JP2002121654A - Rotor shaft for steam turbine, steam turbine using the same, and steam turbine power plant - Google Patents

Abstract

(57) Abstract: An object of the present invention is to provide a steam turbine rotor shaft having excellent strength at a high temperature and a long time side at a specific temperature of 600 ° C. or more and 50,000 hours or more and a long time. A high-pressure, medium-pressure, high-medium-pressure steam turbine and a steam turbine power plant are provided. SOLUTION: The present invention provides a method for producing C 0.05 to 0.20%, Si
0.2% or less, Mn 0.05 to 1.5%, Ni 0.2% or less, Cr 9.0 to 13.0%, Mo 0.05 to 0.5%, W
0.5 to 5.0%, V 0.05 to 0.30%, Nb 0.01
０0.20%, Co 1.0２2.0%, N 0.01０0.2.
1%, B 0.001 to 0.030% and Al 0.0005 to 0.0
The present invention relates to a steam turbine rotor shaft made of martensite steel containing 0.6% and having a (Ni / Co) ratio of 0.1 or less, and a high-pressure, medium-pressure, high-medium-pressure steam turbine and a steam turbine power plant using the same.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel rotor shaft for a steam turbine, a high-pressure, medium-pressure, high-medium-pressure integrated steam turbine using the same, and a steam turbine power plant using the same, and particularly to an ultra-supercritical thermal power plant. Things.

[0002]

2. Description of the Related Art In recent years, high-temperature and high-pressure thermal power plants have been viewed from the viewpoint of improving efficiency, and the steam temperature of a steam turbine has been increased from the currently highest 600 ° C. to ultimately 65 ° C.
The target is 0 ° C. To increase the steam temperature,
A heat-resistant material with higher high-temperature strength than conventionally used heat-resistant ferrite-based steel is required. Some austenitic heat-resistant alloys have excellent temperature resistance, but have a problem of poor thermal fatigue strength due to a large coefficient of thermal expansion.

[0003] For this reason, examples of new ferritic heat-resistant steels having improved high-temperature strength include JP-A-4-147948, JP-A-9-296258 and JP-B-8-30249. As a steam turbine power plant, JP-A-7-233
Japanese Patent Application Publication No. 704 and Japanese Patent Application Laid-Open No. 11-93603 are known.

[0004]

SUMMARY OF THE INVENTION However, 650
In order to achieve the ultimate steam temperature of ℃, these proposed alloys contain a lot of W and Co, so that they form brittle intermetallic compounds on the long-term side and lower the long-term creep rupture strength. Therefore, development of a ferrite heat-resistant steel which is still insufficient and has high strength at high temperatures and stable strength for a long time has been desired.

SUMMARY OF THE INVENTION An object of the present invention is to provide a steam turbine rotor shaft having excellent strength at a high temperature and a long time side at a specific temperature of 600 ° C. or more and 50,000 hours or more, and a high pressure, a medium pressure, and a high and medium pressure. A high pressure steam turbine and a steam turbine power plant are provided.

[0006]

SUMMARY OF THE INVENTION The present invention provides a C
0.05-0.20%, Si 0.2% or less, Mn 0.01-
1.5%, Ni 0.01 to 1.0%, Cr 9.0 to 13.0
%, Mo 0.05-0.5%, W 0.5-5.0%, V0.0
5 to 0.30%, Nb 0.01 to 0.20%, Co 1.0 to
2.0%, N 0.01-0.1%, B 0.001-0.03
0% and 0.0005-0.006% Al, or in the foregoing, 0.2% or less of Ni and 0.5-10.0% of Co.
% And a (Ni / Co) ratio of 0.15 or less, preferably a martensitic steel having a balance of substantially Fe.

[0007] The present invention relates to a method for preparing C05-0.20 by weight.
%, Si 0.2% or less, Mn 0.01-1.5%, Ni 0.2%
01-1.0%, Cr 9.0-13.0%, Mo 0.05-
0.5%, W 0.5-5.0%, V 0.05-0.30%, N
b 0.01 to 0.20%, Co 0.5 to 10.0%, N
0.01-0.1%, B 0.001-0.030% and Al
A steam turbine comprising 0.0005 to 0.006% and a martensitic steel having a (Ni / Co) ratio of 0.09 or less, preferably a martensitic steel having a balance substantially of Fe. On the rotor shaft.

[0008] The present invention relates to C0.05 to 0.20 by weight.
%, Si 0.2% or less, Mn 0.01-1.5%, Ni
0.2% or less, Cr 9.0-13.0%, W0.5-5.0
%, V 0.05 to 0.30%, Nb 0.01 to 0.20
%, Co 1.0 to 2.0 and B 0.001 to 0.030%
And 0.0005-0.006% of Al and (Ni /
(Co) ratio is in a martensitic steel having a ratio of 0.2 or less, preferably a martensitic steel having a balance substantially of Fe.

According to the present invention, C0.05 to 0.20 by weight is used.
%, Si 0.2% or less, Mn 0.01-1.5%, Ni
0.01 to 1.0%, Cr 9.0 to 13.0%, W0.5
５5.0%, V 0.05 ３０0.30%, Nb 0.01〜0.0.
20%, Co 0.5-10.0% and B 0.001-0.
030%, preferably 0.0005 to Al.
Made of martensitic steel containing 0.006%, 650
This is a steam turbine rotor shaft having a creep rupture strength of 10.5 kg / mm ² or more at 100 ° C. for 100,000 hours.

[0010] The present invention has a rotor shaft, a moving blade implanted on the rotor shaft, a stationary blade for guiding the flow of steam to the moving blade, and an inner casing holding the stationary blade; A high-pressure steam turbine in which the rotor blades are at least five stages on one side and the first stage is implanted in a double flow structure at the center, and the rotor blades have six or more stages each in a symmetrical manner, and the first stage is implanted at the center of the rotor shaft. An intermediate-pressure steam turbine having a double-flow structure provided, or the steam coming out of a high-pressure turbine into which high-temperature and high-pressure steam flows from a central portion of the rotor shaft is heated to be heated from a central portion of the rotor shaft to an intermediate-pressure turbine. In any one of the high- and medium-pressure steam turbines having the high-pressure turbine blades that flow in at least six stages and the medium-pressure turbine blades that have five or more stages, the rotor shaft has a rotor shaft having the above-described composition. , Or by weight, C0.05~0.20
%, Preferably 0.09 to 0.15%, Si 0.2% or less, preferably 0.15% or less, Mn 0.01 to 1.5.
%, Preferably 0.1-0.7%, more preferably 0.1%.
35 to 0.65%, Ni 0.005 to 0.15%, preferably 0.01 to 0.06%, Cr 9.0 to 13.0%,
Preferably 9.5 to 11.5%, Mo 0.05 to 2.0
%, Preferably 0.05 to 0.4%, W 0.5 to 5.0
%, Preferably 1.0 to 3.0%, V 0.05 to 0.30
%, Preferably 0.15 to 0.30%, Nb 0.01 to
0.20%, preferably 0.04 to 0.13%, Co
1.0-2.0%, preferably 1.1-1.8%, N
0.01-0.1%, preferably 0.01-0.04%,
B 0.001 to 0.030%, preferably 0.005 to
It is characterized by being made of a specific martensitic steel containing 0.025% and Al 0.0005 to 0.006%.

C is an indispensable element for securing hardenability and for increasing the high-temperature strength by precipitating M ₂₃ C ₆ type carbide during the tempering process, and requires at least 0.05%.
It exceeds 0.20%, the excessive precipitation of M ₂₃ C ₆ type carbide, since impair the high-temperature strength of the rather long side lowering the matrix of, limited to 0.05 to 0.20%. Desirably, it is 0.1 to 0.15%.

Mn suppresses the formation of δ ferrite,
_At least 0.0 as an element that promotes precipitation of ₂₃ C ₆ type carbide
1% is necessary, but if it exceeds 1.5%, the oxidation resistance deteriorates. Therefore, the content is limited to 0.01 to 1.5%. Preferably, it is 0.1 to 0.7%. More preferably, 0.3.
5 to 0.65%.

Ni is an element that suppresses the formation of δ ferrite and imparts toughness, and requires at least 0.005%. However, the ratio of (Ni / Co) between Co and Ni is specified to be 0.09 or less. With respect to the relationship, 1.0% or less can be contained. However, however, for ratios less than 0.15, 0.2
%, The long-term creep rupture strength of 600 ° C. or more and 50,000 hours or more is reduced, so 0.2% or less, preferably 0.005 to 0.15%, more preferably 0.01 to 0.0%.
6%. In particular, lowering with Co improves the long-term creep rupture strength of 100,000 hours or more.

Cr is an essential element for imparting oxidation resistance and increasing the high-temperature strength by precipitating M ₂₃ C ₆ type carbides. A minimum of 9% is required. Therefore, the content is limited to 9.0 to 13.0% because it forms and lowers the high-temperature strength and toughness. Preferably, 9.5 to 1
It is 1.5%, more preferably 10.0 to 11.0%.

