JP2000282808A - Steam turbine equipment - Google Patents

Abstract

(57) [Summary] In a steam turbine power generation facility having a steam turbine with a steam condition of 650 ° C. or higher, a Ni-based alloy, C
An object of the present invention is to provide a steam turbine facility capable of overcoming manufacturing difficulties caused by the use of an austenitic material represented by an o-base alloy. SOLUTION: A turbine casing of a steam turbine is formed by:
A Ni-based alloy comprising a plurality of split casings divided in the turbine axial direction and integrally connected, wherein at least one of the split casings exposed to a temperature of 650 ° C. or more includes a Ni-based alloy containing 35% or more of Ni. Alternatively, it was formed of an austenitic steel material represented by a Co-based alloy containing 50% or more of Co.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for producing a slag having a steam condition of 650.
The present invention relates to a steam turbine power generation facility having a steam turbine of at least ℃.

[0002]

2. Description of the Related Art High temperature and high pressure steam conditions in a thermal power plant are very important and fundamental factors contributing to the improvement of efficiency, but in the late 1960s, 24.1 MPa,
Since the 538/566 ° C single-stage reheat steam condition was established as a standard for Japanese commercial thermal turbines, no breakthrough has been made until recently. However, since the oil crisis, energy saving has been strongly promoted, and rapid interest in the issue of global warming has increased the efficiency of thermal power plants.

The most effective means for increasing the power generation efficiency is to raise the steam temperature of a steam turbine. However, since the steam conditions of the conventional steam turbine equipment are steam temperatures of 600 ° C. class or less, the steam turbine Ferrite heat-resistant steel is used for main members such as rotors and blades. That is, as a conventional high-efficiency turbine material, for example, high-strength heat-resistant steel as disclosed in Japanese Patent Publication No. 60-31898, Japanese Patent Publication No. 60-54385, or Japanese Patent Application Laid-Open No. 2-149649 is known. In particular, heat-resistant steels having higher high-temperature strength as these materials are disclosed in
High-strength heat-resistant steels such as those disclosed in JP-A-3697 and JP-A-7-34202 are known.

[0004]

When the steam conditions of the steam turbine facility reach a steam temperature of 650 ° C. or higher, ferrite-based materials are used for the main members such as nozzles, blades, and rotors of the steam turbine. In such a case, a Ni-based alloy, an austenitic material, or the like is used because the strength becomes severe.

However, these Ni-based alloys and austenitic materials have a problem that the production of large ingots is limited. Therefore, it has been extremely difficult to apply Ni-based alloys and austenitic materials to steam valves and turbine casings of large commercial steam turbines. Further, even if it is applied, there is a problem that the reliability is low because the material properties cannot be said to be good due to the large steel ingot.

[0006] In view of the above, the present invention relates to a steam turbine power generation facility having a steam turbine having a steam condition of 650 ° C. class or more, which is manufactured by using an austenitic material represented by a Ni-based alloy or a Co-based alloy. It is an object of the present invention to obtain a steam turbine power generation facility capable of overcoming the above difficulties.

[0007]

According to a first aspect of the present invention, in a steam turbine facility having a steam turbine into which steam having a steam temperature of 650 ° C. or more is introduced, a turbine casing of the steam turbine is divided in a turbine axial direction. It is constituted by connecting a plurality of divided casings integrally,
At least one of the divided casings exposed to a temperature of 650 ° C. or more was formed of an austenitic steel material represented by a Ni-based alloy containing 35% or more of Ni or a Co-based alloy containing 50% or more of Co. It is characterized by the following.

A second invention is characterized in that, in the first invention, a split casing other than the split casing formed of an austenitic steel material is formed of a ferritic steel material represented by 12Cr steel. And

Further, in the third invention, the steam temperature is 650.
In a steam turbine facility having a steam turbine into which steam at a temperature of at least 0 ° C. is introduced, a rotor of the steam turbine is configured by integrally connecting a plurality of split rotors split in an axial direction, and 650 of the split rotors are provided. At least one split rotor exposed to a temperature of at least
It is formed of an austenitic steel material represented by a Ni-based alloy containing 5% or more.

