Patents by Inventor Keisuke Hitoshio

Keisuke Hitoshio 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: 9175360
    Abstract: There is provided a method for manufacturing a seamless steel pipe for line pipe, capable of improving the toughness of the seamless steel pipe for line pipe. A round billet having a chemical composition, by mass percent, of C: 0.02 to 0.15%, Si: at most 0.5%, and Mn: 0.5 to 2.5%, the balance being Fe and impurities, is heated. The heated round billet is piercing-rolled to produce a hollow shell. The hollow shell is elongated and rolled and sized to produce a seamless steel pipe. The seamless steel pipe is water cooled, and the water cooling is stopped when the temperature of the seamless steel pipe reaches at most 450° C. The water-cooled seamless steel pipe is quenched, and the quenched seamless steel pipe is tempered.
    Type: Grant
    Filed: July 2, 2012
    Date of Patent: November 3, 2015
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Keisuke Hitoshio, Kunio Kondo, Yuji Arai
  • Patent number: 8709174
    Abstract: A seamless steel pipe for line pipe having high strength and high toughness contains, by mass percent, C: 0.02 to 0.10%, Si: at most 0.5%, Mn: 0.5 to 2.0%, Al: 0.01 to 0.1%, P: at most 0.03%, S: at most 0.005%, Ca: at most 0.005%, and N: at most 0.007%, and further contains at least one selected from a group consisting of Ti: at most 0.008%, V: less than 0.06%, and Nb: at most 0.05%, the balance being Fe and impurities. A carbon equivalent Ceq defined by Formula (1) is at least 0.38, a content of Ti, V and Nb satisfies Formula (2), and the size of carbo-nitride containing at least one of Ti, V, Nb and Al is at most 200 nm, Ceq=C+Mn/6+(Cr+Mo+V)/5+(Ni+Cu)/15??(1) Ti+V+Nb<0.06??(2).
    Type: Grant
    Filed: September 11, 2012
    Date of Patent: April 29, 2014
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Yuji Arai, Keisuke Hitoshio
  • Publication number: 20130000790
    Abstract: A seamless steel pipe for line pipe having high strength and high toughness contains, by mass percent, C: 0.02 to 0.10%, Si: at most 0.5%, Mn: 0.5 to 2.0%, Al: 0.01 to 0.1%, P: at most 0.03%, S: at most 0.005%, Ca: at most 0.005%, and N: at most 0.007%, and further contains at least one selected from a group consisting of Ti: at most 0.008%, V: less than 0.06%, and Nb: at most 0.05%, the balance being Fe and impurities. A carbon equivalent Ceq defined by Formula (1) is at least 0.38, a content of Ti, V and Nb satisfies Formula (2), and the size of carbo-nitride containing at least one of Ti, V, Nb and Al is at most 200 nm, Ceq=C+Mn/6+(Cr+Mo+V)/5+(Ni+Cu)/15??(1) Ti+V+Nb<0.06??(2).
    Type: Application
    Filed: September 11, 2012
    Publication date: January 3, 2013
    Applicant: SUMITOMO METAL INDUSTRIES, LTD.
    Inventors: Yuji ARAI, Keisuke Hitoshio
  • Publication number: 20120267014
    Abstract: There is provided a method for manufacturing a seamless steel pipe for line pipe, capable of improving the toughness of the seamless steel pipe for line pipe. A round billet having a chemical composition, by mass percent, of C: 0.02 to 0.15%, Si: at most 0.5%, and Mn: 0.5 to 2.5%, the balance being Fe and impurities, is heated. The heated round billet is piercing-rolled to produce a hollow shell. The hollow shell is elongated and rolled and sized to produce a seamless steel pipe. The seamless steel pipe is water cooled, and the water cooling is stopped when the temperature of the seamless steel pipe reaches at most 450° C. The water-cooled seamless steel pipe is quenched, and the quenched seamless steel pipe is tempered.
    Type: Application
    Filed: July 2, 2012
    Publication date: October 25, 2012
    Applicant: Sumitomo Metal Industries, Ltd.
    Inventors: Keisuke Hitoshio, Kunio Kondo, Yuji Arai
  • Patent number: 8147623
    Abstract: To provide a steel pipe as a fuel injection pipe with high material strength, high internal pressure limit free from fatigue failure, prolonged fatigue life, and high reliability. A steel pipe as a fuel injection pipe of 500 N/mm2 or higher tensile strength comprising, by mass, C: 0.12 to 0.27%, Si: 0.05 to 0.40%, and Mn: 0.8 to 2.0%, and the balance being Fe and impurities, the contents of Ca, P, and S in the impurities being Ca: 0.001% or less, P: 0.02% or less, and S: 0.01% or less, respectively, characterized in that the maximum diameter of nonmetallic inclusions present in at least in a region extending from the inner surface of the steel pipe to a depth of 20 ?m is 20 ?m or less. Further, this steel pipe may contain, in place of a portion of Fe, at least one selected from among Cr: 1% or less, Mo: 1% or less, Ti: 0.04% or less, Nb: 0.04% or less, and V: 0.1% or less.
