镁在球铁液冷却过程中的运动分析  

Motion Analysis of Mg in Cooling Process of Ductile Iron

作　　者：孙少东[1] 何时剑[1] 张孟群[2] 刘笛[2] 

机构地区：[1]淮安信息技术学院机电工程系,江苏淮安223001 [2]南京大学材料分析中心,江苏南京210018

出　　处：《热加工工艺》2010年第15期53-55,共3页Hot Working Technology

摘　　要：通过对球墨铸铁件表皮及横截面上含镁量的测定,发现球铁铸件不同方向的表面上镁的含量相同,且明显地高于平均成分;从铸件表面到心部的横截面上镁的含量不相同,呈现梯度增加的分布状态。在依据气泡上浮理论或成分偏析理论都不能解释这一实验结果的情况下,提出了石墨化膨胀促进气泡迁移的观点,并且分析了整个冷却过程中气泡迁移的路径和速度。Testing Mg content in the surface and the cross section of a ductile iron casting show that Mg content is identical in different directional surfaces,and they are all significantly higher than the average content in the casting,and the Mg content from the surface to the center of the casting presents gradient rising.Based on the theory of bubbles floating or composition segregation,the experimental results can not be explained,so,a view is proposed that the expansion of spherical graphite in the molten metal promotes the migration of the bubbles,and the path and velocity of bubble migration is also discussed.

关 键 词：球墨铸铁 石墨膨胀 氧化结膜 气泡迁移 

分 类 号：TG143.5[一般工业技术—材料科学与工程] TG245[金属学及工艺—金属材料]