ER9车轮表面两种激光熔覆涂层海水环境下的摩擦学性能  

Tribological Properties of Two Laser Cladding Coatings on ER9 Wheel Steel Surface in Seawater Environment

作　　者：杨文斌[1,2] 李仕宇 肖乾 陈道云[1] 杨春辉 张博[1] Yang Wenbin;Li Shiyu;Xiao Qian;Chen Daoyun;Yang Chunhui;Zhang Bo(State Key Laboratory of Performance Monitoring and Protecting of Rail Transit Infrastructure,East China Jiaotong University,Nanchang330013,Jiangri,China;Key Laboratory of Urban Rail Transit Intelligent Operation and Maintenance Technology&Equipment of Zhejiang Province,Zhejiang Normal University,Jinhua 321005,Zhejiang,China)

机构地区：[1]华东交通大学轨道交通基础设施性能检测与保障国家重点实验室,江西南昌330013 [2]浙江师范大学浙江省城市轨道交通智能运维技术与装备重点实验室,浙江金华321005

出　　处：《应用激光》2023年第6期19-28,共10页Applied Laser

基　　金：江西省自然科学基金(20202BABL214028);江西省教育厅科学技术研究项目青年项目(GJJ180344);江西省研究生创新专项项目(YC2021-S465)。

摘　　要：研究所设计Fe基和Co基合金激光熔覆层的组织结构及海水环境下摩擦磨损行为,用于解决地铁ER9车轮钢表面防护与修复问题。采用激光熔覆技术在ER9车轮钢表面制备Fe基合金涂层和Co基合金涂层,利用扫描电子显微镜(SEM)、能谱仪(EDS)和X射线衍射仪(XRD)对比分析了两种熔覆层的微观组织结构、物相及化学元素组成,利用往复摩擦试验机考察了其在海水环境下的摩擦学性能。结果表明:在海水环境下的滑动摩擦中,车轮钢基体表面覆盖了大面积腐蚀产物且呈现出大量平行于滑动方向的沟槽。而在两种熔覆涂层中,铁基合金涂层主要由α-Fe、(Fe, Ni)和Cr7C3等固溶体组成,平均硬度(约638.8 HV)相当于基体(284.8~293.2 HV)的2.21倍,摩擦因数约为0.270,磨损率为9.64×10^(-5)mm^(3)/(N·m),磨损机制以轻微磨粒磨损为主,同时伴有腐蚀磨损。钴基合金涂层的结晶相主要是FeNi3相、γ-Co相和Cr23C6相,平均硬度(约467.9 HV)是基体约1.62倍,摩擦因数约为0.225,磨损率为3.06×10^(-5)mm^(3)/(N·m),磨损机制主要为轻微氧化磨损。The microstructure,friction,and wear behavior of Fe-based and Co-based alloy laser cladding layers in a seawater environment were studied and designed to solve the surface protection and repair problems of subway ER9 wheel steel.Fe-based alloy coating and Co-based alloy coating were prepared on the surface of ER9 wheel steel by laser cladding technology,and the microstructure,phase,and chemical element composition of the two cladding layers were compared and analyzed by scanning electron microscope(SEM),energy dispersive spectrometer(EDS),and X-ray diffraction(XRD).The tribological properties of the two coatings in a seawater environment were investigated by reciprocating friction testers.The results show that in the sliding friction in a seawater environment,the surface of the wheel steel substrate is covered with a large area of corrosion products and presents a large number of grooves parallel to the sliding direction.In the two cladding coatings,the iron-based alloy coating is mainly composed of solid solutions such asα-Fe,(Fe,Ni)and Cr_7C_3,and the average hardness(about 638.8 HV)is equivalent to that of the matrix(284.8~293.2 HV)2.21 times,the friction coefficient is about 0.270,the wear rate is 9.64×10^(-5)mm^3/(N·m),the wear mechanism is mainly slight abrasive wear,accompanied by corrosion wear.The crystal phases of the cobalt-based alloy coating are mainly the FeNi_3 phase,γ-Co phase,and Cr_(23)C_6 phase,the average hardness(about 467.9 HV)is about 1.62 times that of the matrix,the friction coefficient is about 0.225,and the wear rate is 3.06×10^(-5)mm^3/(N·m).The wear mechanism is mainly slight oxidative wear.

关 键 词：激光熔覆 海水 铁基合金涂层 钴基合金涂层 微观组织 摩擦磨损 

分 类 号：TG174.4[金属学及工艺—金属表面处理]