Numerical Simulation of Influence of Casting Speed Variation on Surface Fluctuation of Molten Steel in Mold

The influences of casting speed variation on surface fluctuation of the molten steel of mold during continuous casting were investigated with numerical simulation method. It was found that, when the casting speed was evenly decreased from 1.4m/min to 0.6m/min, increases of the surface fluctuation of the molten steel of mold were observed only on time that was at the start of casting speed change. While, in experiment of increasing casting speed evenly from 0.6m/min to 1.4m/min, increases of the surface fluctuation of the molten steel of mold were observed only at the time when the casting speed was stopped to increase after it had been increased to 1.4m/min. For surface fluctuation of the molten steel of mold which was produced during the casting speed evenly increasing or decreasing period and at the time when increasing or decreasing the casting speed at low casting speed level (0.6m/min), the influence of casting speed change was very small. In addition, it was found that, at high casting speed level (1.4m/min), even a little change of casting speed could result in remarkable increase of the surface fluctuation. Thus, at high casting speed, changing casting speed should be avoided or using much slower speed changing rate.