Patents by Inventor Shohei YABU

Shohei YABU 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: 11365465
    Abstract: A steel sheet includes a predetermined chemical composition, and includes a steel microstructure represented by, in an area ratio, ferrite: 5% to 80%, a hard microstructure constituted of bainite, martensite or retained austenite or an arbitrary combination of the above: 20% to 95%, and a standard deviation of a line fraction of the hard microstructure on a line in a plane perpendicular to a thickness direction: 0.050 or less in a depth range where a depth from a surface when a thickness of a steel sheet is set as t is from 3t/8 to t/2.
    Type: Grant
    Filed: August 8, 2017
    Date of Patent: June 21, 2022
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Shohei Yabu, Akihiro Uenishi, Koutarou Hayashi
  • Publication number: 20220145415
    Abstract: The present invention relates to a cold rolled steel sheet containing C: 0.15% or more and 0.40% or less, Si: 0.50% or more and 4.00% or less, Mn: 1.00% or more and 4.00% or less, and sol. Al: 0.001% or more and 2.000% or less, having a metallic structure consisting of 35 to 65 area % of ferrite phases, 35 to 65 area % of hard second phases, and 0 to 5 area % of remaining phases, wherein 60% or more of the ferrite phases are recrystallized ferrite phases, an average crystal grain size defined by 15° grain boundaries is 5.0 ?m or less, a maximum connecting rate of the hard second phases is 10% or more, and a two-dimensional isoperimetric constant of the hard second phases is 0.20 or less.
    Type: Application
    Filed: March 31, 2020
    Publication date: May 12, 2022
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Shohei YABU, Koutarou HAYASHI, Akihiro UENISHI
  • Publication number: 20220090228
    Abstract: A hot-rolled steel sheet according to the present invention includes, as a chemical composition, by mass %: C: 0.030% to 0.250%; Si: 0.05% to 2.50%; Mn: 1.00% to 4.00%; Sol. Al: 0.001% to 2.000%; P: 0.100% or less; S: 0.0200% or less; N: 0.01000% or less; Ti: 0% to 0.20%; Nb: 0% to 0.20; B: 0% to 0.010%; V: 0% to 1.0%; Cr: 0% to 1.0%; Mo: 0% to 1.0%; Cu: 0% to 1.0%; Co: 0% to 1.0%; W: 0% to 1.0%; Ni: 0% to 1.0%; Ca: 0% to 0.01%; Mg: 0% to 0.01%; REM: 0% to 0.01%; Zr: 0% to 0.01%; and a remainder consisting of Fe and impurities, in which an area ratio of a scale damage portion, which is a portion lower than an average height of a surface of the steel sheet by 10 ?m or more, is 20% or less, and a tensile strength of the hot-rolled steel sheet is 780 MPa or more.
    Type: Application
    Filed: March 5, 2020
    Publication date: March 24, 2022
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Genki ABUKAWA, Hiroshi SHUTO, Kenta MORISAWA, Shohei YABU
  • Publication number: 20210404040
    Abstract: A hot-rolled steel sheet includes, as chemical composition, C, Si, Mn, and sol.Al. In the hot-rolled steel sheet, a sum of an average of pole densities in a crystal orientation group consisting of {211}<111> to {111}<112> and a pole density in a crystal orientation of {110}<001> is 0.5 to 6.0 in the surface region, and the tensile strength is 780 to 1370 MPa.
    Type: Application
    Filed: November 20, 2019
    Publication date: December 30, 2021
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Genki ABUKAWA, Shohei YABU
  • Publication number: 20210002741
    Abstract: A steel sheet including, in mass %, C: 0.05% or more and 0.30% or less, Si: 0.05% or more and 6.00% or less, Mn: 1.50% or more and 10.00% or less, and the balance: Fe and impurities, a steel sheet structure is composed of, in area ratio, 15% or more and 80% or less of ferrite and 20% or more and 85% or less in total of a hard structure composed of any one of bainite, martensite, or retained austenite, or any combination thereof, and to a steel sheet thickness t, an area ratio of a maximum coupled ferrite region in a region from a t/2 position at the steel sheet thickness center to a position at a depth of 3t/8 from a surface is 80% or more in area ratio to a total ferrite area, and a two-dimensional isoperimetric constant of the maximum coupled ferrite region is 0.35 or less.
    Type: Application
    Filed: March 30, 2018
    Publication date: January 7, 2021
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Shohei YABU, Koutarou HAYASHI, Akihiro UENISHI
  • Publication number: 20200071801
    Abstract: A high strength steel sheet containing a large amount of Mn which has bendability suitable as a material for auto part use and a method of producing the same are provided. A high strength steel sheet comprising a center part in a sheet thickness and a softened surface layer part on one surface or both surfaces of the center part in the sheet thickness, characterized in that, the center part in the sheet thickness has an average Mn concentration of greater than 4.0 mass % and less than 10.0 mass %, each softened surface layer part has a thickness of 0.1% to 30% of the sheet thickness, and the softened surface layer part has an average Mn concentration of 2.5 mass % or less, a recrystallization rate of 90% or more, and recrystallized structures with an average crystal grain size of 0.1 ?m or more and 40 ?m or less.
    Type: Application
    Filed: April 27, 2018
    Publication date: March 5, 2020
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Shohei YABU, Koutarou HAYASHI, Genki ABUKAWA, Akihiro UENISHI
  • Publication number: 20190144966
    Abstract: A steel sheet includes a predetermined chemical composition, and includes a steel microstructure represented by, in an area ratio, ferrite: 5% to 80%, a hard microstructure constituted of bainite, martensite or retained austenite or an arbitrary combination of the above: 20% to 95%, and a standard deviation of a line fraction of the hard microstructure on a line in a plane perpendicular to a thickness direction: 0.050 or less in a depth range where a depth from a surface when a thickness of a steel sheet is set as t is from 3t/8 to t/2.
    Type: Application
    Filed: August 8, 2017
    Publication date: May 16, 2019
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Shohei YABU, Akihiro UENISHI, Koutarou HAYASHI