铌在高铬铸铁堆焊层中的存在状态

The Status of Nb in the High Cr Cast Iron Hardfacing Layer

采用药芯焊丝明弧堆焊的方式形成高铬铸铁堆焊层,通过改变药芯焊丝中添加铌元素的含量,采用扫描电镜对高铬铸铁堆焊层中铌元素的存在状态及数量进行了观察分析,探讨了铌元素对高铬铸铁堆焊层性能的影响。铌在高铬铸铁堆焊层中全部是以碳化铌的形式存在的,碳化铌的数量与含铌量有关。铬及铁元素不进入碳化铌颗粒,铌元素也不进入碳化铬及基体。碳化铌是八面体形式,生长较长时间时呈现树枝状或四角星型。

In this paper, the high Cr cast iron hardfacing layer was prepared by alloy-powder-cored-wire open arc hardfacing. The status of the element Nb and the amount of the NbC in the high Cr cast iron hardfacing layer was observed by using the SEM and adjusting the amount of the Nb. The influence of Nb on the performance of the high Cr cast iron hardfacing layer was studied. All the Nb formed NbC with the C, and the amount of NbC has something to do with the amount of Nb. The element of Cr and Fe does not enter the NbC ,and the Nb does not enter the Cr7C3 and the matrix. The shape of the NbC grain is diamond and four-pointed star.