Patents by Inventor Kohei Tokuda
Kohei Tokuda 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).
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Patent number: 12043900Abstract: A plated steel material having a plating layer having an average chemical composition containing, in mass %, Zn: more than 50.00%, Al: more than 15.0% and less than 30.0%, Mg: more than 5.0% and less than 15.0%, and Si: 0.25% or more and less than 3.50%, and impurities, and wherein a total amount (?A) of at least one selected from the group consisting of Sn, Bi and In is less than 1.00%, a total amount (?B) of at least one selected from the group consisting of Ca, Y, La, Ce and Sr is 0.02% or more and less than 0.60%, 2.0?SMg/Si<20.0 (Formula 1), 3.0?Si/?B<24.0 (Formula 2), and 26.0?(Si/?B)×(Mg/Si)<375.0 (Formula 3) are satisfied, and in an X-ray diffraction pattern of the surface of the plating layer, a diffraction intensity ratio R1 defined by R1={I(16.18°)+I(32.69°)}/I(27.0°) (Formula 4) satisfies 2.5<R1 (Formula 5) is used.Type: GrantFiled: November 30, 2021Date of Patent: July 23, 2024Assignee: NIPPON STEEL CORPORATIONInventors: Kohei Tokuda, Mamoru Saito, Takuya Mitsunobu, Tetsuya Toba, Yasuto Goto, Atsushi Morishita, Yasuaki Kawamura, Fumiaki Nakamura, Koji Kawanishi
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Patent number: 11965249Abstract: A surface-treated metal material includes a metal sheet, a plating layer formed on the metal sheet and containing aluminum, magnesium, and zinc, and a composite coating formed on a surface of the plating layer, the composite coating including an organic silicon compound, one or two of a zirconium compound and a titanium compound, a phosphoric acid compound, a fluorine compound, and a vanadium compound, wherein, when a surface of the composite coating is analyzed at a spot size of ?30 ?m using micro-fluorescent X-rays, a maximum value of V/Zn, which is a mass ratio of a V content to a Zn content, is 0.010 to 0.100.Type: GrantFiled: March 19, 2020Date of Patent: April 23, 2024Assignee: NIPPON STEEL CORPORATIONInventors: Hiromasa Shoji, Kiyokazu Ishizuka, Kohei Tokuda, Mamoru Saito, Yasuto Goto, Ikumi Tokuda
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Patent number: 11965250Abstract: A hot stamped steel includes a base material, a plated layer that is formed on a surface of the base material, and an oxide film that is formed on a surface of the plated layer; chemical composition of the plated layer contains 20.00 to 45.00 mass % of Al, 10.00 to 45.00 mass % of Fe, 4.50 to 15.00 mass % of Mg, 0.10 to 3.00 mass % of Si, 0.05 to 3.00 mass % of Ca, 0 to 0.50 mass % of Sb, 0 to 0.50 mass % of Pb, 0 to 1.00 mass % of Cu, 0 to 1.00 mass % of Sn, 0 to 1.00 mass % of Ti, 0 to 0.50 mass % of Sr, 0 to 1.00 mass % of Cr, 0 to 1.00 mass % of Ni, and 0 to 1.00 mass % of Mn with a remainder of Zn and impurities; and chemical composition of the oxide film contains 20.0 to 55.0 at % of Mg, 0.5 to 15.0 at % of Ca, 0 to 15.0 at % of Zn, and 0 at % or more and less than 10.0 at % of Al with a remainder of O and a total of 5.0 at % or less of impurities, and the adhesion amount of the oxide film per one surface is in a range of 0.01 to 10 g/m2.Type: GrantFiled: August 28, 2020Date of Patent: April 23, 2024Assignee: NIPPON STEEL CORPORATIONInventors: Takuya Mitsunobu, Kohei Tokuda, Takehiro Takahashi, Hiroshi Takebayashi
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Publication number: 20240093340Abstract: The hot-dip plated steel material includes a steel material and a hot-dip plated layer disposed on a surface of the steel material, the hot-dip plated layer has a certain chemical composition, and the hot-dip plated layer has a diffraction intensity obtained from a result of X-ray diffraction measurement, the diffraction intensity satisfying a certain relationship.Type: ApplicationFiled: March 31, 2023Publication date: March 21, 2024Applicant: NIPPON STEEL CORPORATIONInventors: Takuya MITSUNOBU, Kohei TOKUDA, Hiroshi TAKEBAYASHI
