Patents by Inventor Masahiko Arai

Masahiko Arai 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: 20120114496
    Abstract: It is an objective of the present invention to provide a precipitation-hardening martensitic stainless steel having well-balanced properties of high mechanical strength, high toughness and good corrosion resistance properties. There is provided a precipitation-hardening martensitic stainless steel comprising: 0.10 mass % or less of C; 13.0 to 15.0 mass % of Cr; 7.0 to 10.0 mass % of Ni; 2.0 to 3.0 mass % of Mo; 0.5 to 2.5 mass % of Ti; 0.5 to 2.5 mass % of Al; 0.5 mass % or less of Si; 0.1 to 1.0 mass % of Mn; and the balance including Fe and incidental impurities, in which the mass % content of the Ti (represented by [Ti content]), the mass % content of the Al (represented by [Al content]) and the mass % content of the C (represented by [C content]) satisfy relationships of “0.5?[Ti content]?2.5” and “0.5?[Al content]+2[C content]?2.7”.
    Type: Application
    Filed: November 9, 2011
    Publication date: May 10, 2012
    Inventors: Shinji Oikawa, Hideo Yoda, Masahiko Arai, Hiroyuki Doi
  • Publication number: 20120116073
    Abstract: A compound having the following formula (II) or its pharmacologically acceptable salt is used as a P2X4 receptor antagonist: in which R11 represents hydrogen or an alkyl group having 1-8 carbon atoms; R21 represents an alkyl group having 1-8 carbon atoms, an alkoxy group having 1-8 carbon atoms, an alkyl group having 1-8 carbon atoms and having 1-3 halogen substituents, or hydroxyl; and R31 is hydrogen or a halogen atom.
    Type: Application
    Filed: January 20, 2012
    Publication date: May 10, 2012
    Applicant: NIPPON CHEMIPHAR COL, LTD.
    Inventors: Shogo SAKUMA, Tsuyoshi Endo, Toshiyasu Imai, Noriko Kanakubo, Masahiko Arai, Toshihiro Takahashi, Kenji Hirate, Takako Hirate, Tomio Yamakawa, Makoto Tsuda, Kazuhide Inoue
  • Publication number: 20110255988
    Abstract: A precipitation hardenable martensitic stainless steel excellent in the stability of martensite, having the high strength, high toughness and high corrosion resistance is provided. The precipitation hardenable martensitic stainless steel contains at a mass rate, C: 0.05-0.10%, Cr: 12.0-13.0%, Ni: 6.0-7.0%, Mo: 1.0-2.0%, Si: 0.01-0.05%, Mn: 0.06-1.0%, Nb: 0.3-0.5%, V: 0.3-0.5%, Ti: 1.5-2.5%, Al: 1.0-2.3%, and the remainder consisting of Fe and an unavoidable impurity.
    Type: Application
    Filed: April 14, 2011
    Publication date: October 20, 2011
    Inventors: Shinji OIKAWA, Hideo Yoda, Masahiko Arai, Hiroyuki Doi
  • Patent number: 8025746
    Abstract: A casing is formed from an alloy which contains, by mass, 0.08-0.20% C, 0.05-0.45% Si, 0.10-0.30% Mn, 0.80-1.40% Ni, 1.00-1.40% Cr, 1.20-1.60% Mo, 0.10-0.30% V, 0.06-0.10% Ti, 0.0005-0.0010% B, not more than 0.01% P, not more than 0.01% S, and not more than 0.005% Al, the balance being Fe and unavoidable impurity elements. The casing has excellent high-temperature strength, high toughness and excellent weldability, and is applicable to casings used in high-temperature high-pressure steam environments.
