Patents by Inventor Hisashi Amaya

Hisashi Amaya 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: 20190177823
    Abstract: A steel bar for a downhole member is provided that is excellent in SCC resistance and SSC resistance. A martensitic stainless steel bar material for a downhole member of the present embodiment has a chemical composition that contains, by mass %, C: 0.020% or less, Si: 1.0% or less, Mn: 1.0% or less, P: 0.03% or less, S: 0.01% or less, Cu: 0.10 to 2.50%, Cr: 10 to 14%, Ni: 1.5 to 7.0%, Mo: 0.2 to 3.0%, Ti: 0.05 to 0.3%, V: 0.01 to 0.10%, Nb: 0.1% or less, Al: 0.001 to 0.1% and N: 0.05% or less, with the balance being Fe and impurities, and satisfies Formula (1) and Formula (2). [Mo]?4×[total Mo amount in precipitate at R/2 position]?1.30??(1) [Total Mo amount in precipitate at center position]?[total Mo amount in precipitate at R/2 position]?0.
    Type: Application
    Filed: May 19, 2017
    Publication date: June 13, 2019
    Inventors: Daisuke MATSUO, Takuii NAKAHATA, Hisashi AMAYA, Tsutomu OKUYAMA, Hideki TAKABE
  • Patent number: 10000832
    Abstract: Provided is duplex stainless steel having high strength, SCC resistance and SSC resistance excellent in a high-temperature chloride environment, and capable of suppressing precipitation of a ? phase. The duplex stainless steel of the present embodiment includes, in mass %, of: C: at most 0.03%; Si: 0.2 to 1%; Mn: more than 5.0% to at most 10%; P: at most 0.040%; S: at most 0.010%; Ni: 4.5 to 8%; sol. Al: at most 0.040%; N: more than 0.2% to at most 0.4%; Cr: 24 to 29%; Mo: 0.5 to less than 1.5%; Cu: 1.5 to 3.5%; W: 0.05 to 0.2%; the balance being Fe and impurities, wherein the duplex stainless steel satisfies Formula (1): Cr+8Ni+Cu+Mo+W/2?65 . . . (1), where a symbol of each element in Formula (1) represents a content of the element (in mass %).
    Type: Grant
    Filed: August 28, 2012
    Date of Patent: June 19, 2018
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Hideki Takabe, Hisashi Amaya, Kazuhiro Ogawa
  • Patent number: 9783876
    Abstract: A stainless steel for oil wells which has excellent high-temperature corrosion resistance and can stably obtain a strength of not less than 758 MPa is provided. The stainless steel for oil wells contains, by masse, C: not more than 0.05%, Si: not more than 1.0%, Mn: 0.01 to 1.0%, P: not more than 0.05%, S: less than 0.002%, Cr: 16 to 18%, Mo: 1.8 to 3%, Cu: 1.0 to 3.5%, Ni: 3.0 to 5.5%, Co: 0.01 to 1.0%, Al: 0.001 to 0.1%, O: not more than 0.05%, and N: not more than 0.05%, the balance being Fe and impurities, and satisfies Formulas (1) and (2): Cr+4Ni+3Mo+2Cu?44??(1) Cr+3Ni+4Mo+2Cu/3?46??(2) where each symbol of element in Formulas (1) and (2) is substituted by the content (mass %) of a corresponding element.
    Type: Grant
    Filed: February 27, 2013
    Date of Patent: October 10, 2017
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Shinjiro Nakatsuka, Taro Ohe, Hisashi Amaya, Hideki Takabe, Yohei Otome, Yusaku Tomio, Masanao Seo, Tomohiko Omura, Kunio Kondo
  • Patent number: 9771628
    Abstract: Provided is a duplex stainless steel having a high strength and a high toughness. A stainless steel according to the present invention includes: a chemical composition containing, in mass percent, C: at most 0.030%, Si: 0.20 to 1.00%, Mn: at most 8.00%, P: at most 0.040%, S: at most 0.0100%, Cu: more than 2.00% and at most 4.00%, Ni: 4.00 to 8.00%, Cr: 20.0 to 30.0%, Mo: at least 0.50% and less than 2.00%, N: 0.100 to 0.350%, and sol. Al: at most 0.040%, the balance being Fe and impurities; and a structure, wherein a rate of ferrite in the structure is 30 to 70%, and a hardness of the ferrite in the structure is at least 300 Hv10gf.
