Patents by Inventor Yasumasa Hirai

Yasumasa Hirai 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).

  • Patent number: 9034120
    Abstract: Provided is bearing steel excellent in workability after spheroidizing-annealing and in hydrogen fatigue resistance property after quenching and tempering. The bearing steel has a chemical composition containing, by mass %: 0.85% to 1.10% C; 0.30% to 0.80% Si; 0.90% to 2.00% Mn; 0.025% or less P; 0.02% or less S; 0.05% or less Al; 1.8% to 2.5% Cr; 0.15% to 0.4% Mo; 0.0080% or less N; and 0.0020% or less O, which further contains more than 0.0015% to 0.0050% or less Sb, with the balance being Fe and incidental impurities, to thereby effectively suppress the generation of WEA even in environment where hydrogen penetrates into the steel, so as to improve the roiling contact fatigue life and also the workability such as cuttability and forgeability of the material.
    Type: Grant
    Filed: November 29, 2011
    Date of Patent: May 19, 2015
    Assignee: JFE STEEL CORPORATION
    Inventors: Yasumasa Hirai, Kiyoshi Uwai
  • Patent number: 8894779
    Abstract: Provided is bearing steel excellent in post spheroidizing-annealing workability and in post quenching-tempering hydrogen fatigue resistance property. The bearing steel has a chemical composition containing, by mass %: 0.85% to 1.10% C; 0.30% to 0.80% Si; 0.90% to 2.00% Mn; 0.025% or less P; 0.02% or less S; 0.05% or less Al; 1.8% to 2.5% Cr; 0.15% to 0.4% Mo; 0.0080% or less N; 0.0020% or less O; and the balance being Fe and incidental impurities, to thereby effectively suppress the generation of WEA even in environment where hydrogen penetrates into the steel, so as to improve the rolling contact fatigue life and also the workability such as cuttability and forgeability of the material.
    Type: Grant
    Filed: November 24, 2011
    Date of Patent: November 25, 2014
    Assignee: JFE Steel Corporation
    Inventors: Yasumasa Hirai, Kiyoshi Uwai
  • Publication number: 20130224065
    Abstract: Provided is bearing steel excellent in workability after spheroidizing-annealing and in hydrogen fatigue resistance property after quenching and tempering. The bearing steel has a chemical composition containing, by mass %: 0.85% to 1.10% C; 0.30% to 0.80% Si; 0.90% to 2.00% Mn; 0.025% or less P; 0.02% or less S; 0.05% or less Al; 1.8% to 2.5% Cr; 0.15% to 0.4% Mo; 0.0080% or less N; and 0.0020% or less O, which further contains more than 0.0015% to 0.0050% or less Sb, with the balance being Fe and incidental impurities, to thereby effectively suppress the generation of WEA even in environment where hydrogen penetrates into the steel, so as to improve the roiling contact fatigue life and also the workability such as cuttability and forgeability of the material.
    Type: Application
    Filed: November 29, 2011
    Publication date: August 29, 2013
    Applicant: JFE STEEL CORPORATION
    Inventors: Yasumasa Hirai, Kiyoshi Uwai
  • Publication number: 20130189147
    Abstract: Provided is bearing steel excellent in post spheroidizing-annealing workability and in post quenching-tempering hydrogen fatigue resistance property. The bearing steel has a chemical composition containing, by mass %: 0.85% to 1.10% C; 0.30% to 0.80% Si; 0.90% to 2.00% Mn; 0.025% or less P; 0.02% or less S; 0.05% or less Al; 1.8% to 2.5% Cr; 0.15% to 0.4% Mo; 0.0080% or less N; 0.0020% or less O; and the balance being Fe and incidental impurities, to thereby effectively suppress the generation of WEA even in environment where hydrogen penetrates into the steel, so as to improve the rolling contact fatigue life and also the workability such as cuttability and forgeability of the material.
    Type: Application
    Filed: November 24, 2011
    Publication date: July 25, 2013
    Applicant: JFE STEEL CORPORATION
    Inventors: Yasumasa Hirai, Kiyoshi Uwai
  • Patent number: 5952126
    Abstract: A polymer solid electrolyte that is useable in a lithium secondary cell comprising a polymer matrix, a polymerization initiator, an inorganic salt and a solvent. The polymer matrix is composed of a copolymer of a monomer having an amide group at a side chain and a polymer with an oxyethylene repeating unit. The polymer solid electrolyte has excellent conductivity and can easily be processed due to its good mechanical property.
    Type: Grant
    Filed: July 30, 1997
    Date of Patent: September 14, 1999
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Doo-yeon Lee, Sang-hyun Sung, Yasumasa Hirai, Seok-gwang Doo
  • Patent number: 5512194
    Abstract: There are provided acicular berthollide particles comprising crystalline particles expressed by the formula FeOx (1.33.ltoreq.x<1.5) and modified with a specific amount of zinc ions and a process producing the same which comprises the steps of oxidizing acicular magnetic iron oxide particles expressed by the formula FeOx (1.0<x<1.33) and modified with a specific amount of zinc ions which are produced by (a) heating and dehydrating acicular hydrous iron oxide particles containing a specific amount of a zinc component, reducing, and heating the particles under specific conditions, or (b) reducing acicular iron oxide particles containing a specific amount of a zinc component and heating the particles under specific conditions, or (c) heating acicular magnetic iron oxide particles expressed by the formula FeOx (1.0<x<1.33) containing a specific amount of zinc ions under specific conditions.
    Type: Grant
    Filed: June 7, 1994
    Date of Patent: April 30, 1996
    Assignee: Ishihara Sangyo Kaisha, Ltd.
    Inventors: Makoto Ogasawara, Masakazu Yada, Kaoru Sakurai, Kazuya Haga, Masahide Miyashita, Yasumasa Hirai