摘要 Only a few Chinese enterprises can produce high-quality industrial pure iron, and studies on the smelting process of industrial pure iron were limited. The inclusions in a melting process were characterized by means of electron microscopy and an automatic inclusion analysis system, and the evolution mechanism of inclusion was studied using thermodynamic calculation to optimize the calcium alloy addition in liquid window. The results show that during the smelting process, inclusions mainly composed of Al2O3 and spinel are formed before calcium treatment. After calcium treatment, they continuously react with [Ca], [S] and [Ti], grow up, and are removed during refining and tundish pouring. In the end, there are more small-sized inclusions containing CaS, and the contents of Al2O3 and spinel are less. According to thermodynamic calculations, the appropriate calcium treatment liquid window for the molten steel composition is (10–38) 9 10–6. Calcium treatment has changed the main types of inclusions in industrial pure iron from Al2O3 to small-sized inclusions containing CaS and effectively reduces the influence of Al2O3 inclusions on the quality of industrial pure iron.
Abstract：Only a few Chinese enterprises can produce high-quality industrial pure iron, and studies on the smelting process of industrial pure iron were limited. The inclusions in a melting process were characterized by means of electron microscopy and an automatic inclusion analysis system, and the evolution mechanism of inclusion was studied using thermodynamic calculation to optimize the calcium alloy addition in liquid window. The results show that during the smelting process, inclusions mainly composed of Al2O3 and spinel are formed before calcium treatment. After calcium treatment, they continuously react with [Ca], [S] and [Ti], grow up, and are removed during refining and tundish pouring. In the end, there are more small-sized inclusions containing CaS, and the contents of Al2O3 and spinel are less. According to thermodynamic calculations, the appropriate calcium treatment liquid window for the molten steel composition is (10–38) 9 10–6. Calcium treatment has changed the main types of inclusions in industrial pure iron from Al2O3 to small-sized inclusions containing CaS and effectively reduces the influence of Al2O3 inclusions on the quality of industrial pure iron.
Xin Liu,Yan-ping Bao,Cheng-jian Hua, et al. Denaturation behavior of inclusions in industrial pure iron by calcium treatment[J]. Journal of Iron and Steel Research International, 2023, 30(02): 249-258.
2023, Vol. 30 
