Patents by Inventor Jun Maki

Jun Maki 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).

  • Publication number: 20230088501
    Abstract: A hot stamped body comprising a steel base material and an Al—Zn—Mg-based plating layer formed on a surface of the steel base material, wherein the plating layer has a predetermined chemical composition, the plating layer comprises an interfacial layer positioned at an interface with the steel base material and containing Fe and Al and a main layer positioned on the interfacial layer, the main layer comprises, by area ratio, 10.0 to 90.0% of an Mg—Zn containing phase, 5.0 to less than 30.0% of an Fe—Al containing phase, and 2.0 to 25.0% of an Al—Si containing oxide phase, the Mg—Zn containing phase comprises at least one selected from the group consisting of an MgZn phase, Mg2 Zn3 phase, and MgZn2 phase, and the Fe—Al containing phase comprises at least one of an FeAl phase and Fe—Al—Zn phase.
    Type: Application
    Filed: February 27, 2020
    Publication date: March 23, 2023
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Takuya MITSUNOBU, Takehiro TAKAHASHI, Jun MAKI
  • Patent number: 11584981
    Abstract: A plated steel sheet having excellent post-coating corrosion resistance includes: a steel; and a plating layer that is provided on a surface of the steel, in which the plating layer includes, by mass %, Al: 5.00% to 35.00%, Mg: 2.50% to 13.00%, Fe: 5.00% to 35.00%, Si: 0% to 2.00%, Ca: 0% to 2.00%, and a remainder consisting of Zn and impurities, and in a cross section of the plating layer, the area fraction of a Fe2Al5 phase is 5.0% to 60.0%, the area fraction of an eutectic structure of Zn and MgZn2 is 10.0% to 80.0%, the area fraction of a massive MgZn2 phase is 5.0% to 40.0%, and the area fraction of a remainder is 10.0% or less.
    Type: Grant
    Filed: April 16, 2020
    Date of Patent: February 21, 2023
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Takuya Mitsunobu, Jun Maki, Hiroshi Takebayashi, Takehiro Takahashi, Kohei Tokuda
  • Publication number: 20230033301
    Abstract: A non-oriented electrical steel sheet according to one embodiment of the present invention includes a base metal steel sheet, and a composite coating film composed of a Zn-containing phosphate and an organic resin, the composite coating film being formed on a surface of the base metal steel sheet, wherein: a content of Zn in the composite coating film is 10 mg/m2 or more per side; and the product of an amount of oxygen in the base metal steel sheet and a sheet thickness of the base metal steel sheet is 50 ppm·mm or less.
    Type: Application
    Filed: November 20, 2020
    Publication date: February 2, 2023
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Hiroyasu FUJII, Jun MAKI, Kazutoshi TAKEDA, Akira AKAGI, Hiroyuki MIMURA
  • Patent number: 11535916
    Abstract: An aluminum-based plated steel sheet according to an aspect of the present invention includes: a base material; an aluminum-based plating layer located above the base material; and an intermetallic compound layer that is located between the base material and the aluminum-based plating layer and contains an intermetallic compound of Al and Fe, in which the base material has a chemical component within a predetermined range, the aluminum-based plating layer contains, on average, 80 mass % or more and 97 mass % or less of Al, 3 mass % or more and 15 mass % or less of Si, 0 mass % or more and 5 mass % or less of Zn, 0 mass % or more and 5 mass % or less of Fe, 0 mass % or more and 3 mass % or less in total of one or more selected from the group consisting of Mg and Ca, and impurities so that a total amount thereof is 100 mass %, an average value of a thickness of the intermetallic compound layer is 2 ?m or more and 10 ?m or less, a maximum value of the thickness of the intermetallic compound layer is 10 ?m or mor
    Type: Grant
    Filed: December 5, 2018
    Date of Patent: December 27, 2022
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Soshi Fujita, Yuki Suzuki, Masahiro Fuda, Jun Maki, Hideaki Irikawa, Takashi Aramaki, Tatsuya Kubota
  • Publication number: 20220402015
    Abstract: To solve a problem about warpage of a steel sheet due to a difference in temperature raising rate between an overlapped part and a one-sheet part. This manufacturing method includes: a step of heating an overlapped blank; a step of transferring the heated overlapped blank; and a step of performing presswork on the heated overlapped blank by using a die, in which in the heating step, when sheet thicknesses of the first and second steel sheets are set to t1 and t2, respectively, and an average heating rate at a sheet temperature from 20 to 800° C. of a portion with a total sheet thickness (t1+t2) of an overlapped portion, and that of a non-overlapped portion are set to V and v1, respectively, the total sheet thickness (t1+t2) is 2.5 to 5.
