JP5389763B2 - Rotor shaft for steam turbine, steam turbine and steam turbine power plant using the same - Google Patents

Description

  The present invention relates to a steam turbine rotor shaft, a high-pressure, medium-pressure, and high-medium-pressure integrated steam turbine using the same, and a steam turbine power plant using the same, and more particularly, steam turbine power generation used in an ultra-supercritical pressure power plant. It relates to the plant.

  In recent years, high-temperature and high-pressure has attracted attention from the viewpoint of improving the efficiency of thermal power plants, and the steam temperature of steam turbines is currently targeted at 600 ° C., and ultimately 650 ° C. In order to increase the steam temperature, a heat-resistant material having higher high-temperature strength than the conventionally used ferritic heat-resistant steel is required as a material constituting the turbine. For example, some austenitic heat-resistant alloys have excellent high-temperature strength, but there is a problem that thermal fatigue strength is inferior due to a large coefficient of thermal expansion.

  For this reason, Patent Document 1, Patent Document 2 and Patent Document 3 are examples of new ferritic heat resistant steels with improved high-temperature strength. Moreover, patent document 4 and patent document 5 are known as a steam turbine power plant.

JP-A-4-147948 JP-A-9-296258 Japanese Patent Publication No.8-30249 JP-A-7-233704 Japanese Patent Laid-Open No. 11-93603

  However, since the alloys proposed in Patent Documents 1 to 5 contain a large amount of W and Co, they form brittle intermetallic compounds on the long time side, and also contain Ni, so that they have a dislocation strengthened structure. The high temperature strength is still insufficient to achieve the ultimate vapor temperature of 650 ° C. Therefore, it has been desired to develop a ferritic heat-resistant steel having high high-temperature strength and stable strength even when used for a long time.

  Therefore, the present invention provides a steam turbine rotor shaft that is excellent in high temperature and long-side strength at a specific temperature of 600 ° C. or more and 50,000 hours or more and a long-time side, and a high-pressure, medium-pressure, and high-medium-pressure integrated type using the same. An object is to provide a steam turbine and a steam turbine power plant.

  In order to solve the above-mentioned problems, the present invention is, by mass, C 0.06-0.13%, Si 0.15% or less, Mn 0.1-1.0%, Ni 0.005-0.1%, Cr 8.5. ~ 10.0%, Mo 0.05 ~ 0.50%, W 1.0 ~ 3.0%, V 0.05 ~ 0.30%, Nb 0.02 ~ 0.10%, Co 0.5 ~ 2.5% , N 0.005-0.035%, B 0.001-0.030% and Al 0.0005-0.006%, (5 × Ni + Mo) is 0.3-0.9%, (100 × C + Cr) Is made of martensitic steel consisting of 15.5 to 20.5% and the balance being Fe and inevitable impurities.

Moreover, this invention is C0.06-0.13% by mass, Si0.15% or less, Mn0.1-1.0%, Ni0.005-0.1%, Cr8.5-10.0%, Mo 0.05 to 0.50%, W 1.0 to 3.0%, V 0.05 to 0.30%, Nb 0.02 to 0.10%, Co 0.5 to 2.5%, N 0.005 to 0 0.035%, B0.001-0.030% and Al 0.0005-0.006%, (5 × Ni + Mo) 0.3-0.9%, (100 × C + Cr) 15.5-20 .5%, is composed of a martensitic steel balance being Fe and unavoidable impurities, 650 ° C., 10 ⁵ h creep rupture strength is a steam turbine rotor shaft, characterized in that it is 98 N / mm ² or more.

  The present invention also provides a steam turbine comprising: a rotor shaft; a moving blade implanted in the rotor shaft; a stationary blade that guides the inflow of steam into the moving blade; and an inner casing that holds the stationary blade. The rotor blade has at least five stages on one side and the first stage is a double-flow high-pressure turbine. The rotor blade has six stages or more symmetrically and the first stage is implanted in the center of the rotor shaft. A medium pressure turbine having a double flow structure, a high pressure turbine section in which six or more stages of the moving blades are implanted and high temperature and high pressure steam generated by a steam generator flows from a central portion of the rotor shaft, and the moving blades Are combined with a tandem in which the intermediate pressure side turbine portion into which steam exhausted from the high pressure side turbine portion and heated by the reheater flows from the central portion of the rotor shaft is connected in tandem T At least one of the bottles. And the said rotor shaft is the rotor shaft for steam turbines of an above described composition, or C0.06-0.13% by weight, Preferably it is 0.07-0.12%, More preferably, it is 0.07-0. 09%, Si 0.15% or less, preferably 0.10% or less, Mn 0.1 to 1.0%, preferably 0.2 to 0.8%, more preferably 0.3 to 0.6%, Ni0 0.005 to 0.1%, preferably 0.01 to 0.1%, more preferably 0.02 to 0.1%, Cr 8.5 to 10.0%, preferably 8.8 to 10.0% , More preferably 9.0 to 9.8%, Mo 0.05 to 0.50%, preferably 0.10 to 0.45%, more preferably 0.20 to 0.40%, W 1.0 to 3 0.0%, preferably 1.5-2.8%, more preferably 1.8-2.5%, V0.05 0.3%, preferably 0.10-0.30%, Nb 0.02-0.10%, preferably 0.03-0.09%, more preferably 0.03-0.07%, Co0. 5-2.5%, preferably 1.0-2.5%, more preferably 1.5-2.5%, N 0.005-0.035%, preferably 0.006-0.03%, More preferably 0.01 to 0.02%, B 0.001 to 0.030%, preferably 0.003 to 0.02%, more preferably 0.005 to 0.01%, and Al 0.0005 to 0 It is characterized by being a steam turbine rotor shaft composed of a specific martensitic steel containing 0.006%, preferably 0.0008-0.005%, more preferably 0.001-0.004%.

C (carbon) is an indispensable element for ensuring hardenability and precipitating M ₂₃ C ₆ type carbides in the tempering process to increase the high temperature strength, and at least 0.06% is required. If it exceeds 0.13%, M ₂₃ C ₆ type carbide is excessively precipitated, and the matrix strength is lowered, and the high temperature strength on the long time side is impaired, so the content is limited to 0.06 to 0.13%. Preferably, it is 0.07 to 0.12%, more preferably 0.07 to 0.09%.

  Si (silicon) promotes the formation of a Laves phase and lowers the ductility due to grain boundary segregation or the like, so it is limited to 0.15% or less. Preferably, it is 0.10% or less. However, when Si is added in a very small amount of 0.03% or more as a deoxidizer, good high temperature characteristics can be obtained from the relationship with Al deoxidation described later.

Mn (manganese) is required to be at least 0.1% as an element that suppresses the formation of δ ferrite and promotes the precipitation of M ₂₃ C ₆ type carbide, but if it exceeds 1.0%, the oxidation resistance deteriorates. Therefore, it is limited to 0.1 to 1.0%. Preferably, it is 0.2 to 0.8%, and more preferably 0.3 to 0.6%.

  Ni (nickel) is an important element that distinguishes and characterizes the present invention from the conventional invention. Ni is an element that suppresses the formation of δ ferrite and imparts toughness, and at least 0.005% is necessary, but the value of the relational expression (5 × Ni + Mo) represented by Ni and Mo is 0.3 to In a specific relationship of 0.9%, it can be contained 0.1% or less, and in order to improve long-term creep rupture strength by the interaction between Ni and Mo, it is limited to 0.005 to 0.1%. Preferably it is 0.01 to 0.1%, More preferably, it is 0.02 to 0.1%.

Cr (chromium) imparts oxidation resistance and is an indispensable element for increasing the high temperature strength by precipitating M ₂₃ C ₆ type carbide, and a minimum of 8.5% is necessary. In the specific relationship where the value of the relational expression (100 × C + Cr) is 15.5 to 20.5%, it can contain 10% or less in order to stabilize the structure in the long-term creep strength and increase the strength. 8.5 to 10.0%. Preferably, it is 8.8 to 10.0%, more preferably 9.0 to 9.8%.

Mo (molybdenum) promotes the fine precipitation of M ₂₃ C ₆ type carbide and has the effect of hindering the coagulation. Therefore, it is effective for maintaining high temperature strength for a long time, and at least 0.05% is necessary. When it is 50% or more, a Laves phase is easily generated, so the content is limited to 0.05 to 0.50%. Preferably, it is 0.10 to 0.45%, more preferably 0.2 to 0.4%.

W (tungsten) has a stronger action of suppressing the aggregation and coarsening of M ₂₃ C ₆ type carbide than Mo, and is effective in improving the high-temperature strength because it strengthens the matrix by solid solution, and at least 1.0% is required. However, if it exceeds 3.0%, δ ferrite and Laves phase are likely to be formed, and conversely, the high temperature strength is lowered, so the content is limited to 1.0 to 3.0%. Preferably, it is 1.5 to 2.8%, more preferably 1.8 to 2.5%.

V (vanadium) is effective in precipitating the carbonitride of V to increase the high temperature strength, and requires a minimum of 0.05%, but if it exceeds 0.3%, the carbon is excessively fixed, Since the amount of precipitation of M ₂₃ C ₆ type carbide is reduced and the high temperature strength is lowered, the content is limited to 0.05 to 0.3%. Preferably, it is 0.10 to 0.30%.

At least one of Nb (niobium) and Ta (tantalum) helps to make NbC and TaC finer, and partly dissolves during quenching to precipitate NbC and TaC during the tempering process. In addition, there is an effect of increasing the high-temperature strength, and at least 0.02% is necessary. However, if it exceeds 0.10%, the carbon is excessively fixed in the same manner as V, and the precipitation amount of M ₂₃ C ₆ type carbide is reduced. Since it reduces the high temperature strength, it is limited to 0.02 to 0.10%. Preferably, it is 0.03 to 0.09%, more preferably 0.03 to 0.07%.

  Co (cobalt) is effective in suppressing δ ferrite and increasing the high temperature strength by solid solution strengthening, and at least 0.5% is necessary, but when it exceeds 2.5%, the formation of Laves phase is promoted. In order to destabilize the tissue and lower the high temperature strength, the content is limited to 0.5 to 2.5%. Preferably, it is 1.0 to 2.5%, more preferably 1.5 to 2.5%.

