PRODUCTION OF DEFECTLESS INGOT

摘要

PURPOSE:To improve the quality of an ingot by decreasing the discharge angle at the top end of an immersion nozzle for continuous casting in a region where the discharge rate of a molten steel is low and increasing said angle in the region where said rate is high in mold pouring using said immersion nozzle thereby adjusting the fluctuation of the molten steel surface and allowing the inclusion in the molten steel to float satisfactorily. CONSTITUTION:The discharge angle at the top end of the immersion nozzle in the mold is set at 10-20 deg. downward if the discharge rate is about <=3T/min and said angle is set at 30-40 deg. downward if the discharge rate is about >=3T/min. The fluctuation of the molten metal surface in the mold is thereby adjusted and the inclusion carried into said metal is floated as far as possible. The internal quality of the ingot is improved by such satisfactory floating and sepn. of the inclusion.