    Type: Grant
    Filed: March 22, 2007
    Date of Patent: September 27, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Hirotsugu Kawanaka, Masahiko Arai, Tateki Nakamura
  • Publication number: 20110126540
    Abstract: A high-strength heat resisting cast steel which has high creep rupture strength at temperatures of 620° C. or above, high toughness, and good weldability. A method of producing the steel, a steam turbine casing, a main steam valve casing, and a steam control valve casing, each casing being made of that steel, as well as a steam turbine power plant using those components are also provided. The high-strength heat resisting cast steel contains 0.06-0.16% by mass of C, 0.1-1% of Si, 0.1-1% of Mn, 8-12% of Cr, 0.1-1.0% of Ni, 0.7% or less of Mo, 1.9-3.0% of W, 0.05-0.3% of V, 0.01-0.15% of one or more of Nb, Ta and Zr in total, 0.1-2% of Co, 0.01-0.08% of N, and 0.0005-0.01% of B, the balance being Fe and unavoidable impurities.
    Type: Application
    Filed: February 7, 2011
    Publication date: June 2, 2011
    Applicant: HITACHI, LTD.
    Inventors: Masahiko ARAI, Hirotsugu KAWANAKA, Hideo YODA
  • Publication number: 20110092703
    Abstract: A P2X4 receptor antagonist is a compound represented by the formula (I) or a pharmacologically acceptable salt thereof, which is used as a preventive or therapeutic agent for neuropathic pains: Wherein B is aryl or the like that can have a substituent; Y is C1-5 alkylene that can have a double bond; Z is O, S or the like; each of R1, R2 and R3 independently is hydrogen, C1-8 alkyl or the like; R4 is hydrogen, C1-8 alkyl or the like; each of P and Q independently is hydrogen, halogen, C1-8 alkyl or the like; W is C1-8 alkyl or the like; and each of n and m independently is 1 or 2.
    Type: Application
    Filed: August 8, 2008
    Publication date: April 21, 2011
    Applicant: NIPPON CHEMIPHAR CO., LTD.
    Inventors: Shogo Sakuma, Tsuyoshi Endo, Noriko Kanakubo, Masahiko Arai, Toshihiro Takahashi, Toshiyasu Imai, Kumiko Taguchi, Eriko Nakata, Nobutaka Mochiduki, Masatoshi Ushioda, Makoto Tsuda, Kazuhide Inoue
  • Publication number: 20100329849
    Abstract: A turbine rotor which is easy to manufacture and has a high tolerable temperature is provided. A highly efficient steam turbine power plant is also provided. The turbine rotor is configured from a rotor shaft, an inner rotor disc constructed integrally with the rotor shaft, and an outer rotor disc which is welded to the inner rotor disc via a weld metal part and has a structure for fixing a turbine blade. The outer rotor disc preferably has a cooling hole which extends in an axial direction to penetrate the outer rotor disc over the thickness of the outer rotor disc.
    Type: Application
    Filed: June 23, 2010
    Publication date: December 30, 2010
    Inventors: Eiji NISHIOKA, Masahiko Arai, Hiroyuki Doi
  • Publication number: 20100256123
    Abstract: A compound having the following formula (II) or its pharmacologically acceptable salt is used as a P2X4 receptor antagonist: in which R11 represents hydrogen or an alkyl group having 1-8 carbon atoms; R21 represents an alkyl group having 1-8 carbon atoms, an alkoxy group having 1-8 carbon atoms, an alkyl group having 1-8 carbon atoms and having 1-3 halogen substituents, or hydroxyl; and R31 is hydrogen or a halogen atom.
    Type: Application
    Filed: August 24, 2007
    Publication date: October 7, 2010
    Applicant: NIPPON CHEMIPHAR CO., LTD.