  N (Nitrogen) precipitates V nitride, and in the state of solid solution, jointly works with Mo and W to increase high temperature strength by IS effect (interaction between interstitial solid solution element and substitution solid solution element). At least 0.005% is necessary, but if it exceeds 0.035%, BN is formed by the interaction with B, and the addition effect of N and B cannot be obtained and the high temperature strength is lowered. Therefore, it is limited to 0.005 to 0.035%. Preferably, it is 0.006 to 0.03%, more preferably 0.01 to 0.02%.

  Al (aluminum) is added in an amount of 0.0005% or more as a deoxidizer and a grain refiner. However, Al is a strong nitride-forming element. By fixing nitrogen that works effectively for creep, especially when exceeding 0.006%, long-term creep strength of 50,000 hours or more in a high temperature range of 625 to 700 ° C. Has the effect of lowering. Further, Al promotes the precipitation of the Laves phase, which is a brittle intermetallic compound mainly composed of W, invites the precipitation to the crystal grain boundary, and lowers the creep rupture strength on the long time side. In particular, in the case of extreme grain refinement, Laves phase continuously precipitates at the grain boundaries. Therefore, the upper limit is made 0.006%. Preferably, it is 0.0008 to 0.005%, more preferably 0.001 to 0.004%.

B (boron) is a solid solution in the grain boundary strengthening effect and _M 23 _{C 6,} has the effect of enhancing the high temperature strength by the action preventing the aggregation and coarsening of _M 23 _{C 6} type carbide, effective when added Minimum 0.001% However, if it exceeds 0.030%, weldability and forgeability are impaired, so the content is limited to 0.001 to 0.030%. Preferably, it is 0.003 to 0.02%, more preferably 0.005 to 0.01%.

Further, the chromium equivalent (Cr equivalent) obtained by the following formula 1 is preferably 4 to 10, and particularly preferably 6.5 to 9.5.
Cr equivalent = -40C (%)-30N (%)-2Mn (%)-4Ni (%) + Cr (%) + 6Si (%) + 4Mo (%) + 1.5 W (%) + 11 V (%) + 5 Nb (%) + 2 .5Ta (%)-2Co (%) Formula 1
The steam turbine rotor shaft according to the present invention is obtained by casting an ingot by vacuum melting, vacuum C deoxidation, ESR melting, forging, heating at 900 to 1150 ° C., and 50 to 600 ° C. / h Quenching by cooling, followed by primary tempering at 500-620 ° C. and secondary tempering at 600-750 ° C. at higher temperatures.

  The steam turbine power plant according to the present invention includes a high-pressure turbine, an intermediate-pressure turbine, and one or two low-pressure turbines connected in tandem or cross, or a high-pressure turbine, a low-pressure turbine, a generator, In a steam turbine power plant in which a pressure turbine, a low-pressure turbine, and a generator are all connected in tandem, the high-pressure turbine and the intermediate-pressure turbine are respectively composed of the high-pressure turbine and the intermediate-pressure turbine described above, and the rotor shaft thereof is It consists of the rotor shaft for steam turbines.

Next, a schematic configuration of the steam turbine power plant according to the present invention will be described.
In the steam turbine power plant according to the present invention, the steam inlet temperature to the first stage blades is 593 to 660 ° C. (593 to 605 ° C., 610 to 620 ° C., 620 ° C.). 630 ° C. and 630 to 640 ° C. are preferable, and the pressure is 24.5 MPa (250 kgf / cm ² ) or more (preferably 24.1 to 31.0 MPa (246 to 316 kgf / cm ² )) or 16.7 to a 19.6MPa (170~200kgf / cm ^2), at least the first stage of the rotor shaft or rotor shaft and blades and vanes found 10 ⁵ hours creep rupture strength at a temperature corresponding to each steam temperature 98N / mm ² or more Cr8.5～10.0% mentioned above (preferably 160 N / mm ² or more) (preferably, 8. 10.0%, high-strength martensitic steel preferably has a fully tempered martensite structure containing more preferably from 9.0 to 9.8%). Furthermore, it is preferable that the first stage, the second stage, or the third stage of the moving blade is made of a Ni-based alloy. The low-pressure turbine preferably has a steam inlet temperature to the first stage blade of 350 to 400 ° C.

  Below, the preferable structure of the steam turbine which comprises the steam turbine power generation plant which concerns on this invention is shown.

  (1) The high-pressure turbine according to the present invention has 7 or more blades, preferably 9 or more, more preferably 9 to 12 blades, and the first-stage blade is a double flow, and a rotor shaft for a high-pressure turbine (hereinafter referred to as “rotor shaft”). The bearing center distance (L) is preferably 5000 mm or more (preferably 5100 to 6500 mm). The length of the blade is preferably 25 to 180 mm from the first stage moving blade to the last stage.

  (2) The intermediate pressure turbine according to the present invention has 6 or more, preferably 6 to 9 stages each of the rotor blades symmetrically in a side view along the longitudinal direction of the rotor shaft. It is a double flow structure in which a first stage rotor blade is implanted at the center of a rotor shaft (hereinafter sometimes referred to as an intermediate pressure rotor shaft), and the intermediate pressure rotor shaft has a bearing center distance (L) of 5000 mm or more (preferably 5100 to 6500 mm) is preferable. The length of the wing is preferably 60 to 300 mm.

  (3) The high and medium pressure integrated turbine according to the present invention has 7 or more, preferably 8 or more blades of the high-pressure side turbine section, and 5 or more, preferably 5 or more blades of the intermediate pressure side turbine section. It is preferable to have six or more stages. Further, the rotor shaft of the high-medium pressure integrated turbine (hereinafter sometimes referred to as a high-medium pressure rotor shaft) preferably has a bearing center distance (L) of 6000 mm or more (preferably 6100 to 7000 mm). Furthermore, the length of the wing portion is preferably 25 to 200 mm for the high pressure side turbine portion and 100 to 350 mm for the intermediate pressure side turbine portion.

  (4) The high-pressure rotor shaft, medium-pressure rotor shaft and high-medium-pressure rotor shaft according to the present invention, as a fully tempered martensite structure having the above-described composition, in order to obtain high high temperature strength and low temperature toughness and high fatigue strength, It is preferable that the Cr equivalent represented by Formula 1 is adjusted to 6.5 to 9.5.

  (5) The high-pressure rotor shaft, medium-pressure rotor shaft, and high-medium-pressure rotor shaft according to the present invention preferably form a built-up weld layer of Cr—Mo low alloy steel with high bearing characteristics in the journal portion, Preferably, the build-up weld layer having any number of layers from 3 to 10 is formed, and the amount of Cr in the weld material from the first layer to any of the second to fourth layers is sequentially reduced. And thereafter, welding is performed using a welding material made of steel having the same Cr amount, and the Cr amount of the welding material used for welding the first layer is about 2 to 6% by mass less than the Cr amount of the base material. And the Cr amount of the weld layer after that is 0.5 to 3% by mass (preferably 1 to 2.5% by mass).

  In order to improve the bearing characteristics of the journal part, overlay welding is preferable in terms of the highest safety, but a sleeve made of a low alloy steel having a Cr content of 1 to 3% is fitted and fitted. You can also

  Three or more layers are preferable for increasing the number of weld layers and gradually reducing the Cr content, and even if ten or more layers are welded, no further effect can be obtained. As an example, a final finish requires a thickness of about 18 mm. In order to form such a thickness, at least five overlay weld layers are preferable except for a final finishing allowance by cutting. It is preferable that the third and subsequent layers mainly have a tempered bainite structure and have carbides precipitated. In particular, the composition of the weld layer after the fourth layer is C0.01 to 0.1%, Si 0.3 to 1%, Mn 0.3 to 1.5%, Cr 0.5 to 3%, Mo0.1. Those containing ~ 1.5% and the balance being Fe are preferred.

  (6) Inner casing adjustable valve valve box, combined reheat valve valve box, main steam reed pipe, main steam inlet pipe, reheat inlet pipe, high pressure turbine of high pressure turbine, intermediate pressure turbine and high / medium pressure integrated turbine according to the present invention The nozzle box, the intermediate pressure turbine first stage diaphragm, the high pressure turbine main steam inlet flange, the elbow, and the main steam stop valve are preferably composed of the martensitic heat resistant steel described above.

24.5MPa (250kgf / cm ²⁾ or more ultra supercritical pressure turbine high pressure, the medium-pressure or intermediate-pressure internal casing and the main steam stop valve and governor valve casing, 10 ⁵ h creep rupture strength 88N for the operating temperature / mm ² or more and room temperature impact absorption energy of 9.8 J or more are preferable.

(7) the high-pressure turbine according to the present invention, the inner casing material of the intermediate-pressure turbine and the high and intermediate pressure integral turbine, the 10 ⁵ h creep rupture strength at a temperature corresponding to each steam temperature 68N / mm ² or more (preferably 78 N / mm ² or more), which is composed of martensitic cast steel containing 8 to 12% by mass of Cr. The specific composition is C0.06-0.16% (preferably 0.09-0.14%), N0.01-0.1% (preferably 0.02-0.06%) by mass. , Mn 1% or less (preferably 0.4 to 0.7%), Si added or 0.5% or less (preferably 0.1 to 0.4%), V 0.05 to 0.35% (preferably 0.15-0.25%), Nb 0.15% or less (preferably 0.02-0.1%), Ni 0.2-1% (preferably 0.4-0.8%), Cr8-12 % (Preferably 8 to 10%, more preferably 8.5 to 9.5%), W 1 to 3.5%, Mo 1.5% or less (preferably 0.4 to 0.8%) and the balance Fe The martensitic cast steel is preferred. The amount of W is 1.0 to 1.5% at 620 ° C, 1.6 to 2.0% at 630 ° C, 2.1 to 2.5% at 640 ° C, and 2.6 to 650 ° C. At 3.0% and 660 ° C., 3.1 to 3.5% is preferable.

  Addition of Ta, Ti and Zr has an effect of increasing toughness, and a sufficient effect can be obtained by adding Ta or less, Ta 0.1% or less and Zr 0.1% or less alone or in combination. When Ta is added in an amount of 0.1% or more, the addition of Nb can be omitted.

