Patents Assigned to Nippon Steel Corporation
  • Publication number: 20220195554
    Abstract: A high strength steel sheet according to the present invention contains a predetermined chemical composition, in a metallographic structure, the total area ratio of tempered martensite and bainite is 80% or more, at a sheet thickness ¼ position of a cross section parallel to a rolling direction and perpendicular to a rolled surface, the standard deviation of number densities of precipitates having a diameter of 10 nm or less and including one or both of Ti and Nb is less than 5×1010 numbers/mm3, and the tensile strength is 780 MPa or more.
    Type: Application
    Filed: July 8, 2020
    Publication date: June 23, 2022
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Genki ABUKAWA, Hiroshi SHUTO
  • Publication number: 20220199320
    Abstract: Provided is a wound core formed by laminating a plurality of bent bodies obtained by forming a coated grain-oriented electrical steel sheet in which a coating is formed on at least one surface of a grain-oriented electrical steel sheet so that the coating is on an outside, in a sheet thickness direction, in which the bent body has a bent region obtained by bending the coated grain-oriented electrical steel sheet and a flat region adjacent to the bent region, the number of deformation twins present in the bent region in a side view is five or less per 1 mm of a length of a center line in the sheet thickness direction in the bent region, and when a region extending 40 times a sheet thickness to both sides in a circumferential direction from a center of the bent region on an outer circumferential surface of the bent body is defined as a strain affected region, a proportion of an area where the coating is not damaged at any position along the circumferential direction in a flat region within the strain affected r
    Type: Application
    Filed: April 27, 2020
    Publication date: June 23, 2022
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Takahito MIZUMURA, Masato MIZOKAMI, Hisashi MOGI, Fumiaki TAKAHASHI
  • Publication number: 20220195556
    Abstract: A steel sheet including a steel micro-structure containing, in volume fraction, tempered martensite: 85% or more, retained austenite: 5% or more to less than 15%, and ferrite, pearlite, bainite, and as-quenched martensite being less than 10% in total, when contents of Mn and C in the retained austenite are denoted by MnA and CA, and when contents of Mn and C in a matrix are denoted by MnM and CM, respectively, following Formulas (1) to (3) are satisfied, and the number of carbides having an equivalent circle radius of 0.1 ?m or more is 100 or less in a region measuring 20000 ?m2, and the steel sheet has a tensile strength of 1100 MPa or more. The steel sheet is excellent in crash resistance and formability. MnA/MnM?1.2??(1) CA/CM?5.0??(2) CA?1.
    Type: Application
    Filed: June 26, 2020
    Publication date: June 23, 2022
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Katsuya NAKANO, Kengo TAKEDA, Hiroyuki KAWATA, Akihiro UENISHI
  • Publication number: 20220195557
    Abstract: A hot-stamping formed body includes: a steel sheet having a predetermined chemical composition; and a plating layer provided on a surface of the steel sheet, the plating layer having an adhesion amount of 10 g/m2 to 90 g/m2 and a Ni content of 10 mass % to 25 mass %, and containing a remainder consisting of Zn and impurities. The hot-stamping formed body includes, in a surface layer region of the steel sheet, an average grain size of prior austenite grains to 10.0 ?m or less, a Ni concentration per unit area at grain boundaries having an average crystal orientation difference of 15° or more is 1.5 mass %/?m2 or more.
    Type: Application
    Filed: May 13, 2020
    Publication date: June 23, 2022
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Daisuke MAEDA, Yuri TODA, Tomohito TANAKA, Kazuo HIKIDA
  • Publication number: 20220193742
    Abstract: Provided is a blank made of a steel and comprising at least two protruding regions (313) having an outer edge (311) protruding outward in in-plane directions, in which a softened part (320) is formed at least partially in the protruding regions (313) and the softened part (320) is formed in at least a part of the outer edge of the protruding regions (313), a Vickers hardness of the softened part (320) is lower than a Vickers hardness of a main portion region (310), and the blank comprises at least two of the protruding regions (313) having the softened part (320).
