药芯焊丝明弧堆焊Fe-Cr-C-B合金组织及耐磨性

为了提高堆焊合金的耐磨性,利用明弧堆焊方法将自保护耐磨堆焊药芯焊丝熔覆在Q235基体金属表面,制备得到Fe-Cr-C-B耐磨堆焊合金.采用金相显微镜、扫描电子显微镜、X射线衍射仪、硬度计和磨料磨损试验机对堆焊层的组织、硬度和耐磨性进行了分析.结果表明,堆焊层主要由马氏体、少量残余奥氏体、M_3(C,B)、M_(23)(C,B)6和M_7(C,B)3相组成.随着B质量分数的增大,基体组织转变为马氏体,共晶硬质相增多,并呈连续网状分布在基体组织周围.当B的质量分数为3%时,堆焊层的耐磨性达到最佳,其硬度为61. 5 HRC,磨损量为0. 362 9 g.

Microstructure and wear resistance of Fe-Cr-C-B alloy prepared by flux cored wire arc surfacing

In order to improve the wear resistance of surfacing alloy, self-shielded flux cored wire for wear resistance was prepared on the surface of Q235 matrix metal with the open arc surfacing method, and the Fe-Cr-C-B surfacing alloy with wear resistance was prepared. Microstructure, hardness and wear resistance of the surfacing layer were analyzed using metallographic microscope, scanning electron microscope(SEM), X ray diffractometer(XRD), hardness tester and abrasive wear tester. The results show that the surfacing layer is mainly composed of martensite, a small amount of residual austenite, M₃(C, B), M₂₃(C, B)₆ and M₇(C, B)₃ phases. With increasing the mass fraction of B, the matrix structure gradually transforms to martensite, and the amount of eutectic hard phase increases, which is distributed around the matrix with continuous mesh morphologies. When the mass fraction of B is 3%, the wear resistance of surfacing layer is optimum. In addition, the hardness of surfacing layer is 61.5 HRC, and the wear amount is 0.362 9 g.