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:
Dec. 14, 2004
Filed:
Dec. 30, 2003
Ryuji Nakao, Hikari, JP;
Tomoaki Tanaka, Hikari, JP;
Masao Igarashi, Hikari, JP;
Koichiro Yoshino, Hikari, JP;
Nippon Steel Corporation, Tokyo, JP;
Abstract
The present invention: solves the problems of hitherto disclosed technologies, such as insufficient suppression of the oxidation loss of [Cr] and the excessive erosion of refractories, in the decarburization-refining of chromium-contained molten steel under a normal or reduced pressure; and is characterized by: determining, in sequence; a molten steel temperature during the refining through actual measurement or computation from a molten steel temperature before the refining and refining conditions; [C] and [Cr] concentrations during the refining through actual measurement or computation from molten steel components before the refining and refining conditions; a CO partial pressure P in an atmosphere during the refining from the total pressure P of the atmosphere, an oxygen gas supply rate and an inert gas supply rate, a Hilty's equilibrium temperature T from said [C] and [Cr] concentrations and P ; the difference &Dgr;T between said molten steel temperature during the refining and said Hilty's equilibrium temperature T : and controlling the refining conditions so that said &Dgr;T is equal to a prescribed value or higher.