Mo has the effect of promoting the fine precipitation of M23C6 type carbides and hindering agglomeration. Therefore, Mo is effective for maintaining high-temperature strength for a long time, and at least 0.05% is required.
When the content is 2.0% or more, δ ferrite is easily generated, so the content is limited to 0.05 to 2.0%. Preferably, 0.05
To 0.5%, more preferably 0.1 to 0.3%.

W is more effective than Mo in suppressing the coarsening of M ₂₃ C ₆ -type carbides, and is effective for improving the high temperature strength by solid solution strengthening of the matrix.
It is necessary, but if it exceeds 5.0%, δ-ferrite and Laves phases tend to be formed, and conversely, the high-temperature strength decreases. Desirably, it is 1.0 to 3.0%.

V is effective for precipitating carbonitrides of V to increase the high-temperature strength, and requires at least 0.05%.
Exceeding 0.3% excessively fixed carbon when, limited to 0.05 to 0.3% as it reduces the high temperature strength in the opposite by subtracting the amount of precipitated M ₂₃ C ₆ type carbide. Preferably, 0.10
0.30%.

At least one of Nb and Ta is Nb
Generates C and TaC to help refine crystal grains, and partially dissolves during quenching to form NbC and TaC during tempering.
Has the effect of increasing the high-temperature strength and has a minimum of 0.01.
However, if it exceeds 0.20%, as in the case of V, carbon is excessively fixed to reduce the amount of M ₂₃ C ₆ type carbide,
Since the high-temperature strength is reduced, the content is limited to 0.01 to 0.20%. Desirably, it is 0.04 to 0.13%.

Co is an important element which distinguishes the present invention from the prior art. In the present invention, the ratio of (Ni / Co) to Ni is set to 0.05 to 10.0% in a specific relationship of 0.09 or less, and 0.1 to 0.1%.
For a ratio of 5 or less, the long-time high-temperature strength of 600 ° C. or more and 50,000 hours or more can be remarkably improved by adding 1.0 to 2.0% of Co. This is considered to be due to the interaction with W, and is a characteristic phenomenon in the alloy of the present invention containing W at 0.5% or more. For the latter ratio, Co is 2.0
% Is not preferred because the long-term strength decreases. Desirably, it is 1.1 to 1.8%. Furthermore,
Co improves the creep rupture strength by lowering it with Ni. All of them are austenite stabilizing elements and promote the precipitation and make the long-term side unstable. Both are reduced and the (Ni / Co) ratio is set to 0.15
The most excellent long-term stability is shown below. In particular, 0.1 or less is most suitable. However, if these are made too low, delta ferrite will be formed, so that C is made high.

N acts to precipitate nitride of V and increase the high-temperature strength by IS effect (interaction between interstitial solid solution element and substitutional solid solution element) in cooperation with Mo and W in a solid solution state. At least 0.01% is necessary, but if it exceeds 0.1%, the ductility is reduced. Therefore, the content is limited to 0.01 to 0.1%. Desirably, it is 0.01 to 0.04%.

Since Si promotes the generation of a Laves phase and lowers ductility due to grain boundary segregation and the like, it is limited to 0.15% or less. Desirably, it is 0.10% or less. However, when Si is added as a deoxidizing agent in an extremely small amount of 0.03% or more, good high-temperature characteristics can be obtained in relation to Al deoxidation described later.

Al is added in an amount of 0.0005% or more as a deoxidizing agent and a grain refiner. However, Al is a strong nitride-forming element, and by fixing nitrogen effectively acting on creep, particularly when the content exceeds 0.006%, 625 ° C. to 7
It has the effect of lowering the long-term creep strength of 50,000 hours or more in a high temperature range such as 00 ° C. Further, Al promotes the precipitation of the Laves phase, which is a brittle intermetallic compound mainly composed of W, causing precipitation at crystal grain boundaries and lowering the creep rupture strength on the long-time side. In particular, the Laves phase continuously precipitates at the grain boundaries in extremely fine grain refinement. Therefore, the upper limit is made 0.006%. More preferably 0.0
01 to 0.004%. In particular, the effect is significant when the W is as high as 1.5 to 3.0%.

B has a grain boundary strengthening action and forms a solid solution in 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 is effective when added minimum 0.001%, so detrimental to weldability and forgeability exceeds 0.030% Limited to 0.001 to 0.030%.
Desirably, it is 0.005 to 0.025%.

The chromium equivalent determined by the following equation is 4 to
It is preferably 10.5, particularly preferably 6.5 to 9.5. Chromium equivalent = -40C (%)-30N (%)-2Mn
(%)-4Ni (%) + Cr (%) + 6Si (%) +
4Mo (%) + 1.5W (%) + 11V (%) + 5Nb
(%) + 2.5Ta (%)-2Co (%)-2Co
(%) The rotor shaft of the present invention is formed by casting an ingot by vacuum melting, vacuum C deoxidation, and ESR melting, and forging.
Heat at 900-1150 ° C, 50-600 ° C at center hole
/ H cooling, followed by primary tempering at 500-620 ° C and secondary tempering at a higher temperature of 600-750 ° C.

The present invention relates to a steam turbine power plant in which a high-pressure turbine, a medium-pressure turbine and one or two low-pressure turbines are connected in tandem or cross, or a high-pressure turbine, a low-pressure turbine and a generator, and a medium-pressure turbine and a low-pressure turbine. And a generator in a tandem steam turbine power plant, wherein the high-pressure turbine and the medium-pressure turbine comprise at least one of the high-pressure turbine and the medium-pressure turbine described above, and the rotor shaft thereof is any one of the above-described ones. The steam turbine rotor shaft described in any one of the above.

In the steam turbine power plant according to the present invention, the high-pressure turbine and the intermediate-pressure turbine or the high-to-medium pressure turbine have a steam inlet temperature to the first stage rotor blade of 593 to 660.
° C (593-605 ° C, 610-620 ° C, 620-6
30 ° C., 630-640 ° C.), and a pressure of 250 kgf / cm ² or more (preferably 246-316 kgf / cm ^2).
A cm ²⁾ or 170~200kgf / cm ^2, 10 ⁵ h creep rupture strength at temperatures of at least the first stage corresponding to each steam temperature of the rotor shaft or rotor shaft and blades and vanes are 10.5kgf / mm ² or more (preferably 17 kgf / mm ² or more) Cr9～13 wt% of above (preferably 10.5 to 11.5 wt%) high-strength martensitic steel having a fully tempered martensite structure containing Is preferred. The low-pressure turbine preferably has a steam inlet temperature to the first-stage bucket in a range of 350 to 400 ° C. Further, it is preferable that the first stage, the second stage, or up to the third stage of the rotor blade is made of a Ni-based alloy.

(1) The high-pressure steam turbine according to the present invention comprises:
The rotor blade has 7 stages or more, preferably 9 stages or more, preferably 9 to 12 stages, and the first stage has a double flow, and the rotor shaft has a bearing center distance (L) of 5000 mm or more (preferably 5100 to 6500 mm). Is preferred. The wing length is preferably 25 to 180 mm from the first stage to the last stage.

(2) The medium-pressure steam turbine according to the present invention
The rotor blade has a double flow structure in which each rotor blade has six or more stages, preferably six to nine stages, and the first stage is implanted in the center of the rotor shaft, and the rotor shaft has a bearing center distance (L). Is 5000 mm or more (preferably 5100 to 650
0 mm) is preferred. The wing length is preferably 60 to 300 mm.

(3) In the high-to-medium pressure integrated steam turbine according to the present invention, the high-pressure-side moving blade has 7 stages or more, preferably 8 or more stages, and the medium-pressure side moving blade has 5 or more stages, preferably 6 or more stages, The rotor shaft has a bearing center distance (L) of 600.
It is preferably 0 mm or more (preferably 6100 to 7000 mm).
The wing length is 25-200 mm on the high pressure side, and 100-
350 mm is preferred.

(4) The rotor shaft of the high-pressure, medium-pressure and high-medium-pressure turbine according to the present invention has a fully tempered martensite structure having the above-described composition, in order to obtain high high-temperature strength, low-temperature toughness, and high fatigue strength. It is preferable to adjust the Cr equivalent to 4-8.

(5) In the high-pressure, medium-pressure or high-medium-pressure integrated steam turbine rotor shaft according to the present invention, it is preferable that a build-up weld layer of Cr-Mo low alloy steel having high bearing characteristics is formed on the journal portion thereof. Forming the overlay welding layer of any number of preferably 3 to 10 layers using a welding material,
The amount of Cr in the welding material from the first layer to any of the second to fourth layers is sequentially reduced, and
Welding is performed using a welding material made of steel having an amount of Cr, the amount of Cr of the welding material used for welding the first layer is reduced by about 2 to 6% by weight from the amount of Cr of the base material, and The Cr content is adjusted to 0.5 to 3% by weight (preferably 1 to 2.5% by weight).

