Patents by Inventor Yuji SAKIYAMA
Yuji SAKIYAMA 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: 11926120Abstract: This steel sheet for hot stamping includes a base material, an Al—Si alloy plating layer in which the Al content is 75 mass % or more, the Si content is 3 mass % or more and the total of the Al content and the Si content is 95 mass % or more and a Ni plating layer in which the Ni content is more than 90 mass % in this order, the chemical composition of the base material is, by mass %, C: 0.01% or more and less than 0.70%, Si: 0.005% to 1.000%, Mn: 0.40% to 3.00%, Nb: 0.010% to 0.200%, a solid solution of Nb: 0.010% to 0.150%, sol. Al: 0.00020% to 0.50000%, P: 0.100% or less, S: 0.1000% or less, N: 0.0100% or less, Cu: 0% to 1.00%, Ni: 0% to 1.00%, V: 0% to 1.00%, Ti: 0% to 0.150%, Mo: 0% to 1.000%, Cr: 0% to 1.000%, B: 0% to 0.0100%, Ca: 0% to 0.010%, REM: 0% to 0.300%, and a remainder: Fe and an impurity, the Al—Si alloy plating layer has a thickness of 7 to 148 ?m, and the Ni plating layer has a thickness of more than 200 nm and 2500 nm or less.Type: GrantFiled: May 13, 2021Date of Patent: March 12, 2024Assignee: NIPPON STEEL CORPORATIONInventors: Takayuki Harano, Yuji Sakiyama, Akinobu Kobayashi
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Patent number: 11904573Abstract: A hot-stamped article according to the present invention has a plating layer being attached to a single surface in an amount of 10 g/m2 or more and 90 g/m2 or less and having a Ni content of 10 mass % or more and 25 mass % or less with a remainder including Zn and impurities on a surface of a base steel sheet having a predetermined chemical composition, in a surface layer region, a metallographic structure includes 80.0% or more of martensite and 8.0% or more of residual austenite in terms of area percentage, and the concentration of Ni in the surface layer region is 8 mass % or more.Type: GrantFiled: May 28, 2020Date of Patent: February 20, 2024Assignee: NIPPON STEEL CORPORATIONInventors: Yuji Sakiyama, Yuri Toda, Kazuo Hikida
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Patent number: 11905581Abstract: A hot-stamped article according to the present invention has a plating layer being attached in an amount of 10 g/m2 or more and 90 g/m2 or less and having a Ni content of 10 mass % or more and 25 mass % or less with a remainder including Zn and an impurity on a surface of a base steel sheet having a predetermined chemical composition, a surface layer region includes 90.0% or more of martensite in terms of area percentage, and a concentration of Ni in a prior austenite grain boundary in the surface layer region is 5.5 mass % or more.Type: GrantFiled: May 28, 2020Date of Patent: February 20, 2024Assignee: NIPPON STEEL CORPORATIONInventors: Yuji Sakiyama, Yuri Toda, Tomohito Tanaka, Kazuo Hikida
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Publication number: 20230257844Abstract: Provided is a steel sheet comprising a sheet thickness center part and a first surface layer softened part and a second surface layer softened part respectively arranged at two sides of the sheet thickness center part, wherein the first surface layer softened part and second surface layer softened part have 10 ?m or more average thicknesses and have average Vickers hardnesses of 0.90 time or less of the average Vickers hardness of a sheet thickness ½ position, and the first surface layer softened part has an average Vickers hardness of 1.05 times or more the average Vickers hardness of the second surface layer softened part.Type: ApplicationFiled: August 6, 2021Publication date: August 17, 2023Applicant: NIPPON STEEL CORPORATIONInventors: Katsuya NAKANO, Yuji SAKIYAMA, Takashi YASUTOMI, Yoshiaki HONDA, Masahiro NAKATA
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Publication number: 20230250521Abstract: Provided is a steel sheet comprising a sheet thickness center part and a first surface layer part and a second surface layer part respectively arranged at two sides of the sheet thickness center part, wherein the first surface layer part and second surface layer part respectively independently have thicknesses of more than 10 ?m to 30% or less of the sheet thickness, the first surface layer part and second surface layer part have average Vickers hardnesses different from the average Vickers hardness of a sheet thickness ½ position, and a first hardness cumulative value at a region from a surface of the first surface layer part side to 30% of the sheet thickness is 1.05 times or more of a second hardness cumulative value at a region from a surface of the second surface layer part side to 30% of the sheet thickness.Type: ApplicationFiled: August 6, 2021Publication date: August 10, 2023Applicant: NIPPON STEEL CORPORATIONInventors: Yuji SAKIYAMA, Takashi YASUTOMI, Katsuya NAKANO, Yoshiaki HONDA, Masahiro NAKATA
