LF炉无铝脱氧的工艺实践

PROCESS PRACTICE OF Al-FREE DEOXIDATION IN LF

介绍了承钢120t系统对钢中酸溶铝没有要求钢种的LF炉无铝脱氧实践。精炼过程中采用硅钙钡、硅钙粉、电石、碳化硅等对钢水进行无铝脱氧工艺,减少了钢水中的Als和Al2O3,精炼过程中加入Al2O3含量较低的精炼渣系,提高炉渣碱度,降低SiO2的活度,大幅提高硅的脱氧能力;优化钙处理工艺,对钢水进行深脱氧,通过夹杂物变性控制夹杂物的形态和尺寸。实践证明,对钢中酸溶铝没有要求的钢种采用无铝脱氧工艺后,没有降低钢水质量,提高了钢水可浇性,吨钢精炼费用降低2.96元/t。

The paper introduces the process practice of Al-free deoxidation in 120t LF system for steel grades that has no requirement on acid-soluble aluminum in steel. During refining process, by adding sil- icon calcium barium, silicon calcium powder, carbide and SIC to steel for Al-free deoxidation refining, Als and Al2O3 in steel are reduced. During refining process, by adding refining slag with lower content Al2O3, slag alkalinity is increased, SiO2 activeness is reduced, and silicon deoxidation ability is sharply improved. By optimizing calcium process, deep deoxidation on liquid steel can be carried out, and through inclusion property change, inclusions form and size are controlled. Practice has proved that after Al-free deoxidation process for steel grades that has no requirement on acid-soluble aluminum in steel, molten steel quality is not reduced, the castability is improved, and refining cost is reduced by 2.96 Yuan/t.