JP2762015B2 - Manufacturing method of steam turbine diaphragm - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a steam turbine diaphragm which can easily incorporate a nozzle blade having a three-dimensional curved surface.

[0002]

2. Description of the Related Art FIG. 7 is a plan view showing a case where a steam turbine diaphragm is halved. In the figure, reference numeral 1 denotes a plurality of annularly arranged nozzle blades, and reference numerals 2 and 3 denote nozzle blades 1.
And 4 are an outer ring fixed to the outer peripheral surface of the outer partition plate 2 and 5 are inner partition plates 3, respectively.
The inner ring is fixed to the inner peripheral surface of the inner ring.

FIG. 8 is a sectional view taken along line AA of FIG. The shape of the hole 2A of the outer partition plate 2 is one end face 6 of the nozzle blade 1.
The hole 3A of the inner partition plate 3 is formed so as to match the other end surface 7 of the nozzle blade 1. The one end face 6 side of the nozzle blade 1 has a hole 2A of the outer partition plate 2.
The other end face 7 is fitted into the hole 3A of the inner partition plate 3 and fixed by welding 8 and 9, respectively. An outer ring 4 is fixed to the outer peripheral surface of the outer partition plate 2 by welding 10,
An inner ring 5 is fixed to the inner peripheral surface of the inner partition plate 3 by welding 11.

A conventional example showing a method of assembling the nozzle blade 1 and the partition plates 2 and 3 is disclosed in Japanese Patent Application Laid-Open No. 58-150.
No. 005 can be mentioned. In this conventional example, as shown in FIG. 9, holes 2A and 3A are provided in advance in the outer partition plate 2 and the inner partition plate 3, respectively, and when assembling, the end face 7 side of the nozzle blade 1 is indicated by an arrow B as shown in FIG. Into the hole 2A from the outer peripheral surface side of the outer partition plate 2,
The nozzle blade 1 is pushed into the inner partition plate 3 as it is to fit the end face 7 side of the nozzle blade 1 into the hole 3A of the inner partition plate 3 and the end 6 of the nozzle blade 1 is inserted into the hole 2A of the outer partition plate 2. They are fitted. In this case, the cross-sectional shape of the nozzle blade 1 needs to be a shape passing through the hole 2A of the outer partition plate 2 throughout.

[0005]

However, in the conventional assembling method as described above, the nozzle blades are inserted in the radial direction of the diaphragm main body through the holes of the outer partition plate, and all the nozzle blades are inserted into the holes of the inner partition plate. In addition, the cross-section of the nozzle blade must all pass through a hole provided in the outer partition plate. For this reason, in the case of a nozzle blade having a three-dimensional curved surface, the outer partition plate and the end of the nozzle blade are cut off at the time of assembly, and the nozzle blade is inserted into the hole of the outer partition plate. .

However, when the outer partition plate and the end of the nozzle blade are cut off in this way, a gap is formed between the nozzle blade and the partition plate, and it is necessary to fill the gap after assembly, which requires extra work. As the number of nozzle blades increases, the cross-sectional shape of the nozzle blade may be impaired due to the cutting of the nozzle blade, and the accuracy of the nozzle blade may be reduced.

An object of the present invention is to provide a method of manufacturing a steam turbine diaphragm which is easy to manufacture and can maintain high accuracy of the nozzle blade even if the nozzle blade having a three-dimensional curved surface is incorporated. That is.

[0008]

In order to achieve the above-mentioned object, the present invention provides a method for fitting both ends of a nozzle blade into holes of an outer partition plate and an inner partition plate formed in a ring shape. The method of manufacturing a steam turbine diaphragm, wherein both ends of the nozzle blade are welded to the holes, an outer ring is welded to an outer peripheral surface of the outer partition plate, and an inner ring is welded to an inner peripheral surface of the inner partition plate. The cross-sectional shape of both ends of the wing, the distance from the end surface at the outer partition plate end to the range where the distance from the end surface is equal to the value obtained by adding the plate thicknesses of the two partition plates, the distance from the end surface at the inner partition plate end is The diaphragm body is processed in the same shape as the end face along the radial direction of the diaphragm main body until the thickness becomes equal to the thickness of the inner partition plate, and the outer partition plate side end of the nozzle blade is outside the hole of the outer partition plate. When inserted from the inner peripheral side of the partition plate, the nozzle The nozzle wing is pushed further so that the end face of the inner partition plate projects from the outer peripheral surface of the outer partition plate by the thickness of the inner partition plate, and then the inner partition plate side end of the nozzle wing is inserted into the hole of the inner partition plate. When inserted from the outer peripheral side of the inner partition,
The nozzle blade is returned to the inner partition plate side by the thickness of the inner partition plate that has been pushed in excessively, and finally, both ends of the nozzle blade are welded to the two holes.

