Patents by Inventor Tatsumi Kimura

Tatsumi Kimura 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: 11492689
    Abstract: The rail having a chemical composition containing C: 0.70-1.00 mass %, Si: 0.50-1.60 mass %, Mn: 0.20-1.00 mass %, P: ?0.035 mass %, S: ?0.012 mass %, Cr: 0.40-1.30 mass %, where Ceq defined by the formula (1) is 1.04-1.25, Ceq=[% C]+([% Si]/11)+([% Mn]/7)+([% Cr]/5.8)??(1) where [% M] is the content in mass % of the element M, the balance being Fe and inevitable impurities, where Ceq(max) is ?1.40, where the Ceq(max) is determined by the formula (2) using maximum contents of C, Si, Mn, and Cr obtained by subjecting a region between specified positions to EPMA line analysis; and a pearlite area ratio in the region is 95% or more, Ceq(max)=[% C(max)]+([% Si(max)]/11)+([% Mn(max)]/7)+([% Cr(max)]/5.8)??(2) where [% M(max)] is the maximum content of the element M.
    Type: Grant
    Filed: March 28, 2019
    Date of Patent: November 8, 2022
    Assignee: JFE STEEL CORPORATION
    Inventors: Keisuke Ando, Tatsumi Kimura, Satoshi Igi
  • Patent number: 11401591
    Abstract: A method for selecting a rail steel and a wheel steel comprising: selecting a rail steel and a wheel steel to be used as a rail and a wheel on an actual track, respectively, the rail steel and the wheel steel having a specific chemical composition, such that the rail comprises a head portion having a yield strength YSR of 830 MPa or more, the wheel comprises a rim portion having a yield strength YSW of 580 MPa or more, and a ratio YSR/YSW of the yield strength YSR at the head portion of the rail to the yield strength YSW at the rim portion of the wheel falls within a range of: 0.85?YSR/YSW?1.95 (1).
    Type: Grant
    Filed: December 14, 2016
    Date of Patent: August 2, 2022
    Assignee: JFE STEEL CORPORATION
    Inventors: Minoru Honjo, Tatsumi Kimura, Katsuyuki Ichimiya, Kazukuni Hase
  • Patent number: 11111555
    Abstract: A rail achieves a high 0.2% proof stress after straightening treatment, the high 0.2% proof stress being effective at improving rolling contact fatigue resistance of the rail, by hot rolling a steel raw material to obtain a rail, the steel raw material having a chemical composition containing C: 0.70% to 0.85%, Si: 0.1% to 1.5%, Mn: 0.4% to 1.5%, P: 0.035% or less, S: 0.010% or less, and Cr: 0.05% to 1.50% with the balance being Fe and inevitable impurities; straightening the rail with a load of 50 tf or more; and subsequently subjecting the rail to heat treatment in which the rail is held in a temperature range of 150° C. or more and 400° C. or less for 0.5 hours or more and 10 hours or less.
    Type: Grant
    Filed: March 20, 2018
    Date of Patent: September 7, 2021
    Assignee: JFE STEEL CORPORATION
    Inventors: Minoru Honjo, Tatsumi Kimura, Katsuyuki Ichimiya, Kazukuni Hase
  • Publication number: 20210102277
    Abstract: The rail having a chemical composition containing C: 0.70-1.00 mass %, Si: 0.50-1.60 mass %, Mn: 0.20-1.00 mass %, P: ?0.035 mass %, S: ?0.012 mass %, Cr: 0.40-1.30 mass %, where Ceq defined by the formula (1) is 1.04-1.25, Ceq=[% C]+([% Si]/11)+([% Mn]/7)+([% Cr]/5.8) ??(1) where [% M] is the content in mass % of the element M, the balance being Fe and inevitable impurities, where Ceq(max) is ?1.40, where the Ceq(max) is determined by the formula (2) using maximum contents of C, Si, Mn, and Cr obtained by subjecting a region between specified positions to EPMA line analysis,; and a pearlite area ratio in the region is 95% or more, Ceq(max)=[% C(max)]+([% Si(max)]/11)+([% Mn(max)]/7)+([% Cr(max)]/5.8) ??(2) where [% M(max)] is the maximum content of the element M.
    Type: Application
    Filed: March 28, 2019
    Publication date: April 8, 2021
    Applicant: JFE STEEL CORPORATION
    Inventors: Keisuke ANDO, Tatsumi KIMURA, Satoshi IGI
  • Publication number: 20210025043
    Abstract: The rail having a chemical composition containing C: 0.70-0.85 mass %, Si: 0.50-1.60 mass %, Mn: 0.20-1.00 mass %, P: 0.035 mass % or less, S: 0.012 mass % or less, Cr: 0.40-1.30 mass %, the chemical composition satisfying the formula (1) 0.30?[% Si]/10+[% Mn]/6+[% Cr]/3?0.55??(1) where [% M] is the content in mass % of the element M, the balance being Fe and inevitable impurities, where Vickers hardness of a region between positions where a depth from a surface of a rail head of 0.5 and 25 mm is ?370 HV and <520 HV, a total area ratio of a pearlite microstructure and a bainite microstructure in the region is ?98%, and an area ratio of the bainite microstructure in the region is >5% and <20%.
