Patents by Inventor Soshi Fujita
Soshi Fujita 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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Publication number: 20240091842Abstract: A plated steel sheet for hot stamping according to one aspect of the present invention includes a steel sheet, a plating layer formed on either surface or both surfaces of the steel sheet and having an Al content of 60 mass % or more, and a surface film layer formed on the plating layer. A thickness t of the plating layer is 10 to 60 ?m. An average crystal grain diameter of the plating layer in a thickness range from an interface between the plating layer and the surface film layer to a position at ? of the thickness t is 2t/3 or less and 15.0 ?m or less. A surface film layer contains particles containing one or more elements selected from A group elements consisting of Sc, V, Mn, Fe, Co, Ce, Nb, Mo, and W. A total content of the A group elements is 0.01 to 10.0 g/m2. An average grain diameter of the particles containing the A group elements is 0.05 to 3.0 ?m.Type: ApplicationFiled: November 29, 2019Publication date: March 21, 2024Applicant: NIPPON STEEL CORPORATIONInventors: Yuki SUZUKI, Soshi FUJITA, Jun MAKI, Kazuhisa KUSUMI, Masahiro FUDA
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Publication number: 20240068080Abstract: A hot-stamped product with improved delayed-fracture resistance is provided. The hot-stamped product 1 includes: a steel substrate 10; and an Al film 20 formed on the steel substrate 10, the Al film 20 including: an interface layer 21 located at the interface with the steel substrate 10 and with part of the ?Fe substituted by Al and Si; an intermediate layer 22 formed on the interface layer 21; and an oxide layer formed on the intermediate layer, the intermediate layer 22 including an Fe—Al—Si phase 22a with part of the ?Fe substituted by Al and Si, the Fe—Al—Si phase 22a including one or more elements selected from the group consisting of Zr, Ce, Y, Ta, Ni, Cu, Nb, Cr, Co, V and Ti, the oxide layer 23 including one or more elements selected from the group consisting of Be, Mg, Ca, Sr, Ba, Sc and Zn.Type: ApplicationFiled: March 14, 2022Publication date: February 29, 2024Inventors: Takashi DOI, Kenji KOBAYASHI, Naomi INATOMI, Yuki SUZUKI, Soshi FUJITA, Masahiro FUDA
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Patent number: 11905600Abstract: Provided is an Al-plated hot stamped steel material comprising a steel base material, an Al-plating layer formed on at least one surface of the steel base material, and a chemical conversion coating formed on the Al-plating layer and containing zinc phosphate-based crystals and Ce-based compounds deposited on the surfaces of the zinc phosphate-based crystals, wherein an amount of deposition of the zinc phosphate-based crystals in the chemical conversion coating is, converted to metal Zn, 0.3 to 4.0 g/m2 and an area ratio of the Ce-based compounds in the chemical conversion coating is 0.5 to 25%.Type: GrantFiled: March 24, 2021Date of Patent: February 20, 2024Assignee: NIPPON STEEL CORPORATIONInventors: Shinichi Yamaguchi, Soshi Fujita
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Publication number: 20240044012Abstract: To provide a steel sheet for hot stamping suitable for manufacturing, through hot-stamping working, a component having portions with different strengths, and a hot-stamped member having portions with different strengths. A steel sheet for hot stamping according to the present invention includes, on a surface of the steel sheet: a site having a surface-treated film whose emissivity at a wavelength of 8.0 ?m at 25° C. is 60% or more; and a site at which the surface-treated film is not provided, in which the surface-treated film contains carbon black, and one or more of oxides selected from a group consisting of a Zr oxide, a Zn oxide, and a Ti oxide, in which the carbon black and the oxides exist while being dispersed over the entire surface-treated film, the surface-treated film has a silica content of 0 to 0.3 g/m2, and when an adhesion amount of the carbon black and an adhesion amount of the oxides are set to XCB (g/m2) and XOxide (g/m2), respectively, an equation (1) below is satisfied.Type: ApplicationFiled: April 8, 2021Publication date: February 8, 2024Applicant: NIPPON STEEL CORPORATIONInventors: Yuki SUZUKI, Kenta UENISHI, Soshi FUJITA, Masahiro FUDA
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Publication number: 20230416888Abstract: 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 layeType: ApplicationFiled: September 7, 2023Publication date: December 28, 2023Applicant: NIPPON STEEL CORPORATIONInventors: Jun MAKI, Soshi FUJITA, Toyomitsu NAKAMURA
