钨铬合金白口铸铁中碳化物三维形貌及结晶特征

通过观察分析钨铬铸铁中碳化物的三维形貌,研究了M_3C、M_7C_3、M_6C三种碳化物的结晶特征。初生M_3C以平板状生长;亚共品、过共晶铸铁中共晶M_3C分别以初生奥氏体、初生M_3C为衬底与奥氏体构成离异共晶和莱氏体。初生M_7C_3呈六角形棒状体以螺旋方式轴向生长的同时向心生长;共晶M_7C_3与奥氏体协同生长。初生M_6C为八面体尖端相连的枝晶形态呈“锚状”生长。

Three Dimensional Morphology and Crystal Characteristics of the Carbides in Tungsten-Chromium Alloyed White Iron

By observing and analyzing the three-dimensional morphology of the three kinds of carbides (M_3C, M_7C_3, M_6C)in Tungsten-Chromium cast iron, the crystal characteristics of the carbides were studied. The results show that the primary carbide M_3C grows flatly. The eutectic carbide M_3C in the hypoeutectic or hypereuteetic cast iron grows on the base of the primary austenite or primary carbide M_3C respectively, and forms the segregated eutectic and ledeburite together with austinite, the primary carbide M_7C_3 grows spirally on both the axle and radial direction, and forms a hexagonal bar. The cutectic carbide M_7C_3 grows synergetically with aastenite. The primary carbide M_oC grows into octahedron dendrites whose tip are connected and looks like an anc(?)or.