Abstract: A steam turbine blade made of Ti-base alloy comprising an &agr;+&bgr; type phase in which a difference of a tensile strength is small between a blade portion and a dovetail portion, a tensile strength at a room temperature of the dovetail portion is equal to or more than 100 kg/mm2 and a suitable toughness is commonly provided together with a strength, as a steam turbine blade having a length of 43 inch or more, a method of manufacturing the same, a steam turbine power generating plant and a low pressure steam turbine.

Abstract: There is provided a steam turbine blade made of Ti-base alloy comprising an &agr;+&bgr; type phase in which a difference of a tensile strength is small between a blade portion and a dovetail portion, a tensile strength at a room temperature of the dovetail portion is equal to or more than 100 kg/mm2 and a suitable toughness is commonly provided together with a strength, as a steam turbine blade having a length of 43 inch or more, a method of manufacturing the same, a steam turbine power generating plant and a low pressure steam turbine.

Abstract: A steam turbine comprising a rotor shaft integrating high and low pressure portions provided with blades at the final stage thereof having a length not less than 30 inches, wherein a steam temperature at first stage blades is 530° C., a ratio (L/D) of a length (L) defined between bearings of the rotor shaft to a diameter (D) measured between the terminal ends of final stage blades is 1.4 to 2.3. This rotor shaft is composed of heat resisting steel containing by weight 0.15 to 0.4% C, not more than 0.1% Si, 0.05 to 0.25% Mn, 1.5 to 2.5% Ni, 0.8 to 2.5% Cr, 0.8 to 2.5% Mo and 0.15 to 0.35% V and, further, the heat resisting steel may contain at least one of Nb, Ta, W, Ti, Al, Zr, B, Ca, and rare earth elements.

Abstract: There is provided a steam turbine blade made of Ti-base alloy comprising an &agr;+&bgr; type phase in which a difference of a tensile strength is small between a blade portion and a dovetail portion, a tensile strength at a room temperature of the dovetail portion is equal to or more than 100 kg/mm2 and a suitable toughness is commonly provided together with a strength, as a steam turbine blade having a length of 43 inch or more, a method of manufacturing the same, a steam turbine power generating plant and a low pressure steam turbine.

Abstract: A steam turbine in which principal components to be exposed to high temperatures are all made of ferritic steel, whereby the temperatures of main steam and reheat steam can be increased to 610-660 (° C.). The rotor shaft (23 in FIG. 1) of the steam turbine is made of ferritic forged steel whose 100,000-hour creep rupture strength is at least 15 (kg/mm2) at the service temperature of the rotor shaft. Likewise, the casing (18) is made of ferritic cast steel whose 100,000-hour creep rupture strength is at least 10 (kg/mm2). The steam turbine of high thermal efficiency can be applied to a steam-turbine power plant.

Abstract: A steam turbine includes a rotor shaft, movable blades assembled on the rotor shaft, fixed blades for guiding inflow of steam to the moving blades, and an inner casing for holding the fixed blades. The rotor shaft and at least a first stage of the movable blades are made of high-strength martensitic steel comprising 0.05-0.20(%) of C, at most 0.15(%) of Si, 0.3-0.7(%) of Mn, 9.5-13(%) of Cr, 0.3-0.7(%) of Ni, 0.05-0.35(%) of V, 0.02-0.15(%) of Nb, 0.01-0.06(%) of N, 0.05-0.5(%) of Mo, 1.0-3.5(%) of W, 2-10(%) of Co and 0.0005-0.03(%) of B and at least 78(%) of Fe (the percentages being given in terms of weight). The inner casings is made of martensitic cast steel comprising 0.06-0.16(%) of C, at most 0.5(%) of Si, at most 1(%) of Mn, 0.2-1.0(%) of Ni, 8-12(%) of Cr, 0.05-0.35(%) of V, 0.01-0.15(%) of Nb, 0.01-0.1(%) of N, at most 1.5% of Mo, 1-4(%) of W and 0.0005-0.03(%) of B and at least 85(%) of Fe (the percentages being given in terms of weight).

