YANG Jun
,
WANG Xin-hua
,
JIANG Min
,
WANG Wan-jun
钢铁研究学报(英文版)
The influence of calcium treatment on non-metallic inclusions had been studied when control technology of refining top slag in ladle furnace was used in ultra-low oxygen steelmaking. A sufficient amount aluminium was added to experimental heats for final deoxidizing during BOF tapping, and the refining top slag with strong reducibility, high basicity and high Al2O3 in ladle furnace was used to produce ultra-low oxygen steel and the transformation of non-metallic inclusions in molten steel was compared by calcium treatment and no calcium treatment. The results show that the transformation of Al2O3→MgO·Al2O3 spinel→CaO-MgO-Al2O3 complex inclusions has been completed for aluminum deoxidation products and calcium treatment to molten steel is unnecessary when using the control technology of ladle furnace refining top slag to produce ultra-low oxygen steel, and the complex inclusions are liquid at the temperature of steelmaking and easily removable to obtain very high cleanliness steel by flotation. Furthermore, the problems of nozzle clogging in casting operations do not happen and the remaining oxide inclusions in steel are the relatively lower melting point complex inclusions.
关键词:
ultra-low oxygen
,
top slag
,
deoxidization
,
aluminium
,
oxide inclusion
,
calcium treatment
杨俊，王新华
钢铁
对超低氧试验钢精炼过程中镁铝尖晶石的形成机制和生成热力学计算分析表明：1873K时，MgO-Al2O3二元系夹杂物中MgO的质量分数超过17%时就能生成镁铝尖晶石；采用高碱度、w((CaO))/w((Al2O3))≈1、强还原性精炼顶渣对铝终脱氧钢液进行LF精炼时，在LF精炼中前期就实现Al2O3向MgO·Al2O3尖晶石的转变；钢液中的镁则是实现Al2O3向MgO·Al2O3尖晶石转变的中介和桥梁。而钢中镁含量是由酸溶铝控制的。因此，保持钢液中足够的铝含量是镁铝尖晶石生成的前提。生产过程中，当钢液的w(［Al］)达到0.03%时，w(［Mg］)只需要1.32×10-7以上就能生成MgO·Al2O3尖晶石。
关键词:
超低氧
,
aluminium deoxidation
,
magnesia-alumina spinel
,
Al-Mg-O
