Patents by Inventor Hisamichi Nagahara

Hisamichi Nagahara 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).

  • Chromized heat-resistant alloy members and a process for the production thereof
    Patent number: 5958152
    Abstract: To provide heat-resistant alloy members that maintain the resistance to corrosion at high temperature of the chromized layer formed on Ni- or Co-base heat-resistant alloys and which yet are improved in various mechanical properties. The improved Ni- or Co-base heat-resistant alloy member having a chromized layer that is characterized by having a chromium concentration of 25-80% and a thickness of 10-100 .mu.m. This member is produced by controlling both the vapor pressure of a chromium halide being used in chromization and the temperature therefor in such a way that the chromized layer being formed is adjusted to have a chromium concentration and a thickness within the ranges specified above.
    Type: Grant
    Filed: May 23, 1997
    Date of Patent: September 28, 1999
    Assignees: Ebara Corporation, Tocalo Co., Ltd.
    Inventors: Shuhei Nakahama, Hisamichi Nagahara, Masamichi Kawasaki, Yoshio Harada
  • Chromized heat-resistant alloy members and a process for the production thereof
    Patent number: 5882439
    Abstract: To provide heat-resistant alloy members that maintain the resistance to corrosion at high temperature of the chromized layer formed on Ni- or Co-base heat-resistant alloys and which yet are improved in various mechanical properties. The improved Ni- or Co-base heat-resistant alloy member having a chromized layer that is characterized by having a chromium concentration of 25-80% and a thickness of 10-100 .mu.m. This member is produced by controlling both the vapor pressure of a chromium halide being used in chromization and the temperature therefor in such a way that the chromized layer being formed is adjusted to have a chromium concentration and a thickness within the ranges specified above.
    Type: Grant
    Filed: September 11, 1996
    Date of Patent: March 16, 1999
    Assignees: Ebara Corporation, Tocalo Co., Ltd.
    Inventors: Syuhei Nakahama, Hisamichi Nagahara, Masamichi Kawasaki, Yoshio Harada
  • Method of forming carbide-base composite coatings, the composite coatings formed by that method, and members having thermally sprayed chromium carbide coatings
    Patent number: 5789077
    Abstract: Thermally sprayed coatings made from carbides of metals having greater carbon affinity than Cr in the presence of free carbon, or thermally sprayed coatings made from carbides of metals having smaller carbon affinity than Cr are heat treated in a chromium halide containing atmosphere which also contains hydrogen gas, whereby activated metallic Cr is precipitated in a fine particulate form, which is allowed to act on the thermally sprayed coatings, whereupon a Cr.sub.23 C.sub.6 -form carbide is created not only on the coating surface but also in its interior, particularly within pores, to form a modified layer, thereby compositing the thermally sprayed coatings.
    Type: Grant
    Filed: June 26, 1995
    Date of Patent: August 4, 1998
    Assignees: Ebara Corporation, Tocalo Co., Ltd.
    Inventors: Syuhei Nakahama, Hisamichi Nagahara, Masamichi Kawasaki, Yoshio Harada, Junichi Takeuchi