Reaction Between High Mn-High Al Steel and CaO-SiO2-Type Molten Mold Flux: Retardation of Al2O3 Accumulation at High Al Content ([pct Al](0) >= 5) in Steel and Low MgO Content ((pct MgO)(0) <= 1.8) in Flux

A series of steel-flux reaction experiments was conducted to elucidate the reaction mechanism between high Mn-high Al steel and CaO-SiO2-type molten mold flux of low MgO content ((pct MgO)(0) = 0 to 1.8) at 1723 K (1450 degrees C). Composition evolutions in the liquid steel and the molten flux during the reaction and microstructure change in the flux near the steel-flux interface were investigated by employing different experimental techniques. 4Al + 3(SiO2) = 3Si + 2(Al2O3) was confirmed as a major reaction in the system. It was found that rate of Al2O3 accumulation in the flux was retarded as the initial Al content in the steel ([pct Al](0)) increased from 1 to 5 or 11, approximately. Moreover, keeping the initial content of MgO in the flux ((pct MgO)(0)) = 5) and low MgO content ((pct MgO)(0) <= 1.8). The formation of a calcium aluminate layer in the low-MgO flux was beneficial to retarding the reaction rate. (C) The Minerals, Metals & Materials Society and ASM International 202011Nsciescopu