B元素对Cr-Ni-Mo-Mn系药芯焊丝堆焊金属组织结构的影响

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 裘荣鹏 QIU Rongpeng 1 first-author 辽宁装备制造职业技术学院 辽宁装备制造职业技术学院 Liaoning Equipment Manufacturing Vocational and Technical College Liaoning Equipment Manufacturing Vocational and Technical College 在自保护堆焊药芯焊丝药粉中加入不同含量的碳化硼（B 4 C）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（B 4 C）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（B4 C） 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）2 B interruptedly distributes along the grain boundary. The hardness and wear resistance of surfacing layer can be improved by solid solution strengthening effect,but metastable phase δ-ferrite causes the crack in surfacing layer. After aging treatment at 500 ℃,the metastable δ-ferrite will transform into the σ-ferrite,which can effectively prevent cracks and improve the hardness and wear resistance of surfacing layer. The optimum addition of boron carbide（B4 C） 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. B元素 堆焊 药芯焊丝 组织结构硬度 耐磨性 TG455 辽宁省教育厅2019年度科学研究经费项目(LJJF201902) 2022-03-08 8 50