The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 08, 2011
Filed:
Feb. 06, 2007
Applicants:
Chikashi Tada, Tokyo, JP;
Chitoshi Matsumura, Kawasaki, JP;
Inventors:
Chikashi Tada, Tokyo, JP;
Chitoshi Matsumura, Kawasaki, JP;
Assignee:
JFE Steel Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C21C 1/04 (2006.01); C21C 5/34 (2006.01); C21C 7/076 (2006.01);
U.S. Cl.
CPC ...
Abstract
Molten steel is refined in an electric furnace by using iron scrap as a main iron source, and is tapped into a separate refining vessel. Thereafter, metallic-Al containing material and CaO are added onto a bath surface of the molten steel, and an oxygen containing gas is supplied to the molten steel. Thereby, a nitrogen-removal reaction utilizing an AlN formation reaction is caused to proceed. Consequently, even in the case of molten steel having a low carbon content, a low-nitrogen steel can be refined and produced at low costs.