Eutectic solidification mode of spheroidal graphite cast iron and graphitization

查看全文 作　　者：Hideo [1]Nakae;Sanghoon [1]Jung;Takayuki [2]Kitazawa 机构地区：[1]Department of Materials Science and Eng., Waseda Univ;[2]Graduate Student, Department of Materials Science and Eng.,Waseda Univ 出　　处：《China Foundry》索引2007年第4卷第1期,共4页 摘　　要：The shrinkage and chilling tendency of spheroidal graphite (abbreviated SG) cast iron is much greater than that of the flake graphite cast iron in spite of its higher amount of C and Si contents. Why? The main reason should be the difference in their graphitization during the eutectic solidification. In this paper, we discuss the difference in the solidification mechanism of both cast irons for solving these problems using unidirectional solidification and the cooling curves of the spheroidal graphite cast iron. The eutectic solidification rate of the SG cast iron is controlled by the diffusion of carbon through the austenite shell, and the final thickness is 1.4 times the radius of the SG, therefore, the reduction of the SG size, namely, the increase in the number, is the main solution of these problems. 关 键 词：球墨铸铁 石墨化 共晶凝固模式 冷却 收缩率