Kabushiki Kaisha Toshiba

The Japan Steel Works, Ltd.

Toshiba Corporation

Yoichi Tsuda

Takashi Sasaki

Masayuki Yamada

Ryuichi Ishii

Takeo Takahashi

Katsuya Yamashita

Tsukasa Azuma

Nobuo Okita

Yukio Shinozaki

Seiko Takahashi

Kenichi Imai

Yasuhiko Tanaka

Kenji Kamimura

Masafumi Fukuda

Toru Takahashi

Yomei Yoshioka

Takao Inukai

Masataka Kikuchi

Satoru Asai

Eiji Maeda

Ryou Oda

Joji Kaneko

Yasumi Ikeda

An intermediate-pressure turbine is divided into a high-temperature, high-pressure side high-temperature, intermediate-pressure turbine sectionand a low-temperature, low-pressure side low-temperature, intermediate-pressure turbine section, the component members of the high-temperature, intermediate-pressure turbine sectionare formed of austenitic heat-resistant steels or Ni-based alloys, and the high-temperature, intermediate-pressure turbine sectionis operated by steam having a temperature of 650&#xb0; C. or more. Other turbines are mainly formed of ferritic heat-resistant steels. Thus, a steam turbine power plant having high thermal efficiency and being economical can be provided.

Steam turbine power plant

A heat-resisting steel comprising 0.15-0.30 wt. % C, 0.05-0.3 wt. % Si, 0.01-0.7 wt. % Mn, 1.8-2.5 wt. % Cr, 0.15-0.23 wt. % V, 1.5-2.5 wt. % W, 0.01-0.02 wt. % Ti, 0.01-0.08 wt. % Nb, 0.005-0.03 wt. % N, 0.001-0.015 wt. % B, and Fe and unavoidable impurities as the remainder; a heat-resisting steel comprising 0.15-0.30 wt. % C, 0.05-0.3 wt. % Si, 0.01-0.7 wt. % Mn, 1.8-2.5 wt. % Cr, 0.15-0.23 wt. % V, 1.5-2.5 wt. % W, 0.3-0.8 wt. % Mo, 0.01-0.02 wt. % Ti, 0.01-0.08 wt. % Nb, 0.005-0.03 wt. % N, 0.001-0.015 wt. % B, and Fe and unavoidable impurities as the remainder; and a heat-resisting steel that is obtained by subjecting one of the above heat-resisting steels to a heat treatment comprising the step of oil-cooling the heat-resisting steel to a temperature of 300&deg; C. or lower. These heat-resisting steels are excellent in both high-temperature strength and impact properties.

Heat-resisting steel, method for thermally treating heat-resisting steel, and components made of heat-resisting steel

A steam turbine rotor having a combination of at least one of a high pressure rotor, an intermediate pressure rotor and a low pressure rotor, which are each formed from a metal material of different chemical composition and welded together by means of welding.

Steam turbine rotor and manufacturing method thereof

Disclosed is a heat resistant steel casting, comprising C, 0.15-0.3%, Si, 0.1-0.30%, Mn, 0.01-0.1%, Cr, 2.0-2.5%, Mo, 0.3-0.8%, V, 0.23-0.3%, W, 1.6-2.6%, N, 0.005-0.03%, B, 0.001-0.004%, impurity elements including Ni not larger than 0.2%, P not larger than 0.03% and S not larger than 0.01%, B equivalent determined by B&plus;0.5N given below being not larger than 0.02%, Mo equivalent determined by Mo&plus;0.5W given below falling within a range of between 1.4% and 2.0%, and C equivalent determined by C&plus;Mn/6&plus;Si/24&plus;Ni/40&plus;Cr/5&plus;Mo/14&plus;V/14 given below being not smaller than 0.65%, and balance of iron wherein a precipitated phase consisting of a M C carbide, a M C carbide, and MX carbonitride is a texture finely precipitated in a matrix phase, and a ratio of the precipitated phase to the matrix phase falls within a range of between 0.6% and 1.0%.

Heat resistant steel casting and method of manufacturing the same

A steam turbine includes a turbine high pressure section, a turbine intermediate pressure section and a turbine low pressure section, in which at least two or more of these pressure sections are combined together, and a turbine rotor which is subjected to a gradient thermal treatment at different thermal treating temperatures at respective pressure sections is rotatably supported by bearings and accommodated in a turbine casing, and in a case where an axial distance from a setting position of a turbine movable blade of a final stage of the turbine low pressure section to a setting position of a partition plate disposed at a time when the gradient thermal treatment is performed to each of the pressure sections at different thermal treating temperature is defined as A, a blade length of the turbine movable blade is defined as B, and an axial distance from a prior stage of the final stage of the turbine low pressure section to the setting position of the partition plate is defined as C, the setting position of the partition plate is set in a range of (A/B)&gE;0.9 and C&gE;300 mm.

