采用药芯焊丝自保护明孤堆焊方法制备了系列高铬合金,借助光学显微镜、X射线衍射仪、扫描电镜及湿砂耐磨性实验,研究了SiC含量对其性能的影响.结果表明,SiC显著影响其显微组织形态、尺寸、数量及分布.当SiC含量0％～4％(质量分数,下同)时,堆焊层维织晶粒细化,共晶组织(a-Fe+ M3 (C,B))数量增加,耐磨性下降；当其含量增加到8％时,堆焊层组织形成初生M23C6碳化物而改善耐磨性；但当SiC加入量大于12％时,SiC分解出过量的硅原子反而会使焊缝的石墨化倾向增加,抑制初生M23C6碳化物形成,致使耐磨性下降.磨损形貌分析表明,随SiC增加,其磨损方式从凿削为主转变为刮伤与凿削两种方式共存.%A series of high chromium alloys were prepared by the method of self-shielded open arc flux-cored wire hardfacing with varying SiC content. The effect of SiC on the properties was investigated by optical microscopy (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM) and wet sand rubber wear tests. The results show that SiC has a significant effect on the shape, the size, the volume fraction and the distribution of the microstructure. With the addition of 0%-4% (mass fraction, the same below) SiC into a flux-core wire, the grains were refined and the volume fraction of the eutectic (α-Fe+M3(C,B)) increased, which made abrasion resistance descended. As SiC content rose up to 8%, the primary M23C6 grains appeared and the abrasion resistance was improved. But when it was higher than 12%,excessive Si atoms provided by the decomposition of SiC can inversely intensify the graphitization tendency of weld beads, which inhibited the formation of primary M23C6 phases. The analysis of worn morphology indicates that the wear mode of material removal changes from the dominant clipping to the combined scoring and clipping with the increasing addition of SiC powders.
展开▼