    Type: Application
    Filed: March 28, 2019
    Publication date: January 28, 2021
    Applicant: JFE STEEL CORPORATION
    Inventors: Keisuke ANDO, Tatsumi KIMURA, Satoshi IGI
  • Publication number: 20200277682
    Abstract: A rail achieves a high 0.2% proof stress after straightening treatment, the high 0.2% proof stress being effective at improving rolling contact fatigue resistance of the rail, by hot rolling a steel raw material to obtain a rail, the steel raw material having a chemical composition containing C: 0.70% to 0.85%, Si: 0.1% to 1.5%, Mn: 0.4% to 1.5%, P: 0.035% or less, S: 0.010% or less, and Cr: 0.05% to 1.50% with the balance being Fe and inevitable impurities; straightening the rail with a load of 50 tf or more; and subsequently subjecting the rail to heat treatment in which the rail is held in a temperature range of 150° C. or more and 400° C. or less for 0.5 hours or more and 10 hours or less.
    Type: Application
    Filed: March 20, 2018
    Publication date: September 3, 2020
    Applicant: JFE Steel Corporation
    Inventors: Minoru HONJO, Tatsumi KIMURA, Katsuyuki ICHIMIYA, Kazukuni HASE
  • Publication number: 20200002780
    Abstract: A rail exhibits a high 0.2% proof stress after shipping, which is effective for improving rolling contact fatigue resistance of the rail, the rail having a chemical composition containing C: 0.70% to 0.85%, Si: 0.1% to 1.5%, Mn: 0.4% to 1.5%, P: 0.035% or less, S: 0.010% or less, and Cr: 0.05% to 1.50%, with the balance being Fe and inevitable impurities, and exhibiting, at least 90 days after a preparation date of a steel material inspection certificate of the rail which describes at least a measurement result of a 0.2% proof stress of a head of the rail, an improvement margin of a 0.2% proof stress of 40 MPa or more, relative to the 0.2% proof stress described in the steel material inspection certificate.
    Type: Application
    Filed: March 20, 2018
    Publication date: January 2, 2020
    Applicant: JFE STEEL CORPORATION
    Inventors: Minoru HONJO, Tatsumi KIMURA, Katsuyuki ICHIMIYA, Kazukuni HASE
  • Publication number: 20190338402
    Abstract: A method for manufacturing a railway vehicle wheel is provided. The method comprises: in an electric heating furnace or converter, preparing steel containing, in mass %. 0.65% to 0.84% of C, 0.1% to 1.5% of Si, 0.05% to 1.5% of Mn, 0.025% or less of P, 0.015% or less of S, 0.001% to 0.08% of Al, and 0.05% to 1.5% of Cr, the balance being Fe and incidental impurities; casting the steel to obtain a material; hot rolling and/or hot forging the material to form a wheel; heating the wheel to Ac3 point +50° C. or higher; cooling the wheel from a start temperature of 700° C. or higher to a stop temperature of 500° C. to 650° C. at a rate of 1° C./s to 10° C./s; and then air cooling the wheel.
    Type: Application
    Filed: July 22, 2019
    Publication date: November 7, 2019
    Applicant: JFE STEEL CORPORATION
    Inventors: Tatsumi KIMURA, Takashi IWAMOTO, Shigeru ENDO, Minoru HONJO, Katsuyuki ICHIMIYA, Kazukuni HASE, Kazuya TOKUNAGA
  • Publication number: 20190249280
    Abstract: A method for selecting a rail steel and a wheel steel comprising: selecting a rail steel and a wheel steel to be used as a rail and a wheel on an actual track, respectively, the rail steel and the wheel steel having a specific chemical composition, such that the rail comprises a head portion having a yield strength YSR of 830 MPa or more, the wheel comprises a rim portion having a yield strength YSW of 580 MPa or more, and a ratio YSR/YSW of the yield strength YSR at the head portion of the rail to the yield strength YSW at the rim portion of the wheel falls within a range of: 0.85?YSR/YSW?1.95 (1).
