Patents by Inventor Kazunari Imakawa
Kazunari Imakawa 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: 20230160045Abstract: An austenitic stainless steel consists of 0.010 to 0.200% by mass of C, 2.00% by mass or less of Si, 3.00% by mass or less of Mn, 0.035% by mass or less of P, 0.0300% by mass or less of S, 6.00 to 14.00% by mass of Ni, 20.0 to 26.0% by mass of Cr, 3.00% by mass or less of Mo, 0.01 to 3.00% by mass of Cu, 1.000% by mass of less of Ti, 0.200% by mass or less of Al, 0.1000% by mass or less of Ca, 0.100 to 0.250% by mass of N, and 0.0080% by mass or less of 0, the balance being Fe and impurities.Type: ApplicationFiled: March 29, 2021Publication date: May 25, 2023Applicant: NIPPON STEEL Stainless Steel CorporationInventors: Kotaro SEKIMUKAI, Kazunari IMAKAWA
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Patent number: 11326236Abstract: Provided is a black stainless steel sheet that has excellent weldability, that can ensure good toughness and corrosion resistance, and that can maintain the blackness of the surface thereof, even after being welded. This black ferrite-based stainless steel sheet having excellent weldability includes, as a base, a stainless steel containing, in mass %, 0.020% or less of C, 1.0% or less of Si, 0.35% or less of Mn, 0.04% or less of P, 0.005% or less of S, 11-25% of Cr, 1.0% or less of Mo, 0.020% or less of N, 0.4% or less of Al, 10(C+N) to 0.3% of Ti, 0.05% or less of Nb, and 0.01% or less of O, and has a surface in which an oxide coating is formed on the base, wherein the surface has a lightness index (L*) satisfying L*?45, chromaticity indices (a*, b*) satisfying ?5?a*?5 and ?5?b*?5, and a blackness (E) satisfying E=(L*2+a*2+b*2)1/2?45.Type: GrantFiled: January 26, 2018Date of Patent: May 10, 2022Assignee: NIPPON STEEL STAINLESS STEEL CORPORATIONInventors: Yoshikazu Tai, Tomoaki Saida, Kazunari Imakawa, Satoshi Suzuki
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Patent number: 10995888Abstract: A Ti-containing ferritic stainless steel sheet for an exhaust pipe flange member has a composition containing, in mass percentage, from 0.003 to 0.030% of C, 2.0% or less of S i, 2.0% or less of Mn, 0.050% or less of P, 0.040% or less of S, from 10.0 to 19.0% of Cr, 0.030% or less of N, from 0.07 to 0.50% of Ti, from 0.010 to 0.20% of Al, from 0 to 1.50% of Mo, and from 0 to 0.0030% of B, with the balance Fe and unavoidable impurities, has a K value of 150 or more, has a sheet surface hardness of 170 HV or less, and has a sheet thickness of from 5.0 to 11.0 mm. The K value equals ?0.07×Cr?6790×Free(C+N)?1.44×d+267, wherein Free(C+N) corresponds to the solid-dissolved (C+N) concentration (% by mass), and d represents an average crystal grain diameter (?m).Type: GrantFiled: February 7, 2017Date of Patent: May 4, 2021Assignee: NIPPON STEEL STAINLESS STEEL CORPORATIONInventors: Seiji Mitsunaga, Nobuhisa Ebihama, Yasuhiro Ehara, Kazunari Imakawa
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Publication number: 20200277690Abstract: A ferritic stainless steel raw material steel sheet for annealing and cold rolling, has a composition containing, in mass percentage, from 0.004 to 0.030% of C, 1.50% or less of Si, 1.50% or less of Mn, 0.040% or less of P, 0.010% or less of S, from 12.0 to 25.0% of Cr, from 0.005 to 0.025% of N, from 0.20 to 0.80% of Nb, 0.10% or less of Al, from 0 to 3.0% of Mo, from 0 to 2.0% of Cu, from 0 to 2.0% of Ni, from 0 to 0.30% of Ti, from 0 to 0.0030% of B, and the balance of Fe, with unavoidable impurities. An existing amount of a Nb-containing precipitate of 0.20% by mass or more is provided. The raw material steel sheet is subjected to annealing at a temperature of from 900 to 1,100° C., and then subjected to cold rolling and finish annealing.Type: ApplicationFiled: March 28, 2017Publication date: September 3, 2020Inventors: Yutaka YAKUSHIJIN, Akira HIRONAKA, Kazunari IMAKAWA