    Type: Grant
    Filed: February 10, 2012
    Date of Patent: September 26, 2017
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Daisuke Motoya, Masahiko Hamada, Hisashi Amaya, Hiroyuki Nagayama, Kenta Yamada
  • Patent number: 9579870
    Abstract: A welded joint of duplex stainless steel, which can suppress precipitation ? phase under high heat input welding, is excellent in SCC resistance under high-temperature chloride environments. A weld metal of the welded joint contains, in mass percent, C: at most 0.030%, Si: 0.20 to 1.00%, Mn: at most 8.00%, P: at most 0.040%, S: at most 0.0100%, Cu: at most 2.00%, Ni: 7.00 to 12.00%, Cr: 20.0 to 30.0%, Mo: 1 to 4%, N: 0.100 to 0.350%, sol. Al: at most 0.040%, and O: at most 0.035%, the balance being Fe and impurities. The weld metal satisfies Expressions (1) and (3): 2.2Cr+7Mo+3Cu>66??(1) Cr+11Mo+10Ni?12(Cu+30N)<100??(3) where a content (mass percent) of each element in one of the base metal and weld metal is used for each element in Expressions (1) and (3).
    Type: Grant
    Filed: February 10, 2012
    Date of Patent: February 28, 2017
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Hiroyuki Nagayama, Kenta Yamada, Masahiko Hamada, Daisuke Motoya, Hisashi Amaya
  • Patent number: 9555496
    Abstract: A process for producing a welded joint, which includes a weld metal having high strength and high toughness, and containing fewer blowholes, includes the steps of: preparing a base material containing, by mass %, not less than 10.5% of Cr; and subjecting the base material to GMA welding using a shielding gas containing 1 to 2 volume % or 35 to 50 volume % of CO2 gas, and the balance being inert gas, thereby forming a weld metal includes, by mass %, C: not more than 0.080%, Si: 0.20 to 1.00%, Mn: not more than 8.00%, P: not more than 0.040%, S: not more than 0.0100%, Cu: not more than 2.0%, Cr: 20.0 to 30.0%, Ni: 7.00 to 12.00%, N: 0.100 to 0.350%, O: 0.02 to 0.11%, sol. Al: not more than 0.040%, at least one of Mo: 1.00 to 4.00% and W: 1.00 to 4.00%, and the balance being Fe and impurities.
    Type: Grant
    Filed: March 27, 2013
    Date of Patent: January 31, 2017
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Kenta Yamada, Masahiko Hamada, Daisuke Motoya, Shinjiro Nakatsuka, Hisashi Amaya, Hideki Takabe
  • Patent number: 9322087
    Abstract: The chemical composition of a stainless steel in accordance with the present invention consists of C: not more than 0.05%, Si: not more than 0.5%, Mn: 0.01 to 0.5%, P: not more than 0.04%, S: not more than 0.01%, Cr: more than 16.0 and not more than 18.0%, Ni: more than 4.0 and not more than 5.6%, Mo: 1.6 to 4.0%, Cu: 1.5 to 3.0%, Al: 0.001 to 0.10%, and N: not more than 0.050%, the balance being Fe and impurities, and satisfies Formulas (1) and (2). Also, the micro-structure thereof contains a martensitic phase and a ferritic phase having a volume ratio of 10 to 40%, and the ferritic phase distribution ratio is higher than 85%. Cr+Cu+Ni+Mo ?25.5??(1) ?8 ?30(C+N)+0.5Mn+Ni+Cu/2+8.2?1.
    Type: Grant
    Filed: July 8, 2015
    Date of Patent: April 26, 2016
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Hideki Takabe, Kunio Kondo, Hisashi Amaya, Taro Ohe, Yohei Otome
  • Patent number: 9303296
    Abstract: A high-strength stainless steel for oil well having corrosion resistance excellent in a high-temperature environment, having excellent SSC resistance at normal temperature, and having better workability than 13% Cr steels has a chemical composition containing, by mass percent, C: at most 0.05%, Si: at most 1.0%, Mn: at most 0.3%, P: at most 0.05%, S: less than 0.002%, Cr: over 16% and at most 18%, Mo: 1.5 to 3.0%, Cu: 1.0 to 3.5%, Ni: 3.5 to 6.5%, Al: 0.001 to 0.1%, N: at most 0.025%, and O: at most 0.01%, the balance being Fe and impurities, a microstructure containing a martensite phase, 10 to 48.5%, by volume ratio, of a ferrite phase and at most 10%, by volume ratio, of a retained austenite phase, yield strength of at least 758 MPa and uniform elongation of at least 10%.
