Patents by Inventor Chizui Toyokihara

Chizui Toyokihara 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).

  • Process for producing high strength stainless steel of duplex structure having excellent spring limit value
    Patent number: 5178693
    Abstract: A process for the production of a stainless steel strip having excellent spring characteristics as such and good formability, wherein a cold rolled strip of a stainless steel comprising, in addition to Fe, from 10.0 to 20.0% by weight of Cr, from 0.01 to 0.15% by weight of C, and at least one of Ni, Mn and Cu in an amount of from 0.1 to 4.0% by weight, is continuously passed through a continuous heat treatment furnace where it is heated to a temperature range for a two-phase of ferrite and austenite, rapidly cooled to provide a strip of a duplex structure, consisting essentially of ferrite and martensite, optionally temper rolled at a rolling reduction of not more than 10%, and continuously passed through a continuous heat treatment furnace to effect aging of not longer than 10 minutes.
    Type: Grant
    Filed: March 15, 1991
    Date of Patent: January 12, 1993
    Assignee: Nisshin Steel Co., Ltd.
    Inventors: Katsuhisa Miyakusu, Teruo Tanaka, Hiroshi Fujimoto, Chizui Toyokihara