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Patent number: 11807924Abstract: 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 layeType: GrantFiled: November 20, 2017Date of Patent: November 7, 2023Assignee: NIPPON STEEL CORPORATIONInventors: Jun Maki, Soshi Fujita, Toyomitsu Nakamura
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Publication number: 20230166314Abstract: This manufacturing method of a hot press-formed article includes a heating step of heating an Al-plated steel sheet and a forming step of obtaining a hot press-formed article using a die after the heating step, the Al-plated steel sheet has a base steel sheet, an Al plating layer, and a coating layer, the coating layer is a metal layer containing at least one metal of Mg, Ca, V, Ti, and Zn, a metal oxide layer containing an oxide of one or more of Mg, Ca, V, Ti, and Zn, or a mixed layer including the metal layer and the metal oxide layer, the die has a hard layer on a surface, HVDie that is a surface hardness of the die at a position of the hard layer is HV1500 or more and HV3800 or less, and a temperature Tm of the Al-plated steel sheet at a start of forming and an average movement velocity V of the die in the forming step satisfy 800?(HVDie/40)?Tm?850?(V/4)?(HVDie/100).Type: ApplicationFiled: April 20, 2021Publication date: June 1, 2023Applicant: NIPPON STEEL CORPORATIONInventors: Soshi FUJITA, Yuki SUZUKI, Masahiro FUDA, Hideaki IRIKAWA, Masahiro KUBO, Naruhiko NOMURA
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Publication number: 20230138051Abstract: Provided is an Al-plated hot stamped steel material comprising a steel base material, an Al-plating layer formed on at least one surface of the steel base material, and a chemical conversion coating formed on the Al-plating layer and containing zinc phosphate-based crystals and Ce-based compounds deposited on the surfaces of the zinc phosphate-based crystals, wherein an amount of deposition of the zinc phosphate-based crystals in the chemical conversion coating is, converted to metal Zn, 0.3 to 4.0 g/m2 and an area ratio of the Ce-based compounds in the chemical conversion coating is 0.5 to 25%.Type: ApplicationFiled: March 24, 2021Publication date: May 4, 2023Applicant: NIPPON STEEL CORPORATIONInventors: Shinichi YAMAGUCHI, Soshi FUJITA
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Publication number: 20230116894Abstract: Provided is a hot stamped body comprising a steel base material, an Al-plating layer formed on at least one surface of the steel base material, a coating formed on the Al-plating layer and containing ZnO particles and CeO2 particles having an average particle size smaller than an average particle size of the ZnO particles, and a Zn- and Al-containing complex oxide layer formed between the Al-plating layer and the coating. Further, provided is a method for producing a hot stamped body comprising forming an Al-plating layer on at least one side of a steel sheet, coating a surface of the Al-plating layer with an aqueous solution containing ZnO particles and CeO2 particles, then heating it to form a coating containing ZnO particles and CeO2 particles on the Al-plating layer, and hot pressing the steel sheet.Type: ApplicationFiled: May 18, 2020Publication date: April 13, 2023Applicant: NIPPON STEEL CORPORATIONInventors: Michiko KONNO, Jun MAKI, Shinichi YAMAGUCHI, Soshi FUJITA
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Patent number: 11535916Abstract: 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 morType: GrantFiled: December 5, 2018Date of Patent: December 27, 2022Assignee: NIPPON STEEL CORPORATIONInventors: Soshi Fujita, Yuki Suzuki, Masahiro Fuda, Jun Maki, Hideaki Irikawa, Takashi Aramaki, Tatsuya Kubota
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Publication number: 20220402015Abstract: 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: ApplicationFiled: February 24, 2021Publication date: December 22, 2022Applicant: NIPPON STEEL CORPORATIONInventors: Soshi FUJITA, Yuki SUZUKI, Masahiro FUDA, Hideaki IRIKAWA, Jun MAKI, Nobuo YOSHIKAWA, Naruhiko NOMURA
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Patent number: 11530474Abstract: 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: GrantFiled: February 15, 2019Date of Patent: December 20, 2022Assignee: NIPPON STEEL CORPORATIONInventors: Soshi Fujita, Yuki Suzuki, Masahiro Fuda, Jun Maki, Hideaki Irikawa, Tatsuya Kubota
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Patent number: 11364707Abstract: 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: GrantFiled: April 5, 2019Date of Patent: June 21, 2022Assignee: NIPPON STEEL CORPORATIONInventors: Soshi Fujita, Yuki Suzuki, Masahiro Fuda, Jun Maki, Hideaki Irikawa, Masahiro Nakata
