Analysis Of Steel Teeming Effect In New Slide Gate System With Electromagnetic Induction

Nowadays, with the higher demands in practice, the quality of steel is becoming an important factor in steel market in order to maximize profits. Steel quality requirements mainly reflect in improving the cleanliness of the steel. However, most of clean steel with the higher cleanliness in China is mainly dependent on foreign imports, which is a major bottleneck for China’s steel industry. To meet national policies and the development requirements of efficiency, energy saving, and environmental protection, our group has proposed a new electromagnetic steel teeming method. Compared with the traditional steel tapping method, its main feature is that:iron-carbon alloy particles with the similar or the same compositions as molten steel is used as drainage agent to replace the traditional ladle filler sand. In open pouring stage, the solidified shell in the upper nozzle is quickly melted by use electromagnetic induction heating device at the bottom of the ladle to achieve open tapping. This approach not only improves the auto-casting rate which can reach to100%, and reduce the labor intensity of workers, but also improves the cleanliness of liquid steel, creates good conditions for the development of high value-added steel.In the electromagnetic system, whether the system equipment is fast and efficient open casting will become a vital reference point. In order to achieve the purpose of fast steel tapping, we self-designed experimental device to study the influences of the different material, particle size, shape of iron-carbon alloy, and upper nozzle’s materials, load power on the steel tapping under the same liquid steel temperature. On the other hand, in this system, taking into account how to install the induction coil at the bottom of the ladle to achieve the excellent steel tapping effects and device security, solid-liquid interface location should be determined carefully. We also investigated the changes of the solid-liquid interface under different conditions, such as the physical parameters of the iron-carbon alloys. Through experimental data analysis, the results provided important theoretical support for the electromagnetic steel industrial application and valuable reference data for future experiments.The main results are shown as follows:(1) Under the same conditions, compared with the cast steel particles, by use of cast iron particles as the fillers, the solid-liquid interface downshifting is higher and the open casting time is less; The influence of the shape of the iron-carbon alloy particles on the solid-liquid interface downshifting is not very obvious; the larger the iron-carbon alloy particle size, the greater the downshifting of the solid-liquid interface; when Φ2.0mm of spherical cast iron particles used as fillers, the open casting effect is best;(2)Under the conditions of the temperature of the molten steel is1600℃and the Φ2.0mm spherical cast iron particles are used as fillers, the distance h from the coil top to the bottom of the crucible and the open casting time t shows a variation of the exponential function;(3) The effect of graphitic upper nozzle on the pouring effect is better than high aluminum nozzle. However, the graphitic upper nozzle with poor anti-erosion and anti-oxidation capacity should not be used as the nozzle. Under the requirements of satisfying the open casting effect, it is necessary to use aluminum nozzle as far as possible.