JP2000161006A - Steam turbine blade, steam turbine using it, steam turbine power generating plant, and high strength martensite steel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lengthen a final stage moving blade of a steam turbine, and generate power with a high efficiency by forming a length of a blade part to a specified value of more, subjecting inclination of a width direction of the blade part to be in nearly parallel with an axial direction of a rotary shaft in the vicinity of an implant part, inclining a tip end of the blade part by a specified value from an axial direction, and making the blade part of martensite steel. SOLUTION: A width direction of blade part 51 of a long blade of 40 inches or more is gradually inclined by 65 to 85 degrees from an axial direction at a tip end of the blade, and a blade implant part 52 is nearly in parallel with the axial direction of an axis. The long blade material is made of martensite steel including Co: 15 to 0.25%, Si: 0.25% or less, Mn: 0.90% or less, Cr: 8.0 to 13.0%, Ni: 2 to 3.5%, Mo: 1.5 to 3.5%, V: 0.05 to 0.35%, total quantity of one kind or two kinds of Nb and Ta is 0.02 to 0.20%, and N: 0.04 to 0.15%, in a weight ratio. The long blade has to be improved in high cycle fatigue strength simultaneously in tension strength. Accordingly, a metal texture of the blade material is made of full temper martensite texture.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel steam turbine blade, and more particularly to a steam turbine blade for a low pressure steam turbine.
The present invention relates to a low-pressure steam turbine using 2% Cr-based steel and a steam turbine power plant using the same.

[0002]

2. Description of the Related Art At present, 12Cr
-Mo-Ni-VN steel is used. In recent years, it has been desired to improve the thermal efficiency of gas turbines from the viewpoint of energy saving, and to reduce the size of equipment from the viewpoint of space saving.

[0003] To improve the thermal efficiency and make the equipment compact, it is effective means to increase the length of the steam turbine blades. Therefore, the blade length of the last stage of the low-pressure steam turbine tends to increase year by year. Along with this, the operating conditions of the blades of the steam turbine have become severe, and the strength of the conventional 12Cr-Mo-Ni-VN steel is insufficient, and a material having higher strength is required. As the strength of the long wing material, a tensile strength, which is a basic mechanical property, is required.

Further, from the viewpoint of ensuring safety against fracture, high strength and high toughness are required.

[0005] The tensile strength of the conventional 12Cr-Mo-Ni-
Ni-based alloys and Co-based alloys are generally known as structural materials higher than VN steel (martensitic steel), but they are inferior in hot workability, machinability and vibration damping properties.
It is not desirable as a wing material.

Further, a last-stage blade material for a low-pressure steam turbine, and a low-pressure steam turbine and a steam turbine power plant using the same are disclosed in WO97 / 30272.

[0007]

However, the aforementioned publication discloses a low-pressure steam turbine as a last stage rotor blade having a rotation speed of 3000 rpm.
wing length 43 inches for m, 3 for 3600 rpm
Although a 5.8-inch blade is shown, there is no specific disclosure for longer blade lengths, nor is there any disclosure of the blade shape or low pressure steam turbine size.

An object of the present invention is to provide a wing length of 3000.
Provide a steam turbine blade made of martensite steel capable of achieving 46 inches or more for rpm or 38 inches or more for 3600 rpm, a low-pressure steam turbine and a steam turbine power plant using the same, and a high-strength martensitic steel. To be.

[0009]

According to the present invention, a wing portion having a wing length of 4 is provided.
0 inches or more, the inclination in the width direction of the wing portion is substantially parallel to the axial direction of the rotation axis near the implanted portion, the tip of the wing portion is tilted by 65 to 85 degrees with respect to the axial direction, A steam turbine blade characterized by being made of martensitic steel. The angle is preferably 70 to 80 degrees.

According to the present invention, a 20 ° C. V notch impact value (kg-m
/ Cm ² ) y is a martensitic steel having a tensile strength at room temperature (kg / mm ² ) x equal to or greater than a value determined by the following equation.

Y = -0.29x + 45 In the present invention, the wing length is 45 inches or more for 3000 rpm or 37.5 inches or more for 3600 rpm.
9 or more and 37.5 for 45 inches or more
A steam turbine blade characterized by being a fork type having seven or more inches or more or an inverted Christmas tree type having four or more projections and made of martensitic steel.

In the present invention, the length of the wing is 40 inches or more, and the width of the implanted portion with respect to the width of the tip of the wing is 2.1 to 2.2.
A steam turbine blade characterized in that the blade is made of martensite steel that is five times as large.

According to the present invention, the wing length is 45 inches or more for 3000 rpm or 37.5 inches or more for 3600 rpm, an erosion prevention shield portion is provided on the leading side of the tip of the wing portion, and the implant portion is a fork. The steam turbine blade is characterized in that a plurality of fixing pin insertion holes for a rotor shaft are provided in a plurality of stages, and the diameter of the insertion hole is larger on the wing side than on the opposite side and made of martensitic steel.

According to the present invention, a high-pressure turbine, a medium-pressure turbine and two low-pressure turbines are connected in tandem, and the steam inlet temperature to the high-pressure turbine and the medium-pressure turbine is 593 ° C. or more and the rotation speed is 3000 or 3600 rpm. In the steam turbine power plant, the last stage blade of each of the low pressure turbines has a blade length (inch) × the number of revolutions (rpm) of 129000 or more, is made of martensitic steel, and has an average of the last stage blade. The diameter is 3520 mm or more, preferably 3600 to 3750 mm for the 3000 rpm or 2930 mm or more, preferably 300 mm for the 3600 rpm.
It is characterized in that it is 0 to 3130 mm, and it is preferable to use the above-mentioned steam turbine blade as a final stage rotor blade.

According to the present invention, a high-pressure turbine, a low-pressure turbine, and a generator, and an intermediate-pressure turbine, a low-pressure turbine, and a generator are coupled in tandem. Is 3000 or 3600 rpm, the final stage rotor blade of any of the low-pressure turbines has a blade length (inch) × the number of revolutions (rpm) of 129000 or more, and is made of martensitic steel. The average diameter of the final stage rotor blade is 2800 mm or more for the above 3000 rpm, preferably 3000 to 3040 mm, or 2 to 3600 rpm.
It is 330 mm or more, preferably 2400 to 2530 mm, and it is preferable to use the above-mentioned steam turbine blade for the last stage rotor blade.

According to the present invention, a high pressure / intermediate pressure integrated turbine and one or two low pressure turbines are connected in tandem.
In a steam turbine power plant in which the steam inlet temperature to the high-pressure section and the medium-pressure section is 593 ° C. or higher and the number of revolutions is 3000 rpm or 3600 rpm, the last stage rotor blade of each of the low-pressure turbines has a blade length (inch) × The rotation speed (rpm)] is 129000 or more, and is made of martensitic steel, and the average diameter of the final stage rotor blade is 2540 mm or more, preferably 2610 to 2770 mm for the 3000 rpm, or 2120 mm or more, preferably 217 mm for the 3600 rpm.
It is characterized in that it is 0 to 2310 mm, and it is preferable to use the above-mentioned steam turbine blade as the last stage rotor blade.

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 a casing for holding the stationary blade.
In a low-pressure steam turbine having a rotation speed of 3000 rpm or 3600 rpm, the moving blade has a left-right symmetrical five-stage or more each stage, and has a double-flow structure in which the first stage is implanted in the center of the rotor shaft, and the last-stage blade is [ Blade length (inch) × the number of revolutions (rpm)] is 129000 or more, is made of martensite steel, and the average diameter of the final stage rotor blade is 3000
3520 rpm or more or 3930 rpm or more and 2930 mm or more. The final stage rotor blade has a [wing length (inch) × the number of revolutions (rpm)] of 129000 or more and is made of martensitic steel. The average diameter of the moving blade is 2800 mm or more for the above 3000 rpm or 2330 mm or more for the above 3600 rpm, or the last stage moving blade is [wing length (inch) × the number of revolutions (rpm)].
Is more than 129000 and is made of martensitic steel, and the average diameter of the last stage blade is 25 with respect to the 3000 rpm.
A low-pressure steam turbine characterized by being at least 40 mm or at least 2120 mm at 3600 rpm.

The present invention relates to a low-pressure steam turbine having a rotor shaft, a moving blade implanted on the rotor shaft, a stationary blade for guiding the flow of steam to the rotating blade, and a casing for holding the stationary blade. The last stage of the moving blade is constituted by the steam turbine blade described above.

The present invention relates to a method for preparing C19.
%, Si 0.25% or less, Mn 0.90% or less, Cr 8.
0 to 13.0%, Ni 2 to 3.5%, Mo 1.5 to 3.5
%, V 0.05 to 0.35%, one or two of Nb and Ta
0.02 to 0.20% total seed and 0.04 to 0.1 N
High strength martensitic steel characterized by containing 5%.

The present invention provides a steam turbine power plant having a high-pressure turbine, a medium-pressure turbine, and a low-pressure turbine separately, wherein the high-pressure turbine and the medium-pressure turbine are tandem with respect to the blade length of the last-stage moving blade of the low-pressure turbine. The ratio of the sum of the distances between the bearings connected to each other and the distance between the bearings of the two low-pressure turbines connected in tandem is 26 to 30.
The ratio of the distance between the bearings of the high-pressure turbine to the blade length of the last stage rotor blades of the low-pressure turbine is 3.5 to 3.5.
6.0, wherein the ratio of the distance between the bearings of the intermediate pressure turbine to the blade length of the last stage rotor blade of the low pressure turbine is 4.0 to 6.0, and the last stage rotor blade of the low pressure turbine. The ratio of the total distance between the bearings of the two low-pressure turbines connected in tandem to the blade length of the tandem is 15.5 to 17.5.
Any or a combination of the above is preferred.

According to the present invention, in a steam turbine power plant, a distance between bearings in which the high-pressure turbine and the medium-pressure turbine are connected in tandem with respect to a rated output (MW) of the power plant, and two low-pressure turbines connected in tandem The ratio of the total distance between bearings (mm) is 28.0 to 32.
0, the ratio of the bearing distance (mm) of the high pressure turbine to the rated output (MW) of the power plant is 3.5 to 6.5, and the medium pressure turbine is The ratio of the distance between bearings (mm) of the intermediate pressure turbine to the rated output (MW) of the low pressure turbine is 4.0 to 7.0, and the low pressure turbine is the rated output (MW) of the power plant.
It is preferable that the ratio of the distance (mm) between the bearings of the two low-pressure turbines coupled in tandem to the above is 16.0 to 19.0 or any combination thereof.

The present invention relates to a steam turbine power plant including a high-to-medium pressure integrated turbine and a low-pressure turbine in which a high-pressure turbine and a medium-pressure turbine are integrated. The ratio of the sum of the distance between the bearings of the high-to-medium pressure integrated turbine and the distance between the bearings of the two low-pressure turbines coupled in tandem is 24-28, and the height-to-middle ratio with respect to the blade length of the last stage blade of the low-pressure turbine. The ratio of bearing distance of pressure integrated turbine is 5.5
And the ratio of the 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 15.0 to 17.5. Or combinations are preferred.

The present invention relates to a steam turbine power plant including a high-to-medium pressure integrated turbine and a low-pressure turbine in which a high-pressure turbine and a medium-pressure turbine are integrated. The ratio of the total distance between the bearings of the high-to-medium pressure integrated turbine and the distance between the bearings of one of the low-pressure turbines is 11.5 to 15.5. The ratio of the distance between the bearings of the pressure-integrated turbine is 4.5 to 6.0, and the ratio of the distance between the bearings of the one low-pressure turbine to the blade length of the last stage rotor blade of the low-pressure turbine is 4.5. ~
Any or a combination of 6.5 is preferred.

The present invention relates to a steam turbine power plant including a high-to-medium pressure integrated turbine and a low-pressure turbine in which a high-pressure turbine and a medium-pressure turbine are integrated, wherein the high-to-medium pressure integrated power with respect to a rated output (MW) of the power plant is provided. The ratio of the total distance (mm) between the bearing distance of the turbine and the bearing distance of the two low-pressure turbines coupled in tandem is 35.0 to 35.0.
39.5, the rated output of the power plant (M
W) Distance between bearings of high- and medium-pressure integrated turbine (mm)
And the ratio of the total distance (mm) between the bearings of the two low-pressure turbines connected in tandem to the rated power (MW) of the power plant is 2
Any or a combination of 1.0 to 25.5 is preferred.

The present invention relates to a steam turbine power plant including a high-to-medium pressure integrated turbine and a low-pressure turbine in which a high-pressure turbine and a medium-pressure turbine are integrated, wherein the high-to-medium pressure integrated power with respect to a rated output (MW) of the power plant is provided. The ratio of the total distance between the bearings of the turbine and the distance between the bearings of one of the low-pressure turbines is 22.0 to 26.5, and the ratio between the bearings of the high and medium pressure integrated turbine with respect to the rated output (MW) of the power plant. The ratio of the distance (mm) is 8.0 to 11.0, and the ratio of the bearing distance (mm) of the one low-pressure turbine to the rated output (MW) of the power plant is 8.5.
Any or a combination of 〜11.5 is preferred.

The above requirements are applicable to the following invention.

According to the present invention, in the above-described steam turbine power plant, 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 moving blade of 593 to 593.
660 ° C (preferably 610 to 620 ° C, 620 to 630
C., 630 to 640 ° C.), the low-pressure turbine has a steam inlet temperature to the first stage rotor blade of 350 to 400 ° C., and the steam inlet temperature of the high-pressure turbine and the medium-pressure turbine or the high-medium-pressure turbine. The rotor shaft or rotor shaft, rotor blades, stator blades and inner casing which are exposed to all are composed of high-strength martensitic steel containing 8 to 13% by weight of Cr, or among them, the first or second stage of the rotor blades, Alternatively, it is preferable that up to three stages are made of a Ni-based alloy.

The present invention has a rotor shaft, a rotor blade implanted on the rotor shaft, a stationary blade for guiding the flow of steam to the rotor blade, and an inner casing for holding the stationary blade. The temperature at which steam enters the first stage of the bucket is 59
3 to 660 ° C and a pressure of 250 kgf / cm ² or more (preferably 246 to 316 kgf / cm ² ) or 170 to 200 kgf / cm
² , wherein the rotor shaft or the rotor shaft and at least the first stage of the moving blade and the stationary blade have respective steam temperatures (preferably 610 ° C., 625 ° C., 640 ° C., 650 ° C., 660 ° C.).
° C.) 10 ⁵ h creep rupture strength at a temperature corresponding to the 10 kgf / mm ² or more (preferably Cr8.5~13 wt% is 17 kgf / mm ² or higher) (preferably 10.5
(11.5% by weight) and a high-strength martensitic steel having a fully tempered martensite structure, or the first stage, the second stage, or the third stage of the bucket is made of Ni.
A base alloy, and the inner casing has a 10 ⁵ hour creep rupture strength of 10 k at a temperature corresponding to each of the steam temperatures.
The steam discharged from a high-pressure steam turbine, a medium-pressure steam turbine or a high-pressure side turbine made of a martensitic cast steel containing 8 to 9.5% by weight of Cr having a gf / mm ² or more (preferably 10.5 kgf / mm ² or more) It is preferable to use a high-to-medium pressure integrated steam turbine which heats the fuel and heats it to a temperature equal to or higher than the high-pressure side inlet temperature and sends it to the medium pressure side turbine.