In the present invention, overlay welding is preferred for improving the bearing characteristics of the journal portion in terms of the highest safety. However, shrink-fitting of a sleeve made of a low alloy steel having a Cr content of 1 to 3%, It is also possible to adopt a structure to be fitted.

In order to increase the number of welding layers and gradually reduce the Cr content, three or more layers are preferred, and even more than ten layers cannot be welded further. As an example, about 18 in the final finish
mm thickness is required. In order to form such a thickness, at least five build-up weld layers are preferable even if the final finishing allowance by cutting is excluded. 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 fourth and subsequent welding layers is C0.
01-0.1%, Si 0.3-1%, Mn 0.3-1.5%,
Cr 0.5 to 3%, Mo 0.1 to 1.5%, the balance Fe
Is preferred.

(6) Inner casing control valve box, combined reheat valve box, main steam reed pipe, main steam inlet pipe, reheat inlet pipe, high pressure turbine of high pressure turbine, medium pressure turbine and high and medium pressure turbine of the present invention Martensitic heat-resistant steel constituting 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 is preferable.

The super-supercritical turbine high-pressure, medium-pressure or high-medium-pressure inner casing of 250 kgf / cm ² or more, and the main steam stop valve and the control valve casing have a temperature dependent on their operating temperature.
10 ⁵ h Creep rupture strength of 9 kgf / mm ² or more and room temperature impact absorption energy of 1 kgf-m or more are preferable.

(7) As the internal casing material of the high-pressure turbine, the intermediate-pressure turbine and the high-to-medium pressure turbine of the present invention, the creep rupture strength at 10 ⁵ hours at a temperature corresponding to each steam temperature is 10 kgf / mm ² or more (preferably, 10.5kgf / mm
² or more), which is a martensitic cast steel containing 8 to 9.5% by weight of Cr. The specific composition is, by weight, C
0.06 to 0.16% (preferably 0.09 to 0.14%)
%), N 0.01 to 0.1% (preferably 0.02 to 0.0%)
6%), Mn 1% or less (preferably 0.4 to 0.7%), S
i not added or 0.5% or less (preferably 0.1 to 0.4%)
%), V 0.05 to 0.35% (preferably 0.15 to 0.2%)
5%), Nb 0.15% or less (preferably 0.02 to 0.1)
%), Ni 0.2 to 1% (preferably 0.4 to 0.8)
%), Cr 8 to 12% (preferably 8 to 10%, more preferably 8.5 to 9.5%), W1 to 3.5%, Mo1.5.
% (Preferably 0.4 to 0.8%) and the balance Fe is preferably a martensitic cast steel. W amount is 620 ° C
1.0-1.5% at 630 ° C, 1.6-2.0%, 64
2.1-2.5% at 0 ° C, 2.6-2.5% at 650 ° C
It is preferably 3.0% and 3.1-3.5% at 660 ° C.

The addition of Ta, Ti and Zr has an effect of increasing the toughness, and a sufficient effect can be obtained by adding Ta 0.15% or less, Ti 0.1% or less and Zr 0.1% or less alone or in combination. When 0.1% or more of Ta is added, N
The addition of b can be omitted.

(8) The low-pressure steam turbine according to the present invention comprises:
The rotation speed is 3000 rpm or 3600 rpm, the rotor blades have left-right symmetrical 5 or more stages, preferably 6 or more stages, more preferably 8 to 10 stages, and a double flow in which the first stage is implanted at the center of the rotor shaft. The rotor shaft has a bearing center distance (L) of 6500 mm or more (preferably 6600 to 7500 mm). The length of the wing portion is preferably 90 mm or more at the first stage, and the length at the last stage is as described above. The rotor shaft has a 0.02% proof stress of room temperature of 80% at the center in the rotor shaft.
kg / mm ² or more, 0.2% proof stress is 87.5 kg / mm ² or more, tensile strength is 92 kg / mm ² or more, FATT is -5 ° C. or less, or 20 ° C. V notch impact value is 10 kg · m / cm ^2. It is preferable to use the bainite steel described above.

The last stage blade of the low-pressure steam turbine is made of Ti-based alloy or 17-4PH, 12% Cr-based martensitic steel, and has high tensile strength to withstand high centrifugal force and vibration stress due to high speed rotation. At the same time, high cycle fatigue strength must be high. Ti-based alloys are Al3-8
% And V3 to 6%, and subjected to aging treatment. Also, the latter 12% martensitic steel has a harmful δ
The presence of ferrite significantly reduces the fatigue strength, so the composition is adjusted so that the Cr equivalent calculated by the above-described equation as a fully tempered martensite structure is 10 or less, preferably 4 to 10, and the δ ferrite phase is After melting and forging, as a heat treatment heat treatment, 1000 ° C. to 1100 ° C. (preferably 1000 to
1055 ° C.), preferably after quenching for 0.5 to 3 hours, rapidly quenching to room temperature (especially oil quenching is preferable), and then tempering at 540 to 620 ° C.
Primary tempering, in which the temperature is maintained at 570 ° C. for preferably 1 to 6 hours and then cooled to room temperature, and secondary tempering in which the temperature is maintained at 560 ° C. to 590 ° C., preferably for 1 to 6 hours and then cooled to room temperature.
It is preferable that tempering heat treatment is performed more than once. The secondary tempering temperature is preferably higher than the primary tempering temperature,
It is particularly preferable to raise the temperature by 10 to 30 ° C.
It is preferable to increase the temperature by 0 ° C. Further, in order to completely decompose the retained austenite, it is preferable to perform a deep cooling process of cooling to a temperature of dry ice or liquid nitrogen.

In particular, as a 12% martensite steel,
C 0.14 to 0.40%, preferably 0.19 to 0.4
0%, Si 0.5% or less, Mn 1.5% or less, Ni2
3.5%, Cr 8-13%, Mo 1.5-4%, at least one of Nb and Ta, 0.02-0.3%, V0.
Those containing 0.05 to 0.35% and 0.04 to 0.15% of N are preferable. From C0.20 to 0.40% and Mo
1.5-3.5% or C 0.14-0.19% and Mo
Combinations containing 2.0-3.5% are preferred.

The final stage blade length of the low pressure turbine is 360
882 mm (35.8 ") for 95 rpm, 952.
5mm (37.5 "), 1016mm (40"), 1067mm
(42 ") and 1092 mm for 3000 rpm
(43 "), 1168.4 mm (46"), 1219.2 mm
(48 ") and 1270 mm (50").

It is preferable that an erosion prevention layer made of a Co-based alloy is provided on the leading edge portion of the tip of the last stage rotor blade. Co-based alloy is Cr25-30 by weight
%, W 1.5 to 7.0%, and C 0.5 to 1.5% are preferably joined by electron beam or TIG welding.

In the last stage blade of the low-pressure steam turbine, the inclination in the width direction of the blade portion is substantially parallel to the axial direction of the rotating shaft near the implanted portion, and the tip of the blade portion is preferably 65 to 65 in the axial direction. It is inclined at 85 degrees, more preferably at 70 to 80 degrees. Fork type whose wing length is 43 inches or more for 3000 rpm or 37.5 inches or more for 3600 rpm, and the implant portion is 9 or more for 43 inches or more and 7 or more for 37.5 inches or more It is preferable to use an inverted Christmas tree type having four or more projections. The width of the implanted portion relative to the width of the wing tip is 2.1 to 2.1.
It is preferably 2.5 times. An erosion prevention shield portion is provided on the leading side of the tip of the wing portion, the implantation portion 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 the same as the wing portion side. It is preferably larger than the opposite side.

(9) The low-pressure steam turbine rotor shaft is C-0.2-0.3%, Si-0.15% or less, and Mn-0.2.
25% or less, Ni 3.25 to 4.5%, Cr 1.6 to 2.5
%, Mo 0.25 to 0.6%, V 0.05 to 0.25%, and a low alloy steel having a total tempered bainite structure of 92.5% or more of Fe is preferable. Preferably, it is manufactured by a similar manufacturing method. In particular, a Si content is 0.05% or less, Mn 0.1% or less, and a raw material in which impurities such as P, S, As, Sb, and Sn are reduced as much as possible, and a total amount is 0.025% or less, preferably 0.015%. %
It is preferable to use a super-clean production using a raw material having a small amount of impurities as described below. P and S each 0.010% or less, Sn and As 0.00
It is preferably 5% or less and Sb 0.001% or less. This rotor shaft has a proof stress of 0.02% at room temperature at the center.
kg / mm ² or more, 0.2% proof stress is 87.5 kg / mm ² or more, tensile strength is 92 kg / mm ² or more, FATT is -5 ° C. or less, or 20 ° C. V notch impact value is 10 kg · m / cm ^2. The bainite steel described above is preferable. For the rotor shaft according to the present invention, it is preferable to provide a fork type rotor blade having a center hole for a rotor shaft having a center hole, and an inverted Christmas tree type rotor blade for a rotor shaft having no center hole.

