Patents by Inventor Masaharu Oka
Masaharu Oka 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: 12221669Abstract: A hot-rolled steel sheet which has excellent rigidity along with high strength, excellent workability, and excellent LME resistance is provided. A hot-rolled steel sheet of the present embodiment consists of, in mass %, C: 0.040 to 0.120%, Si: 0.01 to 0.60%, Mn: 0.50 to 1.50%, P: 0.025% or less, S: 0.010% or less, Al: 0.010 to 0.070%, N: 0.0070% or less, Ti: 0.055 to 0.200%, and B: 0.0010 to 0.0050%, with the balance being Fe and impurities. In the microstructure of the hot-rolled steel sheet, an area fraction of bainitic ferrite is 85% or more and the dislocation density is 8.0×1013 to 100.0×1013/m2. The average equivalent circular diameter of Ti carbides in the hot-rolled steel sheet is 10 nm or less, and the average equivalent circular diameter of grains of the bainitic ferrite is 15 ?m or less.Type: GrantFiled: September 22, 2022Date of Patent: February 11, 2025Assignee: NIPPON STEEL CORPORATIONInventors: Kentarou Hirata, Masaharu Oka, Masahito Sakaki, Mamoru Saito
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Publication number: 20240425945Abstract: A hot-rolled steel sheet which has excellent rigidity along with high strength, excellent workability, and excellent LME resistance is provided. A hot-rolled steel sheet of the present embodiment consists of, in mass %, C: 0.040 to 0.120%, Si: 0.01 to 0.60%, Mn: 0.50 to 1.50%, P: 0.025% or less, S: 0.010% or less, Al: 0.010 to 0.070%, N: 0.0070% or less, Ti: 0.055 to 0.200%, and B: 0.0010 to 0.0050%, with the balance being Fe and impurities. In the microstructure of the hot-rolled steel sheet, an area fraction of bainitic ferrite is 85% or more and the dislocation density is 8.0×1013 to 100.0×1013/m2. The average equivalent circular diameter of Ti carbides in the hot-rolled steel sheet is 10 nm or less, and the average equivalent circular diameter of grains of the bainitic ferrite is 15 ?m or less.Type: ApplicationFiled: September 22, 2022Publication date: December 26, 2024Applicant: NIPPON STEEL CORPORATIONInventors: Kentarou HIRATA, Masaharu OKA, Masahito SAKAKI, Mamoru SAITO
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Publication number: 20240183013Abstract: A surface-treated steel sheet is provided that has excellent strength even when the surface-treated steel sheet is provided with a Ni—Co—Fe alloy layer. A surface-treated steel sheet of the present disclosure includes a steel sheet, and a Ni—Co—Fe alloy layer on a steel sheet surface. The steel sheet has a microstructure containing: ferrite, and one or more kinds selected from the group consisting of cementite, pearlite, and bainite having an area fraction of 1.2 to 5.0% in total. The Ni—Co—Fe alloy layer contains Ni, Co and Fe.Type: ApplicationFiled: March 31, 2022Publication date: June 6, 2024Applicant: NIPPON STEEL CORPORATIONInventors: Kosuke KAWAMOTO, Yasuto GOTO, Masaharu OKA, Yuta DAIROKUNO, Yuji KAJII, Koki SHIMADA
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Publication number: 20230034898Abstract: A hot-rolled steel sheet has a predetermined chemical composition in which a microstructure includes 99% or more of martensite by volume fraction and a remainder in microstructure including residual austenite and ferrite, in a cross section parallel to a rolling direction, an average aspect ratio of prior austenite grains is less than 3.0, a proportion of sulfides having an aspect ratio of more than 3.0 among sulfides having an area of 1.0 ?m2 or more is 1.0% or, less, in a thickness middle portion, and a pole density of {211} <011> orientation is 3.0 or less, and a tensile strength TS is 980 MPa or higher.Type: ApplicationFiled: January 29, 2021Publication date: February 2, 2023Applicant: NIPPON STEEL CORPORATIONInventors: Masaharu OKA, Nobusato KOJIMA, Mitsuru YOSHIDA
