Patents Assigned to Nippon Steel Corporation
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Patent number: 12215401Abstract: A grain-oriented electrical steel sheet of the present invention has a base steel sheet, an amorphous oxide layer formed on the base steel sheet, and a tension-insulation coating formed on the amorphous oxide layer, in which the base steel sheet contains, as a chemical composition, by mass %, C: 0.085% or less, Si: 0.80 to 7.00%, Mn: 1.50% or less, acid-soluble Al: 0.065% or less, S: 0.013% or less, Cu: 0 to 0.80%, N: 0 to 0.012%, P: 0 to 0.50%, Ni: 0 to 1.00%, Sn: 0 to 0.30%, and Sb: 0 to 0.30%, a remainder is Fe and an impurity, a surface glossiness Gs20(A) in a direction parallel to a rolling direction is 2.0 to 70, and a surface glossiness Gs20(B) in a direction perpendicular to the rolling direction is 2.0 to 70.Type: GrantFiled: January 16, 2020Date of Patent: February 4, 2025Assignee: NIPPON STEEL CORPORATIONInventors: Shinsuke Takatani, Yoshihiro Arita, Shunsuke Okumura, Shohji Nagano
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Patent number: 12215411Abstract: A coated steel member includes: a steel sheet substrate containing, as a chemical composition, by mass %, C: 0.25% to 0.65%, Si: 0.10% to 1.00%, Mn: 0.30% to 1.00%, P: 0.050% or less, S: 0.0100% or less, N: 0.010% or less, Ti: 0.010% to 0.100%, B: 0.0005% to 0.0100%, Nb: 0.02% to 0.10%, Mo: 0.10% to 1.00%, Cu: 0.15% to 1.00%, and Ni: 0.05% to 0.25%; and a coating formed on a surface of the steel sheet substrate and containing Al and Fe. The maximum Cu content in a range from the surface to a depth of 5.0 ?m is 150% or more of the Cu content of the steel sheet substrate.Type: GrantFiled: July 6, 2023Date of Patent: February 4, 2025Assignee: NIPPON STEEL CORPORATIONInventor: Shinichiro Tabata
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Patent number: 12215410Abstract: A grain oriented electrical steel sheet includes a base steel sheet, an oxide layer, and a tension-insulation coating. When the iron oxide layer is analyzed by a fourier transform infrared spectroscopy, an absorbance A650 at 650 cm?1 and an absorbance A1250 at 1250 cm?1 satisfy 0.2?A650/A1250?5.0. Moreover, a magnetic flux density B8 in a rolling direction of the grain oriented electrical steel sheet is 1.90 T or more.Type: GrantFiled: January 16, 2020Date of Patent: February 4, 2025Assignee: NIPPON STEEL CORPORATIONInventors: Ichiro Tanaka, Takashi Kataoka, Kazutoshi Takeda, Tomoya Suenaga, Yuki Kunita
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Publication number: 20250035139Abstract: To further improve corrosion resistance in the vicinity of a toe. A welded joint according to the present invention includes: a first steel sheet and a second steel sheet; and a weld bead zone formed by arc welding or laser welding, wherein at least one of the first steel sheet or the second steel sheet has a plating layer formed by a predetermined component and an oxide layer located on the plating layer in a non-heat-affected zone, and in a region from a position orthogonal to an extension direction of the weld bead zone from the toe and 1 mm in a direction separating from the toe to a position orthogonal to the extension direction from the toe and 2 mm in the direction separating from the toe, the plating layer has at least one of a ?-Zn phase, MgZn2 phase, Mg2Zn3 phase, or MgZn phase as a metal Zn-containing phase having a circle-equivalent diameter of 0.Type: ApplicationFiled: January 26, 2023Publication date: January 30, 2025Applicant: NIPPON STEEL CORPORATIONInventors: Masaaki URANAKA, Takuya MITSUNOBU, Masahiro MATSUBA, Toyomitsu NAKAMURA
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Publication number: 20250034686Abstract: Provided is a hot stamped body having a predetermined chemical composition and a microstructure comprising, by area ratio, at least one of martensite, bainite, and tempered martensite: 90% or more in total, wherein a standard deviation in grain size distribution of former austenite grains is 5.0 ?m or less, and a total amount of segregation of at least one of Mo, W, Ta, Re, Os, Ir, and Tc at the former austenite grain boundaries is 0.10 atm % or more.Type: ApplicationFiled: March 2, 2023Publication date: January 30, 2025Applicant: NIPPON STEEL CORPORATIONInventors: Yuri TODA, Kazuma ITO, Yuma ASADA