In the high-pressure turbine and the intermediate-pressure turbine or the high- and intermediate-pressure integrated steam turbine, the first stage of the rotor shaft or at least one of the moving blade and the stationary blade is C
0.05 to 0.20%, Si 0.6% or less, preferably 0.1
5% or less, Mn 1.5% or less, preferably 0.05 to 1.
5%, Cr 8.5-13%, preferably 9.5-13%,
Ni 0.05 to 1.0%, V 0.05 to 0.5%, preferably 0.05 to 0.35%, at least one of Nb and Ta 0.01 to 0.20%, N 0.01 to 0. 0.1%, preferably 0.01 to 0.06%, Mo 1.5% or less, preferably 0.1%
0.5 to 1.5%, W 0.1 to 4.0%, preferably 1.0 to 1.0%
4.0%, Co 10% or less, preferably 0.5 to 10%,
B 0.03% or less, preferably 0.0005 to 0.03%
High strength martensitic steel containing 78% or more of Fe is preferable, and preferably corresponds to a steam temperature of 593 to 660 ° C, or C 0.1 to 0.25%, Si 0.6
%, Mn 1.5% or less, Cr 8.5-13%, Ni 0.5%
0.05 to 1.0%, V 0.05 to 0.5%, W 0.10 to 0.1%.
65%, at least one of Nb and Ta 0.01 to 0.2
0%, Al 0.1% or less, Mo 1.5% or less, N 0.02
High-strength martensitic steel with 5 to 0.1% and 80% or more Fe is preferred and preferably corresponds to 600 to less than 620 ° C. The inner casing is C by weight
0.06-0.16%, Si 0.5% or less, Mn 1% or less,
Ni 0.2-1.0%, Cr 8-12%, V 0.05-0.5.
35%, at least one of Nb and Ta 0.01 to 0.1
5%, N 0.01 to 0.8%, Mo 1% or less, W1 to 4
%, B 0.0005 to 0.003%, and is preferably made of a high-strength martensitic steel having 85% or more of Fe.

In the high-pressure steam turbine according to the present invention, the rotor blade has at least nine stages, preferably at least ten stages, the first stage has a double flow, and the rotor shaft has a bearing center distance (L) of 50 or more.
The minimum diameter (D) at the portion where the stationary blade is provided is 660 mm or more (preferably 680 to 740 mm), and the (L /
It is preferable to comprise a high-strength martensitic steel containing 9 to 13% by weight of Cr whose D) is 6.8 to 9.9 (preferably 7.9 to 8.7).

The medium-pressure steam turbine according to the present invention has a double-flow structure in which the rotor blades have six stages or more in a symmetrical manner, and the first stage is implanted at the center of the rotor shaft. The center-to-center distance (L) is 5000 mm or more (preferably 5100 to 6500 mm), and the minimum diameter (D) at the portion where the stator vanes are provided is 630 mm or more (preferably 650 to 710 mm). ) Is 7.0
9.1 to 9.2 (preferably 7.8 to 8.3)
It preferably consists of a high strength martensitic steel containing 3% by weight.

[0032] In the low-pressure steam turbine according to the present invention, the moving blade has left-right symmetrically five or more stages, preferably six or more stages,
The rotor shaft has a double-flow structure in which a first stage is implanted at a center portion thereof. The rotor shaft has a bearing center distance (L) of 6500 mm or more (preferably 6600 to 7500 mm) and a minimum at a portion where the stationary blade is provided. Diameter (D) is 75
0 to 1300 mm (preferably 760 to 900 mm), and the (L / D) is 5 to 10, preferably 7 to 10
(More preferably 8.0 to 9.0).
Ni-Cr-Mo-V containing 25 to 4.25% by weight
Those made of low alloy steel are preferred.

Further, according to the present invention, in the above-mentioned steam turbine power plant, 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 moving blade of 593 to 660 ° C., and the low-pressure turbine has the first-stage moving blade. And the metal temperature of the first stage moving blade implanted portion of the rotor shaft of the high pressure turbine and the metal temperature of the first stage moving blade is 40 ° C. higher than the steam inlet temperature to the first stage moving blade of the high pressure turbine. The temperature of the first stage rotor blades and the metal temperature of the first stage rotor blades of the rotor shaft of the intermediate pressure turbine should be kept below (preferably 20 to 35 ° C. lower than the steam temperature). It is preferable that the temperature is not lower than 75 ° C. or higher (preferably lower by 50 to 70 ° C. than the steam temperature) than the inlet temperature of steam.

Further, the present invention relates to a coal-fired boiler, a steam turbine driven by steam obtained by the boiler, and a single unit or two driven by the steam turbine.
In a coal-fired thermal power plant provided with at least two, preferably two generators having a power output of at least 1000 MW, the steam turbine has the above-mentioned configuration, and the first stage rotor of the high-pressure turbine is heated by the superheater of the boiler. 3 ° C or more (preferably 3 to 10 ° C,
More preferably, the steam heated to a high temperature flows into the first stage rotor of the high-pressure turbine, and the steam exiting the high-pressure turbine is sent to the first stage rotor of the intermediate-pressure turbine by the reheater of the boiler. Is heated to a temperature 2 ° C. or higher (preferably 2 to 10 ° C., and more preferably 2 to 5 ° C.) higher than the steam inlet temperature of the steam turbine, flows into the first stage moving blades of the intermediate-pressure turbine, and exits from the intermediate-pressure turbine. Is preferably 3 ° C. or more (preferably 3 to 10 ° C.) from the steam inlet temperature to the first-stage bucket of the low-pressure turbine by the boiler's economizer.
(Preferably 3 to 6 ° C.), and is preferably heated to a high temperature to flow into the first stage blade of the low-pressure turbine.

In the low-pressure steam turbine described above, the steam inlet temperature to the first-stage bucket is preferably 350 to 400 ° C. (preferably 360 to 380 ° C.).

In the high-pressure steam turbine described above, the moving blade has 7 stages or more (preferably 9 to 12 stages), and the blade portion has a length of 25 to 180 mm from the upstream side to the downstream side of the steam flow. The diameter of the implanted portion of the moving blade is larger than the diameter of the portion corresponding to the stationary blade, and the axial width of the implanted portion is three or more steps (preferably 4 to 7 steps) on the downstream side compared with the upstream side. The ratio to the wing length is 0.2 to 1.6 (preferably 0.30 to 1.6).
1.30, and more preferably 0.65 to 0.95), decreasing from the upstream side to the downstream side, and the ratio of the wing length of each adjacent stage is 2.3 or less, and the ratio is less than 2.3. The wing portion length is gradually increased on the downstream side, and the wing portion length is larger on the downstream side than on the upstream side, and the axial width of a portion of the rotor shaft corresponding to the stationary blade portion is on the downstream side on the upstream side. The ratio becomes smaller stepwise in two or more stages (preferably two to four stages), and gradually decreases as the ratio of the moving blade to the downstream wing portion length decreases to the downstream side in a range of 4.5 or less. Any or a combination of the above is preferred.

In the above-mentioned medium-pressure steam turbine, the moving blade has a double flow structure having six or more stages (preferably 6 to 9 stages) symmetrically, and the blade length is 60 to 300 mm from the upstream side to the downstream side of the steam flow. The diameter of the implanted portion of the rotor blade of the rotor shaft is larger than the diameter of a portion corresponding to the stationary blade, and the axial width of the implanted portion is two or more steps (preferably 2 steps) at the downstream side as compared to the upstream side. ~ 6 stages), and the ratio to the wing length is 0.1%.
35 to 0.80 (preferably 0.5 to 0.7), decreasing from the upstream side to the downstream side, and the length of the adjacent wings is larger at the downstream side than at the upstream side, The ratio is 1.3 or less (preferably 1.1 to 1.
In step 2), the width of the rotor shaft gradually increases on the downstream side, and the axial width of the portion corresponding to the stationary blade portion of the rotor shaft is two or more steps (preferably 3 steps) on the downstream side as compared with the upstream side.
~ 6 stages), and the downstream side of the rotor blade is in the downstream side in a ratio of 0.80 to 2.50 (preferably 1.0 to 2.0). It is preferable that the ratio is gradually reduced according to any one or combination of the above.

In the above-described low-pressure steam turbine according to the present invention, the moving blades are symmetrically arranged in six or more stages (preferably, eight stages).
10 to 10 stages) having a double-flow structure and a blade length of 80 to 1300 mm from the upstream side to the downstream side of the steam flow, wherein the diameter of the rotor blade impeller portion is larger than the diameter of the portion corresponding to the stator blade. Preferably, the axial width of the implanted portion is gradually increased in the downstream side as compared with the upstream side in three or more stages (more preferably, four to seven stages), and the ratio to the wing length is 0.1. 2 to 0.7 (preferably 0.3 to 0.55), decreasing from the upstream side to the downstream side, and the length of the wing portion of each adjacent stage is larger at the downstream side than at the upstream side. The ratio is gradually increased in the downstream side in a range of 1.2 to 1.8 (preferably 1.4 to 1.6), and the stationary blade portion of the rotor shaft The axial width of the portion corresponding to Compared with the upstream side, it is preferably increased stepwise in three or more stages (more preferably 4 to 7 stages), and the ratio of the moving blade to the adjacent downstream blade portion length is 0.2 to 1.4 (preferably Any one or combination of the ratios gradually decreasing toward the downstream side in the range of 0.25 to 1.25, particularly 0.5 to 0.9) is preferable.

In the above-described high-pressure steam turbine, the rotor shaft has a portion corresponding to the stationary blade having a diameter smaller than that of the portion corresponding to the rotor blade implantation portion, and an axial width of the diameter corresponding to the stationary blade. Means that the upstream side of the steam flow is at least two stages (preferably two to four stages) compared to the downstream side
The width between the last stage of the moving blade and the front thereof is 0.75 to 0.95 times the width between the second stage and the third stage of the moving blade ( It is preferably 0.8 to 0.9 times, more preferably 0.82 to 0.88), and the width of the rotor shaft in the axial direction of the rotor blade implant portion is smaller on the downstream side of the steam flow than on the upstream side. At least three stages (preferably 4 to
7), and the axial width of the last stage of the rotor blade is 1 to 1 with respect to the axial width of the second stage.
It is preferably twice (preferably 1.4 to 1.7 times).

In the above-mentioned medium pressure steam turbine, the rotor blade has six or more stages, and the rotor shaft has a portion corresponding to the stationary blade having a diameter smaller than that of the portion corresponding to the rotor blade implantation portion. The axial width of the diameter corresponding to the stationary blade is preferably increased stepwise at two or more stages (more preferably 3 to 6 stages) on the upstream side of the steam flow as compared with the downstream side. The width between the last stage and the front of the blade is 0.5 to 0.5 of the width between the first stage and the second stage of the bucket.
0.9 times (preferably 0.65 to 0.75 times), and the width of the rotor shaft in the axial direction of the moving blade portion implanted portion is preferably two stages on the downstream side of the steam flow as compared with the upstream side. As described above (preferably in 3 to 6 stages), the axial width of the last stage of the rotor blade is 0.8 to 2 times (preferably 1 to 2) the axial width of the first stage. .2 to 1.5
Times).

In the low-pressure steam turbine described above, the moving blade has a double flow structure having eight stages or more symmetrically, and the rotor shaft has a portion corresponding to the stationary blade having a diameter corresponding to the moving blade implanted portion. The axial width of the diameter smaller than the diameter of the portion and corresponding to the stationary blade is preferably three or more stages (more preferably four to seven stages) on the upstream side of the steam flow as compared with the downstream side. The width between the last stage of the moving blade and the front stage is 1.5 to 3.0 times (preferably 2.0) the width between the first stage and the second stage of the moving blade.
The width of the rotor shaft in the axial direction of the rotor blade implanted portion is preferably three or more stages on the downstream side of the steam flow as compared with the upstream side (more preferably 4 to 7 times).
And the axial width of the last stage of the rotor blade is 5 to 8 times (preferably 6.2 to 7.0 times) the axial width of the first stage. Preferably it is.

In the rotor material of the high-pressure, medium-pressure and high-medium-pressure turbine according to the present invention, the Cr equivalent is set to 4 to 8 in order to obtain a high-temperature strength, a low-temperature toughness and a high fatigue strength as a fully tempered martensite structure. It is preferable to adjust the components.

In the high / intermediate pressure integrated steam turbine according to the present invention, the high pressure side moving blade has 7 or more stages, preferably 8 or more stages, and the medium pressure side moving blade has 5 or more stages, preferably 6 or more stages. Has a bearing center distance (L) of 6000 mm or more (preferably 6100 to 7000 mm) and a minimum diameter (D) at a portion where the stationary blade is provided is 660 mm or more (preferably 620 to 760 mm); / D) is 8.
0 to 11.3 (preferably 9.0 to 10.0) Cr
It is preferred to be made of a high-strength martensitic steel containing 9 to 13% by weight.

The blade for a low-pressure turbine according to the present invention has a double-flow structure having five or more stages, preferably six or more stages in a bilaterally symmetric manner, and a blade length of 8 from the upstream side to the downstream side of the steam flow.
0 to 1300 mm, the diameter of the blade portion of the rotor shaft is larger than the diameter of the portion corresponding to the stationary blade, and the width of the root portion in the axial direction of the blade portion is widened. The width is larger than the width of the portion, and gradually decreases from the downstream side to the upstream side, the ratio to the wing length is 0.25 to 0.80, and the wing length of each adjacent stage is The downstream side is larger than the upstream side, and the ratio is in the range of 1.2 to 1.7. The blade length is gradually increased on the downstream side, and the rotor blade of the rotor shaft is It is preferable that the axial width of the root portion of the implant portion is larger in the downstream side than in the upstream side in at least three stages, and is wider or wider than the width of the wing implant portion.

In the high- and medium-pressure integrated steam turbine according to the present invention, the moving blade on the high pressure side has 6 stages or more, preferably 7 stages or more, and the blade length is 25 mm to 200 mm from the upstream side to the downstream side of the steam flow. An implant diameter of the rotor blade of the rotor shaft is larger than a diameter of a portion corresponding to the stationary blade,
The width of the root portion in the axial direction of the implanted portion is gradually larger on the upstream side than on the downstream side, and the ratio to the wing length is 0.20 to 1.60, preferably 0.25 to 1.30, and From the side to the downstream, the blades on the medium pressure side have five or more stages symmetrically, the blade length is 100 to 350 mm from the upstream side to the downstream side of the steam flow, and the rotor shaft has The diameter of the implanted portion of the rotor blade is larger than the diameter of a portion corresponding to the stationary blade, and the axial width of the root portion of the implanted portion is larger on the downstream side than on the upstream side except for the last stage, and the blade length The ratio to the height is 0.3
5 to 0.80, preferably 0.40 to 0.75, decreasing from the upstream side to the downstream side, the ratio of the wing length of each adjacent stage is 1.05 to 1.35, The blade length is gradually larger on the downstream side than on the upstream side, the intermediate pressure section has five or more blades, and the blade length is 100 to 350 mm from the upstream side to the downstream side of the steam flow. The length of the adjacent wings is greater on the downstream side than on the upstream side, and the ratio is 1.10 to 1.30, and gradually increases on the downstream side. The diameter of the portion corresponding to the stationary blade is smaller than the diameter of the portion corresponding to the bucket implant, and the axial width of the root of the implant of the bucket is the largest in the first stage, and the upstream side of the steam flow. 2 or more stages, preferably 3 or more stages, The rotor blade on the medium pressure side has five or more stages, and the rotor shaft has a portion corresponding to the stationary blade having a diameter smaller than that of the portion corresponding to the rotor blade implantation portion; The width in the axial direction of the root portion of the implanted portion is preferably different from the downstream side on the upstream side of the steam flow preferably in four or more stages, and the first stage of the blade is more than two stages, and the last stage is another stage. First stage and 2 larger than stage
It is preferable that any one of the steps is divergent or a combination thereof. The internal casing material for high-, medium-, and high-pressure turbines according to the present invention is adjusted in alloy composition so as to have a tempered martensite structure of 95% or more (δ ferrite of 5% or less) to provide high high-temperature preparation, low-temperature toughness and high temperature. In order to obtain the fatigue strength, the Cr equivalent calculated assuming the content of each element of the following formula as% by weight is adjusted to 4 to 10 to 8 to 12%.
In the case of Cr cast steel, it is particularly preferable that the creep rupture strength at 625 ° C. and 10 ⁵ h is 10 kgf / mm ² or more and the impact absorption energy at room temperature is 1 kgf-m or more.

