双辊铸轧工艺参数对熔池场变量的影响

Influence of parameters on molten pool field during twin-roll casting process

双辊铸轧过程控制是一个高度复杂的工程问题,熔池流场和温度场的稳定性直接影响着带坯的质量。研究铸轧工艺参数对流场、温度场的影响规律,对于得到厚度均匀的板带具有重要意义。基于立式双辊铸轧工艺构建了1∶1水模型实验平台和标准湍流数学模型,研究了铸轧速度、熔池接触角及浇注温度对熔池流场、液面波动及出口温度的影响。结果表明:在熔池出口附近,由于熔池体积减小而产生液体回流现象,且回流区域面积与铸轧速度近似成正比。铸轧速度越大,出口温度越高,沿板宽方向温差越小。当铸轧速度大于7.2m/min或熔池接触角小于40°时,熔池液面波动过于剧烈,会严重影响板带的质量。

Controlling of twin-roll strip casting process is a highly complex engineering problem.The quality of the strip depends on the stability of flow and temperature fields.The effect of casting process parameters on the flow and temperature fields is of great importance on the products quality.Based on the vertical twin-roll strip casting,a water model experiment platform with scale of 1∶1was built.And a standard turbulence mathematic model was developed considering the influence of the rotation of casting roll on the flow field of the pool,then the influence of casting speed,pool contact angle and pouring temperature on surface fluctuations and outlet temperature of the pool was studied.The results show that the back flow occurres near the outlet of the molten pool because the pool volume decreases sharply.The backflow area is approximately proportional to the casting speed.With increasing the casting speed,the pool′s outlet temperature increases and the temperature difference of the strip width decreases.The molten pool surface fluctuates seriously when the roll casting speed is greater than 7.2m/min or pool contact angle is less than 40°,which seriously affects the quality of the strip.