Patents by Inventor Kazuhisa Kusumi

Kazuhisa Kusumi 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: 11371130
    Abstract: A hot-dip Sn—Zn-based alloy-plated steel sheet according to an aspect of the present invention includes: a steel sheet having a predetermined chemical composition; a diffusion alloy layer provided on one surface or both surfaces of the steel sheet; and a Sn—Zn-plated layer provided on the diffusion alloy layer, in which the diffusion alloy layer contains Fe, Sn, Zn, Cr, and Ni, an area ratio of a Sn—Fe—Cr—Zn phase to a Sn—Fe—Ni—Zn phase in the diffusion alloy layer is 0.01 or more and less than 2.5, the diffusion alloy layer has a coverage of 98% or more with respect to the one surface, the Sn—Zn-plated layer contains 1% to 20% of Zn by mass % and a remainder consisting of Sn and impurities, and an adhesion amount of the Sn—Zn-plated layer is 10 to 80 g/m2 per one surface.
    Type: Grant
    Filed: April 26, 2019
    Date of Patent: June 28, 2022
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Masahiro Fuda, Toshinori Mizuguchi, Junji Nakano, Yoshiharu Inoue, Kazuhisa Kusumi, Yasuaki Naito
  • Patent number: 11352684
    Abstract: The present invention has as its object the provision of a steel member and steel sheet having high tensile strength and toughness and excellent in hydrogen embrittlement resistance in a corrosive environment and methods for manufacturing the same. The steel member of the present invention has predetermined chemical constituents and has a maximum value of content of Cu in a range from the surface to a depth of 0 to 30 ?m of 1.4 times the content of Cu at a depth of 200 ?m.
    Type: Grant
    Filed: February 5, 2020
    Date of Patent: June 7, 2022
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Shinichiro Tabata, Kazuhisa Kusumi, Kazuo Hikida, Hideaki Irikawa
  • Publication number: 20210395870
    Abstract: The present invention has as its object the provision of a steel member and steel sheet having high tensile strength and toughness and excellent in hydrogen embrittlement resistance in a corrosive environment and methods for manufacturing the same. The steel member of the present invention has predetermined chemical constituents and has a maximum value of content of Cu in a range from the surface to a depth of 0 to 30 ?m of 1.4 times the content of Cu at a depth of 200 ?m.
    Type: Application
    Filed: February 5, 2020
    Publication date: December 23, 2021
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Shinichiro TABATA, Kazuhisa KUSUMI, Kazuo HIKIDA, Hideaki IRIKAWA
  • Publication number: 20210262073
    Abstract: A steel member according to an aspect of the present invention has a predetermined chemical composition, in which a metallographic structure includes, by a volume %, 60.0% to 85.0% of martensite, 10.0% to 30.0% of bainite, 5.0% to 15.0% of residual austenite, and 0% to 4.0% of a remainder in microstructure. A length of a maximum minor axis of the residual austenite is 30 nm or longer. A number density of a carbide which exist in the steel member and has a circle equivalent diameter of 0.1 ?m or more and an aspect ratio of 2.5 or less is 4.0×103 pieces/mm2 or less.
    Type: Application
    Filed: April 23, 2019
    Publication date: August 26, 2021
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Shinichiro TABATA, Yoshihiro SUWA, Kazuo HIKIDA, Kazuhisa KUSUMI
  • Publication number: 20210156017
    Abstract: A hot-dip Sn—Zn-based alloy-plated steel sheet according to an aspect of the present invention includes: a steel sheet having a predetermined chemical composition; a diffusion alloy layer provided on one surface or both surfaces of the steel sheet; and a Sn—Zn-plated layer provided on the diffusion alloy layer, in which the diffusion alloy layer contains Fe, Sn, Zn, Cr, and Ni, an area ratio of a Sn—Fe—Cr—Zn phase to a Sn—Fe—Ni—Zn phase in the diffusion alloy layer is 0.01 or more and less than 2.5, the diffusion alloy layer has a coverage of 98% or more with respect to the one surface, the Sn—Zn-plated layer contains 1% to 20% of Zn by mass % and a remainder consisting of Sn and impurities, and an adhesion amount of the Sn—Zn-plated layer is 10 to 80 g/m2 per one surface.