In a fourth aspect of the present invention, the split rotor other than the split rotor formed of the austenitic steel material is Cr.
It is characterized by being formed of a ferritic steel material represented by MoV forged steel.

In the fifth invention, the steam temperature is 650 ° C.
In a steam turbine facility having a steam turbine in which the above steam is introduced, a main steam stop valve, a steam control valve, or a steam valve casing of a reheat valve is formed by integrally connecting a plurality of divided parts, 50% of a Ni-based alloy or Co containing 35% or more of Ni in a main divided portion exposed to a temperature of 650 ° C. or more among the divided portions.
It is characterized by being formed of an austenitic steel material represented by a Co-based alloy as described above.

According to a sixth aspect, in the second aspect, the divided casings are connected to each other by bolting, and an overlapping portion radially overlapping the dissimilar material joining portion between the austenitic steel material and the ferritic steel material is provided. The overlapping portion of the split casing made of austenitic steel material is arranged on the radial inner side, the overlapping portion of the split casing made of ferritic steel material is arranged on the radial outer side, and the gap between the overlapping portions is set at room temperature. It is characterized in that it is set to zero or a minute value in the state.

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a diagram showing one system configuration of the steam turbine power generation equipment according to the present invention, which includes an ultra high pressure turbine 1, a high pressure turbine 2, a medium pressure turbine 3, a first low pressure turbine 4, and a second low pressure turbine. 5 and a generator 6 are connected in a single shaft, and the ultrahigh-pressure turbine 1 and the high-pressure turbine 2 are incorporated in the same outer casing to be independent.

Thus, the 6 generated by the boiler heater 7
High-temperature and high-pressure steam of 50 ° C. or more is introduced into the ultra-high pressure turbine 1, where the work is performed, and
C. or higher, and the reheated steam is introduced into the high-pressure turbine 2. The steam introduced into the high-pressure turbine 2 and performing work is heated again by the second-stage reheater 9 to become a steam having a predetermined temperature of 650 ° C. or less, and the intermediate-pressure turbine 3, the first and the second
Are sequentially introduced into the low-pressure turbines 4 and 5 to perform work and drive the generator 6.

FIG. 2 is a diagram showing another system configuration of the steam turbine power generation equipment, in which a first ultra-high-pressure high-temperature turbine 10a, a second ultra-high-pressure high-temperature turbine 10b, an ultra-high-pressure turbine 1, a high-pressure turbine 2, and The pressure turbine 3, the first low-pressure turbine 4, the second low-pressure turbine 5, and the generator 6 are connected to one shaft. First ultra-high pressure high temperature turbine 1
0a constitutes a part of the ultrahigh-pressure turbine 1, the second ultra-high-pressure high-temperature turbine 10b constitutes a part of the high-pressure turbine 2, and the first and second ultra-high-pressure high-temperature turbines It is built in the same outer casing and is constituted as an independent thing.

Thus, the 6 generated by the boiler heater 7
After the high-temperature high-pressure steam of 50 ° C. or more is introduced into the first ultra-high-pressure high-temperature turbine 10a and performs work, the ultra-high-pressure turbine 1
Will be introduced. The steam introduced into the ultra high pressure turbine 1 and performing work is reheated to 650 ° C. or higher in the first stage reheater 8, and the reheated steam is introduced into the second ultra high pressure high temperature turbine 10b. The steam that has worked in the second ultra-high-pressure high-temperature turbine 10b is introduced into the high-pressure turbine 2, where the steam that has worked is reheated in the second-stage reheater 9 and 650
When the temperature reaches a predetermined temperature of not more than 0 ° C., it is sequentially introduced into the intermediate-pressure turbine 3 and the first and second low-pressure turbines 4 and 5 to perform work and drive the generator 6.