(8) The low-pressure turbine according to the present invention has a rotational speed of 3000 rpm or 3600 rpm, and the moving blades implanted in the rotor shaft are each five or more stages symmetrically in a side view centered on the steam inlet, preferably each 6 stages or more, more preferably 8-10 stages each, and a double flow structure in which the first stage rotor blades are implanted in the center of the rotor shaft. The rotor shaft has a bearing center distance (L) of 6500 mm or more (preferably 6600-7500 mm) is preferable. The length of the blade is preferably 90 mm or more for the first stage blade. Rotor shaft, said 0.02% yield strength at room temperature of the rotor shaft within the central portion is ^{784N / mm 2 (80kgf / mm} 2) or more, 0.2% proof stress ^{858N / mm 2 (87.5kgf / mm} 2) or more Or bainite steel having a tensile strength of 902 N / mm ² (92 kgf / mm ² ) or more and a FATT (brittle ductile transition temperature) of −5 ° C. or less or a 20 ° C. V-notch impact value of 98 J / cm ² or more. It is preferable.

  The final stage blade of the low-pressure turbine is made of Ti-base alloy, 17-4PH steel, 12% Cr martensite steel, and has high tensile strength to withstand high centrifugal force and vibration stress due to high-speed rotation. High cycle fatigue strength should be high. The Ti-based alloy contains 3 to 8% Al and 3 to 6% V, and is subjected to an aging treatment. Further, the latter 12% Cr martensitic steel significantly reduces fatigue strength when harmful δ ferrite is present. Therefore, the Cr equivalent represented by the above-described formula 1 having a fully tempered martensite structure is 10 or less, preferably Is adjusted to 4 to 10 and is substantially free of δ ferrite phase, and as a tempering heat treatment, it is preferably 1000 to 1100 ° C. (preferably 1000 to 1055 ° C.) after melting and forging. Is quenched for 0.5 to 3 hours and then rapidly cooled to room temperature (especially oil quenching is preferred), then tempered at 540 to 620 ° C., particularly preferably at 540 to 570 ° C. for 1 to 6 hours Two or more tempering heat treatments are performed: primary tempering to cool to room temperature and secondary tempering to cool to room temperature after holding at 560 to 590 ° C. for 1 to 6 hours. Preferably it is done. The secondary tempering temperature is preferably higher than the primary tempering temperature, particularly preferably 10 to 30 ° C, more preferably 15 to 20 ° C. Further, it is preferable to carry out a deep cooling process for cooling to dry ice or liquid nitrogen temperature in order to decompose the retained austenite more completely.

In particular, as a 12% Cr martensitic steel, C 0.14 to 0.40%, preferably 0.19 to 0.40%, Si 0.5% or less, Mn 1.5% or less, Ni 2 to 3.5%, Including one or more of Cr 8-13%, Mo 1.5-4%, Nb and Ta in total 0.02-0.3%, V 0.05-0.35% and N 0.04-0.15% Those are preferred.
Furthermore, the combination containing C0.20-0.40% and Mo1.5-3.5% or C0.14-0.19% and Mo2.0-3.5% is more preferable.

  The blade length of the last stage of the low-pressure turbine is 909.3 mm (35.8 inches), 952.5 mm (37.5 inches), 1016.0 mm (40 inches), 1066.8 mm (3600 rpm) For 42 inches and 3000 rpm, those of 1092.2 mm (43 inches), 1168.4 mm (46 inches), 1219.2 mm (48 inches) and 1270.0 mm (50 inches) apply.

  Further, it is preferable that an erosion prevention layer made of a Co-based alloy is provided at the leading edge portion of the tip of the last stage blade. It is preferable that the Co-base alloy is joined by electron beam or TIG welding to a plate material having Cr of 25 to 30%, W of 1.5 to 7.0%, and C of 0.5 to 1.5%.

  The last stage blade of the low-pressure turbine has an inclination in the width direction of the blade portion, the vicinity of the implanted portion is substantially parallel to the axial direction of the rotating shaft, and the blade tip is preferably inclined by 65 to 85 degrees with respect to the axial direction. An inclination of 70 to 80 degrees is more preferable. The length of the wings is 1092.2 mm (43 inches) or more for 3000 rpm or 952.5 mm (37.5 inches) or more for 3600 rpm, and the number of implantation parts is 1092.2 mm (43 inches) or more. It is preferable that it is a fork type which is 7 or more for the above and 952.5 mm (37.5 inches) or more or an inverted Christmas tree type having four or more steps. It is preferable that the implantation part width | variety is 2.1 to 2.5 times with respect to the width | variety of the said wing | blade part front-end | tip. An erosion prevention shield part is provided on the leading side of the tip of the wing part, the implantation part is a fork type, and a plurality of pin insertion holes for fixing to the rotor shaft are provided, and the diameter of the insertion hole is on the wing part side. It is preferably larger than the opposite side.

(9) The rotor shaft of the low-pressure turbine (hereinafter sometimes referred to as a low-pressure rotor shaft) is C0.2 to 0.3%, Si 0.15% or less, Mn 0.25% or less, Ni 3.25 to 4 Low alloy steel having 0.5%, Cr 1.6-2.5%, Mo 0.25-0.6%, V 0.05-0.25%, and having a total tempered bainite structure of Fe 92.5% or more. Preferably, it is manufactured by the same manufacturing method as the above-described high-pressure rotor shaft and medium-pressure rotor shaft. In particular, the amount of Si was 0.05% or less, Mn was 0.1% or less, and impurities such as P (phosphorus), S (sulfur), As (arsenic), Sb (antimony), Sn (tin) were reduced as much as possible. It is preferable to use a raw material and make it a super-clean production using a raw material with less impurities, so that the total amount is 0.025% or less, preferably 0.015% or less. P and S are each preferably 0.010% or less, Sn and As each 0.005% or less, and Sb 0.001% or less.
The low-pressure rotor shaft has 0.02% yield strength at room temperature of 784 N / mm ² (80 kgf / mm ² ) or more and 0.2% yield strength of 858 N / mm ² (87.5 kgf / mm ² ) or more at the center. A bainite steel having a strength of 902 N / mm ² (92 kgf / mm ² ) or more and a FATT of −5 ° C. or less or a 20 ° C. V notch impact value of 98 J / cm ² or more is preferable. The low-pressure rotor shaft according to the present invention is preferably provided with a fork-type rotor blade for the last stage blades having a center hole, and an inverted Christmas tree type for those having no center hole.

  (10) C 0.05 to 0.2%, Si 0.1 to 0.5%, Mn 0.2 to 1.0%, Cr 10 to 13%, except for the final stage of the moving blade for low pressure turbine All-tempered martensitic steel with Mo 0.04-0.2% is preferred.

  (11) Carbon cast steel having C0.2 to 0.3%, Si 0.3 to 0.7%, and Mn 1% or less is preferable for both the inner and outer casings for the low pressure turbine.

  (12) The main steam stop valve casing and the steam control valve casing are C 0.1 to 0.2%, Si 0.1 to 0.4%, Mn 0.2 to 1.0%, Cr 8.5 to 10.5%, Mo 0.3-1.0%, W 1.0-3.0%, V 0.1-0.3%, Nb 0.03-0.1%, N 0.03-0.08%, B0.0005-0 All tempered martensitic forged steel containing 0.003% is preferred.

  (13) The outer casings of the high-pressure turbine, the intermediate-pressure turbine, and the high- and intermediate-pressure integrated turbine have C0.10 to 0.20%, Si 0.05 to 0.6%, Mn 0.1 to 1.0%, Ni0. 1 to 0.5%, Cr 1 to 2.5%, Mo 0.5 to 1.5%, V 0.1 to 0.35%, preferably Al 0.025% or less, B0.0005 to 0.004% And it is preferable to manufacture with the cast steel which contains at least one of Ti0.05-0.2%, and has the whole tempered bainite structure. In particular, C0.10 to 0.18%, Si0.20 to 0.60%, Mn0.20 to 0.50%, Ni0.1 to 0.5%, Cr1.0 to 1.5%, Mo0.9 Cast steel containing ˜1.2%, V0.2˜0.3%, Al0.001˜0.005%, Ti0.045˜0.10% and B0.0005˜0.0020% is preferable. More preferably, the Ti / Al ratio is 0.5-10.

  (14) High-pressure, medium-pressure, high-medium-pressure integrated steam turbine (high-pressure side turbine section and medium-pressure side turbine section) first stage rotor blades at steam temperatures of 610 to 650 ° C., preferably high-pressure turbine and high-medium-pressure integrated turbine high pressure The side turbine section is up to 2 or 3 stages, and the intermediate pressure turbine section of the intermediate pressure turbine and the high and intermediate pressure integrated turbine is up to 2 stages in mass, instead of the martensitic steel described above, C0.03 to 0.20% ( Preferably 0.03 to 0.15%), Cr 12 to 20%, Mo 9 to 20% (preferably 12 to 20%), Co 12% or less (preferably 5 to 12%), Al 0.5 to 1.5% , Ti 1 to 3%, Fe 5% or less, Si 0.3% or less, Mn 0.2% or less, B 0.003 to 0.015%, Mg 0.1% or less, rare earth element 0.5% or less, Zr 0.5 1% or less It may be used Ni-base alloy. The following content of each element includes 0%. The Ni-based alloy is subjected to solution treatment and aging treatment after melt forging.

  According to the present invention, it is possible to obtain a steam turbine rotor shaft excellent in high-temperature and long-side strength at a specific temperature of 600 ° C. or more and 50,000 hours or more and a long-time side. When used for a body-type turbine, particularly when applied to an ultra-supercritical steam turbine, the steam temperature of the steam turbine can be increased to 650 ° C. or more, and a remarkable effect is obtained in improving the thermal efficiency of the steam turbine power plant.

It is a block diagram of the steam turbine power plant in 1st Embodiment. It is sectional drawing which shows the structure of the high pressure turbine couple | bonded with the tandem, and an intermediate pressure turbine. It is sectional drawing which shows the structure of a low pressure turbine. It is a block diagram of the steam turbine power plant in 2nd Embodiment. It is sectional drawing which shows the structure of a high and medium pressure integrated turbine. It is sectional drawing which shows the structure of the low pressure turbine in 2nd Embodiment.

