废钢比对转炉钢液过氧化的影响及配料调优

The Effect of Scrap Ratio on the Peroxidation of Molten Steel in Converter and the Optimization of Ingredient

转炉终点钢液过氧化不仅会造成合金收得率降低,冶炼成本增加,还会导致脱氧产物增多,钢液洁净度变差。因此,避免转炉终点钢液过氧化一直是工艺控制的重点。针对国内某特钢厂100 t转炉终点钢液过氧化严重的问题,本文通过数据统计发现,该厂平均废钢比高达26%,平均终点C含量仅有0.055%,平均终点温度为1 605℃。在未考虑炉内热平衡的前提下,采取高废钢配料导致了炉内热量不足,从而被迫采取补吹升温,引发终点碳、温度命中率低以及钢液过氧化现象。因此,本文基于该厂的原料条件,从优化炉料结构的维度出发,建立了最大废钢比计算模型,综合考虑原料条件来配加废钢,减少了需要补吹升温的炉次。模型应用后,转炉终点温度平均提高10℃,终点碳含量平均提高0.036%,钢液自由氧含量平均下降206.3×10^(-6),降本提质效果显著。

The Peroxidation of molten steel at the end of the converter will not only lead to the decrease of alloy yield and the increase of smelting cost,but also lead to the increase of deoxidation products and the poor cleanliness of molten steel.Therefore,it is always the key point of process control to avoid the peroxide of molten steel at the end of converter.Aiming at the problem of terminal peroxide of 100 t converter in a domestic factory,this study finds that the average scrap ratio of this factory is up to 26%,the average terminal C content is only 0.055%,and the average terminal temperature is 1605℃.Without considering the heat balance in the furnace,the adoption of high scrap steel batching resulted in insufficient heat in the furnace,which forced the supplementary blowing to raise the temperature,resulting in a low hit rate of the terminal carbon and temperature,and then lead to the problem of molten steel peroxidation.Therefore,from the perspective of optimizing the burden design,this study establishes the calculation model of the maximum scrap ratio based on the raw material conditions of the plant.In the actual production,the raw material conditions are comprehensively considered to add scrap,which reduces the number of heats requiring supplementary blowing for temperature rise.After the application of the model,the end point temperature of converter increases by 10℃,the end point carbon content increases by 0.036%,and the oxygen content of molten steel decreases by 206.3×10^(-6).The data shows that the effect of cost reduction and quality improvement is significant.