    Type: Grant
    Filed: October 2, 2008
    Date of Patent: April 3, 2012
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventors: Kikuo Asada, Osamu Endo, Katsunori Nagao, Keisuke Hitoshio
  • Patent number: 7846274
    Abstract: In order to manufacture a steel pipe for an air bag which can cope with increase in the pressure of gas blown into an air bag and decreases in the wall thickness of an accumulator, a steel having a composition, mass %, of: C: 0.05-0.20%, Si: 0.1-1.0%, Mn: 0.20-2.0%, P: at most 0.025%, S: at most 0.010%, Cr: 0.05-1.0%, Al: at most 0.10%, if necessary at least one of Mo: at most 0.50%, Ni: at most 1.5%, Cu: at most 0.5%, V: at most 0.2%, Ti: at most 0.1%, Nb: at most 0.1%, and B: at most 0.005%, and also if necessary, at least one of Ca: at most 0.01%, Mg: at most 0.01%, and REM (rare earth elements): at most 0.01%, and a remainder of Fe and impurities is used to produce a steel pipe, and the pipe is then subjected to cold working to predetermined dimensions, then to heating to a temperature of at least the Ac1 transformation temperature followed by quenching, and then to tempering at a temperature no higher than the Ac1 transformation temperature.
    Type: Grant
    Filed: September 24, 2004
    Date of Patent: December 7, 2010
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventors: Kunio Kondo, Miyuki Yamamoto, Takashi Takano, Kenichi Beppu, Susumu Hirano, Keisuke Hitoshio, Hidetoshi Kurata
  • Patent number: 7566416
    Abstract: A steel pipe for an airbag inflator having a high strength of at least 900 MPa and preferably at least 1000 MPa in tensile strength along with a high toughness and exhibiting good resistance to bursting such that it has no propagation of cracks in a burst test at ?40° C. or below is manufactured by quenching a pipe of a steel comprising, in mass %, C: 0.05-0.20 %, Si: 0.1-1.0 %, P: at most 0.025 %, S: at most 0.010 %, Cr: 0.05-1.45 %, Al: at most 0.10 %, and one or both of Ti and Mn satisfying Ti?0.02% and 0.4%?Mn+40Ti?1.2% from a temperature of at least the Ac1 transformation point of the steel, tempering the pipe at a temperature lower than the Ac1 transformation point, applying cold working to it with a reduction of area of at most 65%, and subjecting it to stress relief annealing at a temperature lower than the Ac1 transformation point.
    Type: Grant
    Filed: October 28, 2005
    Date of Patent: July 28, 2009
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventors: Takashi Takano, Yuji Arai, Kunio Kondo, Keisuke Hitoshio
  • Publication number: 20090078341
    Abstract: To provide a steel pipe as a fuel injection pipe with high material strength, high internal pressure limit free from fatigue failure, prolonged fatigue life, and high reliability. A steel pipe as a fuel injection pipe of 500 N/mm2 or higher tensile strength comprising, by mass, C: 0.12 to 0.27%, Si: 0.05 to 0.40%, and Mn: 0.8 to 2.0%, and the balance being Fe and impurities, the contents of Ca, P, and S in the impurities being Ca: 0.001% or less, P: 0.02% or less, and S: 0.01% or less, respectively, characterized in that the maximum diameter of nonmetallic inclusions present in at least in a region extending from the inner surface of the steel pipe to a depth of 20 ?m is 20 ?m or less. Further, this steel pipe may contain, in place of a portion of Fe, at least one selected from among Cr: 1% or less, Mo: 1% or less, Ti: 0.04% or less, Nb: 0.04% or less, and V: 0.1% or less.
    Type: Application
    Filed: October 2, 2008
    Publication date: March 26, 2009
    Applicants: USUI KOKUSAI SANGYO KAISHA, LTD., SUMITOMO METAL INDUSTRIES, LTD.
    Inventors: KIKUO ASADA, Osamu Endo, Katsunori Nagao, Keisuke Hitoshio
  • Publication number: 20060124211
    Abstract: A steel pipe for an airbag inflator having a high strength of at least 900 MPa and preferably at least 1000 MPa in tensile strength along with a high toughness and exhibiting good resistance to bursting such that it has no propagation of cracks in a burst test at ?40° C. or below is manufactured by quenching a pipe of a steel comprising, in mass %, C: 0.05-0.20 %, Si: 0.1-1.0 %, P: at most 0.025 %, S: at most 0.010 %, Cr: 0.05-1.45 %, Al: at most 0.10 %, and one or both of Ti and Mn satisfying Ti<0.02% and 0.4%?Mn+40Ti?1.2% from a temperature of at least the Ac1 transformation point of the steel, tempering the pipe at a temperature lower than the Ac1 transformation point, applying cold working to it with a reduction of area of at most 65%, and subjecting it to stress relief annealing at a temperature lower than the Ac1 transformation point.
