Hitachi, Ltd.

Soichi Kurosawa

Nobuyuki Iizuka

Yutaka Fukui

Yasuo Watanabe

Masao Siga

Ryo Hiraga

Mitsuo Kuriyama

Kazuhiko Kumata

Shintaro Takahashi

Katsumi Iijima

Yosimi Maeno

Shigeyoshi Nakamura

Katsuo Wada

Tetsuo Kashimura

Mitsuo Teranishi

Minoru Morikawa

Masashi Kunihiro

A heat resistant steel of the present invention contains 0.05 to 0.2 wt. % of C, less than 0.5 wt. % of Si, less than 0.6 wt. % of Mn, 8 to 13 wt. % of Cr, 1.5 to 3 wt. % of Mo, 2 to 3 wt. % of Ni, 0.05 to 0.3 wt. % of V, 0.02 to 0.2 wt. % in total of either or both of Nb and Ta, 0.02 to 0.1 wt. % of N and the balance substantially Fe. Since a gas turbine of the present invention is constituted by members, such as discs, blades, shafts and so forth, made of alloys of this kind, the gas turbine has a structure in which it is possible to achieve a high level of creep rupture strength and Charpy impact value.

Heat resistant steel and gas turbine components composed of the same

A method and apparatus for controlling a temperature of a turbine casing and a turbine rotor in a gas turbine, which method and apparatus enables a maintaining of an optimum gap at a tip end of the rotor blades of the gas turbine over an entire operating range by independently controlling the amounts of heat energy supplied to a space of the turbine casing and the turbine rotor.

Method and apparatus for controlling temperatures of turbine casing and

Gas turbine having components composed of heat resistant steel

A cobalt-base alloy comprises 0.2-1 wt % C 0.4-2 wt % Si, 0.2-1.5 wt % Mn, 5-15 wt % Ni, 20-35 wt % Cr, 3-15 wt % W, 0.003-0.1 wt % Ni, 20-35 wt % Cr, 3-15 wt % W, 0.003-0.1 wt % B, 0.05-1 wt % Nb, 0.01-1 wt % Ta, 2 wt % or less Fe, 30 ppm or less oxygen, 100 ppm or less nitrogen, and the balance of 45 wt % or more Co, wherein the content of Si is larger than that of Mn. The alloy is in a form of casting and has a structure containing a eutectic carbide and a secondary carbide dispersed therein. The cast alloy is produced through solution treatment at 1,100.degree.-1.200.degree. C., and aging treatment at 950.degree.-1,050.degree. C., and cooling rate after the solution treatment and after the aging treatment is 150.degree. to 300.degree. C./h. A gas turbine nozzle is made of a casting of the above-mentioned alloy.

Cobalt-base alloy having high strength and high toughness, production

Stator blades and rotor blades are cooled by discharge air discharged from an air compressor coupled directly with gas turbine. A signal of the compressor discharge pressure and a signal of turbine exhaust gas temperature are obtained, and cooling air flow is controlled based on these signals.

Cooling air flow controlling apparatus for gas turbine

A turbine rotor provided with a sealing member for preventing air leaks through a gap between the under side surface of a projection extending from one of discs of the rotor and the upper side surface of a outward end portion of the spacer interposed between the discs. The spacer is formed with an annular groove on the upper side surface of the outward end portion for receiving a sealing wire in its entirety. The sealing wire has its outer portion forced against the underside surface of the projection by centrifugal forces while its inner portion remains inside the groove during turbine operation, to thereby seal the gap to prevent leaks of air therethrough.

Turbine rotor with means for preventing air leaks through outward end of

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Hitachi, Japan

Soichi Kurosawa