    Type: Application
    Filed: April 26, 2019
    Publication date: May 27, 2021
    Applicant: Nippon Steel Corporation
    Inventors: Masahiro FUDA, Toshinori MIZUGUCHI, Junji NAKANO, Yoshiharu INOUE, Kazuhisa KUSUMI, Yasuaki NAITO
  • Publication number: 20200189233
    Abstract: A hot stamped member has a steel, an Al—Fe intermetallic compound layer formed on the steel, and an oxide film layer formed on the Al—Fe intermetallic compound layer, in which the oxide film layer is made up of one or more A group elements selected from the group consisting of Be, Mg, Ca, Sr, Ba, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn, Al, oxygen, and impurities, a proportion of the A group element in the oxide film layer excluding the oxygen is 0.01 atom % or more and 80 atom % or less, a thickness t of the oxide film layer is 0.1 to 10.0 ?m, and, in the case of measuring the A group element in the oxide film layer in a thickness direction from a surface of the oxide film layer using a GDS, a maximum value of a detection intensity of the A group element in a range from the surface to one-third of the thickness t is 3.0 times or more an average value of detection intensities of the A group element in a range from two thirds of the thickness t to t.
    Type: Application
    Filed: June 1, 2018
    Publication date: June 18, 2020
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Yuki SUZUKI, Soshi FUJITA, Jun MAKI, Kazuhisa KUSUMI, Masahiro FUDA, Hideaki IRIKAWA
  • Publication number: 20190366686
    Abstract: The present invention provides an alloyed Al plated steel sheet for hot stamping, which is a steel sheet having, on the surface, an Al—Fe alloyed layer that includes an A phase (Fe—Al-based alloy phase including 45% to 85% of Fe and 4% to 13% of Si) and has a thickness of 15 ?m or more, in which a proportion of a length occupied by the A phase in an uppermost surface of a cross section perpendicular to the surface of the steel sheet is 10% or more and 50% or less.
    Type: Application
    Filed: February 2, 2017
    Publication date: December 5, 2019
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Masahiro FUDA, Jun MAKI, Soshi FUJITA, Kazuhisa KUSUMI, Shinichiro TABATA
  • Publication number: 20190271063
    Abstract: The present invention has as its object the provision of steel sheet for hot stamping use which is excellent in part strength after hot stamping and delayed fracture resistance comprised of large C content high strength steel sheet in which effective hydrogen traps are formed in the steel material. The steel sheet of the present invention solves this problem by forming Fe—Mn-based composite oxides in the steel sheet and trapping hydrogen at the interfaces of the composite oxides and matrix steel and in the voids around the composite oxides. Specifically, it provides steel sheet for hot stamping use which is comprised of chemical ingredients which contain, by mass %, C: 0.05 to 0.40%, Si: 0.02% or less, Mn: 0.1 to 3%, S: 0.02% or less, P: 0.03% or less, Al: 0.005% or less, Ti: 0.01% or less, N: 0.01% or less, one or both of Cr and Mo in a total of 0.005 to 1%, and O: 0.003 to 0.03% and which have a balance of Fe and unavoidable impurities and which contains average diameter 0.
    Type: Application
    Filed: May 17, 2019
    Publication date: September 5, 2019
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Kazuhisa KUSUMI, Yuji OGAWA, Masayuki ABE, Hidekuni MURAKAMI, Kengo TAKEDA, Jun MAKI
  • Patent number: 10344360
    Abstract: The present invention has as its object the provision of steel sheet for hot stamping use which is excellent in part strength after hot stamping and delayed fracture resistance comprised of large C content high strength steel sheet in which effective hydrogen traps are formed in the steel material. The steel sheet of the present invention solves this problem by forming Fe—Mn-based composite oxides in the steel sheet and trapping hydrogen at the interfaces of the composite oxides and matrix steel and in the voids around the composite oxides. Specifically, it provides steel sheet for hot stamping use which is comprised of chemical ingredients which contain, by mass %, C: 0.05 to 0.40%, Si: 0.02% or less, Mn: 0.1 to 3%, S: 0.02% or less, P: 0.03% or less, Al: 0.005% or less, Ti: 0.01% or less, N: 0.01% or less, one or both of Cr and Mo in a total of 0.005 to 1%, and O: 0.003 to 0.03% and which have a balance of Fe and unavoidable impurities and which contains average diameter 0.
