| 摘要 |
PURPOSE:To produce a titled low hydrogen steel stably in a short treatment time by blowing a CaO-contg. flux to molten steel which is beforehand subjected to a disoxidizing treatment thereby disoxidizing and desulfurizing the steel then subjecting the same to a vacuum degassing treatment followed by blowing of a Ca alloy to the molten steel. CONSTITUTION:A CaO-contg. flux is blown by a carrier gas to the molten steel which is beforehand subjected to a disoxidizing treatment, whereby said steel is dis oxidized and desulfurized. The content of hydrogen in the molten steel is increased by this desufurization stage. Therefore, the steel is next subjected to a vacuum degassing treatment to decrease the content of hydrogen in the molten steel down to about a desired level. A Ca alloy is blown to this steel to control the form of sulfide in the molten steel. At this time, the content of hydrogen changes hardly and is maintained at a low level. Therefore, in this way, it is possible to produce the low hydrogen steel stably. |
