保护渣的黏度是评价连铸过程润滑效果的重要指标,合适的黏度是保证连铸过程均匀润滑和传热的关键。基于多相流和热焓-多孔介质模型,建立了二维非稳态模型研究结晶器振动过程弯月面处液渣的流动行为,对比了不同黏度的保护渣的润滑过程的差异。黏度测试结果表明,超低碳钢保护渣添加质量分数9%的Al2O3后,保护渣高温(1 300 oC)黏度明显升高,黏度-温度曲线特征表明保护渣逐渐由结晶渣变成玻璃渣。计算结果表明,黏度增大后,弯月面处液渣的流动速度减小,液渣膜厚度减薄,渣消耗量减少,且在不同的振动周期内液渣膜厚度和渣消耗量变化无明显的周期性变化。
Abstract
Viscosity of mold flux is an important property to evaluate the lubrication during the continuous casting of steel, and viscosity with proper value is the key to ensure uniform lubrication and heat transfer during continuous casting of steel.Based on the multiphase flow and enthalpy-porous media model, a two-dimensional transient model was established to study the infiltration of liquid flux into the mold-strand gap at the meniscus, and the effect of viscosity on the lubrication was discussed. The measurement shows that with 9% Al2O3 addition into mold flux designed especially for the continuous casting of ultra-low carbon steel, the viscosity of mold flux at 1 300 ℃ was increased, and the trend of the viscosity as a function of temperature indicated that the mold flux gradually transformed from crystal to glass type. The prediction shows that as the viscosity increased, the flow speed of liquid flux at meniscus was attenuated, the liquid film thickness and flux consumption were decreased. Moreover, the fluctuation of inflow and the thickness of liquid film varied with no obvious periodic change during the oscillation cycle.
关键词
保护渣 /
连铸 /
黏度 /
润滑 /
数值模拟 /
消耗量
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Key words
mold flux /
continuous casting /
viscosity /
lubrication /
numerical simulation /
consumption
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参考文献
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脚注
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基金
国家自然科学基金资助项目(51804057)
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