Patents by Inventor Takashi Igawa

Takashi Igawa 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).

  • Patent number: 12134736
    Abstract: A method of producing a coal blend by blending plural brands of coal to produce a coal blend includes letting a surface tension of coal when inert material is assumed to be 100 vol % be ?100, and letting a surface tension of coal when reactive material is assumed to be 100 vol % be ?0, determining ?0 of coal; among brands of coal 1, 2, . . . i, . . . , and n to be blended in a coal blend, specifying coal i in which ?100 is outside of ?0; measuring TI of coal i; and determining a blending ratio of coal i such that w calculated by formula (1) is 20.4 mass % or less w=?(xi×TIi)??(1).
    Type: Grant
    Filed: December 25, 2020
    Date of Patent: November 5, 2024
    Assignee: JFE Steel Corporation
    Inventors: Daisuke Igawa, Takashi Matsui, Yusuke Dohi
  • Patent number: 12037546
    Abstract: A method of estimating a surface tension of coal includes subjecting a surface tension, a physical property value representing a coal rank, and a total inert content of each of different brands of coal to multiple regression analysis to determine in advance a regression equation including the surface tension of coal as an objective variable and the physical property value and the total inert content as explanatory variables; and measuring the physical property value and the total inert content of a coal of which the surface tension is to be estimated, and calculating the surface tension of the coal with the measured physical property value and the measured total inert content, and the regression equation.
    Type: Grant
    Filed: October 14, 2020
    Date of Patent: July 16, 2024
    Assignee: JFE Steel Corporation
    Inventors: Daisuke Igawa, Yusuke Dohi, Takashi Matsui
  • Publication number: 20110039069
    Abstract: The present invention provides a self-adhesive film which is a drawn polypropylene-based resin film comprising a laminated body containing an adhesive layer and a release layer which are provided on the surface of a base layer formed of a polypropylene-based resin, wherein an average surface roughness SRa of a surface of the above-described release layer is 0.200 ?m or less, an average surface layer roughness SRa of a surface of the self-adhesive layer of the film is 0.030 ?m or less, the contact area with the adherent, which is defined in the description, is 90% or more and 100% or less, and the film haze ranges from 1 to 40%. The self-adhesive film of the present invention is less likely to cause a blocking after the film is stored in a rolled state, and the processing suitability is excellent, and forming is less likely occur even when the film having been adhered to an adherend is processed at a high temperature, and further transparency is excellent.
    Type: Application
    Filed: March 27, 2009
    Publication date: February 17, 2011
    Applicant: TOYO BOSEKI KABUSHIKI KAISHA
    Inventors: Takashi Igawa, Shinichi Ohno, Akira Matsuda, Tohru Imai, Tadashi Nishi
  • Patent number: 7014719
    Abstract: An austenitic stainless steel comprising (C+½N) up to 0.060 mass %, Si up to 1.0 mass %, Mn up to 5 mass %, S up to 0.003 mass %, S/Mn ratio up to 0.003, 15–20 mass % Cr, 5–12 mass % Ni, Cu up to 5 mass %, 0–3.0 mass % Mo and the balance being Fe except inevitable impurities under the condition that a value Md30 (representing a ratio of a strain-induced martensite) defined by the under-mentioned formula is controlled within a range of ?60 to ?10. Hardness increase of the steel sheet after being cold-rolled is preferably 20% or more as Vickers hardness. A metallurgical structure of the steel sheet is preferably adjusted to grain size number of #8 to #11 in a finish annealed state. The steel sheet is blanked with high dimensional accuracy, and a die life is also prolonged. Md30=551?462(C+N)?9.2Si?29(Ni+Cu)?8.1Mn?13.7Cr?18.5Mo.
    Type: Grant
    Filed: August 23, 2002
    Date of Patent: March 21, 2006
    Assignee: Nisshin Steel Co., Ltd.
