METHOD FOR PREVENTING AIR OXIDATION OF MOLTEN STEEL AT INITIAL STAGE OF POURING IN TUNDISH

摘要

PURPOSE:To surely prevent air oxidation of molten steel at initial stage of pouring under low cost by using iron plate having the specific height and thickness as a tundish bottom weir just below a long nozzle. CONSTITUTION:As the weir 6 in the tundish 3 just below the long nozzle 2, the iron, of which the height is higher than the lowest position of the long nozzle 2 and the material is melted by the molten steel heat, is used. In this case, the thick rotate for the weir 6 is selected so as to melt down during the time from the timing (a) when the molten steel level comes to submerge the lower end of the long nozzle 2 to the timing (b) when its level comes to almost fell at the weir height. That is, air oxidation and nitrogen absorption of the molten steel can de prevented. Further, at the time of continuing the pouring of the molten steel from the long nozzle 2, as the iron plate weir 6 comes to melt-down at early time, the ascending flow of the molten steel and enclosing of the float-up slag by the iron plate weir 6 are eliminated, and the stable operation is executed as ordinal operation.