Patents by Inventor Seishin Kirihara
Seishin Kirihara 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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Patent number: 5242264Abstract: The disclosure is concerned with a thermal land machine which comprises a heat resistant wall for confining a chamber; a heat resistant composite structure disposed in the chamber and in contact with a hot flowing gas; and an apparatus for introducing the hot gas toward the surface of the composite structure. The composite structure including a heat resistant substrate and a continuous refractory coating formed on the substrate and made of a ceramic material. The refractory coating includes at least two layers in a laminated structure each having fine cracks substantially extended in the direction of the thickness of each of the layers and filled with a refractory material in such a manner that the filled cracks in one layer are disconnected with the filled cracks in the adjacent layer. Therefore, the hot gas cannot permeate into the surface of the substrate.Type: GrantFiled: August 8, 1990Date of Patent: September 7, 1993Assignee: Hitachi, Ltd.Inventors: Yoshitaka Kojima, Noriyuki Ohnaka, Shizuka Yamaguchi, Shoichi Nakashima, Sai Ogawa, Masayuki Doi, Seishin Kirihara
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Patent number: 4802894Abstract: A structural member to be subjected to a hot gas atmosphere produced through reaction between coal and a gasifier such as oxygen, air, steam or hydrogen, in a gasification furnace for example. The structural member is made of an anti-sulfur attack Cr-Ni-Al-Si alloy steel which has a composition essentially consisting of, by weight, 0.03 to 0.3% of C, 1 to 10% of Si, not greater than 2.0% of Mn, 8 to 14% of Ni, 16 to 20% of Cr, 0.5 to 10% of Al and the balance not less than 50% of Fe.Type: GrantFiled: January 12, 1987Date of Patent: February 7, 1989Assignee: Hitachi, Ltd.Inventors: Kenichi Usami, Seishin Kirihara, Tadaoki Morimoto, Hiroyuki Doi, Michiya Okada
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Patent number: 4585478Abstract: A heat resisting steel suitable for use as the materials of steam turbine casings of steam turbines for thermal power generation. The steel has a composition consisting essentially of 0.05 to 0.2 wt % of C, 0.5 to 2.0 wt % of Cr, 0.5 to 2.0 wt % of Mo, 0.05 to 0.5 wt % of V, 0.002 to 0.1 wt % of Al, 0.0002 to 0.0030 wt % of B and the balance substantially Fe and inevitable impurities, wherein the sum of X and Al as obtained from the following formulae is not greater than 2920:X=10P+5Sb+4Sn+AsAl=xAl(x being a coefficient obtained from FIG. 4)where, P,Sb,Sn and As represent the contents of P,Sb,Sn and As contained as said inevitable impurities in terms of ppm, while Al represents the Al content in terms of ppm. This heat resisting steel exhibits a large resistance to cracking in stress relief annealing after welding, as well as a high creep rupture strength at high temperature, and shows only a low crack developing speed.Type: GrantFiled: May 4, 1984Date of Patent: April 29, 1986Assignee: Hitachi, Ltd.Inventors: Takatoshi Yoshioka, Seishin Kirihara, Masao Siga, Mitsuo Kuriyama, Takehiko Yoshida, Takanori Murohoshi
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Patent number: 4581067Abstract: A high-strength austenitic steel having a fully austenite structure and consisting essentially of 0.02 to 0.15 wt % of C, not greater than 1.5 wt % of Si, not greater than 2.5 wt % of Mn, 8 to 20 wt % of Ni, 13 to 25 wt % of Cr, 0.02 to 0.25 wt % of Al, not greater than 0.1 wt % of N, at least one of 0.001 to 0.01 wt % of B, 0.02 to 0.5 wt % of Nb, 0.01 to 0.2 wt % of Ti and 0.02 to 0.6 wt % of V and the balance substantialy Fe, with the weight ratio (Al/N) ranging between 1 and 4.5. This steel is suitable for use as the material of, for example, inner casing of steam turbine, valve body incorporated in the steam turbine, rotor shaft, and chemical equipment such as reaction pipe and vessel for styrene monomer producing facility.Type: GrantFiled: November 1, 1983Date of Patent: April 8, 1986Assignee: Hitachi, Ltd.Inventors: Katsumi Iijima, Norio Yamada, Seishin Kirihara, Masao Shiga, Masayuki Sukekawa, Takatoshi Yoshioka, Kiyoshi Hiyama
