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).

  • Publication number: 20230160045
    Abstract: 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: Application
    Filed: March 29, 2021
    Publication date: May 25, 2023
    Applicant: NIPPON STEEL Stainless Steel Corporation
    Inventors: Kotaro SEKIMUKAI, Kazunari IMAKAWA
  • Patent number: 11326236
    Abstract: 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: Grant
    Filed: January 26, 2018
    Date of Patent: May 10, 2022
    Assignee: NIPPON STEEL STAINLESS STEEL CORPORATION
    Inventors: Yoshikazu Tai, Tomoaki Saida, Kazunari Imakawa, Satoshi Suzuki
  • Patent number: 10995888
    Abstract: 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: Grant
    Filed: February 7, 2017
    Date of Patent: May 4, 2021
    Assignee: NIPPON STEEL STAINLESS STEEL CORPORATION
    Inventors: Seiji Mitsunaga, Nobuhisa Ebihama, Yasuhiro Ehara, Kazunari Imakawa
  • Publication number: 20200277690
    Abstract: 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: Application
    Filed: March 28, 2017
    Publication date: September 3, 2020
    Inventors: Yutaka YAKUSHIJIN, Akira HIRONAKA, Kazunari IMAKAWA
  • Publication number: 20200255919
    Abstract: 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: Application
    Filed: April 10, 2020
    Publication date: August 13, 2020
    Applicant: NIPPON STEEL Stainless Steel Corporation
    Inventors: Yutaka YAKUSHIJIN, Akira HIRONAKA, Kazunari IMAKAWA
  • Publication number: 20200232075
    Abstract: 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: Application
    Filed: January 26, 2018
    Publication date: July 23, 2020
    Inventors: Yoshikazu TAI, Tomoaki SAIDA, Kazunari IMAKAWA, Satoshi SUZUKI
  • Patent number: 10695874
    Abstract: 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: Grant
    Filed: December 13, 2018
    Date of Patent: June 30, 2020
    Assignee: NISSHIN STEEL CO., LTD.
    Inventors: Yoshiaki Hori, Kazunari Imakawa
  • Patent number: 10670350
    Abstract: 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: Grant
    Filed: December 13, 2018
    Date of Patent: June 2, 2020
    Assignee: NIPPON STEEL NISSHIN CO., LTD.
    Inventors: Yoshiaki Hori, Kazunari Imakawa
  • Patent number: 10570979
    Abstract: 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: Grant
    Filed: August 10, 2016
    Date of Patent: February 25, 2020
    Assignee: NIPPON STEEL NISSHIN CO., LTD.
    Inventors: Yoshiaki Hori, Kazunari Imakawa, Satoshi Suzuki
  • Publication number: 20190382874
    Abstract: 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: Application
    Filed: September 5, 2017
    Publication date: December 19, 2019
    Inventors: Yoshihiro OKA, Yoshitomo FUJIMURA, Kazunari IMAKAWA
  • Patent number: 10502507
    Abstract: 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: Grant
    Filed: February 18, 2015
    Date of Patent: December 10, 2019
    Assignee: NIPPON STEEL NISSHIN CO., LTD.
    Inventors: Atsushi Sugama, Manabu Oku, Yoshiaki Hori, Kazunari Imakawa
  • Publication number: 20190285367
    Abstract: 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: Application
    Filed: December 13, 2018
    Publication date: September 19, 2019
    Inventors: Yoshiaki HORI, Kazunari IMAKAWA
  • Publication number: 20190283189
    Abstract: 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: Application
    Filed: December 13, 2018
    Publication date: September 19, 2019
    Inventors: Yoshiaki HORI, Kazunari IMAKAWA
  • Publication number: 20190154177
    Abstract: 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: Application
    Filed: February 7, 2017
    Publication date: May 23, 2019
    Inventors: Seiji MITSUNAGA, Nobuhisa EBIHAMA, Yasuhiro EHARA, Kazunari IMAKAWA
  • Publication number: 20190093192
    Abstract: 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: Application
    Filed: January 24, 2017
    Publication date: March 28, 2019
    Applicant: NISSHIN STEEL CO., LTD.
    Inventors: Seiji MITSUNAGA, Nobuhisa EBIHAMA, Yasuhiro EHARA, Kazunari IMAKAWA
  • Publication number: 20190039165
    Abstract: 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: Application
    Filed: August 30, 2016
    Publication date: February 7, 2019
    Applicant: NISSHIN STEEL CO., LTD.
    Inventors: Yoshitomo FUJIMURA, Kazunari IMAKAWA, Osamu YAMAMOTO, Manabu OKU, Isamu HAYAKAWA, Hiroaki SHICHI, Yoshihide NARUSE
  • Patent number: 10161524
    Abstract: 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: Grant
    Filed: March 16, 2015
    Date of Patent: December 25, 2018
    Assignee: NISSHIN STEEL CO., LTD.
    Inventors: Naohito Kumano, Kazunari Imakawa, Manabu Oku
  • Publication number: 20180363089
    Abstract: 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: Application
    Filed: January 31, 2017
    Publication date: December 20, 2018
    Applicant: NISSHIN STEEL CO., LTD.
    Inventors: Yutaka YAKUSHIJIN, Akira HIRONAKA, Kazunari IMAKAWA
  • Publication number: 20180304433
    Abstract: 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: Application
    Filed: September 6, 2016
    Publication date: October 25, 2018
    Inventors: Tomoaki SAIDA, Yoshikazu TAI, Kazunari IMAKAWA
  • Publication number: 20180238410
    Abstract: 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: Application
    Filed: August 10, 2016
    Publication date: August 23, 2018
    Inventors: Yoshiaki HORI, Kazunari IMAKAWA, Satoshi SUZUKI