    Type: Grant
    Filed: September 10, 2012
    Date of Patent: April 5, 2016
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Taro Ohe, Hisashi Amaya, Hideki Takabe, Kunio Kondo, Yohei Otome
  • Publication number: 20150307972
    Abstract: The chemical composition of a stainless steel in accordance with the present invention consists of C: not more than 0.05%, Si: not more than 0.5%, Mn: 0.01 to 0.5%, P: not more than 0.04%, S: not more than 0.01%, Cr: more than 16.0 and not more than 18.0%, Ni: more than 4.0 and not more than 5.6%, Mo: 1.6 to 4.0%, Cu: 1.5 to 3.0%, Al: 0.001 to 0.10%, and N: not more than 0.050%, the balance being Fe and impurities, and satisfies Formulas (1) and (2). Also, the micro-structure thereof contains a martensitic phase and a ferritic phase having a volume ratio of 10 to 40%, and the ferritic phase distribution ratio is higher than 85%. Cr+Cu+Ni+Mo 25.5??(1) ?8 ?30(C+N)+0.5Mn+Ni+Cu/2+8.2?1.
    Type: Application
    Filed: July 8, 2015
    Publication date: October 29, 2015
    Inventors: Hideki TAKABE, Kunio KONDO, Hisashi AMAYA, Taro OHE, Yohei OTOME
  • Patent number: 9109268
    Abstract: The chemical composition of a stainless steel in accordance with the present invention consists of C: not more than 0.05%, Si: not more than 0.5%, Mn: 0.01 to 0.5%, P: not more than 0.04%, S: not more than 0.01%, Cr: more than 16.0 and not more than 18.0%, Ni: more than 4.0 and not more than 5.6%, Mo: 1.6 to 4.0%, Cu: 1.5 to 3.0%, Al: 0.001 to 0.10%, and N: not more than 0.050%, the balance being Fe and impurities, and satisfies Formulas (1) and (2). Also, the micro-structure thereof contains a martensitic phase and a ferritic phase having a volume ratio of 10 to 40%, and the ferritic phase distribution ratio is higher than 85%. Cr+Cu+Ni+Mo?25.5??(1) ?8?30(C+N)+0.5Mn+Ni+Cu/2+8.2?1.
    Type: Grant
    Filed: October 19, 2011
    Date of Patent: August 18, 2015
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Hideki Takabe, Kunio Kondo, Hisashi Amaya, Taro Ohe, Yohei Otome
  • Patent number: 9090957
    Abstract: A martensitic stainless steel oil country tubular good contains, by mass, 0.005% to 0.1% C, 0.05% to 1% Si, 1.5% to 5% Mn, at most 0.05% P, at most 0.01% S, 9% to 13% Cr, at most 0.5% Ni, at most 2% Mo, at most 2% Cu, 0.001% to 0.1% Al, and 0.001% to 0.1% N, with the balance being Fe and impurities, and the pipe has a Cr-depleted region under the surface. The martensitic stainless steel oil country tubular good according to the present invention does not have a passive film on the surface and corrodes wholly at low speed. In addition, the Ni content is reduced, which allows uneven corrosion to be prevented. Therefore, SCC can be prevented from being generated in spite of the presence of a Cr-depleted region.
    Type: Grant
    Filed: December 7, 2004
    Date of Patent: July 28, 2015
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Hisashi Amaya, Kunio Kondo, Masakatsu Ueda
  • Patent number: 9034125
    Abstract: A method for manufacturing an Ni base alloy pipe stock comprises piercing and rolling a billet by use of Mannesmann piercing and rolling mill. The pipe stock has controlled amounts of C, Si, Mn, P, S, Cr, Ni, Mo, W, Cu, Al, N, with the balance being Fe. With the method, the following equations are satisfied, wherein values of TGBm, Psr and P? represented by the following equations (1) to (3) being not more than 1300, not more than 200 and not less than 0, respectively TGBm=1380?5000P?100S?4400C??(1), PsrNi+10(Mo+0.5W)+100N??(2), P?=(Ni?50)+10(N?0.1)?2(Cr?25)?5(Mo+0.5W?6)+12??(3), wherein each element symbol in the equations represents mass % of the element concerned.
