拉速对板坯倒角结晶器钢液流动的影响

为研究凝固坯壳影响时拉速变化对板坯倒角结晶器内流场和温度场的影响,通过数值模拟和物理模拟研究相结合的方法,建立了板坯倒角结晶器流动、传热及凝固三维数学模型和相似比为1∶1的断面尺寸为1 490 mm×230 mm的板坯倒角结晶器物理模型。数值模拟和物理模拟流场形态及液面相同位置流速结果进行的对比分析表明了数模和水模试验结果趋势的一致性;拉速变化对倒角结晶器内流场及温度场的数值影响明显,但对整体形态影响不大;拉速增大到1.7 m/min时液面流速过快、波动剧烈,极易出现卷渣;拉速增大会强化钢液流股对窄面凝固坯壳的冲击,导致坯壳重熔减薄;在本试验研究范围内以1.5 m/min拉速进行生产能够取得较好的综合效果。

Effect of casting speed on molten steel flow in slab chamfered mould

In order to study the casting speed on the condition of solidified slab shell has effects on the flow and heat transfer in the slab chamfered mould, a three-dimensional mathematical model of flow, heat transfer and solidification of slab chamfered mould and a physical model of slab chamfered mould with section size of 1 490 mm×230 mm and similarity ratio of 1∶1 were established by combining numerical simulation and physical simulation. The comparison between numerical simulation and physical simulation of flow field morphology and flow velocity at the same position of liquid surface shows that the trend of numerical simulation and water simulation is consistent. Casting speed has obvious effect on the numerical value of the flow field and temperature field in the chamfered mould, but has little effect on the overall shape. when the casting speed is increased to 1.7 m/min, the liquid surface velocity is too fast and fluctuates sharply, and slag entrapment is easy to occur.With the increase of casting speed, the impact of molten steel stream on the narrow surface solidified billet shell will be strengthened, resulting in remelting and thinning of the billet shell.Within the scope of this experiment, a better comprehensive effect can be achieved by producing at a casting speed of 1.5 m/min.