| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for desulfurizing molten steel using an RH vacuum-degassing apparatus. <P>SOLUTION: When performing desulfurization of the molten steel by projecting a desulfurization flux from a projection lance attached to an RH vacuum-degassing apparatus to the molten steel in a vacuum vessel of the RH vacuum-degassing apparatus, cooling water of a condenser of a vacuum exhaust device attached to the RH vacuum-degassing apparatus is analyzed, preferably pH value is measured, and this value is fed back, and a projecting amount of the desulfurization flux is adjusted. The projecting amount of the desulfurization flux to be furthermore added is calculated from the relationship between the preliminarily computed analysis value of the cooling water of the condenser and the amount of the desulfurization flux dissolved in the cooling water of the condenser on the basis of the obtained analysis value of the cooling water of the condenser, and it is preferable to adjust the projecting amount of the desulfurization flux. Herewith, hitting ratio of the S amount in the molten steel is improved, S amount variation of the molten steel is reduced, and yield ratio of the molten steel is improved. <P>COPYRIGHT: (C)2012,JPO&INPIT |