    Inventors: Satoshi Suzuki, Takashi Igawa, Hiroshi Fujimoto, Naoto Hiramatsu
  • Publication number: 20030099567
    Abstract: An austenitic stainless steel comprising (C+1/2N) up to 0.060 mass %, Si up to 1.0 mass %, Mn up to 5 mass %, S up to 0.003 mass %, S/Mn ratio up to 0.003, 15-20 mass % Cr, 5-12 mass % Ni, Cu up to 5 mass %, 0-3.0 mass % Mo and the balance being Fe except inevitable impurities under the condition that a value Md30 (representing a ratio of a strain-induced martensite) defined by the under-mentioned formula is controlled within a range of −60 to −10. Hardness increase of the steel sheet after being cold-rolled is preferably 20% or more as Vickers hardness. A metallurgical structure of the steel sheet is preferably adjusted to grain size number of #8 to #11 in a finish annealed state. The steel sheet is blanked with high dimensional accuracy, and a die life is also prolonged.
    Type: Application
    Filed: August 23, 2002
    Publication date: May 29, 2003
    Inventors: Satoshi Suzuki, Takashi Igawa, Hiroshi Fujimoto, Naoto Hiramatsu
  • Publication number: 20020015655
    Abstract: The newly proposed austenitic stainless steel has composition consisting of (C+½N) up to 0.060 mass %, Si up to 1.0 mass %, Mn up to 5 mass %, S up to 0.006 mass %, 15-20 mass % Cr, 5-12 mass % Ni, Cu up to 5 mass %, 0-3.0 mass % Mo and the balance being Fe except inevitable impurities under the condition that a value Md3O (representing a ratio of a strain-induced martensite) defined by the under-mentioned formula is controlled within a range of −60 to −10. Hardness increase of the steel sheet after being cold-rolled is preferably 20% or more as Vickers hardness. A metallurgical structure of the steel sheet is preferably adjusted to grain size number of #8 to #11 in a finish annealed state. The steel sheet is blanked with high dimensional accuracy, and a die life is also prolonged.
    Type: Application
    Filed: May 15, 2001
    Publication date: February 7, 2002
    Inventors: Satoshi Suzuki, Takashi Igawa, Hiroshi Fujimoto, Naoto Hiramatsu
  • Patent number: 5624504
    Abstract: A high strength and elongation stainless steel with a hardness of at least HV is formed of a duplex structure comprising 20% to 95% by volume of martensite having an average grain diameter of not more than 10 .mu.m, with the balance being essentially ferrite, the steel including, by weight, up to 0.10% C, up to 2.0% Si, up to 4.0% Mn, up to 0.040% P, up to 0.010% S, up to 4.0% Ni, from 10.0% to 20.0% Cr, up to 0.12% N, more than 0.0050% to 0.0300% B, up to 0.02% O and up to 4.0% Cu, and optionally contains up to 0.20% A1, up to 3% Mo, up to 0.20% REM, up to 0.20% Y, up to 0.10% Ca, and up to 0.10% Mg, with the balance being Fe and unavoidable impurities.
    Type: Grant
    Filed: July 11, 1995
    Date of Patent: April 29, 1997
    Assignee: Nisshin Steel Co., Ltd.
    Inventors: Katsuhisa Miyakusu, Yukio Oda, Takashi Igawa
  • Patent number: 5458156
    Abstract: A multifold pipe made by multiple rolling up and turning of a copper coated steel sheet into a multifold pipe, characterized in that said steel sheet is a cold rolled sheet of a super soft austenitic stainless steel comprising by weight: up to 0.05% of C, up to 1.0% of Si, up to 5.0% of Mn, from 9.0% to 15.0% of Ni, from 15.0% to 20.0% of Cr, up to 0.04% of N, up to 5.0% of Cu, the balance being Fe and unavoidable impurities, wherein the alloying elements are further adjusted so that both the two relations (1) and (2) noted below are satisfied:K=20.5+13.0.times.C+0.99.times.Si-1.1.times.Mn-Ni-0.4.times.Cu +0.4.times.Cr+117.1.times.N.ltoreq.19.5 (1)H=27.1+60.9.times.C+0.26.times.Si-Ni-0.79.times.Cu+0.68 .times.Cr+52.6.times.N.ltoreq.29.0 (2)The multifold pipe according to the invention is excellent in fluid tightness of its fused part and in corrosion resistance.
