Patents by Inventor Yuji SAKIYAMA

Yuji SAKIYAMA 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: 11904573
    Abstract: A hot-stamped article according to the present invention has a plating layer being attached to a single surface in an amount of 10 g/m2 or more and 90 g/m2 or less and having a Ni content of 10 mass % or more and 25 mass % or less with a remainder including Zn and impurities on a surface of a base steel sheet having a predetermined chemical composition, in a surface layer region, a metallographic structure includes 80.0% or more of martensite and 8.0% or more of residual austenite in terms of area percentage, and the concentration of Ni in the surface layer region is 8 mass % or more.
    Type: Grant
    Filed: May 28, 2020
    Date of Patent: February 20, 2024
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Yuji Sakiyama, Yuri Toda, Kazuo Hikida
  • Patent number: 11905581
    Abstract: A hot-stamped article according to the present invention has a plating layer being attached in an amount of 10 g/m2 or more and 90 g/m2 or less and having a Ni content of 10 mass % or more and 25 mass % or less with a remainder including Zn and an impurity on a surface of a base steel sheet having a predetermined chemical composition, a surface layer region includes 90.0% or more of martensite in terms of area percentage, and a concentration of Ni in a prior austenite grain boundary in the surface layer region is 5.5 mass % or more.
    Type: Grant
    Filed: May 28, 2020
    Date of Patent: February 20, 2024
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Yuji Sakiyama, Yuri Toda, Tomohito Tanaka, Kazuo Hikida
  • Publication number: 20230257844
    Abstract: Provided is a steel sheet comprising a sheet thickness center part and a first surface layer softened part and a second surface layer softened part respectively arranged at two sides of the sheet thickness center part, wherein the first surface layer softened part and second surface layer softened part have 10 ?m or more average thicknesses and have average Vickers hardnesses of 0.90 time or less of the average Vickers hardness of a sheet thickness ½ position, and the first surface layer softened part has an average Vickers hardness of 1.05 times or more the average Vickers hardness of the second surface layer softened part.
    Type: Application
    Filed: August 6, 2021
    Publication date: August 17, 2023
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Katsuya NAKANO, Yuji SAKIYAMA, Takashi YASUTOMI, Yoshiaki HONDA, Masahiro NAKATA
  • Publication number: 20230250521
    Abstract: Provided is a steel sheet comprising a sheet thickness center part and a first surface layer part and a second surface layer part respectively arranged at two sides of the sheet thickness center part, wherein the first surface layer part and second surface layer part respectively independently have thicknesses of more than 10 ?m to 30% or less of the sheet thickness, the first surface layer part and second surface layer part have average Vickers hardnesses different from the average Vickers hardness of a sheet thickness ½ position, and a first hardness cumulative value at a region from a surface of the first surface layer part side to 30% of the sheet thickness is 1.05 times or more of a second hardness cumulative value at a region from a surface of the second surface layer part side to 30% of the sheet thickness.
    Type: Application
    Filed: August 6, 2021
    Publication date: August 10, 2023
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Yuji SAKIYAMA, Takashi YASUTOMI, Katsuya NAKANO, Yoshiaki HONDA, Masahiro NAKATA
  • Publication number: 20230182190
    Abstract: This hot stamping member is a hot stamping member including a base material and a plating layer provided on the base material, in which the plating layer has a Ni-rich region, an Al-rich region and an Fe-rich region in this order from a surface of the plating layer, in a region from the surface of the plating layer to a 100 nm position in the thickness direction from the surface of the plating layer, Ni and Fe satisfy predetermined contents, in a region from the 100 nm position in the thickness direction from the surface of the plating layer to a 500 nm position in the thickness direction from the surface of the plating layer, Ni and Fe satisfy predetermined contents, and, in a region from the 500 nm position in the thickness direction from the surface of the plating layer to a 1000 nm position in the thickness direction from the surface of the plating layer, Ni and Fe satisfy predetermined contents.
