Patents by Inventor Akimasa Kido

Akimasa Kido 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: 11085107
    Abstract: A steel sheet has a composition containing, by mass %, C: 0.04% to 0.20%, Si: 0.6% to 1.5%, Mn: 1.0% to 3.0%, P: 0.10% or less, S: 0.030% or less, Al: 0.10% or less, N: 0.010% or less, one, two, or all of Ti, Nb, and V in an amount of 0.01% to 1.0% each, and the balance being Fe and inevitable impurities, a microstructure including, in terms of area ratio, 50% or more of ferrite, in which an average grain diameter at a position located 50 ?m from a surface of the steel sheet in a thickness direction is 3000×(tensile strength TS (MPa))?0.85 ?m or less, C precipitates having a grain diameter of less than 20 nm formed in steel is 0.010 mass % or more, and a amount of precipitated Fe is 0.03 mass % to 1.0 mass %, and a roughness Ra of 3.0 ?m or less.
    Type: Grant
    Filed: December 13, 2016
    Date of Patent: August 10, 2021
    Assignee: JFE Steel Corporation
    Inventors: Taro Kizu, Akimasa Kido, Tetsushi Tadani
  • Patent number: 10815547
    Abstract: A high strength steel sheet having high strength such as a tensile strength of 780 MPa or more and having excellent blanking workability and stretch flangeability and a manufacturing method therefor are provided. A high strength steel sheet comprises: a chemical composition containing, in mass %, C: 0.05% to 0.30%, Si: 0.6% to 2.0%, Mn: 1.3% to 3.0%, P: 0.10% or less, S: 0.030% or less, Al: 2.0% or less, N: 0.010% or less, and one or more of Ti, Nb, and V: 0.01% to 1.0% each, with a balance being Fe and incidental impurities; a ferrite microstructure of 50% or more in area ratio; an amount of precipitated Fe of 0.04 mass % or more; and a precipitate with a particle size of less than 20 nm, wherein C* and C*p satisfy specific conditions.
    Type: Grant
    Filed: March 1, 2016
    Date of Patent: October 27, 2020
    Assignee: JFE STEEL CORPORATION
    Inventors: Taro Kizu, Shunsuke Toyoda, Akimasa Kido, Tetsushi Tadani
  • Patent number: 10526678
    Abstract: This disclosure provides a predetermined composition, where a conversion value C* of total carbon contents in Ti, Nb and V precipitates whose grain sizes are less than 20 nm is 0.010 mass % to 0.100 mass %, Fe content in Fe precipitates is 0.03 mass % to 0.50 mass %, and an average grain size of ferrite grains whose grain sizes are top 5 % large in ferrite grain size distribution of rolling direction cross section is (4000/TS)2 ?m or less, the TS indicating tensile strength in unit of MPa.
    Type: Grant
    Filed: July 5, 2016
    Date of Patent: January 7, 2020
    Assignee: JFE STEEL CORPORATION
    Inventors: Taro Kizu, Shunsuke Toyoda, Akimasa Kido, Tetsushi Tadani
  • Publication number: 20190309396
    Abstract: A steel sheet has a composition containing, by mass %, C: 0.04% to 0.20%, Si: 0.6% to 1.5%, Mn: 1.0% to 3.0%, P: 0.10% or less, S: 0.030% or less, Al: 0.10% or less, N: 0.010% or less, one, two, or all of Ti, Nb, and V in an amount of 0.01% to 1.0% each, and the balance being Fe and inevitable impurities, a microstructure including, in terms of area ratio, 50% or more of ferrite, in which an average grain diameter at a position located 50 ?m from a surface of the steel sheet in a thickness direction is 3000×(tensile strength TS (MPa))?0.85 ?m or less, C precipitates having a grain diameter of less than 20 nm formed in steel is 0.010 mass % or more, and a amount of precipitated Fe is 0.03 mass % to 1.0 mass %, and a roughness Ra of 3.0 ?m or less.
    Type: Application
    Filed: December 13, 2016
    Publication date: October 10, 2019
    Inventors: Taro Kizu, Akimasa Kido, Tetsushi Tadani
  • Publication number: 20180371574
    Abstract: This disclosure provides a predetermined composition, where a conversion value C* of total carbon contents in Ti, Nb and V precipitates whose grain sizes are less than 20 nm is 0.010 mass % to 0.100 mass %, Fe content in Fe precipitates is 0.03 mass % to 0.50 mass %, and an average grain size of ferrite grains whose grain sizes are top 5 % large in ferrite grain size distribution of rolling direction cross section is (4000/TS)2 ?m or less, the TS indicating tensile strength in unit of MPa.
    Type: Application
    Filed: July 5, 2016
    Publication date: December 27, 2018
    Applicant: JFE STEEL CORPORATION
    Inventors: Taro KIZU, Shunsuke TOYODA, Akimasa KIDO, Tetsushi TADANI
  • Publication number: 20180155806
    Abstract: This disclosure provides a predetermined composition, where a conversion value C* of total carbon contents in Ti, Nb and V precipitates whose grain sizes are less than 20 nm is 0.010 mass % to 0.100 mass %, Fe content in Fe precipitates is 0.03 mass % to 0.50 mass %, and an average grain size of ferrite grains whose grain sizes are top 5 % large in ferrite grain size distribution of rolling direction cross section is (4000/TS)2 ?m or less, the TS indicating tensile strength in unit of MPa.
    Type: Application
    Filed: July 5, 2016
    Publication date: June 7, 2018
    Applicant: JFE STEEL CORPORATION
    Inventors: Taro KIZU, Shunsuke TOYODA, Akimasa KIDO, Tetsushi TADANI
  • Publication number: 20180016657
    Abstract: A high strength steel sheet having high strength such as a tensile strength of 780 MPa or more and having excellent blanking workability and stretch flangeability and a manufacturing method therefor are provided. A high strength steel sheet comprises: a chemical composition containing, in mass %, C: 0.05% to 0.30%, Si: 0.6% to 2.0%, Mn: 1.3% to 3.0%, P: 0.10% or less, S: 0.030% or less, Al: 2.0% or less, N: 0.010% or less, and one or more of Ti, Nb, and V: 0.01% to 1.0% each, with a balance being Fe and incidental impurities; a ferrite microstructure of 50% or more in area ratio; an amount of precipitated Fe of 0.04 mass % or more; and a precipitate with a particle size of less than 20 nm, wherein C* and C*p satisfy specific conditions.
    Type: Application
    Filed: March 1, 2016
    Publication date: January 18, 2018
    Applicant: JFE STEEL CORPORATION
    Inventors: Taro KIZU, Shunsuke TOYODA, Akimasa KIDO, Tetsushi TADANI
  • Patent number: 5500290
    Abstract: A surface treated steel sheet comprises: a steel sheet containing C, Si, Mn, P, S, Ni, Ti, Cu and B; a diffused alloy layer containing Fe, Ni, and P; and a zinc coating layer formed on the diffused alloy layer.A method for producing a surface treated steel sheet comprises the steps of: preparing a steel sheet; coating the steel sheet with a Ni-P coating layer; heat-treating the steel sheet coated with the Ni-P coating layer; and forming a zinc coating layer on the diffused alloy layer.
    Type: Grant
    Filed: June 24, 1994
    Date of Patent: March 19, 1996
    Assignee: NKK Corporation
    Inventors: Satoru Udagawa, Masaki Abe, Satoru Ando, Yasuhiro Matsuki, Toyofumi Watanabe, Yukimitsu Shiohara, Masaya Morita, Akimasa Kido