| 摘要 |
PURPOSE:To prevent the local over-heating of molten steel at the upper part of a ladle, to decrease the melting loss of the ladle refractory, and to reduce the heat segregation at the upper part of the ladle and to strengthen the reducing refining, by controlling automatically as relating an input electric power control mechanism into the electrodes, to a gas supplying rate control mechanism into the ladle. CONSTITUTION:At the time of the refining, the inert gas is supplied a little too much from a porous plug 4 at first under condition as ascending the electrodes 6 to stir the molten steel 2, and slag making materials are charged from a charging hole 7. Next, the electrodes 6 are descended and a gas supplying rate is decreased by turning down a flow rate control value 13 through the gas supplying rate control device 16 and the arc heating is executed by supplying much electric power to the electrodes 6 from the input electric power control device 25. Then, during stopping arc by ascending the electrodes 6, the flow rate control valve 13 is opened by the gas supplying rate control device 16 to increase the gas supplying rate. Such a control is automatically executed by a command from a microcomputer 17.
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