Abstract: A steam turbine has main components such as rotor shaft exposed to high temperature and intermediate pressure, which are made of a ferritic steel and the main steam temperature and the re-heat steam temperature are 610.degree. C. to 660.degree. C., and a steam turbine power plant employs the turbine. Further, the rotating blades are made of only a martensitic steel or a combination of the martensitic steel and a Ni base alloy, the turbine rotor is made of a ferritic forged steel having a creep rupture strength at the operating temperature for 100 thousands hours of above 15 kg/mm.sup.2, and the casing is made of a ferritic cast steel having a creep rupture strength at the operating temperature for 100 thousands hours of above 10 kg/mm.sup.2.

Abstract: A steam turbine in which principal components to be exposed to high temperatures are all made of ferritic steel, whereby the temperatures of main steam and reheat steam can be increased to 610-660 (.degree.C.). The rotor shaft (23 in FIG. 1) of the steam turbine is made of ferritic forged steel whose 100,000-hour creep rupture strength is at least 15 (kg/mm.sup.2) at the service temperature of the rotor shaft. Likewise, the casing (18) is made of ferritic cast steel whose 100,000-hour creep rupture strength is at least 10 (kg/mm.sup.2). The steam turbine of high thermal efficiency can be applied to a steam-turbine power plant.

Abstract: The present invention relates to a steam turbine comprising a rotor shaft integrating high and low pressure portions provided with blades at the final stage thereof having a length not less than 30 inches, wherein a steam temperature at first stage blades is 530.degree. C., a ratio (L/D) of a length (L) defined between bearings of the rotor shaft to a diameter (D) measured between the terminal ends of final stage blades is 1.4 to 2.3. This rotor shaft is composed of heat resisting steel containing by weight 0.15 to 0.4 % C, not more than 0.1 % Si, 0.05 to 0.25 % Mn, 1.5 to 2.5 % Ni, 0.8 to 2.5 % Cr, 0.8 to 2.5 % Mo and 0.15 to 0.35 % V and, further, the heat resisting steel may contain at least one of Nb, Ta, W, Ti, Al, Zr, B, Ca, and rare earth elements.

Abstract: The present invention relates to a steam turbine comprising a rotor shaft integrating high and low pressure portions provided with blades at the final stage thereof having a length not less than 30 inches, wherein a steam temperature at first stage blades is 530.degree. C., a ratio (L/D) of a length (L) defined between bearings of the rotor shaft to a diameter (D) measured between the terminal ends of final stage blades is 1.4 to 2.3. This rotor shaft is composed of heat resisting steel containing by weight 0.15 to 0.4% C, not more than 0.1% Si, 0.05 to 0.25% Mn, 1.5 to 2.5% Ni, 0.8 to 2.5% Cr, 0.8 to 2.5% Mo and 0.15 to 0.35% V and, further, the heat resisting steel may contain at least one of Nb, Ta, W, Ti, Al, Zr, B, Ca, and rare earth elements.

Abstract: The present invention relates to a steam turbine comprising a rotor shaft integrating high and low pressure portions provided with blades at the final stage thereof having a length not less than 30 inches, wherein a steam temperature at first stage blades is 530.degree. C., a ratio (L/D) of a length (L) defined between bearings of the rotor shaft to a diameter (D) measured between the terminal ends of final stage blades is 1.4 to 2.3. This rotor shaft is composed of heat resisting steel containing by weight 0.15 to 0.4% C, not more than 0.1% Si, 0.05 to 0.25% Mn, 1.5 to 2.5% Ni, 0.8 to 2.5% Cr, 0.8 to 2.5% Mo and 0.15 to 0.35% V and, further, the heat resisting steel may contain at least one of Nb, Ta, W, Ti, Al, Zr, B, Ca, and rare earth elements.

Abstract: The present invention relates to a steam turbine comprising a rotor shaft integrating high and low pressure portions provided with blades at the final stage thereof having a length not less than 30 inches, wherein a steam temperature at first stage blades is 530.degree. C., a ratio (L/D) of a length (L) defined between bearings of the rotor shaft to a diameter (D) measured between the terminal ends of final stage blades is 1.4 to 2.3. This rotor shaft is composed of heat resisting steel containing by weight 0.15 to 0.4% C, not more than 0.1% Si, 0.05 to 0.25% Mn, 1.5 to 2.5% Ni, 0.8 to 2.5% Cr, 0.8 to 2.5% Mo and 0.15 to 0.35% V and, further, the heat resisting steel may contain at least one of Nb, Ta, W, Ti, Al, Zr, B, Ca, and rare earth elements.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.