Distribution of Defects in Slab and Suppression of Unbalanced Flow by Electromagnetic Brake in Continuous Casting Mold

摘要

The flow of molten steel in the continuous casting mold affects surface defects such as blow-holes and slivers caused by gas bubbles and non-metallic inclusions. In recent years, higher surface quality has been required in steel sheets for automotive outer panels. High throughput conditions in continuous casting induce penetration of inclusions into the deep region1) and entrainment of mold flux caused by increased mold level fluctuation,2) and thereby degrade the quality of slabs. However, by applying an electromagnetic brake in the mold, it is possible to suppress the penetration of inclusions into the deep region and mold level fluctuation.3) It is also known that unbalanced flow is induced by nozzle clogging or sliding nozzle gate movement, and unbalanced flow increases under high throughput conditions.4-5).