水口吹氩工艺参数对180mm×700mm板坯结晶器宽面含气率分布的影响

通过建立的6:10几何相似比的模拟180mm×700 mm板坯结晶器的水模型（108 mm×420mm）,使用数字图像处理技术,分析了水量2.54~3.16 m³/h,气量0.037~0.110 m³/h,滑板开口度51%~100%,水口浸入深度78~108 mm等参数对水口吹氩板坯结晶器水模型内宽面含气率分布的影响。结果表明,当水量3.16 m³/h（相当于原型1.50m³/h）,气量0.037 m³/h（原型0.120 m³/h）,水口底部形状为凹形,滑板开口度51%,水口浸入深度78 mm（原型130 mm）时,水模型内气泡分布相对均匀,有利于流场的改善和夹杂的上浮去除。180 mm×700mm铸坯的生产性试验表明,采用优化的参数生产的超低碳钢连铸坯中≥30μm的夹杂物量和夹杂物总量均显著降低。

Effect of Nozzle Argon Blowing Process Parameters on Gas Ratio Distribution at Wide Side of Mold for 180 mm x 700 mm Slab

The effect of process parameters including water rate 2. 54 ~3. 16 m³/h , gas rate 0. 037 ~ 0.110 m³/h, slide gate opening degree (51% ~ 100% ) and nozzle submerged depth 78 ~ 108 mm on gas ratio distribution at wide side of mold for slab casting with nozzle argon blowing has been analyzed by an established 108 mm x 420 mm water model with geometry similarity ratio 6 ：10 to simulate 180 mm x 700 mm mold for slab casting and using digital image process technique. Results show that with water rate- 3. 16 m³/h ( corresponding original type 1. 50 m³/h) , gas rate- 0. 037 m³/h (original type 0. 120 m³/h) , nozzle bottom being concave shape, slide gate opening degree- 51% and submerged depth of nozzle- 78 mm ( original type 130 mm) the distribution of gas bubble is relatively uniform, it is available to improve flow field and inclusions floating off. The results of pilot commercial production of 180 mm x 700 mm cast slab show that the amount of ≥30 μm inclusions and total amount of inclusions in ultra-low carbon steel with using optimizing parameters decrease obviously.