| 摘要 |
<p>This invention is directed to a method of making a substantially pure killed or semi-killed steel ingot by means of a bottom pouring method or a top pouring method. The process comprises making the temperature of the molten steel before casting more than the solidification temperature plus 20.degree.C and coating the top surface of melt in the ingot mould, during the pouring operation of the molten steel or immediately thereafter, with a high calorie heat retaining agent of the quickly combustible type in sufficient quantity that the total calorific value per ton of the molten steel becomes more than 1800 Kcal. The heat retaining agent is of the type in which the peak time from the start of the exothermic reaction to reaching the maximum temperature is within four minutes thereby decreasing and controlling the accumulation of impurities in the mushy zone of the steel ingot bottom.</p> |
