高碳钢小方坯的一次枝晶臂间距的影响因素  

Influential factors of primary dendritic arm spacing in high-carbon steel billets

作　　者：冯军[1] 陈伟庆[1] 

机构地区：[1]北京科技大学冶金与生态工程学院,北京100083

出　　处：《北京科技大学学报》2007年第1期25-29,共5页Journal of University of Science and Technology Beijing

摘　　要：高碳钢小方坯显微凝固组织的研究表明:一次枝晶臂在凝固过程中不断粗化变短;碳含量高,容易形成长宽比小的一次枝晶,并且一次枝晶臂间距增宽,容易形成粗大的柱状晶组织;过热度高,易形成粗大的一次枝晶,一次枝晶臂间距增宽;拉速慢,容易形成细长的一次枝晶,一次枝晶臂间距减少;二次冷却水流量比增加,易形成细长的一次枝晶,一次枝晶臂间距降低.结晶器电磁搅拌可显著降低一次枝晶臂长宽比,并减小一次枝晶臂间距;搅拌电流增加,则一次枝晶臂间距减小效果更明显.The microstructure during solidification of high-carbon steel billets was investigated, The results showed that primary dendritic arms in the billets were becoming coarser and shorter with evolvement of solidification. A higher carbon content in the steel was favorable to form short and thick primary dendrites as well as wider primary dendritic arm spacings （PDAS） and coarsening columnar structure. A higher superheat promoted coarse primary dendrites and wider PDAS. With the withdrawal rate slower, it was easy to form narrow PDAS. The greater the secondary cooling water flow ratio, the easier the spindly primary dendrites and narrow PDAS formed. Mole-electromagnetic stirring （M-EMS） greatly reduced the PDAS and dendritic length-to-width ratio. With the increase of M-EMS electric current, the PDAS was reduced obviously.

关 键 词：高碳钢 小方坯 连铸 枝晶臂间距 凝固组织 

分 类 号：TF777.3[冶金工程—钢铁冶金] TG244.3[金属学及工艺—铸造]