LF炉精炼过程气体氮含量的控制  

NITROGEN CONTENT CONTROL IN LF FURNACE REFINING PROCESS

作　　者：司军亮 智新龙 杜亚杰 Si Junliang;Zhi Xinlong;Du Yajie(First Steelmaking Division of Jingye Iron and Steel Co.,Ltd.,Shijiazhuang 050400,Hebei)

机构地区：[1]敬业钢铁有限公司第一炼钢事业部,河北石家庄050400

出　　处：《河北冶金》2024年第9期51-54,共4页Hebei Metallurgy

摘　　要：针对敬业钢铁公司板坯生产中LF精炼环节增氮量高达11.2 ppm,最终成品氮含量超45 ppm的问题,从钢液增氮原理进行了分析,发现钢液的增氮速度与钢液和空气的接触面积、空气中氮的浓度、钢液温度等因素有关。围绕导致增氮速度加快的因素,在LF精炼炉进行了一系列生产试验,试图降低精炼过程中钢液增氮量。通过液态渣回收,减少钢液与空气的接触面积,可将LF精炼过程的增氮量由4.2 ppm控制到1.1 ppm;通过减少送电时间和送电频次,降低在高温状态下的钢水增氮,可将精炼过程增氮量由3.1 ppm控制到2.1 ppm;通过合理控制强搅拌时间,减少钢水裸露时间,可降低过程增氮量;通过保持炉内微正压,降低氮气浓度,也可降低过程增氮量。采取上述措施后,大梁钢在LF精炼过程中平均增氮量从11.2 ppm下降到了5.5 ppm内,取得了良好的控氮效果。Aiming at the problem that the nitrogen increases in LF refining process of Jingye Iron and Steel Co.,Ltd.and reaches 11.2 ppm,resulting in the nitrogen content of final product exceeding 45 ppm.The principle of nitrogen increase in liquid steel is analyzed,and it is found that the nitrogen increase rate of liquid steel is related to the contact area between liquid steel and air,the concentration of nitrogen in air,the temperature of liquid steel and other factors.A series of production tests are carried out in LF refining furnace to try to reduce the nitrogen increase in liquid steel during the refining process.By recovering liquid slag and reducing the contact area between liquid steel and air,nitrogen increase in LF refining process can be controlled from 4.2 ppm to 1.1 ppm.The nitrogen increase in the refining process can be controlled from 3.1 ppm to 2.1 ppm by reducing the power supply time and frequency to reduce the nitrogen increase in the molten steel at high temperature.The nitrogen increase in the process can be reduced by controlling the strong mixing time reasonably and reducing the exposure time of molten steel.By maintaining the micro-positive pressure in the furnace,the nitrogen concentration can be reduced even the nitrogen increase in the process can be reduced.After taking the above measures,the average nitrogen increase of large beam steel in the refining process decreased from 11.2 ppm to 5.5 ppm,and a good nitrogen control effect is achieved.

关 键 词：LF精炼 氮含量 液态渣回收 送电时间 强搅拌时间 增氮 

分 类 号：TF769.2[冶金工程—钢铁冶金]