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Patent number: 10907236Abstract: A steel sheet for a drawn can has a predetermined chemical composition and has a ferrite single-phase structure with a crystal grain size number of 11.0 or more, the sheet thickness is 0.15 to 0.50 mm, in an L direction of the steel sheet after an ageing treatment at 100° C. for one hour, an yield strength YP is 220 to 290 MPa, a tensile strength TS is 330 to 390 MPa, a total elongation EL is 32% or more, an yield point elongation YP-EL is 0%, an average plastic strain ratio rm is more than 1.35, and an in-plane anisotropy ?r is ?0.30 to +0.15.Type: GrantFiled: April 19, 2018Date of Patent: February 2, 2021Assignee: NIPPON STEEL CORPORATIONInventors: Masaharu Oka, Nobusato Kojima, Yuta Dairokuno, Michihiro Nono
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Patent number: 10815553Abstract: Provided is a galvannealed steel sheet having high strength and excellent deep drawability, and being further excellent in slab cracking resistance and secondary working embrittlement resistance. A base metal steel sheet of the galvannealed steel sheet has a chemical composition containing, in mass %: C: 0.0080% or less; Si: 0.7% or less; Mn: 1.0 to 2.5%; P: more than 0.030 to 0.048%; S: 0.025% or less; Al: 0.005 to 0.20%; N: 0.010% or less; Ti: 0.005 to 0.040%; Nb: 0.005 to 0.060%; and B: 0.0005 to 0.0030%, with the balance being Fe and impurities, satisfying Formula (1) to (4). A galvannealed layer contains 7 to 15 mass % of Fe. 25×P+4×Si?3.6??(1) B?X1?0.0005??(2) C?(12/93)×Nb?X2??0.Type: GrantFiled: August 22, 2016Date of Patent: October 27, 2020Assignee: NIPPON STEEL CORPORATIONInventors: Masaharu Oka, Nobusato Kojima, Tetsuya Okada
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Publication number: 20200048730Abstract: A steel sheet for a drawn can has a predetermined chemical composition and has a ferrite single-phase structure with a crystal grain size number of 11.0 or more, the sheet thickness is 0.15 to 0.50 mm, in an L direction of the steel sheet after an ageing treatment at 100° C. for one hour, an yield strength YP is 220 to 290 MPa, a tensile strength TS is 330 to 390 MPa, a total elongation EL is 32% or more, an yield point elongation YP-EL is 0%, an average plastic strain ratio rm is more than 1.35, and an in-plane anisotropy ?r is ?0.30 to +0.15.Type: ApplicationFiled: April 19, 2018Publication date: February 13, 2020Applicant: NIPPON STEEL CORPORATIONInventors: Masaharu OKA, Nobusato KOJIMA, Yuta DAIROKUNO, Michihiro NONO
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Patent number: 10336037Abstract: A galvanized steel sheet according to the present invention includes a steel sheet and a galvanizing layer which is formed on a surface of the steel sheet. The steel sheet includes as a chemical component, by mass %, C: more than 0.100% to 0.500%, Si: 0.0001% to less than 0.20%, Mn: more than 0.20% to 3.00%, Al: 3.0% to 10.0%, N: 0.0030% to 0.0100%, Ti: more than 0.100% to 1.000%, P: 0.00001% to 0.0200%, S: 0.00001% to 0.0100% and a remainder including Fe and impurities. The galvanizing layer includes as a chemical composition, by mass %, Fe: 0.01% to 15% and a remainder including Zn and impurities. The galvanized steel sheet has a specific gravity of 5.5 to less than 7.5.Type: GrantFiled: April 28, 2014Date of Patent: July 2, 2019Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Masaharu Oka, Nobuhiro Fujita, Manabu Takahashi, Riki Okamoto, Kenichiroh Matsumura
