| 摘要 |
PURPOSE: A method of refining a molten metal for an electrical sheet is provided to obtain high quality of molten metal refining for manufacturing target steel and to continuously cast steel sheets without problems such as clogging of nozzles owing to temperature fall of molten metal. CONSTITUTION: A temperature and an oxygen density of a molten metal are measured in a ladle(5). That is, A vapor pressure of a vacuum bath(1) is about 7.0kg/cm¬2 to secure initial vacuum if the molten metal has the oxygen density of 200-250PPM and low temperature of 1590°C owing to temperature fall of molten metal in flowing into the ladle. At the same time, Ar gas of 200Nm3 per hour is supplied to a rising pipe(3) deposited into the ladle to return the molten metal, and the elements of molten metal is adjusted by injecting Fe-P alloy iron through an inlet(8). After about 3min, oxygen is sprayed at a high speed through a nozzle(7) and about 1-3kg of Al per ton of molten metal is injected through the inlet to raise the temperature of molten metal if the oxygen in molten metal is secured not less than 400ppm.
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