钢包顶渣改质对IF钢夹杂物的影响

Influence of slag denaturalization on inclusions in IF steel

为减少连铸絮流和降低钢中夹杂物含量,国内某厂在转炉→氩站→RH→板坯连铸工艺流程生产IF钢时引入钢包顶渣改质技术并开展了钢包顶渣改质试验。为考察钢包顶渣改质技术的使用效果,利用桶状取样器获取RH精炼终点、中间包的钢水试样并取对应的连铸坯试样,采用ASPEX Explore型自动扫描电镜对比分析了改质和不改质工艺条件下RH→中包→铸坯的夹杂物数量、类型、尺寸。研究结果表明:钢包顶渣改质能有效降低炉渣氧化性、改善钢水洁净度;2种工艺条件下的夹杂物主要类型为Al_2O_3,TiO_x-Al_2O_3和Oxides,不改质工艺中的Oxides类型夹杂物的比例明显高于改质工艺;改质工艺中的铸坯簇状夹杂物类型单一,数量和尺寸较小,优于不改质工艺。

In order to reduce the flocculating flow or clogging of continuous casting and the content of inclusions in steel,a new technology of ladle top slag denaturalization was introduced in the production of IF steel with the process of＂BOF→Argon station→RH→CC＂at one company.To examine the effect of the use of the ladle slag modification technology,trial research on slag denaturalization was also carried.Molten steel samples were taken from RH refining end-point and tundish by using the barrel sampler.The corresponding slab samples were also taken.Inclusions were tested by using ASPEX Explore automatic Scanning Electron Microscopy（SEM）.Contrast analysis of the quantity,type and size of the inclusions of RH→tundish→slab were carried on under the condition of denaturalization and non-denaturalization process.The results show that slag denaturalization effectively reduce slag oxidizability,improving steel cleanliness;the main types of inclusions under both process conditions are Al_2O_3,TiO_x-Al_2O_3 and oxides.The proportion of oxides inclusions with denaturalization process is significantly higher than non-modification process;clusters of inclusion types in slab with the process of modification are single and the quantity and size are smaller than non-modification process.