铌对高铬铸铁堆焊层耐磨性的影响

Influence of Nb on wear resistance of surfacing metal of high Cr cast iron

采用药芯焊丝堆焊的方式，以碳含量5％～6％和铬含量22％左右的高铬铸铁为基础，通过调整焊丝中铌的加入量，探讨了不加铌元素和添加6％的铌元素时，铌对耐磨性能的影响机理。铌在高铬铸铁中全部以碳化铌的形式存在，与碳化铬互不相溶。通过加入6％的铌，耐磨性能提高了16．9％。碳化铌的数量与铌的加入量有关。碳化铌形状为菱形。

The mechanism of the influence of Nb on wear resistance by surfacing of flux-cored wire with 6% and without Nb on high Cr cast iron with 5% -6% C and 22% Cr was studied. The existing form of Nb in surfacing metal of high Cr cast iron is NbC, which can not dissolve each other with Cr7C3. The wear resistance can be increased 16.9% when 6% Nb was added into flux-cored wire. The amount of NbC depends on the adding amount of Nb. The shape of the NbC grain is diamond.