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Publication number: 20200255919Abstract: The hot-rolled Nb-containing ferritic stainless steel sheet of the present invention has a composition containing C: 0.030 mass % or less, Si: 2.00 mass % or less, Mn: 2.00 mass % or less, P: 0.050 mass % or less, S: 0.040 mass % or less, Cr: 10.00 mass % to 25.00 mass %, N: 0.030 mass % or less and Nb: 0.01 mass % to 0.80 mass %, with the balance being made up of Fe and unavoidable impurities. In this hot-rolled Nb-containing ferritic stainless steel sheet, the precipitation amount of Nb carbonitrides is 0.2 mass % or more, and the number of Laves phases having a grain size of 0.1 ?m or less is 10 or fewer per 10 ?m2 of surface area.Type: ApplicationFiled: April 10, 2020Publication date: August 13, 2020Applicant: NIPPON STEEL Stainless Steel CorporationInventors: Yutaka YAKUSHIJIN, Akira HIRONAKA, Kazunari IMAKAWA
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Publication number: 20200232075Abstract: Provided is a black stainless steel sheet that has excellent weldability, that can ensure good toughness and corrosion resistance, and that can maintain the blackness of the surface thereof, even after being welded. This black ferrite-based stainless steel sheet having excellent weldability includes, as a base, a stainless steel containing, in mass %, 0.020% or less of C, 1.0% or less of Si, 0.35% or less of Mn, 0.04% or less of P, 0.005% or less of S, 11-25% of Cr, 1.0% or less of Mo, 0.020% or less of N, 0.4% or less of Al, 10(C+N) to 0.3% of Ti, 0.05% or less of Nb, and 0.01% or less of 0, and has a surface in which an oxide coating is formed on the base, wherein the surface has a lightness index (L*) satisfying L*<45, chromaticity indices (a*, b*) satisfying ?5?a*?5 and ?5?b*?5, and a blackness (E) satisfying E=(L*2+a*2+b*2)1/2?45.Type: ApplicationFiled: January 26, 2018Publication date: July 23, 2020Inventors: Yoshikazu TAI, Tomoaki SAIDA, Kazunari IMAKAWA, Satoshi SUZUKI
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Patent number: 10695874Abstract: Provided is a stainless steel material for a diffusion bonding jig in which deformation of bonding members is suppressed while maintaining diffusion bonding properties of the bonding members, and in which releasability (detachability of a bonding member from a release member) after diffusion bonding treatment is excellent. An embodiment of the present invention provides a stainless steel material for a diffusion bonding jig having excellent deformation suppressibility and releasability, the material being a stainless steel material including 1.5 mass % or more of Si, and a ratio (Fr/Fp) of the high-temperature strength (Fr) of the stainless steel material at 1000° C. to the high-temperature strength (Fp) of a bonding member at 1000° C. being 0.9 or more, the bonding member to be bonded by diffusion bonding. The stainless steel material preferably includes C: 0.1 mass % or less, Si: 1.5 to 5.0 mass %, Mn: 2.5 mass % or less, P: 0.06 mass % or less, S: 0.02 mass % or less, Ni: 8.0 to 15.0 mass %, Cr: 13.Type: GrantFiled: December 13, 2018Date of Patent: June 30, 2020Assignee: NISSHIN STEEL CO., LTD.Inventors: Yoshiaki Hori, Kazunari Imakawa
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Patent number: 10670350Abstract: Provided is a method of manufacturing a heat exchanger by diffusion bonding in which deformation of bonding members as stainless steel plates is suppressed, and releasability (detachability of a bonding member from a release member) after diffusion bonding treatment is excellent. Provided is a method of manufacturing a heat exchanger, the method including layering a plurality of bonding members 1 made of stainless steel, and applying heat and pressure to effect diffusion bonding of the bonding members 1, in which release members 3 are arranged on the both surface sides of the bonding members 1, and holding jigs 4 are arranged so as to sandwich the bonding members 1 through the release members 3, and pressing is then performed through the holding jigs 4 with a pressure device, and in which the diffusion bonding is performed using a combination of the release members 3 and the bonding members 1, the release members 3 including a steel material containing 1.Type: GrantFiled: December 13, 2018Date of Patent: June 2, 2020Assignee: NIPPON STEEL NISSHIN CO., LTD.Inventors: Yoshiaki Hori, Kazunari Imakawa
