Patents by Inventor Okitomo Kunitake

Okitomo Kunitake has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Method for refining molten steel and apparatus therefor
    Patent number: 6432164
    Abstract: A method for refining molten steel by immersing the lower opening end of a cylindrical immersion tube equipped with a lance into the molten steel contained in a ladle, controlling the pressure in the cylindrical immersion tube to a prescribed pressure range to suck up the molten steel, injecting an agitation gas from the bottom of the ladle towards the surface of the sucked-up molten steel, and decarburizing and refining the molten steel under a reduced pressure, characterized in that the method comprising the steps of; controlling the pressure Pt (Torr) in the cylindrical immersion tube so as to satisfy the following formulae (1) and (2), blowing oxygen gas to the surface of the molten steel through the lance, and decarburizing and refining the molten steel under a reduced pressure; Pt>760−1.297×107/Dc2  (1) K=1.71×Dl0.211×Dc0.438×Wm−1.124×Qg0.519×Pt−0.410>0.
    Type: Grant
    Filed: February 15, 2001
    Date of Patent: August 13, 2002
    Assignee: Nippon Steel Corporation
    Inventors: Okitomo Kunitake, Norio Omura, Wataru Sakai, Susumu Mukawa, Tadashi Imai