| 摘要 |
<p>PROBLEM TO BE SOLVED: To produce a low carbon steel, etc., excellent in the cleanliness by specifying the ratio of CaO, etc., to Al quantity in a deoxidizer, at the time of executing deoxidizing treatment by adding the deoxidizer composed of metallic Al and CaO, etc., to non-deoxidized molten steel. SOLUTION: The non-deoxidized molten steel melted in a converter, etc., is tapped into a ladle, and slag reforming agent is added at need to execute the reforming of the slag. The deoxidizer composed of metallic Al or Al- containing alloy and CaO or Cao-containing flux is added into this molten steel in the ladle by using a bubbling device, electromagnetic stirring device, etc., to execute the deoxidizing treatment. At this time, in the case of using Y wt% for the pure CaO content in the deoxidizer and X wt% for the pure Al content, the ratio of Y/X is regulated to be 1-2. By this method, the low carbon steel or the extra-low carbon steel remarkably improved in the cleanliness is obtd.</p> |
