Abstract: Based on the Taigang 409 L steel casting production process and the parameter of the slab continuous cast¬er machine, influence of submerged nozzle structure on the molten steel flow behavior in the mould and the surface slag entrapment defect of [200 mm x (1060 〜1240 mm) ] casting slab are studied by means of water model experiment and industrial experiment. The results show that the nozzle structure currently in use ( side hole 48 mm x 70 mm, nozzle up dip 15° ) causes severe fluctuation of the liquid lever in mold and heavy entrapment slag on the surface of casting slab. With the condition of no-change nozzle structure, the problem of slag entrapment is impossible to be solved by using nozzle up dip 5° or 10°. The nozzle with side hole size 32 mm x52 mm can effectively solve the slag entrapment on steel409 L surface at small section [200 mm x (900 - 1100 mm) ] or low casting speed (0. 7 ~0. 9 m/min). The nozzle with inner diameter Φ60 mm the average wave height is between 3. 5 mm to 4. 5 mm and entrapment slag decreases from original 36.5% to 0.8% ,the submerged nozzle not only can be applied for present section [200 mm x (900 ~ 1320 mm) ] and casting speed (0.7 ~ 1.1 m/min) but also the casting slab quality can be improved.

摘要： 基于太钢409 L钢连铸生产工艺及板坯连铸机工艺参数,采用水模型实验和工业试验相结合方式研究了浸入式水口结构对结晶器内钢水流动行为及其对连铸坯[200 mm×(1 060～1 240 mm)]表面"卷渣"的影响。结果表明:使用原浸入式水口(侧孔48 mm×70 mm,和上倾15°)结晶器内钢液流场不稳定,对应连铸坯表面存在严重"卷渣"缺陷;在不改变水口结构条件下,上倾5°和上倾10°水口均无法解决连铸坯表面"卷渣";32 mm×52 mm小侧孔水口能有效解决小断面[200 mm×(900～1100 mm)]或低拉速(0.7～0.9 m/min)时409 L钢表面"卷渣";Φ60 mm内径水口对应结晶器中心平均波高在3.5～4.5mm,连铸坯表面"卷渣"缺陷由原来的36.5%降低至0.8%,该型水口不仅能适用现有断面[200 mm×(900～1320 mm)]及拉速(0.7～1.1 m/min)要求,还能提升连铸坯实物质量。