    Inventors: Shogo Sakuma, Tsuyoshi Endo, Toshiyasu Imai, Noriko Kanakubo, Masahiko Arai, Toshihiro Takahashi, Tomio Yamakawa, Makoto Tsuda, Kazuhide Inoue, Kenji Hirate, Takako Hirate
  • Publication number: 20100236333
    Abstract: The present invention is intended to provide a method for assessing remaining lifespan of a bolt with higher precision than conventional methods, which can be applied to a bolt comprising a high alloy with fewer tissue changes caused by creep damage. The present invention provides a method for assessing the remaining lifespan of a bolt used at high temperatures, including: carrying out a creep test for a bolt material that constitutes a bolt to be assessed and determining a life-time and a life-elongation rate; determining a time-temperature parameter based on the life-time and the creep test temperature; creating a lifespan-assessment diagram by plotting the time-temperature parameter with respect to the life-elongation rate; measuring a elongation rate between before and after the use of the bolt to be assessed; and assessing the remaining lifespan of the bolt with the use of the elongation rate between before and after the use of the bolt to be assessed and the lifespan-assessment diagram.
    Type: Application
    Filed: February 18, 2010
    Publication date: September 23, 2010
    Inventors: Masahiko ARAI, Shinichi KOBAYASHI, Hiroyuki DOI, Hiroaki CHIBA, Takashi HANEISHI
  • Publication number: 20100122754
    Abstract: A high-strength martensite heat resisting steel which has long-time creep rupture strength required for steam temperature condition of 600-630° C. and toughness at room temperature, and which is suitable for use as a material of a steam turbine rotor shaft and as large-sized forged steel with an improvement of hot forgeability. A method of producing the steel and applications of the steel are also provided. The high-strength martensite heat resisting steel contains 0.05-0.20% by mass of C, 0.1% or less of Si, 0.05-0.6% of Mn, 0.1-0.6% of Ni, 9.0-12.0% of Cr, 0.20-0.65% of Mo, 2.0-3.0% of W, 0.1-0.3% of V, 2.0% or less of Co, 0.02-0.20% of Nb, 0.015% or less of B, 0.01-0.10% of N, and 0.015% or less of Al, (W/Mo) being 4.0-10.0.
    Type: Application
    Filed: September 28, 2006
    Publication date: May 20, 2010
    Inventors: Hirotsugu Kawanaka, Masahiko Arai, Hideo Yoda
  • Publication number: 20100028155
    Abstract: An object of the present invention is to provide a turbine rotor with high reliability of strength. The turbine rotor includes two rotors which are connected at the butted portions of the rotors via a weld without forming penetration beads. Specifically, the turbine rotor includes a rotor for low pressure, a rotor for high pressure, and a center hole formed at a center portion of the turbine rotor. The rotors for low pressure and for high pressure are integrated together into a steam turbine rotor by welding respective ends of the rotors to each other. The respective ends of the rotors are in contact with each other via at least two contact faces in a radial direction and an axial direction of the turbine rotor. At least parts of the respective ends are welded together.
    Type: Application
    Filed: July 27, 2009
    Publication date: February 4, 2010
    Inventors: Eiji Nishioka, Masahiko Arai, Ryusuke Hiruta, Hiroyuki Doi
  • Publication number: 20090311103
    Abstract: A steam turbine rotor shaft and a method of manufacturing the same are provided wherein the sliding characteristics of a journal are improved, and the journal is free from welding cracks and does not need a post heat treatment. The low alloy steel coating layer having a better sliding characteristics than 9 to 13% Cr heat resisting steel and a area rate of defects including pores and oxides in a range of 3 to 15% is formed by a high velocity flame spray coating method on a sliding surface of the journal.
    Type: Application
    Filed: June 9, 2006
    Publication date: December 17, 2009
    Inventors: Hideyuki Arikawa, Akira Mebata, Masahiko Arai, Yoshitaka Kojima, Hajime Toriya
  • Patent number: 7632066
    Abstract: A pipe for a steam turbine is formed of a centrifugal casting material to achieve resistance against higher temperatures and improve reliability of the pipe by employing, as a pipe material, a centrifugal casting material normalized to contain uniform and finer crystal grains. The centrifugal casting material is made of steel having a columnar structure in the radial direction with the crystal grain size number of 5 or more in a plane perpendicular to the radial direction. The steel includes 0.05-0.5% by mass C, not more than 1.0% Si, 0.05-1.5% Mn, 0.01-2.5% Ni, 8.0-13.0% Cr, 0.05-2.5% Mo, not more than 3.0% W, 0.05-0.35% V, 0.01-0.5% Nb, not more than 5% Co, 0.01-0.1% N, not more than 0.03% B, and not more than 0.05% Al.
