Abstract: The mold liquid surface fluctuation, impact depth, distribution of flow field and powder covering condition with using original submerged nozzle (lower hole diameter 78 mm, side hole long axis 80 mm and short axis 66 mm) and with using optimized submerged nozzle of reduced hole dimension (lower hole diameter 65 mm, side hole long axis 75 mm and short axis 60 mm) for mold of 230 mm x 1 250 mm casting slab have been studied by using geometric similarity 1: 2 water model. Results show that in same working procedure condition with using optimized submerged nozzle the liquid surface fluctuation is more active, the thickness liquid slag layer is relative uniform, i. e. reducing side hole area of nozzle is available to increase the velocity of flow at outlet and favorable to melt the mold powder. By measured the thickness of liquid slag layer in mold for casting 230 mm x 1 250 mm slab of steel DP600 at steelworks the results show that with nozzle submerged depth 130 mm and steel flow rate 2. 8 t/min, by using the original nozzle the liquid surface in mold is less active and the difference of thickness of liquid slag layer in mold is 12 ~ 13 mm, but the liquid surface in mold is rather active and the difference of thickness of liquid slag layer is 3 〜5 mm by using optimized nozzle.

摘要： 采用几何相似比1:2水模型研究了230 mm×1 250 mm板坯结晶器原浸入式水口（下孔直径78 mm,侧孔长轴80 mm,短轴66 mm）和缩小孔面积的优化水口（下孔直径65 mm,侧孔长轴75 mm,短轴60 mm）结晶器液面波动、冲击深度,流场分布和保护渣覆盖情况。结果表明,同种工况下,优化水口下液面波动更活跃,液渣层相对均匀,即减小水口侧孔面积,能提高流股出口速度,有利于保护渣熔化;钢厂生产DP600钢230 mm×1 250 mm铸坯测定结晶器内液渣层的厚度表明,当水口浸入深度130 mm,通钢量2.8 t/min时,使用原有水口时液面不太活跃,液渣层厚度差为1213 mm,使用优化水口时,液面较活跃,液渣层厚度差为35 mm。