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Patent number: 10570979Abstract: A ferritic stainless steel material excellent in vibration damping capability has a composition containing, by mass %, from 0.001 to 0.04% of C, from 0.1 to 2.0% of Si, from 0.1 to 1.0% of Mn, from 0.01 to 0.6% of Ni, from 10.5 to 20.0% of Cr, from 0.5 to 5.0% of Al, from 0.001 to 0.03% of N, from 0 to 0.8% of Nb, from 0 to 0.5% of Ti, from 0 to 0.3% of Cu, from 0 to 0.3% of Mo, from 0 to 0.3% of V, from 0 to 0.3% of Zr, from 0 to 0.6% of Co, from 0 to 0.1% of REM, from 0 to 0.1% of Ca, the balance of Fe and unavoidable impurities, and has ferrite single phase matrix with crystal grains of average crystal grain diameter of from 0.3 to 3.0 mm and a residual magnetic flux density of 45 mT or less.Type: GrantFiled: August 10, 2016Date of Patent: February 25, 2020Assignee: NIPPON STEEL NISSHIN CO., LTD.Inventors: Yoshiaki Hori, Kazunari Imakawa, Satoshi Suzuki
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Publication number: 20190382874Abstract: The present invention relates to a ferritic stainless steel containing 0.03% by mass or less of C; from 0.1 to 0.8% by mass of Si; 1.0% by mass or less of Mn; 0.04% by mass or less of P; 0.01% by mass or less of S; 0.5% by mass or less of Ni; from 12.0 to 15.0% by mass of Cr; 0.03% by mass or less of N; from 0.1 to 0.5% by mass of Nb; from 0.8 to 1.5% by mass of Cu; and 0.1% by mass or less of Al, the balance being Fe and unavoidable impurities, the ferritic stainless steel having a ? max of 55 or less, as represented by the following equation (1): ? max=420C?11.5Si+7Mn+23Ni?11.5Cr+470N+9Cu?52Al+189??(1), in which C, Si, Mn, Ni, Cr, N, Cu and Al mean % by mass of the corresponding elements.Type: ApplicationFiled: September 5, 2017Publication date: December 19, 2019Inventors: Yoshihiro OKA, Yoshitomo FUJIMURA, Kazunari IMAKAWA
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Patent number: 10502507Abstract: A plate-type heat exchanger may include a housing. The housing may include a plurality of rectangular plate-like components that are box-like components each having the same shape and having a standing wall section along a peripheral edge. One of the box-like components may be layered on another components reversed in the horizontal direction to form a layered structure having an upper layer component and a lower layer component such that an upper portion of a standing wall section of the lower layer component of the layered structure is fit into a lower portion of a standing wall section of the upper layer component of the layered structure. The angle (?) of the standing wall sections may be ??30°, and at least a portion of a contact region between the upper portion and the lower portion may be joined by solid phase diffusion bonding.Type: GrantFiled: February 18, 2015Date of Patent: December 10, 2019Assignee: NIPPON STEEL NISSHIN CO., LTD.Inventors: Atsushi Sugama, Manabu Oku, Yoshiaki Hori, Kazunari Imakawa
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Publication number: 20190285367Abstract: Provided is a method of manufacturing a heat exchanger by diffusion bonding in which deformation of bonding members as stainless steel plates is suppressed, and releasability (detachability of a bonding member from a release member) after diffusion bonding treatment is excellent. Provided is a method of manufacturing a heat exchanger, the method including layering a plurality of bonding members 1 made of stainless steel, and applying heat and pressure to effect diffusion bonding of the bonding members 1, in which release members 3 are arranged on the both surface sides of the bonding members 1, and holding jigs 4 are arranged so as to sandwich the bonding members 1 through the release members 3, and pressing is then performed through the holding jigs 4 with a pressure device, and in which the diffusion bonding is performed using a combination of the release members 3 and the bonding members 1, the release members 3 including a steel material containing 1.Type: ApplicationFiled: December 13, 2018Publication date: September 19, 2019Inventors: Yoshiaki HORI, Kazunari IMAKAWA
