Cause and Mechanism of Casting Nozzle Clogging During Aluminum Continuous Casting and Rolling
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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（2，4，6，8，10 h）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。Abstract: 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.
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[1] 彭开香,童朝南,董洁,等.1400 m铝带箔冷轧机板形控制系统[J].冶金自动化,2004,28(4):32-35. [2] 旷亚非, 许岩, 李国希. 铝及其合金材料表面处理研究进展[J]. 电镀与精饰, 2000, 22(1):16-20. [3] 关绍康. 铝合金板带连铸连轧节能新工艺关键技术研究[C]//铝冶炼节能新技术研讨会论文集.焦作:河南省科学技术协会, 2011:5-30. [4] WU Y M, XIONG J, LAI R M, et al. The microstructure evolution of an Al-Mg-Si-Mn-Cu-Ce alloy during homogenization[J]. Journal of Alloys and Compounds, 2009, 475(1/2):332-338.
[5] HAGA T, NISHIYAMA T, SUZUKI S. Strip casting of A5182 alloy using a melt drag twin-roll caster[J]. Journal of Materials Processing Technology, 2003, 133(1/2):103-107.
[6] HAGA T, SUZUKI S. Study on high-speed twin-roll caster for aluminum alloys[J]. Journal of Materials Processing Technology, 2003, 143/144: 895-900.
[7] 陈自伟, 吴立鸿, 卢广玺,等. AA8011铝合金高通量连铸连轧铸嘴堵塞的原因[J]. 轻合金加工技术, 2017, 45(7):32-36. [8] 卢广玺, 王鹏, 关绍康. 哈兹列特连铸连轧AA5052铝合金铸嘴挂渣成分及形成机理研究[J]. 郑州大学学报(工学版), 2014, 35(5):112-115. [9] 康志成, 毛大垣, 邓圭玲. 铝熔体粘度测量的研究[J]. 湖南有色金属, 2001, 17(2): 18-20. [10] 韩占忠, 王敬, 兰小平. FLUENT:流体工程仿真计算实例与应用[M]. 北京:北京理工大学出版社, 2004:9-10. [11] 刘慎, 王西科, 关绍康. 铝连续铸轧铸嘴型腔的数值模拟及其结构优化[J]. 有色金属加工, 2013, 42(4):44-46. [12] 郭彦宏, 王金辉, 李戬. 铝合金双辊铸轧铸嘴内部熔体流动数值模拟及对表面质量的影响[J]. 赤峰学院学报(自然科学版), 2012(16):60-61. [13] 谭宏斌. 连续莫来石纤维应用与制备[J]. 玻璃钢/复合材料, 2009(3):71-75. [14] 叶大伦, 胡建华.实用无机物热力学数据手册(第二版)[M]. 北京:冶金工业出版社,2002:987-992. [15] 黄希祜. 钢铁冶金原理[M]. 北京: 冶金工业出版社, 2013. [16] DENG T F, FANG J Y, LAN S. The relation of pyroplastic deformation and liquid viscosity in vitreous ceramics[J]. Journal of the Australian Ceramic Society, 2017, 53(2): 635-643.
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