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Patent number: 4566810Abstract: A steam turbine rotor shaft made of precipitation-hardened forged austenite steel, comprising first, second and succeeding layers of build-up welding provided on an outer surface of a bearing portion of a journal section in the rotor shaft, the first layer being provided by use of a welding rod of Ni base alloy, the second and succeeding layers being provided by use of a welding rod of low alloy steel which layers have better bearing characteristics than those of the austenite steel.Type: GrantFiled: April 12, 1983Date of Patent: January 28, 1986Assignee: Hitachi, Ltd.Inventors: Takatoshi Yoshioka, Seishin Kirihara, Masao Shiga, Katsumi Iijima, Katsukuni Hisano, Ryoichi Kaneko
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Patent number: 4505232Abstract: A boiler tube having a double-tube structure constituted by an inner tube and an outer tube integrated with each other. The inner tube is made of an alloy consisting essentially of, by weight, 0.02 to 0.15% of C, 0.5 to 3.5% of Si, not greater than 2% of Mn, 25 to 40% of Ni, 20.5 to 27% of Cr, 0.5 to 3% of Mo, not greater than 1% of Nb and the balance Fe and having a substantially fully austenite structure. The outer tube is made of an alloy consisting essentially of, by weight, 0.02 to 0.2% of C, not greater than 3.5% of Si, not greater than 2% of Mn, 33 to 45% of Ni, 30 to 40% of Cr and the balance Fe and having a substantially fully austenite structure. The inner tube made of the alloy having the composition specified above exhibits a high resistance to steam oxidation without any reduction in high-temperature strength even at elevated steam temperature, while the outer tube made of the alloy having the composition specified above exhibits a superior resistance to corrosion by coal combustion gas.Type: GrantFiled: March 27, 1984Date of Patent: March 19, 1985Assignees: Hitachi, Ltd., Babcock-Hitachi Kabushiki KaishaInventors: Kenichi Usami, Seishin Kirihara, Hiroyuki Doi, Choichi Asano, Masayuki Sukekawa, Yasuhide Sakaguchi
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Patent number: 4504554Abstract: A steam turbine rotor shaft comprising the main body of the rotor shaft made of a high Cr steel of martensite structure, and a journal having a plurality of built-up welding layers formed successively said main body, the outer surface portion of the journal being made of steel containing 0.5 to 3 wt % of Cr, and a method of producing same.Type: GrantFiled: March 30, 1982Date of Patent: March 12, 1985Assignee: Hitachi, Ltd.Inventors: Takatoshi Yoshioka, Seishin Kirihara, Masao Siga, Takehiko Yoshida, Katsukuni Hisano, Toshimi Tan, Masahiro Kobayashi
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Patent number: 4497670Abstract: A rotor shaft for steam turbines has a journal portion to be supported by a bearing. The journal portion is provided with a sleeve for a bearing made of an alloy of bainite structure comprising 0.04 to 0.35% C, 0.2 to 2% Mn, less than 1% Si, 0.5 to 3% Cr, less than 5% Ni, and less than 0.5% V, having yield strength of more than 50 kg/mm.sup.2 and Lt of less than 24. The sleeve is divided into two semicylindrical segments, and they are arranged on a small diameter portion of the shaft adjacent to said journal portion, welded into one piece, and subjected to stress relief treatment at a temperature higher than a temperature of tempering conducted to the sleeve before welding. The welded sleeve is fitted on the journal portion by shrink-fit so that the sleeve can be served as a superior bearing.Type: GrantFiled: February 4, 1983Date of Patent: February 5, 1985Assignee: Hitachi, Ltd.Inventors: Masao Siga, Seishin Kirihara, Takatoshi Yoshioka, Katsukuni Hisano, Toshimi Tan, Yoji Akutsu, Kei Kobayashi
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Patent number: 4477280Abstract: A heat resisting steel suitable for use as material of steam turbine parts. The steel has a substantially whole tempered martensite structure and consisting essentially of, by weight, 8 to 13% of Cr, 0.5 to 2% of Mo, 0.02 to 0.5% of V, 0.02 to 0.15% of Nb, 0.025 to 0.1% of N, 0.05 to 0.25% of C, not greater than 0.6% of Si, not greater than 1.5% of Mn, not greater than 1.5% of Ni, 0.0005 to 0.02% of Al, 0.1 to 0.5% of W and the balance substantially Fe, the ratio W/Al between W content and Al content ranging between 10 and 110.Type: GrantFiled: December 22, 1982Date of Patent: October 16, 1984Assignee: Hitachi, Ltd.Inventors: Masao Shiga, Seishin Kirihara, Mitsuo Kuriyama, Takatoshi Yoshioka, Ryoichi Sasaki
