超高速激光熔覆制备M2涂层的组织结构与性能研究  

Study on the Structure and Properties of M2 Coating Prepared by Ultrahigh-Speed Laser Cladding Technology

作　　者：王景诗 葛成杰 张勤号 任潞 陈秀勇 所新坤 WANG Jingshi;GE Chengjie;ZHANG Qinhao;REN Lu;CHEN Xiuyong;SUO Xinkun(School of Mechanical,Engineering and Mechanics,Ningbo University,Ningbo 315211,China)

机构地区：[1]宁波大学机械工程与力学学院多维增材制造研究所,浙江宁波315211

出　　处：《材料保护》2024年第10期152-161,207,共11页Materials Protection

基　　金：国家自然科学基金(52171072)。

摘　　要：超高速激光熔覆技术作为一种新型的表面工程技术,具有快速加工、精密控制、热影响小等优点,适用于多种材料表面的涂层制备。为了研究熔覆速度对M2涂层组织结构和性能的影响,利用超高速激光熔覆技术在Q235钢表面制备了M2涂层。利用扫描电子显微镜、X射线衍射仪、硬度计、摩擦磨损仪、电化学工作站分别测试了涂层的微观组织、物相组成、硬度、耐磨性和耐腐蚀性。结果表明:熔覆速度为1.2 m/min时,涂层与基体结合无缝隙,显微硬度为757.1 HV,摩擦系数为0.448,腐蚀电流密度J_(corr)为1.98×10^(-6)A/cm^(2);随着熔覆速度的提高,涂层与基体结合处出现缝隙,晶粒减小,稀释率减小,硬度增大,摩擦系数减小;当熔覆速度为40.0 m/min时,涂层与基体结合处出现较大裂纹,此时晶粒等效平均直径为1.76μm,稀释率为6.8%,平均显微硬度828.1 HV,平均摩擦系数为0.345,腐蚀电流密度J_(corr)为1.26×10^(-7)A/cm^(2)。熔覆速度对超高速激光熔覆涂层的宏观形貌和性能的影响较大。随着熔覆速度的增大,涂层区域出现裂纹。随着熔覆速度的提高,涂层的晶粒等效直径减小,硬度、耐磨性、耐腐蚀性均提高。各涂层的物相组成均为马氏体、残余奥氏体和碳化物。本工作为M2高速钢涂层的制备和参数优化提供了理论依据。As a new type of surface engineering technology,ultrahigh-speed laser cladding technology has the advantages of rapid processing,precision control,and low thermal influence,which is applicable to the preparation of coatings on a variety of materials.In order to study the effect of cladding speed on the microstructure and properties of M2 coatings,M2 coatings were prepared on the surface of Q235 steel using ultrahigh-speed laser cladding technology.The influence of cladding speed on the microstructure and properties of the coatings was studied.The microstructure,phase composition,hardness,wear resistance,and corrosion resistance of the coatings were tested using scanning electron microscopy(SEM),X-ray diffraction(XRD),a hardness tester,a tribometer,and an electrochemical workstation,respectively.Results showed that at a cladding speed of 1.2 m/min,the coating was seamlessly bonded to the substrate,with a microhardness of 757.1 HV,a fric-tion coefficient of 0.448,and a corrosion current density Jcorr of 1.98×10^(-6)A/cm^(2).As the cladding speed increased,gaps appeared at the coating-substrate interface,grain size decreased,dilution rate decreased,hardness increased,and friction coefficient decreased.At a cladding speed of 40.0 m/min,larger cracks formed at the coating-substrate interface,with an equivalent average grain diameter of 1.76μm,a dilution rate of 6.8%,an average microhardness of 828.1 HV,an average friction coefficient of 0.345,and a corrosion current density Jcorr of 1.26×10^(-7)A/cm^(2).The cladding speed had a significant impact on the macroscopic morphology and performance of the ultra-high-speed laser clad-ding coatings.With increasing cladding speed,cracks appeared in the coating region,while the equivalent diameter of the grains decreased and the hardness,wear resistance,and corrosion resistance improved.The phase composition of all coatings consisted of martensite,retained aus-tenite,and carbides.This work provides a theoretical basis for the preparation and parameter optimization of M2 high-

关 键 词：激光熔覆 M2高速钢 微观结构 力学性能 界面结合 

分 类 号：TG174.4[金属学及工艺—金属表面处理]