Cr equivalent = Cr + 6Si + 4Mo + 1.5
W + 11V + 5Nb-40C-30N-30B-2Mn
-4Ni-2Co + 2.5Ta (1) Components of long blade material for low pressure steam turbine The last stage rotor blade for low pressure turbine according to the present invention has the following relationship with the low pressure steam turbine having the above-mentioned specific relationship. It has a composition. The composition is, by weight ratio, C 0.15 to 0.25%, Si 0.25% or less, M
n 0.90% or less, Cr 8.0-13.0%, Ni 2-3.
5%, Mo 1.5-3.5%, V 0.05-0.35%,
The total amount of one or two of Nb and Ta is from 0.02 to 0.2
It is preferable to consist of martensitic steel containing 0% and 0.04 to 0.15% of N.

The long blade of the steam turbine must have high tensile strength and high cycle fatigue strength in order to withstand high centrifugal stress and vibration stress caused by high-speed rotation.
Therefore, the metal structure of the blade material must be a fully tempered martensitic structure, since the presence of harmful δ ferrite significantly reduces the fatigue strength.

The composition of the steel of the present invention must be adjusted so that the Cr equivalent calculated by the above-mentioned formula becomes 10 or less, and it is necessary that the steel does not substantially contain a δ ferrite phase.

The tensile strength of the long wing material is 130 kgf / mm ² or more, preferably 138.5 kgf / mm ² or more.

Further, in order to obtain a homogeneous and high-strength steam turbine long blade material, a refining heat treatment is performed after melting and forging.
00 ° C to 1100 ° C (preferably 1000 to 1055
C.) for 0.5 to 3 hours, and then quenched by quenching to room temperature (especially oil quenching is preferred), followed by tempering at 550 to 620 ° C., especially 550 to 570 ° C.
C. for 1 to 6 hours, followed by primary tempering to cool to room temperature and 560 to 590.degree. C., preferably 1 to 6 hours.
It is preferable to perform two or more tempering heat treatments of a secondary tempering of cooling to room temperature after heating and holding for a time. The secondary tempering temperature is preferably higher than the primary tempering temperature.
Preferably, the temperature is increased by 0 to 30 ° C, more preferably by 15 to 20 ° C.

The present invention relates to a low pressure turbine last stage blade having a length of 3600 rpm for 60 cycle power generation and a 5600 rpm steam turbine.
For a 3000rpm steam turbine for zero cycle power generation,
As described above, the value of [wing length (inch) × rotation speed (rpm)] is 129000 or more. 909 mm (35.8 ") or more for 3600 rpm, preferably 965 mm
mm (38 ") to 1067 mm (42"), more preferably 1016 mm (40 ") or less, and for 3000 rpm, 1092 mm (43") or more, preferably 1168 mm.
(46 ") to 1270 mm (50"), more preferably 121
9 mm (48 ") or less.

The average diameter of the last stage rotor blade described below according to the present invention is 43 ″, 46 ″ blade and 36
Although 36 "and 38" blades are shown for 00 rpm, it is possible to set the values for the 50 "blade at 3000 rpm and the 40" blade at 3600 rpm on the extension of the values shown in the embodiments described later.

Further, in the blade material made of the heat-resistant steel of the present invention, in order to obtain high strength, low-temperature toughness and fatigue strength by adjusting the alloy composition so as to have a whole martensite structure, the Cr equivalent calculated as described above is obtained. Is preferably adjusted to 4 to 10. C is 0.15% or more in order to obtain a high tensile strength, and if C is excessively increased, toughness is reduced. In particular, from 0.19
0.25% is preferable, and 0.19 to 0.23% is more preferable.

Si is a deoxidizing agent, and Mn is a desulfurizing / deoxidizing agent added during melting of steel, and is effective even in a small amount. Si is a δ-ferrite forming element, and if added in a large amount, causes harmful δ-ferrite formation which deteriorates fatigue and toughness, so is preferably not more than 0.25%. In addition,
According to the carbon vacuum deoxidation method, the electroslag melting method, or the like, there is no need to add Si, and it is preferable to add no Si. In particular, it is preferably 0.10% or less, more preferably 0.05% or less.

The addition of a small amount of Mn improves the toughness, but the addition of a large amount lowers the toughness.
In particular, since Mn is effective as a deoxidizing agent, it is preferably at most 0.4%, more preferably at most 0.2%, from the viewpoint of improving toughness.

Cr enhances corrosion resistance and tensile strength.
% Or more causes formation of a δ ferrite structure.
If it is less than 8%, the corrosion resistance and tensile strength are insufficient, so that C
r is preferably 8 to 13%. Especially 10.5 from the point of strength
~ 12.5% is more preferable.

Mo has the effect of increasing the tensile strength by the action of solid solution strengthening and precipitation strengthening. Mo has an insufficient effect of improving the tensile strength, and if it is 3% or more, it causes the formation of δ ferrite. Therefore, Mo is preferably 1.5 to 3.5%. Especially 1.8 ~
2.7%, more preferably 2.0-2.5%. Note that W and Co have the same effect as Mo, and can be contained up to the same content at the upper limit for higher strength.

V and Nb precipitate carbides to increase tensile strength and also have an effect of improving toughness. V 0.05%, Nb
If the content is less than 0.02%, the effect is insufficient.
%, Nb 0.2% or less is preferable from the viewpoint of suppressing the formation of δ ferrite. In particular, V is 0.15 to 0.30%, more preferably 0.25 to
0.30%, Nb is 0.10 to 0.20%, more than 0.12 to
0.18% is preferred. Ta can be added in exactly the same manner as in place of Nb, and the total content can be made the same in the case of composite addition.

Ni has the effect of increasing the low temperature toughness and preventing the formation of δ ferrite. This effect is insufficient when Ni is less than 2%, and the effect is saturated when the addition exceeds 3.5%. In particular, 2.6 to 3.2% is preferable.

N is effective in improving the tensile strength and preventing the formation of δ ferrite, but if it is less than 0.04%, the effect is not sufficient, and if it exceeds 0.15%, the toughness is reduced. In particular, excellent characteristics can be obtained in the range of 0.06 to 0.10%.

The reduction of Si, P and S has the effect of increasing the low-temperature toughness without impairing the tensile strength, and it is desirable to reduce it as much as possible. From the viewpoint of improving low-temperature toughness, Si is 0.25% or less, preferably 0.1% or less, P 0.015% or less,
It is preferably at most 0.015%. In particular, it is desirable that Si is 0.05% or less, P is 0.010% or less, and S is 0.010% or less. The reduction of Sb, Sn and As also has the effect of increasing the low-temperature toughness, and it is desirable to reduce it as much as possible. However, from the point of the current steelmaking technology level, Sb 0.0015% or less, Sn0.
01% or less and As is limited to 0.02% or less. In particular, Sb 0.001% or less, Sn 0.005% and As
0.01% or less is desirable.

Further, in the present invention, the Mn / Ni ratio is set to 0.11 or less, and Ti, Zr, Hf, Ta
It is preferable to use one or a combination of two, three, and four types of MC carbide-forming elements such as the above in a total of 0.5% or less.

In the heat treatment of the material of the present invention, first, the material is uniformly heated to a temperature sufficient to transform completely into austenite, at least 1000 ° C. and at most 1100 ° C., and rapidly cooled (preferably oil-cooled).
Next, it is heated and maintained at a temperature of 550 to 570 ° C. (first tempering), and then heated and maintained at a temperature of 560 to 680 ° C. (secondary tempering) to obtain a fully tempered martensite structure. Is preferred. The second tempering is the first
The temperature is higher than the next tempering temperature.

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

The last-stage steam turbine blade for a low-pressure steam turbine according to the present invention is preferably related to the above-described low-pressure turbine.
9 to 0.25%, Si 0.25% or less, Mn 0.90% or less, Cr 8.0 to 13.0%, Ni 2 to 3.5%, Mo
1.5-3.5%, V 0.05-0.35%, Nb and Ta
And the total amount of one or two is 0.02 to 0.20%, and N
It is made of martensitic steel containing 0.04 to 0.15%.

(2) A high- and medium-pressure or high-to-medium pressure integrated rotor shaft, moving blades, stationary blades, internal casing fastening bolts, and a middle pressure part first stage diaphragm of the 620 to 660 ° C. steam turbine of the present invention. The composition of the site-based heat-resistant steel will be described. In particular, it is suitable for a rotor shaft.

C is an indispensable element for securing quenchability, precipitating carbides during the tempering heat treatment process and increasing the high-temperature strength, and 0.05% for obtaining high tensile strength.
The above elements are necessary. However, if the content exceeds 0.25%, the metal structure becomes unstable when exposed to a high temperature for a long time, and the creep rupture strength is reduced for a long time.
Is preferred. It is desirably 0.08 to 0.20%, and particularly preferably 0.09 to 0.15%.

Mn is added for a deoxidizing agent and the like, and its effect is achieved by adding a small amount, and adding a large amount exceeding 1.5% is not preferable because it lowers the creep rupture strength. Especially 0.03 to 0.20% or 0.3 to 0.7%
Is preferable, and 0.35 to 0.65% is more preferable for the larger one. Higher strength is obtained at 620 ° C. or higher when Mn is smaller. In addition, the higher the Mn content, the better the workability of less than 620 ° C. is selected.

Although Si is also added as a deoxidizing agent, according to a steelmaking technique such as a vacuum C deoxidizing method, Si deoxidizing is unnecessary. Lowering Si has the effect of preventing the formation of harmful δ-ferrite structure and preventing the reduction of toughness due to grain boundary segregation. Therefore, when adding, 0.1.
It is necessary to suppress the content to 25% or less, preferably 0.15% or less, and desirably 0.07% or less, particularly 0.04%.
Less than is preferred.

Ni is a very effective element for increasing the toughness and preventing the formation of δ ferrite.
If it is less than 5%, the effect is not sufficient, and if it exceeds 1.0%, the creep rupture strength is lowered, so that it is not preferable. In particular, it is preferably from 0.3 to 0.7%, more preferably from 0.4 to 0.65%.

Cr is an element indispensable for improving high-temperature strength and high-temperature oxidation resistance, and requires at least 9%.
If it exceeds, a harmful δ ferrite structure is formed and the high-temperature strength and toughness are reduced, so that the content is preferably 8 to 13%. Particularly, it is preferably 10 to 12%, more preferably 10.8 to 11.8%.

The addition of Mo is performed to improve the high-temperature strength. However, when the content of W exceeds 1% as in the steel of the present invention, the addition of Mo of 1.5% or more lowers the toughness and the fatigue strength. Therefore, the content of Mo is preferably 1.5% or less. Especially 620 ° C
For the above, 0.05 to 1.0%, more preferably 0.1 to 0.5%. Further, for temperatures below 620 ° C., 0.75 to 1.75.
5% is preferred.

W suppresses the agglomeration and coarsening of carbides at a high temperature and strengthens the solid solution of the matrix, so that it has an effect of remarkably increasing the high-temperature long-time strength of 620 ° C. or more. 620
1 to 1.5% at ℃, 1.6 to 2.0% at 630 ° C, 6
2.1-2.5% at 40 ° C, 2.6-3.0 at 650 ° C
% At 660 ° C. is preferably 3.1 to 3.5%.
On the other hand, when W exceeds 3.5%, δ ferrite is formed and the toughness is lowered, so that the content is limited to 1 to 3.5%. In particular, 2.4-3.0% is preferable, and 2.5-2.7% is more preferable. W0.1 for steam inlet temperature less than 620 ° C
-0.65%, preferably 0.2-0.45%.

V has the effect of increasing the creep rupture strength by precipitating carbonitrides of V, but if it is less than 0.05%, the effect is insufficient, and if it exceeds 0.35%, δ ferrite is formed and the fatigue strength is increased. Lower. In particular, 0.10 to 0.30% is preferable, and 0.15 to 0.25% is more preferable.

Nb and Ta are elements that are very effective in precipitating NbC and TaC carbides and increasing the high-temperature strength. However, if they are added in a large amount, coarse eutectic NbC or TaC carbides are produced particularly in large steel ingots. , Which causes precipitation of δ-ferrite, which lowers the strength and lowers the fatigue strength, and is therefore preferably not more than 0.20%. If the content of Nb or Ta is less than 0.01%, the effect is insufficient. In particular, 0.02 to 0.15%, preferably 0.04 to 0.10%, alone or in combination.

Co is an important element that distinguishes the present invention from the prior art. In the present invention, the high temperature strength is remarkably improved by the addition of Co, and the toughness is also increased. This is thought to be due to the interaction with W,
Is a characteristic phenomenon in the alloy of the present invention containing 1% or more. In order to realize such an effect of Co, the content of Co in the alloy of the present invention is preferably 0.5% or more. However, even if added excessively, not only a larger effect is not obtained, but also ductility is reduced. 10% or less is preferable. Preferably 5
No addition at less than 93 ° C, 0.2 at less than 600-610 ° C.
Less than 5-2%, 2-3 for 610-620 ° C
%, More than 620 ° C and 3.5-4.5% for 630 ° C
, 630 ° C, 5-6% for 640 ° C, 64%
6.5-7.5% for 650 ° C exceeding 0 ° C, 650 ° C
Above 660 ° C, 8 to 10% is desirable.

N is also an important element that distinguishes the present invention from the prior art. N is effective in improving the creep rupture strength and preventing the formation of the δ ferrite structure, but is effective at 0.0.
If the content is less than 1% or more than 0.1%, the effect is not sufficient. In particular, if the content is more than 0.06% at 620 ° C. or more, the toughness is reduced and the creep rupture strength is also reduced. 0.06% or less is preferable. Especially 0.01 ~
0.03% is more preferable, and 0.015 to 0.025% is more preferable. Further, for a temperature lower than 620 ° C., 0.04 to 0.08% is preferable.

[0078] B is a solid solution in the grain boundary strength effects and M ₂₃ C ₆ carbide is effective to increase the high-temperature strength by the action preventing the aggregation and coarsening of M ₂₃ C ₆ type carbide, added in excess of 0.0005% Is effective, but if it exceeds 0.03%, the weldability and forgeability are impaired, so 0.0005 to 0.03% is preferable.
Desirably 0.001 to 0.01%, or 0.01 to 0.02
% Is preferred.

The addition of Ti and Zr has the effect of increasing toughness, and a sufficient effect can be obtained by adding Ti 0.1% or less and Zr 0.1% or less alone or in combination.