    Type: Grant
    Filed: June 14, 2013
    Date of Patent: May 19, 2015
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Masaaki Igarashi, Kazuhiro Shimoda, Tomio Yamakawa, Hisashi Amaya Amaya
  • Publication number: 20150056005
    Abstract: Provided is a process for producing a welded joint which includes a weld metal having high strength and high toughness, and containing fewer blowholes. The process for producing a welded joint according to the present embodiment includes the steps of: preparing a base material containing, by mass %, not less than 10.5% of Cr; and subjecting the base material to GMA welding using a shielding gas containing 1 to 2 volume % or 35 to 50 volume % of CO2 gas, and the balance being inert gas, thereby forming a weld metal includes, by mass %, C: not more than 0.080%, Si: 0.20 to 1.00%, Mn: not more than 8.00%, P: not more than 0.040%, S: not more than 0.0100%, Cu: not more than 2.0%, Cr: 20.0 to 30.0%, Ni: 7.00 to 12.00%, N: 0.100 to 0.350%, O: 0.02 to 0.11%, sol. Al: not more, than 0.040%, at least one of Mo: 1.00 to 4.00% and W: 1.00 to 4.00%, and the balance being Fe and impurities.
    Type: Application
    Filed: March 27, 2013
    Publication date: February 26, 2015
    Applicant: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Kenta Yamada, Masahiko Hamada, Daisuke Motoya, Shinjiro Nakatsuka, Hisashi Amaya, Hideki Takabe
  • Publication number: 20150047831
    Abstract: A stainless steel for oil wells which has excellent high-temperature corrosion resistance and can stably obtain a strength of not less than 758 MPa is provided. The stainless steel for oil wells contains, by masse, C: not more than 0.05%, Si: not more than 1.0%, Mn: 0.01 to 1.0%, P: not more than 0.05%, S: less than 0.002%, Cr: 16 to 18%, Mo: 1.8 to 3%, Cu: 1.0 to 3.5%, Ni: 3.0 to 5.5%, Co: 0.01 to 1.0%, Al: 0.001 to 0.1%, O: not more than 0.05%, and N: not more than 0.05%, the balance being Fe and impurities, and satisfies Formulas (1) and (2): Cr+4Ni+3Mo+2Cu?44??(1) Cr+3Ni+4Mo+2Cu/3?46??(2) where each symbol of element in Formulas (1) and (2) is substituted by the content (mass %) of a corresponding element.
    Type: Application
    Filed: February 27, 2013
    Publication date: February 19, 2015
    Inventors: Shinjiro Nakatsuka, Taro Ohe, Hisashi Amaya, Hideki Takabe, Yohei Otome, Yusaku Tomio, Masanao Seo, Tomohiko Omura, Kunio Kondo
  • Publication number: 20140212322
    Abstract: Provided is duplex stainless steel having high strength, SCC resistance and SSC resistance excellent in a high-temperature chloride environment, and capable of suppressing precipitation of a ? phase. The duplex stainless steel of the present embodiment includes, in mass %, of: C: at most 0.03%; Si: 0.2 to 1%; Mn: more than 5.0% to at most 10%; P: at most 0.040%; S: at most 0.010%; Ni: 4.5 to 8%; sol. Al: at most 0.040%; N: more than 0.2% to at most 0.4%; Cr: 24 to 29%; Mo: 0.5 to less than 1.5%; Cu: 1.5 to 3.5%; W: 0.05 to 0.2%; the balance being Fe and impurities, wherein the duplex stainless steel satisfies Formula (1): Cr+8Ni+Cu+Mo+W/2?65 . . . (1), where a symbol of each element in Formula (1) represents a content of the element (in mass %).
    Type: Application
    Filed: August 28, 2012
    Publication date: July 31, 2014
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Hideki Takabe, Hisashi Amaya, Kazuhiro Ogawa
  • Patent number: 8784581
    Abstract: An Fe—Ni alloy pipe stock containing, by mass %, C?0.04%, Si?0.50%, Mn: 0.01 to 6.0%, P?0.03%, S?0.01%, Cr: 20 to 30%, Ni: 30 to 45%, Mo: 0 to 10%, W: 0 to 20%, with Mo(%)+0.5W(%): more than 1.5% to not more than 10%, Cu: 0.01 to 1.5%, Al?0.01% and N: 0.0005 to 0.20%, and the balance being Fe, with 1440?6000P?100S?2000C?1300, Ni+10(Mo+0.5W)+100N?120, (Ni?35)+10(N?0.1)?2(Cr?25)?5(Mo+0.5W?3)+8?0, can be manufactured into a seamless pipe by use of a Mannesmann piercing and rolling mill because of its excellent inner surface properties. The resulting seamless pipe has excellent mechanical properties and moreover has excellent corrosion resistance in a sour gas environment.
