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: A combined cycle power generation system in which a generator is driven by a steam turbine and a gas turbine includes a steam turbine rotor having a mono-block rotor shaft with blades mounted thereon in multi-stages from a high pressure side to a low pressure side and a casing covering the rotor. An inlet temperature of steam to first stage blades is not less than 530° C. and the rotor shaft is made of a Ni—Cr—Mo—V low alloy steel of bainitic structure having a higher creep rupture strength at the high pressure side than at the low pressure side and a 538° C. and 105 h creep rupture strength not less than 12 kg/mm2 at a central portion, and having mounted thereon at the central portion, first stage blades at the high pressure side or FATT of not more than 20° C.

Abstract: A compressor for a gas turbine, comprises a rotor including a plurality of rotor parts, and blades for a plurality of stages implanted in the rotor parts, the rotor part in which the blades for at least two of the stages are implanted is made of a Ni--Cr--Mo--V low alloy steel, and the Ni--Cr--Mo--V low alloy steel has substantially an entire bainite microstructure comprising, in weight percent, C of 0.15-0.40%, Si not more than 0.1%, Mn not more than 0.5%, Ni of 1.5-2.5%, Cr of 0.8-2.5%, Mo of 0.8-2.0%, V of 0.1-0.35% and the balance being substantially Fe.

Abstract: A high and low pressure sides integrating steam turbine having high and low pressure sides integrating steam turbine blades, each made of a martensite steel including 8-13 wt % Cr, and having a blade length of 33 inches or more for 60 Hz power generation and 40 inches for 50 Hz power generation.

Abstract: A compressor for a gas turbine, comprises a rotor including a plurality of rotor parts, and blades for a plurality of stages, e.g., twelve stages, implanted in the rotor parts, the rotor part in which the blades for at least two of the stages are implanted is made of a Ni--Cr--Mo--V low alloy steel, and the Ni--Cr--Mo--V low alloy steel has substantially an entire bainite microstructure comprising, in weight percent, C of 0.15-0.40%, Si not more than 0.1%, Mn not more than 0.5%, Ni of 1.5-2.5%, Cr of 0.8-2.5%, Mo of 0.8-2.0%, V of 0.1-0.35% and the balance being substantially Fe. Blades for at least two of the stages are implanted in one of the rotor parts.

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: New low-alloy steel compositions and rotor shafts for electric machines made from them are described. High nickel and chromium contents ensure high strength and toughness, while other components, notably silicon and other impurities, are kept low with the result that magnetic properties remain good. One aspect provides a steel with the following proportions by weight:______________________________________ C 0.15 to 0.3% Si <0.1% Mn <1% Ni 3 to 5% Cr >2%, <3.5% (Mo + W) 0.1 to 1.0%, W being optional V 0.03 to 0.35%, ______________________________________and the remainder substantially Fe.Other aspects are also described.

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: New low-alloy steel compositions and rotor shafts for electric machines made from them are described. High nickel and chromium contents ensure high strength and toughness, while other components, notably silicon and other impurities, are kept low with the result that magnetic properties remain good. One aspect provides a steel with the following proportions by weight:C 0.15 to 0.3%Si <0.1%Mn <1%Ni 3 to 5%Cr >2%, <3.5%(Mo+W) 0.1 to 1.0%, W being optionalV 0.03 to 0.35%,and the remainder substantially Fe.Other aspects are also described.

Abstract: A high-temperature gas turbine includes a compressor, and a turbine coupled to the compressor, the turbine being capable of rotating at a high speed by a gas of firing temperature generated by a combustor. The compressor includes a combined type rotor shaft and blades of at least 15 stages which are implanted in the combined type rotor shaft. The compressor compresses air to a temperature of 400.degree. C. or above. The combined type rotor shaft is made of Ni--Cr--Mo--V low alloy steel having all bainitic microstructure whose composition consists, as analyzed in weight percent, of 0.15-0.40% C, 0.1% or less Si, 0.5% or less Mn, 1.5-2.5% Ni, 0.8-2.5% Cr, 0.8-2.0% Mo, 0.1-0.35% V and the balance substantially of Fe.

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 high-temperature gas turbine includes a compressor, and a turbine coupled to the compressor, the turbine being capable of rotating at a high speed by a gas of firing temperature generated by a combustor. The compressor includes a combined type rotor shaft and blades of at least 15 stages which are implanted in the combined type rotor shaft. The compressor compresses air to a temperature of 400.degree. C. or above. The combined type rotor shaft is made of Ni--Cr--Mo--V low alloy steel having all bainitic microstructure whose composition consists, as analyzed in weight percent, of 0.15-0.40% C, 0.1% or less Si, 0.5% or less Mn, 1.5-2.5% Ni, 0.8-2.5% Cr, 0.8-2.0% Mo, 0.1-0.35% V and the balance substantially of Fe.

Abstract: New low-alloy steel compositions and rotor shafts for electric machines made from them are described. High nickel and chromium contents ensure high strength and toughness, while other components, notably silicon and other impurities, are kept low with the result that magnetic properties remain good. One aspect provides a steel with the following proportions by weight:C 0.15 to 0.3%Si <0.1%Mn <1%Ni 3 to 5%Cr >2%, <3.5%(Mo+W) 0.1 to 1.0%, W being optionalV 0.03 to 0.35%,and the remainder substantially Fe.Other aspects are also described.

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 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.

Abstract: 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.

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.