In the present invention, at least the first stage of the rotor shaft and the moving blade and the stationary blade has a C of 0.09 to 0.20% and a Si of 0.15% or less for a steam temperature of 610 to 630 ° C.
Mn 0.05-1.0%, Cr 9.5-12.5%, Ni
0.1 to 1.0%, V 0.05 to 0.30%, N 0.01 to
0.06%, Nb and Ta alone or in combination of 0.01 to
0.20%, Mo 0.05-1.0%, W 2.0-3.5%,
Co 1.0 to 4.5%, B 0.001 to 0.030%, 77
It is preferable to use a steel having a fully tempered martensite structure having Fe of at least%. Also, 63
For a steam temperature of 5 to 660 ° C., the aforementioned Co amount is 5 to
It is preferably 9%, and is preferably constituted by steel having a fully tempered martensite structure having 78% or more of Fe. In particular, the Mn content is set to 0.03 to 0.2 with respect to both temperatures.
% And B content as small as 0.001 to 0.01% provide high strength. In particular, C 0.09 to 0.20
%, Mn 0.1-0.7%, Ni 0.1-1.0%, V0.1.
10 to 0.30%, Nb and Ta alone or in combination of 0.0
1 to 0.20%, N 0.02 to 0.05%, Mo 0.05 to 5%
0.5%, W2-3.5%, 1.0-2.0% Co for 593-620 ° C, 3.5-4.5% Co for 620-630 ° C, B0.001 ~ 0.01% and 6
For 30 to 660 ° C., 5.5 to 9.0% of Co and B0.
It is preferable to set the content to 01 to 0.03%.

Al can be included as a deoxidizing agent,
02% or less is preferable.

The moving blade made of martensitic steel of the present invention can be used in a high-, medium-, or high-to-medium-pressure turbine, preferably in the first, second, or third stage. The stationary blade does not require much strength, but can be used in up to two stages. Although the martensitic steel is used up to the third stage of the rotor blade of the present invention, a Ni-based alloy described later can be similarly used instead.

The high-pressure, medium-pressure, high-medium-pressure rotor materials, rotor blades, stationary blades, and inner casing of the steam turbine of the present invention have a low fatigue strength and toughness when a δ ferrite structure is mixed. Tempered martensite structure is preferred. In order to obtain a tempered martensite structure, the Cr equivalent calculated by the above equation is preferably 4 to 10.5, and more preferably 10 or less, by adjusting the components. If the Cr equivalent is too low, the creep rupture strength decreases, so that a value of 4 or more is preferable. Particularly, the Cr equivalent is from 6.5 to 8 from 5 to 9.5.
Is preferred.

In the rotor of the present invention, an alloy material having a target composition is melted in an electric furnace, carbon is deoxidized in a vacuum, cast into a mold, and forged to produce an electrode rod. This electrode rod is redissolved in electroslag, and forged into a rotor shape and molded. This forging is performed at a temperature of 1150 ° C. or less in order to prevent forging cracks. After annealing the forged steel, 1
Quenching treatment of heating to 000-1100 ° C and quenching, 55
By performing tempering twice in the order of 0 to 650 ° C and 670 to 770 ° C, a steam turbine rotor usable in steam at 620 ° C or higher can be manufactured.

The moving blade, the stationary blade, the inner casing tightening bolt, and the intermediate pressure section first stage diaphragm in the present invention are melted by vacuum melting and cast into a mold under vacuum to produce an ingot. The ingot is hot forged into a predetermined shape at the same temperature as described above, heated at 1050 to 1150 ° C, water-cooled or oil-quenched, then tempered at 700 to 800 ° C, and cut into a blade having a desired shape. Become. Vacuum melting is performed under 10 ^-1 to 10 ^-4 mmHg. In particular, the heat-resistant steel in the present invention can be used in all stages of the blades and nozzles in the high-pressure section and the medium-pressure section, but is particularly necessary in the first step of both.

The high-pressure, medium-pressure or high-medium-pressure integrated steam turbine rotor shaft according to the present invention has a journal portion and a low-temperature region made of 12% Cr-based alloy steel having better weldability than the body portion, and a body portion having a higher temperature than the journal portion. It is preferable to use a high-strength 12% Cr-based alloy steel integrally formed. In particular, in the rotor shaft for an ultra supercritical turbine, the journal portion and the low-temperature portion preferably have no B added or 0.003% or less in the above-described composition, and particularly have a weight ratio of C in the range of 0.05 to 0.20%, preferably 0.06 to 0.14%, Si 0.6% or less, preferably 0.5% or less, Mn 2% or less, Cr 8 to 13%,
Ni 0.2-2.0%, preferably 0.2-1.0%, V
0.05 to 0.35%, Nb and Ta alone or in combination 0.01 to 0.20%, N 0.005 to 0.05%, Mo
1.5% or less, W 0.1 to 4.0%, preferably 1.0 to 4.0%
3.0%, B-free or 0.003% or less and Co10
% Or less, preferably 5% or less, and preferably 0.05 to 0.20%, preferably 0.06 to 0.14%, and 0.6% or less, preferably 0.6% to 0.05%, by weight of the body. 0.15% or less, Mn 1.5% or less, preferably 0.0
3 to 1.5%, Cr 8 to 13%, Ni 0.05 to 1.0%, V
0.05 to 0.35%, Nb and Ta alone or in combination as 0.01 to 0.20%, N 0.005 to 0.1%, preferably 0.005 to 0.06%, Mo 0.05 to 0.5% 1.5%, W
0.1-4.0%, preferably 1.0-3.5%, B0.0
005-0.03% and Co 10% or less, preferably 2%
A martensitic steel containing 10% to 10% is preferable, and is preferably formed of a 12% Cr-based alloy steel having higher high-temperature strength than the journal portion.

The rotor shaft for an ultra-supercritical turbine according to the present invention is characterized in that the journal has higher weldability than the body.
Two or more consumable electrodes of alloy steel whose body is higher in hot strength than the journal part are separately prepared, and the consumable electrode corresponding to the former journal part is first electroslag-melted to obtain a desired length. As soon as the latter, the consumable electrode corresponding to the body portion is electroslag-melted and joined, and then the consumable electrode corresponding to the former journal portion is electroslag-melted, added again and joined together.

Further, in the rotor shaft for an ultra-supercritical pressure turbine of the present invention, the journal portion and the low-temperature region are made of alloy steel (upper and lower ends) having good weldability, and the body (center) is made of an alloy having high high-temperature strength. Prepare an integrated consumable electrode made of steel,
The consumable electrode can also be manufactured by electroslag melting.

(3) The steam turbine rotor shaft made of 12% by weight Cr-based martensitic steel of the present invention has a build-up weld layer of a Cr-Mo low alloy steel having high bearing characteristics on the surface of the base material forming the journal portion. It is preferable to form, preferably 3 to 10 layers of the overlay welding layer is formed using a welding material, and the Cr content of the welding material from the first layer to any of the second to fourth layers is reduced. While decreasing sequentially,
The fourth and subsequent layers are welded using a welding material made of steel having the same amount of Cr, and the welding material Cr used for the first layer is welded.
The amount is about 2 to 6% by weight less than the amount of Cr in the base material,
The Cr content of the fourth and subsequent welding layers is set to 0.5 to 3% by weight (preferably 1 to 2.5% by weight).

In the present invention, overlay welding is preferable for improving the bearing characteristics of the journal portion in terms of the highest safety. Further, a sleeve made of a low alloy steel having a Cr content of 1 to 3% may be formed by shrink fitting or fitting.

In order to increase the number of welding layers and gradually lower the Cr content, three or more layers are preferable, and even more than ten layers are welded. 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. The third and subsequent layers preferably have a tempered martensite structure mainly and have carbides precipitated. In particular, the weight of the composition of the fourth and subsequent welding layers is C
0.01-0.1%, Si 0.3-1%, Mn 0.3-1.5
%, 0.5 to 3% of Cr, and 0.1 to 1.5% of Mo.

(4) The internal casing control valve box, combined reheat valve box, main steam reed pipe, main steam inlet pipe, reheat inlet pipe, high pressure turbine of the high-pressure turbine, medium-pressure turbine and high-medium-pressure turbine of the present invention. Ferritic heat-resistant steel constituting the nozzle box, the first stage diaphragm of the intermediate pressure turbine, the main steam inlet flange of the high pressure turbine, the elbow, and the main steam stop valve is preferable.

For the inner casing material of the heat-resistant ferritic cast steel, particularly, by adjusting the Ni / W ratio to 0.25 to 0.75, the super-supercritical turbine high-pressure and medium-pressure internal casing of 621 ° C. and 250 kgf / cm ² or more, and 625 ° C, required for main steam stop valve and control valve casing
A heat-resistant cast steel casing material having a 10 5 h creep rupture strength of 9 kgf / mm ² or more and a shock absorption energy of 1 kg fm or more at room temperature can be obtained. Then, in order to obtain high high-temperature strength, low-temperature toughness, and high fatigue strength, it is preferable to adjust the Cr equivalent calculated by the above formula to 4 to 10. 625 ° C, 10 ⁵ h when used in steam above 621 ° C
Creep rupture strength of 9 kgf / mm ² or more, room temperature shock absorption energy of 1 kgf-m or more, and 625 ° C., 10 ⁵ h creep rupture strength of 10 k to ensure higher reliability.
gf / mm ² or more, and room temperature impact absorption energy 2 kgf-m or more.

The specific composition is C0.06-0.1 by weight.
16% (preferably 0.09 to 0.14%), N 0.01 to
0.1% (preferably 0.02 to 0.06%), Mn 1%
Or less (preferably 0.4 to 0.7%), no Si added or 0.5% or less (preferably 0.1 to 0.4%), V 0.05
~ 0.35% (preferably 0.15 ~ 0.25%), Nb
0.15% or less (preferably 0.02 to 0.1%), Ni
0.2-1% (preferably 0.4-0.8%), Cr8-
12% (preferably 8 to 10%, more preferably 8.5%
To 9.5%), W1 to 3.5%, Mo1.5% or less (preferably 0.4 to 0.8%), and a martensitic steel comprising the balance Fe.

At less than 1% W, 620-660 ° C.
The effect is not sufficient as a heat-resistant steel used in steel. Also W
Exceeds 4%, the toughness decreases. 1.0 at 620 ° C
1.5%, 1.6-2.0% at 630 ° C, 2.1-2.5% at 640 ° C, 2.6-3.0% at 650 ° C,
At 660 ° C., 3.1 to 3.5% is preferred.

The addition of Ta, Ti and Zr has the 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.

In the heat-resistant cast steel casing material and the like of the present invention, when the δ ferrite content is 5% or less, a decrease in fatigue strength and toughness can be prevented, and a uniform tempered all martensite structure is preferable. In order to obtain a tempered martensite structure, the Cr equivalent calculated by the above equation is 4 to 10, preferably 6 to 9 by adjusting the components.

The addition of B significantly increases the high temperature (620 ° C. or higher) creep rupture strength. If the B content exceeds 0.003%, the weldability deteriorates, so the upper limit is limited to 0.003%. In particular, the upper limit of the B content of the large casing is 0.0028%, preferably 0.0005 to 0.0025%, more preferably 0.001 to 0.002%.

[0099] The casing is required to have a creep rupture strength of 10 kgf / mm ² or more and 10 ⁵ h from the viewpoint of preventing creep destruction, since high stress due to internal pressure acts on high-pressure steam of 620 ° C or more. In addition, at the time of startup, thermal stress acts when the metal temperature is low, so that room temperature impact absorption energy of 1 kgf-m or more is required from the viewpoint of preventing brittle fracture. On the higher temperature side, strengthening can be achieved by containing 10% or less of Co. In particular, 1-2% for 620 ° C or lower, and 2.5-3.5% for 630 ° C.
4% to 5% for 650 ° C, 5.5% to 6.5% for 650 ° C, and 7% to 8% for 660 ° C. At 600 to 620 ° C, it may not be added.

In order to produce a large casing with a small number of defects and an ingot weight of about 50 tons, an advanced manufacturing technique is required. The heat-resistant ferritic cast steel casing material of the present invention can be made sound by melting an alloy material having a target composition in an electric furnace, refining the ladle, and then casting it in a sand mold. By performing sufficient refining and deoxidation before casting, casting defects such as shrinkage cavities can be reduced.

The cast steel in the above-mentioned casing is 1
After annealing heat treatment at 000-1150 ° C, 1000-110
By performing normal heat treatment of heating to 0 ° C. and quenching, and performing tempering twice in the order of 550 to 750 ° C. and 670 to 770 ° C., it can be used in steam at 621 ° C. or higher, and the other is forged steel.

If O exceeds 0.015%, the high-temperature strength and the toughness decrease, so that it is preferably 0.015% or less, particularly preferably 0.010% or less.

(5) The low-pressure steam turbine rotor shaft has a weight of C 0.2 to 0.3%, Si 0.15% or less, Mn 0.2.
5% or less, Ni 3.25 to 4.25%, 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. The rotor shaft has a close relationship with the last stage rotor blade having martensite steel having the specific length described above. 12 above
For 9000 or more, the tensile strength at room temperature is 92 kg / mm ²
Above, those having a FATT of -5 ° C or less, 13800
0 or more, 95 kg / mm ² or more, also having FATT, 144,000 or more, also 103
Those having kg / mm ² or more and also having FATT are 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.

(6) The nozzles other than the last stage of the low-pressure turbine blade and the nozzles are C 0.05-0.2%, Si 0.1-0.1%.
5%, Mn 0.2-1.0%, Cr 10-13%, Mo 0.2%
Preference is given to a fully tempered martensitic steel having a content of between 0.4 and 0.2%.

(7) C-0.2-0.3%, Si-0.3-0.7%, M
Carbon cast steel with n1% or less is preferred.

(8) The main steam stop valve casing and the steam control valve casing are C 0.1-0.2%, Si 0.1-0.4.
%, Mn 0.2 to 1.0%, Cr 8.5 to 10.5%, Mo
0.3 to 1.0%, W 1.0 to 3.0%, V 0.1 to 0.3
%, Nb 0.03 to 0.1%, N 0.03 to 0.08%, B
A fully tempered martensitic steel containing 0.0005 to 0.003% is preferred.

(9) The high pressure turbine, the medium pressure turbine, and the outer casing for the high / medium pressure turbine have C0.10 to 0.20.
%, Si 0.05-0.6%, Mn 0.1-1.0%, Ni
0.1 to 0.5%, Cr 1 to 2.5%, Mo 0.5 to 1.5
%, V0.1-0.35%, preferably Al0.0
25% or less, B 0.0005 to 0.004%, and Ti
Preferably, it is manufactured from cast steel containing at least one of 0.5 to 0.2% and having a fully tempered bainite structure. In particular, C 0.10 to 0.18%, Si 0.20 to 0.60
%, Mn 0.20-0.50%, Ni 0.1-0.5%, C
r 1.0 to 1.5%, Mo 0.9 to 1.2%, V 0.2 to 0.2.
3%, Al 0.001 to 0.005%, Ti 0.045 to 0.1
Cast steels containing 0% and B 0.0005-0.0020% are preferred. More preferably, the Ti / Al ratio is 0.5 to 10
It is.

(10) First-stage blades of high-, medium-, and high-medium-pressure turbines (high-pressure side and medium-pressure side) at a steam temperature of 625 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 includes 0%. After forging, it is subjected to a solution treatment and an aging treatment.