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Publication number: 20220025498Abstract: This aluminum-plated steel sheet has a steel sheet and a plating layer formed on a surface of the steel sheet, the plating layer contains one or more A group elements selected from a group consisting of Be, Mg, Ca, Sr, Ba, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn, a remainder of Al, Fe, and impurities, a thickness t of the plating layer is 10 to 60 ?m, and an average grain size is 2t/3 or less and 15 ?m or less in a thickness range from an outermost surface of the plating layer to a ? thickness t position.Type: ApplicationFiled: November 29, 2019Publication date: January 27, 2022Applicant: NIPPON STEEL CORPORATIONInventors: Yuki SUZUKI, Soshi FUJITA, Masahiro FUDA, Hideaki IRIKAWA, Takeshi IMAI, Fumio EIHARA
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Publication number: 20210222804Abstract: This steel sheet includes a first coated portion in which an intermetallic compound layer and an aluminum coating layer are provided on a surface of a base steel sheet in order from the base steel sheet side, a first exposed portion in which the base steel sheet is exposed, and a second coated portion in which the intermetallic compound layer and the aluminum coating layer are provided on the surface of the base steel sheet in order from the base steel sheet side, in which in a first direction which is perpendicular to a thickness direction of the steel sheet and is directed from the first coated portion to one end edge of the steel sheet, the first coated portion, the first exposed portion, the second coated portion, and the end edge of the steel sheet are disposed in this order on one surface of the base steel sheet, at least the first coated portion, the first exposed portion, and the end edge of the steel sheet are disposed in this order on the other surface of the base steel sheet in the first direction,Type: ApplicationFiled: May 15, 2019Publication date: July 22, 2021Applicant: NIPPON STEEL CORPORATIONInventors: Hiroki FUJIMOTO, Masanori YASUYAMA, Yujiro TATSUMI, Hiroshi FUKUCHI, Shintaro KOBAYASHI, Soshi FUJITA, Tasuku ZENIYA, Yuki SUZUKI, Yoshinari ISHIDA
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Publication number: 20210197525Abstract: 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: ApplicationFiled: April 5, 2019Publication date: July 1, 2021Applicant: NIPPON STEEL CORPORATIONInventors: Soshi FUJITA, Yuki SUZUKI, Masahiro FUDA, Jun MAKI, Hideaki IRIKAWA, Masahiro NAKATA
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Publication number: 20210164080Abstract: 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 morType: ApplicationFiled: December 5, 2018Publication date: June 3, 2021Applicant: NIPPON STEEL CORPORATIONInventors: Soshi FUJITA, Yuki SUZUKI, Masahiro FUDA, Jun MAKI, Hideaki IRIKAWA, Takashi ARAMAKI, Tatsuya KUBOTA
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Publication number: 20210114074Abstract: A method of producing a hot press-formed product includes subjecting an Al-plated steel sheet having a zinc compound layer or a metallic zinc layer, as an outermost layer, provided on an Al plating layer to hot press forming using a die. The die includes a hard layer having a skewness (Rsk), as measured in a direction from the outside of a die hole toward the inside of the die hole, of 1.3 or less and a hardness Hv_Die of HV 2,000 or more, over the entirety of a region of a steel sheet contact surface that is adjacent to a die shoulder portion. The steel sheet contact surface is a surface located outside of the die hole and configured to contact the Al-plated steel sheet that is to be subjected to the hot press forming.Type: ApplicationFiled: April 9, 2019Publication date: April 22, 2021Applicant: NIPPON STEEL CORPORATIONInventors: Masahiro KUBO, Soshi FUJITA, Yoshiaki NAKAZAWA, Hideaki IRIKAWA, Masahiro FUDA
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Publication number: 20210095368Abstract: 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: ApplicationFiled: February 15, 2019Publication date: April 1, 2021Applicant: NIPPON STEEL CORPORATIONInventors: Soshi FUJITA, Yuki SUZUKI, Masahiro FUDA, Jun MAKI, Hideaki IRIKAWA, Tatsuya KUBOTA
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Publication number: 20200347489Abstract: 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 layeType: ApplicationFiled: November 20, 2017Publication date: November 5, 2020Applicant: NIPPON STEEL CORPORATIONInventors: Jun MAKI, Soshi FUJITA, Toyomitsu NAKAMURA