无渣含铌自保护堆焊药芯焊丝的研制

Development of slag-free self-shielded flux cored wire with niobium addition for hardfacing

摘要: 采用Fe-Cr-Nb-C堆焊合金体系,通过大量试验研制出焊接工艺性能和力学性能良好的无渣含铌自保护药芯焊丝.结果表明,在药芯中不添加任何造渣剂的情况下,药芯中各组分含量(质量分数)锰铁为12%、硅铁为6%、石墨为8%、钛铁为4%且其它组分合适时,自保护药芯焊丝的焊接工艺性能良好;该堆焊层组织由奥氏体、少量马氏体、一次碳化物及共晶物组成,随着铌含量的增加,硬度值先降后增,在铌铁含量3%时,最低硬度值为41.1 HRC.在碳含量有限的条件下,铌在焊接过程中形成碳化物质点,一方面增加了含铌硬质相,另一方面对碳化铬的形成造成影响.

Abstract: Fe-Cr-Nb-C series self-shielded flux-cored wires were developed.The wire exhibits excellent processing performances when it contains 12% Mn-Fe, 6% Si-Fe, 8% graphite and 4% Ti-Fe.The microstructure of the deposited metal is nearly austenite, a small quantity of martensite, primary carbide and eutectic crystal, the hardness changes from 40 HRC to 50 HRC with different niobium contents.When the carbon content is limited, niobium carbide is formed in the welding process, which not only improves the quantity of carbides, but also influences the formation of chromium carbide.