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Patent number: 10294551Abstract: A steel sheet including, by mass %, C: more than 0.100% and 0.500% or less, Si: 0.0001% or more and less than 0.20%, Mn: more than 0.20% and 0.50% or less, Al: 3.0% or more and 10.0% or less, N: 0.0030% or more and 0.0100% or less, Ti: more than 0.100% and 1.000% or less, P: 0.00001% or more and 0.0200% or less, S: 0.00001% or more and 0.0100% or less, and a remainder including Fe and impurities, in which a sum of a C content and a Ti content satisfies 0.200<C+Ti?1.500 by mass %, a product of an Al content and an Si content satisfies Al×Si?0.8 by mass %, and a specific gravity is 5.5 to less than 7.5.Type: GrantFiled: April 28, 2014Date of Patent: May 21, 2019Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Masaharu Oka, Nobuhiro Fujita, Manabu Takahashi, Riki Okamoto, Chisato Wakabayashi
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Publication number: 20180258514Abstract: Provided is a galvannealed steel sheet having high strength and excellent deep drawability, and being further excellent in slab cracking resistance and secondary working embrittlement resistance. A base metal steel sheet of the galvannealed steel sheet has a chemical composition containing, in mass %: C: 0.0080% or less; Si: 0.7% or less; Mn: 1.0 to 2.5%; P: more than 0.030 to 0.048%; S: 0.025% or less; Al: 0.005 to 0.20%; N: 0.010% or less; Ti: 0.005 to 0.040%; Nb: 0.005 to 0.060%; and B: 0.0005 to 0.0030%, with the balance being Fe and impurities, satisfying Formula (1) to (4). A galvannealed layer contains 7 to 15 mass % of Fe. 25×P+4×Si?3.6??(1) B?X1?0.0005??(2) C?(12/93)×Nb?X2??0.Type: ApplicationFiled: August 22, 2016Publication date: September 13, 2018Inventors: Masaharu OKA, Nobusato KOJIMA, Tetsuya OKADA
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Patent number: 9702031Abstract: The present invention provides a bake-hardenable high-strength cold-rolled steel sheet having excellent bake hardenability, cold aging resistance, and deep-drawability, and reduced planar anisotropy, containing chemical components in % by mass of: C: 0.0010% to 0.0040%, Si: 0.005% to 0.05%, Mn: 0.1% to 0.8%, P: 0.01% to 0.07%, S: 0.001% to 0.01%, Al: 0.01% to 0.08%, N: 0.0010% to 0.0050%, Nb: 0.002% to 0.020%, and Mo: 0.005% to 0.050%, a value of [Mn %]/[P %] being in the range of 1.6 to 45, where [Mn %] is an amount of Mn and [P %] is an amount of P, an amount of C in solid solution obtained from [C %]?(12/93)×[Nb %] being in the range of 0.0005% to 0.Type: GrantFiled: April 27, 2011Date of Patent: July 11, 2017Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Satoshi Akamatsu, Masaharu Oka
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Publication number: 20160075109Abstract: A galvanized steel sheet according to the present invention includes a steel sheet and a galvanizing layer which is formed on a surface of the steel sheet. The steel sheet includes as a chemical component, by mass %, C: more than 0.100% to 0.500%, Si: 0.0001% to less than 0.20%, Mn: more than 0.20% to 3.00%, Al: 3.0% to 10.0%, N: 0.0030% to 0.0100%, Ti: more than 0.100% to 1.000%, P: 0.00001% to 0.0200%, S: 0.00001% to 0.0100% and a remainder including Fe and impurities. The galvanizing layer includes as a chemical composition, by mass %, Fe: 0.01% to 15% and a remainder including Zn and impurities. The galvanized steel sheet has a specific gravity of 5.5 to less than 7.5.Type: ApplicationFiled: April 28, 2014Publication date: March 17, 2016Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Masaharu OKA, Nobuhiro FUJITA, Manabu TAKAHASHI, Riki OKAMOTO, Kenichiroh MATSUMURA
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Publication number: 20160040273Abstract: A steel sheet including, by mass %, C: more than 0.100% and 0.500% or less, Si: 0.0001% or more and less than 0.20%, Mn: more than 0.20% and 0.50% or less, Al: 3.0% or more and 10.0% or less, N: 0.0030% or more and 0.0100% or less, Ti: more than 0.100% and 1.000% or less, P: 0.00001% or more and 0.0200% or less, S: 0.00001% or more and 0.0100% or less, and a remainder including Fe and impurities, in which a sum of a C content and a Ti content satisfies 0.200<C+Ti?1.500 by mass %, a product of an Al content and an Si content satisfies Al×Si?0.8 by mass %, and a specific gravity is 5.5 to less than 7.5.Type: ApplicationFiled: April 28, 2014Publication date: February 11, 2016Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Masaharu OKA, Nobuhiro FUJITA, Manabu TAKAHASHI, Riki OKAMOTO, Chisato WAKABAYASHI
