Effect of CaF2 Contents in Slag on Inclusion Absorption in a Bearing Steel

In the current study, laboratory experiments of the slag‐steel reaction are performed to investigate the effect of CaF 2 contents in the refining slag on the inclusion absorption of the bearing steel. The increase of the CaO/Al 2 O 3 ratio effectively enhances the absorption of inclusions by slag. The increase of the CaO/Al 2 O 3 ratio enhances the driving force of the inclusion dissolution and lowers the slag viscosity. It is noted that the excessive CaO/Al 2 O 3 ratio led to the formation of solid phases in the slag, lowering the absorption effect of slag. The appropriate addition of CaF 2 in the slag is helpful to remove inclusions while aggravating the corrosion of MgO crucibles. The addition of CaF 2 mainly reduces the viscosity and melting temperature of slag. The inclusion removal factor is proposed to effectively evaluate the inclusion removal rate in steel during slag steel reaction. As a result, the most recommended composition of slags is 7% CaF 2 ; the CaO/Al 2 O 3 ratio is 2.0.