Further, according to the present invention, both ends of the nozzle blade are fitted into holes of an outer partition plate and an inner partition plate formed in a ring shape, and both ends of the nozzle blade are welded to the holes. A method for manufacturing a steam turbine diaphragm in which an outer ring is welded to an outer peripheral surface of the outer partition plate and an inner ring is welded to an inner peripheral surface of the inner partition plate, wherein a cross-sectional shape of both ends of the nozzle blade is changed to an inner partition plate side. At the end, to the extent that the distance from the end face is equal to the value obtained by adding the thickness of the two partition plates
At the end of the outer partition plate, the inner partition plate of the nozzle blade is processed in the same shape as the end surface along the radial direction of the diaphragm body until the distance from the end surface becomes equal to the thickness of the outer partition plate. When the side end is inserted into the hole of the inner partition plate from the outer peripheral surface side of the inner partition plate, the nozzle blades project so that the end surface of the nozzle blade protrudes from the inner peripheral surface of the inner partition plate by the thickness of the outer partition plate. When the end of the outer partition plate side of the nozzle blade is inserted into the hole of the outer partition plate from the inner peripheral surface side of the outer partition plate, the thickness of the outer partition plate that is excessively pressed is That is, the nozzle blade is returned to the outer partition plate side by an amount, and finally, both ends of the nozzle blade are welded to the holes.

Further, according to the present invention, both ends of a nozzle blade are fitted into holes of an outer partition plate and an inner partition plate formed in a ring shape, and both ends of the nozzle blade are welded to the holes. A method for manufacturing a steam turbine diaphragm in which an outer ring is welded to an outer peripheral surface of the outer partition plate, and an inner ring is welded to an inner peripheral surface of the inner partition plate, wherein a cross-sectional shape of both end portions of the nozzle blade is a predetermined range from an end surface. Up to the same shape as the end face along the radial direction of the diaphragm body,
When the outer partition plate side end of the nozzle blade is inserted into the hole of the outer partition plate from the inner peripheral surface side of the outer partition plate, the inner partition plate side end of the nozzle blade fits into the hole of the inner partition plate. When the nozzle blades are pushed further into the outer partition plate side by the length of the nozzle partition, and then the inner partition plate side end of the nozzle blade is inserted into the hole of the inner partition plate from the outer peripheral surface side of the inner partition plate. Then, the nozzle blades are returned to the inner partition plate by the length of the extra pushing, and finally, both ends of the nozzle blades are welded to the holes.

Further, according to the present invention, both ends of the nozzle blade are fitted into holes of an outer partition plate and an inner partition plate formed in a ring shape, and both ends of the nozzle blade are welded to the holes. A method for manufacturing a steam turbine diaphragm in which an outer ring is welded to an outer peripheral surface of the outer partition plate, and an inner ring is welded to an inner peripheral surface of the inner partition plate, wherein a cross-sectional shape of both end portions of the nozzle blade is a predetermined range from an end surface. Until the diaphragm body is processed in the same shape as the end face along the radial direction, when the inner partition plate side end of the nozzle blade is inserted into the hole of the inner partition plate from the outer peripheral surface side of the inner partition plate, The nozzle wings are pushed further into the inner partition by the length of the outer partition plate side end of the nozzle blade fitted into the hole of the outer partition plate, and then the outer partition plate side end of the nozzle blade is Into the hole of the outer partition plate from the inner peripheral surface side of the outer partition plate. When the extra returns the by the length nozzle blade is pushed to the outer partition plate side, finally, it is to weld the ends of the nozzle blade to the both holes.

