(燕山大学国家冷轧板带装备及工艺工程技术研究中心，秦皇岛 066004)
摘 要: 以薄带铸轧中心线偏析问题为研究对象，从宏观和微观角度分析铸轧薄带芯部偏析的成因与机理，建立完全耦合溶质场、流场、温度场的数学模型。通过数学模型对铸轧铝合金熔池中的Fe、Mn元素分布进行研究。结果表明：理论研究与实验结果基本吻合。熔池区凝固组织以柱状晶形式沿á001？方向迅速生长，同时溶质成分逐渐偏聚于熔池芯部区域，并在Kiss点区域达到最大值。其中Fe元素在Kiss点区域的含量明显高于其他区域的，完全凝固后易产生中心线偏析。随着铸轧速度的提高，辊缝宽度增大，中心线偏析趋势增强。
关键字: 双辊薄带铸轧；溶质场；流场；中心线偏析；Kiss点
（National Engineering Research Center for Equipment and Technology of Cold Strip Rolling,
Yanshan University, Qinhuangdao 066004, China）
Abstract:The problem of casting Al-alloy strip was studied, the mechanism of as-cast strip centerline segregation was analyzed from the perspective of macro and micro, and a mathematical method was developed which completely couples solute field, flow field and temperature distribution. The distributions of Fe and Mn in the Al alloy molten pool were figured out by the mathematical method. The results show that the theoretical calculation agrees well with the experimental results. The solidification structure growsalongá001？ direction rapidly by the form of columnar crystal. Meanwhile, the solute elements are focused gradually in the kern zone, and the maximum value is gotten at the Kiss point zone. In particular, Fe content of the Kiss point zone is much higher than the average value, and centerline segregation appears after solidification. The centerline segregation tends to increase with the increase of casting speed and roll gap.
Key words: twin-roll strip casting; solute field; flow field; centerline segregation; Kiss point
