碳含量及复合变质处理对白口铸铁组织和性能的影响  

Influence of Carbon Content and Complex Modification on Microstructure and Mechanical Properties of White Cast Iron

作　　者：王伟[1] 肖于德[1] 林家平[1] 徐建秋[1] 杨迎春 董铁铭 邓培成 

机构地区：[1]中南大学材料科学与工程学院,长沙410083 [2]湖南株洲湘能特钢有限公司,株洲412003

出　　处：《机械工程材料》2009年第9期64-67,共4页Materials For Mechanical Engineering

摘　　要：通过在铸造过程中对熔体进行复合变质处理，制备了变质白口铸铁，采用金相分析、碳化物定量分析、硬度测试和冲击韧度测试等研究了碳含量（2．2％～3．2％）及复合变质处理对白口铸铁组织和性能的影响，并研究了碳含量对复合变质效果的影响。结果表明：随着碳含量的增加，白口铸铁的显微组织由珠光体＋离异共晶状渗碳体向少量珠光体＋大块连续的莱氏体转变；通过复合变质处理可以有效改善碳化物的形态与分布，碳化物变得孤立、分散，部分网状结构消失，但随着碳含量的提高，复合变质效果变差；经过变质处理后，白口铸铁的硬度和冲击韧度都有所提高。White cast iron was prepared by melt-complex modification method during the process of casting. The influences of complex modification and carbon content （2. 2%- 3. 2%） on microstructure and mechanical properties, and the effect of carbon content on the modification effect were investigated by using optical microscopy, quantitative carbide analysis, hardness test and impact toughness test. The results show that with increasing the carbon content, the microstructure of the white east iron transformed from divorced eutectic cementite plus pearlite to pearlite plus bulk ledeburite, Additionally, complex modification could improve the morphology and distribution of carbide significantly. The carbide net was partly dismissed after complex modification. However, with the increase of carbon content, the effect of the complex modification declined. The hardness and impact toughness both increased after modification.

关 键 词：白口铸铁 变质处理 显微组织 碳含量 

分 类 号：TG143.3[一般工业技术—材料科学与工程]