(Manufacturing method of rotor shaft for steam turbine)
The material for the rotor shaft of the steam turbine rotor shaft (hereinafter simply referred to as the rotor shaft) of the steam turbine provided in the steam turbine power plant according to the present embodiment is obtained by melting a 50 kg steel ingot using a high-frequency melting furnace. Forged. Furthermore, in order to prevent a forge crack, it carried out at the temperature of 1150 degrees C or less. The forged steel was annealed and then heated to 1050 ° C. and subjected to a quenching process simulating the rotor shaft (in the actual rotor shaft, water spray cooling is performed), and then tempered at 680 to 740 ° C. And a creep rupture test piece was prepared. Table 1 shows the chemical composition (mass%) of the steel ingot. No. 1-No. 3 is the material of the present invention, No. 3. 4 and no. Reference numeral 5 is a comparative material.

Table 2 shows the creep rupture strength of the test material at 650 ° C. As shown in Table 2, the content of Cr (Comparative material of No. 4) exceeding 10% and Ni (Comparative material of No. 5) exceeding 0.1% is 10% in the specific composition of the present embodiment. ^There is almost no difference in composition between the ³ h (time) and the 10 ⁴ h creep rupture strength, but the 10 ⁵ h creep rupture strength is particularly lowered, and should be less than that. No. 1-No. In the present invention material 3, the content of Cr and Ni is reduced, and (100 × C + Cr) is in the range of 15.5 to 20.5 and (5 × Ni + Mo) is in the range of 0.3 to 0.9. It can be seen that the creep rupture strength is improved to 98 N / mm ² or more at the long time side of 10 ⁵ h, and the creep rupture strength is excellent at the long time side.

  The rotor shaft in the present embodiment is used for a high- and medium-pressure integrated turbine in which a steam temperature inlet temperature to the first stage blade is 600 ° C. or higher, an intermediate-pressure turbine, or a high-pressure turbine unit and an intermediate-pressure turbine unit. Can do. These steam turbines serve as rotor shafts having a double-flow structure rotor blade implanting structure that flows toward the outside in opposite directions. Furthermore, the cladding part of any rotor shaft is provided with a cladding of Cr—Mo low alloy steel having a bainite structure or a sleeve thereof. In particular, the present embodiment is suitable for an ultra super critical pressure power plant having a high power turbine of 600 MW, a medium pressure turbine of 620 ° C., or a single machine output using a steam temperature of the high pressure turbine and the medium pressure turbine of 620 ° C. of 1000 MW or more. Furthermore, these steam temperatures can be applied to 630-650 ° C.

<< First Embodiment >>
Table 3 shows main specifications of the steam temperature of 625 ° C. and the 1050 MW steam turbine according to the first embodiment. The steam turbine power plant according to the first embodiment has a cross-compound type four-flow exhaust, a low-pressure turbine having a blade portion of a last stage blade having a length of 1092 mm (43 inches), and the turbine configuration A is HP (high-pressure turbine). (High pressure part) -IP (Medium pressure turbine (Medium pressure part)) and LP (Low pressure turbine (Low pressure part)) 2 units, 3000rpm, Turbine configuration B is HP-LP and IP-LP, 3000rpm respectively The high-strength 10Cr steel shown in Table 4 is used for rotor shafts (high-pressure rotor shafts and medium-pressure rotor shafts) exposed to high temperatures of HP and IP based on the results obtained by the above-described manufacturing method. It is done.
The steam temperature of the high-pressure part (HP) is 625 ° C. and a pressure of 24.5 MPa (250 kgf / cm ² ), and the steam temperature of the medium-pressure part (IP) is heated to 625 ° C. by a reheater. It is operated at a pressure of 6.4 MPa (45 to 65 kgf / cm ² ). The vapor temperature of the low pressure part (LP) enters at 400 ° C. and is sent to the condenser with a vacuum of 100 ° C. or less and 96.3 kPa (722 mmHg).

  The total distance between the bearings in which the high-pressure turbine and the medium-pressure turbine are coupled in tandem and the distance between the bearings of the two low-pressure turbines coupled in tandem is approximately 31500 mm, which is compact.

(Steam turbine power plant 100)
As shown in FIG. 1, the steam turbine power plant 100 according to the first embodiment is a cross-compound type shown in the turbine configuration A of Table 3 and includes a coal-fired boiler 101, a high-pressure turbine 110, and a middle steam generator. Pressure turbine 120, two low-pressure turbines 130 coupled in tandem, condenser 102, condensate pump 103, low-pressure feed water heater system 104, deaerator 105, booster pump (not shown), feed water pump 106, high-pressure feed water heating It includes a system 107 and the like.
The first generator G1 is coupled to the intermediate pressure turbine 120 via the generator rotor shaft 10a, and the second generator G2 is coupled to the low pressure turbine 130 via the generator rotor shaft 10b. Are combined.

  Although not shown, as another form of cross-compound type, as shown in turbine configuration B of Table 3, a high-pressure turbine, a low-pressure turbine, and a generator (first generator) are coupled in tandem, The turbine, the low-pressure turbine, and the generator (second generator) may be coupled in tandem.

The super high temperature and high pressure steam generated in the coal-fired boiler 101 enters the high-pressure turbine 110 to generate power, and is then reheated again in the reheater 101a of the coal-fired boiler 101 and enters the intermediate-pressure turbine 120 for power. generate. The exhaust steam from the intermediate pressure turbine 120 enters the low pressure turbine 130 to generate power, and then condenses in the condenser 102. This condensate (feed water) is sent to the deaerator 105 by the condensate pump 103 via the low-pressure feed water heater system 104. The feed water deaerated by the deaerator 105 is sent to a high-pressure feed water heater system 107 by a booster pump and a feed water pump 106 (not shown), and after being heated, returns to the coal-fired boiler 101.
Note that a feed water pump driving turbine (not shown) that is operated by extracted steam from the intermediate pressure turbine 120 is used to drive the feed water pump 106.

  In the coal-fired boiler 101, the feed water becomes high-temperature and high-pressure steam through the economizer 101b, the evaporator 101c, and the superheater 101d. On the other hand, the boiler combustion gas that has heated the steam exits the economizer 101b and then enters an air heater (not shown) to heat the air.

(High pressure turbine 110)
As shown in FIG. 2, the high-pressure turbine 110 includes a high-pressure rotor shaft 23 in which eight high-pressure blades 16 are implanted in a high-pressure external casing 19 as an external casing and a high-pressure internal casing 18 as an internal casing. (Rotor shaft) is housed.
In the present embodiment, the eight-stage high-pressure blade 16 is implanted on one side of the high-pressure rotor shaft 23 with respect to the position of the main steam inlet 28 as a steam inlet, and is implanted most on the main steam inlet 28 side. The high pressure blade 16 becomes the first stage blade 161 (first stage of the high pressure blade 16).
Further, the high-pressure blade 16 is a saddle type dovetail type, double tenon, and the length of the blade portion of the first stage blade 161 is about 35 mm.
Further, each stationary blade 14 is provided corresponding to the high-pressure moving blade 16, and the stationary blade 14 corresponding to the first-stage moving blade 161 is referred to as a first-stage stationary blade 141.
Note that the number of stages of the high-pressure moving blades 16 may be appropriately changed according to the output of the high-pressure turbine 110, for example, and 9 to 12 stages are suitable depending on the output of the high-pressure turbine 110.
Further, for example, the high-pressure moving blade 16 may be configured to have 8 stages (or 9 stages or more) implanted symmetrically in a side view with the position of the main steam inlet 28 as the center.

The high-temperature and high-pressure steam generated in the coal-fired boiler 101 (see FIG. 1) passes from the main steam pipe 25a through the flange and elbow 25, through the main steam inlet 28, through the nozzle box 38, and through the high-pressure turbine 110. It is taken in.
The high-temperature and high-pressure steam taken from the main steam inlet 28 into the high-pressure turbine 110 is divided along the high-pressure rotor shaft 23 into a flow toward the first stage blades 161 and a flow away from the first stage blades 161. The steam flowing away from the first stage moving blade 161 is returned to the first stage moving blade 161 by the return flow path 16a. With this configuration, the first stage blade 161 becomes a double flow.

  The length of the rotor shaft between the first bearing 1 and the second bearing 2 that supports the high-pressure rotor shaft 23 at both ends of the high-pressure turbine 110 is about 5300 mm, and the portion of the high-pressure rotor shaft 23 corresponding to the stationary blade 14 is the most. The diameter of the thin portion is about 710 mm, and the ratio of the rotor shaft length to the thinnest portion of the diameter of the high-pressure rotor shaft 23 is about 7.5.

  The materials shown in Table 4 to be described later are used for the first stage blade 161 (blade first stage) and the first stage stationary blade 141 (nozzle first stage), and the other high-pressure blade 16 (blade) and the stationary blade 14 (nozzle) are all W, It is composed of 12% Cr steel not containing Co and B. The length of the blade portion of the high pressure moving blade 16 is 35 to 50 mm for the first stage moving blade 161, and is 65 to 180 mm from the second stage of the high pressure moving blade 16 (next stage of the first stage moving blade 161) toward the final stage. It stretches at a ratio of 1.10 to 1.15 with respect to the length of the wing part at the front stage in length, and the stretch ratio gradually increases toward the final stage.

(Medium pressure turbine 120)
As shown in FIG. 2, the intermediate pressure turbine 120 is steam (reheated steam) discharged from the high pressure turbine 110 and heated again to 625 ° C. by the reheater 101 a (see FIG. 1) of the coal-fired boiler 101. The first generator G1 (see FIG. 1) is driven together with the high-pressure turbine 110 by the applied power, and is rotated at a rotational speed of 3000 rpm. The intermediate pressure turbine 120 includes an intermediate pressure outer casing 22 as an outer casing, an intermediate pressure inner first casing 20 and an intermediate pressure inner second casing 21 as inner casings, and an intermediate pressure rotor shaft 24 (rotor A stationary blade 15 is provided corresponding to the intermediate pressure rotor blade 17 implanted in the shaft.

