Patents by Inventor Isao Matoba

Isao Matoba 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).

  • Grain-oriented silicon steel sheet having a low iron loss free from deterioration due to stress-relief annealing and a method of producing the same
    Patent number: 5173129
    Abstract: A grain-oriented silicon steel sheet having a low iron loss free from deterioration due to the stress-relief annealing, can be obtained by forming on its surface a forsterite film locally having regions, which have a thickness different from that of the remaining regions in the film, or locally having filmless regions which do not coat the steel sheet surface.
    Type: Grant
    Filed: December 8, 1989
    Date of Patent: December 22, 1992
    Assignee: Kawasaki Steel Corporation
    Inventors: Ujihiro Nishiike, Michiro Komatsubara, Yoshiaki Iida, Isao Matoba
  • Grain-oriented silicon steel sheet having a low iron loss free from deterioration due to stress-relief annealing and a method of producing the same
    Patent number: 4952253
    Abstract: A grain-oriented silicon steel sheet having a low iron loss, due to the subdividing effect of magnetic domain wall spacing, free from deterioration due to the stress-relief annealing, can be obtained by forming on its surface a forsterite film locally having regions, which have a thickness different from that of the remaining regions in the film, or locally having filmless regions which do not coat the steel sheet surface.
    Type: Grant
    Filed: November 5, 1987
    Date of Patent: August 28, 1990
    Assignee: Kawasaki Steel Corporation
    Inventors: Ujihiro Nishiike, Michiro Komatsubara, Yoshiaki Iida, Isao Matoba
  • Grain-oriented silicon steel sheet having a low iron loss free from deterioration due to stress-relief annealing and a method of producing the same
    Patent number: 4655854
    Abstract: A grain-oriented silicon steel sheet having a low iron loss free from deterioration due to the stress-relief annealing, can be obtained by forming on its surface a forsterite film locally having regions, which have a thickness different from that of the remaining regions in the film, or locally having filmless regions which do not coat the steel sheet surface.
    Type: Grant
    Filed: October 22, 1984
    Date of Patent: April 7, 1987
    Assignee: Kawasaki Steel Corporation
    Inventors: Ujihiro Nishiike, Michiro Komatsubara, Yoshiaki Iida, Isao Matoba
  • Method of producing grain-oriented silicon steel sheets having excellent magnetic properties
    Patent number: 4517032
    Abstract: A grain-oriented silicon steel sheet having high magnetic induction and low iron loss can be produced by controlling properly the particle size of carbide precipitated in the crystal grains of the steel sheet before final cold rolling. Further, the magnetic properties can be more improved by adjusting the C content in a starting silicon steel depending upon the Si content in the steel and removing a proper amount of C from the steel during the course after completion of hot rolling and before final cold rolling, in addition to the proper control of the particle size of carbide precipitated in the crystal grains of the steel sheet before final cold rolling.
    Type: Grant
    Filed: March 11, 1983
    Date of Patent: May 14, 1985
    Assignee: Kawasaki Steel Corporation
    Inventors: Tomomichi Goto, Katsuo Iwamoto, Yoshinori Kobayashi, Isao Matoba
  • Method of producing grain-oriented silicon steel sheets having excellent magnetic properties
    Patent number: 4439252
    Abstract: A grain-oriented silicon steel sheet having excellent magnetic properties can be stably produced by adjusting properly the C content in a silicon steel to be used as a starting material depending upon the Si content in the steel, removing a proper amount of C from the steel during the course after the hot rolling and before the final cold rolling, and further carrying out the final cold rolling at a reduction rate of 40-80%.
    Type: Grant
    Filed: September 23, 1982
    Date of Patent: March 27, 1984
    Assignee: Kawasaki Steel Corporation
    Inventors: Katsuo Iwamoto, Tomomichi Goto, Yoshinori Kobayashi, Yoshiaki Iida, Isao Matoba
  • Method for producing grain-oriented electrical steel sheets or strips having a very high magnetic induction
    Patent number: 4212689
    Abstract: A grain-oriented electrical steel sheet having a very high magnetic induction is obtained by developing secondary recrystallized grains at a specifically limited secondary recrystallization temperature in a cold rolled silicon steel sheet containing substantially no antimony and aluminum and having a specifically limited low nitrogen content.
    Type: Grant
    Filed: May 2, 1977
    Date of Patent: July 15, 1980
    Assignee: Kawasaki Steel Corporation
    Inventors: Yoh Shimizu, Yoshiaki Iida, Tomomichi Goto, Hiromi Mitsunori, Isao Matoba
  • Method for producing single-oriented electrical steel sheets having a high magnetic induction
    Patent number: 3940299
    Abstract: Single-oriented electrical steel sheets having a high magnetic induction are produced by combining specifically limited conditions in the composition of raw material, the final cold rolling reduction rate and in the secondary recrystallizing annealing.
    Type: Grant
    Filed: September 26, 1974
    Date of Patent: February 24, 1976
    Assignee: Kawasaki Steel Corporation
    Inventors: Isamu Goto, Isao Matoba, Takuichi Imanaka, Ko Matsumura, Yoh Shimizu, Tomomichi Goto, Takahiro Kan