The solution treatment is performed at 1050 to 1200 ° C. for 3 hours.
It is preferable to perform water cooling or air cooling after holding for 0 minutes to 10 hours, or to perform water cooling by pouring the alloy into water at a predetermined temperature or, in the case of a plate, spraying water on the alloy surface at a predetermined temperature. .

The aging treatment is carried out after the solution treatment described above.
It is preferable to carry out by heating and holding at 870 ° C. for 4 to 24 hours.

The Ni-based precipitation strengthened alloy of the present invention has a tensile strength at room temperature of 90 kg / mm ² or more, preferably 100 kg / mm ^2.
mm ² or more, the tensile strength at 732 ° C. is preferably 80 kg / mm ² or more, and the elongation is preferably 10% or more.

[0112]

[Embodiment 1] Table 1 shows the chemical composition (% by weight) of a 12% Cr steel for a long blade material for a steam turbine, and the balance is Fe. Each sample was melted in a vacuum arc of 150 kg, heated to 1150 ° C. and forged to obtain an experimental material. Sample No. 1 was heated at 1000 ° C. for 1 hour, cooled to room temperature by oil quenching, and then heated to 570 ° C. for 2 hours.
After the holding, it was air-cooled to room temperature. No.2 is 1050 ° C for 1 hour
After heating, it is cooled to room temperature by oil quenching, and then 570
C. and kept at room temperature for 2 hours and then air-cooled to room temperature. Sample No.3 ~
No. 11 was heated at 1050 ° C. for 1 hour and then oil-quenched.
Nos. 2 to 14 were heated at 1075 ° C. for 1 hour, cooled to room temperature by oil quenching, then heated to 560 ° C. (low temperature return), held for 2 hours, air-cooled to room temperature (primary tempering), and further 580
C. (returned to high temperature), kept for 2 hours, and air-cooled to room temperature (secondary tempering). All had a fully tempered martensite structure.

In Table 1, Nos. 3 to 14 are materials according to the present invention, and Nos. 1 and 2 are current long wing materials.

Table 2 shows the mechanical properties of these samples at room temperature (20 ° C.). The materials according to the present invention (No.
13 and 14) have a tensile strength (138.5 kgf) required as a long blade material for a steam turbine having a blade length of 45 inches or more.
/ Mm ² or 140 kg / mm ² or more) and low-temperature toughness (20
(V. Notch Charpy impact value of 4 kgf-m / cm ² or more) was confirmed to be sufficiently satisfied. In the table, No. 1 to 11
And the upper stage of Nos. 12 to 14 are the high temperature return material and No. 12
The lower row of ~ 14 is the value of the low temperature return material.

On the other hand, Nos. 1 and 6 have low values of tensile strength and impact value for use in long blades for steam turbines. No. 2 has low tensile strength and toughness. No.
3, 4, 5 and 7 have an impact value of 3.8 kg fm / cm ² or more and a tensile strength of 128.5 kg / mm ² or more, and are satisfactory for a wing length of 43 inches or more. .

[0116]

[Table 1]

[0117]

[Table 2]

FIG. 1 is a diagram showing the relationship between tensile strength and C content. Tensile strength as shown in FIG increased rapidly by the increase in the range of 0.13 to 0.15%, whereas a 130~138kg / mm ² at 0.13% before and after, 0.15% In all of the above, a high strength of 140 kg / mm ² or more can be obtained.

FIG. 2 is a graph showing the relationship between the tensile strength and the amount of Mo. As shown in the figure, the tensile strength is significantly increased by the increase of the Mo amount and the C amount. C content is 0.13-0.1
At 4%, the Mo content is 2.0 to 3.2% and the tensile strength is 132 to
A high value of 138 kg / mm ² was obtained, and the C content was 0.15.
140kg / m at 2.0 ~ 3.3% Mo content at ~ 0.21%
High values of at least m ² , in particular at least 142 kg / mm ^2, are obtained. In the case of Mo of 2.4 to 3.1%, an extremely high Mo of 145 kg / mm ² or more can be obtained. The reason why Nos. 12 to 14 are not shown in the figure is that the quenching temperature is different from the other ones and the Cr content is different.

FIG. 3 is a diagram showing the relationship between the impact value and the tensile strength. In the equation in the figure, the impact value (kg-m / cm ² ) is y,
The tensile strength (kg / mm ² ) is determined as x.

(1) Above the value determined by y = −0.29x + 43.8, the required strength 12 is 43 inches at 3000 rpm or 36 inches at 3600 rpm.
It satisfies 8.5 kg / mm ^{2 and} can further satisfy an impact value of 4 kg-m / cm ² or more. And above this equation, 30
More than 45 inches at 00 rpm and 37 at 3600 rpm.
5 inches and more can be achieved.

(2) If the value of y is greater than or equal to -0.29x + 45, the blade length is 46 inches or more at 3000 rpm and 37.5 inches or more at 3600 rpm. The required tensile strength is 138.5 kg / mm ² or more. 4 kg-m / cm ²
The above can be satisfied. (3) Above the value determined by y = −0.29x + 46.5, the wing length is 47 inches or more at 3000 rpm, and 36
The required tensile strength of 142 kg / 39 inches at 00 rpm
mm ² or more and an impact value of 4 kg-m / cm ² or more.

In the figure, in order to achieve the target blade length on any line, the target mechanical characteristics can be obtained by adjusting the heat treatment temperature.

(Embodiment 2) FIG. 4 shows Nos. 3 to 7 of Embodiment 1.
Wing length 1092 for 3000 rpm using steel described in
5 and 5 are a side view and a front view, respectively, of a long blade (mm) (43 "). 51 is a blade portion to which high-speed steam strikes, 52 is a blade implant portion on a rotor shaft, and 53 is a blade for supporting centrifugal force of the blade. A pin insertion hole for inserting a pin, 54 is an erosion shield provided on the wing leading side for preventing erosion due to water droplets in steam (joint a Co-based alloy stellite plate by welding), 55 is a tie boss and 57 is In this embodiment, the continuous cover 57 is formed by cutting after forging of the whole body, and the continuous cover 57 may be formed mechanically integrally. It can be provided by increasing the hardness of the other wings by quenching.

The 43 ″ long blade was produced by electroslag rewelding and subjected to forging heat and treatment. The forging was performed at a temperature in the range of 850 to 1150 ° C., and the heat treatment was described in Example 1. The metal structure of the long wing was a fully tempered martensite structure, and the wing 51 had the largest thickness at the implanted portion, and gradually became thinner toward the tip.

As shown in FIGS. 4 and 5, the wing implant 52
Is a fork type having eight implants. A pin insertion hole 5 for inserting a pin in a fork shape is provided on the side surface of FIG.
3 are provided in three stages, and concave portions are provided correspondingly. The diameter of the pin insertion hole 53 is the largest on the wing side and is gradually reduced. The inclination of the wing portion 51 in the width direction is substantially parallel to the axial direction of the axle, and the wing implantation portion 52 is gradually inclined at about 75 degrees at the tip of the wing. In this embodiment, the maximum width of the blade implant 52 is about 2.4 times the width of the tip of the blade, and preferably 2.2 to 2.6. Reference numeral 58 denotes an extension width of a tangent line of the wing portion 51 to the vicinity of the wing implantation portion 52, which is an effective width of the wing portion 51 and has about 1.79 times the width of the tip of the wing portion. 1.60-
1.85 times is preferred.

FIG. 6 is a front view showing the positional relationship between the continuous covers 57 of the turbine blades arranged in the steam turbine, as viewed from above the circumferential surface. Wings 51
Are arranged so that they are next to each other. The wings 51 are arranged so as to block the flow of steam.
The continuous cover 57 is formed by the same molding process as the material of the main body.

FIG. 7 shows a wing length of 3000 rpm using martensitic steel described in Nos.
A front view of a long wing of 68 mm (46 inches) and FIG. 8 are side views thereof. The manufacturing method and structure of the long wing of this length are almost the same as those shown in FIGS. 4 and 5, and are the same as those described above, except that it is a fork type having nine wing implants. The wing portion 51 is twisted about 75 degrees in the axial direction with respect to the front view of the wing implantation portion 52 in the same manner as described above. Also,
The maximum width of the wing implant 52 is equivalent to the width of the tip of the wing, and the width of 58 is equivalent. The continuous cover 57 is similarly formed by plastic working integral with the main body material. The pin insertion hole 53 and the erosion shield 54 are the same as described above. Eight corresponding ring-shaped grooves are formed on the rotor shaft corresponding to the fork-shaped implanted portion on the rotor shaft, and wings are implanted along the circumferential direction. Then, a fixing pin is inserted.

The martensitic steel described in No. 12 of Example 1 has a target tensile strength of 138.5 kg / mm ² or more and an impact value of 4 kg-m by slightly increasing the quenching temperature.
/ Cm ² or more can be obtained.

FIG. 9 shows an inverted Christmas tree type wing moving part. FIG. 9 is a plan view and FIG. 10 is a side view thereof. The steam turbine blade shown in this drawing is the same as that of FIGS.
The only difference is the type of the wing implant 52, and the other structures are the same. As shown in the figure, the wing implant 52 has four straight projections on both sides, and the wings are implanted and fixed on the rotor shaft by high-speed rotation by the projections. A groove having the same space as this outer shape is formed in the rotor shaft so as to be implanted along the axial direction of the rotor shaft.

[Embodiment 3] In response to soaring fuel after an oil shock, a pulverized coal direct combustion boiler and steam turbine at a steam temperature of 593 ° C. to 649 ° C. are required in order to improve thermal efficiency by improving steam conditions. Table 3 shows an example of a boiler under such steam conditions.

[0132]

[Table 3]

With the increase in capacity, the furnace for pulverized coal combustion became larger and the furnace width was 31 m and the furnace depth was 16 at 1050 MW class.
m, 1400MW class, furnace width 34m, furnace depth 18m
Becomes

Table 4 shows the main specifications of the steam turbine of 625 ° C. and 1050 MW. In this embodiment, the blade length of the last stage rotor blade in the cross-compound type four-flow exhaust low-pressure turbine is 43 inches, and A is HP-IP and L
3000 r / min with P2 units, B is HP-LP and IP-
Each of the LPs has the same rotation speed of 3000 r / min, and is constituted by the main materials shown in the table in the high temperature part.
The steam temperature of the high pressure section (HP) is 625 ° C, 250kgf / cm
² , and the steam temperature of the medium pressure part (IP) is 625 ° C.
And operated at a pressure of 45 to 65 kgf / cm ² . The low-pressure part (LP) has a steam temperature of 400 ° C
And sent to a condenser at a temperature of 100 ° C. or less and a vacuum of 722 mmHg.

In this embodiment, the distance between the bearings of the high-pressure turbine and the intermediate-pressure turbine connected in tandem and the distance between the bearings of the two low-pressure turbines connected in tandem with respect to the blade length of the last stage rotor blade of the low-pressure turbine are described. Total is about 3
It is 1.5m, the ratio is 28.8, and it is compact.

The distance between the bearings of the high-pressure turbine and the intermediate-pressure turbine connected in tandem with respect to the rated output (MW) of the steam turbine power plant in this embodiment, and the distance between the bearings of the two low-pressure turbines connected in tandem. The ratio of the total distance (mm) of the distances is 30.

[0137]

[Table 4]

FIG. 11 is a cross-sectional view of the high-pressure and intermediate-pressure steam turbines in turbine configuration A in Table 4. The high-pressure steam turbine is provided with a high-pressure axle (high-pressure rotor shaft) 23 in which high-pressure moving blades 16 are implanted in a high-pressure inner casing 18 and a high-pressure outer casing 19 outside thereof. The aforementioned high-temperature and high-pressure steam is obtained by the aforementioned 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 double-flow blade. I will 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 blade is a saddle-type dovetil type, double tinon, and the first stage blade length is about 35 mm. The length between the axles is about 5.8 m, 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 widths of the rotor blade implanted portions of the first stage and the last stage of the rotor shaft are almost equal, and the width of the rotor shaft is stepwise in five stages of the second stage, the third to fifth stages, the sixth stage, and the seventh to eighth stages. The axial width of the second stage implant is 0.71 times as large as that of the last stage.

In the portion of the rotor shaft corresponding to the stationary blade, the diameter of the rotor shaft is smaller than that of the rotor blade implanted portion. The axial width of that part is gradually reduced to the width between the final stage rotor blade and the rotor blade in front of it between the second stage rotor blade and the third stage rotor blade. The width of the latter is 0.86 times smaller than the width of the former. 2nd stage ~
The size is reduced in two stages, up to the sixth stage and the sixth to ninth stages.

In this embodiment, the materials shown in Table 3 to be described later are used for the first stage blade and the first stage nozzle, and the other blades and nozzles do not contain W, Co and B.
% Cr-based steel. The blade length of the rotor blade in this embodiment is 35 to 50 mm in the first stage and becomes longer in each stage from the second stage to the last stage. Particularly, the length from the second stage to the last stage depends on the output of the steam turbine. The length is 65 to 180 mm, the number of stages is 9 to 12, and the length of the wing of each stage is 1.
The length is increased at a rate of 10 to 1.15, and the rate is gradually increased on the downstream side.

The distance between the bearings of the high-pressure turbine in this embodiment is about 5.3 m, and the ratio of the distance between the bearings to the blade length of the last stage rotor blade of the low-pressure turbine is 4.8. The ratio of the distance (mm) between bearings of the high-pressure turbine to the rated output (MW) of the power plant is 5.0.

The medium-pressure steam turbine rotates the generator discharged from the high-pressure steam turbine together with the high-pressure steam turbine by the steam heated by the reheater to 625 ° C. again at a rotation speed of 3000 rpm. Rotated. 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.
7 is provided with a stationary vane. The moving blades 17 have two flows in six stages, and are provided on the left and right substantially symmetrically with respect to the longitudinal direction of the medium pressure axle (medium pressure rotor shaft). The distance between the bearing centers is about 5.8 m, the length of the first stage blade is about 100 mm, and the length of the last stage blade is about 230 mm. The first and second stage dovetails are inverted chestnut type. The diameter of the rotor shaft corresponding to the stationary blade before the last stage rotor blade is about 630 mm, and the ratio of the distance between bearings to the diameter is about 9.2 times.

In the rotor shaft of the medium-pressure steam turbine according to the present embodiment, the axial width of the rotor blade implantation portion is gradually increased in three stages from the first stage to the fourth stage, the fifth stage, and the last stage.
The width at the last stage is about 1.4 times larger than that at the first stage.

The diameter of the rotor shaft of this steam turbine corresponding to the stationary blade portion is small, and the width thereof is stepwise in four stages according to the first stage rotor blade, the second to third stage blades, and the last stage rotor blade side. The width of the latter in the axial direction with respect to the former is reduced to about 0.75 times.

In this embodiment, a 12% Cr steel containing no W, Co and B is used except that the materials shown in Table 5 described later are used for the first stage blade and the nozzle. The length of the blade portion of the moving blade in this embodiment is longer at each stage as it goes 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 nine stages, the length of the wing portion of each stage is longer at a ratio of 1.1 to 1.2 as the length on the downstream side is adjacent to the upstream side.

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.
35 to 0.8, and gradually decreases from the first stage to the last stage.

The intermediate pressure turbine of this embodiment has a bearing distance of about 5.5 m, and the ratio of the intermediate pressure turbine bearing distance to the blade length of the last stage rotor blade of the low pressure turbine is as follows.
The ratio of the distance between bearings (mm) to the rated output (MW) of the power plant is 5.2.