[0012]

According to the present invention, both ends of the nozzle are cut at the time of processing a single piece of the nozzle blade, and the cross-sectional shape of both ends is processed in the radial direction of the diaphragm body to have the same shape as the end face. Then, the range of the cutting process is the inner partition plate end until the distance from the end surface at the outer partition plate end becomes equal to the value obtained by adding the thickness of the outer partition plate and the thickness of the inner partition plate. In this case, the distance from the end surface is set to a point where the thickness becomes equal to the thickness of the inner partition plate. By performing such a cutting process, even if the surface shape of the nozzle blade is a three-dimensional curved surface, the nozzle blade can be easily incorporated into the outer partition plate and the inner partition plate. That is, when one end of the nozzle blade is inserted into the hole of the outer partition plate from the inner peripheral surface side of the outer partition plate, the nozzle is so formed that one end surface protrudes from the outer peripheral surface of the outer partition plate by the thickness of the inner partition plate. By pushing the wings in, the space for placing the inner partition plate on the other end side of the nozzle wing is secured, and after arranging the inner partition plate in this space, the nozzle wings are moved by the thickness of the inner partition plate. By returning to the partition plate side, the nozzle blades can be easily incorporated into the outer partition plate and the inner partition plate. Finally, both ends of the assembled nozzle blade are fixed to the outer partition plate and the inner partition plate by welding.

In the above description, the nozzle blades are inserted into the holes in the outer partition plate and then into the holes in the inner partition plate. However, the nozzle blades are inserted into the holes in the inner partition plate and then into the holes in the outer partition plate. It may be inserted in. In this case, the range to be processed into the same shape as the end face is such that the distance from the end face at the inner partition side end becomes equal to the value obtained by adding the thickness of the outer partition plate and the thickness of the inner partition plate. At the end of the partition plate, the distance from the end surface is set to a position where the thickness becomes equal to the thickness of the outer partition plate. Then, when the nozzle blade is inserted into the hole of the inner partition plate, the nozzle blade is pushed so that the end surface of the nozzle blade protrudes from the inner peripheral surface of the inner partition plate by the thickness of the outer partition plate, and the nozzle blade is inserted into the outer partition plate. When inserted into the hole, it is necessary to return the nozzle blades to the outer partition by the thickness of the outer partition.

[0014]

An embodiment of the present invention will be described below with reference to the drawings. The same parts as those in the prior art are denoted by the same reference numerals. FIG. 1 is a diagram showing a state where nozzle wings are incorporated into an outer partition plate and an inner partition plate by the manufacturing method of the present invention, and FIG. 2 is a perspective view thereof. As shown in the drawing, the nozzle blade 1 has a three-dimensional curved surface shape of a central portion 1a. That is, in the central portion 1a, when the nozzle blade 1 is cut into a circle, the cross-sectional shape differs depending on the position of the cut.

The outer partition plate side end (right end) 1b of the nozzle blade 1 is formed in the same shape as the end surface 6 along the radial direction of the diaphragm main body. The range of the outer partition plate side end portion 1b includes the thickness 2a of the outer partition plate 2 and the thickness 3a of the inner partition plate 3.
Is set to be equal to the value obtained by adding An inner partition plate side end (left end) 1c of the nozzle blade 1 is formed in the same shape as the end face 7 along the radial direction of the diaphragm main body. The range of the inner partition plate side end 1c is set to be equal to the plate thickness 3a of the inner partition plate 3. The left and right end portions 1b and 1c of the nozzle blade 1 are cut by an NC lathe or the like.

The hole 2A of the outer partition plate 2 and the hole 3A of the inner partition plate 3 are formed by water jet cutting or wire cut cutting which does not affect the cut surface by heat.
In this case, point sequence data depicting the same cross-sectional shape as the end face 6 of the nozzle blade 1 is used for the outer partition plate 2, and point sequence data depicting the same cross-sectional shape as the end surface 7 of the nozzle blade 1 is used for the inner partition plate 3. Processed. Thereby, the hole 2A of the outer partition plate 2 and the hole 3A of the inner partition plate 3 can be matched with the insertion direction of the nozzle blade 1, and the hole 2A of the outer partition plate 2 and the hole 3A of the inner partition plate 3 When the nozzle blade 1 is inserted, the insertion operation can be performed smoothly.

