Patents by Inventor Hiroyuki Doi

Hiroyuki Doi 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: 8685316
    Abstract: A Ni-based heat resistant alloy has a composition of, by mass percent, carbon: 0.001 to 0.1%, chromium: 16 to 22%, aluminum: 0.5 to 1.5%, molybdenum: 0.1 to 2.0%, tungsten: 0.1 to 6.0%, niobium: 3.5 to 5.5%, titanium: 0.8 to 3.0%, iron: 16 to 20%, and the balance being nickel and inevitable impurities. A parameter Ps indicating a segregation tendency is in a range of Ps??3.5. The parameter Ps is represented by Formula (1). Ps=1.05×Al content+0.6×Ti content?0.8×Nb content?0.
    Type: Grant
    Filed: November 1, 2011
    Date of Patent: April 1, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Jun Sato, Shinya Imano, Hiroyuki Doi
  • Publication number: 20140064939
    Abstract: A metal sealing material used in a sealing device which can reduce a gap between a stator and a rotor of a turbine. The metal sealing material used in a sealing device for a stator and a rotor of a turbine includes a surface layer and a lower layer composed of a porous metal layer, wherein the porosity of the surface layer is smaller than the porosity of the lower layer; the porosity of the surface layer is 60 to 65% and the porosity of the lower layer is 67 to 75% or less; and the porous metal layer has a thickness of 0.3 to 3.0 mm and may include, as a main component, an MCrAlY alloy where M is either one of Ni and Co or both thereof, and h-BN as a solid lubricant.
    Type: Application
    Filed: August 28, 2013
    Publication date: March 6, 2014
    Applicant: HITACHI, LTD.
    Inventors: Yoshitaka KOJIMA, Hideyuki ARIKAWA, Akira MEBATA, Hiroyuki DOI, Hajime TORIYA, Kenjiro NARITA
  • Publication number: 20140020768
    Abstract: A grease pump unit has a metering valve 37 and a grease supplying device 50 in which a suction tube 16 on a pump device 11 extends through a follower plate 19 in a grease can 100, grease in the grease can 100 being sucked through the suction tube 16 and discharged through a discharge port 17 by activation of the pump device 11. Provided are a bubble dividing device 32 which supplies the grease discharged through the discharge port 17 through an supply pipe 24 to micronize bubbles in the grease and which supplies the grease through a supply pipe 36 to the metering valve 37, and a return pipe 47 which returns a portion of the grease not discharged through the metering valve 37 into the grease can 100 via the follower plate 19.
    Type: Application
    Filed: January 17, 2012
    Publication date: January 23, 2014
    Applicants: KOGANEI CORPORATION, IHI COMPRESSOR AND MACHINERY CO., LTD
    Inventors: Hiroyuki Doi, Hirokazu Tanaka
  • Patent number: 8596982
    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: Grant
    Filed: June 23, 2010
    Date of Patent: December 3, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Eiji Nishioka, Masahiko Arai, Hiroyuki Doi
  • Publication number: 20130263796
    Abstract: A high-temperature piping product is configured from a plurality of primary pipe members and a welding material. The primary pipe members are each made from an Ni-based forged alloy containing: Ni, Al, and at least one of Mo and W. The total content of the Mo and the W being 3-8 mass %. The Ni-based forged alloy exhibiting a ??-phase dissolution temperature of from 920 to 970° C., and the ?? phase being precipitated in 30 volume % or more in a temperature range of from 700 to 800° C. The welding material is made from an Ni-based cast alloy having a cast structure formed by welding. The Ni-based cast alloy containing: Ni, Al, and at least one of Mo and W, the total content of the Mo and the W being 9-15 mass %, the Ni-based cast alloy exhibiting a ??-phase dissolution temperature of from 850 to 900° C.
    Type: Application
    Filed: April 8, 2013
    Publication date: October 10, 2013
    Applicant: Hitachi, Ltd.