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Publication number: 20250033105Abstract: A method is disclosed for forming a curved portion with a small curvature radius in an original tube while suppressing wrinkles and buckling. The method includes placing the original tube between a first die and a second die, and pressing one or more times on the original tube by bringing the first die and the second die closer together and pressing the first die and second die against the original tube, wherein the original tube has a circular cross-sectional shape in at least a portion thereof, the first die has a first curved surface, the second die has a second curved surface, in one of the pressing, cross-sectioning and bending are simultaneously performed on at least the portion of the original tube by pressing the first die and second die against at least the portion of the original tube; in the cross-sectioning, the circular cross-sectional shape of the original tube is reduced in diameter, and a diameter reduction rate in one time of the pressing is more than 0% and less than 10%.Type: ApplicationFiled: December 28, 2022Publication date: January 30, 2025Applicant: NIPPON STEEL CORPORATIONInventors: Shohei TAMURA, Minoru KANEMARU, Rikuo KITAYAMA, Akira SHIRAI
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Publication number: 20250037912Abstract: This non-oriented electrical steel sheet includes a base material having a chemical composition containing, by mass %, C: 0 to 0.0050%, Si: 3.8 to 4.9%, Mn: 0.05 to 1.20%, sol. Al: more than 0.02% and 0.50% or less, P: 0 to 0.030%, S: 0 to 0.0030%, N: 0 to 0.0030%, Ti: 0% or more and less than 0.0050%, Nb: 0% or more and less than 0.0050%, Zr: 0% or more and less than 0.0050%, V: 0% or more and less than 0.0050%, Cu: 0% or more and less than 0.200%, Ni: 0% or more and less than 0.500%, Sn: 0 to 0.100%, Sb: 0 to 0.100%, and the balance: Fe and impurities, wherein the non-oriented electrical steel sheet satisfies [4.3?Si+sol. Al+0.5×Mn?5.0], [B50(0°)?B50(45°)?0.16], and [B50(0°)+2×B50(45°)+B50(90°)/4?1.57], and has tensile strength of 580 MPa or greater.Type: ApplicationFiled: February 17, 2022Publication date: January 30, 2025Applicant: NIPPON STEEL CORPORATIONInventors: Hiroyoshi YASHIKI, Yoshiaki NATORI, Kazutoshi TAKEDA, Ichiro TANAKA, Yoshihiro ARITA, Hiroki HORI, Wataru OHASHI
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Publication number: 20250033137Abstract: A method for manufacturing a projection weld joint according to the present disclosure includes: pressing a projection portion of a steel member having the projection portion on a plane onto a surface of a hot-stamping steel sheet, wherein the hot-stamping steel sheet has an Al-based plating layer on the surface and has a tensile strength of 1.5 GPa or more; applying first energization to the hot-stamping steel sheet, the projection portion, and the steel member to make the projection portion serve as a projection weld; quenching the projection weld; and applying second energization to the quenched projection weld to temper edges of the projection weld while keeping a central part of the projection weld quenched.Type: ApplicationFiled: March 20, 2023Publication date: January 30, 2025Applicant: NIPPON STEEL CORPORATIONInventors: Masanori YASUYAMA, Yasuaki NAITO, Takashi IMAMURA, Masatoshi TOKUNAGA, Naoaki SHIMADA
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Patent number: 12209300Abstract: An automobile undercarriage part of the present invention has a welded joint formed by base steel plate, wherein the chemical composition of a weld metal contains, with respect to a total mass of the weld metal, by mass %, C: 0.02% to 0.30%, Si: 0.10% to less than 1.0%, Mn: 1.2% to 3.0%, Al: 0.002% to 0.30%, Ti: 0.005% to 0.30%, P: more than 0% to 0.015%, and S: more than 0% to 0.030%, the following formula (1A), formula (1B), formula (2), and formula (3) are satisfied, and slag in a toe portion of the fillet weld satisfies a formula (4). [Al]+[Ti]>0.05??Formula (1A) [Ti]/[Al]>0.9??Formula(1B) 7×[Si]+7×[Mn]?112×[Ti]?30×[Al]?12??Formula (2) 2.0<[Si]+[Mn]??Formula (3) [Ti content on slag surface]>[Si content on slag surface]??Formula (4).Type: GrantFiled: March 27, 2020Date of Patent: January 28, 2025Assignee: NIPPON STEEL CORPORATIONInventors: Kenichiro Otsuka, Masafumi Azuma, Yoichiro Mori, Shinji Kodama, Masahiro Matsuba
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Patent number: 12211633Abstract: What is provided is a non-oriented electrical steel sheet having a chemical composition in which, by mass %, C: 0.010% or less, Si: 1.50% to 4.00%, sol. Al: 0.0001% to 1.0%, S: 0.010% or less, N: 0.010% or less and one or a plurality of elements selected from the group consisting of Mn, Ni, Co, Pt, Pb, Cu and Au: 2.50% to 5.00% in total with a remainder including Fe and impurities, in which a recrystallization rate is 1% to 99% in a metallographic structure, a sheet thickness is 0.50 mm or less, and, in the case of measuring a magnetic flux density B50 after annealing the non-oriented electrical steel sheet at 800° C. for two hours, a magnetic flux density B50 in a 45° direction with respect to a rolling direction is 1.75 T or more.Type: GrantFiled: November 13, 2020Date of Patent: January 28, 2025Assignee: NIPPON STEEL CORPORATIONInventors: Tesshu Murakawa, Miho Tomita, Hiroshi Fujimura, Satoshi Kano
