Patents by Inventor Syunichi Ootsuka

Syunichi Ootsuka 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).

  • High-carbon chromium bearing steel and production method of the same
    Patent number: 8808470
    Abstract: Provided is a production method including: heating a workpiece at a temperature higher than an Ac1 transformation point in a carburizing atmosphere; slowly cooling the workpiece at not more than 70° C./Hr down to a temperature T satisfying Formula (1) while maintaining the carburizing atmosphere: Ar1?20?T(° C.)?300° C. . . . (1); and cooling the workpiece in an oxidizing atmosphere. According to this method, it is possible to efficiently produce a high-carbon chromium bearing steel whose depth of the recarburized layer or the overcarburized layer is within a range from 0 to 0.2 mm, having less machining allowance, and excellent in machinability, using a steel tube after hot tube-making.
    Type: Grant
    Filed: December 13, 2011
    Date of Patent: August 19, 2014
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Syunichi Ootsuka, Yoshitaka Nishiyama, Tadashi Kawakami
  • HIGH-CARBON CHROMIUM BEARING STEEL AND PRODUCTION METHOD OF THE SAME
    Publication number: 20130263972
    Abstract: Provided is a production method including: heating a workpiece at a temperature higher than an Ac1 transformation point in a carburizing atmosphere; slowly cooling the workpiece at not more than 70° C./Hr down to a temperature T satisfying Formula (1) while maintaining the carburizing atmosphere: Ar1?20?T(° C.)?300° C. . . . (1); and cooling the workpiece in an oxidizing atmosphere. According to this method, it is possible to efficiently produce a high-carbon chromium bearing steel whose depth of the recarburized layer or the overcarburized layer is within a range from 0 to 0.2 mm, having less machining allowance, and excellent in machinability, using a steel tube after hot tube-making.
    Type: Application
    Filed: December 13, 2011
    Publication date: October 10, 2013
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Syunichi Ootsuka, Yoshitaka Nishiyama, Tadashi Kawakami