变质处理方式对Cr15高铬铸铁组织和性能影响的研究  

Study on the Effect of Modifying Modes on Microstructures and Mechanical Properties of Cr15 High Chromium Cast Iron

作　　者：石安君 郭长庆[1] 韩继炜 曹国君[1] 

机构地区：[1]江苏大学材料科学与工程学院,江苏镇江212013

出　　处：《铸造》2016年第3期224-227,共4页Foundry

摘　　要：本文介绍了三种不同变质处理方式(即:变质剂炉内加入、出钢槽中加入和铁液包中加入)对Cr15高铬铸铁组织和性能产生影响的差异。采用光学显微镜、扫描电镜观察和分析了高铬铸铁的组织特征;运用XRD分析了高铬铸铁的物相组成;检测了不同变质处理后高铬铸铁的冲击韧度和硬度。试验结果表明:经过变质处理后,Cr15高铬铸铁的初生奥氏体晶粒发生细化,共晶碳化物倾向于由连续网状向断网状的条块转变。钢包内变质效果最为明显,炉内次之,出钢槽变质效果最差。冲击韧度的变化与组织变化相对应。钢包内变质处理冲击韧度达到8.2 J/cm^2,炉内变质处理达到7.8 J/cm^2,出钢槽变质处理达到5.2 J/cm^2,而未变质处理为4.8 J/cm^2;变质处理在使冲击韧度改善的同时也使硬度值略有增加。This paper introduces the effect of three different modifying modes, i.e., the addition of modifying agents into furnace, tapping spout and ladle on the microstructures and mechanical properties of Crl5 high chromium cast irons. The microstructure characteristics of the modified cast irons are observed by optical microscope and scanning electron microscope, and XRD is adopted to analyze the existed phases. The impact toughness and hardness of the cast irons are also tested. The experimental result shows that the primary austenitic grains of the modified Cr15 high chromium cast irons are fined and the eutectic carbides tend to convert from continuous distribution to broken net. More specifically, the best modified results are obtained in the ladle mode, better results in the furnace mode and general results in the tapping spout mode. The impact toughness of the modified high chromium cast irons reaches at 8.2 J/cm^2 for the ladle mode, 7.8 J/cm^2 for the furnace mode and 5.2 J/cm^2 for the tapping spout mode, while only 4.8 J/cm^2 for the non-modification. Thus it can be seen that the hardness and impact toughness of the modified cast irons is remarkably improved by the modification.

关 键 词：高铬铸铁 变质剂 变质方式 显微组织 韧性 

分 类 号：TG250[金属学及工艺—铸造]