JP3850929B2 - Gas turbine blade repair method, repair device therefor, and gas turbine blade - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas turbine blade repair method and gas turbine blade and gas turbine blade repair device, and more particularly to a gas turbine in which build-up welding is performed on a damaged blade tip to restore the blade shape. It relates to wing repair technology.
[0002]
[Prior art]
In a gas turbine that is a part of the components of a thermal power plant, a moving blade is used in an extremely high temperature environment. For this reason, there is a possibility that the tip of the rotor blade may be worn or deteriorated due to high temperature oxidation during the service period, and there is a concern about the occurrence of defects such as cracks. In the case where the moving blade is restored to a service state by repair, overlay welding is one of the repair works. This is a construction in which the deteriorated portion is replenished by overlay welding on the deteriorated portion of the blade tip portion.
[0003]
In addition, as a thing relevant to the repair method of this kind gas turbine rotor blade, Unexamined-Japanese-Patent No. 3-33402 is mentioned, for example.
[0004]
[Problems to be solved by the invention]
Thus, generally, the gas turbine blade is restored by overlay welding. However, as shown in FIG. 13, the tip of the rotor blade 1 is a repair method by overlay welding. The shape of the deteriorated part 2 in the part is not uniform, and there are deteriorated parts in various states depending on the rotor blades. When repairing the deteriorated portion 2 by manual welding, there is a limit to control of heat input due to manual construction. The moving blade is made of a Ni-base superalloy and has high cracking susceptibility to hot cracking. Therefore, when the heat input is increased by manual welding, there is a possibility that new hot cracks may occur in the weld heat affected zone.
[0005]
In order to control the heat input state, it is desirable to automatically control the arc voltage according to the welding position. However, it is difficult to control the locally deteriorated portion 2 as shown in FIG. . Further, in order to perform welding according to the state of each deteriorated portion, it is necessary to individually input a welding locus corresponding to the shape of the deteriorated portion, and automation is difficult.
[0006]
Furthermore, when the tip of the rotor blade is overlay welded with a controlled amount of heat input, there is a possibility that a poorly welded portion may occur in the vicinity of the welded portion in the conventional technique in which the weld surface is flat.
[0007]
The present invention has been made in view of the above, and an object of the present invention is to easily perform automatic welding with controlled heat input on a gas turbine rotor blade having a deteriorated tip, and a welding failure. It is in providing the construction method which forms the sound build-up weld part which does not generate | occur | produce, and the gas turbine rotor blade which has the sound build-up weld part without a welding defect.
[0008]
[Means for Solving the Problems]
That is, according to the present invention, in the construction for repairing the tip portion of the gas turbine rotor blade by overlay welding, the tip portion is cut or ground into a predetermined shape and the surface is surface-finished before welding, and then overlay welding is performed. It is intended to achieve the intended purpose.
[0009]
Further, in the present invention, in the construction for repairing the tip of the gas turbine blade by overlay welding, the tip is cut or ground into a predetermined shape parallel to the original tip of the blade before welding. After the surface is finished, overlay welding is performed. Also, in repairing the tip of a gas turbine blade by overlay welding, the tip is cut or ground into a predetermined shape having a certain inclination from the original tip of the blade before welding. After the surface is finished, overlay welding is performed.
[0010]
Further, the present invention provides a method for repairing the tip of a gas turbine rotor blade by overlay welding, cutting or grinding the tip into a predetermined shape before the welding, and then finishing the surface. The welding position and the welding conditions at each part of the welding target part are input in advance to the drive mechanism of the welding torch and the control mechanism of the welding conditions, and overlay welding is performed. In addition, overlay welding is performed with the rotor blade being incorporated in the turbine disk.
[0011]
In the present invention, in the construction for repairing the tip portion of the gas turbine rotor blade by overlay welding, after the tip portion is cut or ground into a predetermined shape before the welding construction, the edge portion of the surface from the center portion Is finished so that it becomes higher, and overlay welding is performed. In addition, the shape of the tip, which is cut or ground before the welding process and the surface is finished, is incorporated into the turbine disk of the blade, the size of the blade, the material of the blade, the service environment of the blade, or the It is determined according to the service life of the wing.
