低锰钢冶炼工艺开发与应用

Development and Applications of Smelting Process for Low Manganese Steel

工业纯铁要求钢中锰含量控制在0.005%以内,为了研究低锰钢冶炼工艺,对脱锰反应的热力学和动力学条件进行了分析。研究表明,钢水温度越低、炉渣氧化性越高、钢水氧含量越高、炉渣中氧化锰含量越低则锰的氧化反应越容易进行。当铁水锰含量在0.040%~0.055%时,将转炉吹炼后钢水终点碳含量控制在0.025%~0.035%,终点温度控制在1620℃以下,可将钢水残锰含量降低到0.04%~0.08%。钢水脱锰率随着转炉渣量的增加而升高。转炉出钢过程中不对钢水进行脱氧处理,钢包中的钢水和炉渣保持较高氧化性,在LF精炼处理过程中,可以使钢中锰含量平均降低32%,降幅为0.01~0.04个百分点。采用转炉和LF炉联合脱锰工艺,可稳定地将钢中锰含量降低到0.05%以内。

The armco iron requires the manganese content in steel to be controlled within 0.005%.In order to study the smelting process for low manganese steel,the thermodynamic and dynamic conditions of demanganization reaction are analyzed.The study showed that the lower the temperature of liquid steel was,the higher the oxidizability of slag and oxygen content in steel were as well as the lower the manganese oxide content in slag was,the easier the oxidation reaction of manganese was.When the manganese content in liquid iron is 0.040%~0.055%,the end point carbon content of liquid steel in converter after bessemerizing is controlled at 0.025%~0.035%and final temperature is controlled below 1620℃so that residual manganese content in liquid steel could be reduced to 0.04%~0.08%.The demanganization rate of liquid steel increases with the quantity of converter slag increases.Without the deoxidation during tapping of converter,the liquid steel and slag in ladle would maintain higher oxidizability.During the refining process in ladle furnace(LF),the manganese content in steel could be reduced by 32%on average and decreasing amplitude is 0.01~0.04 percentage points.The manganese content in steel could be reduced steadily within 0.05%with the combined demanganization processes of converter and LF.