The intermediate pressure blade 17 takes reheated steam into the intermediate pressure turbine 120 and is symmetrical in side view with respect to the position of the warm-up steam inlet 40 serving as a steam inlet in the longitudinal direction of the intermediate pressure rotor shaft 24. There are 6 stages along each.
Further, the intermediate pressure rotor blades 17 implanted at the most warm-up steam inlet 40 side in the center of the intermediate pressure rotor shaft 24 are respectively referred to as first stage rotor blades 171 (first stage of the intermediate pressure rotor blades 17). With this structure, the medium pressure rotor blade 17 becomes a double flow.
The stationary blade 15 corresponding to the first stage moving blade 171 of the intermediate pressure moving blade 17 is defined as the first stage stationary blade 151.
The length of the blade portion of the first stage moving blade 171 is about 100 mm, and the length of the blade portion of the final stage is about 230 mm. The two-stage dovetail of the first stage rotor blade 171 and the medium pressure rotor blade 17 (next stage of the first stage rotor blade 171) is an inverted Christmas tree type. The rotor shaft length between the third bearing 4 and the fourth bearing 4 that supports the intermediate pressure rotor shaft 24 at both ends of the intermediate pressure turbine 120 is about 5800 mm, which is the stationary blade before the final stage of the intermediate pressure rotor blade 17. 15 is about 9.2 times the diameter (about 630 mm) of the medium-pressure rotor shaft 24 corresponding to 15.
Note that the number of stages of the intermediate-pressure moving blades 17 may be appropriately changed according to the output of the intermediate-pressure turbine 120, for example.

In the first embodiment, the materials shown in Table 4 to be described later are used for the first-stage moving blade 171 (blade first stage) and the first-stage stationary blade 151 (nozzle first stage) of the intermediate-pressure turbine 120. As a material for the (blade) and the stationary blade 15 (nozzle), 12% Cr steel not containing W, Co, and B is used.
Further, the length of the blade portion of the intermediate pressure blade 17 becomes longer at each stage from the first stage blade 171 toward the final stage, and from the first stage blade 171 to the last stage according to the output of the intermediate pressure turbine 120. Is set to 60 to 300 mm, and the length of the intermediate pressure rotor blade 17 of each stage is a length adjacent to the previous stage from the second stage to the last stage, 1.1 to 1.1 mm. It is long at a rate of 1.2.

  In the intermediate pressure rotor shaft 24, the implanted portion of the intermediate pressure rotor blade 17 has a larger diameter than the portion corresponding to the stationary blade 15, and the axial width of the implanted portion is the intermediate pressure rotor blade 17. The larger the wing length, the larger. The ratio of the width of the implanted portion to the length of the blade portion of the medium pressure rotor blade 17 is 0.35 to 0.8 from the first stage rotor blade 171 to the last stage, and from the first stage rotor blade 171 toward the last stage. It is getting smaller step by step.

  The first stage moving blade 161 of the high pressure turbine 110 has a saddle type implantation, and the implanted portion of the high pressure moving blade 16 after the second stage of the high pressure turbine 110 and the intermediate pressure moving blade 17 of all stages of the intermediate pressure turbine 120 are implanted. The part is a reverse Christmas tree type.

(Low pressure turbine 130)
In the steam turbine power plant 100 (see FIG. 1) according to the first embodiment, as shown in the turbine configuration A of Table 3, two low-pressure turbines 130 are coupled in tandem, and the two low-pressure turbines 130 are It is the same structure.
As shown in FIG. 3, the low-pressure blades 41 of the low-pressure turbine 130 are planted in eight stages symmetrically in the lateral direction along the longitudinal direction of the low-pressure rotor shaft 44 (rotor shaft), with the position of the nozzle box 45 as the center. It is installed. A stationary blade 42 is provided corresponding to the low pressure blade 41. The nozzle box 45 is a double flow type.

The low-pressure rotor shaft 44 includes, by mass, C 0.2 to 0.3%, Si 0.03 to 0.1%, Mn 0.1 to 0.2%, P 0.01% or less, S 0.01% or less, Ni 3 0.5 to 4.5%, Cr 1.8 to 2.5%, Mo 0.3 to 0.5%, V 0.1 to 0.2%, Al 0.01% or less, Sn 0.005% or less, As 0.005 %, And super-clean tempered bainite steel containing Sb 0.001% or less is used.
These steels are heated at 840 ° C. for 3 hours after hot forging, quenched at 100 ° C./h, tempered at 575 ° C. for 32 hours, and have a total tempered bainite structure. The low-pressure rotor shaft 44 has a 0.02% yield strength of 784 N / mm ² (80 kgf / mm ² ) or more, a 0.2% yield strength of 858 N / mm ² (87.5 kgf / mm ² ) or more, and a tensile strength of 981 N / mm ² ( 100 kgf / mm ² ) or more, V notch impact value of 98 J / cm ² or more, FATT has a high strength and toughness of −20 ° C. or less, and the wing length is 1092 to 1270 mm (43 to 50 inches) as the final stage. The low pressure rotor blade 41 can be implanted.

The 1092 mm (43 inch) blades of the low-pressure turbine 130 in the first embodiment include C0.14%, Si0.04%, Mn0.15%, Cr11.5%, Ni2.60%, Mo2.30%, and V0. Quenching and tempering were performed using martensitic steel containing 27%, Nb 0.10% and N 0.07%. This material had a tensile strength of 1314 N / mm ² (134 kgf / mm ² ) and a V-notch impact value of 49 J / cm ² .

For the low-pressure blade 41 and the stationary blade 42 other than the final stage, 12% Cr steel containing 0.1% Mo is used. C0.25% cast steel is used for the inner and outer casings.
The low-pressure rotor shaft 44 is supported by low-pressure bearings 43 at both ends of the low-pressure turbine 130, the distance between the centers of the low-pressure bearings 43 is 7500 mm, the diameter of the low-pressure rotor shaft 44 corresponding to the stationary blade 42 is about 1280 mm, The diameter at the implantation part is 2275 mm.

  For the erosion shield for preventing erosion due to water droplets in the steam, a Co-based alloy stellite plate containing C1.0%, Cr28.0% and W4.0% by mass was joined by electron beam welding. In the first embodiment, a continuous cover (not shown) is formed by cutting after forging as a whole. The continuous cover can also be formed mechanically and integrally.

  In the first embodiment, the low-pressure turbine 130 shown in FIG. 3 has the central portion side (nozzle box 45 side) of the low-pressure rotor shaft 44 as the first stage moving blade 411 and the axial width of the implanted portion of the low-pressure moving blade 41. However, the first stage blades 411 to 3 stages, 4 stages, 5 stages, 6 stages to 7 stages, and 8 stages are gradually increased, and the width of the final stage is about 2 compared to the width of the first stage rotor blades 411. .5 times larger.

  The portion of the low-pressure rotor shaft 44 corresponding to the stationary blade 42 has a small diameter, and the axial width of the portion is five, six, and seven steps from the first-stage moving blade 411 side of the low-pressure moving blade 41. The width gradually increases in three stages, and the width on the final stage side is about 1.9 times larger than that between the first stage rotor blade 411 and the second stage.

  The implanted portion of the low pressure rotor blade 41 in the low pressure rotor shaft 44 has a larger diameter of the low pressure rotor shaft 44 and the length of the blade portion of the low pressure rotor blade 41 than the portion corresponding to the stationary blade 42. The width of the implanted part is larger. The ratio of the width of the implanted portion to the length of the blade portion of the low pressure moving blade 41 is 0.15 to 0.19 from the first stage moving blade 411 to the last stage, and gradually from the first stage moving blade 411 toward the last stage. It is getting smaller.

  In addition, the width between the low-pressure blade 41 and the low-pressure blade 41 in the portion corresponding to each stationary blade 42 is the first-stage stationary blade 421 (the stationary blade 42 relative to the first-stage stationary blade 411) and the two stages (first-stage stationary blade 42). It increases in stages at each stage from the stage between the next stage of the stationary blade 421 and the stage before the last stage. The ratio of the width to the length of the blade portion of the low-pressure moving blade 41 is 0.25 to 1.25, and decreases from the first-stage moving blade 411 toward the final stage.

  Two low-pressure turbines 130 are coupled in tandem, and the total distance between the bearings (the distance between the two low-pressure bearings 43) is about 18300 mm, and the blade length of the low-pressure blade 41 of the low-pressure turbine 130 (for example, The ratio of the total distance between the bearings of the two low-pressure turbines 130 connected in tandem to 1092 mm (43 inches) is 16.7.

  Note that the steam inlet temperature to the high pressure turbine 110 (see FIG. 1) and the medium pressure turbine 120 (see FIG. 1) is 610 ° C., and the steam inlet temperature to the two low pressure turbines 130 (see FIG. 1) is 385 ° C. The same configuration can be applied to a large-capacity power plant.

  In the steam turbine power plant 100 (see FIG. 1) provided with the high-pressure turbine 110 (see FIG. 2), the medium-pressure turbine 120 (see FIG. 2), and the low-pressure turbine 130 (see FIG. 3) configured as described above, high-pressure feed water is provided. Since the temperature of the feed water leaving the heater system 107 (see FIG. 1) is much higher than the feed water temperature in the conventional thermal power plant, the economizer 101b (see FIG. 1) in the coal-fired boiler 101 is inevitably produced. The temperature of the combustion gas that has exited) is much higher than that of conventional boilers. For this reason, heat recovery from the boiler exhaust gas is attempted so as not to lower the combustion gas temperature.

1050 MW class generator rotor shaft (generator rotor shaft 10a for coupling the intermediate pressure turbine 120 and the first generator G1, and generator rotor shaft 10b for coupling the low pressure turbine 130 and the second generator G2, see FIG. 1) ) Having higher strength is used. In particular, C0.15-0.30%, Si0.1-0.3%, Mn0.5% or less, Ni3.25-4.5%, Cr2.05-3.0%, Mo0.25-5. 60%, has a fully tempered bainite structure containing V0.05～0.20% at room temperature tensile strength of ^{912N / mm 2 (93kgf / mm} 2) or more, particularly ^{981N / mm 2 (100kgf / mm} 2) or more 50% FATT is 0 ° C. or less, particularly −20 ° C. or less, and the magnetization force at 21.2 KG is 985 AT / cm or less, and the total amount of P, S, Sn, Sb and As as impurities is What makes 0.025% or less and Ni / Cr ratio 2.0 or less is preferable.

  A central hole is formed in any of the high pressure rotor shaft 23 (see FIG. 2) of the high pressure turbine 110, the intermediate pressure rotor shaft 24 (see FIG. 2) of the intermediate pressure turbine 120, and the low pressure rotor shaft 44 (see FIG. 3) of the low pressure turbine 130. Through this central hole, the presence or absence of defects is inspected by ultrasonic inspection, visual inspection, and fluorescent flaw detection. Further, an ultrasonic inspection can be performed from the outer surface, and a configuration without a central hole may be employed.