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Patent number: 4443406Abstract: A heat-resistant and corrosion-resistant weld metal alloy consisting essentially of, by weight, less than 0.08% of C, 0.1 to 1.0% of Si, 2 to 3% of Mn, 32 to 42% of Ni, 21 to 25% of Cr, 0.8 to 1.7% of Mo, 0.1 to 1.0% of Nb, up to 0.5% of Ti, up to 2% of Co, up to 2% of Cu, up to 1% of W, up to 0.2% of N, up to 1.0% of V, up to 1.0% of Zr, up to 1.0% of Ta and the balance Fe, wherein the following conditions are met: Ti+Zr.ltoreq.1.0%, Ni+Co.ltoreq.42%, W+V.ltoreq.1.0%, Nb+Ta.ltoreq.1.0%, and 4.ltoreq.Nb/C.ltoreq.15; and an austenitic welded structure composed of an austenitic structural alloy and of a weld metal of the above-mentioned kind are provided by the invention.Type: GrantFiled: May 24, 1982Date of Patent: April 17, 1984Assignees: Hitachi, Ltd., Babcock-Hitachi Kabushiki KaishaInventors: Masayuki Sukekawa, Yoshimitsu Tobita, Seishin Kirihara, Hisashi Morimoto, Kenichi Usami, Katsumi Iijima
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Patent number: 4426162Abstract: A rotor shaft suitable for use as the rotor shaft of a steam turbine. The rotor shaft has a rotor shaft portion made of a Cr alloy steel having martensite structure and containing 8 to 13% Cr. The rotor shaft body is provided with at least one journal portion at which the rotor shaft is rotatably supported by a bearing. The rotor shaft further has a sleeve fitted around each journal portion. The sleeve is divided in the circumferential direction into a plurality of segments which are assembled together by welding or fitting into the sleeve having a circular cross-section. Due to the provision of the sleeve around the journal portion, the rotor shaft made of Cr alloy steel can have improved bearing properties.Type: GrantFiled: December 1, 1981Date of Patent: January 17, 1984Assignee: Hitachi, Ltd.Inventors: Keiichi Tsuchiya, Katsukuni Hisano, Toshimi Tan, Masahiro Kobayashi, Kei Kobayashi, Kazuhiko Ueda, Seishin Kirihara, Takatoshi Yoshioka, Masao Shiga
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Patent number: 4414024Abstract: This invention discloses martensitic heat-resistant steel consisting essentially of 0.1 to 0.2 wt. % of C, up to 0.4 wt. % of Si, up to 1 wt. % of Mn, 9 to 12 wt. % of Cr, 0.1 to 0.3 wt. % of V, 0.02 to 0.25 wt. % of Nb, 0.03 to 0.1 wt. % of N, up to 1 wt. % of Ni, molybdenum and tungsten in amounts falling within the range encompassed by lines connecting a point A (0.7 wt. % of Mo and 1.1 wt. % of W), a point B (1.2 wt. % of Mo and 1.1 wt. % of W), a point C (1.6 wt. % of Mo and 0.33 wt. % of W) and a point D (0.7 wt. % of Mo and 0.33 and wt. % of W) as shown in FIG. 1 and the balance of iron.The martensitic heat-resistant steel in accordance with the present invention is suitable for use in steam turbine blades and rotor shafts.Type: GrantFiled: August 26, 1982Date of Patent: November 8, 1983Assignee: Hitachi, Ltd.Inventors: Masao Siga, Seishin Kirihara, Mitsuo Kuriyama, Takatoshi Yosioka, Shintaro Takahashi, Takehiko Yoshida
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Patent number: 4348131Abstract: A welded structure and a method for making same wherein a plurality of weld metals, such as martensitic steel and austenitic steel, differing in coefficient of thermal expansion from each other are deposited in a plurality of layers thicknesswise of the welded structure in a gap defined by structural members to be welded in such a manner that a layer of the weld metal of higher coefficient of thermal expansion is covered by a layer of the weld metal of lower coefficient of thermal expansion in a weld formed, to improve brittle fracture strength, fatigue strength and stress corrosion cracking resistance of the weld. By subjecting the welded structure to stress relief annealing treatment, it is possible to produce compressive stress on the surface of the layer of the weld metal of lower coefficient of thermal expansion.Type: GrantFiled: May 6, 1980Date of Patent: September 7, 1982Assignee: Hitachi, Ltd.Inventors: Shizuka Shimanuki, Toshimi Matsumoto, Hiroshi Sato, Tsutomu Onuma, Seishin Kirihara