    Type: Application
    Filed: February 24, 2021
    Publication date: December 22, 2022
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Soshi FUJITA, Yuki SUZUKI, Masahiro FUDA, Hideaki IRIKAWA, Jun MAKI, Nobuo YOSHIKAWA, Naruhiko NOMURA
  • Patent number: 11530474
    Abstract: Fe-Al-based plated hot-stamped member exhibiting excellent formed part corrosion resistance and post-coating corrosion resistance and manufacturing method. The hot-stamping member includes Fe-Al-based plated layer on one or both surfaces of a base material, the base material has a predetermined steel component, Fe-Al-based plated layer has a thickness of 10 ?m or more and 60 ?m or less, formed by A, B, C and D layers sequentially from a surface toward the base material, and each of the four layers is a Fe-Al-based intermetallic compound containing Al, Fe, Si, Mn and Cr for predetermined contents with the balance made up of impurities, the D layer further contains Kirkendall voids each of which cross-sectional area is 3 ?m2-30 ?m2 for 10 pieces/6000 ?m2 or more and 40 pieces/6000 ?m2 or less.
    Type: Grant
    Filed: February 15, 2019
    Date of Patent: December 20, 2022
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Soshi Fujita, Yuki Suzuki, Masahiro Fuda, Jun Maki, Hideaki Irikawa, Tatsuya Kubota
  • Publication number: 20220356547
    Abstract: A hot-dip coated steel product including: a steel product; and a coating layer including a Zn—Al—Mg alloy layer disposed on a surface of the steel product, in which the Zn—Al—Mg alloy layer includes a Zn phase, an Al phase, and a MgZn2 phase, and contains a Mg—Sn intermetallic compound phase in the Zn phase, and the coating layer has a chemical composition satisfying a predetermined average composition, a total area proportion of the Al phase and the MgZn2 phase is 70% or more, an area proportion of the Zn phase is 30% or less, an average value of cumulative circumferential lengths of the Al phase is less than 88 mm/mm2, and a total frequency in number of the Al phase having a circumferential length of 50 ?m or more is less than 100.
    Type: Application
    Filed: April 16, 2020
    Publication date: November 10, 2022
    Inventors: Kohei TOKUDA, Mamoru SAITO, Jun MAKI, Takuya MITSUNOBU, Yasuto GOTO
  • Publication number: 20220316022
    Abstract: A non-oriented electrical steel sheet according to one embodiment of this invention includes a base metal steel sheet and a composite coating film composed of a Zn-containing phosphate and an organic resin, the composite coating film being formed on a surface of the base metal steel sheet. A molar ratio of Zn to all metal components in the composite coating film is 10 mol % or more, and after the non-oriented electrical steel sheet is boiled for 20 minutes in boiled distilled water, an amount of soluble Zn in the distilled water is 1.0 mg/m2 or more. The method for determining the amount of soluble Zn is in accordance with JIS K 0102: 2016 “Testing Methods for Industrial Wastewater”, 53.3 “ICP Emission Spectroscopy”.
    Type: Application
    Filed: April 17, 2020
    Publication date: October 6, 2022
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Hiroyasu FUJII, Jun MAKI, Kazutoshi TAKEDA, Hiroyuki MIMURA, Yusuke KANTO, Shuichi YAMAZAKI
  • Patent number: 11364707
    Abstract: To solve the problem about the difference in temperature increasing rate between an overlapped part and a one-sheet part so as to further improve the corrosion resistance of plating after hot stamping.
    Type: Grant
    Filed: April 5, 2019
    Date of Patent: June 21, 2022
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Soshi Fujita, Yuki Suzuki, Masahiro Fuda, Jun Maki, Hideaki Irikawa, Masahiro Nakata
  • Publication number: 20220152983
    Abstract: A plated steel includes: a steel; and a plating layer that is provided on a surface of the steel, in which the plating layer includes, by mass %, Al: 5.00% to 35.00%, Mg: 2.50% to 13.00%. Fe: 5.00% to 40.00%, Si: 0% to 2.00%, Ca: 0% to 2.00%, and a remainder of Zn and impurities, and in a cross section of the plating layer, the area fraction of a Zn solid-solution Fe2Al5 phase in which 5% or more of Zn is solid-soluted is 10% to 60% and the area fraction of a MgZn2 phase is 10% to 90%.
    Type: Application
    Filed: April 16, 2020
    Publication date: May 19, 2022
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Takuya MITSUNOBU, Jun MAKI, Hiroshi TAKEBAYASHI, Takehiro TAKAHASHI, Kohei TOKUDA
  • Publication number: 20220145425
    Abstract: A plated steel sheet includes: a steel sheet; and a plating layer that is formed on at least a part of a surface of the steel sheet, in which a chemical composition of the plating layer includes, by mass %, Al: more than 5.00% and 35.00% or less, Mg: 3.00% to 15.00%, Si: 0% to 2.00%, Ca: 0% to 2.00%, and a remainder of Zn and impurities, in which in a cross section of the plating layer in a thickness direction, the area ratio of a lamellar structure in which an (Al—Zn) phase and a MgZn2 phase are arranged in layers is 10% to 90%, a lamellar spacing of the lamellar structure is 2.5 ?m or less, and the area ratio of an (Al—Zn) dendrite is 35% or less.