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Publication number: 20230182190Abstract: This hot stamping member is a hot stamping member including a base material and a plating layer provided on the base material, in which the plating layer has a Ni-rich region, an Al-rich region and an Fe-rich region in this order from a surface of the plating layer, in a region from the surface of the plating layer to a 100 nm position in the thickness direction from the surface of the plating layer, Ni and Fe satisfy predetermined contents, in a region from the 100 nm position in the thickness direction from the surface of the plating layer to a 500 nm position in the thickness direction from the surface of the plating layer, Ni and Fe satisfy predetermined contents, and, in a region from the 500 nm position in the thickness direction from the surface of the plating layer to a 1000 nm position in the thickness direction from the surface of the plating layer, Ni and Fe satisfy predetermined contents.Type: ApplicationFiled: May 13, 2021Publication date: June 15, 2023Applicant: NIPPON STEEL CORPORATIONInventors: Akinobu KOBAYASHI, Yuji SAKIYAMA, Takayuki HARANO
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Publication number: 20230093517Abstract: This steel sheet for hot stamping includes a base material, an Al-Si alloy plating layer in which the Al content is 75 mass% or more, the Si content is 3 mass% or more and the total of the Al content and the Si content is 95 mass% or more and a Ni plating layer in which the Ni content is more than 90 mass% in this order, the chemical composition of the base material is, by mass%, C: 0.01% or more and less than 0.70%, Si: 0.005% to 1.000%, Mn: 0.40% to 3.00%, Nb: 0.010% to 0.200%, a solid solution of Nb: 0.010% to 0.150%, sol. A1: 0.00020% to 0.50000%, P: 0.100% or less, S: 0.1000% or less, N: 0.0100% or less, Cu: 0% to 1.00%, Ni: 0% to 1.00%, V: 0% to 1.00%, Ti: 0% to 0.150%, Mo: 0% to 1.000%, Cr: 0% to 1.000%, B: 0% to 0.0100%, Ca: 0% to 0.010%. REM: 0% to 0.300%, and a remainder: Fe and an impurity, the Al-Si alloy plating layer has a thickness of 7 to 148 µm, and the Ni plating layer has a thickness of more than 200 nm and 2500 nm or less.Type: ApplicationFiled: May 13, 2021Publication date: March 23, 2023Applicant: NIPPON STEEL CORPORATIONInventors: Takayuki HARANO, Yuji SAKIYAMA, Akinobu KOBAYASHI
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Publication number: 20230078655Abstract: This steel sheet for hot stamping includes a base material, an Al—Si alloy plating layer in which the Al content is 75 mass % or more, the Si content is 3 mass % or more and the total of the Al content and the Si content is 95 mass % or more, an Al oxide coating having a thickness of 0 to 20 nm and a Ni plating layer in which the Ni content is more than 90 mass % in this order, the base material has a predetermined chemical composition, the Al—Si alloy plating layer has a thickness of 7 to 148 ?m, and the Ni plating layer has a thickness of more than 200 nm and 2500 nm or less.Type: ApplicationFiled: May 13, 2021Publication date: March 16, 2023Applicant: NIPPON STEEL CORPORATIONInventors: Yuji SAKIYAMA, Akinobu KOBAYASHI, Takayuki HARANO
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Publication number: 20220234330Abstract: A hot-stamped article according to the present invention has a plating layer being attached to a single surface in an amount of 10 g/m2 or more and 90 g/m2 or less and having a Ni content of 10 mass % or more and 25 mass % or less with a remainder including Zn and impurities on a surface of a base steel sheet having a predetermined chemical composition, in a surface layer region, a metallographic structure includes 80.0% or more of martensite and 8.0% or more of residual austenite in terms of area percentage, and the concentration of Ni in the surface layer region is 8 mass % or more.Type: ApplicationFiled: May 28, 2020Publication date: July 28, 2022Applicant: NIPPON STEEL CORPORATIONInventors: Yuji SAKIYAMA, Yuri TODA, Kazuo HIKIDA
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Publication number: 20220227105Abstract: A steel sheet for hot stamping according to the present invention has a plating layer being attached in an amount of 10 g/m2 or more and 90 g/m2 or less and having a Ni content of 10 mass % or more and 25 mass % or less with a remainder including Zn and impurities on a surface of a base steel sheet having a predetermined chemical composition, in a surface layer region, 15.0% or more of the crystal grains of one or two kinds of unauto-tempered martensite and lower bainite are included in terms of area percentage, and the average dislocation density is 4×1015 m/m3.Type: ApplicationFiled: May 28, 2020Publication date: July 21, 2022Applicant: NIPPON STEEL CORPORATIONInventors: Yuji SAKIYAMA, Yuri TODA, Kazuo HIKIDA
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Publication number: 20220228244Abstract: A hot-stamped article according to the present invention has a plating layer being attached in an amount of 10 g/m2 or more and 90 g/m2 or less and having a Ni content of 10 mass % or more and 25 mass % or less with a remainder including Zn and an impurity on a surface of a base steel sheet having a predetermined chemical composition, a surface layer region includes 90.0 % or more of martensite in terms of area percentage, and a concentration of Ni in a prior austenite grain boundary in the surface layer region is 5.5 mass % or more.Type: ApplicationFiled: May 28, 2020Publication date: July 21, 2022Applicant: NIPPON STEEL CORPORATIONInventors: Yuji SAKIYAMA, Yuri TODA, Tomohito TANAKA, Kazuo HIKIDA