Influence of Ladle Exchange on Inclusions in Transition Slabs of Continuous Casting for Automotive Exposed Panel Steel

Abstract

In the present work, inclusion analyses were carried out for inclusions in the tundish samples and in the 28 m transition slabs produced during the ladle exchange of heats A and B. At the beginning of heat B steel casting, the 12th meter of the casting slabs was in the position of the mold meniscus. The number of densities of the inclusions containing TiN and the inclusions containing Al2O3+TiN increased significantly from the 12th meter to the 22nd meter, while the number densities of the inclusions containing Al2O3 markedly increased from the 13th meter to the 20th meter. Therefore, the length of the transition slabs whose cleanliness was seriously reduced was about 10 m starting from the beginning of heat B steel casting. It was deduced that the contamination of the transition slabs could be caused by the liquid steel exposure in the tundish, the inflow of ladle filling sand of the next heat, or the entrainment of the tundish flux due to the fluctuation of the tundish liquid level at the beginning of heat B steel casting.