Patents by Inventor Yasunobu Kunisada

Yasunobu Kunisada 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: 5403410
    Abstract: An abrasion-resistant steel consists essentially of 0.05 to 0.45 wt. % C, 0.1 to 1 wt. % Si, 0.1 to 2 wt. % Mn, 0.05 to 2 wt. % Nb and the balance being Fe and inevitable impurities, the steel includes at least 200 of precipitates of 15 .mu.m or more in particle size per 1 mm.sup.2 and the precipitates contains Nb.In addition to the above basic elements, at least one element selected from the group consisting of 0.1 to 2 wt. % Cu, 0.1 to 10 wt. % Ni, 0.1 to 3 wt. % Cr, 0.1 to 3 wt. % Mo and 0.0003 to 0.01 wt. % B or at least one element selected from the group consisting of 0.003 to 0.05 wt. % Ti and 0.01 to 1 wt. % V is added to steel.
    Type: Grant
    Filed: August 31, 1993
    Date of Patent: April 4, 1995
    Assignee: NKK Corporation
    Inventors: Nobuo Shikanai, Yasunobu Kunisada, Tetsuya Sanpei, Kazunori Yako, Kenji Hirabe
  • Patent number: 5393358
    Abstract: An abrasion-resistant steel having excellent surface property consists essentially of 0.1 to 0.45 wt. % C, 0.1 to 1 wt. % Si, 0.1 to 2 wt. % Mn, 0.04 wt. % or less P, 0.04 wt. % or less S, 0.1 to 1 wt. % Ti, 0.0015 to 0.01 wt. % N, and the balance being Fe and inevitable impurities, the steel including at least 400 TiC precipitates of 0.5 .mu.m or more in particle size per 1 mm.sup.2 and the steel having Ti* of 0.05 wt. % or more and less than 0.4 wt. % the Ti* being defined by the equations of Ti*=Ti(a)-[Ti], Ti(a)=Ti-{(48/14)N+(48/32)S}, log[Ti][C]=(-10580/T)+4.38, [Ti]=4.times.[C]+{Ti(a) -4.times.C}.A method for producing an abrasion-resistant steel having excellent surface property comprising the steps of: preparing a molten steel having the composition specified above; casting continuously the molten steel to produce slab, coarse particles of TiC being precipitated in the slab; hot-working the slab to produce a hot-rolled steel sheet at 1300.degree. C. or less; and quenching the hot-rolled steel sheet.
    Type: Grant
    Filed: July 28, 1993
    Date of Patent: February 28, 1995
    Assignee: NKK Corporation
    Inventors: Nobuo Shikanai, Tetsuya Sanpei, Kazunori Yako, Kenji Hirabe, Yasunobu Kunisada
  • Patent number: 5284529
    Abstract: An abrasion-resistant steel consists essentially of 0.05 to 0.45 wt. % C, 0.1 to 1 wt. % Si, 0.1 to 2 wt. % Mn, 0.05 to 1.5 wt. % Ti and the balance being Fe and inevitable impurities, the steel includes at least 200 of precipitates of 1 .mu.m or more in particle size per 1 mm.sup.2 and the precipitates contains Ti.In addition to the above basic elements, at least one element selected from the group consisting of 0.1 to 2 wt. % Cu, 0.1 to 10 wt. % Ni, 0.1 to 3 wt. % Cr, 0.1 to 3 wt. % Mo and 0.0003 to 0.01 wt. % B is added to steel or at least one element selected from the group consisting of 0.005 to 1 wt. % Nb and 0.01 to 1 wt. % V is added to steel.
    Type: Grant
    Filed: February 26, 1993
    Date of Patent: February 8, 1994
    Assignee: NKK Corporation
    Inventors: Nobuo Shikanai, Yasunobu Kunisada, Tetsuya Sanpei, Kazunori Yako, Kenji Hirabe
  • Patent number: 5236521
    Abstract: An abrasion resistant steel consisting essentially of 0.05 to 0.45 wt. % C, 0.1 to 1 wt. % Si, 0.1 to 2 wt. % Mn, 0.3 to 1.5 wt. % Ti, at most 0.005 wt. % N and the balance Fe as the basic elements contributing to the enhancement of the abrasion resistance property, without excessively increasing the hardness of the steel. In addition to the basic elements, at least one element selected from the group consisting of 0.1 to 2 wt. % Cu, 0.1 to 10 wt. % Ni, 0.1 to 3 wt. % Cr, 0.1 to 3 wt. % Mo and 0.0003 to 0.01 wt. % B may be added to enhance the quenching hardenability of the steel, and 0.01 to 0.5 wt. % V may be added to enhance the precipitation hardenability of the steel.
    Type: Grant
    Filed: June 15, 1992
    Date of Patent: August 17, 1993
    Assignee: NKK Corporation
    Inventors: Nobuo Shikanai, Tetsuya Sanpei, Kazunori Yako, Kenji Hirabe, Yasunobu Kunisada