The nozzle blade 1 is connected to an outer partition plate 2 and an inner partition plate 3.
First, the outer partition plate side end 1b of the nozzle blade 1 is inserted into the hole 2A of the outer partition plate 2, and the end surface 6 protrudes from the outer partition plate outer peripheral surface 12 by the thickness 3a of the inner partition plate. The nozzle blade 1 is pushed in until it is in a state where the nozzle blades 1 are in a closed state. Then, the same operation is performed for all of the plurality of nozzle blades 1.

With the above arrangement, a space for disposing the inner partition plate 3 at the center of the diaphragm body of the nozzle blade 1 set on the outer partition plate 2 (end side of the inner partition plate) is secured. The inner partition plate 3 can be easily arranged in this space.

When the inner partition plate 3 is disposed in the space, the inner partition plate side end 1c of the nozzle blade 1 is inserted into the hole 3A of the inner partition plate 3, and the end surface 7 is turned as shown by the arrow C in FIG. The nozzle blade 1 is pushed in until it matches the inner peripheral surface 13 of the inner partition plate. Then, the same operation is performed for all the plurality of nozzle blades 1.

Next, as shown in FIG.
Along the contours of both end faces 6, 7 of the nozzle blade 1 inserted in
Laser welding (or pulse TIG welding) 8 is performed to fix the nozzle blade 1 to the outer partition plate 2 and the inner partition plate 3 without using a filler material. Further, the outer peripheral surface 12 of the outer partition plate and the inner peripheral surface 13 of the inner partition plate are finished by machining. Since the diaphragm is large, it is generally halved in consideration of, for example, transportation. FIG. 7 described above shows a half of the state.

The outer partition plate 2 and the inner partition plate 3 in which the nozzle blades 1 are incorporated are halved. When the diaphragm is to be completed, a half-ring shaped outer ring 4 is provided on the outside (outer peripheral surface 12 of the outer partition plate) of the half-divided outer partition plate 2, and an inner ring (inner partition) of the half-shaped inner partition plate 3 is provided. The semi-ring inner ring 5 is fixed to the plate inner peripheral surface 13) by welding 10, 11 (see FIG. 4). In this case, as the weldings 10 and 11, it is preferable to perform electron beam welding that allows deep penetration into the groove surface.

FIG. 5 shows the manufacturing operation procedure described above. As shown in the figure, machining and the like are separately performed on the outer partition plate and the inner partition plate, the nozzle blade, the outer ring, and the inner ring. The illustrations shown in the figure schematically show how the diaphragm is assembled.

According to this embodiment, both ends 1 of the nozzle blade 1
b and 1c are holes 2A of the outer partition plate 2 and holes 3A of the inner partition plate 3
Since it has been machined in advance to meet the requirements, there is no need to cut off the nozzle blade tip that was carried out during assembly,
In addition, there is no need to perform an additional operation of filling or correcting the gap between the nozzle blade 1 and the two partition plates 2 and 3, and it is possible to improve the operation efficiency of manufacturing the turbine diaphragm.

In the present embodiment, the nozzle plates 1 are disposed between the outer partition plate 2 and the inner partition plate 3 in a state where the nozzle blades 1 are disposed between the outer partition plate 2 and the inner partition plate 3.
3, both ends 1b, 1c of the nozzle blade 1
However, even if it is eccentric with respect to a straight line passing through the center of the diaphragm main body, the positions of the hole 2A of the outer partition plate 2 and the hole 3A of the inner partition plate 3 are eccentric with each other in correspondence with both ends 1b and 1c of the nozzle blade 1. If formed, both ends 1b and 1c can be easily inserted into both holes 2A and 3A. This can be said for the case where the size and the shape of both ends 1b and 1c of the nozzle blade 1 are different from each other.

In the above description, the nozzle blade 1 was inserted into the hole 2A of the outer partition plate 2 and then inserted into the hole 3A of the inner partition plate 3. However, this order was reversed, and the nozzle blade 1 was inserted into the hole 3A of the inner partition plate 3. After insertion, it may be inserted into the hole 2A of the outer partition plate 2. In this case, the range of the inner partition plate side end 1c of the nozzle blade 1 is set to be equal to a value obtained by adding the outer partition plate thickness 2a and the outer partition plate thickness 3a. End 1
When c is inserted into the hole 3A of the inner partition plate 3, it is necessary to push the nozzle blade 1 so that the nozzle blade end surface 7 protrudes from the inner peripheral surface 13 of the inner partition plate by the outer partition plate thickness 2a.