    Type: Application
    Filed: April 16, 2020
    Publication date: May 12, 2022
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Takuya MITSUNOBU, Jun MAKI, Hiroshi TAKEBAYASHI, Takehiro TAKAHASHI, Kohei TOKUDA
  • Patent number: 11326224
    Abstract: Provided are a stainless steel sheet with good corrosion resistance, low contact resistance and good press workability without the use of expensive materials such as gold or rare metals, and a method of manufacture the same. A method of manufacturing a stainless steel sheet includes: preparing a slab having a chemical composition including, in mass %: 20 to 26% Cr, up to 0.1% N, up to 2.0% Si, etc. (step S1); performing hot rolling and cold rolling on the slab to produce a rolled steel sheet with a thickness of 50 to 200 ?m (step S2); an annealing step in which the rolled steel sheet is annealed and cooled in a gas atmosphere containing nitrogen (step S3); and pickling the rolled steel sheet after the annealing step with a solution containing a non-oxidizing acid (step S4). The stainless steel sheet has an N content of 0.6 to 2.0% by mass.
    Type: Grant
    Filed: September 19, 2017
    Date of Patent: May 10, 2022
    Assignee: NIPPON STEEL STAINLESS STEEL CORPORATION
    Inventors: Hideya Kaminaka, Yoshitaka Nishiyama, Koichi Nose, Jun Maki, Junko Imamura, Kohei Maejima, Yuya Takashima
  • Publication number: 20220119921
    Abstract: A plated steel sheet having excellent chemical convertibility includes: a steel; and a plating layer that is provided on a surface of the steel, in which the plating layer includes, by mass %, Al: 5.00% to 35.00%, Mg: 2.50% to 13.00%, Fe: 5.00% to 35.00%, Si: 0% to 2.00%, Ca: 0.03% to 2.00%, and a remainder consisting of Zn and impurities, and in a surface of the plating layer, the area fraction of a Fe—Al phase is 0% to 30%, the area fraction of a rod-like lamellar structure of Zn and MgZn2 is 5% to 90%, the area fraction of a massive MgZn2 phase is 10% to 70%, and the area fraction of a remainder is 10% or less.
    Type: Application
    Filed: April 16, 2020
    Publication date: April 21, 2022
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Takuya MITSUNOBU, Jun MAKI, Hiroshi TAKEBAYASHI, Takehiro TAKAHASHI, Kohei TOKUDA
  • Publication number: 20220112589
    Abstract: A plated steel sheet having excellent post-coating corrosion resistance includes: a steel; and a plating layer that is provided on a surface of the steel, in which the plating layer includes, by mass %, Al: 5.00% to 35.00%, Mg: 2.50% to 13.00%, Fe: 5.00% to 35.00%, Si: 0% to 2.00%, Ca: 0% to 2.00%, and a remainder consisting of Zn and impurities, and in a cross section of the plating layer, the area fraction of a Fe2Al5 phase is 5.0% to 60.0%, the area fraction of an eutectic structure of Zn and MgZn2 is 10.0% to 80.0%, the area fraction of a massive MgZn2 phase is 5.0% to 40.0%, and the area fraction of a remainder is 10.0% or less.
    Type: Application
    Filed: April 16, 2020
    Publication date: April 14, 2022
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Takuya MITSUNOBU, Jun MAKI, Hiroshi TAKEBAYASHI, Takehiro TAKAHASHI, Kohei TOKUDA
  • Publication number: 20220010450
    Abstract: A Ni-coated steel sheet according to an aspect of the present invention includes: a base steel sheet; a diffusion alloy layer disposed on the base steel sheet; and a Ni-coated layer disposed on the diffusion alloy layer, in which a depth-hardness curve obtained by continuously performing Vickers hardness measurement on a cross section perpendicular to a rolled surface of the base steel sheet from a surface layer of the Ni-coated layer to the base steel sheet using a nanoindenter includes, in the diffusion alloy layer, a peak indicating a Vickers hardness of 1.50 times or more a Vickers hardness of the surface layer of the Ni-coated layer.
    Type: Application
    Filed: December 20, 2019
    Publication date: January 13, 2022
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Takehiro TAKAHASHI, Yasuto GOTO, Jun MAKI
  • Publication number: 20210197525
    Abstract: To solve the problem about the difference in temperature increasing rate between an overlapped part and a one-sheet part so as to further improve the corrosion resistance of plating after hot stamping.