    Type: Grant
    Filed: March 9, 2011
    Date of Patent: July 9, 2019
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Kazuhisa Kusumi, Yuji Ogawa, Masayuki Abe, Hidekuni Murakami, Kengo Takeda, Jun Maki
  • Patent number: 10113220
    Abstract: A high strength hot dipped galvanized steel sheet is provided. By controlling the amount of addition of Ti instead of the addition of Nb or B, it is possible to obtain an effect of retarding recrystallization and grain growth even if annealing by a continuous annealing process in a temperature range of the general annealing temperature of 720° C. to a temperature of the lower of 800° C. or Ac3 temperature. By controlling the rolling and heat treatment conditions, it is possible to control the ferrite phase rate, grain size of the low temperature transformed phases, ratio of average values of the nano hardnesses of the ferrite phase and low temperature transformed phases, and fluctuations of hardnesses of the low temperature transformed phases in a composite structure steel of ferrite and low temperature transformed phases and obtain a high strength hot dipped galvanized steel sheet.
    Type: Grant
    Filed: September 17, 2015
    Date of Patent: October 30, 2018
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Kengo Takeda, Kazuhisa Kusumi, Haruhiko Eguchi, Jun Hirowatari, Shintarou Fujii
  • Patent number: 10092938
    Abstract: The present invention provides plated steel sheet for hot press use which is excellent in hot lubricity, coating adhesion, spot weldability, and coated corrosion resistance and a method of hot pressing plated steel sheet. The present invention is Plated steel sheet for hot press use and a method of hot pressing plated steel sheet characterized by being plated steel sheet for hot press use which contains an Al plating layer which is formed on one surface or both surfaces of said steel sheet, and a surface coating layer which is formed on said Al plating layer, said surface coating layer containing at least one Zn compound which is selected from a group comprised of Zn hydroxide, Zn phosphate, and a Zn organic acid.
    Type: Grant
    Filed: February 8, 2013
    Date of Patent: October 9, 2018
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Shintaro Yamanaka, Jun Maki, Masao Kurosaki, Kazuhisa Kusumi
  • Patent number: 9821858
    Abstract: An Al-plated steel sheet includes: a steel sheet; an Al plating layer which is formed on one surface or both surfaces of the steel sheet and contains at least 85% or more of Al by mass %; and a surface coating layer which is laminated on the surface of the Al plating layer and contains ZnO and one or more lubricity improving compounds.
    Type: Grant
    Filed: April 15, 2013
    Date of Patent: November 21, 2017
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Jun Maki, Masao Kurosaki, Kazuhisa Kusumi, Shintaro Yamanaka
  • Patent number: 9644252
    Abstract: A hot stamped high strength part in which the propagation of cracks which form at the plating layer at the time of hot stamping when hot stamping aluminum plated steel sheet is suppressed and the post painting anticorrosion property is excellent even without adding special ingredient elements which suppress formation of cracks in an aluminum plating layer is provided.
    Type: Grant
    Filed: January 29, 2015
    Date of Patent: May 9, 2017
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Jun Maki, Kazuhisa Kusumi, Masayuki Abe, Masao Kurosaki
  • Publication number: 20160002756
    Abstract: A high strength hot dipped galvanized steel sheet is provided. By controlling the amount of addition of Ti instead of the addition of Nb or B, it is possible to obtain an effect of retarding recrystallization and grain growth even if annealing by a continuous annealing process in a temperature range of the general annealing temperature of 720° C. to a temperature of the lower of 800° C. or Ac3 temperature. By controlling the rolling and heat treatment conditions, it is possible to control the ferrite phase rate, grain size of the low temperature transformed phases, ratio of average values of the nano hardnesses of the ferrite phase and low temperature transformed phases, and fluctuations of hardnesses of the low temperature transformed phases in a composite structure steel of ferrite and low temperature transformed phases and obtain a high strength hot dipped galvanized steel sheet.
    Type: Application
    Filed: September 17, 2015
    Publication date: January 7, 2016
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Kengo TAKEDA, Kazuhisa KUSUMI, Haruhiko EGUCHI, Jun HIROWATARI, Shintarou FUJII
  • Patent number: 9228244
    Abstract: A high strength hot dipped galvanized steel sheet is provided. By controlling the amount of addition of Ti instead of the addition of Nb or B, it is possible to obtain an effect of retarding recrystallization and grain growth even if annealing by a continuous annealing process in a temperature range of the general annealing temperature of 720° C. to a temperature of the lower of 800° C. or Ac3 temperature. By controlling the rolling and heat treatment conditions, it is possible to control the ferrite phase rate, grain size of the low temperature transformed phases, ratio of average values of the nano hardnesses of the ferrite phase and low temperature transformed phases, and fluctuations of hardnesses of the low temperature transformed phases in a composite structure steel of ferrite and low temperature transformed phases and obtain a high strength hot dipped galvanized steel sheet.