    Type: Application
    Filed: April 9, 2020
    Publication date: June 23, 2022
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Soma SONOBE, Yasuhiro ITO
  • Publication number: 20220195567
    Abstract: A hot-stamping formed body includes: a steel sheet having a predetermined chemical composition; and a plating layer provided on a surface of the steel sheet, the plating layer having an adhesion amount of 10 g/m2 to 90 g/m2 and a Ni content of 10 mass % to 25 mass %, and containing a remainder consisting of Zn and impurities.
    Type: Application
    Filed: May 13, 2020
    Publication date: June 23, 2022
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Daisuke MAEDA, Yuri TODA, Kazuo HIKIDA
  • Publication number: 20220195548
    Abstract: A blank (100) includes a main portion (110) that is made of steel having a tensile strength of 1450 MPa or more and a softened portion (120), the ratio of Vickers hardness of the softened portion (120) to the Vickers hardness of the main portion (110) is 0.7 or more and 0.95 or less, and the softened portion (120) is disposed at a position different from a position of the main portion (110) in an in-plane direction. A structural member (200) includes a first member (210), a second member (220), and a weld (W) at which the first member (210) and the second member (220) are welded to each other.
    Type: Application
    Filed: April 10, 2020
    Publication date: June 23, 2022
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Yasuhiro ITO, Takashi YASUTOMI, Soma SONOBE
  • 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
  • Patent number: 11364524
    Abstract: A method for producing H-shaped steel, the method includes: a rough rolling step; an intermediate rolling step; and a finish rolling step, wherein: the rough rolling step includes: an edging rolling step of rolling and shaping a material to be rolled into a predetermined almost dog-bone shape; and a flat rolling step of performing rolling of a web part with the material to be rolled after completion of the edging rolling step rotated 90° or 270°; upper and lower caliber rolls of at least one caliber of calibers configured to perform the flat rolling step include recessed parts configured to form a raised part at a middle of a web part of the material to be rolled, the recessed parts being provided at roll barrel length middle parts of the upper and lower caliber rolls; and a side surface inclination angle ? of the formed raised part is set to 30° or more.
    Type: Grant
    Filed: December 19, 2016
    Date of Patent: June 21, 2022
    Assignee: NIPPON STEEL CORPORATION
    Inventor: Hiroshi Yamashita
  • 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
  • Patent number: 11365487
    Abstract: An electroplating apparatus is provided that minimizes unplated regions when an alloy plating layer is provided on the surface of a thread on a steel pipe. An electroplating apparatus (10) includes an electrode (1), sealing members (2, 3), and a plating-solution supply unit (4). The electrode (1) faces the thread (Tm). The sealing member (2) is positioned within the steel pipe (P1). The sealing member (3) is attached to the end portion of the steel pipe (P1) and, together with the sealing member (2), forms a receiving space (8). The plating-solution supply unit (4) includes a plurality of nozzles (42). The nozzles (42) are positioned within the receiving space (8) and adjacent one end of the thread (Tm) and arranged around the pipe axis of the steel pipe (P1). The plating-solution supply unit (4) injects a plating solution between the thread (Tm) and electrode (1) through the nozzles (42).
    Type: Grant
    Filed: June 18, 2020
    Date of Patent: June 21, 2022
    Assignees: Nippon Steel Corporation, Vallourec Oil and Gas France
    Inventors: Masanari Kimoto, Kazuya Ishii, Masahiro Oshima
  • Publication number: 20220186333
    Abstract: A high-strength steel sheet includes a predetermined chemical composition, a microstructure contains, by volume percentage, 95% or more of tempered martensite and bainite in total, and a remainder consists of ferrite and pearlite, the microstructure contains 5.0×109 pieces/mm or more of, per unit volume, precipitate having an equivalent circle diameter of 5.0 nm or less and containing Ti, Hvs/Hvc which is a ratio of an average hardness Hvs at a position of a depth of 20 ?m from a surface to an average hardness Hvc at a position of 0.20 to 0.50 mm from the surface is 0.85 or more, a tensile strength is 980 MPa or more, and a product of the tensile strength and elongation is 12,000 MPa×% or more.
