Patents by Inventor Akitsugu Fujita
Akitsugu Fujita 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).
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Publication number: 20070264125Abstract: The present invention overcomes brittleness of various beryllium alloys including beryllium intermetallic compounds and thereby provides a lightweight material for gas turbines. It's achieved by employing an alloy consisting essentially of an alloy of any one or more intermetallic compounds selected from the group of Be12M, but Be13M if M is Zr, Be10M, and Be17M, where M is any one or more metallic elements selected from the group of Ti, V, Mo, W, Zr, Nb and Ta.Type: ApplicationFiled: July 29, 2005Publication date: November 15, 2007Applicant: NGK Insulators, Ltd.Inventors: Muneroni Uchida, Akitsugu Fujita
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Patent number: 6773519Abstract: In CrMoV based heat resistant steels and tungsten-containing CrMoV based heat resistant steels, trace impurities, such as phosphorus, sulfur, copper, aluminum, arsenic, tin, and antimony are reduced lower than a specific level. Furthermore, alloy steels having increased creep strengths in a creep test on an unnotched test piece by addition of trace impurities such as cobalt, niobium, tantalum, nitrogen, boron, or the like is used. The production process therefor includes heating a turbine rotor member having the specific composition at a temperature between 980° C. and 1100° C. at a part corresponding to the high-pressure part thereof and at a temperature between 850° C. and 980° C.Type: GrantFiled: December 4, 2002Date of Patent: August 10, 2004Assignee: Mitsubishi Heavy Industries, Ltd.Inventors: Akitsugu Fujita, Masatomo Kamada
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Patent number: 6755920Abstract: A low-alloy heat-resistant steel may be used to manufacturing a large element which has uniform superior high temperature properties through a surface layer to a center part. The low-alloy heat-resistant steel comprises carbon in an amount of 0.20 to 0.35% by weight, silicon in an amount of 0.005 to 0.35% by weight, manganese in an amount of 0.05 to 1.0% by weight, nickel in an amount of 0.05 to 0.3% by weight, chromium in an amount of 0.8 to 2.5% by weight, molybdenum in an amount of 0.1 to 1.5% by weight, tungsten in an amount of 0.1 to 2.5% by weight, vanadium in an amount of 0.05 to 0.3% by weight, phosphorus in an amount not greater than 0.012% by weight, sulfur in an amount not greater than 0.005% by weight, copper in an amount not greater than 0.10% by weight, aluminum in an amount not greater than 0.01% by weight, arsenic in an amount not greater than 0.01% by weight, tin in an amount not greater than 0.01% by weight, antimony in an amount not greater than 0.Type: GrantFiled: March 4, 2002Date of Patent: June 29, 2004Assignee: Mitsubishi Heavy Industries, Ltd.Inventors: Masatomo Kamada, Akitsugu Fujita, Yoshiyuki Ooba, Yoshihiro Okamura, Makoto Yamaguchi
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Publication number: 20030145916Abstract: A turbine rotor material, that has sufficient corrosion resistance and stress corrosion cracking resistance and appropriate strength and toughness in a good balance, and a manufacturing method thereof are provided. The turbine rotor material is a 12Cr alloy steel that contains: C of 0.01 to 0.10%, Si of 0.01 to 0.50%, Mn of 0.1 to 1.0%, Cr of 9 to 13%, Ni of 2 to 7%, Mo of 0.3 to 3%, N of 0.01 to 0.10%, all in weight percent, and remains of Fe and incidental impurities.Type: ApplicationFiled: October 25, 2002Publication date: August 7, 2003Inventors: Masatomo Kamada, Masahiro Saito, Akitsugu Fujita, Yusaku Takano
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Publication number: 20030116240Abstract: In CrMoV based heat resistant steels and tungsten-containing CrMoV based heat resistant steels, trace impurities, such as phosphorus, sulfur, copper, aluminum, arsenic, tin, and antimony are reduced lower than a specific level. Furthermore, alloy steels having increased creep strengths in a creep test on an unnotched test piece by addition of trace impurities such as cobalt, niobium, tantalum, nitrogen, boron, or the like is used. The production process therefor includes heating a turbine rotor member having the specific composition at a temperature between 980° C. and 1100° C. at a part corresponding to the high-pressure part thereof and at a temperature between 850° C. and 980° C.Type: ApplicationFiled: December 4, 2002Publication date: June 26, 2003Applicant: MITSUBISHI HEAVY INDUSTRIES LTD.Inventors: Akitsugu Fujita, Masatomo Kamada
