激光熔覆Fe-Ti-V-C合金微观组织与磨损性能  

Microstructure and Wear Resistance of Fe-Ti-V-C Hardfacing Alloys by Laser Cladding

作　　者：宗琳[1] 李荣广[1] 张小玲[1] ZONG Lin LI Rongguang ZHANG Xiaoling(School of Mechanical Engineering, Shenyang University of Chemical Technology, Shenyang 110142)

机构地区：[1]沈阳化工大学机械工程学院,沈阳110142

出　　处：《机械工程学报》2017年第2期67-73,共7页Journal of Mechanical Engineering

基　　金：辽宁省博士科研启动基金资助项目(20141082)

摘　　要：采用激光熔覆技术在20G基体上制备五组不同Ti质量分数的Fe-Ti-V-C系合金,利用金相显微镜、扫描电子显微镜、X射线衍射仪、显微硬度计和磨料磨损试验机等仪器对各熔覆层的显微组织、硬度和耐磨性进行测试和分析。试验结果表明:五组合金熔覆层基体组织均由铁素体和马氏体构成;随着熔覆层中Ti质量分数的增加,针状马氏体基体组织转变为板条马氏体;初生(Ti,V)C的形态由树枝状和花瓣状向颗粒状转变,同时碳化物(Ti,V)C的数量逐渐增多,当Ti质量分数为14.7%时,碳化物的数量达到最高值。熔覆层截面显微硬度梯度分布合理,表层硬度达到700~950 HV0.2。湿砂磨粒磨损试验表明:适量Ti显著提高了熔覆层的耐磨性,熔覆层中随着Ti质量分数的提高,耐磨性先降低后提高,当Ti质量分数为14.7%时,大量颗粒状(Ti,V)C均匀弥散分布在铁素体及板条马氏体基体上,使得熔覆层具有最佳的耐磨性。A series of Fe-Ti-V-C hardfacing alloys with five different Ti contents were deposited on the surface of 20G steel by laser cladding. Microstructure, hardness and wear resistance were investigated using optical microscope（OM）, scanning electron microscopy（SEM）, X-ray diffraction（XRD）, microhardness tester and abrasive wear testing machine. The results shows that the matrix is composed of ferrite and martensite, the matrix microstructure changes from acicular martensite to lath martensite, the morphology of primary （Ti,V）C changes from dendritic and flower-like shapes to globular shape and the volume fraction of primary （Ti,V）C complex carbides increase as the Ti content increase, the maximum volume fraction of primary （Ti,V）C complex carbides are attained when the Ti content is 14.7%. The microhardness of the cladding layer cross section appears reasonable gradient distribution, the microhardness of the surface layer reaches 700-950 HV0.2. The results of wet sand rubber wear tests indicate that addition of proper Ti element into hardfacing alloys effectively enhances the wear resistance of alloys. When 14.7% Ti content is added, the cladding layer has an excellent wear resistance, which is attributed to the more globular （Ti,V）C complex carbides distributed uniformly and dispersely in the ferrite and lath martensite matrix.

关 键 词：激光熔覆 耐磨性 显微组织 Fe-Ti-V-C合金 

分 类 号：TG176[金属学及工艺—金属表面处理]