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Publication number: 20240084422Abstract: The hot-dip plated steel material includes a steel material and a hot-dip plated layer disposed on a surface of the steel material, the hot-dip plated layer has a certain chemical composition, and the hot-dip plated layer has a diffraction intensity obtained from a result of X-ray diffraction measurement, the diffraction intensity satisfying a certain relationship.Type: ApplicationFiled: March 23, 2023Publication date: March 14, 2024Applicant: NIPPON STEEL CORPORATIONInventors: Takuya MITSUNOBU, Kohei TOKUDA, Hiroshi TAKEBAYASHI
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Publication number: 20240043980Abstract: A plated steel material having a plating layer having an average chemical composition containing, in mass %, Zn: more than 50.00%, Al: more than 15.0% and less than 30.0%, Mg: more than 5.0% and less than 15.0%, and Si: 0.25% or more and less than 3.50%, and impurities, and wherein a total amount (?A) of at least one selected from the group consisting of Sn, Bi and In is less than 1.00%, a total amount (?B) of at least one selected from the group consisting of Ca, Y, La, Ce and Sr is 0.02% or more and less than 0.60%, 2.0?SMg/Si<20.0 (Formula 1), 3.0?Si/?B<24.0 (Formula 2), and 26.0?(Si/?B)×(Mg/Si)<375.0 (Formula 3) are satisfied, and in an X-ray diffraction pattern of the surface of the plating layer, a diffraction intensity ratio R1 defined by R1={I(16.18°)+I(32.69°)}/I(27.0°) (Formula 4) satisfies 2.5<R1 (Formula 5) is used.Type: ApplicationFiled: November 30, 2021Publication date: February 8, 2024Applicant: NIPPON STEEL CORPORATIONInventors: Kohei TOKUDA, Mamoru SAITO, Takuya MITSUNOBU, Tetsuya TOBA, Yasuto GOTO, Atsushi MORISHITA, Yasuaki KAWAMURA, Fumiaki NAKAMURA, Koji KAWANISHI
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Patent number: 11851764Abstract: The plated steel material is a plated steel material including a steel material and a plating layer provided on the surface of the steel material, wherein the plating layer has a predetermined average chemical composition, when the amount of Mg is % Mg and the amount of Al is % Al, % Mg/% Al is 0.80 or more, and a metal structure in a total field of view of 25,000 ?m2 in a vertical cross section which is a cross section in a thickness direction of the plating layer includes 10 to 40 area % of a MgZn2 phase, 10 to 30 area % of an Al—Zn phase with a Zn content of 10% or more, 0 to 15 area % of an Al phase with a Zn content of less than 10%, and 25 area % or more of an Al/MgZn2/Zn ternary eutectic structure.Type: GrantFiled: November 18, 2021Date of Patent: December 26, 2023Assignee: NIPPON STEEL CORPORATIONInventors: Kotaro Ishii, Kohei Tokuda, Yoshinari Ishida, Yasuto Goto, Mamoru Saito
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Patent number: 11814732Abstract: A hot-dip plated steel includes a base steel and a hot-dip plating layer on a surface of the base steel, a chemical composition of the hot-dip plating layer contains, by mass %, Al: 10.00% to 30.00%, Mg: 3.00% to 12.00%, Sn: 0% to 2.00%, Si: 0% to 2.50%, Ca: 0% to 3.00%, Ni: 0% or more and less than 0.25%, Fe: 0% to 5.00%, and the like, a remainder includes Zn and impurities, a metallographic structure of the hot-dip plating layer contains 5 to 45 area % of an ? phase having a grain diameter of 0.5 to 2 ?m, the metallographic structure of the hot-dip plating layer contains 15 to 70 area % of a MgZn2 phase, and, among the ? phases having the grain diameter of 0.5 to 2 ?m, an area ratio of an ? phase having a (111)?//(0001)MgZn2 orientation relationship to the adjacent MgZn2 phase is 25% to 100%.Type: GrantFiled: September 7, 2021Date of Patent: November 14, 2023Assignee: Nippon Steel CorporationInventors: Takuya Mitsunobu, Mamoru Saito, Kohei Tokuda, Hiroshi Takebayashi