(10) Other than the last stage of the low pressure turbine blade and the nozzles, C is 0.05 to 0.2%, and Si is 0.1 to 0.1%.
0.5%, Mn 0.2-1.0%, Cr 10-13%, Mo
A fully tempered martensitic steel having 0.04 to 0.2% is preferred.

(11) Both the inner and outer casings for the low-pressure turbine have C of 0.2 to 0.3%, Si of 0.3 to 0.7%,
A cast carbon steel having Mn of 1% or less is preferred.

(12) The main steam stop valve casing and the steam control valve casing are C 0.1-0.2%, Si 0.1-0.1%.
4%, Mn 0.2-1.0%, Cr 8.5-10.5%, M
o 0.3 to 1.0%, W 1.0 to 3.0%, V 0.1 to 0.1
3%, Nb 0.03 to 0.1%, N 0.03 to 0.08%,
A fully tempered martensitic forged steel containing 0.0005% to 0.003% B is preferred.

(13) The high pressure turbine, the medium pressure turbine, and the outer casing for the high / medium pressure turbine have C0.10-0.2.
0%, Si 0.05-0.6%, Mn 0.1-1.0%, N
i 0.1 to 0.5%, Cr 1 to 2.5%, Mo 0.5 to 1.
5%, V0.1-0.35%, preferably Al0.1.
025% or less, B 0.0005 to 0.004% and Ti
Preferably, it is manufactured from cast steel containing at least one of 0.05 to 0.2% and having a fully tempered bainite structure. In particular, C 0.10 to 0.18%, Si 0.20 to 0.6%
0%, Mn 0.20 to 0.50%, Ni 0.1 to 0.5%,
Cr 1.0-1.5%, Mo 0.9-1.2%, V0.2-
0.3%, Al 0.001 to 0.005%, Ti 0.045 to
Cast steel containing 0.10% and 0.0005-0.0020% B is preferred. More preferably, the Ti / Al ratio is 0.5-0.5.
It is 10.

(14) First-stage blades of high-pressure, medium-pressure and high-medium-pressure turbines (high-pressure side and medium-pressure side) at a steam temperature of 610 to 650 ° C., preferably up to two or three stages on the high-pressure side of the high-pressure turbine and high-medium-pressure turbine On the medium pressure side of the intermediate pressure turbine and the high intermediate pressure turbine, up to the second stage are replaced with the above-mentioned martensitic steel by weight, and are C 0.03 to 0.20% (preferably 0.03 to 0.15%), Cr 12 to 20%, Mo9 ~ 2
0% (preferably 12 to 20%), Co 12% or less (preferably 5 to 12%), Al 0.5 to 1.5%, Ti1 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% or less A Ni-based alloy containing at least one kind can be used. The following of the content of each element includes 0%. The Ni-based alloy is subjected to a solution treatment and an aging treatment after the melt forging.

[0050]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Example 1 A 50 kg steel ingot was melted using a high frequency melting furnace and hot forged. The test was performed at a temperature of 1150 ° C. or less in order to prevent forging cracks. After annealing the forged steel, the steel was heated to 1050 ° C. and quenched by simulating the rotor shaft (water spray cooling was performed on the actual rotor shaft).
Tempering was performed at 40 ° C. to produce a creep rupture test piece. Table 1 shows the chemical components (% by weight) of the steel ingot. No. 1
Is a comparative material, 2 and 3 are the materials of the present invention.

[0051]

[Table 1]

Table 2 shows the creep rupture strength at 650 ° C. of the test materials. As shown in the table, the content of Al exceeding 0.006% should be reduced to less than the specific composition of the present invention, as it significantly lowers the creep rupture strength. In addition, No. 2% Co for 1 comparative material
In the case of No. 2 where Ni was reduced to 0.2% or less. For Nos. 2 and 3, the creep rupture strength was 10.5 k for the long side of 100,000 hours.
g / mm ² or more, and the smaller the (Ni / Co) ratio is 0.034 or 0.0067, which is 0.09 or less, the better the creep rupture strength is on the longer time side. I understand.

[0053]

[Table 2]

The rotor shaft in this embodiment is used in a high-pressure turbine, an intermediate-pressure turbine or a high-intermediate-pressure integrated steam turbine in which a high-pressure section and an intermediate-pressure section are integrated, in which the steam temperature inlet temperature to the first stage rotor blade is 600 ° C. or more. Can be. These steam turbines are rotor shafts having double-flowing blade implants that flow outward in opposite directions. Further, a cladding of Cr-Mo low alloy steel having a bainite structure or a sleeve thereof is provided on the journal portion of each rotor shaft. In particular, in this embodiment, the high pressure turbine 600 ° C., the medium pressure turbine 620 ° C.,
Alternatively, it is suitable for an ultra-supercritical power plant with a single-unit output of 1000 MW or more using a high-pressure turbine and a medium-pressure turbine with a steam temperature of 620 ° C. Furthermore, application to 630 to 650 ° C. as these steam temperatures is possible.

[Embodiment 2] Table 3 shows the main specifications of a steam turbine of 625 ° C and 1050 MW according to the present invention. In the present embodiment, the blade length of the last stage rotor blade in a cross-compound type four-flow exhaust, low-pressure turbine is 43 inches, and the turbine configuration A is 3000 HP-IP and two LPs.
r / min, turbine configuration B is HP-LP and IP-LP
Have the same number of revolutions of 3000 r / min, HP,
For the rotor shaft exposed to the high temperature of IP, the high strength 12Cr steel of the present invention shown in Table 4 based on the results obtained in Example 1 is used. The steam temperature of the high pressure section (HP) is 625 ° C,
At a pressure of 250 kgf / cm ² , the steam temperature in the intermediate pressure part (IP) is heated to 625 ° C. by a reheater, and is 45 to 65 kg.
It is operated at a pressure of f / cm ² . The low pressure part (LP) enters at a steam temperature of 400 ° C. and is sent to the condenser at a temperature of 100 ° C. or less and a vacuum of 722 mmHg.

The sum of the distance between the bearings in which the high-pressure turbine and the intermediate-pressure turbine are connected in tandem and the distance between the bearings of the two low-pressure turbines in tandem are approximately 31.5 m, which is compact.

[0057]

[Table 3]

FIG. 1 is a cross-sectional view of a structure in which the high-pressure and medium-pressure steam turbines in the turbine configuration A in Table 3 are tandem-coupled.

(High-Pressure Steam Turbine) In the drawing, the high-pressure steam turbine on the left side is provided with a high-pressure axle 23 having high-pressure moving blades 16 implanted in a high-pressure inner casing 18 and a high-pressure outer casing 19 outside thereof. The high-temperature and high-pressure steam passes through the main steam pipe and passes through the main steam inlet 2 from the flange and the elbow 25 constituting the main steam inlet.
8 and is guided from the nozzle box 38 to the first-stage double-flow blade. The first stage has a double flow, and eight stages are provided on one side. A stationary blade is provided for each of these moving blades. The moving blade is a saddle type dove-til type, double tinon, and the first stage blade length is about 35 mm. The length between the axles is about 5.3 m, and the diameter of the smallest part corresponding to the stationary blade part is about 710 mm, and the ratio of the length to the diameter is about 8.2.

The materials shown in Table 4 to be described later are used for the first stage blade and the first stage nozzle, and the other blades and nozzles are all made of 12% Cr-based steel containing no W, Co and B. The length of the wing of the rotor blade is 35 ~
The length from the second stage to the final stage is 65 to 180 mm depending on the output of the steam turbine, and the number of stages is 9-1.
In two stages, the length of the wings in each stage is 1.10 to 1.15, which is the length adjacent to the upstream side on the downstream side, and the ratio gradually increases on the downstream side. Has become.

(Medium Pressure Steam Turbine) In the figure, the medium pressure steam turbine on the right rotates the generator discharged together with the high pressure steam turbine by the steam heated from the high pressure steam turbine to 625 ° C. again by the reheater. Thing, 30
It is rotated at a rotation speed of 00 times / min. The medium-pressure turbine has a medium-pressure inner second casing 21 and a medium-pressure outer casing 22 similarly to the high-pressure turbine. The moving blade 17 has a double flow in six stages, is provided in a structure which is substantially symmetrical with respect to the longitudinal direction of the medium pressure axle, and has a first stage blade length of about 100 mm and a last stage blade length of about 230 mm. The first and second dovetails are inverted Christmas tree types.
The diameter of the rotor shaft corresponding to the stationary blade before the last stage rotor blade is about 630 mm, which is about 9.2 times the distance between bearings of 5.8 m.