    Type: Application
    Filed: March 19, 2020
    Publication date: June 16, 2022
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Masafumi AZUMA, Eisaku SAKURADA, Genki ABUKAWA, Kenichiro OTSUKA, Takeshi TOYODA
  • Publication number: 20220186337
    Abstract: This steel sheet has a predetermined chemical composition, in which the area ratio of plate martensite is 10% or more, the average grain size of prior austenite grains is 2.0 ?m to 10.0 ?m, the maximum diameter thereof is 20.0 ?m or less, the amount of solid solution C in martensite is 0.20 mass % or less, the average carbide size is 0.25 ?m or less, the crystal orientation difference between plate martensite and another martensite adjacent thereto in the same prior austenite grain is 10.0° or less, and the P concentration at grain boundaries of the prior austenite grains is 4.0 at % or less.
    Type: Application
    Filed: April 8, 2020
    Publication date: June 16, 2022
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Kohichi SANO, Hiroyuki KAWATA, Kengo TAKEDA
  • Publication number: 20220186351
    Abstract: A zinc-plated steel sheet for hot stamping includes a steel sheet having a predetermined chemical composition and a zinc plating film disposed on the steel sheet. In the zinc plating film, the plating adhesion amount is 15.0 g/m2 or more and less than 40.0 g/m2, the Fe concentration is 1.5 mass % or more and 8.0 mass % or less, the Al content is 100 mg/m2 or more and 400 mg/m2 or less, the Al concentration is 0.50 mass % or more and 3.00 mass % or less, and the remainder consists of Zn and impurities.
    Type: Application
    Filed: July 2, 2020
    Publication date: June 16, 2022
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Hiroyuki NAKAGAWA, Hiroki AKUTSU
  • Publication number: 20220186330
    Abstract: The present disclosure has as its object the provision of non-oriented electrical steel sheet excellent in magnetic properties which is free from any drop in magnetic flux density even after stress relief annealing and a method for manufacturing the same. Non-oriented electrical steel sheet having a chemical composition containing C: 0.0030 mass % or less, Si: 2.0 mass % or more and 4.0 mass % or less, Al: 0.010 mass % or more and 3.0 mass % or less, Mn: 0.10 mass % or more and 2.4% mass or less, P: 0.0050 mass % or more and 0.20 mass % or less, S: 0.0030 mass % or less, and one or more elements selected from the group comprising Mg, Ca, Sr, Ba, Ce, La, Nd, Pr, Zn, and Cd: total 0.00050 mass % or more and having a balance of Fe and unavoidable impurities, where, when designating a mass % of Si as [Si], a mass % of Al as [Al], and a mass % of Mn as [Mn], a parameter Q shown by the following formula (1) is 2.0 or more, a random intensity ratio of the {100} orientation is 2.
    Type: Application
    Filed: February 14, 2020
    Publication date: June 16, 2022
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Tesshu MURAKAWA, Hiroshi FUJIMURA, Takeaki WAKISAKA, Takeshi KUBOTA
  • Publication number: 20220184679
    Abstract: There is provided a zigzagging control method for a workpiece including: an estimation step of, before rolling of a tail portion of the workpiece, acquiring at least any one of an inter-roll thrust force estimated based on an inter-roll cross angle and an inter-roll friction coefficient and a material-roll thrust force estimated based on a material-roll cross angle and a material-roll friction coefficient; and a tail control step of, during the rolling of the tail portion of the workpiece, measuring work-side and drive-side rolling loads, correcting a rolling load difference or a rolling load difference ratio based on any two of acquired parameters including a roll-axis-direction thrust counterforce at the measurement of the rolling loads, the inter-roll thrust force, and the material-roll thrust force, and performing reduction leveling control on a rolling mill based on the corrected rolling load difference or rolling load difference ratio.
