Patents by Inventor Yuri Toda
Yuri Toda 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: 20240011113Abstract: A steel sheet for hot stamping includes, as a chemical composition, by mass %: C: 0.060% to 0.120%; Si: 0% to 0.70%; Mn: 1.60% to 3.00%; P: 0.100% or less; S: 0.0100% or less; N: 0.0100% or less; Al: 0.001% to 0.100%; Ti: 0.005% to 0.050%; and B: 0.0005% to 0.0100%. If necessary, the chemical composition contains one or two or more selected from the group consisting of Nb, V, W, Ni, Cu, Mo, Sn, Ca, Mg, and REM and a remainder of Fe and impurities, A microstructure includes 70% or more of upper bainite by area ratio, and a number density of iron carbides having a major axis of 0.01 ?m or more included in the upper bainite is equal to or greater than 4/?m2.Type: ApplicationFiled: October 15, 2021Publication date: January 11, 2024Applicant: NIPPON STEEL CORPORATIONInventors: Masafumi AZUMA, Yuri TODA, Kenichiro OTSUKA
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Patent number: 11801897Abstract: In a frame member, the hardness of a sheet-thickness-direction central section in a portion where a softening layer is provided is greater than or equal to 400 Hv, the softening layer has hardness smaller by at least 10 Hv than the hardness of the sheet-thickness-direction central section in the portion where the softening layer is provided, the thickness of the softening layer is greater than or equal to 2% of the sheet thickness but smaller than 20% of the sheet thickness, the hardness of the softening layer at the surface is greater than or equal to 0.5 times the hardness of the sheet-thickness-direction central section but smaller than 0.Type: GrantFiled: October 9, 2019Date of Patent: October 31, 2023Assignee: NIPPON STEEL CORPORATIONInventors: Yuri Toda, Hiroaki Kubota, Hiroyuki Kawata, Daisuke Maeda
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Patent number: 11718347Abstract: The frame member has a flat sheet portion with a recessed portion having a pair of wall portions and a bottom portion extending between tip portions in an extending direction of the pair of wall portions, in which a Vickers hardness of a region of the flat sheet portion excluding the recessed portion is 330 Hv or more, a depth of the recessed portion is 5 mm or more, when a width of the recessed portion is L0 and a cross-sectional length of an inner peripheral wall of the recessed portion consisting of the pair of wall portions and the bottom portion is L1, a value of (L1?L0)/L0 is 0.18 or more and 2.8 or less, and a Vickers hardness of a ridgeline portion extending between the flat sheet portion and the recessed portion is 1.06 times or more and 1.20 times or less the Vickers hardness of the region of the flat sheet portion excluding the recessed portion.Type: GrantFiled: November 12, 2019Date of Patent: August 8, 2023Assignee: NIPPON STEEL CORPORATIONInventors: Hiroaki Kubota, Yuri Toda, Hiroyuki Kawata
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Patent number: 11702726Abstract: A hot stamped article having excellent shock absorption having a predetermined chemical composition, having a microstructure containing prior austenite having an average grain size of 3 ?m or less and further containing at least one of lower bainite, martensite, and tempered martensite in an area ratio of 90% or more, and having a grain boundary solid solution ratio Z defined by Z=(mass % of one or both of Nb and Mo at grain boundaries)/(mass % of one or both of Nb and Mo at time of melting) of 0.3 or more.Type: GrantFiled: March 29, 2018Date of Patent: July 18, 2023Assignee: NIPPON STEEL CORPORATIONInventors: Yuri Toda, Kazuo Hikida, Shingo Fujinaka, Tomohito Tanaka
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Patent number: 11639536Abstract: [Object] To provide a steel sheet for carburizing that demonstrates improved ductility, and a method for manufacturing the same. [Solution] A steel sheet consisting of, in mass %, C: more than or equal to 0.02%, and less than 0.30%, Si: more than or equal to 0.005%, and less than 0.5%, Mn: more than or equal to 0.01%, and less than 3.0%, P: less than or equal to 0.1%, S: less than or equal to 0.1%, sol. Al: more than or equal to 0.0002%, and less than or equal to 3.0%, N: less than or equal to 0.2%, Ti: more than or equal to 0.010%, and less than or equal to 0.150%, and the balance: Fe and impurities, in which the number of carbides per 1000 ?m2 is 100 or less, percentage of number of carbides with an aspect ratio of 2.0 or smaller is 10% or larger relative to the total carbides, average equivalent circle diameter of carbide is 5.0 ?m or smaller, and average crystal grain size of ferrite is 10 ?m or smaller.Type: GrantFiled: August 30, 2018Date of Patent: May 2, 2023Assignee: NIPPON STEEL CORPORATIONInventors: Motonori Hashimoto, Kazuo Hikida, Yuri Toda