    Inventors: Shinya IMANO, Hiroyuki DOI, Jun SATO
  • Publication number: 20130255442
    Abstract: A Ni-based alloy for a welding material including, by mass, 0.001 to 0.1% of C, 18 to 25% of Co, 16 to 20% of Cr, 2.5 to 3.5% of Al, 9.0 to 15.0% of Mo+W, 0.001 to 0.03% of B and the balance being Ni and inevitable impurities.
    Type: Application
    Filed: February 19, 2013
    Publication date: October 3, 2013
    Applicant: HITACHI, LTD.
    Inventors: Shinya IMANO, Hiroyuki DOI, Jun SATO
  • Patent number: 8524149
    Abstract: A nickel base alloy includes: by mass, 0.001 to 0.1% of carbon; 12 to 23% of chromium; 15 to 25% of cobalt; 3.5 to 5.0% of aluminum; 4 to 12% of molybdenum; 0.1 to 7.0% of tungsten; and a total amount of Ti, Ta and Nb being not more than 0.5%. A parameter Ps represented by a formula (1) shown below is 0.6 to 1.6, Ps=?7×[C]?0.1×[Mo]+0.5×[Al]??(1) where [C] indicates an amount of carbon; [Mo] indicates an amount of molybdenum; and [Al] indicates an amount of aluminum, by mass percent.
    Type: Grant
    Filed: March 22, 2010
    Date of Patent: September 3, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Jun Sato, Shinya Imano, Hiroyuki Doi
  • Patent number: 8512488
    Abstract: An Ni—Fe based superalloy forging material including 30 to 40 wt % of Fe, 14 to 16 wt % of Cr, 1.2 to 1.7 wt % of Ti, 1.1 to 1.5 wt % of Al, 1.9 to 2.2 wt % of Nb, 0.05 wt % or less of C and the remainder of Ni and inevitable impurities is solution-treated and aged, and thereby ?? phase (Ni3Al) having an initial mean particle size of about 50 to about 100 nm is precipitated. This superalloy is excellent in high-temperature strength and high-temperature ductility and can produce a large forged product of 10 ton or more. Therefore, this material is suitable for use as the material of a steam turbine rotor having a main steam temperature of 650° C. or more.
    Type: Grant
    Filed: August 10, 2007
    Date of Patent: August 20, 2013
    Assignees: Hitachi, Ltd., The Japan Steel Works, Ltd.
    Inventors: Shinya Imano, Hirotsugu Kawanaka, Hiroyuki Doi, Tatsuya Takahashi, Tsukasa Azuma, Koji Kajikawa
  • Patent number: 8500397
    Abstract: A seal structure for a steam turbine is provided, which is capable of suppressing transfer of heat generated by a friction between a rotating portion and a fixed portion to the rotating portion and of suppressing an increase in the temperature of the rotating portion. A labyrinth seal device serves to suppress the amount of steam leaking from a clearance present between each stator blade (fixed portion) of the steam turbine and a rotor (rotating portion). The seal structure for the steam turbine is formed to ensure that permeable spacers made of a permeable metal are provided on the rotor and a seal stationary body and face respective seal fins provided in the labyrinth seal device.
    Type: Grant
    Filed: February 14, 2012
    Date of Patent: August 6, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Kenjiro Narita, Haruyuki Yamazaki, Hiroyuki Doi, Kei Kobayashi, Hajime Toriya
  • Patent number: 8444778
    Abstract: Disclosed is a low-thermal-expansion Ni-based super-heat-resistant alloy for a boiler, which has excellent high-temperature strength. The alloy can be welded without the need of carrying out any aging treatment. The alloy has a Vickers hardness value of 240 or less. The alloy comprises (by mass) C in an amount of 0.2% or less, Si in an amount of 0.5% or less, Mn in an amount of 0.5% or less, Cr in an amount of 10 to 24%, one or both of Mo and W in such an amount satisfying the following formula: Mo+0.5 W=5 to 17%, Al in an amount of 0.5 to 2.0%, Ti in an amount of 1.0 to 3.0%, Fe in an amount of 10% or less, and one or both of B and Zr in an amount of 0.02% or less (excluding 0%) for B and in an amount of 0.2% or less (excluding 0%) for Zr, with the remainder being 48 to 78% of Ni and unavoidable impurities.