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Publication number: 20250027178Abstract: A facility for producing reduced iron includes: a granulation apparatus that granulates raw material fine powder that contains iron and has a median diameter of 50 ?m or less into granular powder in a fluidized bed formed by fluidizing medium particles that do not thermally decompose during fluidization; and a reduction apparatus that reduces at least the granular powder in the fluidized bed formed by fluidizing the granular powder.Type: ApplicationFiled: November 30, 2022Publication date: January 23, 2025Applicant: NIPPON STEEL CORPORATIONInventors: Shoji USHIO, Kimihito SUZUKI, Takashi IIJIMA
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Publication number: 20250027186Abstract: Provided is a plated steel sheet comprising a base steel sheet and a plating layer formed on a surface of the base steel sheet, wherein the plating layer has a predetermined chemical composition, and when measuring the plating layer by glow discharge spectroscopy (GDS), a ratio of “Al concentration at center of plating layer”/“Al concentration at position of plating layer where Fe concentration is 50% of base steel sheet” is 0.10 to 1.50.Type: ApplicationFiled: December 21, 2022Publication date: January 23, 2025Applicant: NIPPON STEEL CORPORATIONInventors: Takuya MITSUNOBU, Hiroshi TAKEBAYASHI
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Patent number: 12203157Abstract: This hot-rolled steel sheet has a predetermined chemical composition, in which a metallographic structure contains, by area %, 3.0% or more of retained austenite, has a ratio L52/L7 of a length L52 of a grain boundary having a crystal misorientation of 52° to a length L7 of a grain boundary having a crystal misorientation of 7° about a <110> direction of more than 0.18, has a standard deviation of a Mn concentration of 0.60 mass % or less, and has a tensile strength of 1180 MPa or more.Type: GrantFiled: January 30, 2020Date of Patent: January 21, 2025Assignee: NIPPON STEEL CORPORATIONInventors: Koutarou Hayashi, Hiroshi Shuto, Kazumasa Tsutsui, Hiroshi Kaido
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Patent number: 12203148Abstract: This hot-rolled steel sheet has a predetermined chemical composition, in a microstructure at a ¼ position of a sheet thickness in a sheet thickness direction from a surface, a primary phase is bainite, a secondary phase is martensite or a martensite-austenite mixed phase, an average grain size of the secondary phase is 1.5 ?m or less, an average grain size of particles having grain diameters that are largest 10% or less out of all particles in the secondary phase is 2.5 ?m or less, a pole density in a (110)<112> orientation is 3.0 or less, and, in a microstructure from the surface to a 1/16 position of the sheet thickness in the sheet thickness direction from the surface, a pole density in a (110)<1-11> orientation is 3.0 or less.Type: GrantFiled: December 8, 2020Date of Patent: January 21, 2025Assignee: NIPPON STEEL CORPORATIONInventors: Daisuke Ito, Shohei Yabu, Takeshi Toyoda
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Patent number: 12202025Abstract: This press-formed article includes: a top sheet portion; a sidewall continuing to the top sheet portion via a convex ridge line portion; a flange continuing to the sidewall via a concaved ridge line portion; and an outward flange continuing from an edge portion of the top sheet portion to an edge portion of the flange, via an edge portion of the convex ridge line portion, an edge portion of the sidewall, and an edge portion of the concaved ridge line portion, wherein in the same unit, an average thickness TAve, a minimum thickness TMin, and a maximum thickness TMax of the outward flange satisfy Equation 1 and Equation 2. 0.8×TAve?TMin<TAve??(Equation 1) TAve<TMax?1.Type: GrantFiled: September 7, 2023Date of Patent: January 21, 2025Assignee: NIPPON STEEL CORPORATIONInventors: Yasuharu Tanaka, Misao Ogawa, Takashi Miyagi, Toshimitsu Aso, Hiroyuki Tanoue, Ryo Kuroda