In this embodiment, W and Co were used except that the materials shown in Table 4 described later were used for the first stage blade and the first stage nozzle.
And 12% Cr-based steel containing no B is used. The length of the blade portion of the rotor blade in this embodiment is longer at each stage from the first stage to the last stage, and the length from the first stage to the last stage is 60 to 300 mm depending on the output of the steam turbine.
In the 9th to 9th stages, the length of the wing portion in each stage is longer at a ratio of 1.1 to 1.2 as the length of the downstream side is adjacent to the upstream side.

The rotor shaft has a diameter that is larger than that of the portion corresponding to the stationary blade in which the moving blade is implanted. The axial width of the rotor shaft increases as the blade length of the moving blade increases. The ratio of the width to the blade length of the rotor blade is 0.35 to 0.8 from the first stage to the last stage, and gradually decreases from the first stage to the last stage.

The first stage turbine blades of the high pressure turbine have saddle type implants, and the turbine blades of the second and subsequent stages of the high pressure turbine and all stages of the medium pressure turbine are inverted Christmas tree types.

(Low-Pressure Steam Turbine) FIG. 2 is a sectional view of the low-pressure turbine. The low pressure turbine is connected in two tandems and has almost the same structure. Each of the moving blades 41 has eight stages on the left and right sides and is substantially symmetrical on the left and right sides, and stationary blades 42 are provided corresponding to the moving blades. The nozzle box 45 is of a double flow type.

The rotor shaft 44 has a weight of C0.2
~ 0.3%, Si 0.03-0.1%, Mn 0.1-0.2%, P0.01% or less, S0.01% or less, Ni 3.5-4.5%, Cr 1.8-2.5%,
Mo 0.3-0.5%, V 0.1-0.2%, Al 0.01% or less, Sn
A super-cleaned tempered bainite forged steel containing 0.005% or less, As 0.005% or less, and Sb 0.001% or less is used. These steels are 840 ° C x 3 hours after hot forging.
After heating, quenching after cooling at 100 ° C / h, 575 ° C x
Tempering by heating for 32 hours is performed, and has a fully tempered bainite structure. 0.02% yield strength 80 kg / mm ² or more, 0.2%
Strength 87.5kg / mm ² or more, a tensile strength of 100 kg / mm ² or more, V notch impact value 10 kg-m or more, FATT -20
° C or less, and had high strength and high toughness, and could be implanted with a blade length of 43 to 50 inches as the last stage rotor blade of this example.

The 43 inch wing of this embodiment has C0.14
%, Si 0.04%, Mn 0.15%, Cr 11.5
%, Ni 2.60%, Mo 2.30%, V 0.27%,
Quenching and tempering were performed using martensitic steel containing 0.10% of Nb and 0.07% of N. This product has a tensile strength of 134 kg / mm ² and a V-notch impact value of 5.0 k.
g-m / cm ² .

The rotor blades and stationary blades other than the last stage have M
A 12% Cr steel containing 0.1% of o is used. 0.25% cast steel is used for the inner and outer casing materials.
The center-to-center distance of the bearing 43 in this embodiment is 7500 mm
And the diameter of the rotor shaft corresponding to the stationary blade portion is about 128
0 mm, and the diameter at the blade implantation part is 2275 mm.

The erosion shield for preventing erosion due to water droplets in steam has a weight of C1.0.
%, Cr 28.0%, and W 4.0%, a stellite plate of a Co-based alloy was joined by electron beam welding. In this embodiment, the continuous cover is formed by cutting after forging of the whole. Incidentally, the continuous cover can also be formed mechanically integrally.

In the low-pressure turbine of this embodiment, the axial width of the moving blade implantation portion is from the first stage to the third stage, the fourth stage, the fifth stage, the sixth stage, the seventh stage and the eighth stage.
The width gradually increases in four stages, and the width of the last stage is about 2.5 times larger than the width of the first stage.

The diameter of the portion corresponding to the stationary blade portion is reduced, and the axial width of the portion is gradually increased in three stages of the fifth, sixth, and seventh stages from the first stage blade side. The width of the last stage is about 1.
9 times larger.

The implanted portion of the moving blade has a diameter larger than that of the portion corresponding to the stationary blade, and the implant width is larger as the blade length of the moving blade is larger. The ratio of the width to the blade length of the rotor blade is 0.1 in the first stage to the last stage.
15 to 0.19, and gradually decreases from the first stage to the last stage.

The width of the rotor shaft corresponding to each stationary blade is gradually increased in each stage from the first stage and the second stage to the last stage and the front stage. The ratio of the width to the blade length of the rotor blade is 0.25 to 1.25, and decreases from upstream to downstream.

Two low pressure turbines are connected in tandem,
The total distance between the bearings is about 18.3 m, and the ratio of the total distance between the bearings of the two low pressure turbines connected in tandem to the blade length of the last stage rotor blade of the low pressure turbine is 1.
6.7.

This embodiment is also applicable to a 1000 MW class large-capacity power plant in which the steam inlet temperatures to the high-pressure steam turbine and the medium-pressure steam turbine are 610 ° C. and the steam inlet temperatures to the two low-pressure steam turbines are 385 ° C. Configuration.

(Power Generation Plant) The power generation plant in this embodiment is mainly composed of a coal-fired boiler, a high-pressure turbine, a medium-pressure turbine, two low-pressure turbines, a condenser, a condensate pump,
It consists of a low-pressure feed water heater system, a deaerator, a booster pump, a feed water pump, and a high-pressure feed water heater system. The ultra-high-temperature and high-pressure steam generated in the boiler enters a high-pressure turbine to generate power, is reheated again by the boiler, and enters a medium-pressure turbine to generate power. The intermediate-pressure turbine exhaust steam enters the low-pressure turbine to generate power, and then condenses in the condenser. This condensate is sent to the low-pressure feed water heater system and deaerator by the condensate pump. The feedwater degassed by this deaerator is sent to a high-pressure feedwater heater by a booster pump and a feedwater pump to be heated, and then returned to the boiler.

Here, in the boiler, the feedwater passes through a economizer, an evaporator, and a superheater to become high-temperature and high-pressure steam. On the other hand, the boiler combustion gas that heated the steam exited the economizer,
Enter the air heater to heat the air. Here, the feedwater pump is driven by a feedwater pump drive turbine that operates with the extracted steam from the medium pressure turbine.

In the high-temperature high-pressure steam turbine plant configured as described above, the temperature of the feedwater exiting the high-pressure feedwater heater system is much higher than the feedwater temperature in the conventional thermal power plant. The temperature of the combustion gas exiting the economizer will also be much higher than in conventional boilers. Therefore, heat is recovered from the boiler exhaust gas so as not to lower the gas temperature.

A higher strength rotor shaft for a 1050 MW class generator is used. In particular, C0.1
5 to 0.30%, Si 0.1 to 0.3%, Mn 0.5% or less, Ni 3.25 to 4.5%, Cr 2.05 to 3.0%, M
o It has a fully tempered bainite structure containing 0.25 to 0.60% and V 0.05 to 0.20%, and has a room temperature tensile strength of 93 kgf.
/ Mm ² or more, especially 100 kgf / mm ² or more, 50% FATT
Is preferably 0 ° C or less, particularly preferably -20 ° C or less,
Preferably, the magnetizing force at 21.2 KG is 985 AT / cm or less, the total amount of P, S, Sn, Sb and As as impurities is 0.025% or less, and the Ni / Cr ratio is 2.0 or less. .

A central hole is provided in each of the rotor shafts of the high-, medium-, and low-pressure turbines, and through this central hole, the presence or absence of a defect is inspected by ultrasonic inspection, visual inspection, and fluorescence inspection. Further, the inspection can be performed by ultrasonic inspection from the outer surface, and the center hole may not be provided.

Table 4 shows the chemical compositions (% by weight) of the materials used for the main parts of the high-pressure turbine, medium-pressure turbine and low-pressure turbine according to the power plant of this embodiment. In this embodiment, since the high-temperature portion of the high-pressure portion and the intermediate-pressure portion are all made to have a thermal expansion coefficient of about 12 × 10 ⁻⁶ / ° C. having a ferrite crystal structure, there is no problem due to the difference in the thermal expansion coefficient. Did not.

[0082]

[Table 4]

For the rotor shafts of the high-pressure turbine and the medium-pressure turbine, 30 tons of heat-resistant steel described in Table 4 was melted in an electric furnace, carbon was deoxidized in a vacuum, cast into a mold, and forged to produce an electrode rod. Then, the electroslag was melted again as the electrode rod so as to melt from the upper part to the lower part of the cast steel, and forged into a rotor shape (diameter 1050 mm, length 3700 mm) and formed. This forging is performed at 1150 ° C to prevent forging cracks.
The test was performed at the following temperature. After annealing the forged steel, 1
It is obtained by heating to 050 ° C., performing water spray cooling, quenching, tempering twice at 570 ° C. and 690 ° C., and cutting to the final shape. In the high-pressure turbine, the upper side of the electroslag ingot was set to the first stage blade side, and the lower part was set to the last stage side. Each rotor shaft has a center hole, and the center hole can be eliminated by reducing impurities. And Al is 0.004%
And the Ni / Co ratio is 0.04. The creep rupture strengths at 10 ³ h, 10 ⁴ h and 10 ⁵ h at 650 ° C. of the central part of the rotor shaft of this embodiment are as shown in No. 1 of Table 1. It was equivalent to a few. In particular, it exhibited high strength on the long-time side.