FIG. 12 is a perspective view of the turbine blades implanted in the first stage of the high-pressure turbine, and FIG. 13 is a perspective view of the turbine blades implanted in the second and subsequent stages of the high-pressure turbine and all stages of the medium-pressure turbine. FIG. 12 shows a saddle type implantation type and FIG. 13 shows an inverted Christmas tree type.

FIG. 14 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 last stage rotor blade has a wing length of 4 shown in the second embodiment.
A 3 inch steam turbine blade was used. The nozzle box 45 is of a double flow type.

For the rotor shaft 44, forged steel of super-cleaned bainite steel shown in Table 5 is used. Various characteristics of the steel shown in Table 5 were examined using a 5 kg steel ingot. These steels are heated at 840 ° C for 3 hours after hot forging, and then at 100 ° C /
h, and then tempered by heating at 575 ° C. × 32 h. Table 6 shows the characteristics at room temperature.

[0152]

[Table 5]

[0153]

[Table 6]

Each sample has a fully tempered bainite structure. Tensile strength is 100kg / mm ² or more, F
The ATT has a high strength and a high toughness of -20 ° C. or less, and satisfies the implantation of 46 inches as well as a blade length of 43 inches or more as the last stage blade of the present embodiment. No. 4 having a slightly higher Cr content had a lower strength, and had a Cr content of 2.20.
% Is preferred.

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 distance between the bearing centers for this rotor shaft diameter is about 5.
9.

An 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 57 is formed by cutting after forging of the whole. In addition, the continuous cover 57 can also be integrally formed mechanically.

In the low-pressure turbine according to the present 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 6.8 times larger than the width of the first stage.

Further, the diameter of the portion corresponding to the stationary blade portion is reduced, and the axial width of the portion is gradually increased in the third, fifth, sixth, and seventh stages from the first stage blade side. The width of the last stage is about 2.
5 times larger.

The rotor blades in this embodiment have six stages, and the length of the blade portion increases in each stage from the initial stage of about 3 ″ to the final stage of 43 ″, and from the initial stage to the final stage depending on the output of the steam turbine. The length of the step is 80 ~ 1100mm, 8 steps or 9 steps, and the wing length of each step is 1.2 to 1.8 times as long as the downstream side is adjacent to the upstream side. I have.

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 0.91, and gradually decreases from the first stage to the last stage.

Further, 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.

In this embodiment, two low pressure turbines are connected in tandem, and 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 16.7, and the rated output of the power plant is 1050 (MW). Tandem bound to 2
The ratio of the sum of the distances (mm) between the bearings of the low-pressure turbine at both ends of the table is 17.4. In addition to the present embodiment, 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.10
The same configuration can be applied to a 00MW class large-capacity power plant.

The high-temperature high-pressure steam turbine 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, a low-pressure feedwater heater system, a deaerator, and a booster pump. , Feed water pump,
It is composed of a high pressure feed water heater system. That is, the ultra-high-temperature and high-pressure steam generated in the boiler enters the high-pressure turbine to generate power, is reheated again in the boiler, and enters the medium-pressure turbine to generate power. This medium-pressure turbine exhaust steam enters the low-pressure turbine and generates power,
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 water supply 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 temperature of the feedwater 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.

The average diameter of the last stage rotor blade of the low pressure turbine in this embodiment is 3000 rpm, 3570 mm with 43 ″ blades.
And 3600 rpm, 2975 mm with 36 "wings, 3645 mm with 46" wings for the former and 30 with 38 "wings for the latter
It was 40 mm. The average diameter is the diameter between the centers of the blade lengths of the bucket.

In place of the present embodiment, one low-pressure turbine is connected to each of the high-pressure turbine and the medium-pressure turbine in tandem, and a single generator is connected to each of them to generate power. A plant can be similarly configured. In the generator of the present embodiment having an output of 1050 MW, a shaft having a higher strength is used as the generator shaft. In particular, C 0.15 to 0.30
%, Si 0.1 to 0.3%, Mn 0.5% or less, Ni 3.2%
5 to 4.5%, Cr 2.05 to 3.0%, Mo 0.25 to 0.6
0% has a fully tempered bainite structure containing V0.05～0.20% at room temperature tensile strength of 93kgf / mm ² or more, particularly 100 kgf / mm ² or more, 50% FATT is 0 ℃ or less,
In particular, it is preferable that the temperature be -20 ° C or lower, and 21.2KG
And the total amount of P, S, Sn, Sb and As as impurities is 0.02.
It is preferable that the Ni / Cr ratio be 5% or less and the Ni / Cr ratio be 2.0 or less.

The high-pressure turbine shaft has a structure in which nine stages of blades are planted around the first stage blade planting portion on the multi-stage side. The medium-pressure turbine shaft has a multi-stage blade provided on the left and right with approximately six stages of symmetrical blade installation portions, and substantially centered on the center. Although the rotor shaft for the low-pressure turbine is not shown, a center hole is provided in any of the rotor shafts of the high-pressure, medium-pressure, and low-pressure turbines, and through this center hole, the presence or absence of a defect is determined by ultrasonic inspection, visual inspection, and fluorescence inspection. Is inspected. Further, the inspection can be performed by ultrasonic inspection from the outer surface, and the center hole may not be provided.

The average diameter of the last stage rotor blade of the low pressure turbine in this embodiment is 3000 rpm, 2855 with 43 ″ blade.
mm, 3600 rpm, 2380 mm with 36 "wings, plus 300
0rpm, 46 "wing with 2930mm, 3600rpm, 38"
It was 2440 mm with wings.

Table 7 shows the chemical compositions (% by weight) used for the main parts of the high-pressure turbine, medium-pressure turbine and low-pressure turbine according to the present 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.

For the rotor shafts of the high-pressure turbine and the intermediate-pressure turbine, 30 tons of the heat-resistant cast steel shown in Table 7 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 carried out at 1150 to prevent forging cracks.
Performed at a temperature of less than or equal to ° C. After annealing this forged steel,
Heating to 1050 ° C., water spray cooling, quenching, and tempering twice at 570 ° C. and 690 ° C.
This was obtained by cutting into the shape shown in FIG. In the present embodiment, the upper side of the electroslag steel ingot is the first stage blade side, and the lower side is the last stage side. Each rotor shaft has a center hole, and the center hole can be eliminated by reducing impurities.

The high-pressure part and the medium-pressure part of the blade and the nozzle were prepared by melting the heat-resistant steel shown in Table 7 in a vacuum arc melting furnace to form a blade and a 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.

The inner casing of the high pressure section and the intermediate pressure section, the main steam stop valve casing and the steam control valve casing are shown in Table 7.
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-heat treatment was 400 ° C. × 30 minutes. No weld crack was observed in the material of the present invention, and the weldability was good.

[0174]

[Table 7]

Table 8 shows the mechanical properties and heat treatment conditions obtained by cutting and examining the main members of the high temperature steam turbine made of ferritic steel described above.

As a result of examining the center part of the rotor shaft, the characteristics (62
5 ° C., 10 ⁵ h strength ≧ 10 kgf / mm ² , 20 ° C. shock absorption energy ≧ 1.5 kgf-m). This demonstrated that a steam turbine rotor usable in steam at 620 ° C. or higher can be manufactured. Also, as a result of investigating the characteristics of this blade, the characteristics (625 ° C., 10
It was confirmed that ⁵ h strength ≧ 15 kgf / mm ² ) was sufficiently satisfied. This demonstrated that a steam turbine blade usable in steam at 620 ° C. or higher can be manufactured.

Furthermore, as a result of investigating the characteristics of the casing, it was found that the characteristics required for the high-pressure and intermediate-pressure turbine casings (625 ° C., 10 ⁵ h strength ≧ 10 kgf / mm ² , 20 ° C. shock absorption energy ≧ 1 kgfm) were sufficient. Satisfaction and weldability were confirmed. Thereby, 620 ° C
It was proved that a steam turbine casing usable in the above steam could be manufactured.

[0178]

[Table 8]

In the present embodiment, a Cr-Mo low alloy steel was build-up welded on the journal portion of the rotor shaft to improve the bearing characteristics. The overlay welding is as follows.

A coated arc welding rod (diameter: 4.0φ) was used as a test welding rod. Table 9 shows the chemical composition (% by weight) of the deposited metal obtained by welding using the welding rod. The composition of the deposited metal is almost the same as the composition of the welding material.

The welding conditions were as follows: welding current 170 A, voltage 24
V, speed 26 cm / min.

[0182]

[Table 9]

As shown in Table 10, the overlay welding was carried out on the surface of the base metal to be tested by combining the welding rods used for each layer and eight layers. The thickness of each layer was 3-4 mm, the total thickness was about 28 mm, and the surface was ground about 5 mm.

The welding conditions were preheating, between passes, a stress relief annealing (SR) start temperature of 250 to 350 ° C., and SR processing conditions of 630 ° C. × 36 hours.

[0185]

[Table 10]

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 °, but no crack was found in the welded portion.

Further, a bearing sliding test by rotation in the present invention was performed.
It was also excellent in oxidation resistance.

Instead of this embodiment, a tandem type power plant having 3000 revolutions by combining a high-pressure steam turbine, a medium-pressure steam turbine and one or two low-pressure steam turbines in tandem, and turbine configuration B in Table 4 The high-pressure turbine, the intermediate-pressure turbine and the low-pressure turbine of the present embodiment can be similarly combined and configured.

In each of the above-mentioned examples, the blade implant portion of the last stage rotor blade of the low-pressure turbine was an inverted Christmas tree type.

Example 4 Table 11 shows that the steam temperature was 600 ° C.
This is the main specification of the rated output 700 MW steam turbine. In this embodiment, the final stage blade length in a tandem compound double flow type, low pressure turbine is 46 inches, and HP
(High pressure) / IP (medium pressure) integrated type and one LP (C) or two LPs (D) have a rotation speed of 3000 rpm, and are composed of the main materials shown in the table in the high temperature section. High pressure section
The steam temperature of (HP) is 600 ° C. and a pressure of 250 kgf / cm ² , and the steam temperature of the medium pressure part (IP) is heated to 600 ° C. by a reheater and operated at a pressure of 45 to 65 kgf / cm ^2. You. The low pressure section (LP) enters at a steam temperature of 400 ° C,
It is sent to the condenser at a temperature of 100 ° C. or less and a vacuum of 722 mmHg.

In this embodiment, the steam turbine power plant including the high-medium pressure integrated turbine in which the high-pressure turbine and the medium-pressure turbine are integrated and two low-pressure turbines has a bearing distance of about 22.7 m. The ratio of the distance between the bearings of the high and medium pressure integrated turbine and the distance between the bearings of the two low pressure turbines connected in tandem to the blade length (1168 mm) of the last stage rotor blade of the turbine is 19.4;
In addition, 1M at the rated output of 1050MW of the power plant
The ratio of the total distance (mm) of the distance between the bearings of the high-medium pressure integrated turbine and the distance between the bearings of the two low-pressure turbines connected in tandem to W is 21.6.

Further, in this embodiment, the steam turbine power plant including the high / medium pressure integrated turbine in which the high pressure turbine and the medium pressure turbine are integrated and one low pressure turbine is provided.
The distance between the bearings is about 14.7 m, and the ratio of the total distance between the bearings of the high and medium pressure integrated turbine and the distance between the bearings of one low pressure turbine to the blade length (1168 mm) of the last stage rotor blade of the low pressure turbine is 12 .6. The ratio of the sum of the distance between the bearings of the high and medium pressure integrated turbine and the distance between the bearings of one low pressure turbine to 1 MW at a rated output of 700 MW of the power plant is 21.0.

[0193]

[Table 11]

FIG. 15 is a sectional view of a high-pressure / intermediate-pressure integrated steam turbine, and FIG. 16 is a sectional view of its rotor shaft. The high-pressure side steam turbine is provided with a high-to-medium pressure axle (high-pressure rotor shaft) 33 in which high-pressure moving blades 16 are implanted in a high-pressure inner casing 18 and a high-pressure outer casing 19 outside thereof. The aforementioned high-temperature and high-pressure steam is obtained by the aforementioned boiler, passes through a main steam pipe, and forms a flange and an elbow 2 that constitute a main steam inlet.
5 through the main steam inlet 28 and 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 in the figure and six stages on the medium pressure side (about half the right side in the figure).
Steps are provided. 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, and the diameter of the smallest part corresponding to the stationary blade part is about 74.
0 mm and the ratio of length to diameter is about 9.0.

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

On the high pressure side, the blades and nozzles were made of 12% Cr steel shown in Table 7 described later. The blade length of the rotor blade in this embodiment is 3 in the first stage.
5 to 50 mm, the length of each stage increases from the second stage to the final stage. In particular, the length from the second stage to the final stage is in the range of 50 to 150 mm depending on the output of the steam turbine,
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 1.3 as the length that the downstream side is adjacent to the upstream side.
The ratio is longer within the range of 5 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.

In the rotor shaft of the medium-pressure steam turbine, the axial width of the root portion of the rotor blade implantation is the largest at the first stage, smaller at the second stage, smaller at the third to fifth stages less than the second stage, and the same. The width of the last stage is between the third to fifth stages and the second stage, and is 0.48 to 0.64 times that of the first stage. The first stage is the second stage 1.
It is 1 to 1.5 times.

On the medium pressure side, the blade and the nozzle are made of 12% Cr-based steel shown in Table 7 above. The length of the blade portion of the moving blade in this embodiment is longer at each stage as it goes from the first stage to the last stage, and the length from the first stage to the last stage is 90 to 350 mm, and the number of stages is 6 to 6 depending on the output of the steam turbine. There are nine stages, and the length of the wing of each stage is 1.10 to 1.25, which is longer than the length adjacent to the upstream side on the downstream side.

The implanted portion of the moving blade has a diameter larger than that of the portion 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 in tandem in this embodiment has a distance between bearings of about 5.7 m and the blade length of the last stage blade of the low-pressure turbine ( The ratio of the bearing distance (mm) to 16.8 at the rated output of 1050 MW of the power plant is 6.4.

Also in this embodiment, the bearing portion 27 is provided with a build-up welding layer of low alloy steel as in the third embodiment. Further, although the reference numerals are omitted in the rotor shaft, the rotor blade studs 45 are provided in all stages on the high pressure side and the medium pressure side in the same manner as in the third embodiment.

FIG. 17 is a sectional view of the low-pressure turbine and FIG.
Is a sectional view of the rotor shaft. There are one low pressure turbine or two in tandem, both of which are coupled in tandem at high and medium pressure. 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. Example 2 The blade length of the last stage is 46 inches.
The steam turbine blades made of 12% Cr steel described in Nos. 9 to 14 shown in FIG. This shape is shown in FIGS. 7 and 8 of the second embodiment, and the same applies to the twist angle at the blade tip. As the rotor shaft 43, forged steel having a fully tempered bainite structure of a super clean material made of No. 5 in Table 5 of Example 3 is used. 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. The inner and outer casing members are made of cast steel of 0.25% C having the above-mentioned composition. 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 implantation 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.

Also in this embodiment, the rotor shaft is provided with a rotor blade stud portion 45, and, as in the third embodiment, the last stage is provided with a fork-type or inverted Christmas tree-type blade implant portion. Example 3 for other blades
An implantation portion is provided in the same manner as described above.