[0012]
Further, in the above-described repair work, the present invention finishes the repaired part to the original shape of the gas turbine rotor blade after the overlay welding. Further, in the above repair work, preheating conditions or cooling conditions are set during or after overlay welding according to the shape of the surface cut or ground before the welding work. In addition, the blade group is formed so as to have a fixed welded portion at the tip.
[0013]
In addition, the shape or size of the built-up weld at the tip is the stage or size of the blade, the material of the blade, the service environment before welding of the blade, or the state before welding of the blade. The present invention provides a gas turbine rotor blade characterized by being determined according to the years of service. Further, the present invention provides a gas turbine rotor blade characterized in that a rotor blade tip including a build-up weld has the same shape as the rotor blade tip at the time of manufacturing the rotor blade.
[0014]
The present invention also includes a welding torch, a welding power source, a filler material supply mechanism, a gas shield mechanism, a moving blade preheating mechanism or cooling mechanism, a welding torch drive mechanism, a welded portion monitoring mechanism, a welding line tracking control mechanism, and welding conditions. And a control mechanism for determining that the welding target part at the tip of the gas turbine rotor blade has a predetermined shape and a control mechanism for welding by correcting an error from the predetermined shape. It is a thing.
[0015]
That is, in the repair method of the gas turbine blade formed in this way, the damaged portion of the gas turbine blade is cut into a predetermined shape, and the cut surface is surface-finished, and then the surface-finished portion is applied. Since overlay welding is performed, the welding target part is processed into a fixed shape, so it is possible to easily set welding conditions such as welding current, welding voltage, arc length, and heat input control. In addition, since the wing is processed into a constant shape for any wing regardless of the shape of the original deteriorated part, it can be applied to any wing under constant welding conditions. This makes it possible to make the quality of the repaired portion made of the welded portion uniform without variation by the blades.
[0016]
In addition, by performing build-up welding after cutting or grinding the tip part into a certain shape before welding work and finishing the cut surface, it is possible to form a sound build-up weld part that does not cause welding defects. . In addition, since the welding target part after the tip part is processed into a constant shape has the same shape, the present invention repairs a series of moving blades constituting the stage by inputting the set condition once in each stage. This makes it possible to significantly reduce the time required for repair work.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail based on the illustrated embodiments. FIG. 1 shows the repaired state of the gas turbine rotor blade. In the present embodiment, for example, as shown in FIG. 1, the welding method is arc welding in which an arc is generated between the electrode and the base material. However, the present invention is not limited to TIG arc, plasma arc, laser, etc. Even when such a welding heat source is used, it can be implemented.
[0018]
[Embodiment 1]
The repairing operation of the gas turbine rotor blade according to the present invention, in which the tip portion is cut into a predetermined shape before the welding operation and the cut surface is surface-finished and then subjected to overlay welding, will be described with reference to FIGS. 1A to 1C are views of the vicinity of the tip of the gas turbine rotor blade as seen from the side. FIG. 4A shows a moving blade with a deteriorated tip portion before repair. When repairing the moving blade 1, first, the tip including the deteriorated portion 2 is cut or ground into a certain shape as shown in FIG. By this cutting or grinding operation, the surface 4 to be welded, which is the object of overlay welding, has a constant shape regardless of the shape of the degraded part 3 that has been cut or ground.
[0019]
Further, in the above construction, when the occurrence position of the deteriorated portion in the rotor blade is not unevenly distributed, the posture of overlay welding is always performed by cutting or grinding in parallel to the original tip as shown in FIG. It is desirable to make it downward and to make the overlay shape uniform with respect to welding conditions. However, when the occurrence position of the deteriorated portion 3 in the moving blade is unevenly distributed, it is more efficient to cut or grind so as to cover the uneven position of the deteriorated portion 3 as shown in FIG. In this case, in order to stabilize the welding work, it is desirable to cut or grind into a predetermined shape having a certain inclination angle from the original tip surface of the rotor blade.
