Fe-Cr-C-B-N系堆焊合金的显微组织及耐磨性

在低碳钢表面采用明弧堆焊的方法制备了不同氮含量的Fe-Cr-C-B-N系堆焊合金.借助X射线衍射仪（XRD）、光学显微镜（OM）、扫描电子显微镜（SEM）、洛氏硬度计和湿砂磨损试验机对堆焊层的组织和性能进行分析.结果表明，堆焊层的显微组织为马氏体+奥氏体+BN+M₂₃（C， B）₆+M₃（C， B）+M₂B.随着氮添加量的增多，组织中有BN生成，初生奥氏体向针状马氏体转变，枝晶间共晶组织的数量减少；堆焊层硬度增加，磨损量出现先减少后增加的趋势.当堆焊层中氮的含量为0.17%时，基体组织与硬质相之间匹配良好，堆焊层的综合性能达到最佳，其硬度值为62.7 HRC，而磨损量仅为0.054 2 g.

Microstructure and wear resistance of Fe-Cr-C-B-N hardfacing alloy

On the surface of low carbon steel, the Fe-Cr-C-B-N alloy with different nitrogen content was prepared by the method of arc surfacing. The microstructure and properties of the surfacing layer were analyzed by means of X ray diffraction (XRD), optical microscope (OM), scanning electron microscopy (SEM), Rockwell hardness tester and wet sand wear tester. The results show that the microstructure of the surfacing layer is martensite+austenite+BN+M23 (C, B) 6+M3 (C, B)+M2B. With the increase of the amount of nitrogen, the BN was formed in the tissue, the primary austenite was transformed into acicular martensite, and the number of eutectic structure decreased. The hardness of the hardfacing layer increases, and the wear rate decreases firstly and then increases.When the nitrogen content in the surfacing layer is 0.17%, the matrix structure and the hard phase match well, the overall performance of the surfacing layer is the best, the hardness value is 62.7 HRC, and the wear amount is only 0.054 2g.