    Type: Grant
    Filed: July 6, 2006
    Date of Patent: December 15, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Masahiko Arai, Hirotsugu Kawanaka, Hiroyuki Doi, Kenichi Murata, Hajime Toriya
  • Patent number: 7540711
    Abstract: The invention provides a heat resisting steel having superior high-temperature strength and notch rupture strength, a rotor shaft using the heat resisting steel, a steam turbine using the rotor shaft, and a power plant using the steam turbine. The heat resisting steel is made of a Cr—Mo—V low-alloy steel containing 0.15-0.40% by weight of C, not more than 0.5% of Si, 0.05-0.50% of Mn, 0.5-1.5% of Ni, 0.8-1.5% of Cr, 0.8-1.8% of Mo and 0.05-0.35% of V, and having a (Ni/Mn) ratio of 3.0-10.0.
    Type: Grant
    Filed: July 5, 2005
    Date of Patent: June 2, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Masahiko Arai, Hirotsugu Kawanaka, Kennichi Murata, Hideo Yoda
  • Publication number: 20090068052
    Abstract: The invention is of a heat resisting martensitic steel comprising, by weight, 0.05 to 0.30% C, not more than 0.50% Si, not more than 0.60% Mn, 8.0 to 13.0% Cr, 0.5 to 3.0% Ni, 1.0 to 3.0% Mo, 0.1 to 1.5% W, 0.5 to 4% Co, 0.05 to 0.35% V, 0.02 to 0.30% in total of one or two elements selected from the group consisting of Nb and Ta, and 0.02 to 0.10% N, wherein a value of the square of a difference between the Ni amount and the Co amount, and the Ni amount are not more than values determined by a straight line drawn on a point A (1.0, 2.7%) and a point B (2.5, 1.0%) in the orthogonal coordinates shown in the attached drawing of FIG. 2 which represents a relationship between the above square value and the Ni amount, and an amount ratio of Mo/(Mo+0.5W) is not less than 0.5. The heat resisting steel is suitably used in various components of a gas turbine.
    Type: Application
    Filed: May 21, 2008
    Publication date: March 12, 2009
    Applicant: HITACHI, LTD.
    Inventors: Masahiko Arai, Hirotsugu Kawanaka, Hiroyuki Doi, Isao Takehara, Hidetoshi Kuroki
  • Publication number: 20070224041
    Abstract: A casing is formed from an alloy which contains, by mass, 0.08-0.20% C, 0.05-0.45% Si, 0.10-0.30% Mn, 0.80-1.40% Ni, 1.00-1.40% Cr, 1.20-1.60% Mo, 0.10-0.30% V, 0.06-0.10% Ti, 0.0005-0.0010% B, not more than 0.01% P, not more than 0.01% S, and not more than 0.005% Al, the balance being Fe and unavoidable impurity elements. The casing has excellent high-temperature strength, high toughness and excellent weldability, and is applicable to casings used in high-temperature high-pressure steam environments.