[0020]
In addition, when the shape or uneven distribution of the deteriorated part in the moving blade varies depending on the stage incorporated in the turbine disk of the moving blade, the size of the moving blade, the material of the moving blade, the operating environment of the moving blade, or the service life of the moving blade, In order to form the built-up part shape according to the said conditions, it is desirable to cut or grind the shape according to the said conditions.
[0021]
Next, with respect to welding object plane 4 after cutting or grinding construction subjected to front surface finishing, performing overlay welding as shown in Figure 1 (c). In the present invention, since the welding target part is processed into a fixed shape, it is possible to easily set welding conditions such as a welding current, a welding voltage, and an arc length and to control heat input. In addition, regardless of the shape of the original deteriorated part 3, since it is processed into a constant shape for any moving blade, it can be applied to any moving blade under constant welding conditions, The quality of the repair part consisting of 5 is made uniform without variation due to the moving blades.
[0022]
As described above, according to the present invention, a sound build-up welded portion that does not cause a welding failure by cutting or grinding the tip portion into a fixed shape and finishing the cut surface before welding is performed. Can be formed.
[0023]
[Embodiment 2]
A repair method according to the present invention, in which overlay welding is performed by inputting the welding position in the welding target portion and the welding conditions in each part to the driving mechanism of the welding torch and the control mechanism of the welding conditions in advance, with reference to FIGS. I will explain.
[0024]
FIG. 3 is a side view of a moving blade whose surface is finished by processing the tip portion into a certain shape. In the case of moving blades of the same size, the surface 4 to be welded after finishing shown in FIG. 3 has the same shape. Therefore, as shown in FIG. 4, a moving trajectory of the welding torch 6 following the surface to be welded 4 is input in advance from the control device 20 that controls the driving mechanism 11 of the welding torch, thereby moving the moving blades of the same size. In FIG. 1, regardless of the shape of the deteriorated portion 3 existing before the repair work, the overlay welding work shown in FIG. 4 can be automatically performed on a plurality of moving blades by a series of flow operations.
[0025]
Further, it is desirable that the welding conditions in each part of the surface 4 to be welded in FIG. 4 are appropriately set according to the respective positions and input from the control device 20 in accordance with the movement trajectory or the time from the start of welding. .
[0026]
As described above, in the present invention, the front end portion is cut or ground into a certain shape and the cut surface is surface-finished before welding, and then the movement trajectory of the welding torch following the weld line and the welding conditions for each part By inputting the て and performing overlay welding, it is possible to automate repair construction and to form a sound overlay weld portion that does not cause welding defects.
[0027]
[Embodiment 3]
A repair method according to the present invention, in which build-up welding is performed with a rotor blade being incorporated in a turbine disk, will be described with reference to FIGS. FIG. 5 is a cross-sectional view of repairing a moving blade incorporated in a turbine disk.
[0028]
As shown in FIG. 5, the welding torch 6 is set on the moving blade 1 whose surface is finished by cutting or grinding the tip portion into a certain shape by the torch drive mechanism 11 attached to the crane 10. The torch 6 is moved by the drive mechanism 11 so as to follow the surface 4 to be welded shown in FIG. The status of overlay welding is monitored by the monitoring monitor camera 12 and controlled so that proper repair is performed. After the completion of repair work for one moving blade, the torch 6 is set to the next moving blade.
[0029]
FIG. 6 is a diagram illustrating only the turbine blades and the moving blades at a certain stage and picking up only the two typical angles of the moving blades. In setting the torch, the torch may be moved within a range where the influence of the torch angle, that is, the welding position can be ignored. However, under the condition that the welding position becomes a problem, the turbine disk 9 is rotated as shown in FIG. The torch 6 is set on the moving blade 1 to be repaired next.