    Type: Grant
    Filed: October 29, 1993
    Date of Patent: October 17, 1995
    Assignees: Nisshin Steel Co., Ltd., Sanoh Kogyo Kabushiki Kaisha
    Inventors: Naoto Okubo, Yoshihiro Uematsu, Katsuhisa Miyakusu, Takashi Igawa, Yukio Oda, Yukito Nomura, Koichi Satake, Juichi Ozawa
  • Patent number: 5304259
    Abstract: A high strength chromium containing steel sheet having a tensile strength of at least 40 kgf/mm.sup.2, and excellent in corrosion resistance and workability, comprising, by weight, C:up to 0.030%, Si:up to 2.30%, Mn:up to 3.0%, P:more than 0.0005% and not more than 0.150%, S:up to 0.010%, Ni:up to 2.0%, Cu:more than 0% and not more than 2.0%, Cr:not less than 5.0% and less than 10.0%, N:up to 0.030%, V:not less than 0.01% and not more than 0.10%, and optionally at least one of 0.01 to 0.30% of Ti, 0.01 to 0.30% of Nb, 0.01 to 0.30% of Zr, 0.01 to 0.20% of Al and 0.0002 to 0.0200% of B, the amounts of Si, Mn, P, Ni and Cu being adjusted so that the relation:Si+Mn+10P+Ni+Cu>1.0% may be satisfied, the balance being iron and unavoidable impurities.
    Type: Grant
    Filed: April 19, 1993
    Date of Patent: April 19, 1994
    Assignee: Nisshin Steel Co., Ltd.
    Inventors: Katsuhisa Miyakusu, Masayuki Kinugasa, Yoshihiro Uematsu, Takashi Igawa, Hiroshi Fujimoto
  • Patent number: 5269856
    Abstract: A high strength steel belt having an excellent flatness and a duplex structure of austenite and martensite has been prepared by a process which comprises providing a cold rolled or cold rolled and annealed strip of a martensitic structure from low carbon martensitic stainless steel containing from 10 to 17% by weight of Cr and having a carbon content of not exceeding 0.15% by weight, connecting ends of the strip or ends of a plate cut from said strip to provide an endless belt, causing the endless belt to circularly move between rolls under tension and to pass through a heating furnace where the belt is heated to a temperature within a range from (As point of the steel+30.degree. C.) to Af point of the steel and not higher than 900.degree. C. so that a part of the martensitic phase may be changed to a reversed austenitic phase and a desired surface flatness may be obtained after cooling.
    Type: Grant
    Filed: November 13, 1992
    Date of Patent: December 14, 1993
    Assignee: Nisshin Steel Co., Ltd.
    Inventors: Takashi Igawa, Yoshihiro Uematsu, Toshihiko Takemoto
  • Patent number: 5265919
    Abstract: In order to provide a pipe joint of stainless steel including more than 10% of Cr which joint has excellent shape memory effect, the stainless steel comprises up to 0.10% of C, 3.0 to 6.0% of Si, 6.0 to 25.0% of Mn, up to 7.0% of Ni, more than 10.0 to 17.0% of Cr, 0.02 to 0.30% of N, 2.0 to 10.0% of Co, and optionally one or more selected from 0.05 to 0.8% of Nb, 0.05 to 0.8% of V, 0.05 to 0.8% of Zr, 0.05 to 0.8% of Ti, up to 2.0% of Mo and up to 2.0% of Cu and the alloying components are balanced so that no .delta.-ferritic phase may substantially appear in the annealed condition. Since the joint is treated so that it has such a shape memory effect that it will recover the memorized original shape with a smaller diameter when heated to an appropriate temperature, it can fasten a pipe or pipes merely by heating.
    Type: Grant
    Filed: December 24, 1991
    Date of Patent: November 30, 1993
    Assignee: Nisshin Steel Co., Ltd.
    Inventors: Toshihiko Takemoto, Masayuki Kinugasa, Teruo Tanaka, Takashi Igawa
  • Patent number: 5198041
    Abstract: A shape memory stainless steel containing more than 10% by weight of Cr excellent in resistance to stress corrosion cracking and having sufficient function as a shape memory alloy, which comprises, by weight, up to 0.10% of C, 3.0 to 6.0% of Si, 6.0 to 25.0% of Mn, up to 7.0% of Ni, more than 10.0% and not more than 17.0% of Cr, 0.02 to 0.3% of N, 2.0 to 10.0% of Co and more than 0.2% and not more than 3.5% of Cu, and at least one selected from up to 2.0% of Mo, 0.05 to 0.8% of Nb, 0.05 to 0.8% of V, 0.05 to 0.8% of Zr, 0.05 or 0.8% of Ti, the balance being Fe and unavoidable impurities, the alloying components being adjusted so that a D value is not less than-26.0, wherein the D value is defined by the following equation:D=Ni+0.30.times.Mn+56.8.times.C+19.0.times.N+0.73.times.Co+Cu -1.85.times.[Cr+1.6.times.Si+Mo+1.5.times.(Nb+V+Zr+Ti)].
