B元素对Cr-Ni-Mo-Mn系药芯焊丝堆焊金属组织结构的影响  

Effect of B element on microstructure of Cr-Ni-Mo-Mn series coating metal by surfacing with flux-cored wire

作　　者：裘荣鹏[1] QIU Rongpeng(Liaoning Equipment Manufacturing Vocational and Technical College,Shenyang 110161,China)

机构地区：[1]辽宁装备制造职业技术学院,辽宁沈阳110161

出　　处：《电焊机》2020年第8期27-30,I0004,共5页Electric Welding Machine

基　　金：辽宁省教育厅2019年度科学研究经费项目(LJJF201902);2018年辽宁装备制造职业技术学院应用性研究专项课题(2018YYYJ-5)。

摘　　要：在自保护堆焊药芯焊丝药粉中加入不同含量的碳化硼(B4C)粉体获得了不同硼(B)元素含量的堆焊层。金相组织观察发现,堆焊层基体为奥氏体和马氏体复合组织结构,晶界处断续分布着(Mo,Cr,Fe,Nb)2B共晶产物,通过固溶强化作用可提高堆焊层的硬度和耐磨性,但存在亚稳定相δ-铁素体,造成堆焊层开裂。经500℃时效处理后,组织中δ-铁素体会转变为σ-铁素体,可有效防止堆焊层开裂,同时提高堆焊层硬度和耐磨性。粉体中碳化硼(B4C)的最佳加入量为1.5%,最高硬度值为47 HRC,相对耐磨性较不加B元素药芯焊丝获得的堆焊层提高3倍。使用该堆焊材料修复的截止阀使用寿命得到延长,同时具有良好的耐腐蚀性,较高的经济价值。The surfacing layers with different boron(B)element content are obtained by adding different amounts of boron carbide(B4C)powder into the self-shield surfacing with flux-cored wire powder.Metallographic observation shows that the matrix of surfacing layer is a composite structure consisting of austenite and martensite,a eutectic component(Mo,Cr,Fe,Nb)2B interruptedly distributes along the grain boundary.The hardness and wear resistance of surfacing layer can be improved by solid solution strengthening effect,but metastable phaseδ-ferrite causes the crack in surfacing layer.After aging treatment at 500℃,the metastableδ-ferrite will transform into theσ-ferrite,which can effectively prevent cracks and improve the hardness and wear resistance of surfacing layer.The optimum addition of boron carbide(B4C)in powder is 1.5%,the maximum hardness is 47 HRC,and the wear resistance is 3 times higher than that of the surfacing layer obtained by flux-cored wire without element B.Using this wire as a surfacing material to repair the stop valve can prolong its service life and has good corrosion resistance and high economic value.

关 键 词：B元素 堆焊 药芯焊丝 组织结构硬度 耐磨性 

分 类 号：TG407[金属学及工艺—焊接]