[0030]
Since the size of the gas turbine blade is different for each stage, it is necessary to set the welding line locus and welding conditions for each stage. However, the series of blades in each stage are the same size, and the tip according to the present invention is used. The welding object part after processing a part into a fixed shape has the same shape. For this reason, in the present invention, it is possible to repair a series of moving blades constituting the stage by inputting the set condition once in each stage, and the time for repairing can be greatly shortened.
[0031]
[Embodiment 4]
FIG. 7 shows a repair method for a gas turbine blade according to the present invention, in which the tip portion is cut or ground into a predetermined shape, and then the edge of the surface is finished so as to be higher than the center portion, and overlay welding is performed. This will be described with reference to FIG.
[0032]
7 and 8 show cross sections of the blade tip perpendicular to the welding direction. As shown in FIG. 7 (a), when the edge portion 13 and the center portion 14 of the surface 4 to be welded are finished to the same height, overlay welding is performed with low heat input to prevent high-temperature cracking due to the thermal effect during welding. Then, depending on the welding conditions, the edge portion 13 may be poorly welded as shown in FIG. Further, when welding is carried out with a large heat input to melt the edge, depending on the welding conditions, a hot crack 16 may occur in the heat affected zone 15 as shown in FIG.
[0033]
In the present invention, as shown in FIG. 8 (a), the edge 13 of the surface to be welded is finished so as to be higher than the central portion 14, and overlay welding is performed. In this way, as shown in FIG. 8 (b), even when welding is performed with low heat input, the edge 13 is sufficiently melted and a sound build-up in which high temperature cracking does not occur in the heat affected zone 15 is achieved. A weld can be formed.
[0034]
[Embodiment 5]
FIG. 9 shows a method for repairing a gas turbine rotor blade according to the present invention, in which the tip portion is cut or ground into a predetermined shape, then finished so that the edge of the surface becomes higher than the center portion, and overlay welding is performed. This will be described with reference to FIG.
[0035]
FIG. 9 is a side view of the gas turbine rotor blade in which the repaired portion is finished into the original shape of the gas turbine rotor blade after overlay welding. After repairing the gas turbine rotor blade, the ceramic layer 18 is coated and used again as shown in FIG. In the present invention, as shown in FIG. 9, the repaired portion 17 at the tip of the moving blade is finished to the original shape at the time of manufacturing the moving blade, thereby eliminating the unevenness of the build-up welded portion, and close contact during recoating as shown in FIG. It is possible to apply a good coating.
[0036]
[Embodiment 6]
A method for repairing a gas turbine rotor blade according to the present invention, wherein preheating conditions or cooling conditions are set during or after overlay welding according to the shape of the surface cut or ground before welding. Will be described with reference to FIGS. 11 and 12. When the portion cut or ground to make the tip portion according to the present invention have a predetermined shape is large, it is desirable that the amount of overlaying is large in order to increase the construction efficiency.
[0037]
However, in order to increase the amount of filler for overlaying, welding with a large amount of heat input is required, which may increase the crack sensitivity shown in FIG. In this case, it is effective to perform overlay welding while preheating or cooling the rotor blade. This preheating condition or cooling condition is set according to the predetermined shape of the rotor blade tip processed. In the present invention, the tip of the moving blade is determined in a predetermined shape according to the stage incorporated in the turbine disk of the moving blade, the size of the moving blade, the material of the moving blade, the operating environment of the moving blade, or the service life of the moving blade. Each preheating condition or cooling condition set in accordance with a predetermined shape can have a certain heat history.
[0038]
FIG. 11 is a diagram showing a construction in which a heating mechanism is provided on the outer side of the moving blade to build-up the tip portion. The outside of the heat affected zone of the moving blade 1 is heated by bringing the heating mechanism 21 constituted by a high-frequency heating mechanism or an arc lamp into contact with the outside of the tip of the moving blade 1 in the vicinity of the tip. For this reason, the preheating effect or the afterheating effect at the time of welding in the rotor blade increased, and the cooling rate of the heat affected zone became extremely slow. As a result, the tensile stress generated in the heat-affected zone is relaxed, and a sound build-up repair weld that does not cause high-temperature cracking even when applied under welding conditions with a large heat input in order to increase the amount of build-up is achieved. It has become possible.
