| 摘要 |
PROBLEM TO BE SOLVED: To stably produce steel small in inclusions originated from deoxidized products and excellent in cleanliness by adding Al and Ba to molten steel and controlling the form of inclusions to be formed so as to form the compsn. of Al2O3-BaO system compsn. contg. a specific concn. of BaO. SOLUTION: Molten steel is incorporated with Al and Ba in this order to form an Al2O3-BaO system compsn. contg. 5 to 50 wt.% BaO. In accordance with the use of the kinds of steel to be treated, treatment of dehydrogenation, decarburization or the like is executed, moreover, if required, the components of C, Si, Mn or the like are controlled, next, Al is added to the molten steel 3 in a vacuum tank 5 from a raw material charging port 11, and deoxidation is executed. As the Al to be added, metallic Al, an Al alloy or the like is used, and the amt. of Al to be added is controlled to a degree by which Al of >=0.01 wt.% remains in the molten steel 3 after the deoxidation. After the addition of Al, Ba is added to the molten steel 3 from the raw material charging port 11. As the Ba to be added, metallic Ba, a Ba alloy or the like are used.
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