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Publication number: 20190283189Abstract: Provided is a stainless steel material for a diffusion bonding jig in which deformation of bonding members is suppressed while maintaining diffusion bonding properties of the bonding members, and in which releasability (detachability of a bonding member from a release member) after diffusion bonding treatment is excellent. An embodiment of the present invention provides a stainless steel material for a diffusion bonding jig having excellent deformation suppressibility and releasability, the material being a stainless steel material including 1.5 mass % or more of Si, and a ratio (Fr/Fp) of the high-temperature strength (Fr) of the stainless steel material at 1000° C. to the high-temperature strength (Fp) of a bonding member at 1000° C. being 0.9 or more, the bonding member to be bonded by diffusion bonding. The stainless steel material preferably includes C: 0.1 mass % or less, Si: 1.5 to 5.0 mass %, Mn: 2.5 mass % or less, P: 0.06 mass % or less, S: 0.02 mass % or less, Ni: 8.0 to 15.0 mass %, Cr: 13.Type: ApplicationFiled: December 13, 2018Publication date: September 19, 2019Inventors: Yoshiaki HORI, Kazunari IMAKAWA
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Publication number: 20190154177Abstract: A Ti-containing ferritic stainless steel sheet for an exhaust pipe flange member has a composition containing, in mass percentage, from 0.003 to 0.030% of C, 2.0% or less of S i, 2.0% or less of Mn, 0.050% or less of P, 0.040% or less of S, from 10.0 to 19.0% of Cr, 0.030% or less of N, from 0.07 to 0.50% of Ti, from 0.010 to 0.20% of Al, from 0 to 1.50% of Mo, and from 0 to 0.0030% of B, with the balance Fe and unavoidable impurities, has a K value of 150 or more, has a sheet surface hardness of 170 HV or less, and has a sheet thickness of from 5.0 to 11.0 mm. The K value equals ?0.07×Cr?6790×Free(C+N)?1.44×d+267, wherein Free(C+N) corresponds to the solid-dissolved (C+N) concentration (% by mass), and d represents an average crystal grain diameter (?m).Type: ApplicationFiled: February 7, 2017Publication date: May 23, 2019Inventors: Seiji MITSUNAGA, Nobuhisa EBIHAMA, Yasuhiro EHARA, Kazunari IMAKAWA
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Publication number: 20190093192Abstract: A Ti-containing ferritic stainless steel sheet having a large gauge thickness and excellent toughness has a chemical composition containing, in terms of percentage by mass, from 0.003 to 0.030% of C, 2.0% or less of Si, 2.0% or less of Mn, 0.050% or less of P, 0.040% or less of S, from 10.0 to 19.0% of Cr, 0.030% or less of N, from 0.07 to 0.50% of Ti, from 0.010 to 0.20% of Al, from 0 to 1.50% of Mo, and from 0 to 0.0030% of B, the balance of Fe and unavoidable impurities. The steel has a K value defined by the following expression of 150 or more: K value=?0.07?Cr?6790?Free(C+N)?1.44?d+267, and having a sheet thickness of from 5.0 to 11.0 mm. Herein, Free(C+N) corresponds to the solid-dissolved (C+N) concentration (% by mass), and d represents an average crystal grain diameter (?m).Type: ApplicationFiled: January 24, 2017Publication date: March 28, 2019Applicant: NISSHIN STEEL CO., LTD.Inventors: Seiji MITSUNAGA, Nobuhisa EBIHAMA, Yasuhiro EHARA, Kazunari IMAKAWA
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Publication number: 20190039165Abstract: A method for welding austenitic stainless steel sheets, in which welding defects do not easily occur. Austenitic stainless steel sheets each with a sheet thickness of 0.6 to 1.0 mm, which each contain, in terms of mass %, 0.08% or less of C, 1.5 to 4.0% of Si, 2.0% or less of Mn, 0.04% or less of P, 0.01% or less of S, 16.0 to 22.0% of Cr, 10.0 to 14.0% of Ni, and 0.08% or less of N, and contain at least one of Nb and Ti in an amount of 1.0% or less in total, with the rest including Fe and inevitable impurities, are overlapped and the overlapped portion is welded by arc welding. In addition, the back side of a deposited portion is cooled from 1200° C. to 900° C. at a cooling rate of 110° C./sec or higher.Type: ApplicationFiled: August 30, 2016Publication date: February 7, 2019Applicant: NISSHIN STEEL CO., LTD.Inventors: Yoshitomo FUJIMURA, Kazunari IMAKAWA, Osamu YAMAMOTO, Manabu OKU, Isamu HAYAKAWA, Hiroaki SHICHI, Yoshihide NARUSE
