Numerical analysis of the comprehensive effect of continuous casting process parameters on the continuous casting billet remelting

In the present study, a coupled 3-D model of flow, solidification, and heat transfer was established to apply to gain new insights into the effects of casting speed and nozzle diameter on the remelting of continuous casting billets. The effects of nozzle diameters and casting speeds on the remelting of continuous casting billet were analyzed separately. Nozzle diameters vary from 20 mm to 50 mm, and casting speed varies from 1 m/min to 4 m/min. The flow behavior and velocity distribution, which are at different casting speeds, were calculated, and the reasons for shell remelting at high casting speeds were analyzed. The remelting of the billet shell, which is at different combinations of different nozzle diameters and casting speeds, was calculated. Then, the comprehensive effects of nozzle diameters and casting speeds on the remelting of the billet shell are analyzed. Finally, the remelting degree maps of different continuous casting process parameters were presented. By the simulation, it is found that the casting speed has more obvious effects on whether the remelting phenomenon occurs, while the diameter of the nozzle has more obvious effects on the degree of remelting. When the casting speed is lower than 2 m/min, remelting does not appear. When the casting speed is higher than 3 m/min, remelting will occur. When the casting speed is 3 m/min, as the nozzle diameter increases, the remelting degree continues to decrease, and the range of remelting first remains stable, then gradually decreases. It can be observed that when the casting speed is increased to 3-4 m/min, the nozzle diameter should be in the range of 30-40 mm.