    Type: Grant
    Filed: August 29, 2008
    Date of Patent: May 21, 2013
    Assignees: Hitachi Metals, Ltd., Babcock-Hitachi Kabushiki Kaisha, Hitachi, Ltd.
    Inventors: Toshihiro Uehara, Takehiro Ohno, Akihiro Toji, Takashi Sato, Gang Bao, Shinya Imano, Hiroyuki Doi
  • Publication number: 20120321478
    Abstract: This invention provides a precipitate hardening stainless steel having excellent structure stability, strength, toughness, and corrosion resistance, which requires no sub-zero treating and thus is excellent in terms of productivity, and a long blade for a steam turbine using the same. The following are provided: a precipitate hardening stainless steel, which comprises C at 0.05 mass % or less, N at 0.05 mass % or less, Cr at 10.0 mass % to 14.0 mass %, Ni at 8.5 mass % to 11.5 mass %, Mo at 0.5 mass % to 3.0 mass %, Ti at 1.5 mass % to 2.0 mass %, Al at 0.25 mass % to 1.00 mass %, Si at 0.5 mass % or less, and Mn at 1.0 mass % or less, and the balance is composed of Fe and inevitable impurities; and a long blade for a steam turbine composed of the precipitate hardening stainless steel.
    Type: Application
    Filed: June 13, 2012
    Publication date: December 20, 2012
    Inventors: Shinji OIKAWA, Hideo YODA, Masahiko ARAI, Hiroyuki DOI
  • Publication number: 20120308772
    Abstract: An object is to provide a steam turbine member having excellent oxidation resistance at low cost without using an alloy coating such as a thermally sprayed or sintered body. The steam turbine member includes a substrate made of stainless steel containing Fe as a main component, 8 to 15 wt % of Cr, and 0.1 to 1.0 wt % of Mn. The steam turbine member has, on a surface of the substrate, an oxide film made of an oxide of a constituent element of the substrate. It is preferable that the oxide film thickness is 1 ?m or less. It is also preferable that the oxide film has a surface roughness Ra of 1.6 a or less.
    Type: Application
    Filed: February 17, 2011
    Publication date: December 6, 2012
    Applicant: HITACHI, LTD.
    Inventors: Hiroshi Haruyama, Masahiko Arai, Hiroyuki Doi, Takeshi Izumi
  • Patent number: 8225672
    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: Grant
    Filed: February 18, 2010
    Date of Patent: July 24, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Masahiko Arai, Shinichi Kobayasji, Hiroyuki Doi, Hiroaki Chiba, Takashi Haneishi
  • Publication number: 20120148389
    Abstract: A seal structure for a steam turbine is provided, which is capable of suppressing transfer of heat generated by a friction between a rotating portion and a fixed portion to the rotating portion and of suppressing an increase in the temperature of the rotating portion. A labyrinth seal device serves to suppress the amount of steam leaking from a clearance present between each stator blade (fixed portion) of the steam turbine and a rotor (rotating portion). The seal structure for the steam turbine is formed to ensure that permeable spacers made of a permeable metal are provided on the rotor and a seal stationary body and face respective seal fins provided in the labyrinth seal device.
    Type: Application
    Filed: February 14, 2012
    Publication date: June 14, 2012
    Applicant: HITACHI, LTD.
    Inventors: Kenjiro NARITA, Haruyuki YAMAZAKI, Hiroyuki DOI, Kei KOBAYASHI, Hajime TORIYA
  • Publication number: 20120141293
    Abstract: A Ni-based heat resistant alloy has a composition of, by mass percent, carbon: 0.001 to 0.1%, chromium: 16 to 22%, aluminum: 0.5 to 1.5%, molybdenum: 0.1 to 2.0%, tungsten: 0.1 to 6.0%, niobium: 3.5 to 5.5%, titanium: 0.8 to 3.0%, iron: 16 to 20%, and the balance being nickel and inevitable impurities. A parameter Ps indicating a segregation tendency is in a range of Ps??3.5. The parameter Ps is represented by Formula (1). Ps=1.05×Al content+0.6×Ti content?0.8×Nb content?0.