    Type: Application
    Filed: May 13, 2021
    Publication date: June 15, 2023
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Akinobu KOBAYASHI, Yuji SAKIYAMA, Takayuki HARANO
  • Publication number: 20230093517
    Abstract: This steel sheet for hot stamping includes a base material, an Al-Si alloy plating layer in which the Al content is 75 mass% or more, the Si content is 3 mass% or more and the total of the Al content and the Si content is 95 mass% or more and a Ni plating layer in which the Ni content is more than 90 mass% in this order, the chemical composition of the base material is, by mass%, C: 0.01% or more and less than 0.70%, Si: 0.005% to 1.000%, Mn: 0.40% to 3.00%, Nb: 0.010% to 0.200%, a solid solution of Nb: 0.010% to 0.150%, sol. A1: 0.00020% to 0.50000%, P: 0.100% or less, S: 0.1000% or less, N: 0.0100% or less, Cu: 0% to 1.00%, Ni: 0% to 1.00%, V: 0% to 1.00%, Ti: 0% to 0.150%, Mo: 0% to 1.000%, Cr: 0% to 1.000%, B: 0% to 0.0100%, Ca: 0% to 0.010%. REM: 0% to 0.300%, and a remainder: Fe and an impurity, the Al-Si alloy plating layer has a thickness of 7 to 148 µm, and the Ni plating layer has a thickness of more than 200 nm and 2500 nm or less.
    Type: Application
    Filed: May 13, 2021
    Publication date: March 23, 2023
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Takayuki HARANO, Yuji SAKIYAMA, Akinobu KOBAYASHI
  • Publication number: 20230078655
    Abstract: This steel sheet for hot stamping includes a base material, an Al—Si alloy plating layer in which the Al content is 75 mass % or more, the Si content is 3 mass % or more and the total of the Al content and the Si content is 95 mass % or more, an Al oxide coating having a thickness of 0 to 20 nm and a Ni plating layer in which the Ni content is more than 90 mass % in this order, the base material has a predetermined chemical composition, the Al—Si alloy plating layer has a thickness of 7 to 148 ?m, and the Ni plating layer has a thickness of more than 200 nm and 2500 nm or less.
    Type: Application
    Filed: May 13, 2021
    Publication date: March 16, 2023
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Yuji SAKIYAMA, Akinobu KOBAYASHI, Takayuki HARANO
  • Publication number: 20220234330
    Abstract: A hot-stamped article according to the present invention has a plating layer being attached to a single surface in an amount of 10 g/m2 or more and 90 g/m2 or less and having a Ni content of 10 mass % or more and 25 mass % or less with a remainder including Zn and impurities on a surface of a base steel sheet having a predetermined chemical composition, in a surface layer region, a metallographic structure includes 80.0% or more of martensite and 8.0% or more of residual austenite in terms of area percentage, and the concentration of Ni in the surface layer region is 8 mass % or more.
    Type: Application
    Filed: May 28, 2020
    Publication date: July 28, 2022
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Yuji SAKIYAMA, Yuri TODA, Kazuo HIKIDA
  • Publication number: 20220227105
    Abstract: A steel sheet for hot stamping according to the present invention has a plating layer being attached in an amount of 10 g/m2 or more and 90 g/m2 or less and having a Ni content of 10 mass % or more and 25 mass % or less with a remainder including Zn and impurities on a surface of a base steel sheet having a predetermined chemical composition, in a surface layer region, 15.0% or more of the crystal grains of one or two kinds of unauto-tempered martensite and lower bainite are included in terms of area percentage, and the average dislocation density is 4×1015 m/m3.
    Type: Application
    Filed: May 28, 2020
    Publication date: July 21, 2022
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Yuji SAKIYAMA, Yuri TODA, Kazuo HIKIDA
  • Publication number: 20220228244
    Abstract: A hot-stamped article according to the present invention has a plating layer being attached in an amount of 10 g/m2 or more and 90 g/m2 or less and having a Ni content of 10 mass % or more and 25 mass % or less with a remainder including Zn and an impurity on a surface of a base steel sheet having a predetermined chemical composition, a surface layer region includes 90.0 % or more of martensite in terms of area percentage, and a concentration of Ni in a prior austenite grain boundary in the surface layer region is 5.5 mass % or more.
    Type: Application
    Filed: May 28, 2020
    Publication date: July 21, 2022
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Yuji SAKIYAMA, Yuri TODA, Tomohito TANAKA, Kazuo HIKIDA