FIG. 6 shows another embodiment of the present invention.
In this embodiment, both end portions 1b and 1c of the nozzle blades to be inserted into the hole 2A of the outer partition plate 2 and the hole 3A of the inner partition plate 3 are shortened. When the nozzle blade 1 is incorporated into the outer partition plate 2 and the inner partition plate 3, the outer partition plate side end 1b of the nozzle blade 1 is inserted into the hole 2A of the outer partition plate 2 and 1d (1d is 1 d).
The length of the nozzle wing 1 is further pushed in by an amount equal to or longer than c), then the inner partition plate side end 1c of the nozzle wing 1 is inserted into the hole 3A of the inner partition plate 3 and returned by 1d. To do. The recesses 2 are provided in the holes 2A, 3A of the partition plates 2, 3.
Since the nozzles B and 3B are formed, when the nozzle blade 1 is fixed to the outer partition plate 2 and the inner partition plate 3, it is necessary to build-up weld the recesses 2B and 3B using the filler metal 14 by means of, for example, chip welding. is there.

According to the present embodiment, the range of the exposed portion 1b when the diaphragm is completed can be suppressed as compared with the above-described embodiment, so that the main body portion of the nozzle blade (1a in FIG. 1) is reduced accordingly. Can be bigger. As a result, the shape of the nozzle blade 1 can be made close to the required design value, and an efficient diaphragm can be obtained.

[0028]

As described above, according to the present invention,
The nozzle blade having a three-dimensional curved surface can be easily incorporated into the outer partition plate and the inner partition plate, so that the turbine diaphragm can be easily manufactured.

Further, when the nozzle blades are incorporated into the outer partition plate and the inner partition plate, both ends of the nozzle blades and the holes of the partition plate are not cut away, so that a high-precision turbine diaphragm can be manufactured. Become.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a state where nozzle wings are incorporated into both partition plates by a manufacturing method of the present invention.

FIG. 2 is a perspective view of FIG.

FIG. 3 is a perspective view showing a state where a nozzle blade and both partition plates are fixed.

FIG. 4 is a sectional view showing a state in which an outer ring and an inner ring are joined to both partition plates.

FIG. 5 is a flowchart showing a procedure for manufacturing a turbine diaphragm.

FIG. 6 is a view showing another embodiment of the present invention.

FIG. 7 is a plan view of a half-divided turbine diaphragm.

FIG. 8 is a sectional view of a conventional turbine diaphragm.

FIG. 9 is an explanatory view showing a state in which nozzle wings are incorporated into both partition plates according to a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Nozzle blade 2 Outer partition plate 2A Outer partition plate hole 2B Outer partition plate side recess 3 Inner partition plate 3A Inner partition plate hole 3B Inner partition plate side recess 4 Outer ring 5 Inner ring 6 End face of outer partition plate end 7 End surface of inner partition plate side end 8-11 Welded part 12 Outer partition plate outer peripheral surface 13 Inner partition plate inner peripheral surface 14 Filler material

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Norio Kitamura 3-1-1, Sachimachi, Hitachi-shi, Ibaraki Hitachi, Ltd. Hitachi Plant (72) Inventor Masayoshi Matsuda 3-1-1, Sachimachi, Hitachi-shi, Ibaraki No. 1 Hitachi, Ltd. Hitachi Plant (56) References JP-A-57-179306 (JP, A) JP-A-61-265308 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB (Name) F01D 9/04

Claims (4)

