低碳低硅铝镇静钢精炼过程钢中夹杂物行为研究

Study on Inclusion Behavior of Low Carbon and Low Silicon Al-killed Steel During Refining Process

通过对唐钢FTSR冷轧基料(SPHC)钢种整个浇次全程跟踪取样,采用美国ASPEX对所取钢样中夹杂物进行自动扫描检测,分析研究了SPHC钢中非金属夹杂物的主要来源、数量、尺寸分布、组成和类型的演变规律。结果表明:到站喂铝线后夹杂物主要为Al_2O_3,精炼过程中钢液中形成MgO-Al_2O_3系夹杂物。喂铝线夹杂物上浮后,尺寸大于5μm的夹杂物数量为15%;钙处理后,Al_2O_3和Mg O-Al_2O_3系夹杂物变形效果较好,夹杂转变为CaO-CaS-Al_2O_3复合夹杂,尺寸小于5μm的夹杂物大于95%以上。提出了优化造渣、吹氩制度,优化生产组织模式,提高保护浇铸水平等措施,达到了降低夹杂物含量、缩短精炼周期、降低生产成本的目的。

The main source, quantity, size distribution, composition and type evolution rule of non-metallic inclusions in SPHC steel were analyzed and studied through the eastig sampling of Tangsteel FISR cold rolling base material （SPHC） steel,and the inclusions was scanned and detected automatically by ASPEX. The results showed that the inclusions were mainly Al2O3 after feeding aluminum line, and MgO-Al2O3 type inclusions were formed in molten steel during the refining process. The inclusions whose length larger than 5 μm were about 15% after feeding aluminum line and inclusions floatation. After calcium treatment,the Al2O3 and MgO-Al2O3 inclusions had better deformation effect, and the inclusions were changed into CaO- CaS-Al2O3 compound inclusions,the inclusions less than 5 μm were more than 95%. Based on these find- ings, The countermeasure such as optimizing slag-making and argon blowing system, optimizing production organization mode and raising the level of protection casting had been utilized, and achieved the purpose of reducing the inclusion content,shortening refining cycle ,reducing the production cost.