronautical Manufacturing Engineering,Xi'an Aeronautical Polytechnic Institute,Xi'an 710048,Shaanci,China)

机构地区：[1]西安理工大学机械与精密仪器工程学院,陕西西安710048 [2]西安航空职业技术学院航空制造工程学院,陕西西安710089

出　　处：《中国激光》2024年第16期110-123,共14页Chinese Journal of Lasers

基　　金：陕西省教育厅科研计划项目(21JK0705)。

摘　　要：Ni60合金具有硬度高、耐磨耐蚀性强的特点,但其裂纹敏度性高,严重制约了其工程应用进程。笔者以在316L不锈钢表面制备无裂纹Ni60合金熔覆层为目标,提出了以激光功率、扫描速度和送粉速率为输入,以裂纹密度、稀释率和成形系数为优化目标的多元回归预测方法,并采用该方法进行了熔覆工艺参数优化;在无预热条件下,分别进行了单层单道和单层多道激光熔覆试验,然后对试验结果进行分析,总结参数影响规律,并对熔覆层的显微组织和显微硬度进行了研究。结果表明:提高激光功率、减小送粉速率和扫描速度可以降低裂纹密度,增加送粉速率、减小激光功率和扫描速度可以降低稀释率,增加扫描速度和送粉速率、减小激光功率可以增大成形系数;最佳熔覆工艺参数组合为激光功率1405 W、扫描速度5.7 mm/s、送粉速率0.4 r/min,搭接率50%;所获得的熔覆层从结合区至表面,晶粒尺寸逐渐减小,显微组织呈现从平面晶、树枝晶到等轴晶的转变,熔覆层与基体呈良好的冶金结合;Ni60合金熔覆层的显微硬度为641~739 HV,316L不锈钢基体的硬度为219~231 HV,熔覆层硬度约为基体硬度的2.8~3.4倍,表面强化效果明显。Objective Ni60 alloys exhibit high hardness,strong wear,and corrosion resistance.However,based on existing theoretical and practical research,it has been determined that the Ni60 alloy exhibits a high crack sensitivity,which seriously restricts its engineering applications.Orthogonal experiments on laser cladding under non-preheating conditions are conducted,and a multiple regression prediction analysis is adopted to predict the quality of the cladding layers and optimize the process parameters of the laser cladding.High-quality Ni60 cladding layers are beneficial for the wear and corrosion resistance of machine parts fabricated from 316L stainless steel.This study aims to prepare a crack-free Ni60 alloy coating on the surface of 316L stainless steel to promote the application of the Ni60 alloy in the green remanufacturing field.Methods Cracks are mainly caused by residual internal stresses in the cladding layers.They can be avoided by controlling the process parameters,which essentially means controlling the laser energy during the cladding process.Single-layer single-pass and single-layer multipass orthogonal experiments on laser cladding were conducted without preheating.In the experiments,the influences of the powder feeding rate,laser power,and scanning speed on the quality of the cladding layers were examined.The main factor affecting the crack density was obtained via range analysis.Additionally,the effects of the powder feeding rate,laser power,and scanning speed on the dilution rate and forming coefficient were determined based on the geometric morphology of the cladding layers.Multiple regression prediction models were established,which considered the laser power,scanning speed,and powder feeding rate as input factors and the forming quality parameters,such as crack density,dilution rate,and forming coefficient,as optimization goals.Consequently,optimized process parameters for laser cladding were obtained.A crack-free Ni60 alloy coating was prepared using the optimized process parameters.Subsequently,t

关 键 词：激光技术 激光熔覆 NI60合金 316L不锈钢 多目标优化 正交试验 

分 类 号：TG174[金属学及工艺—金属表面处理]