FIG. 3 is a vertical sectional view of the upper half casing of the turbine in which the ultrahigh-pressure turbine 1 and the high-pressure turbine 2 shown in FIG. 1 are provided. It is arranged in. Inside the outer casing 11, an inner casing 12 is provided.
The turbine rotor 13 is inserted into the inner casing 12, and the ultrahigh-pressure turbine 1 is formed by a nozzle, a rotor blade, and the like provided in one half (the left half in the figure) of the inner casing 12. The high-pressure turbine 2 is configured by a nozzle, a moving blade, and the like provided in the other half (the right half in the figure) of the inner casing 12.

Thus, 65 generated by the boiler heater was used.
High-temperature and high-pressure steam of 0 ° C. or higher passes through the main steam pipe 14 and is introduced into the ultrahigh-pressure turbine 1 through the first nozzle 15 and flows leftward in the drawing to perform work. On the other hand, the first high-temperature reheat tube 1
The steam reheated to a temperature of 650 ° C. or more by 6 is introduced into the high-pressure turbine 2 and flows to the right in the figure to perform work.

The inner casing 12 is, for example, divided into three divided casings 12a and 12a in the axial direction of the turbine.
b, 12c, and the divided casing 12
a, 12b and 12c are integrally connected to each other. And at least one of the divided casings 12b which is exposed to high-temperature steam of
However, a Ni-based alloy containing 35% or more of Ni or 50% of Co
% Of an austenitic steel material typified by a Co-based alloy containing at least
a and 12c are formed of a ferritic steel material represented by 12Cr steel.

Similarly, the turbine rotor 13 is also axially divided into, for example, three divided rotors 13a, 13b, 13c, and the divided rotors 13a, 13b, 13c are integrally connected. In particular, among the split rotors, 65
At least one split rotor 13b exposed to high-temperature steam of 0 ° C. or more is formed of an austenitic steel material represented by a Ni-based alloy containing 35% or more of Ni, and the other divided rotors 13a and 13c are represented by CrMoV forged steel. It is formed of a ferritic steel material.

As described above, since the inner casing or the turbine rotor is manufactured by being divided into a plurality of parts, an austenitic steel material such as a Ni-based alloy which is high in temperature and high in strength but difficult to manufacture a large ingot is difficult. It is also possible to manufacture a split casing or split rotor by dividing it into small ingots, and to put the casing or turbine rotor into practical use with an austenitic steel material such as a Ni-based alloy having excellent high-temperature strength. Can be. Therefore, it is possible to obtain safe, highly reliable and low-cost steam turbine equipment having a steam temperature of 650 ° C. or higher. In particular, when a Co-based alloy containing 50% or more of Co, which is superior to Ni-based alloys in producing large ingots among austenitic materials, is applied to at least one divided casing 12b of the divided casing, It is easy to manufacture, and it is possible to manufacture a homogeneous and good-quality material, and it is possible to easily achieve the manufacturing while sufficiently securing the strength of a turbine casing that is a large stationary part.

On the other hand, the cost can be reduced by applying a ferritic steel material to the split casing 12a, 12c or the split rotors 13a, 13c other than the split casing 12b or the split rotor 13b formed of the austenitic steel material. Can be realized.

In the above embodiment, the split casings 12a and 12c are made of a ferrite-based steel material represented by 12Cr steel. However, the ferrite-based steel materials include CrMo steel and CrM steel.
An oV steel may be used, and the presence or absence of a trace amount additive such as B does not matter. NiCrMoV steel or 12Cr steel other than CrMoV steel may be applied to the split rotors 13a and 13c, regardless of the presence or absence of trace additives such as Nb and B.

