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. 18, 2025
Filed:
May. 12, 2022
Jfe Steel Corporation, Tokyo, JP;
Hidemitsu Negishi, Tokyo, JP;
Rei Yamada, Tokyo, JP;
JFE STEEL CORPORATION, Tokyo, JP;
Abstract
A molten steel denitrification method, wherein an extremely low nitrogen concentration range is stably reached in a short time without use of a top-blown gas, is a denitrification process wherein CaO—and—AlO-containing slag formed by a combination of an Al addition step of adding a metal—Al-containing substance to molten steel to deoxidize and turn the molten steel into Al-containing molten steel and a CaO addition step of adding a CaO-containing substance to the molten steel is brought into contact with the Al-containing molten steel to remove nitrogen in the molten steel, in which the molten steel is stirred at a stirring power density ε of 60 W/t or higher. In the denitrification process, a surface of the molten steel or the slag is subjected to an atmosphere of 1.0×10Pa or lower. In a steel production method, the obtained molten steel is cast after the components are adjusted.