    Type: Application
    Filed: December 14, 2016
    Publication date: August 15, 2019
    Applicant: JFE STEEL CORPORATION
    Inventors: Minoru HONJO, Tatsumi KIMURA, Katsuyuki ICHIMIYA, Kazukuni HASE
  • Patent number: 10253397
    Abstract: A pearlitic rail includes a composition including in % by mass: 0.70% to 0.90% of C; 0.1% to 1.5% of Si; 0.01% to 1.5% of Mn; 0.001% to 0.035% of P; 0.0005% to 0.030% of S; 0.1% to 2.0% of Cr, remainder of the composition consisting of Fe and inevitable impurities. Surface hardness of a rail top is not less than HB 430, and hardness at a depth of 25 mm from a surface of the rail top is not less than HB 410.
    Type: Grant
    Filed: March 25, 2014
    Date of Patent: April 9, 2019
    Assignee: JFE Steel Corporation
    Inventors: Tatsumi Kimura, Kiyoshi Uwai, Shigeru Endo, Moriyasu Yamaguchi
  • Patent number: 10100380
    Abstract: A rail cooling device configured to forcibly cool a rail by jetting a coolant includes a porous plate nozzle including a plurality of nozzle holes configured to jet the coolant to an underside of the base of the rail to cool the underside of the base of the rail. Ends in a width direction of the porous plate nozzle correspond to ends of the underside of the base of the rail. Nozzle holes of the porous plate nozzle at the ends of the width direction are smaller than nozzle holes of the porous plate nozzle at a central part in the width direction, and a maximum value of a distance between centers of the nozzle holes at both ends in the width direction is 30% or more of a width of the underside of the base.
    Type: Grant
    Filed: May 3, 2018
    Date of Patent: October 16, 2018
    Assignee: JFE STEEL CORPORATION
    Inventors: Ryo Matsuoka, Makoto Nakaseko, Rinya Kojo, Tomoo Horita, Hideki Takahashi, Yoshikazu Yoshida, Tatsumi Kimura, Mineyasu Takemasa, Yuzuru Kataoka
  • Publication number: 20180251866
    Abstract: A rail cooling device configured to forcibly cool a rail by jetting a coolant includes a porous plate nozzle including a plurality of nozzle holes configured to jet the coolant to an underside of the base of the rail to cool the underside of the base of the rail. Ends in a width direction of the porous plate nozzle correspond to ends of the underside of the base of the rail. Nozzle holes of the porous plate nozzle at the ends of the width direction are smaller than nozzle holes of the porous plate nozzle at a central part in the width direction, and a maximum value of a distance between centers of the nozzle holes at both ends in the width direction is 30% or more of a width of the underside of the base.
    Type: Application
    Filed: May 3, 2018
    Publication date: September 6, 2018
    Applicant: JFE STEEL CORPORATION
    Inventors: Ryo MATSUOKA, Makoto NAKASEKO, Rinya KOJO, Tomoo HORITA, Hideki TAKAHASHI, Yoshikazu YOSHIDA, Tatsumi KIMURA, Mineyasu TAKEMASA, Yuzuru KATAOKA
  • Patent number: 9988696
    Abstract: A rail cooling method for forcibly cooling a rail by jetting a coolant includes jetting the coolant to a foot back part of the rail from a porous plate nozzle in which a nozzle hole at an end in a width direction is smaller than a nozzle hole at a central part in the width direction and causes a cooling capacity for the end in the width direction of the underside of the base of the rail to be lower than a cooling capacity for the central part in the width direction of the underside of the base of the rail.
    Type: Grant
    Filed: February 1, 2013
    Date of Patent: June 5, 2018
    Assignee: JFE STEEL CORPORATION
    Inventors: Ryo Matsuoka, Makoto Nakaseko, Rinya Kojo, Tomoo Horita, Hideki Takahashi, Yoshikazu Yoshida, Tatsumi Kimura, Mineyasu Takemasa, Yuzuru Kataoka
  • Publication number: 20170191149
    Abstract: Provided is a railway vehicle wheel that enables further reducing wear and fatigue damage of the wheel and rail in total. A railway vehicle wheel containing, in mass %: 0.65% to 0.84% of C; 0.1% to 1.5% of Si; 0.05% to 1.5% of Mn; 0.025% or less of P; 0.015% or less of S; 0.001% to 0.08% of Al; and 0.05% to 1.5% of Cr, the balance being Fe and incidental impurities, wherein a microstructure at least in a region extending from a tread to a depth of 15 mm is a pearlite structure, and a pearlite lamellar spacing at least in the region is 150 nm or less.
