Interface behavior of steel–slag–air during tundish filling process: physical modeling and mathematical simulation
摘要
In view of the frequent deterioration of molten steel quality during the tundish filling process, the slag–steel–air interface behavior in a tundish, including liquid level fluctuation, slag eyes, slag entrapment and air suction during the steady-state casting and filling process, was comparatively studied through physical modeling and mathematical simulation methods. During the filling process, the liquid surface forms a large-size slag eye under the impact of molten steel from a ladle shroud, which simultaneously results in a violent fluctuation of liquid level. Concurrently, the liquid flow entrains the air phase and the cover slag into the tundish impact zone, resulting in slag entrapment and air suction. At filling flow rates of 1.5Q, 2.0Q, and 2.5Q (Q is the flow rate under steady-state casting), the amount of slag entrapped is 8.39 × 10–5, 9.65 × 10–5, and 12.7 × 10–5 m3, respectively, while the volume of air aspirated is 0.84 × 10–4, 1.47 × 10–4, and 2.01 × 10–4 m3, indicating that slag entrapment and air suction intensify with an increase in tundish filling flow rate. Flow field characterization identifies eddy currents in the impact zone as the primary driver of the above phenomena. Proper filling process parameters were proposed to improve the steel quality during the tundish filling.