Abstract
The No. 1 Steelmaking Shop of Kawasaki Steel Corp. Mizushima Works has two circular arc type bloom casters with mold size ranging from 200 × 220 mm to 400 × 560 mm.
In this paper, the influence of casting conditions on internal defects of large cross section bloom casts has been studied, especially the molten steel flow in the pool caused by immersed nozzle and elctromagnetic stirrer.
The multi-pore immersed nozzle has been proved to be superior to the single-pore nozzle, in increasing aercal percentage of equiaxed crystals of casts and in decreasing accumulation of inclusions. The amount of large inclusions in large cross section bloom is less than in the case of smaller ones. A mathematical model to predict the amount of large inclusions accumulated in the upper side of bloom casts is presented. The influence of electromagnetic stirring on the center segregation and negative segragation at the part of white band is made clear, and low segregation casts can be obtained by choosing a proper electromagnetic stirring condition.