    Type: Grant
    Filed: March 31, 2011
    Date of Patent: January 5, 2016
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Kengo Takeda, Kazuhisa Kusumi, Haruhiko Eguchi, Jun Hirowatari, Shintarou Fujii
  • Publication number: 20150191813
    Abstract: A hot stamped high strength part in which the propagation of cracks which form at the plating layer at the time of hot stamping when hot stamping aluminum plated steel sheet is suppressed and the post painting anticorrosion property is excellent even without adding special ingredient elements which suppress formation of cracks in an aluminum plating layer is provided.
    Type: Application
    Filed: January 29, 2015
    Publication date: July 9, 2015
    Inventors: Jun Maki, Kazuhisa Kusumi, Masayuki Abe, Masao Kurosaki
  • Patent number: 8992704
    Abstract: The present invention solves the problem of melting of Al in heating before hot-stamping, which had been a problem in the past in applying hot-stamping to Al-plated steel sheet, and provides Al-plated steel sheet for hot-stamping and a method of hot-stamping using that Al-plated steel sheet to solve the problem of delayed fracture due to residual hydrogen, and, furthermore, a method of a rapid heating hot-stamping using that Al-plated steel sheet. The Al-plated steel sheet of the present invention is produced by annealing the Al-plated steel sheet as coiled in a box-anneal furnace for the time and at the temperature indicated in FIG. 5, and alloying of a plated Al and a steel sheet. Further, a method of rapid heating hot-stamping in the present invention is characterized by cutting out a stamping blank of an Al-plated steel sheet, and heating that blank in heating before hot-stamping by an average temperature with a rising rate of 40° C./sec or more and a time of exposure to an environment of 700° C.
    Type: Grant
    Filed: July 13, 2009
    Date of Patent: March 31, 2015
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Jun Maki, Masayuki Abe, Kazuhisa Kusumi, Yasushi Tsukano
  • Patent number: 8986849
    Abstract: A hot stamped high strength part which is excellent in post painting anticorrosion property, which hot stamped high strength part has an alloy plating layer including an Al—Fe intermetallic compound phase on the surface of the steel sheet. The alloy plating layer is comprised from phases of a plurality of intermetallic compounds, a mean linear intercept length of crystal grains of a phase containing Al: 40 to 65 mass % among the phases of the plurality of intermetallic compounds is 3 to 20 ?m, an average value of thickness of the Al—Fe alloy plating layer is 10 to 50 ?m, and a ratio of the average value of thickness to the standard deviation of thickness of the Al—Fe alloy plating layer satisfies the following relationship: 0<standard deviation of thickness/average value of thickness?0.15.
    Type: Grant
    Filed: March 30, 2012
    Date of Patent: March 24, 2015
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Jun Maki, Kazuhisa Kusumi, Masayuki Abe, Masao Kurosaki
  • Publication number: 20150044499
    Abstract: An Al-plated steel sheet includes: a steel sheet; an Al plating layer which is formed on one surface or both surfaces of the steel sheet and contains at least 85% or more of Al by mass %; and a surface coating layer which is laminated on the surface of the Al plating layer and contains ZnO and one or more lubricity improving compounds.
    Type: Application
    Filed: April 15, 2013
    Publication date: February 12, 2015
    Inventors: Jun Maki, Masao Kurosaki, Kazuhisa Kusumi, Shintaro Yamanaka
  • Publication number: 20150020562
    Abstract: The present invention provides plated steel sheet for hot press use which is excellent in hot lubricity, coating adhesion, spot weldability, and coated corrosion resistance and a method of hot pressing plated steel sheet. The present invention is Plated steel sheet for hot press use and a method of hot pressing plated steel sheet characterized by being plated steel sheet for hot press use which contains an Al plating layer which is formed on one surface or both surfaces of said steel sheet, and a surface coating layer which is formed on said Al plating layer, said surface coating layer containing at least one Zn compound which is selected from a group comprised of Zn hydroxide, Zn phosphate, and a Zn organic acid.
    Type: Application
    Filed: February 8, 2013
    Publication date: January 22, 2015
    Inventors: Shintaro Yamanaka, Jun Maki, Masao Kurosaki, Kazuhisa Kusumi