| 摘要 |
<p>PURPOSE:To prevent slopping and to increase the heat input to molten steel in the decarburization of molten steel under reduced pressure by adding a slag making agent and/or slag on the surface of molten steel in a vacuum vessel to make oxidative slag. CONSTITUTION:The lower parts of the circulating pipe 10a (riser) and circulating pipe 10b (downcommer) fixed to the lower part of the vacuum vessel 3 of an RH-type circulative degasifier are dipped in the molten steel 1a in a ladle 2, and the exhaust pipe 6 and vessel 3 are evacuated by a vacuum pump. A part of the molten steel 1a in the ladle is sucked up into the vessel as shown by 1b (molten steel in vessel). A gaseous oxygen jet 12 is blown against the surface of the molten steel 1b from the upper part of the vessel 3 through an oxygen lance 8, and a slag making agent and/or slag are added on the surface of the molten slag 1b from a hopper 4a through a feed chute 4b to form a cover slag 9. The decarburizing rate is increased in this way.</p> |