    Type: Application
    Filed: April 10, 2020
    Publication date: June 16, 2022
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Kazuma YAMAGUCHI, Atsushi ISHII, Daisuke NIKKUNI
  • Publication number: 20220186336
    Abstract: This electrical steel sheet contains, as a chemical composition, by mass %, C: 0.0035% or less, Si: 2.00% to 3.50%, Mn: 2.00% to 5.00%, P: 0.050% or less, S: 0.0070% or less, Al: 0.15% or less, N: 0.0030% or less, Ni: 0% to 1.00%, Cu: 0% to 0.10%, and a remainder: Fe and impurities, in which an X-ray random intensity ratio in a {100} <011> crystal orientation on a sheet surface is 15.0 to 50.0, and magnetic flux densities in 0°, 22.5°, and 45° directions from a rolling direction each satisfy [1.005×(B50 (0°)+B50 (45°))/2?B50 (22.5°)].
    Type: Application
    Filed: April 1, 2020
    Publication date: June 16, 2022
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Miho TOMITA, Yoshiaki NATORI, Hiroyoshi YASHIKI, Hiroshi FUJIMURA
  • Patent number: 11359298
    Abstract: A titanium foil or a titanium sheet is produced by electrodeposition from molten salt using constant current pulse, the method comprising: forming an electrodeposited titanium film on a surface of a cathode electrode made of glassy carbon, graphite, Mo, and Ni, and separating thereafter the electrodeposited titanium film from the cathode electrode by performing one or both of applying an external force to the electrodeposited titanium film and removing the cathode electrode. This enables the electrodeposited titanium film electrodeposited on the cathode electrode to be peeled from the cathode electrode simply and at low cost.
    Type: Grant
    Filed: March 1, 2018
    Date of Patent: June 14, 2022
    Assignees: KYOTO UNIVERSITY, NIPPON STEEL CORPORATION
    Inventors: Tetsuya Uda, Kouhei Funatsu, Akihiro Kishimoto, Kenichi Mori, Hideki Fujii
  • Patent number: 11358203
    Abstract: A method for producing a press-formed product includes a first pressing step and a second pressing step. In the first pressing step, an intermediate formed product is formed from a processed material by using first press tooling. The intermediate formed product includes a stepped section of a top plate section, a temporary vertical wall section adjacent to the top plate section via a ridge section and having at least part of the shape of the vertical wall section, and a temporary flange section adjacent to the temporary vertical wall section via a temporary ridge section. In the second pressing step, the press-formed product is formed from the intermediate formed product. In the second pressing step, forming is performed such that the temporary ridge section is moved toward the temporary flange section with at least part of the top plate section of the intermediate formed product restricted.
    Type: Grant
    Filed: April 3, 2017
    Date of Patent: June 14, 2022
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Junki Natori, Yoshiaki Nakazawa, Ryuichi Nishimura, Keiji Ogawa
  • Patent number: 11358213
    Abstract: The device for controlling a flow in a mold in thin-slab casting of steel has a thickness on the short side of the meniscus portion of 150 mm or less and a casting width of 2 m or less and includes a DC magnetic field generation unit and an immersion nozzle having a slit formed at the bottom so that the slit leads to the bottom of the discharge hole and opens outside, the discharge hole and the slit are present in the DC magnetic field zone, and the magnetic flux density B (T) in the DC magnetic field zone and the distance L (m) from the lower end of the immersion nozzle to the lower end of the core satisfy Formulae (1) and (2) described below: 0.35T?B?1.0T??Formula (1) L?0.
    Type: Grant
    Filed: June 7, 2019
    Date of Patent: June 14, 2022
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Hiroshi Harada, Keita Ikeda, Masashi Sakamoto, Yui Ito, Takuya Takayama