[0039]
FIG. 12 is a diagram showing a construction in which a water cooling mechanism is provided on the outer side of the moving blade to build-up the tip portion. By bringing the water-cooled Cu plate 25 into contact with the outside in the vicinity of the tip of the rotor blade 1 processed into a predetermined shape, the outside of the heat affected zone of the rotor blade 1 is cooled. For this reason, the conduction of heat received during welding of the rotor blades was accelerated, and the heat-affected zone was rapidly cooled. As a result, sound build-up repair welding that does not cause hot cracking is possible even when the welding is performed under a large heat input in order to increase the amount of build-up.
[0040]
[Embodiment 7]
The construction of the gas turbine rotor blade having the construction or the built-up portion according to the present invention is performed by, for example, a welding apparatus shown in FIG. FIG. 15 shows the welding torch 6, the welding power source 29, the filler material supply mechanism 30, the gas shield mechanism supplied from the gas cylinder 38 through the gas pipe 39, the preheating or cooling mechanism 32 of the rotor blade 1, the preheating condition or the cooling condition control. A mechanism 33, a welding torch drive mechanism 11, a weld monitoring mechanism 12, a welding line tracking control mechanism 34, and a welding condition control mechanism 35, and the welding target portion at the tip of the gas turbine rotor blade 1 has a predetermined shape. 1 shows a welding apparatus including a mechanism 36 for determining the existence and a control mechanism 37 for performing welding after correcting an error from a predetermined shape.
[0041]
Here, whether the welding target part at the tip of the moving blade has a predetermined shape is determined by, for example, inputting an assumed welding target part processed into a predetermined shape in advance and actually monitoring the welding of the moving blade The determination is made by comparing the target portion with the image-processed data. When an error occurs, welding is performed by correcting the movement trajectory of the welding torch according to the monitored welding target portion.
[0042]
【The invention's effect】
As described above, according to the present invention, it is possible to easily perform automatic welding with controlled heat input to the tip of the gas turbine rotor blade, and to provide a sound build-up weld that does not cause welding defects. Can be formed.
[Brief description of the drawings]
FIG. 1 is a side view showing a repaired state of a gas turbine rotor blade of the present invention.
FIG. 2 is a diagram illustrating a machining mode of a deteriorated portion at the tip of a gas turbine rotor blade.
FIG. 3 is a top view of a moving blade whose tip is processed into a certain shape and surface-finished.
FIG. 4 is a diagram illustrating a state in which overlay welding of a moving blade is automatically performed according to a weld line.
FIG. 5 is a view showing a repairing method in which build-up welding is performed with a moving blade installed on a turbine disk.
FIG. 6 is a diagram in which a turbine disk is rotated to set a torch on a moving blade to be repaired next.
FIG. 7 is a diagram showing a build-up weld when the edge and center of the weld surface are finished to the same height.
FIG. 8 is a diagram showing overlay welding when finishing is performed so that the edge of the weld surface is higher than the center.
FIG. 9 is a side view of a moving blade in which a repaired part is finished into the original shape of a gas turbine moving blade after overlay welding.
FIG. 10 is a side view of a rotor blade tip portion that has been recoated with a ceramic layer after overlay welding.
FIG. 11 is a construction diagram in which overlay welding is performed while heating the vicinity of the tip of a moving blade.
FIG. 12 is a construction diagram in which overlay welding is performed while cooling the vicinity of the tip of a moving blade.
FIG. 13 is a view of a deteriorated portion having various shapes at the blade tip.
FIG. 14 is a diagram illustrating repair of a locally deteriorated portion at the tip of a moving blade.
