| 摘要 |
PURPOSE:To add efficiently desired elements into molten steel and to remove inclusions in a short time by admitting the molten steel in a ladle under pressure into a degassing device to flow the same cyclically and adding elements of high vapor pressure into the molten steel. CONSTITUTION:A ladle 2 in which molten steel is received is moved upward to immerse the reflux pipe 4 of an RH type degassing device into molten steel 3. The inside of a degassing vessel 1 is substd. with an inert gas, and the space 9 in the upper part of the ladle 2 is pressurized with the inert gas to admit the molten steel into the vessel 1. An inert gas is blown through the pipe 4 into the vessel 1 to apply reflux power on the molten steel therein. Additive elements of high vapor pressure such as Ca, Cs, Ng or the like are added from the upper part of the vessel 1 under continuation of the above-mentioned treatment. The pressure in the vessel 1 is maintained under atmospheric pressure or pressure during the addition. The additive alloys are included into the reflux flow of the molten steel and are efficiently incorporated therein. |
