Cr对Fe-B-C-Mn-Si系堆焊合金的M2B相及耐磨性影响  

Effect of Cr on MB phases and abrasion resistance of Fe-B-C-Mn-Si system hardfacing alloys

作　　者：程诗尧 龚建勋[1] 刘超 黄洪江 CHENG Shiyao;GONG Jianxun;LIU Chao;HUANG Hongjiang(School of Mechanical Engineering,Xiangtan University,Xiangtan 411105,China)

机构地区：[1]湘潭大学机械工程学院,湖南湘潭411105

出　　处：《兵器材料科学与工程》2020年第5期80-85,共6页Ordnance Material Science and Engineering

基　　金：湖南省自然科学湘潭联合基金(2015JJ5031)。

摘　　要：以复合粉粒和H08A实心焊丝为焊接材料,在Q235A基体上埋弧堆焊Fe-Cr-B-C-Mn-Si系耐磨合金,借助光学显微镜、X射线衍射仪、扫描电镜及附属电子能谱仪等,研究高Cr含量对合金M2B相及耐磨性的影响。结果表明:该合金基体由马氏体和铁素体组成,硬质相包括M2B、M3(C,B)和M3B4等,其中M代表Fe、Cr等元素;随Cr含量提高,初生M2B相由特征衍射峰指数与Fe2B相同的(Fe,Cr)2B相转变为与CrFeB相近的(Cr,Fe)2B相,显微硬度均值从1 026HV增加至1 622HV;合金耐磨性先显著提升后小幅下降,显著提升的主要原因与其初生M2B的显微硬度大幅提高有关,随后小幅下降与二次M2B相的尺度减小相关;合金主要磨损机制随Cr含量提高由显微剥落转变为微切削形式。Fe-Cr-B-C-Mn-Si system wear-resisting alloys,in which composite powder particles and H08 A solid wire were used as welding consumables,were deposited on Q235 A base metals by the method of submerged arc welding.The effect of high chromium content on M2 B phases and their abrasion resistance were investigated by optical microscopy(OM),X-ray diffractometer(XRD),scanning electron microscopy(SEM) as well as energy dispersive spectrometer(EDS).The results indicate that the microstructure of the deposited metal is characterized by martensite and ferrite matrix,decrated with hard phase,including M2 B,M3(C,B),M3 B4(M represent the elements such as Fe,Cr).With the increasing of chromium content,the primary M2 B phases in hardfacing alloys change from(Fe,Cr)2 B to(Cr,Fe)2 B.Their micro-hardness average value increases from 1 026 HV to 1 622 HV.The results of wear tests show that increasing Cr content to a critical value can lead to a significant increase in wear resistance of the deposited metal,arising from the increase in hardness of primary M2 B.However,further increasing Cr content results in a slight decrease of wear resistance of the deposited metal,due to the decrease in size of secondary M2 B.The wear morphologies indicate that with the increasing Cr content the wear mechanism of the deposited metal will transform from micro-spalling to micro-cutting manner.

关 键 词：堆焊 耐磨 复合粉粒 实心焊丝 硼合金 

分 类 号：TG423[金属学及工艺—焊接]