In the low-pressure turbine, the axial width of the root portion of the blade implant is the smallest at the first stage, and at the downstream side, two or three stages are equal, four and five stages are equal, and the width gradually increases in 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 rotor blades increases in each stage from the initial stage of 4 ″ to the final stage of 46 ″. Depending on the output of the steam turbine, the length of the blade from the initial stage to the final stage is 100 to 100 μm. Within 1270mm, up to 8 steps,
The wing length of each stage is longer within a range of 1.2 to 1.9 times as long as the downstream side is adjacent to the upstream side.

The root portion of the rotor blade has a larger diameter than the portion corresponding to the stationary blade, and has a divergent width. The greater the blade length of the rotor blade, the greater the implantation width. 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 final stage rotor blade in this embodiment is 3000 rpm, 2590 mm with 43 ″ blade, 360 mm
0rpm, 36 "wings 2160mm, 3000rpm, 46"
2665mm with wings, 3600rpm, 2220mm with 38 "wings
And

The erosion shield (stellite alloy) 54 in this embodiment was joined by electron beam welding or TIG welding 56. The erosion shield 54 is welded over the entire length of the erosion shield at two locations, one on the surface directly exposed to the wet steam and the other on the reverse side. The front side is wider than the back side, and the upper and lower ends are also welded.

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 about 60 ° C.
The same configuration can be applied to a MW class large-capacity power plant.

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, and 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, in the boiler, the water supply 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 the power generation of the rated output of 1050 MW class in this embodiment, a higher strength generator shaft is used. In particular, C 0.15 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%, Mo 0.25 to 0.60%,
It has a fully tempered bainite structure containing 0.05 to 0.20% V and has a room temperature tensile strength of 93 kgf / mm ² or more,
0 kgf / mm ² or more, 50% FATT is 0 ° C. or less, especially −
Preferably, the temperature is 20 ° C. or less, the magnetization 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 Those having a value of 2.0 or less are preferable.

Table 7 above shows the chemical compositions (% by weight) used for the main parts of the high-medium pressure turbine and the low pressure turbine of this embodiment. In the present embodiment, the rotor shaft integrated with the high-pressure side and the medium-pressure side is made of the one shown in Table 7 except that a martensite steel of No. 7 of Example 5 described later is used. Thermal expansion coefficient of 12 × 10 ^-6 /
° C, there was no problem due to the difference in the coefficient of thermal expansion.

For a steam temperature of 620 ° C. or higher for the rotor shaft of the high-medium pressure turbine, the materials shown in Table 12 of Example 3 or Example 5 described later can be used. In this example, No. 1 in Table 12 is suitable for 625 ° C., and 30 tons of heat-resistant cast steel is melted in an electric furnace, carbon is deoxidized in vacuum, cast into a mold, forged and stretched to produce an electrode rod, 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 the rotor shape (diameter 1450 mm, length 5000)
mm). The forging was performed at a temperature of 1150 ° C. or less in order to prevent forging cracks. Further, after the annealing heat treatment, the forged steel was heated to 1050 ° C., subjected to water spray cooling quenching, and tempered twice at 570 ° C. and 690 ° C.
This was obtained by cutting into the shape shown in FIG. The materials and manufacturing conditions of the other parts are the same as in the third embodiment. Further, a build-up welded layer of Cr-Mo low alloy steel on the bearing 27 was formed in the same manner as in Example 3.

The low pressure turbine for a steam turbine power plant having two low pressure turbines connected in tandem in this embodiment has a total bearing distance of 16 m, and the blade length of the last stage rotor blade of the low pressure turbine (1168 mm). ) And the sum of the bearing distances of the two low-pressure turbines coupled in tandem to 1 MW at a rated output of 1050 MW for the power plant is 13.7. The ratio of the distance (mm) is 15.2.

In the present embodiment, the low-pressure turbine for a steam turbine power plant having a high-medium pressure integrated turbine in which a high-pressure turbine and a medium-pressure turbine are integrated and one low-pressure turbine has a bearing distance of 6 m. Of the last stage rotor blade to the blade length (1168 mm) is 6.8, and the distance between the bearings of one low-pressure turbine per 1 MW at the rated output of the power plant of 700 MW is the distance between the bearings of one low-pressure turbine. (mm) is 11.4.

The high- and medium-pressure integrated rotor shaft of this embodiment or the rotor shafts of Examples 5 to 9 to be described later have a center hole.
0% or less, S 0.005% or less, As 0.005% or less,
By adjusting the content of Sn to 0.005% or less and the content of Sb to 0.003% or less, the center hole can be eliminated by high purification in any of the embodiments.

Example 5 Instead of the rotor shafts of Examples 3 and 4, an alloy having a suitable composition corresponding to the steam temperature shown in Table 12 was cast into an ingot of 10 kg by vacuum melting and forged into a 30 mm square. Things. In the case of a large steam turbine rotor shaft, the central
After holding at 050 ° C for 5 hours, the cooling rate at the center is 100 ° C
/ H cooling quenching, primary tempering at 570 ° C. × 20 hours, secondary tempering at 690 ° C. × 20 hours, and quenching at 1100 ° C. × 1 hour and tempering at 750 ° C. × 1 hour for blades at 625 ° C. The creep rupture test was performed at 30 kgf / mm ² . The results are shown in Table 12.

The alloys of the present invention No. 1 to No. 7 in Table 12 are as follows:
It is preferable to apply to steam conditions of 620 ° C. or higher, and it is understood that the creep rupture life is long. Although the creep rupture time improves as the amount of Co increases, the increase in the amount of Co tends to cause heat embrittlement when heated at 600 to 660 ° C.
1 to 3.5% for 630 to 630 ° C, 630 to 660 ° C
Is preferably 4 to 8%. B shows excellent strength when 0.03% or less. At 600 to 630 ° C, the amount of B is 0.0.
0.01 to 0.01% and the Co content is 1 to 3.5%, 630 to
On the higher temperature side of 660 ° C., high strength can be obtained by increasing the B content to 0.01 to 0.03% and the Co content to 4 to 8.5%.

It was clarified that N was strengthened when the temperature exceeded 600 ° C. in the examples of the present invention, and that the N was higher in strength than those with a large amount of N. The N content is 0.01 to 0.1.
04% is preferred. Since N is hardly contained in the vacuum melting, it is added by the master alloy.
For further strengthening, the Mn content is preferably set to 0.03 to 0.20%.

[0222]

[Table 12]

Similarly, Table 13 shows the chemical composition (% by weight) of the rotor shaft material suitable for 593 to 610 ° C. Heat treatment is performed at 1100 ° C. × 2 h → 100 ° C./h, then 5
65 ℃ × 15h → cooling at 20 ℃ / h, 665 ℃ × 45h
→ Cooled at 20 ° C / h. All the heat treatments were performed while rotating around a rotation axis.

Table 14 shows the mechanical properties of the rotor shaft material. Impact value is V notch Charpy value, FA
TT is the 50% fracture surface transition temperature.

[0225]

[Table 13]

[0226]

[Table 14]

The creep rupture strength of the material of the present invention was 60%.
0 ° C, 10 ⁵ h Creep rupture strength is 11 kgf / mm ² ,
Strength required for high-efficiency turbine materials (10 kgf / mm ² )
The above and toughness also show high values of 1 kgfm or more.

[0228] No.9 but are those Al exceeds 0.015%, 10 ⁵ h creep rupture strength of 11 kgf / mm ²
Below, the strength is slightly reduced. When W was increased by about 1.0%, δ ferrite was precipitated, and both strength and toughness were low, and it was also confirmed that the object of the invention was not achieved. W is 0.1
A high strength can be obtained at 0.65%.

The effect of W on FATT is 0.1 to 0.1%.
In the range of 0.65%, FATT is low and high toughness is obtained. Especially 0.2
A low FATT is obtained at ~ 0.5%.

The martensitic steel of this example has a remarkably high high-temperature creep rupture strength at around 600 ° C., and sufficiently satisfies the strength required for a rotor shaft for an ultra-high-temperature and high-pressure steam turbine. It is also suitable as a high-efficiency turbine blade at around 600 ° C.

Example 6 Table 15 shows the chemical compositions (% by weight) of the internal casing material for high, medium and high pressure turbines of the present invention in Examples 3 and 4. Assuming the thick portion of the large casing, the sample was melted in a high-frequency induction melting furnace to melt 200 kg and cast into a sand mold having a maximum thickness of 200 mm, a width of 380 mm and a height of 440 mm to produce an ingot. The sample is
1050 ° C. × 8 h After furnace cooling annealing, normalizing (1050 ° C. × 8 h) assuming a thick part of a large steam turbine casing
→ air cooling, tempering (710 ° C × 7h → air cooling, 710 ° C ×
7h → air cooling twice).

The weldability was evaluated according to JIS Z3158. Pre-heat, inter-pass and post-heat onset temperature is 150 ° C
The post heat treatment was performed at 400 ° C. for 30 minutes.

[0233]

[Table 15]

Table 16 shows tensile properties at room temperature, V-notch Charpy impact absorption energy at 20 ° C., 650 ° C., 1
The results of the 0 ⁵ h creep rupture strength and weld crack tests are shown.

The creep rupture strength and impact absorption energy of the material of the present invention to which appropriate amounts of B, Mo and W are added are determined by the characteristics (625 ° C., 1
0 ⁵ h strength ≧ 8 kgf / mm ² , shock absorption energy at 20 ° C. ≧
1 kgf-m). In particular, it shows a high value of 9 kgf / mm ² or more. In addition, no weld cracking was observed in the material of the present invention, and the weldability was good. As a result of examining the relationship between the B content and weld cracking, when the B content exceeded 0.0035%, weld cracks occurred. No. 1 was a little worried about cracking. Looking at the effect of Mo on the mechanical properties, those with a high Mo content of 1.18%, although having high creep rupture strength, had low impact values and could not satisfy the required toughness. On the other hand, the alloy with Mo 0.11% had high toughness but low creep rupture strength, and could not satisfy the required strength.

As a result of examining the effect of W on the mechanical properties, it was found that the creep rupture strength was significantly increased when the W amount was 1.1% or more, whereas the impact absorption energy at room temperature was increased when the W amount was 2% or more. Becomes lower. In particular, the Ni / W ratio is set to 0.2.
By adjusting the 5-0.75, temperature 621 ° C., are required to a pressure 250 kgf / cm ² or more high pressure and intermediate pressure internal casing of the high-temperature and high-pressure turbine and a main steam stop valve and governor valve casing, 625 ° C., 10 ⁵ h creep rupture strength 9 kgf / mm ² or more, shock absorption energy at room temperature 1 kgfm
The above heat-resistant cast steel casing material is obtained. Particularly, by adjusting the W amount to 1.2 to 2% and the Ni / W ratio to 0.25 to 0.75, the creep rupture strength at 625 ° C. and 10 ⁵ h
0 kgf / mm ² or more, impact absorption energy at room temperature 2 kgf-m
The above excellent heat-resistant cast steel casing material can be obtained.

[0237]

[Table 16]

The amount of W is remarkably strengthened by setting it to 1.0% or more, and especially 8.0 kg or more at 1.5% or more.
A value of f / mm ² or more is obtained. No. 7 of the present invention is 640
The required strength was sufficiently satisfied at a temperature of not more than ℃.

One ton of an alloy raw material having the target composition of the heat-resistant cast steel of the present invention was melted in an electric furnace, and after ladle refining, it was cast into a sand mold to obtain an internal casing of a high-to-medium-pressure portion described in Example 3. This casing is subjected to an annealing heat treatment at 1050 ° C. × 8 h for furnace cooling, then a normal heat treatment at 1050 ° C. × 8 h for blast cooling, and 730 ° C.
Tempering was performed twice in a furnace for 8 hours. As a result of cutting investigation of this prototype casing having a fully tempered martensite structure, the characteristics (625 ° C, 10 ⁵ h strength ≧ 9 kgf / mm required for a high-pressure, high-pressure turbine casing at 250 atm, 625 ° C) were obtained.
^2. It was confirmed that 20 ° C impact absorption energy ≧ 1 kgf-m) was sufficiently satisfied and that welding was possible.

[Embodiment 7] In this embodiment, the steam temperature of the high-pressure steam turbine and the medium-pressure steam turbine at 625 ° C of the third embodiment, or the steam temperature of the high-medium-pressure steam turbine at 600 ° C and 625 ° C of the fourth embodiment is particularly used. 649 ° C., and the structure and size can be obtained with almost the same design as in the third or fourth embodiment. Here, what is different from the third or fourth embodiment is the rotor shaft, the first-stage moving blade, the first-stage stationary blade, and the inner casing of the high-pressure, medium-pressure or high-medium-pressure integrated steam turbine which is in direct contact with this temperature. Among these materials excluding the inner casing, the B content of the materials shown in Table 8 was set at 0.3.
The required strength is increased by increasing the W content of Example 2 to 2 to 3% and adding 3% of Co as the inner casing material, by increasing the Co content to 0.01 to 0.03% and the Co content to 5 to 7%. Satisfied, there is a great advantage that conventional designs can be used.
That is, in the present embodiment, the conventional design concept can be used as it is in that all the structural materials exposed to high temperatures are made of ferritic steel. Since the steam inlet temperature of the moving blade and the stationary blade of the second stage is about 610 ° C., it is preferable to use the material used in the first stage of the third embodiment.

Furthermore, the steam temperature of the low-pressure steam turbine is about 405 ° C., which is slightly higher than about 380 ° C. in the third or fourth embodiment. However, the rotor shaft itself has a sufficiently high strength because the material of the third embodiment has a sufficiently high strength. Also, a super clean material is used.

Further, in contrast to the cross-compound type in this embodiment, a tandem compound type can be used at a rotation speed of 3600 rpm.

Table 17 shows the chemical composition of the Ni-based precipitation strengthening type alloy used for each of the moving blades of up to three stages in the high pressure turbine having a steam temperature of 640 ° C. or higher and in the first stage in the medium pressure turbine. These alloys are hot-forged after manufacturing an ingot by vacuum arc remelting, and then heat-treated at 1070 to 1200 ° C. for 1 to 8 hours and then air-cooled according to the alloy composition to obtain an ingot.
It has been subjected to an aging treatment of heating at 0 to 870 ° C for 4 to 24 hours.

In the high-pressure turbine, the high-strength martensitic steel according to the present invention was used in the fourth and fifth stages, and in the second and third stages of the medium-pressure turbine. Another example is steam temperature 610-6
The above-described Ni-based alloy can be used in the first stage of the high-pressure turbine and the intermediate-pressure turbine at 38 ° C., and the high-strength martensitic steel of the present invention can be used in the second and third stages of the high-pressure turbine and the second stage of the medium-pressure turbine. .

This embodiment is applicable to Embodiments 5 and 6.

[0246]

[Table 17]

[Embodiment 8] The high-pressure turbine, the medium-pressure turbine, and the rotor shaft for the high- and medium-pressure turbine in the power plants of Examples 3 and 4 were manufactured by changing the amount of B for the body and the bearing, respectively. Other configurations are exactly the same as those of the third and fourth embodiments. 30 tons of heat-resistant cast steel according to the body and bearing described in Table 18 (% by weight) were melted in an electric furnace, carbon deoxidized, cast into a mold, and forged to produce an electrode rod. First, the bearing portion is electroslag-dissolved using an electrode rod, then the body portion is electro-dissolved immediately, and the bearing portion is further electro-slag-dissolved thereon, and forged into a rotor shape (diameter 1050 mm, length 3700 mm). And molded. The forging was performed at a temperature of 1150 ° C. or less in order to prevent forging cracks. After annealing the forged steel, 10%
Heating to 50 ° C, water spray cooling, quenching, 570 ° C and 6
It was obtained by performing tempering twice at 90 ° C. and cutting it into the shape shown in FIGS. 19 and 20. The body and the bearing are joined at a position shown by a dotted line. As shown in FIG. 19, the rotor shaft for the high-pressure steam turbine is between the last stage on the downstream side of the blade and immediately before the blade, and the rotor shaft for the medium-pressure steam turbine shown in FIG. They are joined. In the present embodiment, the upper side of the electroslag steel ingot is set to the first stage side of the body, and the lower side is set to the last stage side.