    Type: Grant
    Filed: December 22, 2006
    Date of Patent: July 22, 2014
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Masaaki Igarashi, Kazuhiro Shimoda, Tomio Yamakawa, Hisashi Amaya
  • Patent number: 8701455
    Abstract: A method for manufacturing a high alloy pipe comprises hot working, a high alloy material pipe having controlled amounts of C, Si, Mn, P, S, Ni, Cr, Mo, Cu, Al, N, O, and optionally Ca, Mg, and rare earth elements, with the balance Fe. The pipe composition satisfies the formula N×O?0.001. The pipe is subjected to cold working to form the high alloy pipe, wherein the final cold working process is performed under the condition that a working ratio Rd in the reduction of area satisfies 15?Rd (%)?370×(C+N), where N, O and C are the contents (by mass percent) of the respective elements, and Rd is the working ratio (%) in the reduction of area. The pipe has an excellent ductility and an excellent corrosion resistance when cold working is performed to obtain a high strength after pipe-making.
    Type: Grant
    Filed: December 31, 2009
    Date of Patent: April 22, 2014
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Masayuki Sagara, Hitoshi Suwabe, Hisashi Amaya, Shigemitsu Kimura, Masaaki Igarashi
  • Patent number: 8608872
    Abstract: The problem to be solved is the provision of a high-strength stainless steel pipe having a sufficient corrosion resistance in a high-temperature carbonic acid gas environment and having an excellent sulfide stress cracking resistance at normal temperature. A high-strength stainless steel pipe consist of, by mass %, C: 0.05% or less, Si: 1.0% or less, P: 0.05% or less, S: less than 0.002%, Cr: more than 16% and 18% or less, Mo: more than 2% and 3% or less, Cu: 1% to 3.5%, Ni: 3% or more and less than 5%, Al: 0.001% to 0.1% and O: 0.01% or less, Mn: 1% or less and N: 0.05% or less, and Mn and N in the above ranges satisfy formula (1), and the balance being Fe and impurities; and the metal micro-structure of the stainless steel pipe mainly includes a martensitic phase and comprises 10 to 40% of a ferritic phase by volume fraction and 10% or less of a retained ?-phase by volume fraction. [Mn]×([N]?0.0045)?0.
    Type: Grant
    Filed: April 8, 2011
    Date of Patent: December 17, 2013
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Kunio Kondo, Hisashi Amaya, Hideki Takabe, Taro Ohe
  • Publication number: 20130315776
    Abstract: A duplex stainless steel, which can suppress precipitation of a ? phase under high heat input welding, is excellent in SCC resistance under high-temperature chloride environments and has a high strength. The duplex stainless steel includes a chemical composition containing, in mass percent, C: at most 0.030%, Si: 0.20 to 1.00%, Mn: at most 8.00%, P: at most 0.040%, S: at most 0.0100%, Cu: more than 2.00% and at most 4.00%, Ni: 4.00 to 8.00%, Cr: 20.0 to 28.0%, Mo: 0.50 to 2.00%, N: 0.100 to 0.350%, and sol. Al: at most 0.040%, the balance being Fe and impurities, and satisfying Expression (1) and Expression (2); a structure having a ferrite rate of at least 50%; and a yield strength of at least 550 MPa or more: 2.
    Type: Application
    Filed: February 10, 2012
    Publication date: November 28, 2013
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Kenta Yamada, Hiroyuki Nagayama, Masahiko Hamada, Daisuke Motoya, Hisashi Amaya
  • Publication number: 20130316193
    Abstract: A welded joint of duplex stainless steel, which can suppress precipitation of ? phase under high heat input welding, is excellent in SCC resistance under high-temperature chloride environments. A weld metal of the welded joint contains, in mass percent, C: at most 0.030%, Si: 0.20 to 1.00%, Mn: at most 8.00%, P: at most 0.040%, S: at most 0.0100%, Cu: at most 2.00%, Ni: 7.00 to 12.00%, Cr: 20.0 to 30.0%, Mo: 1 to 4%, N: 0.100 to 0.350%, sol. Al: at most 0.040%, and O: at most 0.035%, the balance being Fe and impurities. The weld metal satisfies Expressions (1) and (3): 2.2Cr+7Mo+3Cu>66??(1) Cr+11Mo+10Ni?12(Cu+30N)<100??(3) where a content (mass percent) of each element in one of the base metal and weld metal is used for each element in Expressions (1) and (3).
    Type: Application
    Filed: February 10, 2012
    Publication date: November 28, 2013
    Inventors: Hiroyuki Nagayama, Kenta Yamada, Masahiko Hamada, Daisuke Motoya, Hisashi Amaya