凝固坯壳对高拉速板坯连铸结晶器液面特征的影响  

Effect of solidified shell on level characteristics in continuous casting slab molds for high speed casting

作　　者：邓小旋[1] 黄琦[2] 王新华[2] 李林平[2] 季晨曦[1] 朱国森[1] 

机构地区：[1]首钢技术研究院,北京100043 [2]北京科技大学冶金与生态工程学院,北京100083

出　　处：《北京科技大学学报》2014年第9期1247-1254,共8页Journal of University of Science and Technology Beijing

摘　　要：采用1:1的水模型研究了高拉速条件下凝固坯壳对结晶器内的流场与液面特征的影响.结果表明:考虑凝固坯壳时结晶器内的流场出现了轻微的不对称现象,在高拉速条件下(2.4m·min^(-1)),有坯壳时结晶器液面最大平均波高与表面流速比没有坯壳时分别大31%和35%.对比有/无坯壳条件下自由液面形状可知:考虑凝固坯壳之后的液面变形程度比没有考虑时更大,更易导致卷渣的发生.液面波动的功傅里叶变换分析表明:考虑坯壳之后结晶器液面的高频率波动的振幅大于无坯壳的情形,所以考虑坯壳之后由于结晶器下部内腔变小,更多的流股能量集中在上回流区,使得上回流的湍流程度比无坯壳时要大,进而导致了液面波动与表面流速的增大.因此,为了缩小与实际连铸过程的差别,在高拉速的物理模拟中有必要考虑凝固坯壳的影响.A full scale water model of continuous casting was built to investigate the effect of solidified shell on fluid flow and level characteristics under high speed casting. It is found that a slight asymmetry of fluid flow occurs in the model with solidified shell. Fur-thermore, the average level fluctuation and the meniscus velocity of the mold with solidified shell is 31% and 35% larger than those without solidified shell at a high casting speed of 2. 4 m·min - 1 , respectively. The deformation of the top level profile of the mold with solidified shell is also larger than that without solidified shell, which can be vulnerable to slag entrapment. In addition, the fast Fourier transformation analysis of level oscillation shows that the amplitude of high frequency fluctuation in the mold with solidified shell is lar-ger than that without solidified shell due to a narrower space in the lower part of the mold, indicating that a more turbulence energy ex-ists in the upper recirculation zone than that without solidified shell and thus results in a higher level fluctuation and a larger surface ve-locity. So taking solidified shell into consideration is necessary to minimize the difference between the model and actual steel casters.

关 键 词：连铸 结晶器 凝固坯壳 水模拟 高速 

分 类 号：TF777.1[冶金工程—钢铁冶金]