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Patent number: 12202075Abstract: A welded joint comprising: a pair of steel base materials having a sheet thickness of 0.4 to 4.0 mm, and at least one of which has a tensile strength of 780 MPa or more; and a weld metal that welds the pair of steel base materials, wherein, when the weld metal is seen in plan view, a weld toe of the weld metal has peaks and valleys, an average distance in a direction orthogonal to a weld line direction between a top point of a peak and a bottom point of a valley that are adjacent to one another is 3.0 mm or less, and an average number of a total of peaks and valleys, at which the distance in the direction orthogonal to the weld line direction between the top point of the peak and the bottom point of the valley that are adjacent to one another is 0.1 mm to 3.0 mm, is 2 to 30/15 mm, and an automobile component having the welded joint.Type: GrantFiled: October 5, 2020Date of Patent: January 21, 2025Assignee: NIPPON STEEL CORPORATIONInventors: Kazuki Matsuda, Shinji Kodama
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Publication number: 20250022639Abstract: Provided is a non-oriented electrical steel sheet including a base steel sheet and an insulating coating film formed on a surface of the base steel sheet, wherein the base steel sheet has a chemical composition containing, in mass %, C: 0.0030% or less, Si: 3.2 to 6.5%, Mn: 0.05 to 3.5%, P: 0.005 to 0.10%, S: 0.0030% or less, Al: 1.0% of less, Ti: 0.0030% or less, B: 0.0010% or less, Mo: 0.030% or less, V: 0.0010% or less, Ca: 0 to 0.0050%, Mg: 0 to 0.0050%, and REM: 0 to 0.0050%, with a balance being Fe and impurities, and satisfying [S-5/3×Mg-4/5×Ca-1/4×REM<0.0005], and the insulating coating film has a chemical composition satisfying [[M]-[C]+1/2×[O]>0].Type: ApplicationFiled: October 12, 2022Publication date: January 16, 2025Applicant: NIPPON STEEL CORPORATIONInventors: Yoshiaki NATORI, Kazutoshi TAKEDA, Hiroyoshi YASHIKI, Minako FUKUCHI
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Publication number: 20250019808Abstract: This hot-rolled steel sheet has a microstructure comprising bainite: 55 to 95%, retained austenite: 5 to 30%, fresh martensite: 5% or less, ferrite: 5% or less, and pearlite: 5% or less, in a texture at a region from a surface to a ? thickness depth from the surface, a pole density of {110}<111> orientation is 3.0 or less, and an arithmetic average roughness Ra of the surface after pickling is less than 1.2 ?m.Type: ApplicationFiled: December 6, 2022Publication date: January 16, 2025Applicant: NIPPON STEEL CORPORATIONInventors: Mutsumi SAKAKIBARA, Hiroshi SHUTO, Hiroshi TANEI
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Publication number: 20250019810Abstract: This steel member has a predetermined chemical composition, in which, when a ¼ position of a thickness in a thickness direction from a surface is defined as a ¼ depth position, a metallographic structure at the ¼ depth position includes 90% or more of martensite by volume fraction, in the metallographic structure at the ¼ depth position, L49-56°/L4-12°, which is a ratio of a length L49-56° of grain boundaries having an angle of rotation of 49° to 56° to a length L4-12° of grain boundaries having an angle of rotation of 4° to 12° about a <011> direction as a rotation axis, among grain boundaries of grains having a body-centered structure, is 1.10 or more, and a tensile strength of the steel member is more than 1.500 MPa.Type: ApplicationFiled: November 29, 2022Publication date: January 16, 2025Applicant: NIPPON STEEL CORPORATIONInventors: Shinichiro TABATA, Kazuhisa KUSUMI
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Publication number: 20250019788Abstract: An annealing separator used for manufacture of the grain-oriented electrical steel sheet according to the present invention contains MgO, at least one or more types of compounds of metal selected from a group comprised of Y, La, and Ce, and at least one or more types of compounds of metal selected from a group comprised of Ti, Zr, and Hf, wherein when a content of the MgO in the annealing separator is defined as 100% by mass %, a total content of the compounds of metal selected from a group comprised of Y, La, and Ce converted to oxides is 0.5 to 8.0%, a total content of the compounds of metal selected from a group comprised of Ti, Zr, and Hf converted to oxides is 0.5 to 10.0%, further, a total of a total content of the compounds of metal selected from a group comprised of Y, La, and Ce converted to oxides and a total content of the compounds of metal selected from a group comprised of Ti, Zr, and Hf converted to oxides is 2.0 to 14.Type: ApplicationFiled: September 26, 2024Publication date: January 16, 2025Applicant: NIPPON STEEL CORPORATIONInventors: Ryutaro YAMAGATA, Ichiro TANAKA