Patents by Inventor Hajime Esaka

Hajime Esaka 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 hardness and high toughness nitriding powder metallurgical high-speed steel
    Patent number: 4671930
    Abstract: A high-speed steel obtained by powder metallurgy processing wherein a chemical composition includes, by weight %,C: a quantity (%) which satisfies with the following formula ##EQU1## where Ceq=0.19+0.017 (W+2Mo)+0.22 VN, W, Mo and V are respectively the content (%) in steel______________________________________ Cr: 3-5% V: 6.0-8.5% Mo: 4-7.5% Co: 5-15% W: 5-7% N: 0.2-1.7% ______________________________________and the remainder is Fe, and (W+2Mo) is 15-20% is disclosed.
    Type: Grant
    Filed: June 18, 1985
    Date of Patent: June 9, 1987
    Assignee: Kabushiki Kaisha Kobe Seiko Sho
    Inventors: Nobuyasu Kawai, Minoru Hirano, Hajime Esaka, Hirofumi Fujimoto
  • High hardness and high toughness nitriding powder metallurgical high-speed steel
    Patent number: 4599109
    Abstract: A high-speed steel obtained by powder metallurgy processing having a chemical composition which includes, in weight %,C: a quantity (%) which satisfies the formulaCeq+0.15.ltoreq.C+12/14 N.ltoreq.Ceq+0.35where Ceq=0.19+0.017 (W+2Mo)+0.22V, andN, W, Mo and V are respectively the content (%) in steel______________________________________ Cr: 3-5% V: 4.0-6.0% Mo: 8-12% Co: 5-15% W: 8-14% N: 0.2-1.2% ______________________________________and the remainder is Fe, and (W+2Mo) is 27-32%, is disclosed.
    Type: Grant
    Filed: June 18, 1985
    Date of Patent: July 8, 1986
    Assignee: Kabushiki Kaisha Kobe Seiko Sho
    Inventors: Nobuyasu Kawai, Minoru Hirano, Hiromune Manto, Hajime Esaka, Hirofumi Fujimoto