Formation of CaO·TiO_2-MgO·Al_2O_3 dual phase inclusion in Ti stabilized stainless steel

摘要

The formation of CaO·TiO_2-MgO·Al_2O_3 dual phase inclusion in 321 stainless steel was investigated in the laboratory. The result indicated that the condition for the formation of CaO·TiO_2-MgO·Al_2O_3 in 321 steel is [Ca] > 0.001 wt%, [Ti] > 0.1 wt%, and [Al] > 0.01 wt%. The mechanism is the following: Al_2O_3 inclusion turns into CaO-Al_2O_3 after Ca-Si wire is fed into the molten steel; [Mg] is then obtained by reducing MgO in slag or crucible wall by [Al] and [Ti]; finally CaO-Al_2O_3 inclusion is changed into CaO·TiO_2-MgO·Al_2O_3 by the reaction with [Mg], [Ti], and [O] in the molten steel simultaneously.