铝连铸连轧过程中铸嘴堵塞的原因与机理  

Cause and Mechanism of Casting Nozzle Clogging During Aluminum Continuous Casting and Rolling

作　　者：沈吉 邓腾飞[1] 姚振华 SHEN Ji;DENG Tengfei;YAO Zhenhua(State Key Laboratory of Silicate Materials for Architectures,Wuhan University of Technology,Wuhan 430070,China;School of Materials Science and Engineering,Wuhan University of Technology,Wuhan 430070,China)

机构地区：[1]武汉理工大学硅酸盐建筑材料国家重点实验室,武汉43007 [2]武汉理工大学材料科学与工程学院,武汉430070

出　　处：《机械工程材料》2020年第2期7-12,17,共7页Materials For Mechanical Engineering

基　　金：国家自然科学基金青年基金资助项目(51801140)。

摘　　要：建立仿真模型模拟了连铸连轧过程中铝液流经铸嘴时的温度场及速度场,试验研究了铸嘴材料与铝液在不同温度(850,900,950℃)反应不同时间(2,4,6,8,10h)后的形貌和成分,分析了铸嘴堵塞的机理。结果表明:在铝液流动过程中,铸嘴在铁板固定处的温度梯度比其他区域的高;铝液流速分布不均匀导致温度分布不均匀,与铸嘴壁接触区域的铝液温度较低,容易发生挂渣;高温铝液与铸嘴材料中的SiO2发生置换反应生成Al2O3夹渣和单质硅,Al2O3的生成会增大铸嘴壁的表面粗糙度,同时会进入铝液使其黏度增大、流速变慢,不能及时冲刷掉铸嘴壁表面挂渣,使得铸嘴壁上的夹渣不断增多,最终导致铸嘴堵塞。The temperature field and velocity field of molten aluminum flowing through the casting nozzle during continuous casting and rolling were simulated by establishing a simulation model.The morphology and composition of the casting nozzle materials after reaction with molten aluminum at different temperatures(850,900,950℃)for different times(2,4,6,8,10 h)were studied by experiments.The mechanism of the casting nozzle clogging was analyzed.The results show that during the molten aluminum flowing,the temperature gradient of the casting nozzle at the fixed position of an iron plate was higher than that of other regions.The uneven velocity distribution of molten aluminum resulted in uneven temperature distribution,and the temperature of the molten aluminum in contact with the nozzle wall was relatively low,which led to slag hanging easily.Al2O3 slag inclusions and silicon were formed by displacement reaction of high temperature molten aluminum with SiO2 in the nozzle materials.The produced Al2O3 would increase the surface roughness of the nozzle wall,and also it would enter the molten aluminum to increase the viscosity and slow down the flow velocity;therefore the slag inclusions on the nozzle wall could not be washed away in time.The slag inclusions on the nozzle wall then continued to increase,and eventually caused the nozzle clogging.

关 键 词：铝液 连铸连轧 铸嘴堵塞 有限元模拟 

分 类 号：TG249.3[金属学及工艺—铸造]