研究不同的含铌量对4%C-20%Cr(质量分数,下同)过共晶高铬铸铁显微组织的影响。结果表明,随着含铌量的增加,初生碳化物逐渐细化。Nb细化过共晶高铬铸铁的机制可解释为:弥散分布的NbC可能作为初生碳化物的异质形核质点;NbC颗粒阻碍初生碳化物的长大;生成NbC的反应消耗一部分C而降低过共晶高铬铸铁的过共晶程度。 The effect of different niobium content on the microstructure of hypereutectic high chromium cast iron with 4% C-20% Cr (mass fraction) was investigated. The results show that, with the increase of niobium content, primary carbides gradually refine. Nb refinement of hypereutectic high chromium cast iron mechanism can be interpreted as: dispersed NbC may act as heterogeneous nucleation sites of primary carbides; NbC particles impede the growth of primary carbides; the reaction of generating NbC consumes a portion of C and decreases Hypereutectic hypereutectic high chromium cast iron degree.