Table 4 shows the chemical composition (mass%) of materials used for the main parts of the high-pressure turbine 110, the intermediate-pressure turbine 120, and the low-pressure turbine 130 according to the steam turbine power plant 100 shown in FIG. 1 in the first embodiment. . In the first embodiment, the high-temperature part (HP) and the high-temperature part (IP) are all made of a ferrite-based crystal structure with a thermal expansion coefficient of about 12 × 10 ⁻⁶ / ° C. There was no problem due to the difference in expansion coefficient.

The rotor shafts of the high-pressure turbine 110 and the intermediate-pressure turbine 120 (high-pressure rotor shaft 23 and intermediate-pressure rotor shaft 24) shown in FIG. Then, cast into a mold and forge to produce an electrode rod, and then remelt the electroslag to dissolve from the upper part to the lower part of the cast steel, and forge it into a rotor shape (diameter: 1050 mm, length: 3700 mm) And molded. This forging was performed at a temperature of 1150 ° C. or lower in order to prevent forging cracks. Further, this forged steel is annealed and heated to 1050 ° C., water spray cooling quenching treatment is performed twice at 570 ° C. and 700 ° C., and the final shape is obtained by cutting.
In the high pressure turbine 110 shown in FIG. 2, the lower side of the electroslag steel ingot is set to the first stage moving blade 161 side of the high pressure moving blade 16 and the upper side is set to the final stage side.
Moreover, although both the high pressure rotor shaft 23 and the medium pressure rotor shaft 24 have a center hole, the center hole can be eliminated by reducing impurities. Then, (5 × Ni + Mo) = 0.33, (100 × C + Cr) = 17.2, 10 ³ hours 650 ° C. in the center of the high pressure rotor shaft 23 and intermediate pressure rotor shaft 24 of the first embodiment The creep rupture strength at 10 ⁴ hours and 10 ⁵ hours is No. 1 in Table 1. It was equivalent to 1-3. In particular, it showed high strength on the long time side.

Further, as a result of investigating the central portions of the high-pressure rotor shaft 23 and the intermediate-pressure rotor shaft 24, the characteristics required for the high-pressure rotor shaft 23, the intermediate-pressure rotor shaft 24, and the rotor shaft of the high-medium-pressure integrated steam turbine described later. (625 ℃, 10 ⁵ h creep rupture strength ≧ 98N / ^mm 2, 20 ℃ impact absorption energy ≧ 14.7J) it was confirmed that sufficiently satisfy. Thus, it was demonstrated that a rotor shaft for a steam turbine that can be used in steam at 620 ° C. or higher can be manufactured.

  The moving blades (blades) and stationary blades (nozzles) of the high-pressure turbine 110 (see FIG. 2) and the intermediate-pressure turbine 120 (see FIG. 2) are similarly melted in a vacuum arc melting furnace to heat The material shape of the wing and the stationary blade (width 150 mm, height 50 mm, length 1000 mm) was forged and molded. This forging was performed at a temperature of 1150 ° C. or lower in order to prevent forging cracks. The forged steel is heated to 1050 ° C., subjected to oil quenching, tempered at 690 ° C., and then cut into a predetermined shape.

As a result of investigating this blade characteristics, high pressure, characteristics required for the first stage moving blade of the intermediate pressure steam turbine (625 ° C., 10 ⁵ h creep rupture strength ≧ 147N / mm ²⁾ be sufficiently satisfied confirmed. As a result, it was demonstrated that a moving blade for a steam turbine that can be used in steam at 620 ° C. or higher can be manufactured.

  The main casing (not shown) of the internal casings of the high-pressure turbine 110 and the intermediate-pressure turbine 120 (the high-pressure internal casing 18, the intermediate-pressure internal first casing 20, and the intermediate-pressure internal second casing 21) shown in FIG. The valve casing and the steam control valve casing were prepared by melting the heat-resistant cast steel shown in Table 4 in an electric furnace, refining the ladle, and casting it into a sand mold. By carrying out sufficient refining and deoxidation before casting, a product having no casting defects such as shrinkage cavities was obtained. The weldability evaluation using this casing material was performed according to JISZ3158. Preheating, between passes, and after heat start temperature were 200 ° C., and post heat treatment was 400 ° C. × 30 minutes. The material of the present invention had no weld cracks and good weldability.

Furthermore, the results of the examination of the characteristics of the casing, high pressure, medium pressure, and below to high-intermediate pressure characteristics required for integrated steam turbine casing (625 ° C., 10 ⁵ h creep rupture strength ≧ 68N / mm ^2, 20 It was confirmed that the impact absorption energy of ≧ 9.8 J) was sufficiently satisfied and welding was possible. This demonstrated that a steam turbine casing that can be used in steam at 620 ° C. or higher can be produced.

  In the first embodiment, Cr—Mo low alloy steel is welded to the journal portions of the rotor shafts of the high-pressure turbine 110 and the intermediate-pressure turbine 120 to improve bearing characteristics. As the test welding rods, (mass%) covered arc welding rods (4.0 mm in diameter) shown in Table 5 were used, and overlay welding was performed in combination with the welding rods used for each layer shown in Table 6. It was. The thickness of each layer was 3-4 mm, the total thickness was about 28 mm, and the surface was ground about 5 mm. The welding conditions are preheating, between passes, stress relief annealing (SR) start temperature is 250 to 350 ° C., and SR treatment conditions are 630 ° C. × 36 hours.

  In order to confirm the performance of the welded part, overlay welding was similarly performed on the plate material, and a 160 ° side bending test was performed. However, no crack was observed in the welded part. There was no adverse effect on the material, and it was excellent in oxidation resistance.

<< Second Embodiment >>
Table 7 shows the main specifications of a steam turbine power plant with a steam temperature of 600 ° C. and a rated output of 700 MW. The second embodiment is a tandem compound double flow type, a wing part length of 1168 mm (46 inches) in a low-pressure turbine, HP (high pressure part) / IP (medium pressure part) integrated type, and LP (low pressure) Part) One (C) or two (D) has a rotational speed of 3000 rpm, and the high-pressure part and the low-pressure part are composed of the main materials shown in Table 4 described above.
The steam temperature of the high pressure part (HP) is 600 ° C. and a pressure of 24.5 MPa (250 kgf / cm ² ), and the steam temperature of the intermediate pressure part (IP) is heated to 600 ° C. by a reheater. It is operated at a pressure of 6.4 MPa (45 to 65 kgf / cm ² ). The vapor temperature of the low pressure part (LP) enters at 400 ° C. and is sent to the condenser with a vacuum of 100 ° C. or less and 96.3 kPa (722 mmHg).

(Steam turbine power plant 100a)
As shown in FIG. 4, the steam turbine power plant 100a according to the second embodiment is a tandem compound double flow type shown in the turbine configuration D of Table 7, and includes a high-medium pressure integrated turbine 140 and two low-pressure turbines. The turbine 130a is provided in tandem, and the distance between the bearings is about 22700 mm.
A generator G is coupled to the low-pressure turbine 130a via a generator rotor shaft 10c.
The distance between the bearings (22700 mm) is 19.4 times as long as the blade length (1168 mm) of the rotor blade in the final stage of the low-pressure turbine 130a.
The total distance between the bearings per 1 MW of the rated output 700 MW of the steam turbine power plant 100a is 32.4 mm.
Other configurations are the same as those of the steam turbine power plant 100 shown in FIG.

Although not shown, as another form of the tandem compound double flow type, as shown in the turbine configuration C of Table 7, one low-pressure turbine is connected to the high-medium pressure integrated turbine in tandem. There may be.
In this way, the steam turbine power plant including one low-pressure turbine has a distance between bearings of about 14700 mm and a length of blades (1168 mm) of the last stage moving blade of the low-pressure turbine. A configuration in which the distance is 6 times and the total distance between the bearings per rated output of 1 MW is 21.0 mm is preferable.

The ultra-high temperature and high pressure steam generated in the coal-fired boiler 101 shown in FIG. 4 flows into a high-pressure turbine section 140a (see FIG. 5), which will be described later, after the high-medium pressure integrated turbine 140 to generate power, and then coal-fired again. It is reheated by the reheater 101a of the boiler 101 and flows into an intermediate pressure side turbine section 140b (see FIG. 5), which will be described later, to generate power.
The exhaust steam of the high-medium pressure integrated turbine 140 flows into the low-pressure turbine 130 a to generate power, and then condenses in the condenser 102. This condensate (feed water) is sent to the deaerator 105 by the condensate pump 103 via the low-pressure feed water heater system 104. The feed water deaerated by the deaerator 105 is sent to a high-pressure feed water heater system 107 by a booster pump and a feed water pump 106 (not shown) and heated, and then returns to the coal-fired boiler 101.

Here, in the coal-fired boiler 101, the feed water becomes high-temperature and high-pressure steam through the economizer 101b, the evaporator 101c, and the superheater 101d.
The boiler combustion gas that has heated the steam exits the economizer 101b and then enters an air heater (not shown) to heat the air.
Note that the feed water pump 106 is driven by a feed water pump drive turbine (not shown) that operates with extracted steam from the intermediate pressure turbine section 140b (see FIG. 5) of the high-medium pressure integrated turbine 140.

(High and medium pressure integrated turbine 140)
As shown in FIG. 5, the high and intermediate pressure integrated turbine 140 provided in the steam turbine power plant 100a (see FIG. 4) has a structure in which a high pressure side turbine portion 140a and an intermediate pressure side turbine portion 140b are coupled in tandem.
The high-pressure turbine section 140a includes a high- and medium-pressure rotor shaft 33 (rotor shaft) in which high-pressure blades 16 are implanted in a high-pressure internal casing 18 as an internal casing and a high-pressure external casing 19 as an external casing outside the high-pressure turbine section 140a. It is equipped.
The high-temperature and high-pressure steam is obtained by the coal-fired boiler 101 (see FIG. 4), passes through the flange and elbow 25, passes from the main steam pipe 25a to the main steam inlet 28 which is the steam inlet, and passes through the nozzle box 38. It is guided to the first stage moving blade 161 of the high pressure moving blade 16. Steam has a structure in which it flows in from the central portion of the high and medium pressure rotor shaft 33 and flows toward the high pressure side bearing 53 side. The high pressure rotor blades 16 are provided in eight stages on the left side of the high pressure side turbine section 140a in the drawing, and the stationary blades 14 are provided corresponding to the high pressure rotor blades 16, respectively.
The high pressure moving blade 16 is a saddle type or getter type, dovetail type, double tenon, and the first stage moving blade 161 of the high pressure moving blade 16 has a blade portion length of about 40 mm.

