CO_2气体保护药芯焊丝喷粉-堆焊层组织及其耐磨性

Microstructure and Wear Resistance of Surfacing Layer Shielded by CO_2 with Spraying Powder

采用CO2气体保护焊方法,使用高铬铸铁药芯焊丝,喷射优化设计的Cr-Ti-Mn-B系粉体形成耐磨堆焊层。利用XRD及金相显微镜分析堆焊层组织结构,并测定堆焊层的硬度和磨损性能。结果表明:与单纯高铬铸铁芯堆焊层相比,喷射粉体后堆焊层的洛氏硬度HRC增加,当Mn铁、Cr铁、B铁、Ti铁质量分数比为4.3∶52.2∶3.9∶39.6时,堆焊层硬度和耐磨性最高。喷射粉体堆焊层以马氏体为主,并有(Cr,Fe)7C3,FeMn2等相产生,从而提高堆焊层硬度和耐磨性。

Surfacing welding layer composed of spraying optimized Cr-Ti-Mn-B powder was fabricated by CO2 shielded welding with high ferrochrome flux-cored wire.The structure was characterized by XRD and metallographic microscope.The hardness and wear resistance of surfacing welding layer were tested.The results indicats that HRC of the surfacing welding layer with the powder increases compared with that of single surfacing layer welded by high ferrochrome flux-cored wire.The hardness and wear resistance of the sample composed with the powder of 52.2% Cr,39.6% Ti,4.3% Mn and 3.9% B is the best.The main microstructure of the surfacing welding layer powder is martensite,with（Cr,Fe）7C3 and FeMn2 phases detected,which enhance the hardness and wear resistance of surfacing welding layer.