FIG. 4 is a vertical sectional view of the upper half casing of the turbine in which the first and second ultra-high pressure high-temperature turbines 10a and 10b in FIG. 2 are provided. 10 a and 10 b are disposed in the same outer casing 17. An inner casing 18 is provided in the outer casing 17, and an ultra-high-pressure high-temperature turbine 10a is configured by a nozzle, a moving blade, and the like provided in one half (the left half in the figure) of the inner casing 18, The ultra-high-pressure high-temperature turbine 10b is constituted by nozzles, rotor blades, and the like provided in the other half (the right half in the figure) of the inner casing 18.

In this case as well, the inner casing 18 is, for example, divided into three divided casings 18a,
18b, 18c, and the divided casings 18a, 18b, 18c are integrally connected to each other. Then, the divided casings 18a, 18b, 18
a, austenitic steel material represented by a Ni-based alloy containing 35% or more of Ni or a Co-based alloy containing 50% or more of Co. The other split casings 18a and 18c are made of 12Cr
It is formed of a ferritic steel material represented by steel.

Similarly, the turbine rotor 19 is also axially divided into, for example, three divided rotors 19a, 19b and 19c, and the divided rotors 19a, 19b and 19c are integrally connected. And among the divided rotors, in particular, 6
At least one split rotor 19b exposed to high-temperature steam of 50 ° C. or more is formed of an austenitic steel material typified by a Ni-based alloy containing 35% or more of Ni, and the other split rotors 19a and ferrite typified by 19cCrMoV forged steel It is formed of a series steel material.

The device shown in FIG. 4 has the same effect as that shown in FIG.

FIG. 5 is an explanatory view of the manufacture of the inner casing shown in FIG. 3. The split casing 12b using a Ni-based alloy containing 35% or more of Ni is made of a Ni-based alloy material in a ring shape or a semi-ring shape. Manufactured by forging.

Therefore, in this case, the amount of the ingot can be reduced to a small amount as compared with the case of manufacturing a casing having the same outer diameter with a cylindrical or block-shaped forged material, and a relatively wide material can be manufactured at once. And cost reduction can be achieved. In addition, since a forged material having uniform properties in the thickness direction can be obtained, a material having good properties can be manufactured.

The divided casings 12a, 12a,
12b, 12c or 18a, 18b, 18c and split rotors 13a, 13b, 13c or 19a, 19b,
As the connecting means 19c, as shown in FIGS. 6 and 7, a connecting method using welding 20 or 21 can be applied. In this case, the rigidity of the vertical joint of each divided part is high,
It can be a continuous integral casing or rotor, and can be formed compactly without the need for disposing extra parts at the joint part, and particularly in the case of a casing, because it eliminates steam leakage from the joint part. It has high strength reliability and can sufficiently maintain the function as a pressure vessel.

The split casings 12a, 12a
b, 12c (18a, 18b, 18c) and split rotor 1
For the connection of 3a, 13b, 13c (19a, 19b, 19c), a connection method by bolting as shown in FIG. 8 or 9 can be used. That is, the flange portions 22a and 22a are connected to the connecting portions of the split rotors 13a and 13b, respectively.
22b is formed, and the flange portions are connected by bolts 23. Similarly, in the case of a rotor, the split rotor 13
a and 13b are connected to the flanges 24a and 24b, respectively.
b is formed, and its flange portion is connected by a bolt 25.

In this case, the difference in the amount of deformation caused by the difference in the amount of thermal expansion generated between the materials having different coefficients of linear expansion can be released by the slip of the joint surface, and excessive heat is applied to the joint. The generation of stress can be prevented. Moreover, when the turbine casing or the turbine rotor is updated for the purpose of improving the performance of the turbine or recovering from aging after the operation of the turbine equipment, it is possible to update only the necessary divided portions of the turbine casing or the turbine rotor. Yes, maintainability can be improved. Further, when the connection of the split rotors is performed by bolting, the flange portions 24a,
It is more preferable that a radial connection portion is provided on the facing surface of 24b and the connection portions are engaged with each other.

