Optimization of Vortex Slag Entrainment during Ladle Teeming Process in the Continuous Casting of Automobile Outer Panel

With the thinner of the automobile panel, the press crack defects caused by the large-size calcium aluminate inclusions at the automakers become obvious. Herein, in order to stabilize the control of calcium aluminate inclusions in the molten steel, the vortex slag entrainment (VSE) of a 300 ton ladle is investigated by the numerical simulation. The effects of the steel throughput, cofferdam height close to the nozzle, and ladle bottom structure on the VSE are analyzed. Results demonstrate that the residual molten steel (RMS) in the ladle and the critical height of the vortex increase with the increasing of the steel throughput. The RMS increases with the increasing of the cofferdam height when the VSE occurs. When the cofferdam height is 50, 100, and 150 mm, the RMS are 4.71, 7.19, and 9.62 t at the initial time of the VSE with a 7.5 ton min⁻¹ steel throughput. In addition, the industrial trial of transforming the flat bottom ladle into the slope bottom ladle is carried out to control the VSE and reduce the RMS. The average weight of the RMS after pouring 25 heats of the slope ladle bottom ladle is 1.85 t less than that of the flat bottom ladle.