    Type: Application
    Filed: April 5, 2019
    Publication date: July 1, 2021
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Soshi FUJITA, Yuki SUZUKI, Masahiro FUDA, Jun MAKI, Hideaki IRIKAWA, Masahiro NAKATA
  • Publication number: 20210164080
    Abstract: An aluminum-based plated steel sheet according to an aspect of the present invention includes: a base material; an aluminum-based plating layer located above the base material; and an intermetallic compound layer that is located between the base material and the aluminum-based plating layer and contains an intermetallic compound of Al and Fe, in which the base material has a chemical component within a predetermined range, the aluminum-based plating layer contains, on average, 80 mass % or more and 97 mass % or less of Al, 3 mass % or more and 15 mass % or less of Si, 0 mass % or more and 5 mass % or less of Zn, 0 mass % or more and 5 mass % or less of Fe, 0 mass % or more and 3 mass % or less in total of one or more selected from the group consisting of Mg and Ca, and impurities so that a total amount thereof is 100 mass %, an average value of a thickness of the intermetallic compound layer is 2 ?m or more and 10 ?m or less, a maximum value of the thickness of the intermetallic compound layer is 10 ?m or mor
    Type: Application
    Filed: December 5, 2018
    Publication date: June 3, 2021
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Soshi FUJITA, Yuki SUZUKI, Masahiro FUDA, Jun MAKI, Hideaki IRIKAWA, Takashi ARAMAKI, Tatsuya KUBOTA
  • Patent number: 10982303
    Abstract: There is provided a coated steel product having a steel product and a coating layer including a Zn—Al—Mg alloy layer disposed on a surface of the steel product, in which the Zn—Al—Mg alloy layer has a Zn phase, the Zn phase contains a Mg—Sn intermetallic compound phase, and the coating layer consists of Zn: more than 65.0%, Al: from more than 5.0% to less than 25.0%, Mg: from more than 3.0% to less than 12.5%, Sn: 0.1% to 20.0% in terms of percent (%) by mass, given amounts of optional elements, and impurities, and has a chemical composition that satisfies the following Formulas 1 to 5: Bi+In<Sn??Formula 1: Y+La+Ce?Ca??Formula 2: Si<Sn??Formula 3: 0?Cr+Ti+Ni+Co+V+Nb+Cu+Mn<0.25??Formula 4: 0?Sr+Sb+Pb+B<0.5.
    Type: Grant
    Filed: January 26, 2018
    Date of Patent: April 20, 2021
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Kohei Tokuda, Jun Maki, Yasuto Goto, Takuya Mitsunobu
  • Publication number: 20210095368
    Abstract: Fe-Al-based plated hot-stamped member exhibiting excellent formed part corrosion resistance and post-coating corrosion resistance and manufacturing method. The hot-stamping member includes Fe-Al-based plated layer on one or both surfaces of a base material, the base material has a predetermined steel component, Fe-Al-based plated layer has a thickness of 10 ?m or more and 60 ?m or less, formed by A, B, C and D layers sequentially from a surface toward the base material, and each of the four layers is a Fe-Al-based intermetallic compound containing Al, Fe, Si, Mn and Cr for predetermined contents with the balance made up of impurities, the D layer further contains Kirkendall voids each of which cross-sectional area is 3 ?m2-30 ?m2 for 10 pieces/6000 ?m2 or more and 40 pieces/6000 ?m2 or less.
    Type: Application
    Filed: February 15, 2019
    Publication date: April 1, 2021
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Soshi FUJITA, Yuki SUZUKI, Masahiro FUDA, Jun MAKI, Hideaki IRIKAWA, Tatsuya KUBOTA
  • Publication number: 20200347489
    Abstract: An Al plated electric resistance welded steel pipe for hardening use suppressing the formation of scale to the inside of the plating layer while performing hot forming and an Al plated hollow member using that Al plated electric resistance welded steel pipe, wherein the Al plated electric resistance welded steel pipe for hardening use is comprised of a base material made of a tubular steel plate and having a predetermined chemical composition and an electric resistance welded zone provided at a seam portion of the steel plate and extending in a longitudinal direction of the steel plate, the base material is further provided with an intermetallic compound layer positioned on the surface of the steel plate and including an Al-Fe-Si-based intermetallic compound and an Al plating layer positioned on the surface of the intermetallic compound layer and containing Al and Si, and 70×X/D?Y/t?30 is satisfied, wherein X (?m) is a thickness of the intermetallic compound layer, Y (?m) is a thickness of the Al plating laye
    Type: Application
    Filed: November 20, 2017
    Publication date: November 5, 2020
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Jun MAKI, Soshi FUJITA, Toyomitsu NAKAMURA