V元素对Cr5型热作模具钢回火碳化物的影响

Effect of V on tempered carbides of Cr5-type hot work die steel

采用扫描电镜(SEM)和透射电镜(TEM)研究了V元素对Cr5型热作模具钢回火硬度、显微组织及碳化物的影响。结果表明,V含量高,钢的淬硬性下降,抗回火软化性能增强,对二次硬化峰没有显著影响,同时促进了尺寸为50~100nm的M_(7)C_(3),型碳化物形成。此外,V含量高可使奥氏体化过程中未完全溶入基体的大尺寸MC型富V碳化物保留至回火态。

Effect of V content on tempering hardness,microstructure and carbides of Cr5-type hot work die steel was studied by scanning electron microscope(SEM)and transmission electron microscope(TEM).The results show that high V content reduces the quenching hardness of the steel,enhances its resistance to tempering softening and has no significant effect on the secondary hardening peak.At the same time,it promotes the formation of M_(7)C_(3)type carbides with a size of 50-100 nm.In addition,high V content can make those large-sized MC type V-rich carbides not completely dissolved into the matrix during austenitizing retain to the tempered state.