过共晶高碳Fe-B-C钢的组织与耐磨性能研究

摘要

系统研究了稀土变质和热处理工艺对过共晶高碳Fe-B-C钢组织和性能的影响.研究发现,稀土变质对初生硼化物具有显著的细化效果,随着稀土变质剂的增加,初生硼化物尺寸越来越小,共晶硼化物的形状也由菊花状向颗粒状转变.稀土加入量为0.6%时可以取得最佳的综合变质效果.铸态硼化物Fe,(C,B)相970℃油淬处理后部分分解为Fe3B 相;1050℃热处理后,硼化物相则全部转变为Fe2B相.高碳高硼耐磨合金经过稀土变质与热处理后具有良好的耐磨性与性价比,是替代高铬铸铁的理想新型合金.%The influence of RE modifier and heat treatment on microstructure and properties of the hypereutectic high carbon Fe-C-B steel was investigated. The results show that the solidified microstructure of the hypereutectic high carbon Fe-C-B steel is composed of the α-Fe phase, primary Fe2B phase and eutectic Fe3( C,B) phase. The primary Fe2B phases are visibly refined after modified with RE element. With the increasing of RE addition, the size of the primary Fe2B phases is decreased.Meanwhile, the morphologies of the eutectic boride are changed from rosette-shaped to the graininess.After heat treatment, the eutectic boride changes substantively. Some of the eutectic Fe3(C,B)phases transformed to Fe3B phases after 970 ℃ oil quenching. However, after the 1 050 ℃ oil quenching, all of the eutectic Fe3( C, B) phases are disappeared and transformed to Fe2B phases. The hypereutectic high carbon Fe-C-B steel shows excellent mechanical properties after RE modification and heat treatment, and the wear resistance is corresponding to the high chromium cast iron.