转炉底吹氮氩切换对氮质量分数影响

为了研究转炉底吹气体对钢水终点氮质量分数影响，研究了迁钢210 t顶底复吹转炉底吹模式对转炉终点氮质量分数的影响，并基于钢液脱氮和吸氮理论对试验结果进行了分析。应用实践结果表明，随着铁水碳质量分数增加以及终点氧质量分数降低，终点氮质量分数逐渐降低；在铁水条件、副原料、转炉终点、底吹流量以及过程操作一致条件下，随着氮氩切换时间节点延长，钢液增氮量逐渐增加。当切换时间节点为吹氧比56%以内，底吹氮氩切换对终点钢水氮质量分数影响较小，当切换时间节点为吹氧比高于56%时，终点钢水氮质量分数增幅较大。

Influence of nitrogen and argon switching on nitrogen mass fraction in converter bottom blowing

In order to study the effect of bottom blowing gas on the end point nitrogen mass fraction of molten steel, the effect of bottom blowing mode on the end point nitrogen mass fraction of 210 t top bottom combined blowing converter at Qiansteel was studied, and the experimental results were analyzed based on the theory of denitrification and nitrogen absorption of molten steel. The application results showed that with the increase of C mass fraction in hot metal and the decrease of the end point O mass fraction, the N mass fraction in the end point decreases gradually. Under the same conditions of the molten iron, by material, end point of the converter, bottom blowing flow rate and process operation, the nitrogen increment in molten steel increased gradually with the extension of the node of nitrogen argon switching time. When the switching time was less than 56% of oxygen blowing ratio, the effect of bottom blowing nitrogen and argon switching on the nitrogen mass fraction of molten steel was small. When the switching time was more than 56%, the nitrogen mass fraction of molten steel increased greatly.