低碳铝镇静钢中间包浇注过程夹杂物的行为  

Inclusion Behavior of LCAK Steel in Tundish Pouring Process

作　　者：殷雪[1] 孙赛阳[1] 孙彦辉[1] 赵勇[1] 葛亮[1] 张西超[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：《钢铁》2014年第8期21-26,共6页Iron and Steel

摘　　要：通过对BOF-Ar站-CC炼钢流程生产低碳铝镇静钢的中间包不同浇注时间取样及正常坯的取样,采用氧氮化学分析、光学显微镜以及扫描电镜-能谱（SEM＋EDS）等多种方法研究了中间包浇注过程夹杂物特征的变化。结果表明：每炉钢包开浇时与浇注末期,钢中T[O]含量均高于浇注中期的T[O]含量,这是由于换包过程中钢水被二次氧化;中间包钢水及正常坯中的夹杂物,按照其形貌与成分可以分为以下3类：Al2O3基夹杂物,MnS基夹杂物,来自中间包覆盖剂或者钢包下渣所卷入的外来夹杂物。中间包及铸坯中的夹杂物主要以1~4μm的Al2O3为主,同时在铸坯中发现了大量的MnS夹杂物,使铸坯中夹杂物的数量密度升高。当钢液中硫含量较高时,铸坯中气泡＋Al2O3类型的夹杂物增加。在当前的工艺条件下,交换钢包之后的开浇阶段与浇注末期,钢水的二次氧化对铸坯的洁净度产生重要影响,同时应合理控制钢中的硫含量,减少铸坯中气泡＋Al2O3类型的夹杂物,避免钢液在凝固过程中析出大量的MnS夹杂物。The variations of inclusion characteristic of LCAK in tundish and normal slabs produced by BOF-Ar station- CC processes were studied by systematically sampling in different pouring time and nomal slabs of steel production. Anal- ysis methods mainly include total oxygen and nitrogen content analysis, optical microscopy, scanning electronic microscope （SEM）, and energy dispersive X-ray spectroscopy （EDS）. The results show that： Total oxygen content at the starting and end of ladle pouring is higher than the middle pouring, which indicate that there exists re-oxidation during ladle change practice. The inclusions in tundish and normal slabs are classified into three types according to their morphology and composition： alumina inclusions; MnS inclusions; tundish flux inclusions or ladle slag inclusions. Inclusions of tundish and slab mainly contain Al2O3 inclusions with the size of 1-4 μm,also there are lots of MnS inclusions in the slab result in the rising of the number density. The number of bubble＋alumina inclusions increases on steel of higher sulphur content. To sum up, at the stage of starting and end of pouting after the exchange of ladle, re-oxidation is the main reason which restrain the quality of the slab.Meanwhile, the sulfur content in steel should be controlled in a certain range in order to decrease the bubble＋alumina inclusions and also avoid the precipitation of MnS inclusions during the solidification process.

关 键 词：中间包 铸坯 夹杂物类型 AL2O3 

分 类 号：TF771[冶金工程—钢铁冶金]