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Publication number: 20230091784Abstract: This hot-stamping formed body has a predetermined chemical composition and has a metallographic structure consisting of, by area ratio, a total of 10% to 30% of ferrite and granular bainite and a remainder in microstructure consisting of one or more of martensite, bainite, and tempered martensite, and, in textures of a surface layer region and an inside region, ratios between a pole density of an orientation group consisting of {001}<1-10> to {001}<?1-10> and a pole density of an orientation group consisting of {111}<1-10> to {111}<?1-12> are controlled.Type: ApplicationFiled: May 7, 2021Publication date: March 23, 2023Applicant: NIPPON STEEL CORPORATIONInventors: Yuri TODA, Daisuke MAEDA, Shingo FUJINAKA
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Publication number: 20230081832Abstract: These steel sheet for hot stamping and hot-stamping formed body have predetermined chemical composition and metallographic structures, and, in textures of a surface layer region and an inside region, ratios between a pole density of an orientation group consisting of {001}<1-10> to {001}<?1-10> and a pole density of an orientation group consisting of {111}<1-10> to {111}<?1-12> are controlled.Type: ApplicationFiled: May 7, 2021Publication date: March 16, 2023Applicant: NIPPON STEEL CORPORATIONInventors: Daisuke MAEDA, Yuri TODA, Shingo FUJINAKA
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Publication number: 20230040050Abstract: A hot-stamping formed body has a predetermined chemical composition and includes microstructure which includes residual austenite of which an area ratio is in a range of 20% to 30%. Among grain boundaries of crystal grains of bainite and tempered martensite in the microstructure, a ratio of a length of a grain boundary having a rotation angle in a range of 55° to 75° to a total length of a grain boundary having a rotation angle in a range of 4° to 12°, a grain boundary having a rotation angle in a range of 49° to 54°, and a grain boundary having a rotation angle in a range of 55° to 75° to the <011> direction as a rotation axis is 30% or more.Type: ApplicationFiled: January 8, 2021Publication date: February 9, 2023Applicant: NIPPON STEEL CORPORATIONInventors: Yuri TODA, Kodai MURASAWA, Daisuke MAEDA, Kazuo HIKIDA
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Patent number: 11572610Abstract: A steel sheet includes a predetermined chemical composition and a metal structure represented by, in area fraction, ferrite: 50% to 95%, granular bainite: 5% to 48%, martensite: 2% to 30%, and upper bainite, lower bainite, tempered martensite, retained austenite, and pearlite: 5% or less in total.Type: GrantFiled: January 25, 2017Date of Patent: February 7, 2023Assignee: NIPPON STEEL CORPORATIONInventors: Katsuya Nakano, Kunio Hayashi, Yuri Toda, Eisaku Sakurada, Akihiro Uenishi
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Publication number: 20230002874Abstract: A hot-stamping formed body has a predetermined chemical composition and includes microstructure which includes residual austenite of which an area ratio is 5% or more and less than 10%. Among grain boundaries of crystal grains of bainite and tempered martensite in the microstructure, a ratio of a length of a grain boundary having a rotation angle in a range of 55° to 75° to a total length of a grain boundary having a rotation angle in a range of 4° to 12°, a grain boundary having a rotation angle in a range of 49° to 54°, and a grain boundary having a rotation angle in a range of 55° to 75° to the <011> direction as a rotation axis is 30% or more. The tensile strength of the hot-stamping formed body is 1500 MPa or more.Type: ApplicationFiled: January 8, 2021Publication date: January 5, 2023Applicant: NIPPON STEEL CORPORATIONInventors: Yuri TODA, Shinichiro TABATA, Kodai MURASAWA, Daisuke MAEDA, Kazuo HIKIDA
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Publication number: 20230001466Abstract: A hot-stamping formed body has a predetermined chemical composition and includes microstructure which includes residual austenite of which an area ratio is 10% or more and less than 20%, Among grain boundaries of crystal grains of bainite and tempered martensite a ratio of a length of a grain boundary having a rotation angle in a range of 55° to 75° to a total length of a grain boundary having a rotation angle in a range of 4° to 12°, a grain boundary having a rotation angle in a range of 49° to 54°, and the grain boundary having a rotation angle in, a range of 55° to 75° to the <011> direction as a rotation axis is 30% or more.Type: ApplicationFiled: January 8, 2021Publication date: January 5, 2023Applicant: NIPPON STEEL CORPORATIONInventors: Yuri TODA, Kodai MURASAWA, Daisuke MAEDA, Kazuo HIKIDA