Further, as a result of examining the center portion of the rotor shaft, it was found that the characteristics required for high-pressure, medium-pressure and high-to-medium-pressure turbine rotors (625 ° C., 10 ⁵ h strength ≧ 10 kg)
f / mm ² , 20 ° C Shock absorption energy ≧ 1.5 kgf-m)
Was sufficiently satisfied. As a result, 620
It has been demonstrated that a steam turbine rotor that can be used in steam at a temperature of 100 ° C. or more can be manufactured.

The blades and nozzles of the high-pressure part and the medium-pressure part were prepared by melting the heat-resistant steel shown in Table 4 in a vacuum arc melting furnace to form a blade and nozzle material (width 150 mm, height 50 mm, length 1000 mm). Forged and molded. The forging was performed at a temperature of 1150 ° C. or less in order to prevent forging cracks. The forged steel was heated to 1050 ° C., subjected to oil quenching, tempered at 690 ° C., and then cut into a predetermined shape.

As a result of investigating the characteristics of this blade,
It was confirmed that the characteristics (625 ° C., 10 ⁵ h strength ≧ 15 kgf / mm ² ) required for the first stage blade of the high-pressure and intermediate-pressure turbine were sufficiently satisfied. This demonstrated that a steam turbine blade usable in steam at 620 ° C. or higher can be manufactured.

The internal casing of the high pressure section and the medium pressure section, the main steam stop valve casing and the steam control valve casing are shown in Table 4.
Was melted in an electric furnace, and after ladle refining, it was cast into a sand mold to produce. By performing sufficient refining and deoxidation before casting, a casting free of casting defects such as shrinkage cavities was obtained. Weldability evaluation using this casing material
The measurement was performed according to IS Z3158. The pre-heating, inter-pass and post-heating onset temperatures were 200 ° C., and the post-heating was 400 ° C. × 30 minutes. No weld crack was observed in the material of the present invention, and the weldability was good.

Further investigation of the characteristics of this casing revealed that the characteristics required for a high-pressure, medium-pressure, high-medium-pressure turbine casing (625 ° C., 10 ⁵ h strength ≧ 10 kgf / mm ² , 20
(Impact absorption energy ≧ 1 kgf-m) was confirmed and welding was possible. This gives 6
It has been demonstrated that a steam turbine casing usable in steam at 20 ° C. or higher can be manufactured.

In the present embodiment, Cr-Mo low alloy steel was build-up welded on the journals of the high and medium pressure turbine rotor shafts to improve the bearing characteristics. As a test welding rod, a coated arc welding rod (4.0 m in diameter) shown in Table 5 (% by weight) was used.
m), overlay welding was performed for each layer shown in Table 6 by combining the welding rods used for each layer, and eight layers were welded. The thickness of each layer is 3 ~
4 mm, the total thickness was about 28 mm, and the surface was ground about 5 mm. Welding conditions were preheating, between passes, a stress relief annealing (SR) start temperature of 250 to 350 ° C, and SR processing conditions were 630 ° C for 36 hours.

[0090]

[Table 5]

[0091]

[Table 6]

[0092] In order to confirm the performance of the welded portion, the plate material was similarly overlaid and subjected to a side bending test of 160 °. However, no crack was observed in the welded portion. However, there was no adverse effect on the bearing, and the oxidation resistance was excellent.

Embodiment 3 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. In this embodiment, the tandem compound double flow type, the final stage blade length in a low pressure turbine is 46 inches, and the HP (high pressure) / IP (medium pressure) integrated type and one LP (C) or two LPs (D) have 3000 rpm. Has a rotation speed of
The high pressure section and the low pressure section are composed of the main materials shown in Table 4 described above. The steam temperature of the high pressure section (HP) is 600
℃, the pressure of 250 kgf / cm ² , the steam temperature of the intermediate pressure part (IP) is heated to 600 ℃ by a reheater,
It is operated at a pressure of 65 kgf / cm ² . The low-pressure section (LP) has a steam temperature of 400 ° C and is below 100 ° C, 722mmH
g of vacuum and sent to the condenser.

The steam turbine power plant (D) having the high-medium pressure integrated turbine and two low-pressure turbines in tandem in this embodiment has a distance between bearings of about 22.7 m, and the last stage rotor blade of the low-pressure turbine. Wing length (116
8 mm), which is 19.4 times, and the total distance between bearings per 1 MW at the rated output of the power plant of 700 MW is 32.4 mm. Further, in the steam turbine power plant (C) including the high-medium pressure integrated turbine and one low-pressure turbine in this embodiment, the distance between the bearings is about 14.
7 m, and the blade length of the last stage rotor blade of the low pressure turbine (1
168mm) and 12.6 times the rated output 1MW
21.0 mm.

[0095]

[Table 7]

FIG. 3 is a sectional view of a high-pressure / intermediate-pressure integrated steam turbine. The high-pressure steam turbine is connected to the high-pressure internal casing 18.
A high / medium pressure axle (high / medium pressure integrated rotor shaft) 33 in which the high pressure moving blades 16 are implanted is provided in the high pressure outer casing 19 outside the high pressure medium casing 19. High-temperature, high-pressure steam is obtained by the above-described boiler, passes through the main steam pipe, passes through the main steam inlet 28 through the flange and elbow 25 constituting the main steam inlet, and is guided from the nozzle box 38 to the first stage rotor blades. The steam enters from the center of the rotor shaft and flows toward the bearing.
The rotor blade has eight stages on the high pressure side on the left side of the figure and (about half of the right side in the figure)
Six stages are provided on the medium pressure side. A stationary blade is provided for each of these moving blades. The moving blade has a saddle type or a getter type, a dove-til type, a double tinon, a high pressure side first stage blade length of about 40 mm, and a medium pressure side first stage blade length of 100 mm. The length between the bearings 43 is about 6.7 m, the diameter of the smallest part corresponding to the stationary blade part is about 740 mm, and the ratio of the length to the diameter is about 9.0.

The materials having the chemical composition (% by weight) shown in Table 4 above were used for the main parts of the high-to-medium pressure turbine and the low-pressure turbine of this embodiment. The one described in Example 2 was used as the high / medium pressure integrated rotor shaft. Further, the high / medium pressure integrated rotor shaft has a center hole, but particularly, P0.01.
0% or less, S 0.005% or less, As 0.005% or less, S
The center hole can be eliminated by the high purification of n 0.005% or less and Sb 0.003% or less. Furthermore, a build-up welded layer of Cr-Mo low alloy steel on the bearing portion was formed in the same manner. As the generator shaft, a high-strength shaft is used as in the second embodiment.

In the rotor shaft on the high pressure side, the first stage and the last stage have the widest width of the blade implant root portion at the first stage, and the second stage to the seventh stage
The stage is smaller, 0.40 to 0.56 times of the first stage and the same size, and the last stage is between the first and second to seventh stages, and 0.46 of the first stage. It is ~ 0.62 times the size.

The length of the blade portion of the moving blade on the high pressure side is 35 to 50 mm in the first stage and becomes longer in each stage from the second stage to the last stage, and particularly from the second stage to the last stage depending on the output of the steam turbine. Is in the range of 50 to 150 mm, the number of stages is in the range of 7 to 12 stages, and the length of the wing portion of each stage is 1.05 to 1.05 in which the downstream side is adjacent to the upstream side.
The length is increased within the range of 1.35 times, and the ratio gradually increases on the downstream side.

The medium-pressure steam turbine rotates the generator discharged from the steam discharged from the high-pressure steam turbine together with the high-pressure steam turbine by the steam heated again to 600 ° C. by the reheater, and is rotated at 3000 rpm. You. The intermediate pressure side turbine has an intermediate pressure inner second casing 21 and an intermediate pressure outer casing 22 similarly to the high pressure side turbine, and a stationary blade is provided to oppose the intermediate pressure moving blade 17. Medium pressure blade 17 is 6
It is a step. The first stage blade length is about 130mm, and the last stage blade length is about 26
0 mm. Dovetil is an inverted chestnut type.

The rotor shaft on the medium pressure side has the largest axial width at the root portion of the blade implanted root portion at the first stage, the second stage is smaller than the first stage, and the third to fifth stages are smaller than the second stage.
The width of the last stage is between the third and fifth stages and the second stage, and is 0.48 to 0.64 times the width of the first stage. The first stage is 1.1 to 1.
5 times.