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Patent number: 6569269Abstract: In CrMoV based heat resistant steels and tungsten-containing CrMoV based heat resistant steels, trace impurities, such as phosphorus, sulfur, copper, aluminum, arsenic, tin, and antimony are reduced lower than a specific level. Furthermore, alloy steels having increased creep strengths in a creep test on an unnotched test piece by addition of trace impurities such as cobalt, tantalum, nitrogen, boron, or the like is used. The production process therefor includes heating a turbine rotor member having the specific composition at a temperature between 980° C. and 1100° C. at a part corresponding to the high-pressure part thereof and at a temperature between 850° C. and 980° C.Type: GrantFiled: November 14, 2000Date of Patent: May 27, 2003Assignee: Mitsubishi Heavy Industries, Ltd.Inventors: Akitsugu Fujita, Masatomo Kamada
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Publication number: 20030034101Abstract: A low-alloy heat-resistant steel may be used to manufacturing a large element which has uniform superior high temperature properties through a surface layer to a center part. The low-alloy heat-resistant steel comprises carbon in an amount of 0.20 to 0.35% by weight, silicon in an amount of 0.005 to 0.35% by weight, manganese in an amount of 0.05 to 1.0% by weight, nickel in an amount of 0.05 to 0.3% by weight, chromium in an amount of 0.8 to 2.5% by weight, molybdenum in an amount of 0.1 to 1.5% by weight, tungsten in an amount of 0.1 to 2.5% by weight, vanadium in an amount of 0.05 to 0.3% by weight, phosphorus in an amount not greater than 0.012% by weight, sulfur in an amount not greater than 0.005% by weight, copper in an amount not greater than 0.10% by weight, aluminum in an amount not greater than 0.01% by weight, arsenic in an amount not greater than 0.01% by weight, tin in an amount not greater than 0.01% by weight, antimony in an amount not greater than 0.Type: ApplicationFiled: March 4, 2002Publication date: February 20, 2003Applicant: MITSUBISHI HEAVY INDUSTRIES LTD.Inventors: Masatomo Kamada, Akitsugu Fujita, Yoshiyuki Ooba, Yoshihiro Okamura, Makoto Yamaguchi
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Patent number: 6254697Abstract: The present invention provides a cast steel material for pressure vessels which has improved impact resistance (weldability) and toughness while maintaining its creep rupture strength at a level equal to or higher than the excellent creep rupture strength currently possessed by CrMoV cast steel, as well as a method of making a pressure vessel (or cast steel article) by using this cast steel material which permits a pressure vessel to be made without requiring a material working step such as forging. Specifically, the present invention relates to a cast steel material for pressure vessels which contains C, Si, Mn, Ni, Cr, Mo, V, W, Nb and/or Ta, B, Ti, Al, N, O, P and S in predetermined proportions, the balance being Fe and incidental impurities, provided that the contents of Ti, Al, O and N satisfies the following relationship: N−0.29{Ti−1.5((O−0.89Al)}≦0.Type: GrantFiled: March 16, 2000Date of Patent: July 3, 2001Assignee: Mitsubishi Heavy Industries, Ltd.Inventors: Yasunori Tashiro, Masakatsu Ueno, Akitsugu Fujita, Masatomo Kamada
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Patent number: 6123897Abstract: A heat resistant material and a pressure vessel by use thereof, having an excellent high temperature strength so as to be applicable to steam condition of 600.degree. C. or more, are provided. Said material consists of C, Si, Cr, Ni, V, Nb, N, Mo and W in the respective weight percent, and inevitable impurities and Fe, and is further added with Cu, B and Ca and/or Mn, Mn and Cu, B and Ca, in the respective weight percent. Also, a pressure vessel is formed of said materials.Type: GrantFiled: July 23, 1999Date of Patent: September 26, 2000Assignee: Mitsubishi Heavy Industries, Ltd.Inventors: Akitsugu Fujita, Masatomo Kamata, Yasunori Tashiro, Koji Morinaka
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Patent number: 6095756Abstract: This invention relates to high-Cr precision casting materials containing carbon, silicon, manganese, chromium, nickel, vanadium, niobium, nitrogen, molybdenum, tungsten, cobalt and optionally boron in specific weight proportions, the balance being iron and incidental impurities, as well as turbine blades made by a precision casting process using these materials. Thus, the present invention provides high-Cr precision casting materials which are capable of precision casting and, moreover, have excellent high-temperature strength, as well as inexpensive and highly reliable turbine blades made by using these casting materials and such turbine blades also having lighter weight.Type: GrantFiled: March 3, 1998Date of Patent: August 1, 2000Assignee: Mitsubishi Heavy Industries, Ltd.Inventors: Akitsugu Fujita, Masatomo Kamada, Hiroshi Yokota, Mitsuyoshi Tsuchiya, Yoshinori Tanaka
