PURPOSE: To improve quality and yield of an ingot by arranging a submerged nozzle at molten steel pouring hole in a ladle, sealing the molten steel surface with oxidizing prevention agent and further pouring the molten steel at the specific raising speed of the molten steel.
CONSTITUTION: The upper end of the submerged nozzle 4a is closely brought into contact with the molten steel pouring hole 3 in the ladle 1 and the lower end 4b thereof is arranged in the mold 5. At the initial time of pouring the molten steel, the lower end 4b of the nozzle is positioned near surface of a bottom plate 6 and at the same time of starting the pouring, the molten steel surface is sealed with the oxidizing prevention agent 8. Next, the ladle 1 is raised and the raising speed of the molten steel is set to 5W50 cm/min. By this method, scattering of the molten steel at the time of pouring is surely prevented, and as the contact with the air is eliminated, the oxidation of the molten steel is prevented. Therefore, the quality and yield of the ingot are improved.
OURA SHINOBU
FUJII MASAMI
SAEKI TADASHI
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