Modeling reoxidation behavior of Al-Ti-containing steels by CaO-Al2O3-MgO-SiO2 slag

作者:Ren, Ying; Zhang, Li-Feng*; Zhang, Ying
来源:Journal of Iron and Steel Research International, 2018, 25(2): 146-156.
DOI:10.1007/s42243-018-0015-5

摘要

A kinetic model was developed using FactSage Macro Processing to simulate the reoxidation of Al-Ti-containing steels by CaO-Al2O3-SiO2-MgO slags. The calculated results show a good agreement with the experimental data. Thus, the developed kinetic model can be used to predict changes in slag, steel, and inclusion compositions during the reaction process. During the slag reoxidation process, the reactions occurring at slag-steel interface and in the bulk steel were confirmed to be the reduction of SiO2 by [Al] and [Ti] and the self-dissociation of SiO2 into [Si] and [O]. Increasing the ratio of CaO to SiO2 in the slag can significantly suppress the self-dissociation of SiO2 in the slag and lower the amount of inclusions produced during reoxidation. The formed inclusions changed from solid Al2O3 to Al2O3-TiO (x) inclusions, which was mainly dependent on the w([Al]) and w([Ti]). The amount of inclusions was obviously influenced by the composition of the top slag.