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Patent number: 10161524Abstract: To provide a heat resistant metal gasket that is controlled to have a strength level (ordinary temperature hardness) capable of facilitating processing, and has excellent gas leak resistance. An austenitic stainless steel sheet for a metal gasket, having a chemical composition containing from 0.015 to 0.200% of C, from 1.50 to 5.00% of Si, from 0.30 to 2.50% of Mn, from 7.0 to 17.0% of Ni, from 13.0 to 23.0% of Cr, and from 0.005 to 0.250% of N, all in terms of percentage by mass, containing, as necessary, at least one of Mo, Cu, Nb, Ti, V, Zr, W, Co, B, Al, REM (rare-earth element except for Y), Y, Ca and Mg, with the balance of Fe and unavoidable impurities, having an ordinary temperature hardness of 430 HV or less, having a half width of a peak of an austenite crystal (311) plane in an X-ray diffraction pattern of a cross section perpendicular to a sheet thickness direction of from 0.10 to 1.60°, and having a surface roughness Ra of 0.30 ?mm or less.Type: GrantFiled: March 16, 2015Date of Patent: December 25, 2018Assignee: NISSHIN STEEL CO., LTD.Inventors: Naohito Kumano, Kazunari Imakawa, Manabu Oku
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Publication number: 20180363089Abstract: The hot-rolled Nb-containing ferritic stainless steel sheet of the present invention has a composition containing C: 0.030 mass % or less, Si: 2.00 mass % or less, Mn: 2.00 mass % or less, P: 0.050 mass % or less, S: 0.040 mass % or less, Cr: 10.00 mass % to 25.00 mass %, N: 0.030 mass % or less and Nb: 0.01 mass % to 0.80 mass %, with the balance being made up of Fe and unavoidable impurities. In this hot-rolled Nb-containing ferritic stainless steel sheet, the precipitation amount of Nb carbonitrides is 0.2 mass % or more, and the number of Laves phases having a grain size of 0.1 ?m or less is 10 or fewer per 10 ?m2 of surface area.Type: ApplicationFiled: January 31, 2017Publication date: December 20, 2018Applicant: NISSHIN STEEL CO., LTD.Inventors: Yutaka YAKUSHIJIN, Akira HIRONAKA, Kazunari IMAKAWA
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Publication number: 20180304433Abstract: A stainless steel pipe may be provided which exhibits excellent corrosion resistance so as not to rust at an early stage even in a waterfront environment affected by sea salt particles. The stainless steel pipe may have a polishing mark on a surface, an oxide film exhibiting color is not present on the surface, and an average number of surface defects including covering by a metal base of 5 ?m or more on the surface is suppressed to 5 or fewer per 0.01 mm2.Type: ApplicationFiled: September 6, 2016Publication date: October 25, 2018Inventors: Tomoaki SAIDA, Yoshikazu TAI, Kazunari IMAKAWA
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Publication number: 20180238410Abstract: A ferritic stainless steel material excellent in vibration damping capability has a composition containing, by mass %, from 0.001 to 0.04% of C, from 0.1 to 2.0% of Si, from 0.1 to 1.0% of Mn, from 0.01 to 0.6% of Ni, from 10.5 to 20.0% of Cr, from 0.5 to 5.0% of Al, from 0.001 to 0.03% of N, from 0 to 0.8% of Nb, from 0 to 0.5% of Ti, from 0 to 0.3% of Cu, from 0 to 0.3% of Mo, from 0 to 0.3% of V, from 0 to 0.3% of Zr, from 0 to 0.6% of Co, from 0 to 0.1% of REM, from 0 to 0.1% of Ca, the balance of Fe and unavoidable impurities, and has ferrite single phase matrix with crystal grains of average crystal grain diameter of from 0.3 to 3.0 mm and a residual magnetic flux density of 45 mT or less.Type: ApplicationFiled: August 10, 2016Publication date: August 23, 2018Inventors: Yoshiaki HORI, Kazunari IMAKAWA, Satoshi SUZUKI