(57) [Claims] An end portion of a nozzle blade is fitted into a hole of an outer partition plate and an inner partition plate formed in a ring shape, and both end portions of the nozzle blade are welded to the holes. In a method for manufacturing a steam turbine diaphragm, in which an outer ring is welded to an outer peripheral surface of a partition plate and an inner ring is welded to an inner peripheral surface of the inner partition plate, a cross-sectional shape of both end portions of the nozzle blade is an end surface at an end portion of the outer partition plate side. The radius of the diaphragm body until the distance from the inner partition plate to the range where the distance from the end face becomes equal to the value obtained by adding the plate thicknesses of the two partition plates, and the distance from the end face becomes equal to the plate thickness of the inner partition plate. When processed into the same shape as the end face along the direction, when the outer partition plate side end of the nozzle blade is inserted into the hole of the outer partition plate from the inner peripheral surface side of the outer partition plate, the end surface of the nozzle blade is From the outer peripheral surface of the outer partition by the thickness of the inner partition When the nozzle blades are pushed in excessively so as to come out, and then the inner partition plate side end of the nozzle blades is inserted into the hole of the inner partition plate from the outer peripheral surface side of the inner partition plate, A method for manufacturing a steam turbine diaphragm, comprising returning a nozzle blade to an inner partition plate side by a thickness of a partition plate, and finally welding both end portions of the nozzle blade to the holes. 2. Both ends of a nozzle blade are fitted into holes of an outer partition plate and an inner partition plate formed in a ring shape, and both ends of the nozzle blade are welded to the holes. In a method for manufacturing a steam turbine diaphragm, in which an outer ring is welded to an outer peripheral surface of a partition plate and an inner ring is welded to an inner peripheral surface of the inner partition plate, the cross-sectional shape of both end portions of the nozzle blade is set to an end surface at an end portion of the inner partition plate side. To the range where the distance from the outer partition plate side is equal to the value obtained by adding the plate thicknesses of the two partition plates, and to the range where the distance from the end face is equal to the plate thickness of the outer partition plate at the end of the outer partition plate, the radius of the diaphragm body. When processed into the same shape as the end surface along the direction, when the inner partition plate side end of the nozzle blade is inserted into the hole of the inner partition plate from the outer peripheral surface side of the inner partition plate, the end surface of the nozzle blade is From the inner peripheral surface of the inner divider by the thickness of the outer divider When the nozzle blade is pushed in excessively so as to come out, and then when the outer partition plate side end of the nozzle blade is inserted into the hole of the outer partition plate from the inner peripheral surface side of the outer partition plate, the excess pushed in A method for manufacturing a steam turbine diaphragm, comprising: returning a nozzle blade to the outer partition plate by a thickness of the outer partition plate, and finally welding both end portions of the nozzle blade to the holes. 3. Both ends of a nozzle blade are fitted into holes of an outer partition plate and an inner partition plate formed in a ring shape, and both ends of the nozzle blade are welded to the holes, and A method for manufacturing a steam turbine diaphragm, in which an outer ring is welded to an outer peripheral surface of a partition plate and an inner ring is welded to an inner peripheral surface of the inner partition plate, wherein a cross-sectional shape of both end portions of the nozzle blade is a diaphragm main body from an end surface to a predetermined range. When processed into the same shape as the end surface along the radial direction of the nozzle blade, when the outer partition plate side end of the nozzle blade is inserted into the hole of the outer partition plate from the inner peripheral surface side of the outer partition plate, The nozzle wings are pushed extra into the outer partitioning plate by an amount corresponding to the length of the inner partitioning plate side end fitted into the hole of the inner partitioning plate, and then the inner partitioning plate side end of the nozzle wing is inserted into the inner partitioning plate. When inserted from the outer peripheral surface side of the inner partition plate into the hole of the partition plate, Min back to the inner partition plate side length amount corresponding nozzle blade pushed, finally, the production method of a steam turbine diaphragm, characterized in that welding the two ends of the nozzle blade to the both holes. 4. Both ends of a nozzle blade are fitted into holes of an outer partition plate and an inner partition plate formed in a ring shape, and both ends of the nozzle blade are welded to the holes, In a method for manufacturing a steam turbine diaphragm in which an outer ring is welded to an outer peripheral surface of a partition plate and an inner ring is welded to an inner peripheral surface of the inner partition plate, the cross-sectional shape of both end portions of the nozzle blade is a diaphragm main body from an end surface to a predetermined range. When processed into the same shape as the end face along the radial direction of the nozzle blade, when the inner partition plate side end of the nozzle blade is inserted into the hole of the inner partition plate from the outer peripheral surface side of the inner partition plate, The nozzle wings are pushed further into the inner partition plate side by an amount corresponding to the length at which the partition plate side end is fitted into the hole of the outer partition plate, and then the outer partition plate side end of the nozzle wing is separated into the outer partition plate. When inserted into the hole of the plate from the inner peripheral surface side of the outer partition plate, Min returned to by the length nozzle blade is pushed to the outer partition plate side, finally, the production method of a steam turbine diaphragm, characterized in that welding the two ends of the nozzle blade to the both holes.