转炉冶炼汽车用钢脱磷工艺  

Deep dephosphorization of IF steel in converter

作　　者：赵东伟[1] 李海波[1] 孙亮[2] 张勇[2] 闫小柏 

机构地区：[1]首钢技术研究院薄板所,北京100043 [2]首钢股份公司迁安钢铁公司炼钢部,河北迁安064404 [3]北京首钢自动化信息技术有限公司自动化研究所,北京100041

出　　处：《钢铁研究学报》2017年第12期997-1005,共9页Journal of Iron and Steel Research

摘　　要：为了减少RH吹氧升温对洁净度的影响,汽车用钢在转炉冶炼过程中终点温度往往更高,从而导致转炉冶炼过程脱磷困难。通过对渣钢间脱磷热力学和动力学的计算,分析了转炉"留渣+双渣"工艺条件下磷分配比与钢液成分、炉渣成分以及温度的关系;结合工业生产试验,通过改变倒渣时间以及调整炉渣成分并对转炉冶炼过程钢液、炉渣连续取样,研究了转炉"留渣+双渣"工艺条件下的脱磷变化规律并得出了快速脱磷的工艺条件:吹炼开始加入小块废钢和轻薄料快速增加炉渣FeO含量并控制钢液温度的升高,吹氧量达到40%时倒出高磷含量炉渣;吹氧量为40%~80%期间增加炉渣FeO含量,减少炉渣返干,防止钢液回磷;转炉终渣碱度控制在4.0左右,终渣TFe质量分数在18%~20%和尽量低的出钢温度。RH oxygen top-blowing for raising temperature should be avoided to improve the cleaniness of IF steel as far as possible,which made the end point temperature of converter higher and then dephosphorization in converter became difficult.Thermodynamics and dynamics of dephosphorization process in converter were calculated to study the relationship of phosphate partition ratio to compositions of molten steel,slag,temperature in molten steel based on slag-remaining and double slag process.Through changing the first deslagging time and the composition of slag,then serial sampling from molten steel and slag in industrial production experiments,the behavior of phosphorus in molten steel was studied and then the main measures obtaining higher phosphate partition ratio in slag-remaining and double slag process are：small-sized scrap or thin steel sheet should be used to increase FeO content in slag and prevent molten steel temperature increase when oxygen blowing in converter begins.Slag with high phosphorus content should be poured when amount of oxygen blowing reachs 40% of the total;FeO content in slag should be increased to assure the mobility of slag and then reduce rephosphorization from slag to steel when amount of oxygen blowing is greater than 40% and less than 80% of the toal;the end-point slag with 4.0 basicity and 18 mass%-20 mass% FeO content and molten steel temperature should be controlled.

关 键 词：转炉 高温出钢 脱磷 热力学 动力学 汽车用钢 

分 类 号：TF713[冶金工程—钢铁冶金]