超低碳钢顶渣氧化性对钢液洁净度的影响

为探究降低顶渣氧化性对改善超低碳钢钢液洁净度的影响,在转炉终点至中间包过程中,在多位置取炉渣和钢水试样,分别进行炉渣氧化性、钢液成分和夹杂物分析.实验结果表明:转炉出钢后通过对顶渣改质,渣中T.Fe由转炉终点的19.18％降至RH进站时的4.68％,顶渣氧化性降低明显.渣中T.Fe降低导致钢中O]的降低,T.Fe较低的炉次平均吹氧量较大,使得铝脱氧前钢中O]较高.RH结束渣T.Fe与夹杂物数量呈线性关系,T.Fe越低夹杂物数量越少,同时RH结束后夹杂物数量与铝脱氧前钢中O]无必然关系.顶渣(CaO)/(Al2O3)会影响其吸收Al2O3夹杂物的能力,(CaO)/(Al2 O3)控制不合理的炉次,其夹杂物数量也较多.通过降低顶渣氧化性,热轧板卷缺陷率得到明显降低.

Influence of ladle slag oxidability on the cleanliness of ultra low carbon steel

Slag oxidability,steel composition and inclusions were analyzed by slag sampling and steel sampling from the BOF endpoint to the tundish for studying the influence of ladle slag oxidability on the cleanliness of ultra low carbon steel.The results show that by ladle slag treatment after BOF tapping,T.Fe content in top slag decreases from 19.18％ to 4.68％ when getting in RH,indicating that the reduction of slag oxidability is obvious.The reduction of T.Fe content in slag leads to the reduction of O] content in steel.For some heats with low T.Fe content,the average oxygen-blowing amount is large,and then the O] content before Al deoxidization is relatively high.The relationship between the T.Fe content of RH end slag and the number of inclusions is linear,but meanwhile there is no obvious relationship between the number of inclusions after RH and the O] content before Al deoxidization.The (CaO)/(Al2O3) ratio of ladle slag influences the Al2O3 absorption ability.The number of inclusions will be large if the (CaO)/ (Al2O3) ratio of the slag is not reasonable.The defects of hot rolled sheets significantly decline with the reduction of slag oxidability.