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Patent number: 11781200Abstract: A plated steel including a plated layer on a surface of a steel, in which Expression 1 of 0?Cr+Ti+Ni+Co+V+Nb+Cu+Mn?0.25 and Expression 2 of 0?Sr+Sb+Pb+B+Li+Zr+Mo+W+Ag+P?0.50 are satisfied, and Expression 3 of I(MgZn2 (41.31°))/I?(MgZn2)?0.265 and Expression 6 of 0.150?{I(MgZn2 (20.79°))+I(MgZn2 (42.24°))}/I?(MgZn2) are further satisfied in an X-ray diffraction pattern of a surface of the plated layer measured using Cu-K? rays under a condition that an X-ray output is 40 kV and 150 mA.Type: GrantFiled: July 9, 2021Date of Patent: October 10, 2023Assignee: NIPPON STEEL CORPORATIONInventors: Kohei Tokuda, Takuya Mitsunobu, Mamoru Saito, Yuto Fukuda, Yasuto Goto, Hidetoshi Shindo, Fumiaki Nakamura, Koji Kawanishi, Ryohei Mimura
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Publication number: 20230304136Abstract: The plated steel material is a plated steel material including a steel material and a plating layer provided on the surface of the steel material, wherein the plating layer has a predetermined average chemical composition, when the amount of Mg is % Mg and the amount of Al is % Al, % Mg/% Al is 0.80 or more, and a metal structure in a total field of view of 25,000 ?m2 in a vertical cross section which is a cross section in a thickness direction of the plating layer includes 10 to 40 area % of a MgZn2 phase, 10 to 30 area % of an Al—Zn phase with a Zn content of 10% or more, 0 to 15 area % of an Al phase with a Zn content of less than 10%, and 25 area % or more of an Al/MgZn2/Zn ternary eutectic structure.Type: ApplicationFiled: November 18, 2021Publication date: September 28, 2023Applicant: NIPPON STEEL CORPORATIONInventors: Kotaro ISHII, Kohei TOKUDA, Yoshinari ISHIDA, Yasuto GOTO, Mamoru SAITO
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Patent number: 11725259Abstract: 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: GrantFiled: April 16, 2020Date of Patent: August 15, 2023Assignee: NIPPON STEEL CORPORATIONInventors: Takuya Mitsunobu, Jun Maki, Hiroshi Takebayashi, Takehiro Takahashi, Kohei Tokuda
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Patent number: 11697266Abstract: 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: GrantFiled: April 16, 2020Date of Patent: July 11, 2023Assignee: NIPPON STEEL CORPORATIONInventors: Takuya Mitsunobu, Jun Maki, Hiroshi Takebayashi, Takehiro Takahashi, Kohei Tokuda
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Publication number: 20230203635Abstract: A hot-dip plated steel according to one aspect includes a base steel and a hot-dip plating layer disposed on a surface of the base steel, a chemical composition of the hot-dip plating layer contains, by mass%, Al: 10.00% to 30.00%, Mg: 3.00% to 12.00%, Sn: 0% to 2.00%, Si: 0% to 2.50%, Ca: 0% to 3.00%, Ni: 0% or more and less than 0.25%, Fe: 0% to 5.00%, and the like, a remainder consists of Zn and impurities, a metallographic structure of the hot-dip plating layer contains 5 to 45 area% of an ? phase having a grain diameter of 0.5 to 2 µm, the metallographic structure of the hot-dip plating layer contains 15 to 70 area% of a MgZn2 phase, and, among the ? phases having the grain diameter of 0.5 to 2 µm, an area ratio of an ? phase having a (111)?//(0001)MgZn2 orientation relationship to the adjacent MgZn2 phase is 25% to 100%.Type: ApplicationFiled: September 7, 2021Publication date: June 29, 2023Inventors: Takuya MITSUNOBU, Mamoru SAITO, Kohei TOKUDA, Hiroshi TAKEBAYASHI