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Patent number: 6007767Abstract: A heat resistant material and a pressure vessel by use thereof, having an excellent high temperature strength so as to be applicable to steam condition of 600.degree. C. or more, are provided. Said material consists of C, Si, Cr, Ni, V, Nb, N, Mo and W in the respective weight percent, and inevitable impurities and Fe, and is further added with Cu, B and Ca and/or Mn, Mn and Cu, B and Ca, in the respective weight percent. Also, a pressure vessel is formed of said materials.Type: GrantFiled: January 16, 1998Date of Patent: December 28, 1999Assignee: Mitsubishi Heavy Industries, Ltd.Inventors: Akitsugu Fujita, Masatomo Kamata, Yasunori Tashiro, Koji Morinaka
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Patent number: 5997806Abstract: This invention provides a heat-resisting cast steel which is a high-Cr steel material having excellent high-temperature strength and hence suitable for use as a high-temperature steam turbine casing material capable of being used even at a steam temperature of 600.degree. C. or above. This heat-resisting cast steel contains, on a weight percentage basis, 0.07 to 0.15% carbon, 0.05 to 0.30% silicon, 0.1 to 1% manganese, 8 to 10% chromium, 0.01 to 0.2% nickel, 0.1 to 0.3% vanadium, a total of 0.01 to 0.2% niobium and tantalum, 0.1 to 0.7% molybdenum, 1 to 2.5% tungsten, 0.1 to 5% cobalt and 0.03 to 0.07% nitrogen, the balance being iron and incidental impurities.Type: GrantFiled: June 24, 1998Date of Patent: December 7, 1999Assignee: Mitsubishi Heavy Industries, Ltd.Inventors: Akitsugu Fujita, Masatomo Kamada
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Patent number: 5972287Abstract: Disclosed is a heat-resisting steel comprising 0.05 to 0.15% by weight of carbon, 0.01 to 0.1% by weight of silicon, 0.01 to 1% by weight of manganese, 8 to 11% by weight of chromium, 0.1 to 0.8% by weight of nickel, 0.1 to 0.3% by weight of vanadium, a total of 0.01 to 0.2% by weight of niobium and tantalum, 0.001 to 0.01% by weight of nitrogen, 0.01 to 0.5% by weight of molybdenum, 0.9 to 3.5% by weight of tungsten, 0.1 to 4.5% by weight of cobalt, 0.001 to 0.01% by weight of boron, and the balance being iron and incidental impurities, as well as other similar heat-resisting steels. Thus, this invention provides heat-resisting steels which are 12Cr steel-based materials having excellent high-temperature strength and can be used at steam temperatures of 593.degree. C. or above, and forged steel products such as steam turbine rotors for high-temperature use.Type: GrantFiled: June 23, 1998Date of Patent: October 26, 1999Assignee: Mitsubishi Heavy Industries, Ltd.Inventors: Akitsugu Fujita, Fujimitsu Masuyama, Masatomo Kamada
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Patent number: 5599408Abstract: .epsilon. phase precipitates in the matrix having a composition of 0.07% or less carbon, 1 or less silicon, 1% or less manganese, 2.5 to 5% copper, 3 to 5.5% nickel, 14 to 17.5% chromium, 0.5% or less molybdenum, 0.15 to 0.45% niobium, by weight, and the balance composed substantially of iron, and comprising 6 to 30 vol % austenitic phase and the balance composed substantially of martensitic phase. In a method of producing a structural member in which first solution treatment is performed at 1010.degree. to 1050.degree. C. on a stainless steel having a composition described above and first aging treatment is performed at a temperature not lower than 520.degree. C. and not higher than 630.degree. C., second solution treatment is performed at 730.degree. to 840.degree. C., and then second aging treatment is performed at a temperature not lower than 520.degree. C. and not higher than 630.degree. C. or a structural member of any shape is fabricated by means of welding work before the second solution treatment.Type: GrantFiled: May 4, 1994Date of Patent: February 4, 1997Assignee: Mitsubishi Jukogyo Kabushiki KaishaInventors: Akitsugu Fujita, Takayuki Kawano, Makoto Nakamura, Fumikazu Sakai, Tatsuki Matsumoto, Shinsuke Oba, Hidetoshi Sueoka, Manabu Kimura, Masato Zama, deceased