FIG. 10 shows split casings 12a and 12b.
FIG. 9 is a view showing another embodiment of the present invention in which the bolts 23 are used to connect to the split casing 12b formed of an austenitic steel material. An annular projecting portion 26 that overlaps with the inner surface of the casing 12a is provided.

That is, in the radially overlapping portion of the divided casings, a divided casing 12b made of an austenitic steel material is arranged on the radially inner side, and the divided casing made of ferritic steel material on the radially outer side. 12a is provided. The gap a of the overlapping portion is set to zero or a minute value of 0.24% or less of the radius of the overlapping portion at room temperature.

When the temperature of the turbine casing increases during the operation of the turbine and the split casing expands in accordance with the linear expansion coefficient of each material, the austenitic steel disposed on the inner diameter side of the overlap of the casing joints. Since the thermal expansion of the split casing made of the material is larger than the thermal expansion of the split casing made of the ferritic steel material disposed on the outer diameter side, the gap between the overlapping portions is set to zero at room temperature. In this case, the temperature and the temperature increase, and the high-temperature and high-pressure steam inside the casing is prevented from leaking out of the casing.

Therefore, it is not necessary to ensure the prevention of steam leakage only by the vertical joint contact surface due to the bolt fastening force, and the joint having a thick structure can be made compact.
Thermal stress can also be reduced.

If the gap of the overlapped portion is set to a very small value at room temperature as described above, the annular protrusion of the overlapped portion is set while the steam pressure in the steam turbine has not yet sufficiently increased. Part 26 is divided casing 1
When the temperature comes into contact with the inner surface of the casing 2a and the temperature further increases, the annular projection 26 comes into firm contact with the inner surface of the split casing 12a to prevent the steam inside the casing from leaking out of the casing. Therefore, when the internal steam of the turbine is relatively low temperature and the pressure is relatively low, such as when starting the turbine, the prevention of steam leakage is secured only at the joint contact surface by bolt fastening force, and when the internal steam of the turbine becomes low temperature and high pressure. Leakage of steam from the inside of the casing due to contact of the overlapping portions formed by the annular projections 26 is reliably prevented.

Ni used for steam turbine casing
Austenitic steel material represented by base alloy and 12C
The difference in the average coefficient of linear expansion between ferrite-based materials represented by r-steel is about 5 × 10 ⁻⁶ / ° C., while the high-temperature portion of the steam turbine casing has a temperature of 500 ° C. or more during no-load operation. . Until this no-load operation, the steam pressure inside the casing is extremely low, and even if the bolt fastening force of the joint of the divided casing is small, there is no danger of steam leaking from the joint contact surface.

Therefore, if the overlapping portions of the split casings come into contact with each other by this point, the temperature further increases in the subsequent load operation, and the overlapping portions come into firm contact with each other. Therefore, it is not necessary to make the joint portion of the split casing thick and have high rigidity.

In the overlapping portion of the divided casing,
Assuming that the radius of the overlapped portion is R, the temperature T of the austenitic steel material whose average linear expansion coefficient difference Δα is about 5 × 10 ⁻⁶ / ° C. and the ferritic steel material represented by 12Cr steel is 500 ° C. The difference ΔR in the amount of thermal expansion when
When o is normal temperature, ΔR = R × Δα × (T−To), and the radius ratio ΔR / R is ΔR / R = Δα × (T−To) = 5 × 10 ⁻⁶ × (500
−25) = approximately 0.0024. Therefore, if the gap at the normal temperature of the overlapping portion of the divided casings is 0.24% or less of the radius of the overlapping portion, the overlapping portion contacts during the no-load operation. Started to do
In the subsequent load operation, the temperature further rises and the overlapped portion comes into firm contact, so that a sufficient effect of preventing steam leakage can be obtained.