    Type: Application
    Filed: October 28, 2005
    Publication date: June 15, 2006
    Inventors: Takashi Takano, Yuji Arai, Kunio Kondo, Keisuke Hitoshio
  • Publication number: 20050266927
    Abstract: A steel tube hot-finished by the Mannesmann tube-making method is subjected to a simple grinding process for the inner surface, and thereafter to a cold drawing, so that the depth d of the concave portion in the concavo-convex profile forming the inner surface of the steel tube, the surface roughness Ra and the width w of the entrance in the concave portion are specified, or similarly the depth d of the concave portion in the concavo-convex profile, the Vickers hardness Hv of the inner surface layer and the width w of the entrance in the concave portion are specified, hollow parts for a drive shaft, which have an excellent fatigue strength and which is optimal to reduce the weight of a car body, can be produced. Accordingly, the application of the manufacturing method according to the present invention allows drive shafts for automobiles to be efficiently produced in a reduced manufacturing cost, thereby providing a significant advantage in the industry.
    Type: Application
    Filed: July 29, 2005
    Publication date: December 1, 2005
    Inventors: Kouichi Kuroda, Tatsuya Okui, Keisuke Hitoshio
  • Patent number: 6878219
    Abstract: In order to manufacture a steel pipe for an air bag which can cope with increase in the pressure of gas blown into an air bag and decreases in the wall thickness of an accumulator, a steel having a composition, mass %, of: C: 0.05-0.20%, Si: 0.1-1.0%, Mn: 0.20-2.0%, P: at most 0.025%, S: at most 0.010%, Cr: 0.05-1.0%, Al: at most 0.10%, if necessary at least one of Mo: at most 0.50%, Ni: at most 1.5%, Cu: at most 0.5%, V: at most 0.2%, Ti: at most 0.1%, Nb: at most 0.1%, and B: at most 0.005%, and also if necessary, at least one of Ca: at most 0.01%, Mg: at most 0.01%, and REM (rare earth elements): at most 0.01%, and a remainder of Fe and impurities is used to produce a steel pipe, and the pipe is then subjected to cold working to predetermined dimensions, then to heating to a temperature of at least the Ac1 transformation temperature followed by quenching, and then to tempering at a temperature no higher than the Ac1 transformation temperature.
    Type: Grant
    Filed: November 27, 2002
    Date of Patent: April 12, 2005
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventors: Kunio Kondo, Miyuki Yamamoto, Takashi Takano, Kenichi Beppu, Susumu Hirano, Keisuke Hitoshio, Hidetoshi Kurata
  • Publication number: 20050039826
    Abstract: In order to manufacture a steel pipe for an air bag which can cope with increase in the pressure of gas blown into an air bag and decreases in the wall thickness of an accumulator, a steel having a composition, mass %, of: C: 0.05-0.20%, Si: 0.1-1.0%, Mn: 0.20-2.0%, P: at most 0.025%, S: at most 0.010%, Cr: 0.05-1.0%, Al: at most 0.10%, if necessary at least one of Mo: at most 0.50%, Ni: at most 1.5%, Cu: at most 0.5%, V: at most 0.2%, Ti: at most 0.1%, Nb: at most 0.1%, and B: at most 0.005%, and also if necessary, at least one of Ca: at most 0.01%, Mg: at most 0.01%, and REM (rare earth elements): at most 0.01%, and a remainder of Fe and impurities is used to produce a steel pipe, and the pipe is then subjected to cold working to predetermined dimensions, then to heating to a temperature of at least the Ac1 transformation temperature followed by quenching, and then to tempering at a temperature no higher than the Ac1 transformation temperature.
    Type: Application
    Filed: September 24, 2004
    Publication date: February 24, 2005
    Inventors: Kunio Kondo, Miyuki Yamamoto, Takashi Takano, Kenichi Beppu, Susumu Hirano, Keisuke Hitoshio, Hidetoshi Kurata
  • Publication number: 20030155052
    Abstract: In order to manufacture a steel pipe for an air bag which can cope with increase in the pressure of gas blown into an air bag and decreases in the wall thickness of an accumulator, a steel having a composition, mass %, of: 1 C: 0.05-0.20%, Si: 0.1-1.0%, Mn: 0.20-2.0%, P: at most 0.025%, S: at most 0.010%, Cr: 0.05-1.0%, Al: at most 0.
    Type: Application
    Filed: November 27, 2002
    Publication date: August 21, 2003
    Inventors: Kunio Kondo, Miyuki Yamamoto, Takashi Takano, Kenichi Beppu, Susumu Hirano, Keisuke Hitoshio, Hidetoshi Kurata