Also in the present embodiment, the bearing portion 27 is provided with low alloy steel, and furthermore, the rotor blade studs 45 are formed in eight steps in a ring shape. Formed.

The high-pressure and medium-pressure blades and nozzles were prepared by melting the heat-resistant steel shown in Table 18 in a vacuum arc melting furnace to form blade and nozzle materials (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 is heated to 1050 ° C., subjected to oil quenching, tempered at 690 ° C., and then cut into a predetermined shape. The internal casing, the main steam stop valve casing, and the steam control valve casing of the high-pressure part and the medium-pressure part were prepared by melting the heat-resistant cast steel shown in Table 17 in an electric furnace, refining the ladle, and pouring it into a sand mold. 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 was performed according to JIS Z3158. Preheating,
Inter-pass and post heat onset temperature is 200 ° C, post heat treatment is 40 ° C.
It was 0 ° C. × 30 minutes. No weld crack was observed in the material of the present invention, and the weldability was good.

[0250]

[Table 18]

Table 19 shows the mechanical properties of the body of the rotor shaft described above. The heat treatment was carried out by water spray cooling after heating and holding at 1050 ° C. × 15 h, and then cooling at 570 ° C. × 20 h and heating at 690 ° C. × 20 h.

As a result of examining the center of the rotor shaft, it was found that the characteristics (62
5 ° C., 10 ⁵ h strength ≧ 13 kgf / mm ² , and 20 ° C. shock absorption energy ≧ 1.5 kgf-m). This demonstrated that a steam turbine rotor usable in steam at 620 ° C. or higher can be manufactured. Also, as a result of investigating the characteristics of this blade, the characteristics (625 ° C., 10
It was confirmed that ⁵ h strength ≧ 15 kgf / mm ² ) was sufficiently satisfied. This demonstrated that a steam turbine blade usable in steam at 620 ° C. or higher can be manufactured.

Further, as a result of investigating the characteristics of this casing, it was found that the characteristics (625 ° C., 10 ⁵ h strength ≧ 10 kgf / mm ² , 20 ° C. shock absorption energy ≧ 1 kgfm) required for the high-pressure and intermediate-pressure turbine casings were sufficiently obtained. Satisfaction and weldability were confirmed. Thereby, 620 ° C
It was proved that a steam turbine casing usable in the above steam could be manufactured.

[0254]

[Table 19]

In this embodiment, similarly to the third and fourth embodiments, the Cr-Mo low alloy steel was build-up welded on the journal portion of the rotor shaft to improve the bearing characteristics.

In order to confirm the performance of the welded portion, the plate material was similarly overlaid and subjected to a side bending test at 160 °, but no crack was found in any of the welded portions. In each case, the sixth and subsequent layers have the compositions shown in the respective tables.

Further, a bearing sliding test by rotation in the present invention was performed.
It was also excellent in oxidation resistance.

In place of the present embodiment, a high-pressure steam turbine, a medium-pressure steam turbine and two low-pressure steam turbines may be connected in tandem to form a tandem-type power plant having 3,600 revolutions.

This embodiment can be similarly applied to Embodiments 5 to 7.

[Embodiment 9] In this embodiment, the last stage blade length in a tandem compound double flow type, low pressure turbine similar to that of Embodiment 4 is 46 inches, and HP (high pressure) is used.
・ IP (medium pressure) integrated type and 3000r with one or two LPs
It has a rotation speed of pm and is made of the main material as in the fourth embodiment. The steam temperature of the high pressure section (HP) on the left is 60
0 ° C, pressure of 250 kg / cm ² , medium pressure part (I
The vapor temperature of P) is heated to 600 ° C. by a reheater,
It is operated at a pressure of 170-180 kg / cm ² . The low pressure part (LP) has a steam temperature of 450 ° C,
It is sent to the condenser at a vacuum of 722 mmHg.

FIG. 20 is a sectional view of the rotor shaft of the high-pressure / intermediate-pressure integrated steam turbine used in this embodiment.
As shown in the figure, the steam enters both the high-pressure part and the medium-pressure part from the center of the rotor shaft and has a configuration in which the steam flows to the bearing part side, and therefore the temperature is low on the bearing part side. The rotor shaft in this embodiment is manufactured by the electroslag remelting method by changing the alloy composition of the bearing portion and the body portion in the same manner as in the eighth embodiment, and in each case, the composition is changed before the final stage. is there. The structure of FIG.
It is exactly the same as 6. The composition of the body in this example was No. 5 in Table 12, and only the B content of the bearing was 0.003%.
And the other components are the same. The heat treatment after forging is the same as described above.

In this embodiment, as in the case of the third or fourth embodiment, a cladding welding layer of Cr-Mo low alloy steel is formed on the bearing portion.

The embodiments 2, 4 and 5 can be applied to the present embodiment, and can be applied to the steam temperature of the embodiment 6 in the same manner.

[0264]

According to the present invention, by using high-strength and high-toughness martensitic steel for a low-pressure turbine of a steam turbine having a steam temperature of 593 to 660 ° C., the last stage rotor blade can be made longer. Therefore, high-efficiency power generation is achieved.

[Brief description of the drawings]

FIG. 1 is a diagram showing the relationship between tensile strength and C (%).

FIG. 2 is a diagram showing a relationship between tensile strength and Mo (%).

FIG. 3 is a diagram showing a relationship between an impact value and a tensile strength.

FIG. 4 is a front view of a steam turbine blade according to the present invention.

FIG. 5 is a side view of FIG. 4;

FIG. 6 is a plan view of the tip of FIGS. 4 and 5 as viewed from above.

FIG. 7 is a front view of the steam turbine blade of the present invention.

FIG. 8 is a side view of FIG. 7;

FIG. 9 is a front view of the steam turbine blade of the present invention.

FIG. 10 is a side view of FIG. 9;

FIG. 11 is a sectional view of a high-pressure, medium-pressure steam turbine according to the present invention.

FIG. 12 is a perspective view of a steam turbine blade according to the present invention.

FIG. 13 is a perspective view of a steam turbine blade according to the present invention.

FIG. 14 is a sectional structural view of a low-pressure steam turbine according to the present invention.

FIG. 15 is a sectional view of a high- and medium-pressure steam turbine according to the present invention.

FIG. 16 is a sectional view of a rotor shaft for a high- and medium-pressure steam turbine according to the present invention.

FIG. 17 is a sectional view of a low-pressure steam turbine according to the present invention.

FIG. 18 is a sectional view of a rotor shaft for a low-pressure steam turbine according to the present invention.

FIG. 19 is a front view of a rotor shaft for a high-pressure turbine.

FIG. 20 is a front view of a rotor shaft for a medium-pressure turbine.

FIG. 21 is a sectional view of a rotor shaft for a high-medium pressure 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, 27 ... bearing, 28 ...
Main steam inlet, 29: 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… rotor blade, 42… stationary blade, 4
3 ... bearing, 44 ... rotor shaft, 51 ... wing, 52 ...
Wing implantation part, 53 ... pin insertion hole, 54 ... erosion shield, 55 ... tie boss, 56 ... welded part, 57 ... continuous cover.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Takeshi Onoda 3-1-1, Sakaimachi, Hitachi-shi, Ibaraki Pref. Hitachi Plant, Ltd. Hitachi Plant (72) Inventor Masao Shiga 3-chome, Bentencho, Hitachi-shi, Ibaraki No. 2 Hitachi Kyowa Engineering Co., Ltd. (72) Inventor Ryo Hiraga 4-6 Kanda Surugadai, Chiyoda-ku, Tokyo F-term in Hitachi, Ltd. (Reference) 3G002 EA06 FA01 FA04 FA08 FA10 FA10 FB00

Claims (19)

[Claims] 1. The wing portion has a length of at least 40 inches, the inclination of the wing portion in the width direction is substantially parallel to the axial direction of the rotating shaft in the vicinity of the implanted portion, and the tip of the wing portion is oriented in the axial direction. 6
A steam turbine blade inclined from 5 to 85 degrees and made of martensitic steel. 2. A martensitic steel having a 20 ° C. V notch impact value (kg-m / cm ² ) y equal to or greater than a value obtained from a tensile strength (kg / mm ² ) x at room temperature by the following formula: A steam turbine blade. y = −0.29x + 45 3. The wing length is not less than 45 inches for 3000 rpm or not less than 37.5 inches for 3600 rpm.
9 or more and 37.5 for 45 inches or more
A steam turbine blade having a fork shape of 7 or more per inch or an inverted Christmas tree shape having four or more projections and made of martensitic steel. 4. A steam turbine blade having a blade length of 40 inches or more and a martensitic steel having an implanted portion width of 2.1 to 2.5 times the width of the tip of the blade portion. 5. A wing length of at least 45 inches for 3000 rpm or 37.5 inches for 3600 rpm.
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 wing portion side. A steam turbine blade characterized by being made of martensite steel larger than the opposite side. 6. The martensitic steel according to claim 1, wherein said martensitic steel is 0.15 to 0.25% by weight, Si
0.25% or less, Mn 0.90% or less, Cr 8.0 to 13.
0%, Ni2 to 3.5%, Mo1.5 to 3.5%, V0.
Steam containing 0.05 to 0.35%, a total amount of one or two of Nb and Ta being 0.02 to 0.20%, and 0.04 to 0.15%, and having a fully tempered martensite structure. Turbine blades. 7. A composition comprising 0.19 to 0.25% of C and 0.2% of Si by weight.
25% or less, Mn 0.90% or less, Cr 8.0 to 13.0
%, Ni 2 to 3.5%, Mo 1.5 to 3.5%, V 0.05
Steam turbine having a total tempered martensitic structure containing 0.02 to 0.20% and N in a total amount of 0.02 to 0.20% and N 0.04 to 0.15% Wings. 8. A steam turbine in which a high-pressure turbine, a medium-pressure turbine and two low-pressure turbines are connected in tandem, wherein a steam inlet temperature to the high-pressure turbine and the medium-pressure turbine is 593 ° C. or more and a rotation speed is 3000 or 3600 rpm. In the power plant, the last stage rotor blade of each of the low-pressure turbines has a blade length (inch) × the rotation speed (rpm) of 1
29,000 or more, made of martensitic steel, and the average diameter of the last stage blade is 3520 with respect to the 3000 rpm.
A steam turbine power plant characterized by being at least 2,930 mm for at least 3600 rpm. 9. A high-pressure turbine, a low-pressure turbine, and a generator, and an intermediate-pressure turbine, a low-pressure turbine, and a generator are connected in tandem, and the steam inlet temperature to the high-pressure turbine and the intermediate-pressure turbine is 593 ° C. or more and the number of revolutions is 3000. Or 3600rp
m, the final stage rotor blade of each of the low-pressure turbines is [blade length (inch) ×
The rotation speed (rpm)] is 129000 or more, the steel is made of martensitic steel, and the average diameter of the final stage rotor blade is 30
2800 mm or more for 00 rpm or 2 for 3600 rpm
A steam turbine power plant characterized by being 330 mm or more. 10. A high-pressure / medium-pressure unit integrated turbine and one or two low-pressure turbines are connected in tandem, and the steam inlet temperature to the high-pressure unit and the medium-pressure unit is 593 ° C. or more and the number of revolutions is 3000 Alternatively, in a steam turbine power plant of 3600 rpm, the last stage rotor blade of each of the low-pressure turbines has a blade length (inch) × the rotation speed (rpm) of 1
29000 or more, made of martensitic steel, and the average diameter of the last stage blade is 2540 for the 3000 rpm.
A steam turbine power plant characterized by being at least 2 mm for at least 3600 rpm. 11. A steam turbine power plant wherein the last stage rotor blade comprises the steam turbine blade according to any one of claims 1 to 7. 12. A rotor shaft, a moving blade implanted on the rotor shaft, a stationary blade for guiding the flow of water vapor to the moving blade, and a casing for holding the stationary blade, wherein the number of rotations is
In a low-pressure steam turbine of 3000 rpm or 3600 rpm, the rotor blades have left-right symmetrical five or more stages, and a double-flow structure in which the first stage is implanted in the center of the rotor shaft,
The final stage rotor is [wing length (inch) x the number of rotations (rp
m)] is 129000 or more and is made of martensite steel, and the average diameter of the last stage rotor blade is 3520 mm or more for the 3000 rpm or 2930 mm for the 3600 rpm.
mm. 13. A rotor shaft, a moving blade implanted on the rotor shaft, a stationary blade for guiding inflow of steam to the rotating blade, and an inner casing for holding the stationary blade, wherein the number of revolutions is In a low-pressure steam turbine of 3000 rpm or 3600 rpm, the moving blade has a double-flow structure having five or more stages symmetrically left and right, and the last stage moving blade has a blade length (inch) ×
The rotation speed (rpm)] is 129000 or more, the steel is made of martensitic steel, and the average diameter of the final stage rotor blade is 30
A low-pressure steam turbine characterized by being at least 2800 mm at 00 rpm or at least 2330 mm at 3600 rpm. 14. A low-pressure steam turbine having a rotor shaft, a moving blade implanted on the rotor shaft, a stationary blade for guiding the flow of steam to the rotating blade, and a casing for holding the stationary blade. The moving blade has a double-flow structure having at least five stages symmetrically left and right, and the last stage moving blade has a blade length (inch) × the number of revolutions (rpm) of 129000 or more and is made of martensitic steel. The average diameter of the moving blade is 2540 mm or more or 3600 rpm for the 3000 rpm.
A low-pressure steam turbine characterized by being at least 2120 mm. 15. A low-pressure steam turbine having a rotor shaft, a moving blade implanted on the rotor shaft, a stationary blade for guiding the flow of steam to the rotating blade, and a casing for holding the stationary blade. A low-pressure steam turbine comprising a steam turbine blade according to any one of claims 1 to 7, wherein a last stage of the rotor blade is provided. 16. The method according to claim 12, wherein
A low-pressure steam turbine comprising the steam turbine blade according to any one of claims 1 to 7, wherein the last stage rotor blade is provided. 17. The rotor shaft according to claim 1, wherein a tensile strength at a room temperature in a central portion of the rotor shaft is 92 kg / mm ² or more and F
The low-pressure steam turbine according to any one of claims 12 to 16, wherein the ATT is made of bainite steel having an ATT of -5C or less. 18. The bainite steel may have a C0.2 weight.
0 to 0.28%, Si 0.15% or less, Mn 0.25% or less, Ni 3.25 to 4.25%, Cr 1.6 to 2.5%, M
The low-pressure steam turbine according to claim 17, comprising a forged steel containing 0.25 to 0.60% and V 0.05 to 0.20%. 19. A composition comprising 0.19 to 0.25% by weight of Si,
0.25% or less, Mn 0.90% or less, Cr 8.0 to 13.
0%, Ni 2-3.5%, Mo 1.5-3.5%, V0.0
A high-strength martensitic steel characterized in that the total amount of one or two of Nb and Ta contains 0.02 to 0.20% and 0.04 to 0.15% of Nb and Ta. .