顶底复吹转炉冶炼45~#硬线钢终点硫的控制

The End Sulfur Control of 45~# Hard Wire Steel Smelting in Top and Bottom Combined Blown Converter

对马钢70 t顶底复吹转炉冶炼45#硬线钢硫的物料平衡及转炉脱硫的影响因素进行分析,在此基础上,依据原辅料条件,控制入炉硫含量且对转炉冶炼脱硫操作参数进行优化,实现终点硫的有效控制。应用结果表明,控制入炉总硫量≤10 kg,转炉炉渣碱度在3.5～4.0,渣中(FeO)质量分数在10%～20%,转炉终点温度在1 630～1 650℃,转炉终点回硫得到改善,终点平均回硫质量分数由之前的0.007%下降至0.004%,终点硫合格率由之前的70%提高到96%以上。

The material balance of sulfur and the influencing factors of desulphurization of smelting 45# hard wire steel in 70 t top and bottom combined blowing converter were analyzed. Based on that, according to the conditions of the raw materials, content of sulfur in furnace was controlled, and the operation parameters of desulphurization in converter were optimized to achieve the effective control of end sulfur. The application results show that the total content of sulfur in the furnace is less than 10 kg, the basicity of converter slag is 3.5-4.0, mass fraction of FeO in the slag is 10%-20%, and the end point temperature of converter is at 1 630-1 650℃, the resulphurization in the end of the converter is reduced, and at the end point the average sulfur content of resulphurization decreases from 0.007% to 0.004%, the qualification rate of end sulfur increases from 70% to over 96%.