Steam turbine

A high toughness heat-resistant steel, a turbine rotor formed of this steel and a method of producing the turbine rotor are described. The heat-resistant steel has a composition consisting essentially of: 0.05 to 0.30 wt % C, 0 to 0.20 wt % Si, 0 to 1.0 wt % Mn, 8.0 to 14.0 wt % Cr, 0.5 to 3.0 wt % Mo, 0.10 to 0.50 wt % V, 2.0 to 5.0 wt % Ni, 0.01 to 0.50 wt % Nb, 0.01 to 0.08 wt % N, 0.001 to 0.020 wt % B, balance Fe and unavoidable impurities. The steel has excellent characteristics in not only tensile strength and toughness at a relatively low temperature condition of a steam turbine such as high/low pressure combined type one but also creep rupture strength at a high temperature condition of this turbine.

High toughness heat-resistant steel, turbine rotor and method of producing the same

A rotor for steam turbine rotor made of a heat resistant steel having a composition, which contains 0.05 to 0.3% by weight of C, 8.0 to 13.0% by weight of Cr, 1.0% by weight or less (excluding 0%) of Si, 1.0% by weight or less (excluding 0%) of Mn, 2.0% by weight or less (excluding 0%) of Ni, 0.10 to 0.50% by weight of V, 0.50 to 5.0% by weight of W, 0.025 to 0.10% by weight of N, 1.5% by weight or less excluding 0%) of Mo, at least one element selected from the group consisting of 0.03 to 0.25% by weight of Nb and 0.03 to 0.50% by weight of Ta, 0 to 3% of Re, 0 to 5.0% by weight of Co, 0 to 0.05% by weight of B and the balance of Fe and inevitable impurities, and having a ferrite/martensite structure.

Rotor for steam turbine and manufacturing method thereof

A rotor forging composed of Cr--Mo--V type alloy based on iron is normalizing-treated at a temperature of from 1000 to 1150.degree. C., the temperature is maintained at 650.degree.-750.degree. C. on the way of cooling the temperature from the normalizing-treating temperature to pearlite transform the microstructure of the rotor forging, the portions of the rotor forging corresponding to a high pressure or middle pressure portion are quenched at 940.degree.-1020.degree. C. and the portion corresponding to the low pressure portion is quenched at 850.degree.-940.degree. C. after the heat treatment is carried out at 920.degree.-950.degree. C. once or more times, and the rotor forging is subjected to tempering at 550.degree.-700.degree. C. once or more times. A high creep strength at the high and middle pressure portions can be obtained and, at the same time, the toughness at the low pressure portion is drastically enhanced.

Process for producing high-and low-pressure integral-type turbine rotor

A high pressure-low pressure single cylinder turbine rotor is disclosed which is characterized by being formed of a steel of a composition having, by weight, a C content of from 0.10 to 0.35%, a Si (silicon) content of not more than 0.3% (not including 0%), a Mn (manganese) content of not more than 1.0% (not including 0%), a Ni content of from 1.0 to 2.0%, a Cr (chromium) content of from 1.5 to 3.0%, a Mo content of from 0.9 to 1.3%, a V (vanadium) content of from 0.10 to 0.35%, a Nb (niobium) content of from 0.01 to 0.15%, a W content of from 0.1 to 1.5%, and the balance of Fe (iron) and inevitable impurities, the inevitable impurities having a P content of not more than 0.005%, a S content of not more than 0.001%, an As content of not more than 0.008%, a Sb content of not more than 0.004%, and a Sn content of not more than 0.008%.

High pressure-low pressure single cylinder turbine rotor and method of

A heat resisting steels comprising, on percentage by weight basis, 0.05 to 0.2% of C, not more than 1.0% of Ni, 9 to 13% of Cr, 0.05 to 1% of Mo, 0.05 to 0.3% of V, 1 to 3% of W, 1 to 5% of Co, 0.01 to 0.1% of N, at least one member selected from 0.01 to 0.15% of Nb, 0.01 to 0.15% of Ta, 0.003 to 0.03% of a rare earth element, 0.003 to 0.03% of Ca and 0.003 to 0.03% of B, and the remainder of Fe and unavoidable impurities have enhanced high temperature characteristics and are suitable for use in parts of turbine such as turbine rotors, turbine blades, turbine disks and bolts.

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Tokyo, Japan

Yoichi Tsuda