为减少钢中硅酸盐夹杂,改善钢的质量,1964年公司曾将部分下注沸腾钢改为上注。但上注后,浇注时间较下注延长了半倍至一倍。同时,在200吨盛钢桶中使用55%左右的高铝塞头砖出现严重冲刷,尤其在浇注后期,钢流几乎控制不住,致使漏钢率显著增加,以4月份为例,下注漏钢率为2.4%,而上注高达 In order to reduce the inclusion of silicates in the steel and improve the quality of the steel, in 1964 the company changed part of the betting and boiling steel to bet. But after betting, the pouring time was extended by a factor of one to two. At the same time, the use of high-alumina plug bricks in about 200 tons of steel drums has caused serious erosion. Especially at the late stage of pouring, the steel flow is almost uncontrollable, resulting in a significant increase in the leakage rate. In April, for example, bets were placed. Breakout rate is 2.4%, and the payout is as high as