    Type: Application
    Filed: June 9, 2015
    Publication date: July 6, 2017
    Applicant: JFE STEEL CORPORATION
    Inventors: Tatsumi KIMURA, Takashi IWAMOTO, Shigeru ENDO, Minoru HONJO, Katsuyuki ICHIMIYA, Kazukuni HASE, Kazuya TOKUNAGA
  • Publication number: 20170101692
    Abstract: Provided is a rail that exhibits excellent wear resistance and reduced hardness variation in a rail length direction. The rail has a chemical composition containing 0.60% to 1.0% of C, 0.1% to 1.5% of Si, 0.01% to 1.5% of Mn, 0.035% or less of P, 0.030% or less of S, and 0.1% to 2.0% of Cr, the balance being Fe and incidental impurities. Surface hardness of the rail exhibits variation of ±HB 15 points or less in the rail length direction.
    Type: Application
    Filed: March 24, 2015
    Publication date: April 13, 2017
    Applicant: JFE STEEL CORPORATION
    Inventors: Tatsumi Kimura, Yukio Takashima
  • Publication number: 20160083820
    Abstract: A pearlitic rail includes a composition including in % by mass: 0.70% to 0.90% of C; 0.1% to 1.5% of Si; 0.01% to 1.5% of Mn; 0.001% to 0.035% of P; 0.0005% to 0.030% of S; 0.1% to 2.0% of Cr, remainder of the composition consisting of Fe and inevitable impurities. Surface hardness of a rail top is not less than HB 430, and hardness at a depth of 25 mm from a surface of the rail top is not less than HB 410.
    Type: Application
    Filed: March 25, 2014
    Publication date: March 24, 2016
    Applicant: JFE STEEL CORPORATION
    Inventors: Tatsumi Kimura, Kiyoshi Uwai, Shigeru Endo, Moriyasu Yamaguchi
  • Patent number: 9139887
    Abstract: The present invention provides bearing steel, comprising a chemical composition including by mass %, C: 0.56%?[% C]?0.70%, Si: 0.15%?[% Si]<0.50%, Mn: 0.60%?[% Mn]?1.50%, Cr: 0.50%?[% Cr]?1.10%, Mo: 0.05%?[% Mo]?0.5%, P: [% P]?0.025%, S: [% S]?0.025%, Al: 0.005%?[% Al]?0.500%, O: [% O]?0.0015%, N: 0.0030%?[% N]?0.015%, and remainder as Fe and incidental impurities.
    Type: Grant
    Filed: May 24, 2011
    Date of Patent: September 22, 2015
    Assignees: JFE STEEL CORPORATION, NTN CORPORATION
    Inventors: Minoru Honjo, Kazukuni Hase, Tatsumi Kimura, Shinji Mitao
  • Publication number: 20150152516
    Abstract: A pearlite rail contains, by % by mass, 0.70 to 1.0% C, 0.1 to 1.5% Si, 0.01 to 1.5% Mn, 0.001 to 0.035% P, 0.0005 to 0.030% S, and 0.1 to 2.0% Cr by mass with the balance being Fe and inevitable impurities, wherein a ?+? temperature range is 100° C. or lower.
    Type: Application
    Filed: April 25, 2012
    Publication date: June 4, 2015
    Applicant: JFE Steel Corporation
    Inventors: Tatsumi Kimura, Minoru Honjo, Shinji Mitao, Mineyasu Takemasa, Ryo Matsuoka, Yuzuru Kataoka
  • Publication number: 20150027599
    Abstract: A rail cooling method for forcibly cooling a rail by jetting a coolant includes jetting the coolant to a foot back part of the rail from a porous plate nozzle in which a nozzle hole at an end in a width direction is smaller than a nozzle hole at a central part in the width direction and causes a cooling capacity for the end in the width direction of the underside of the base of the rail to be lower than a cooling capacity for the central part in the width direction of the underside of the base of the rail.
    Type: Application
    Filed: February 1, 2013
    Publication date: January 29, 2015
    Inventors: Ryo Matsuoka, Makoto Nakaseko, Rinya Kojo, Tomoo Horita, Hideki Takahashi, Yoshikazu Yoshida, Tatsumi Kimura, Mineyasu Takemasa, Yuzuru Kataoka
  • Publication number: 20130174945
    Abstract: The present invention provides bearing steel, comprising a chemical composition including by mass %, C: 0.56%?[% C]?0.70%, Si: 0.15%?[% Si]<0.50%, Mn: 0.60%?[% Mn]?1.50%, Cr: 0.50%?[% Cr]?1.10%, Mo: 0.05%?[% Mo]?0.5%, P: [% P]?0.025%, S: [% S]?0.025%, Al: 0.005%?[% Al]?0.500%, O: [% O]?0.0015%, N: 0.0030%?[% N]?0.015%, and remainder as Fe and incidental impurities.
    Type: Application
    Filed: May 24, 2011
    Publication date: July 11, 2013
    Applicants: NTN CORPORATION, JFE STEEL CORPORATION
    Inventors: Minoru Honjo, Kazukuni Hase, Tatsumi Kimura, Shinji Mitao