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Publication number: 20230193425Abstract: A plated steel including a plated layer on a surface of a steel, in which Expression 1 of 0?Cr+Ti+Ni+Co+V+Nb+Cu+Mn 0.25 and Expression 2 of 0?Sr+Sb+Pb+B+Li+Zr+Mo+W+Ag+P?0.50 are satisfied, and Expression 3 of I(MgZn2 (41.31°))/I?(MgZn2)?0.265 and Expression 6 of 0.150?{I(MgZn2 (20.79°))+I(MgZn2 (42.24°))}/I?(MgZn2) are further satisfied in an X-ray diffraction pattern of a surface of the plated layer measured using Cu-K? rays under a condition that an X-ray output is 40 kV and 150 mA.Type: ApplicationFiled: July 9, 2021Publication date: June 22, 2023Applicant: NIPPON STEEL CORPORATIONInventors: Kohei TOKUDA, Takuya MITSUNOBU, Mamoru SAITO, Yuto FUKUDA, Yasuto GOTO, Hidetoshi SHINDO, Fumiaki NAKAMURA, Koji KAWANISHI, Ryohei MIMURA
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Patent number: 11634790Abstract: 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: GrantFiled: April 16, 2020Date of Patent: April 25, 2023Assignee: NIPPON STEEL CORPORATIONInventors: Takuya Mitsunobu, Jun Maki, Hiroshi Takebayashi, Takehiro Takahashi, Kohei Tokuda
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Patent number: 11634791Abstract: 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: GrantFiled: April 16, 2020Date of Patent: April 25, 2023Assignee: NIPPON STEEL CORPORATIONInventors: Kohei Tokuda, Mamoru Saito, Jun Maki, Takuya Mitsunobu, Yasuto Goto
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Patent number: 11584981Abstract: 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: GrantFiled: April 16, 2020Date of Patent: February 21, 2023Assignee: NIPPON STEEL CORPORATIONInventors: Takuya Mitsunobu, Jun Maki, Hiroshi Takebayashi, Takehiro Takahashi, Kohei Tokuda
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Patent number: 11555235Abstract: Provided is a metallic coated steel product which is less likely to experience LME and blowhole formation and is likely to exhibit an improved corrosion resistance at welding heat affected zones. The metallic coated steel product is a hot-dip metallic coated steel product including a steel product and a plating layer that is provided on a surface of the steel product and includes a Zn—Al—Mg alloy layer. In a cross-section of the Zn—Al—Mg alloy layer an area fraction of MgZn2 phase is from 45 to 75%, a total area fraction of MgZn2 and Al phases is not less than 70%, and an area fraction of Zn—Al—MgZn2 ternary eutectic structure is from 0 to 5%; and the plating layer has a predetermined chemical composition.Type: GrantFiled: January 26, 2018Date of Patent: January 17, 2023Assignee: NIPPON STEEL CORPORATIONInventors: Kohei Tokuda, Yoshinari Ishida, Takuya Mitsunobu, Nobuyuki Shimoda
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Publication number: 20220356547Abstract: 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: ApplicationFiled: April 16, 2020Publication date: November 10, 2022Inventors: Kohei TOKUDA, Mamoru SAITO, Jun MAKI, Takuya MITSUNOBU, Yasuto GOTO
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Patent number: 11473174Abstract: The present invention provides a coated steel product including: a steel product; a coating layer that is coated on the surface of the steel product and that includes from 8 to 50% by mass of Mg, from 2.5 to 70.0% by mass of Al, and from 0.30 to 5.00% by mass of Ca, with the balance consisting of Zn and impurities; and an intermediate layer interposed between the steel product and the coating layer, in which the intermediate layer has a sea-island structure constituted by a sea portion composed of an Al—Fe alloy phase, and island portions including a Zn—Mg—Al alloy phase having a Mg content of 8% by mass or more, and in which the sea portion composed of the Al—Fe alloy phase has an area fraction of from 55 to 90%.Type: GrantFiled: January 16, 2017Date of Patent: October 18, 2022Assignee: NIPPON STEEL CORPORATIONInventors: Kohei Tokuda, Hisashi Baba, Nobuyuki Shimoda, Kenichiro Matsumura, Yasuto Goto