| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for stably manufacturing a high cleanliness steel containing an extremely small amount of inclusions, by promoting the separation and removal of the non-metallic inclusions from the steel while inhibiting them from forming. SOLUTION: The method for manufacturing the high cleanliness steel through removing the inclusions from the molten steel by previously dissolving a soluble gas in the molten steel to be treated when vacuum degassing the molten steel, subsequently depressurizing the molten steel, and floating the inclusions along with thereby generated gas bubbles comprises the steps of: dissolving the soluble gas at first during converter smelting or after having finished the smelting; adding a slag-modifying agent into the flow of the molten steel tapped out from a converter; and then blowing the soluble gas singly or together with an inert gas, into the molten steel in a ladle prior to the vacuum degassing treatment. COPYRIGHT: (C)2006,JPO&NCIPI
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