    Type: Application
    Filed: November 1, 2011
    Publication date: June 7, 2012
    Inventors: Jun Sato, Shinya Imano, Hiroyuki Doi
  • 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: 20120107103
    Abstract: A gas turbine shroud includes a ceramic abradable coating superior in abradable property and durability. The gas turbine ceramic abradable coating of the present invention is configured by an abradable metal layer and a porous ceramic abradable layer (hardness RC15Y: 80±3), the porous ceramic abradable layer is provided with slit grooves by machining work, and a slit groove width is 0.5 to 5 mm. Thereby, the abradable property, and durability against a thermal cycle and high-temperature oxidation are improved.
    Type: Application
    Filed: September 23, 2011
    Publication date: May 3, 2012
    Inventors: Yoshitaka Kojima, Hideyuki Arikawa, Akira Mebata, Tadashi Kasuya, Hiroyuki Doi, Kunihiro Ichikawa, Takao Endo, Kazuto Mikazuki, Hidetoshi Kuroki
  • Patent number: 8128351
    Abstract: A seal structure for a steam turbine is provided, which is capable of suppressing transfer of heat generated by a friction between a rotating portion and a fixed portion to the rotating portion and of suppressing an increase in the temperature of the rotating portion. A labyrinth seal device serves to suppress the amount of steam leaking from a clearance present between each stator blade (fixed portion) of the steam turbine and a rotor (rotating portion). The seal structure for the steam turbine is formed to ensure that permeable spacers made of a permeable metal are provided on the rotor and a seal stationary body and face respective seal fins provided in the labyrinth seal device.
    Type: Grant
    Filed: December 2, 2008
    Date of Patent: March 6, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Kenjiro Narita, Haruyuki Yamazaki, Hiroyuki Doi, Kei Kobayashi, Hajime Toriya
  • Publication number: 20110296685
    Abstract: In a gas turbine blade where a part of the ?? phase precipitation strengthened type Ni-based alloy base material is composed of a weld metal, the weld metal is a Ni-based alloy containing Ta from 4.8 to 5.3 wt. %, Cr from 18 to 23 wt. %, Co from 12 to 17 wt. %, W from 14 to 18 wt. %, C from 0.03 to 0.1 wt. %, Mo from 1 to 2 wt. %, and Al of 1 wt. % or less, in which the oxygen content is 0 to 30 ppm, the Ti content from 0 to 0.1 wt. %, and the Re content from 0 to 0.5 wt. %. A blade base metal is manufactured by the step of stripping, the step of solution heat treatment where the ?? phase is dissolved again, the step of welding in an inert gas chamber by a TIG method using a welding wire where the weld metal can be obtained, the step of HIP treatment at 1100° C. to 1150° C., and the step of an aging treatment at 835° C. to 855° C.
    Type: Application
    Filed: August 17, 2011
    Publication date: December 8, 2011
    Inventors: Shinya Imano, Kunihiro Ichikawa, Hiroyuki Doi, Katsumi Tanaka
  • Patent number: 8043068
    Abstract: A Ni—Fe based super alloy having high strength and toughness at high temperatures even when used in high-temperature environments, and a process of producing the super alloy. A turbine disk using the super alloy, a process of producing the turbine disk, a turbine spacer using the super alloy, and a process of producing the turbine spacer, as well as a gas turbine are also provided. The Ni—Fe based super alloy contains not more than 0.03% by weight of C, 14-18% of Cr, 15-45% of Fe, 0.5-2.0% of Al, not more than 0.05% of N, 0.5 to 2.0% of Ti, 1.5-5.0% of Nb, and Ni as a main ingredient.
    Type: Grant
    Filed: August 18, 2005
    Date of Patent: October 25, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Shinya Imano, Hiroyuki Doi, Isao Takehara, Shigeo Sakurai