Variation of meniscus shape and initial steel solidification under different steel–slag interfacial tension in continuous casting mold of slab

A two-dimensional model was applied to investigate the influence of the interfacial tension between the steel and the slag on the behavior of the meniscus in continuous casting mold of slab. The shape of the meniscus and phenomena near the meniscus were revealed, and the profile of the slag rim and the depth of the solidified meniscus and oscillation marks with different interfacial tension of the steel and slag were compared. With the increase in the interfacial tension, the size of the curved meniscus increased, while the curvature and the height of the local meniscus close to the mold decreased. Besides, the thickness of the slag rim, solid slag and total slag near the meniscus had the tendency to increase, and the bottom of the slag rim became lower and thicker. With the increase in the interfacial tension from 0.1 to 2.5 N/m, the location of the largest heat flux near the meniscus decreased from 10.0 to 2.5 mm above the initial level of the steel, and the largest heat flux was within 3.52–4.58 MW/m². Meanwhile, the largest depth of the solidified meniscus decreased from 3.3 to 2.3 mm, and the depth of oscillation marks decreased, which was conducive to the shallow hook at the subsurface of the slab, and the improvement of surface cleanliness of the slab.