The effect of substituting CaO with BaO and CaO/Al₂O₃ ratio on the viscosity of CaO–BaO–Al₂O₃–CaF₂–Li₂O mold flux system was studied by rotational viscosity method. The results showed that the viscosity increased with increasing BaO as a substitute for CaO, while the viscosity decreased with the increase in CaO/Al₂O₃ ratio. The viscous activation energy of the slags is from 92.1 kJ·mol⁻¹ to 133.4 kJ·mol⁻¹. Either the Arhenius or the Weymann–Frenkel equation can be applied to establish the viscosity prediction model. In this paper, the Weymann–Frenkel equation and a new optical basicity with regard to Al₂O₃ as an acidic oxide were applied to the modified NPL model for predicting the viscosity of CaO–BaO–Al₂O₃–CaF₂–Li₂O mold flux system. The estimated viscosity is in good agreement with the measured viscosity.

In the current study, the three-dimensional fluid flow, heat transfer and solidification in FC-Mold continuous casting strands were simulated, and the influences of upper and lower magnetic fields of FC-Mold on the distribution of inclusions beneath the surface of the slab were discussed, considering the washing effect of flow on the solidifying front. The results indicate that the influence of FC-Mold on fluid flow in steel continuous casting mold is determined by the choice of SEN and the intensity of upper and lower magnetic fields. Larger upper magnetic field intensity was not recommended due to high flow speed at meniscus. The maximum flow speed at meniscus was 0.48 m/s when the upper magnetic intensity was 0.68 T in the current simulation. After applying FC-Mold, more superheated molten steel was brought to the upper recirculation zone contributing to temperature increase at meniscus. With regard to the entrapment of inclusions, a criterion was established and validated, considering the effect of flow on the motion of inclusions. Increasing the intensity of upper and lower magnetic fields could make the region 5 mm below the surface become cleaner, and eliminate the aggregation of inclusions.