FIG. 11 is a view showing another embodiment of the present invention. The valve casing 28 of the main steam stop valve 27 has a plurality of (three in the figure) split casings 28a, 28a.
b, 28c, which are integrally connected by, for example, welding. These split casings 2
8a, 28b, and 28c, at least one main split casing exposed to a high temperature of 650 ° C. or more, for example, 2
8a and 28b are Ni-based alloys containing 35% or more of Ni in the material or Co, which is superior in productivity of large ingots as compared with Ni-based alloys.
Co-based alloy containing 50% or more is applied.

However, in this valve casing,
Even in the case of Ni-based alloys that are high-strength at high temperatures but difficult to produce large ingots, it is possible to divide the ingots into smaller ingots to produce the raw material and use it to form the valve casing N that contains 35% or more of Ni, which is excellent in high-temperature strength
A valve casing using an i-base alloy can be put to practical use. Also, when a Co-based alloy containing 50% or more of Co is applied, the Co-based alloy is more excellent in productivity of a large steel ingot than the Ni-based alloy as described above. It is easier to manufacture and a uniform and good material can be manufactured, and the strength of the valve casing, which is a large stationary part, can be sufficiently ensured.

Further, N which forms each of the divided casings
As shown in FIG. 12, the i-base alloy or the Co-base alloy can be processed into a predetermined shape from a material manufactured by forging into a columnar or block shape, and the same shape can be obtained by a single columnar or block-shaped forging material. Compared with the case of manufacturing a casing having a diameter, the ingot amount can be suppressed to a small amount, a relatively wide material can be manufactured at a time, and cost reduction can be achieved. Further, since the split casing is relatively small, the material itself may be small, a forged material having uniform properties in the thickness direction can be obtained, and a material having good properties can be manufactured.

Although the main steam stop valve has been described in the above embodiment, the present invention can be applied to a steam control valve or a reheat valve.

[0046]

As described above, in the present invention, the turbine casing, the turbine rotor, or the steam valve is divided into a plurality of parts, and at least one of the divided parts exposed to the steam of 650 ° C. or more is made of a Ni-based alloy. Alternatively, since it is formed of an austenitic steel material such as a Co-based alloy, the turbine casing and the like can withstand a high temperature of 650 ° C. or more, and a Ni-based alloy which is difficult to produce a large ingot It is possible to overcome manufacturing difficulties due to the use of such austenitic materials.
In addition, when the divided parts are integrated by bolting, it is possible to update only the necessary parts when updating the turbine rotor or casing for the purpose of improving the performance of the turbine or recovering from aging. It can also be excellent.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of one of steam turbine power generation equipment according to the present invention.

FIG. 2 is another system configuration diagram of the steam turbine power generation equipment according to the present invention.

FIG. 3 is a longitudinal sectional view of a turbine upper half casing provided with the ultra-high pressure turbine and the high pressure turbine in FIG. 1;

FIG. 4 is a longitudinal sectional view of a turbine upper half casing provided with first and second ultra-high pressure high temperature turbines in FIG. 2;

FIG. 5 is an explanatory view of manufacturing the inner casing shown in FIG. 3;

FIG. 6 is an explanatory view of connecting divided casings by welding.

FIG. 7 is an explanatory view of connecting divided rotors by welding.

FIG. 8 is a partial sectional view showing a state in which the divided casings are connected by bolting.

FIG. 9 is a partial sectional view showing a state in which the split rotors are connected by bolting.

FIG. 10 is a view showing another example in which the divided casings are connected by bolting.

FIG. 11 is a sectional view of a valve casing of the main steam stop valve.

