熔覆电流对高钼高钒铁基硬质涂层组织结构与性能的影响  

Effect of Cladding Current on the Microstructure and Properties of Fe-based Hard Coatings with High Mo and V Contents

作　　者：张顶 宋庆雷 张平[1] 郭喜平[2] 柳学强 沈承金[1] ZHANG Ding;SONG Qinglei;ZHANG Ping;GUO Xiping;LIU Xueqiang;SHEN Chengjin(School of Materials Science and Physics,China University of Mining and Technology,Xuzhou 221116,China;State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi'an 710072,China;Xuzhou BUT Construction Machinery Joint-Stock Co.,Ltd.,Xuzhou 221005,China)

机构地区：[1]中国矿业大学材料与物理学院,江苏徐州221116 [2]西北工业大学凝固技术国家重点实验室,陕西西安710072 [3]徐州巴特工程机械股份有限公司,江苏徐州221005

出　　处：《铸造技术》2024年第6期557-564,共8页Foundry Technology

基　　金：国家自然科学基金(52271081);凝固技术国家重点实验室开放课题(SKLSP202307)。

摘　　要：刃板的磨损失效往往导致整个挖斗报废,为了提高其耐磨性能,采用等离子熔覆技术在刃板材料Q345B表面制备高钼高钒铁基耐磨涂层,研究熔覆电流(120、140、160 A)对涂层组织结构的影响,考察涂层的显微硬度、摩擦磨损与耐冲击性能。结果表明,电流大小对涂层的组织结构与界面状态影响较大,涂层组织主要由马氏体基体、弥散分布的细小球形碳化钒(VC)、多边形块状硼化钼(Mo_(2)B)和层片状复合硼碳化物(M_(2)(B,C))组成。120 A下制备的涂层与基材界面处存在局部未熔合区,增大电流导致涂层中VC的尺寸和分布间距变大,Mo_(2)B消失,M_(2)(B,C)增多且尺寸增大。涂层的平均显微硬度约为920 HV0.1,是耐磨钢NM400的2倍多,同等条件下的磨损失重仅为NM400的1/20,表现出优异的耐磨性能。带基材的涂层具有良好的耐冲击性能,且平行熔覆纹路的耐冲击性能优于垂直熔覆纹路的。To improve the wear resistance of cutting edge plates on digging buckets,Fe-based hard coatings with high Mo and V contents were prepared on Q345B steel by plasma cladding technology.The effects of cladding current(120,140,160 A)on the structure of the coatings were analysed,and the hardness,wear resistance and impact resistance of the coatings were investigated.The results show that the cladding current has a significant influence on the microstructure and interface quality of the coatings.The coatings mainly consist of a martensitic matrix with distributed fine spherical VC particles,polygonal Mo_(2)B and lamellar composite M_(2)(B,C).Localized unfused zones are observed at the interface between the substrate and the coating prepared at 120 A.As the current increases,the size of the VC particles in the coatings increases,their distribution density decreases,and the size of Mo_(2)B decreases or even disappears in the coating prepared at 160 A,while the size of M_(2)(B,C)increases and the number increases.The average hardness of the coatings is approximately 920 HV0.1,which is more than twice that of NM400 steel,and the weight loss is only 1/20 of that of NM400 under the same abrasion conditions,showing better wear resistance.The coating specimens exhibit good impact resistance,and the coatings with parallel cladding patterns are superior to those with vertical cladding patterns.

关 键 词：等离子熔覆 高钼高钒铁基硬质涂层 组织结构 耐磨性能 熔覆纹路 

分 类 号：TG174.4[金属学及工艺—金属表面处理]