不锈钢方坯连铸结晶器内钢渣界面行为的数值模拟研究

Numerical simulation research on steel-slag interface behavior in the continuous casting mold for stainless steel billet

不锈钢方坯生产初期由于卷入保护渣而导致连铸坯内部出现大颗粒夹杂物,影响产品质量。卷渣与钢渣界面行为有较大关系,因此通过Fluent软件对不锈钢方坯浸入式水口在不同插入深度下的结晶器内钢液流场、钢渣界面行为进行了数值模拟。模拟结果显示:水口插入深度小于110 mm时,钢渣界面被严重破坏,结晶器保护渣会卷入钢液;水口插入深度大于130 mm时,钢渣界面处钢液速度过小,附近钢液的质量和热量更新速度慢,从而导致其温度较低,不利于保护渣均匀熔化。综合考虑后,现场生产时结晶器浸入式水口插入深度确定为(120±5)mm,显著提高了不锈钢方坯质量。

There are some inclusions with big size which is originated from slag entrapment in mold at the early stage of stainless steel billet production,and which seriously affects the quality of products. The slag entrapment is related with the steel-slag interface behavior,therefore,the fluid field and interface behavior of steel slag in the mold for stainless steel billet under the condition of different immersion depths of SEN was numerically studied. The results show that when the immersion depth of SEN is below 110 mm,the steel- slag interface can be broken,and the slag can be entrapped into steel. When the immersion depth of SEN is over 130 mm,the velocity of steel at the steel-slag interface is so small that the mass conversion of steel is not enough,which is not beneficial to melt the slag uniformly. Finally,the immersion depth of SEN is adjusted to（120±5） mm in production,and the quality of stainless steel billet is improved greatly.