交换钢包过程对IF钢连铸板坯表层洁净度的影响  

Effect of ladle change process on the surface cleanliness of IF steel continuous casting slabs

作　　者：邓小旋[1,2] 王新华[1] 李林平[1] 魏鹏远[1] 季晨曦[2] 曾智[2] 田志红 

机构地区：[1]北京科技大学冶金与生态工程学院,北京100083 [2]首钢技术研究院,北京100043 [3]首钢京唐公司炼钢部,唐山063200

出　　处：《北京科技大学学报》2014年第7期880-886,共7页Journal of University of Science and Technology Beijing

基　　金：国家重点基础研究发展计划资助项目(2010CB30806)

摘　　要：采用ASPEX扫描电镜中的自动特征分析功能研究了交换钢包过程(取样浇次第4、5炉)对IF钢连铸板坯表层的洁净度的影响,且对比研究了交换钢包过程浇铸铸坯(交接坯)与正常浇铸铸坯(正常坯)的表层洁净度.结果表明:正常坯与交接坯中尺寸大于20μm的表层夹杂物可分为三类:(1)簇群状Al2O3(包括气泡+簇群状Al2O3);(2)簇群状TiOx--Al2O3夹杂物;(3)保护渣夹杂物.正常坯表层的大型夹杂物主要为簇群状Al2O3,没有检测到保护渣夹杂物.换包开浇后铸坯总氧质量分数从14×10-6增至17×10-6,交接坯表层检测到较多的第2夹杂物,说明钢包开浇后钢水被轻微氧化.此外,钢包开浇后剧烈的液面波动也导致了保护渣的卷入.在当前工艺下,换包对IF钢铸坯表层洁净度的影响长度约为11m.The effect of ladle change process （the 4th heat to the 5th heat） on the surface cleanliness of IF steel continuous casting slabs was investigated by total oxygen measurement and automatic feature analysis equipped on ASPEX. A comparison of surface cleanliness was performed between transition slabs （ cast during ladle change process ） and normal slabs （ cast under normal condition）. It is found that inclusions larger than 20μm are classified into three types：（1） cluster alumina （including bubble ＋ cluster a-lumina inclusions）;（2） cluster TiOx-Al2O3 inclusions; and （3） mold powder inclusions. In terms of surface inclusions in normal slabs, most of the inclusions detected in the scanning area are cluster alumina, and no mold powder inclusions are found. While for transition slabs, the total oxygen content increases from 14×10^-6 to 17×10^-6 , and the number density of Type 2 inclusions goes up since the cast start of the 5th heat, indicating re-oxidation of the steel melt during ladle change process. Furthermore, level fluctuation in the mold is also severe since the cast start of the 5th heat, leading to mold powder entrapments. The affected length of cast slabs during ladle change process is about 11 m under the present casting condition.

关 键 词：IF钢 连铸 铸坯 表面 洁净度 夹杂物 氧化铝 

分 类 号：TF777.1[冶金工程—钢铁冶金]