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Publication number: 20130240094Abstract: The present invention provides a bake-hardenable high-strength cold-rolled steel sheet having excellent bake hardenability, cold aging resistance, and deep-drawability, and reduced planar anisotropy, containing chemical components in % by mass of: C: 0.0010% to 0.0040%, Si: 0.005% to 0.05%, Mn: 0.1% to 0.8%, P: 0.01% to 0.07%, S: 0.001% to 0.01%, Al: 0.01% to 0.08%, N: 0.0010% to 0.0050%, Nb: 0.002% to 0.020%, and Mo: 0.005% to 0.050%, a value of [Mn %]/[P %] being in the range of 1.6 to 45, where [Mn %] is an amount of Mn and [P %] is an amount of P, an amount of C in solid solution obtained from [C %]?(12/93)×[Nb %] being in the range of 0.0005% to 0.Type: ApplicationFiled: April 27, 2011Publication date: September 19, 2013Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Satoshi Akamatsu, Masaharu Oka
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Patent number: 8500924Abstract: A high-strength steel plate includes the following composition: 0.18 to 0.23 mass % of C; 0.1 to 0.5 mass % of Si; 1.0 to 2.0 mass % of Mn; 0.020 mass % or less of P; 0.010 mass % or less of S; greater than 0.5 mass % and equal to or less than 3.0 mass % of Cu, 0.25 to 2.0 mass % of Ni; 0.003 to 0.10 mass % of Nb; 0.05 to 0.15 mass % of Al; 0.0003 to 0.0030 mass % of B; 0.006 mass % or less of N; and a balance composed of Fe and inevitable impurities. A weld crack sensitivity index Pcm of the high-strength steel plate is calculated by Pcm=[C]+[Si]/30+[Mn]/20+[Cu]/20+[Ni]/60+[Cr]/20+[Mo]/15+[V]/10+5[B], and is 0.39 mass % or less. The Ac3 transformation point is equal to or less than 850° C., the percentage value of a martensite structure is equal to or greater than 90%, the yield strength is equal to or greater than 1300 MPa, and the tensile strength is equal to or greater than 1400 MPa and equal to or less than 1650 MPa.Type: GrantFiled: October 13, 2009Date of Patent: August 6, 2013Assignee: Nippon Steel & Sumitomo Metal CorporationInventors: Tatsuya Kumagai, Akira Usami, Masaharu Oka
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Patent number: 8059214Abstract: Fluorescent tubes are arranged such that their arrangement spaces gradually become wider in central area than in edge areas, fluorescent tubes located in the vicinity of the central area of an arrangement direction are bent into chevron-shapes such that the central parts of the longitudinal directions of the fluorescent tubes become crests which provide access to a diffusion plate, respective two adjacent fluorescent tubes which are straight tubes are connected to one another, thereby constituting pseudo U-shaped tubes, and an AC power is supplied through terminals lined up along one side of a direct-type backlight device. A reflector plate is bent so as to match with the curvature of the bent fluorescent tubes, and is formed with a protrusion which allows the fluorescent tubes located in the vicinity of the central area of the arrangement direction to be raised so as to protrude toward a diffusion plate.Type: GrantFiled: March 26, 2007Date of Patent: November 15, 2011Assignee: Funai Electric Co., Ltd.Inventor: Masaharu Oka
