1. Lianyuan Iron and Steel Corporation of Hunan Hualing, Loudi 417000, Hunan, China; 2. School of Metallurgical and Material Engineering, Hunan University of Technology, Zhuzhou 412007, Hunan, China
Abstract:In order to study the influence factors of inclusions in steel,two different deoxidization methods were adopted to investigate the influence of alloy addition sequence on inclusions in LG700 steels during complex deoxidization. In methodⅠ, Al was added first followed by Si-Mn alloy. In method Ⅱ, Si-Mn alloy was added first followed by Al. Afterward, the contents of oxygen and nitrogen and the microscopic inclusions in the steel were analyzed and the formation process of deoxidized products was deduced. The results showed that the alloy addition sequence had no obvious effect on the total oxygen content of the molten steel, but the content of nitrogen content in the steel deoxidized by method Ⅱ was significantly lower than that by method Ⅰ. It had an influence on the size and composition of the initial inclusions, resulting in the difference of growth and removal capacity, which caused the difference of the size, composition and particle size distribution of inclusions in steel. According to the experimental results, when method Ⅱwas used for deoxidization, the composite Al2O3-MnO-SiO2 inclusions were more favorable to be removed, thus reducing the number of large inclusions in steel.