The length of the blade portion of the moving blade on the medium pressure side becomes longer in each stage from the first stage to the last stage. Depending on the output of the steam turbine, the length from the first stage to the last stage becomes 90%.
３５０350 mm, the number of stages is in the range of 6 to 9 stages, and the length of the wing of each stage is 1.
It is longer at a rate of 10 to 1.25.

The implanted portion of the moving blade has a larger diameter than that corresponding to the stationary blade, and its width is related to the blade length and position of the moving blade. The ratio of the width to the blade length of the rotor blade is the largest in the first stage, 1.35 to 1.80 times, the second stage is 0.88 to 1.18 times, and the third to sixth stages are the final stages. It is smaller and is 0.40 to 0.65 times.

The high-to-medium pressure integrated turbine for a steam turbine power plant equipped with two low-pressure turbines connected to a tandem according to the present embodiment has a bearing distance of about 6.7 m, and the blade of the last stage blade of the low-pressure turbine. It is 5.7 times the unit length (1168 mm) and 9.57 m per 1 MW of rated output
m.

Also in the present embodiment, a low-alloy steel overlay welding layer is provided on the bearing portion of the high / medium pressure integrated steam turbine rotor shaft as in the second embodiment.

FIG. 4 is a sectional view of the low-pressure turbine. There are one low pressure turbine or two in tandem, both of which are tandemly coupled to high and medium pressure turbines. The moving blades 41 have six stages on the left and right sides and are substantially symmetrical on the left and right, and stationary blades 42 are provided corresponding to the moving blades. The last stage rotor blade has a length of 4
6 inches, and a Ti-based alloy or a high-strength 12% Cr steel is used as in the second embodiment. As for the rotor shaft 44, a forged steel having a fully tempered bainite structure of a super-clean material is used as in the second embodiment. A 12% Cr steel containing 0.1% Mo is used for each of the moving blades and stationary blades other than the last stage and the preceding stage. C for inner and outer casing material
0.25% of cast steel of the above composition is used. The center-to-center distance of the bearing 43 in this embodiment is 8 m, the diameter of the rotor shaft corresponding to the stationary blade portion is about 800 mm, and the diameter of the rotor blade implant portion is the same at each stage. The distance between the bearing centers with respect to the rotor shaft diameter corresponding to the stationary blade portion is ten times.

[0107] The 46-inch wing of this embodiment has C0.23
%, Si 0.06%, Mn 0.15%, Cr 11.4
%, Ni 2.65%, Mo 3.10%, V 0.25%,
Quenching and tempering were performed using a martensitic steel containing 0.11% of Nb and 0.06% of N. This product has a tensile strength of 145 kg / mm ² and a V notch impact value of 6.2 kg.
m / cm ² .

The rotor shaft is provided with a rotor blade implanted portion. For the last dovetail, an inverted Christmas tree type is used in addition to a fork type.

In the low-pressure turbine, the axial width of the root portion of the blade implantation is the smallest at the first stage, and the two stages are equal at the downstream side, the four stages and the fifth stage are equal, and gradually increased at the four stages. The width of the last stage is 6.2 to 7.0 times larger than the width of the first stage. A few steps are 1.15 to 1.40 times the first step,
4,5 stage is 2.2-2.6 times of 2-3 stage, last stage is 4,5
It is 2.8 to 3.2 times the stage. The width of the root portion is indicated by a point connecting the extended line extending to the diameter of the rotor shaft.

In this embodiment, the blade length of the moving blade is longer at each stage from the initial stage of 4 ″ to the final stage of 46 ″, up to 8 stages, and the blade length of each stage is downstream. The length adjacent to the upstream side is gradually increased within a range of 1.2 to 1.9 times.

The implanted root portion of the moving blade has a large diameter and widens as compared with the portion corresponding to the stationary blade, and its width increases as the blade length of the moving blade increases. The ratio of the width to the blade length of the rotor blade is from 0.30 to 1.5 from the first stage to the last stage, and the ratio gradually decreases from the first stage to the last stage before the last stage. Is 0.15 or higher than the previous one.
It gradually decreases within the range of 0.40. The last stage has a ratio of 0.50 to 0.65.

The average diameter of the last stage rotor blade in this embodiment is 3000 rpm, 2590 mm with a 43 ″ blade, 360 mm
0rpm, 36 "wings 2160mm, 3000rpm, 46"
2665mm with wings, 3600rpm, 2220mm with 38 "wings
And

The erosion shield according to the present embodiment is similar to the erosion shield described above in that the stellite alloy plate is formed by electron beam welding or T-beam welding.
Joined by IG welding. The erosion shield is welded over the entire length of the erosion shield member at two places, the front side and the back side where the wet steam is directly applied. The front side is wider than the back side, and the upper and lower ends are also welded.

The high-temperature high-pressure steam turbine power plant in this embodiment is mainly composed of a boiler, high-medium-pressure turbine, low-pressure turbine, condenser, condensate pump, low-pressure feedwater heater system, deaerator, booster pump, feedwater pump, high-pressure feedwater. It is composed of a heater system. That is, the ultra-high-temperature and high-pressure steam generated in the boiler enters the high-pressure side turbine and generates power, and is then reheated in the boiler again to enter the medium-pressure side turbine and generate power. The high- and medium-pressure turbine exhaust steam enters the low-pressure turbine and generates power, and then condenses in the condenser.
This condensate is sent to the low pressure feed water heater system and deaerator by the condensate pump. The feedwater degassed by this deaerator is sent to a high-pressure feedwater heater by a booster pump and a feedwater pump to be heated, and then returned to the boiler.

Here, the water supply in the boiler passes through a economizer, an evaporator, and a superheater to become high-temperature and high-pressure steam. On the other hand, the boiler combustion gas that heated the steam exited the economizer,
Enter the air heater to heat the air. Here, the feedwater pump is driven by a feedwater pump drive turbine that operates with the extracted steam from the medium pressure turbine.

In the high-temperature high-pressure steam turbine plant configured as described above, the temperature of the feedwater exiting the high-pressure feedwater heater system is much higher than the feedwater temperature in the conventional thermal power plant. The temperature of the combustion gas exiting the economizer will also be much higher than in conventional boilers. Therefore, heat is recovered from the boiler exhaust gas so as not to lower the gas temperature.

In addition to the present embodiment, the steam inlet temperature of the high- and medium-pressure steam turbine is 610 ° C. or higher, the steam inlet temperature to the low-pressure steam turbine is about 400 ° C., and the outlet temperature is 1000 ° C.
The same configuration can be applied to a MW class large-capacity power plant. In addition, 593 ° C or 63
Even at 0 ° C., the material constitution and structure of this embodiment can be used as they are.

[0118]

According to the present invention, a rotor shaft for a steam turbine having excellent strength at a high temperature and a long time at a specific temperature of 600 ° C. or more and 50,000 hours or more and a long time is obtained. By using a high-pressure, high-medium-pressure steam turbine, especially when applied to an ultra-supercritical steam turbine,
The steam temperature of the steam turbine can be increased to 650 ° C. or higher, and a remarkable effect can be obtained in improving the thermal efficiency of the steam turbine power plant.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view in which a high-pressure steam turbine and a medium-pressure steam turbine are connected.

FIG. 2 is a sectional view of a low-pressure steam turbine.

FIG. 3 is a cross-sectional view of a high- and medium-pressure steam turbine.

FIG. 4 is a sectional view of a low-pressure steam turbine.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... 1st bearing, 2 ... 2nd bearing, 3 ... 3rd bearing, 4 ... 4th
Bearing, 5: Thrust bearing, 10: First shaft packing, 1
DESCRIPTION OF SYMBOLS 1 ... 2nd shaft packing, 12 ... 3rd shaft packing, 13 ... 4th shaft packing, 14 ... High-pressure diaphragm, 1
5: Medium pressure diaphragm, 16: High pressure blade, 17: Medium pressure blade, 18
... High-pressure internal casing, 19 ... High-pressure external casing, 20 ... Medium-pressure internal first casing, 21 ... Medium-pressure internal second casing, 22 ... Medium-pressure external casing, 23 ... High-pressure axle, 24 ... Medium pressure Axle, 25 ... flange, elbow, 26 ... front bearing box, 28 ... main steam inlet, 2
9: Reheat steam inlet, 30: High pressure steam exhaust port, 31: Cylinder connecting pipe, 33: High and medium pressure axle, 38: Nozzle box (high pressure first stage), 39: Thrust bearing wear cutoff device, 40: Warm-up steam Inlet, 41: moving blade, 42: stationary blade, 43: bearing, 44
... rotor shaft.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroyuki Doi 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Inside the Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Kenichiro Nomura 3-1-1 Sachimachi, Hitachi City, Ibaraki Prefecture No. 1 Inside the Thermal and Hydro Power Division, Hitachi, Ltd. (72) Inventor Ryo Hiraga 4-6 Kanda Surugadai, Chiyoda-ku, Tokyo Inside Hitachi, Ltd. (72) Inventor Toshio Fujita 1-1-14 Mukooka, Bunkyo-ku, Tokyo No. 4 F term (reference) 3G002 AA07 AA11 AB00

