| 摘要 |
PROBLEM TO BE SOLVED: To provide a process for refining molten steel in an RH degasser which can reduce the amount of inclusions in the molten steel derived from slags sucked into a vacuum tank compared to conventional processes. SOLUTION: In the process for refining molten steel in the RH degasser, a tubular tank equipped with two dip tubes at its bottom is dipped in the molten steel retained in a ladle. The pressure inside the tubular tank is reduced to reflux the molten steel between the ladle and the tubular tank while successively subjecting the molten steel to various refining processes. Here, the dip tubes are dipped into the molten steel, wherein the submergence depths of the dip tubes are less deeper than those employed in normal refining for a given period of time after initiating the refining by reducing the pressure inside the tubular tank. Thereafter, refining is performed by dipping the dip tubes as deep as in the normal refining. COPYRIGHT: (C)2003,JPO
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