Patents by Inventor Tsunemi Wada

Tsunemi Wada 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: 4933024
    Abstract: A method for manufacturing a high strength rail with good toughness, comprises cooling a rail to Ar.sub.3 transformation point or less after hot rolling; heating said cooled rail at a temperature of an austenite temperature zone ranging from Ac.sub.3 transformation point to 950.degree. C.; and cooling the heated rail. The chemical composition of the rail consists of 0.50 to 0.85 wt. % C, 0.50 to 1.50 wt. % Mn, 0.035 wt. % S or less, 0.10 to 1.00 wt. % Si, 0.035 wt. % P or less, 0.050 wt. % Al or less and the balance of Fe and inevitable impurities.
    Type: Grant
    Filed: October 3, 1988
    Date of Patent: June 12, 1990
    Assignee: NKK Corporation
    Inventors: Kozo Fukuda, Tsunemi Wada, Ichiro Nakauchi, Shinichi Nagahashi, Yoshio Saito, Kiyotaka Morioka, Yuzuru Kataoka, Yuzu Kato, Toyokazu Teramoto, Akio Fujibayashi
  • Patent number: 4886558
    Abstract: A method for heat-treating a steel rail head, which comprises: heating a steel rail head to the austenization temperature; then, cooling the rail head by means of a hot water jet until a surface temperature of the rail head decreases to a temperature not below 420.degree. C.; and then cooling the rail head by means of an air jet at least to the pearlite transformation temperature, thereby transforming the structure of a surface portion of the rail head into a uniform and fine pearlite structure. The above-described method includes a method in which the rail head is previously cooled by means of a water spray until the surface temperature of the rail head decreases to a temperature not below 530.degree. C. prior to the cooling of the rail head by means of the above-mentioned hot water jet.
    Type: Grant
    Filed: May 20, 1988
    Date of Patent: December 12, 1989
    Assignee: NKK Corporation
    Inventors: Toyokazu Teramoto, Akio Fujibayashi, Kozo Fukuda, Mashiro Ueda, Shinichi Nagahashi, Yazuru Kataoka, Hiroaki Sato, Tsunemi Wada, Takao Gino, Yoshio Saito, Kiyotaka Morioka
  • Patent number: 4767475
    Abstract: A wear resistance rail which comprises 0.50 to 0.85 wt. % of C, 0.10 to 1.0 wt. % of Si, 0.50 to 1.50 wt. % of Mn, less than 0.035 wt. % of P, less than 0.035 wt. % of S, less than 0.050 wt. % of Al, and the balance of iron and impurities. The web has a high toughness tempered bainite structure, tempered martensite structure or a tempered mixed structure of bainite and martensite and the head rail has high wear resistance which prevents unstable destructive cracks from propagating. The rail can further contain one or more of 0.05 to 1.50 wt. % of Cr, 0.05 to 0.20 wt. % of Mo, 0.03 to 0.10 wt. % of V, 0.10 to 1.00 wt. % of Ni, and 0.005 to 0.050 wt. % of Nb.
    Type: Grant
    Filed: October 15, 1986
    Date of Patent: August 30, 1988
    Assignee: Nippon Kokan Kabushiki Kaisha
    Inventors: Kozo Fukuda, Tsunemi Wada, Shinichi Nagahashi, Yoshio Saito, Masahiro Ueda, Minoru Tanaka