    Type: Grant
    Filed: February 25, 1992
    Date of Patent: March 30, 1993
    Assignee: Nisshin Steel Co., Ltd.
    Inventors: Toshihiko Takemoto, Masayuki Kinugasa, Teruo Tanaka, Takashi Igawa
  • Patent number: 5178687
    Abstract: A chromium containing steel sheet excellent in corrosion resistance and workability, comprising, by weight, C:up to 0.030%, Si:up to 0.5%, Mn:up to 0.5%, P:up to 0.040%, S:up to 0.010%, Ni:up to 0.3%, Cu:up to 0.3%, Cr: not less than 5.0% and less than 11.0%, N:up to 0.030%, V:not less than 0.01% and not more than 0.10%, and optionally at least one of 0.01 to 0.30% of Ti, 0.01 to 0.30% of Nb, 0.01 to 0.30% of Zr, 0.01 to 0.20% of Al and 0.0002 to 0.0200% of B, the amounts of Si, Mn, P, Ni and Cu being adjusted so that the relation:Si+Mn+10P+Ni+Cu.ltoreq.1.0% may be satisfied, the balance being iron and unavoidable impurities.
    Type: Grant
    Filed: December 20, 1991
    Date of Patent: January 12, 1993
    Assignee: Nisshin Steel Co., Ltd.
    Inventors: Katsuhisa Miyakusu, Masayuki Kinugasa, Yoshihiro Uematsu, Takashi Igawa, Hiroshi Fujimoto
  • Patent number: 5171384
    Abstract: A high strength steel strip excellent in shape having a duplex structure of austenite and martensite has been prepared by a process which comprises providing a cold rolled or cold rolled and annealed strip of a martensitic structure from low carbon martensitic stainless steel containing from 10 to 17% by weight of Cr and having a carbon content of not exceeding 0.15% by weight, causing the strip to continuously pass through a continuous heat treatment furnace under tension where the strip is heated to temperatures within the range from (the As point of the steel+30.degree. C.) to the Af point of the steel and not higher than 900.degree. C.
    Type: Grant
    Filed: October 9, 1991
    Date of Patent: December 15, 1992
    Assignee: Nisshin Steel Co., Ltd.
    Inventors: Takashi Igawa, Yoshihiro Uematsu, Toshihiko Takemoto
  • Patent number: 4878955
    Abstract: A stainless steel which exhibits substantially martensitic structure at room temperature was heated at a temperature of 550.degree. to 675.degree. for 1 to 30 hours. Then a reverse-transformed austenite phase appeared and a stainless steel having high strength and high elongation and being free from weld softening was obtained.
    Type: Grant
    Filed: June 23, 1988
    Date of Patent: November 7, 1989
    Assignee: Nisshin Steel Company, Ltd.
    Inventors: Kazuo Hoshino, Takashi Igawa
  • Patent number: 4762575
    Abstract: A process for the production of an electrical steel sheet having the ideal (100) [001] cube texture of iron of iron alloy, comprising cold rolling a sheet of a single crystal or large grained crystals of iron or iron alloy, in which said single crystal is or a majority of said large grained crystals are oriented so that the pole of the {114} plane may form an angle not greater than 15.degree. with the normal direction of the plane of the sheet, and the <401> direction may form an angle of not greater than 15.degree. with a single direction in the plane of the sheet, in said single direction at a rolling reduction of at least 40%, and annealing the rolled sheet to form a primary recrystallization texture of fine grains of an average grain size of not larger than 5 mm under conditions preventing the occurrence of secondary recrystallization.
    Type: Grant
    Filed: June 13, 1986
    Date of Patent: August 9, 1988
    Assignee: Nisshin Steel Co., Ltd.
    Inventors: Akira Sakakura, Kazuo Hoshino, Yoshihiro Uematsu, Takashi Igawa, Hiroshi Fujimoto