FIG. 12 is an explanatory view of the manufacture of the valve casing shown in FIG. 11;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Ultra high pressure turbine 2 High pressure turbine 3 Medium pressure turbine 7 Boiler heater 8 1st stage reheater 9 2nd stage reheater 10a 1st ultra high pressure high temperature turbine 10b 2nd ultra high pressure high temperature turbine 11, 17 Outer casing 12, 18 Inner casing 12a, 12b, 12c, 18a, 18b, 18c Divided casing 13a, 13b, 13c, 19a, 19b, 19c Divided rotor 23, 25 bolt 26 Annular projection 28 Valve casing 28a, 28b, 28c Divided casing

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F01D 25/26 F01D 25/26 F (72) Inventor Yoichi Tsuda 2 Suehiro-cho, Tsurumi-ku, Yokohama-shi, Kanagawa 4-4, Toshiba Keihin Works Co., Ltd. (72) Inventor Takeharu Kaneko 2-4, Suehirocho, Tsurumi-ku, Yokohama, Kanagawa Prefecture, Japan Toshiba Keihin Works Co., Ltd.

Claims (12)

[Claims] In a steam turbine facility having an independent steam turbine into which steam having a steam temperature of 650 ° C. or more is introduced, a plurality of divided casings divided in a turbine axial direction are integrated with the turbine casing of the steam turbine. And at least one of the divided casings exposed to a temperature of 650 ° C. or more is represented by a Ni-based alloy containing 35% or more of Ni or a Co-based alloy containing 50% or more of Co. Characterized by being formed of an austenitic steel material,
Steam turbine equipment. 2. The steam turbine equipment according to claim 1, wherein the turbine casing is a turbine inner casing. 3. The steam turbine according to claim 1, wherein the split casing other than the split casing formed of the austenitic steel material is formed of a ferritic steel material represented by 12Cr steel. Facility. 4. The steam according to claim 1, wherein the split casing formed of the austenitic steel material is formed of a material manufactured by forging into a ring shape or a half ring shape. Turbine equipment. 5. In a steam turbine facility independently having a steam turbine into which steam having a steam temperature of 650 ° C. or higher is introduced, a plurality of split rotors divided in the axial direction are integrally connected to the rotor of the steam turbine. And at least one of the split rotors exposed to a temperature of 650 ° C. or more is formed of an austenitic steel material typified by a Ni-based alloy containing 35% or more of Ni. , Steam turbine equipment. 6. The steam turbine equipment according to claim 5, wherein the split rotor other than the split rotor formed of the austenitic steel material is formed of a ferritic steel material represented by CrMoV forged steel. 7. The steam turbine equipment according to claim 1, wherein the split casing or the split rotor is connected to and integrated with the adjacent split casing or the split rotor by welding. . 8. The steam turbine according to claim 1, wherein the split casing or the split rotor is connected to and integrated with the adjacent split casing or the split rotor by bolting to each other. Facility. 9. In a steam turbine facility having a steam turbine into which steam having a steam temperature of 650 ° C. or more is independently introduced, a steam valve casing of a main steam stop valve, a steam control valve, or a reheat valve is divided into a plurality of parts. Formed by connecting the divided parts together, and 65 of the divided parts are formed.
The main divided part exposed to a temperature of 0 ° C. or more
% Or more Ni-based alloy or Co containing 50% or more Co
A steam turbine facility formed of an austenitic steel material represented by a base alloy. 10. The steam valve casing according to claim 1, wherein each divided portion formed of an austenitic steel material is formed of a material manufactured by forging into a ring shape, a column shape, or a block shape. Item 14. The steam turbine equipment according to item 9. 11. The split casings are connected to each other by bolting, and a superposed portion which overlaps in a radial direction at a dissimilar material joining portion between the austenitic steel material and the ferritic steel material is provided. The overlapping part of the split casing consisting of
The overlapping portion of a split casing made of a ferritic steel material is disposed on the outer diameter side in the radial direction, and the gap between the overlapping portions is set to zero or a small value at room temperature. Steam turbine equipment. 12. The steam turbine equipment according to claim 11, wherein the gap between the overlapping portions in the radial direction of the dissimilar material joining portion is set to a minute value of 0.25% or less of the radius of the overlapping portion.