| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for efficiently manufacturing a high-nitrogen-containing steel with little oxide inclusions. SOLUTION: The method for manufacturing the high-nitrogen-containing steel comprises: in a step of refining a molten steel by vacuum degassing it along with stirring, blowing a mixed gas of Ar and N<SB>2</SB>or a N<SB>2</SB>gas into the molten steel for 20 minutes or longer so as to satisfy expressions (1) and (2), wherein Q<SB>Ar</SB>indicates an Ar gas-blowing rate (NL/min molten steel ton); Q<SB>N2</SB>indicates a N<SB>2</SB>gas-blowing rate (NL/min molten steel ton); C<SB>N, aim</SB>indicates a targeted nitrogen concentration (ppm) in the steel when the refinement is finished; and P indicates a degree of vacuum (Pa) in vacuum degassing: and thereby stirring the molten steel. COPYRIGHT: (C)2004,JPO
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