The main components of the high-medium pressure integrated turbine 140 and the low-pressure turbine 130a (see FIG. 4) included in the steam turbine power plant 100a (see FIG. 4) according to the second embodiment include the chemical composition (mass shown in Table 4). %) Was used.
As the high and medium pressure rotor shaft 33, the same one as the high pressure rotor shaft 23 (see FIG. 2) of the high pressure turbine 110 according to the first embodiment was used. The high and medium pressure rotor shaft 33 has a center hole, and in particular, P is 0.010% or less, S0.005% or less, As0.005% or less, Sn0.005% or less, and Sb0.003% or less. The central hole can be eliminated by high purification. Furthermore, overlay welding of Cr—Mo low alloy steel to the high pressure side bearing 53 (see FIG. 5) and the medium pressure side bearing 54 (see FIG. 5) which support the high / medium pressure rotor shaft 33 at both ends of the high / medium pressure integrated turbine 140. The layer was formed similarly. Further, the generator rotor shaft 10c (see FIG. 4) for connecting the low-pressure turbine 130a (see FIG. 4) and the generator G (see FIG. 4) has a high strength as in the first embodiment. It is done.

  The high / medium pressure rotor shaft 33 of the high pressure turbine section 140a of the high / medium pressure integrated turbine 140 shown in FIG. 5 has a width of the first stage moving blade 161 of the high pressure moving blade 16 and the last stage moving blade implantation root portion. The second stage to the seventh stage are the smallest, 0.40 to 0.56 times as large as the first stage moving blade 161, and the same size, and the last stage is composed of the first stage moving blade 161 and the second to seventh stage. The size is between 0.46 and 0.62 times that of the first stage moving blade 161.

  The length of the blade portion of the high-pressure moving blade 16 in the high-pressure side turbine portion 140a is 35 to 50 mm for the first-stage moving blade 161, and is longer in each stage from the second stage to the final stage, and particularly varies depending on the output of the steam turbine. The length from the second stage to the last stage is in the range of 50 to 150 mm, and the number of stages is in the range of 7 to 12 stages. And the length of the wing part of each stage is long in the range of 1.05-1.35 times the length adjacent to the previous stage from the second stage to the last stage, The ratio is gradually increasing.

The intermediate pressure side turbine section 140b is discharged from the high pressure side turbine section 140a and is heated again to 600 ° C. by the reheater 101a (see FIG. 4), and the high pressure is increased via the reheat steam intake 51 (steam inlet). The steam flowing from the central portion of the rotor shaft 33 rotates the generator G (see FIG. 4) together with the low-pressure turbine 130a (see FIG. 4), and is rotated at a rotational speed of 3000 rpm.
The intermediate pressure side turbine section 140b includes intermediate pressure blades in an intermediate pressure internal first casing 20, an intermediate pressure internal second casing 21, and an intermediate pressure external casing 22 as an outer casing outside thereof. A high and medium pressure rotor shaft 33 in which 17 is implanted is supported.
And the stationary blade 15 is provided corresponding to the intermediate pressure rotor blade 17 implanted in the high intermediate pressure rotor shaft 33.
The intermediate pressure blade 17 is provided in six stages up to the final stage in the direction away from the high pressure turbine section 140a, with the high pressure turbine section 140a side serving as the first stage blade 171.
The length of the first stage blade 171 of the medium pressure blade 17 is about 130 mm, and the length of the last stage blade is about 260 mm. And the dovetail is a reverse Christmas tree type.

  In the medium pressure side turbine section 140b, the high intermediate pressure rotor shaft 33 has the largest axial width of the root blade implantation root portion of the intermediate pressure rotor blade 17 at the first stage rotor blade 171 and two stages smaller than that, and the third to fifth stages. Is smaller than two stages, both of which are the same, and the axial width of the root part of the rotor blade implantation at the final stage is between 3 and 5 and 2 stages, and 0.48 to 0. It is 64 times. The first stage moving blade 171 is 1.1 to 1.5 times as large as the second stage.

  The length of the blade portion of the intermediate pressure rotor blade 17 in the intermediate pressure side turbine portion 140b is increased in each stage from the first stage rotor blade 171 toward the final stage, and the length of the blade section that varies depending on the output of the steam turbine is The length from the first stage moving blade 171 to the last stage is 90 to 350 mm, and the number of stages is in the range of 6 to 9 stages. The length of the blade part of each stage is from the second stage to the last stage with respect to the previous stage. The adjacent lengths are longer at a rate of 1.10 to 1.25.

  In the implanted portion of the intermediate pressure blade 17, the diameter of the high intermediate pressure rotor shaft 33 is larger than that of the portion corresponding to the stationary blade 15, and the width thereof corresponds to the length and position of the blade portion of the intermediate pressure blade 17. Involved. The ratio of the intermediate pressure rotor blade 17 to the blade length of the implanted part width is the largest in the first stage rotor blade 171, 1.35 to 1.80 times, and the second stage is 0.88 to 1.18 times 3 Stages to 6 stages become smaller toward the final stage, which is 0.40 to 0.65 times.

  In the second embodiment, the high-medium pressure integrated turbine 140 (see FIG. 5) of the steam turbine power plant 100a (see FIG. 4) including the two low-pressure turbines 130a coupled to the tandem has an inter-bearing distance (high-pressure side). The distance between the bearing 53 and the intermediate pressure side bearing 54) is about 6700 mm, 5.7 times the blade length (1168 mm) of the final stage of the moving blade of the low pressure turbine 130a, and per rated output of 1 MW. 9.57 mm.

  Also in the second embodiment, the high-pressure bearing 53 (see FIG. 5) and the medium-pressure bearing 54 (see FIG. 5) of the high and medium pressure rotor shaft 33 (see FIG. 5) of the high and medium pressure integrated turbine 140 (see FIG. 5). As in the first embodiment, a build-up weld layer of low alloy steel is provided.

(Low pressure turbine 130a)
FIG. 6 is a cross-sectional view showing the structure of a low-pressure turbine provided in the steam turbine power plant according to the second embodiment.
As shown in FIG. 4, in the steam turbine power plant 100a according to the second embodiment, two low-pressure turbines 130a are coupled in tandem, and are further coupled in tandem with the high-medium pressure integrated turbine 140.

As shown in FIG. 6, the low-pressure blade 41 of the low-pressure turbine 130 a provided in the steam turbine power plant 100 a (see FIG. 4) has six stages left and right symmetrically in the side view centering on the position of the nozzle box 45. Corresponding to 41, a stationary blade 42 is provided.
In the low pressure rotor blade 41, the central portion side (nozzle box 45 side) of the low pressure rotor shaft 44 is the first stage rotor blade 411, and the last stage rotor blade 41 has a blade portion length of 1168 mm (46 inches).
For the rotor blade 41, Ti-based alloy or high-strength 12% Cr steel is used as in the low-pressure turbine 130 (see FIG. 2) according to the first embodiment.
As for the low-pressure rotor shaft 44, forged steel having a super-tempered tempered bainite structure is used similarly to the low-pressure turbine 130 (see FIG. 2) according to the first embodiment. 12% Cr steel containing 0.1% Mo is used for the low pressure blade 41 and the stationary blade 42 other than the final stage and the preceding stage.
Further, cast steel having the above-described composition of C0.25% is used for an inner / outer casing material (not shown) containing the low-pressure rotor shaft 44, the low-pressure rotor blade 41, the stationary blade 42, and the like. The distance between the centers of the bearings 43 in the second embodiment is 8000 mm, the diameter of the low-pressure rotor shaft 44 corresponding to the stationary blade 42 is about 800 mm, and the diameter of the low-pressure rotor shaft 44 in the implanted portion of the moving blade 41 is the same in each stage. is there. The distance between the bearing centers with respect to the diameter of the low-pressure rotor shaft 44 corresponding to the stationary blade 42 is 10 times.

The 1168 mm (46 inch) blades of the low-pressure turbine 130a according to the second embodiment include C 0.23%, Si 0.06%, Mn 0.15%, Cr 11.4%, Ni 2.65%, Mo 3.10%, Quenching and tempering were performed using martensitic steel containing V0.25%, Nb0.11%, N0.06%. This material had a tensile strength of 1421 N / mm ² (145 kgf / mm ² ) and a V-notch impact value of 60.8 J / cm ² .

  The low-pressure rotor shaft 44 is provided with an implanted portion of the low-pressure rotor blade 41, and a reverse Christmas tree type is similarly used for the final stage dovetail in addition to the fork type.

In the low-pressure turbine 130a shown in FIG. 6, the axial width of the root portion of the low-pressure moving blade 41 in the moving blade implantation is the smallest in the first-stage moving blade 411, and the second and third stages are equivalent to the fourth stage toward the final stage. The five stages are equivalent and gradually increase in four stages, and the width of the implanted part in the final stage is 6.2 to 7.0 times larger than the width of the implanted part of the first stage moving blade 411.
2nd and 3rd stages are 1.15 to 1.40 times the first stage rotor blade 411, 4th and 5th stages are 2nd and 3rd stages, 2.2 to 2.6 times, and the final stage is 4th and 5th stages. 2.8-3.2 times.
In addition, the width of the root embedded portion of the moving blade is indicated by a point connecting the extended line extending toward the end and the diameter of the low pressure rotor shaft 44.

  The length of the blade portion of the low-pressure moving blade 41 according to the second embodiment is longer at each step from the 102 mm (4 inches) of the first stage moving blade 411 toward the final stage of 1168 mm (46 inches). In eight stages, the length of the wing part of each stage is gradually increased from 1.2 to 1.9 times the length adjacent to the previous stage from the second stage to the last stage. .

