Numerical Simulation of Molten Steel Flow under a Magnetic Field with Argon Gas Bubbling in a Continuous Casting Mold
Numerical Simulation of Molten Steel Flow under a Magnetic Field with Argon Gas Bubbling in a Continuous Casting Mold
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DOI：
10.2355/isijinternational.44.556
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发表时间：
2004-03
影响因子：
1.8
通讯作者：
N. Kubo;T. Ishii;J. Kubota;T. Ikagawa
中科院分区：
文献类型：
--
作者：
N. Kubo;T. Ishii;J. Kubota;T. Ikagawa
在连铸过程中，必须防止保护渣和氩气泡夹带造成的表面缺陷。通过实验可知，降低自由液面下钢液流速是防止保护渣卷渣的最有效方法之一。为此，我们已经通过电磁水平稳定器（EMLS）系统使用了电磁力，该系统施加从模具窄面移动到喷嘴出口下方的模具中心的低频交变磁场。在这项研究中，钢液在结晶器中的流动进行了数值分析，以优化条件，防止恶化的现象：优化的电磁力与氩气鼓泡。模拟结果表明，氩气气泡在水口附近因浮力而上升，上升的氩气气泡诱导钢液逆流。由于电磁力，迫使钢水在施加磁场的区域中朝向磁场行进方向流动。因此，钢液以较小的外加磁场流向自由表面附近的结晶器中心，并且以较大的外加磁场流向窄面。可以选择一个合适的外加磁场和氩气鼓泡，以最大限度地减少流速和保护渣夹带量。
In a continuous casting process, it is essential to prevent the surface defects which are caused by the entrapments of both mold powder and argon gas bubbles. It is well known through experiments that the decrease in the molten steel flow velocity just under the free surface is one of the most effective methods for the prevention of mold powder entrapments. For this purpose, we have already employed the electromagnetic force by the ElectroMagnetic Level Stabilizer (EMLS) system, which applies a low frequency alternating magnetic field that moves from the narrow face of the mold to the mold center below the nozzle exits. In this study, the molten steel flow in a mold was numerically analyzed to optimize the conditions for the prevention of the deteriorating phenomena: optimization of electromagnetic force with argon gas bubbling. Simulation results indicate that argon gas bubbles ascend near the nozzle due to their buoyancy, and ascending argon bubbles induce the upstream of the molten steel. Due to the electromagnetic force, the molten steel is forced to flow toward the magnetic field traveling direction in the region where the magnetic field is imposed. Consequently, the molten steel flows toward the mold center near the free surface with a smaller imposed magnetic field, and it flows toward the narrow face with a larger imposed magnetic filed. A suitable imposed magnetic filed with argon gas bubbling can be chosen to minimize the flow velocity and also the amount of mold powder entrapments.