Claims (14)

[Claims] (1) 0.05 to 0.20% by weight of C, 0.2% by weight of Si
2% or less, Mn 0.01 to 1.5%, Ni 0.01 to
1.0%, Cr 9.0-13.0%, Mo 0.05-0.5
%, W 0.5 to 5.0%, V 0.05 to 0.30%, Nb
0.01 to 0.20%, Co 1.0 to 2.0%, N 0.0
1 to 0.1%, B 0.001 to 0.030% and Al0.0
005 to 0.006%, and the (Ni / Co) ratio is 0.000%.
A rotor shaft for a steam turbine, wherein the rotor shaft is made of martensite steel of 15 or less. 2. 0.05 to 0.20% of C, 0.2% of Si by weight.
2% or less, Mn 0.01 to 1.5%, Ni 0.2% or less,
Cr 9.0-13.0%, Mo 0.05-0.5%, W0.5.
5 to 5.0%, V 0.05 to 0.30%, Nb 0.01 to
0.20%, Co 0.5-10.0%, N 0.01-0.1%
1%, 0.001 to 0.030% of B and 0.0005 of Al
A rotor shaft for a steam turbine, comprising -0.006% and having a (Ni / Co) ratio of 0.15 or less. 3. The composition according to claim 1, wherein the content of C is 0.05 to 0.20% and the content of Si is 0.2.
2% or less, Mn 0.01 to 1.5%, Ni 0.01 to
1.0%, Cr 9.0-13.0%, Mo 0.05-0.5
%, W 0.5 to 5.0%, V 0.05 to 0.30%, Nb
0.01 to 0.20%, Co 0.5 to 10.0%, N 0.01 to
0.1%, B 0.001-0.030% and Al 0.000
5 to 0.006%, and the (Ni / Co) ratio is 0.09
A steam turbine rotor shaft comprising the following martensitic steel. 4. The composition according to claim 1, wherein the content of C is 0.05 to 0.20% and the content of Si is 0.2%.
2% or less, Mn 0.01 to 1.5%, Ni 0.2% or less, Cr 9.0 to 13.0%, Mo 0.05 to 0.5%, W
0.5 to 5.0%, V 0.05 to 0.30%, Nb 0.01
~ 0.20%, Co 1.0 ~ 2.0%, N 0.01 ~ 0.1%.
1%, 0.001 to 0.030% of B and 0.0005 of Al
A rotor shaft for a steam turbine, comprising -0.006% and a (Ni / Co) ratio of 0.2 or less. 5. The composition according to claim 5, wherein C is 0.05 to 0.20% by weight and Si is 0.2%.
2% or less, Mn 0.01 to 1.5%, Ni 0.01 to
1.0%, Cr 9.0-13.0%, Mo 0.05-0.5
%, W 0.5 to 5.0%, V 0.05 to 0.30%, Nb
0.01 to 0.20%, Co 0.5 to 10.0%, N 0.01 to
Made of martensitic steel containing 0.1% and B0.001~0.030%, 650 ℃, steam turbine rotor shaft, characterized in that 10 ⁵ hours creep rupture strength of 10.5 kg / mm ² or more . 6. A rotor shaft, and a first stage is implanted in a double-flow structure at a center portion of the rotor shaft, and at least one side has a five-stage structure.
In a high-pressure steam turbine having a rotor blade implanted in stages or more, a stator blade for guiding the flow of steam to the rotor blade, and an inner casing for holding the stator blade, the rotor shaft may be configured as described in claims 1 to 5. A high-pressure steam turbine comprising the steam turbine rotor shaft according to any one of the above. 7. A rotor shaft, a rotor blade having a first stage implanted in the center of the rotor shaft in a double-flow structure, and six or more stages symmetrically implanted in each of the left and right directions, and guiding inflow of steam to the rotor blade. 6. A medium-pressure steam turbine comprising: a stationary blade having a stationary blade; and an inner casing for holding the stationary blade, wherein the rotor shaft comprises the rotor shaft for a steam turbine according to any one of claims 1 to 5. Steam turbine. 8. The rotor shaft, comprising: a rotor shaft; a moving blade implanted on the rotor shaft; a stationary blade for guiding the flow of steam into the rotating blade; and an inner casing for holding the stationary blade. A high-pressure turbine section into which high-temperature and high-pressure steam flows from a central portion of six or more stages of rotor blades implanted in the turbine; and heating the steam discharged from the high-pressure turbine section and implanting the steam into the rotor shaft. A high-to-medium-pressure steam turbine having a medium-pressure side turbine portion into which high-temperature and medium-pressure steam flows from a central portion of five or more stages of blades, wherein the rotor shaft is a rotor for a steam turbine according to any one of claims 1 to 5. A high-to-medium pressure steam turbine comprising a shaft. 9. A rotor shaft, and a first stage is implanted in a double-flow structure at a central portion of the rotor shaft, and at least one side has a five-stage structure.
In a high-pressure steam turbine having a rotor blade implanted in stages or more, a stator blade for guiding the flow of steam to the rotor blade, and an inner casing holding the stator blade, the rotor shaft has a weight of C0. 0.5 to 0.20%, Si 0.2% or less,
Mn 0.01-1.5%, Ni 0.005-0.15
%, Cr 9.0 to 13.0%, Mo 0.05 to 0.5%, W
0.5 to 5.0%, V 0.05 to 0.30%, Nb 0.01
~ 0.20%, Co 1.0 ~ 2.0%, N 0.01 ~ 0.1%.
1%, 0.001 to 0.030% of B and 0.0005 of Al
A high-pressure steam turbine comprising martensitic steel containing up to 0.006%. 10. A rotor shaft, a rotor blade in which a first stage is implanted in a central portion of the rotor shaft in a double flow structure, and six or more stages are symmetrically implanted in each of the left and right directions, and guides inflow of steam to the rotor blade. In a medium-pressure steam turbine having a stationary vane and an inner casing for holding the stationary vane, the rotor shaft has a weight of C 0.05 to 0.20%, Si 0.2% or less, Mn
0.01-1.5%, Ni 0.005-0.15%, C
r 9.0 to 13.0%, Mo 0.05 to 0.5%, W 0.5
-5.0%, V 0.05-0.30%, Nb 0.01-0.0%.
20%, Co 1.0 to 2.0%, N 0.01 to 0.1%,
B 0.001-0.030% and Al 0.0005-0.5.
A medium-pressure steam turbine comprising martensitic steel containing 006%. 11. A rotor shaft comprising: a rotor shaft; a moving blade implanted on the rotor shaft; a stationary blade for guiding the flow of steam into the rotating blade; and an inner casing for holding the stationary blade. A high-pressure turbine section into which high-temperature and high-pressure steam flows from a central portion of six or more stages of rotor blades implanted in the turbine; and heating the steam discharged from the high-pressure turbine section and implanting the steam into the rotor shaft. In a high-to-medium-pressure steam turbine having a high-pressure / medium-pressure turbine portion into which high-temperature and medium-pressure steam flows from a central portion of five or more stages of rotor blades, the rotor shaft has a weight of 0.05 to 0.20%, and 0.2 of Si. % Or less, Mn0.
01-1.5%, Ni 0.005-0.15%, Cr
9.0-13.0%, Mo 0.05-0.5%, W0.5-
5.0%, V 0.05 to 0.30%, Nb 0.01 to 0.2
0%, Co 1.0 to 2.0%, N 0.01 to 0.1%, B
0.001-0.030% and Al 0.0005-0.0
A high- and medium-pressure steam turbine comprising a martensitic steel containing 0.6%. 12. A steam turbine power plant in which a high-pressure turbine, a low-pressure turbine, and a generator are connected in tandem, and a medium-pressure turbine, a low-pressure turbine, and a generator are connected in tandem. The high pressure steam turbine and the intermediate pressure turbine according to claim 9 are claim 7.
Or a steam turbine power plant comprising at least one of the medium-pressure steam turbines described in 10 above. 13. A steam turbine power plant in which a high-pressure turbine, an intermediate-pressure turbine, and a generator are connected in tandem, and a low-pressure turbine, a low-pressure turbine, and a generator are connected in tandem. The high pressure steam turbine and the intermediate pressure turbine according to claim 9 are claim 7.
Or a steam turbine power plant comprising at least one of the medium-pressure steam turbines described in 10 above. 14. A steam turbine power plant in which a high-to-medium pressure turbine, a low-pressure turbine, and a generator are connected in tandem, wherein the high-to-medium pressure turbine comprises the high-to-medium pressure steam turbine according to claim 8 or 11. Steam turbine power plant.