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Publication number: 20110253271Abstract: A high-strength steel plate includes the following composition: 0.18 to 0.23 mass % of C; 0.1 to 0.5 mass % of Si; 1.0 to 2.0 mass % of Mn; 0.020 mass % or less of P; 0.010 mass % or less of S; greater than 0.5 mass % and equal to or less than 3.0 mass % of Cu, 0.25 to 2.0 mass % of Ni; 0.003 to 0.10 mass % of Nb; 0.05 to 0.15 mass % of Al; 0.0003 to 0.0030 mass % of B; 0.006 mass % or less of N; and a balance composed of Fe and inevitable impurities. A weld crack sensitivity index Pcm of the high-strength steel plate is calculated by Pcm=[C]+[Si]/30+[Mn]/20+[Cu]/20+[Ni]/60+[Cr]/20+[Mo]/15+[V]/10+5[B], and is 0.39 mass % or less. The Ac3 transformation point is equal to or less than 850° C., the percentage value of a martensite structure is equal to or greater than 90%, the yield strength is equal to or greater than 1300 MPa, and the tensile strength is equal to or greater than 1400 MPa and equal to or less than 1650 MPa.Type: ApplicationFiled: October 13, 2009Publication date: October 20, 2011Inventors: Tatsuya Kumagai, Akira Usami, Masaharu Oka
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Patent number: 7674004Abstract: Cold cathode fluorescent tubes of the first group are aligned widthwise in one side of an enclosure which is divided into two areas at a centerline running widthwise. Cold cathode fluorescent tubes of the second group are aligned widthwise in the other side of the enclosure. All of the cold cathode fluorescent tubes are symmetrically-placed with respect to the centerline running widthwise. The cold cathode fluorescent tubes positioned outside widthwise are inclined at ?2 so that the distance between each of the tubes and the aperture plane gradually decreases lengthwise from an edge toward the center of the enclosure. The cold cathode fluorescent tubes positioned inside widthwise are inclined at ?1 so that the distance between each of the tubes and the aperture plane gradually decreases lengthwise from an edge toward the center of the enclosure. The inclined angle ?1 is made greater than the inclined angle ?2.Type: GrantFiled: December 20, 2006Date of Patent: March 9, 2010Assignee: Funai Electric Co., Ltd.Inventor: Masaharu Oka
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Patent number: 7426022Abstract: A brightness measurement apparatus which includes a placement unit on which an object to be measured is placed, a measurement unit for measuring brightness or chromaticity from an upper surface of the object placed on the placement unit, a placement unit moving mechanism for moving the placement unit in an x-axis direction, and a measurement unit moving mechanism for moving the measurement unit in a y-axis direction orthogonal to the x-axis direction.Type: GrantFiled: November 27, 2006Date of Patent: September 16, 2008Assignee: Funai Electric Co., Ltd.Inventor: Masaharu Oka
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Publication number: 20070222905Abstract: Fluorescent tubes are arranged such that their arrangement spaces gradually become wider in central area than in edge areas, fluorescent tubes located in the vicinity of the central area of an arrangement direction are bent into chevron-shapes such that the central parts of the longitudinal directions of the fluorescent tubes become crests which provide access to a diffusion plate, respective two adjacent fluorescent tubes which are straight tubes are connected to one another, thereby constituting pseudo U-shaped tubes, and an AC power is supplied through terminals lined up along one side of a direct-type backlight device. A reflector plate is bent so as to match with the curvature of the bent fluorescent tubes, and is formed with a protrusion which allows the fluorescent tubes located in the vicinity of the central area of the arrangement direction to be raised so as to protrude toward a diffusion plate.Type: ApplicationFiled: March 26, 2007Publication date: September 27, 2007Applicant: Funai Electric Co., Ltd.Inventor: Masaharu Oka