    Type: Application
    Filed: March 22, 2007
    Publication date: September 27, 2007
    Inventors: Hirotsugu Kawanaka, Masahiko Arai, Tateki Nakamura
  • Publication number: 20070071599
    Abstract: A high-strength heat resisting cast steel which has high creep rupture strength at temperatures of 620° C. or above, high toughness, and good weldability. A method of producing the steel, a steam turbine casing, a main steam valve casing, and a steam control valve casing, each casing being made of that steel, as well as a steam turbine power plant using those components are also provided. The high-strength heat resisting cast steel contains 0.06-0.16% by mass of C, 0.1-1% of Si, 0.1-1% of Mn, 8-12% of Cr, 0.1-1.0% of Ni, 0.7% or less of Mo, 1.9-3.0% of W, 0.05-0.3% of V, 0.01-0.15% of one or more of Nb, Ta and Zr in total, 0.1-2% of Co, 0.01-0.08% of N, and 0.0005-0.01% of B, the balance being Fe and unavoidable impurities.
    Type: Application
    Filed: September 28, 2006
    Publication date: March 29, 2007
    Inventors: Masahiko Arai, Hirotsugu Kawanaka, Hideo Yoda
  • Publication number: 20070014671
    Abstract: A pipe for a steam turbine is formed of a centrifugal casting material to achieve resistance against higher temperatures and improve reliability of the pipe by employing, as a pipe material, a centrifugal casting material normalized to contain uniform and finer crystal grains. The centrifugal casting material is made of steel having a columnar structure in the radial direction with the crystal grain size number of 5 or more in a plane perpendicular to the radial direction. The steel includes 0.05-0.5% by mass C, not more than 1.0% Si, 0.05-1.5% Mn, 0.01-2.5% Ni, 8.0-13.0% Cr, 0.05-2.5% Mo, not more than 3.0% W, 0.05-0.35% V, 0.01-0.5% Nb, not more than 5% Co, 0.01-0.1% N, not more than 0.03% B, and not more than 0.05% Al.
    Type: Application
    Filed: July 6, 2006
    Publication date: January 18, 2007
    Inventors: Masahiko Arai, Hirotsugu Kawanaka, Hiroyuki Doi, Kenichi Murata, Hajime Toriya
  • Publication number: 20060216145
    Abstract: The invention provides a heat resisting steel having superior high-temperature strength and notch rupture strength, a rotor shaft using the heat resisting steel, a steam turbine using the rotor shaft, and a power plant using the steam turbine. The heat resisting steel is made of a Cr—Mo—V low-alloy steel containing 0.15-0.40% by weight of C, not more than 0.5% of Si, 0.05-0.50% of Mn, 0.5-1.5% of Ni, 0.8-1.5% of Cr, 0.8-1.8% of Mo and 0.05-0.35% of V, and having a (Ni/Mn) ratio of 3.0-10.0.
    Type: Application
    Filed: July 5, 2005
    Publication date: September 28, 2006
    Inventors: Masahiko Arai, Hirotsugu Kawanaka, Kennichi Murata, Hideo Yoda
  • Publication number: 20050074356
    Abstract: The invention is of a heat resisting martensitic steel comprising, by weight, 0.05 to 0.30% C, not more than 0.50% Si, not more than 0.60% Mn, 8.0 to 13.0% Cr, 0.5 to 3.0% Ni, 1.0 to 3.0% Mo, 0.1 to 1.5% W, 0.5 to 4% Co, 0.05 to 0.35% V, 0.02 to 0.30% in total of one or two elements selected from the group consisting of Nb and Ta, and 0.02 to 0.10% N, wherein a value of the square of a difference between the Ni amount and the Co amount, and the Ni amount are not more than values determined by a straight line drawn on a point A (1.0, 2.7%) and a point B (2.5, 1.0%) in the orthogonal coordinates shown in the attached drawing of FIG. 2 which represents a relationship between the above square value and the Ni amount, and an amount ratio of Mo/(Mo+0.5 W) is not less than 0.5. The heat resisting steel is suitably used in various components of a gas turbine.
    Type: Application
    Filed: January 16, 2004
    Publication date: April 7, 2005
    Inventors: Masahiko Arai, Hirotsugu Kawanaka, Hiroyuki Doi, Isao Takehara, Hidetoshi Kuroki