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Publication number: 20220403492Abstract: A hot stamped body with high strength, good bendability and crack propagation resistance, consisting of: in mass %, C: 0.06% or more to less than 0.20%, Si: 0.010-1.00%, Mn: 0.80-2.00%, P: 0.100% or less, S: 0.010% or less, Al: 0.010-0.500%, N: 0.010% or less, Nb: more than 0.020% to 0.10% or less, Ti: 0-0.10%, V: 0-0.10%, Cr: 0-0.50%, Mo: 0-1.00%, B: 0-0.0100%, Ni: 0-0.50%, REM: 0-0.0100%, Mg: 0-0.010%, Ca: 0-0.0100%, and Co: 0-2.0%, with the balance: Fe and impurities, wherein a microstructure includes, in area fraction, ferrite: 5-50%, and martensite: 50-95%, a proportion of regions in the martensite where GAIQ values are 35000 or more to less than 45000 is 30 area % or more, and a maximum bending angle ? (deg) is 90 or more.Type: ApplicationFiled: January 15, 2021Publication date: December 22, 2022Applicant: NIPPON STEEL CORPORATIONInventors: Daisuke MAEDA, Shingo FUJINAKA, Yuri TODA
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Publication number: 20220403490Abstract: A hot stamped body with high strength and good bendability, comprising a chemical composition consisting of: in mass %, C: 0.06% or more to less than 0.20%, Si: 0.010 to 1.00%, Mn: 1.20 to 3.00%, P: 0.100% or less, S: 0.010% or less, Al: 0.010 to 0.500%, N: 0.010% or less, Nb: 0.0010 to 0.020%, Ti: 0 to 0.10%, V: 0 to 0.10%, Cr: 0 to 0.50%, Mo: 0 to 1.00%, B: 0 to 0.0100%, Ni: 0 to 0.50%, REM: 0 to 0.0100%, Mg: 0 to 0.010%, Ca: 0 to 0.0100%, and Co: 0 to 2.0%, with the balance: Fe and impurities, wherein a microstructure includes martensite: 85% or more, a proportion of regions in the martensite where GAIQ values are 35000 or more to less than 45000 is 30 area % or more, and TS×?, is 105000 or more, and ? is 75 or more.Type: ApplicationFiled: January 15, 2021Publication date: December 22, 2022Applicant: NIPPON STEEL CORPORATIONInventors: Shingo FUJINAKA, Daisuke MAEDA, Yuri TODA
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Patent number: 11512373Abstract: A hot-stamping formed body has a predetermined chemical composition and a microstructure including, by area ratio, 90% to 100% of martensite and 0% to 10% of a remainder in the microstructure. In the microstructure, a region in which an average GAIQ value in a unit grain is 60,000 or more is 30 area % or more, and a number density of carbides having a circle equivalent diameter of 0.20 ?m or more is 50/mm2 or less.Type: GrantFiled: March 19, 2020Date of Patent: November 29, 2022Assignee: NIPPON STEEL CORPORATIONInventors: Shingo Fujinaka, Yuri Toda, Daisuke Maeda
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Patent number: 11492687Abstract: A steel sheet has a predetermined chemical composition and a metal structure represented by, in area fraction, polygonal ferrite: 40% or less, martensite: 20% or less, bainitic ferrite: 50% to 95%, and retained austenite: 5% to 50%. In area fraction, 80% or more of the bainitic ferrite is composed of bainitic ferrite grains that have an aspect ratio of 0.1 to 1.0 and have a dislocation density of 8×102 (cm/cm3) or less in a region surrounded by a grain boundary with a misorientation angle of 15° or more. In area fraction, 80% or more of the retained austenite is composed of retained austenite grains that have an aspect ratio of 0.1 to 1.0, have a major axis length of 1.0 ?m to 28.0 ?m, and have a minor axis length of 0.1 ?m to 2.8 ?m.Type: GrantFiled: March 30, 2018Date of Patent: November 8, 2022Assignee: NIPPON STEEL CORPORATIONInventors: Yuri Toda, Eisaku Sakurada, Kunio Hayashi, Akihiro Uenishi
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Patent number: 11453935Abstract: A steel sheet for hot stamping use used as a material for a hot stamped article excellent in strength or bending deformability, having a predetermined chemical composition, having a microstructure containing at least one of lower bainite, martensite, and tempered martensite in an area ratio of 90% or more, having an X-ray random intensity ratio of {112}<111> of the crystal grains forming the above lower bainite, martensite, or tempered martensite of 2.8 or more, having a number density of grain size 50 nm or less cementite or epsilon carbides in the microstructure of 1×1016/cm3 or more, and having a grain boundary solid solution ratio Z defined by Z=(mass % of one or both of Nb and Mo at grain boundaries)/(mass % of one or both of Nb and Mo at time of melting) of 0.4 or more.Type: GrantFiled: March 29, 2018Date of Patent: September 27, 2022Assignee: NIPPON STEEL CORPORATIONInventors: Yuri Toda, Kazuo Hikida, Shingo Fujinaka, Tomohito Tanaka
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Patent number: 11427900Abstract: A steel sheet includes a predetermined chemical composition and a metal structure represented by, in area fraction, ferrite: 50% to 95%, granular bainite: 5% to 48%, tempered martensite: 2% to 30%, upper bainite, lower bainite, fresh martensite, retained austenite, and pearlite: 5% or less in total, and the product of the area fraction of the tempered martensite and a Vickers hardness of the tempered martensite: 800 to 10500.Type: GrantFiled: January 31, 2017Date of Patent: August 30, 2022Assignee: NIPPON STEEL CORPORATIONInventors: Katsuya Nakano, Kunio Hayashi, Yuri Toda, Eisaku Sakurada, Akihiro Uenishi
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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