  The blade root portion of the low pressure blade 41 has a larger diameter at the lower end of the low pressure rotor shaft 44 than the portion corresponding to the stationary blade 42, and the length of the blade portion of the low pressure blade 41 increases. The implantation width is large. The ratio of the width to the length of the blade portion of the low pressure moving blade 41 is 0.30 to 1.5 from the first stage moving blade 411 to before the final stage, and the ratio is from the first stage moving blade 411 to the front of the final stage. The ratio of the latter stage is gradually smaller within the range of 0.15 to 0.40 than the one immediately before. The final stage has a ratio of 0.50 to 0.65.

  The average diameter of the low-pressure rotor shaft 44 in the final stage of the low-pressure rotor blade 41 of the second embodiment is 2590 mm, 3600 rpm, 914 mm (36 inch) blade, 2160 mm, 3000 rpm, 1168 mm (3000 rpm, 1092 mm (43 inch) blade). 46 inch) blades were 2665 mm, 3600 rpm, 965 mm (38 inch) blades and 2220 mm.

  In the erosion shield of the low-pressure turbine 130a (see FIG. 6) according to the second embodiment, the stellite alloy plate is joined by electron beam welding or TIG welding in the same manner as the low-pressure turbine 130 (see FIG. 3) according to the first embodiment. Is done. The erosion shield is welded over the entire length of the erosion shield member at two locations on the front side and the back side where the wet steam directly hits. The front side is wider than the back side, and the upper and lower ends are also welded.

  In the steam turbine power plant 100a (see FIG. 4) including the high-medium pressure integrated turbine 140 (see FIG. 5) and the low-pressure turbine 130a (see FIG. 6) configured as described above, the high-pressure feed water heater system 107 (see FIG. 4). Since the temperature of the feed water leaving the reference) is much higher than the feed water temperature in the conventional thermal power plant, the combustion gas inevitably leaving the economizer 101b (see FIG. 4) in the coal-fired boiler 101 The temperature is much higher than that of conventional boilers. For this reason, heat recovery from the boiler exhaust gas is carried out so as not to lower the combustion gas temperature.

  In addition to the first and second embodiments, a 1000 MW class large capacity with a steam inlet temperature of 610 ° C. or higher, a steam inlet temperature to a low pressure turbine of about 400 ° C. and an outlet temperature of about 60 ° C. The same configuration can be applied to the power plant. In addition, even if it is 593 degreeC or 630 degreeC as vapor | steam temperature, the material structure and structure of this embodiment can be used as it is.

14 Stator Blade 15 Stator Blade 16 High Pressure Rotor (Robot)
17 Medium pressure blade (blade)
18 High-pressure interior compartment (inner casing)
20 Medium pressure internal first compartment (inner casing)
21 Medium pressure internal second compartment (inner casing)
23 High-pressure rotor shaft (rotor shaft for steam turbine)
24 Medium pressure rotor shaft (rotor shaft for steam turbine)
28 Main steam inlet (steam inlet)
40 Warm-up steam inlet (steam inlet)
DESCRIPTION OF SYMBOLS 100,100a Steam turbine power plant 101 Coal-fired boiler 101a Reheater 110 High-pressure turbine 120 Medium-pressure turbine 130 Low-pressure turbine 140 High-medium pressure integrated turbine 140a High-pressure side turbine part 140b Medium-pressure side turbine part 161,171 First stage moving blade (moving blade First stage)
G generator G1 first generator G2 second generator

Claims (11)

  By mass, C0.06-0.13%, Si0.15% or less, Mn0.1-1.0%, Ni0.005-0.1%, Cr8.5-10.0%, Mo0.05-0 .50%, W 1.0-3.0%, V 0.05-0.30%, Nb 0.02-0.10%, Co 0.5-2.5%, N 0.005-0.035%, B0 .001-0.030% and Al 0.0005-0.006%, (5 × Ni + Mo) is 0.3-0.9%, (100 × C + Cr) is 15.5-20.5%, the balance Is made of martensitic steel made of Fe and inevitable impurities. By mass, C0.06-0.13%, Si0.15% or less, Mn0.1-1.0%, Ni0.005-0.1%, Cr8.5-10.0%, Mo0.05-0 .50%, W 1.0-3.0%, V 0.05-0.30%, Nb 0.02-0.10%, Co 0.5-2.5%, N 0.005-0.035%, B0 .001-0.030% and Al 0.0005-0.006%, (5 × Ni + Mo) is 0.3-0.9%, (100 × C + Cr) is 15.5-20.5%, the balance There is constituted by martensite steel consisting of Fe and unavoidable impurities, 650 ° C., a steam turbine rotor shaft, characterized in that 10 ⁵ hours creep rupture strength of 98 N / mm ² or more. A rotor shaft;
A rotor blade implanted in the rotor shaft;
A stationary blade that guides the inflow of steam into the moving blade and an inner casing that holds the stationary blade,
In the high pressure turbine in which the rotor blade has at least five stages on one side and the first stage is a double flow,
The high-pressure turbine according to claim 1, wherein the rotor shaft is a rotor shaft for a steam turbine according to claim 1. A rotor shaft;
A rotor blade implanted in the rotor shaft;
A stationary blade that guides the inflow of steam into the moving blade and an inner casing that holds the stationary blade,
In the intermediate pressure turbine having a double flow structure in which the rotor blade has six or more stages symmetrically and the first stage is implanted in the center of the rotor shaft,
The intermediate pressure turbine, wherein the rotor shaft is the rotor shaft for a steam turbine according to claim 1 or 2. A rotor shaft;
A rotor blade implanted in the rotor shaft;
A stationary blade that guides the inflow of steam into the moving blade and an inner casing that holds the stationary blade,
The rotor blade has six or more stages and a high-pressure side turbine section into which high-temperature and high-pressure steam generated by a steam generator flows from the center of the rotor shaft, and the rotor blade has five or more stages and the high-pressure side turbine. In the high and intermediate pressure integrated turbine in which the intermediate pressure side turbine portion in which the steam exhausted from the portion and heated by the reheater flows from the central portion of the rotor shaft is coupled to the tandem,
The high- and medium-pressure integrated turbine according to claim 1, wherein the rotor shaft is the rotor shaft for a steam turbine according to claim 1. A rotor shaft;
A rotor blade implanted in the rotor shaft;
A stationary blade that guides the inflow of steam into the moving blade and an inner casing that holds the stationary blade,
In the high pressure turbine in which the rotor blade has at least five stages on one side and the first stage is a double flow,
The rotor shaft is, by mass, C 0.06 to 0.13%, Si 0.15% or less, Mn 0.1 to 1.0%, Ni 0.005 to 0.1%, Cr 8.5 to 10.0%, Mo 0.05 to 0.50%, W 1.0 to 3.0%, V 0.05 to 0.30%, Nb 0.02 to 0.10%, Co 0.5 to 2.5%, N 0.005 to 0 0.035%, B0.001-0.030% and Al 0.0005-0.006%, (5 × Ni + Mo) 0.3-0.9%, (100 × C + Cr) 15.5-20 A high-pressure turbine characterized in that the balance is made of martensitic steel consisting of 5%, the balance being Fe and inevitable impurities. A rotor shaft;
A rotor blade implanted in the rotor shaft;
A stationary blade that guides the inflow of steam into the moving blade and an inner casing that holds the stationary blade,
In the intermediate pressure turbine having a double flow structure in which the rotor blade has six or more stages symmetrically and the first stage is implanted in the center of the rotor shaft,
The rotor shaft is, by mass, C 0.06 to 0.13%, Si 0.15% or less, Mn 0.1 to 1.0%, Ni 0.005 to 0.1%, Cr 8.5 to 10.0%, Mo 0.05 to 0.50%, W 1.0 to 3.0%, V 0.05 to 0.30%, Nb 0.02 to 0.10%, Co 0.5 to 2.5%, N 0.005 to 0 0.035%, B0.001-0.030% and Al 0.0005-0.006%, (5 × Ni + Mo) 0.3-0.9%, (100 × C + Cr) 15.5-20 An intermediate pressure turbine characterized in that it is made of martensite steel consisting of 5%, the balance being Fe and inevitable impurities. A rotor shaft;
A rotor blade implanted in the rotor shaft;
A stationary blade that guides the inflow of steam into the moving blade and an inner casing that holds the stationary blade,
The rotor blade has six or more stages and a high-pressure side turbine section into which high-temperature and high-pressure steam generated by a steam generator flows from the center of the rotor shaft, and the rotor blade has five or more stages and the high-pressure side turbine. In the high and intermediate pressure integrated turbine in which the intermediate pressure side turbine portion in which the steam exhausted from the portion and heated by the reheater flows from the central portion of the rotor shaft is coupled to the tandem,
The rotor shaft is, by mass, C 0.06 to 0.13%, Si 0.15% or less, Mn 0.1 to 1.0%, Ni 0.005 to 0.1%, Cr 8.5 to 10.0%, Mo 0.05 to 0.50%, W 1.0 to 3.0%, V 0.05 to 0.30%, Nb 0.02 to 0.10%, Co 0.5 to 2.5%, N 0.005 to 0 0.035%, B0.001-0.030% and Al 0.0005-0.006%, (5 × Ni + Mo) 0.3-0.9%, (100 × C + Cr) 15.5-20 A high-medium pressure integrated turbine characterized in that it is made of martensite steel consisting of 5%, the balance being Fe and inevitable impurities. In a steam turbine power plant in which a high-pressure turbine, a low-pressure turbine, and a first generator are coupled in tandem, and an intermediate-pressure turbine, a low-pressure turbine, and a second generator are coupled in tandem,
The steam turbine power plant, wherein the high-pressure turbine is the high-pressure turbine according to claim 3 or 6, and the intermediate-pressure turbine is the intermediate-pressure turbine according to claim 4 or 7. In a steam turbine power plant in which a high-pressure turbine, an intermediate-pressure turbine, and a first generator are coupled in tandem, and two low-pressure turbines coupled to the tandem and a second generator are coupled in tandem.
The steam turbine power plant, wherein the high-pressure turbine is the high-pressure turbine according to claim 3 or 6, and the intermediate-pressure turbine is the intermediate-pressure turbine according to claim 4 or 7. In a steam turbine power plant in which a high-medium pressure integrated turbine, a low-pressure turbine, and a generator are connected in tandem,
A steam turbine power plant, wherein the high and medium pressure integrated turbine is the high and medium pressure integrated turbine according to claim 5 or 8.

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