METHOD FOR OPENING POURING HOLE IN LADLE AND FILLING MATERIAL USED THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide a method for opening a pouring hole in a ladle with which the sintering of iron powder as a filling material is prevented and the pouring hole in the ladle is easily opened. SOLUTION: In the method for opening the pouring hole in the ladle performed, with which the filling material is beforehand packed into a molten metal pouring nozzle arranged at the bottom part of the ladle and provided with a sliding valve adjustable to molten metal flowing quantity before receiving the molten steel into the ladle, and when the pouring hole in the ladle is opened, the sliding valve is operated and the molten metal pouring nozzle is opened by blowing oxygen with an oxygen pipe to melt the filling material; this method is regulated as the followings, that is, the above filling material is used for iron powder, and an oxygen concentration (X%) in the iron powder is made to 0.5-3.0% and in the whole iron powder, the ratio (Y%) of≥250μm grain diameter is made to be in the range satisfying the following formulas (1) and (2). In the range of 0.5≤X≤2.0, Y≥-20×X+90...(1). In the range of 2.0