The buildup behavior of Al203 in the continuous caster tundish nozzle during the time when
reoxidation of molten steel is in progress in the tundish was studied. The study revealed that molten FeO formed in the tundish during reoxidation of molten steel,with some part of the molten FeO still remaining unreduced, flows through the tundish nozzle into the mold. It also revealed that Al203 particles,ranging from a few to approximately 10 μm in size, built up in the tundish nozzle while forming FeAl204 between these particles. From the results of this study and an analysis made by using a newly proposed model for Al203 buildup,it is considered that Al203 particles in the molten steel adhere to the nozzle face, with molten FeO serving as a binder, and are not removed by the stream of molten steel running through the nozzle.