FIG. 15 is a view showing a repair welding apparatus for a gas turbine blade.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Gas turbine rotor blade, 2 ... Deterioration part of blade tip, 3 ... Deterioration part cut | disconnected or ground, 4 ... Surface to be welded processed to fixed shape, 5 ... Overlay welding part, 6 ... Welding torch , 7 ... welding electrode, 8 ... arc, 9 ... turbine disk, 10 ... crane, 11 ... drive mechanism, 12 ... monitoring monitor camera, 13 ... edge of finished surface, 14 ... center of finished surface, 15 ... heat influence 16, hot cracks in the heat affected zone, 17 repair parts finished to the original shape after overlay welding, 18 coating layer, 19 spacer, 20 drive controller, 21 heating mechanism, 22 DESCRIPTION OF SYMBOLS ... Electric wire, 23 ... Power supply for heating, 24 ... Hook mechanism, 25 ... Water-cooled Cu plate, 26 ... Cooling water injection port, 27 ... Cooling water discharge port, 28 ... Cooling water, 29 ... Welding power source, 30 ... Feed material supply Mechanism 31 ... Filler material 32 ... Preheating or cooling mechanism 33 ... Control mechanism for preheating condition or cooling condition, 34 ... Control mechanism for welding line, 35 ... Control mechanism for welding condition, 36 ... Judgment mechanism for welded part shape, 37 ... Error correction control mechanism for profile welding, 38 ... Shield gas cylinder, 39 ... gas pipe.

Claims (10)

In the repairing method of the gas turbine blade, which is subjected to overlay welding on the damaged part of the gas turbine blade, and the blade shape is restored,
Wherein the respective gas turbine blade to cut into the same predetermined shape, then repairing method of cutting the gas turbine blade, characterized in that it has to apply the overlay welding portions having a damaged portion. In the repair method of the gas turbine blade, which is subjected to overlay welding on the damaged tip of the gas turbine blade, and the blade shape is restored,
Before the overlay welding, loss respectively of each wing having a wound distal end section, cut or ground to the same predetermined shape parallel to the moving blade of the original tip surface, the meat then cut or ground portions A repair method for gas turbine blades, characterized by performing prime welding. In the repair method of the gas turbine blade, which is subjected to overlay welding on the damaged tip of the gas turbine blade, and the blade shape is restored,
Before the overlay welding, that each rotor blade damage tip cut or ground to the same predetermined shape having a constant inclination from the tip end surface of each source, and to subsequently apply the overlay welding A gas turbine blade repair method that is characterized. In the repair method of the gas turbine blade, which is subjected to overlay welding on the damaged tip of the gas turbine blade, and the blade shape is restored,
Before the welding, after the cutting cut or Ken each blade damage tip respectively same predetermined shape, welding torch welding conditions at the copying position and each part of the weld at the welded portion of the surface in advance A gas turbine blade repair method characterized in that overlay welding is performed by inputting to a drive mechanism and a welding condition control mechanism.   The method for repairing a gas turbine blade according to claim 1, 2, 3 or 4, wherein the build-up welding is performed while the blade is incorporated in a turbine disk. In the repair method of the gas turbine blade, which is subjected to overlay welding on the damaged tip of the gas turbine blade, and the blade shape is restored,
Before the welding work, after cutting the damaged tip of each rotor blade into the same predetermined shape, finish processing so that the edge of the surface is higher than the central part, and then overlay welding A gas turbine blade repair method characterized by that. Subjecting said overlay welding to larger than the shape of the gas turbine blade, after overlay welding, to any one of the repair part from claim 1 which is adapted to finishing to its original shape when the rotor blade manufacturing 6 The gas turbine rotor blade repair method described. Depending on the cut or ground to a shape of the surface in front of the overlay welding, any one of claims 1 to 7 which is adapted to set the pre-heating condition or cooling condition before and after overlay welding or during construction gas turbine blade method repairing described. In the gas turbine blade in which build-up welding is applied to the damaged tip of the gas turbine blade and the blade shape is restored,
The damage tip of the overlay weld part shape or size of the moving blade of the size or moving blade stages or blades incorporated in the turbine disc material or blade before welding serviced environment or blade before welding A turbine rotor blade characterized in that it is determined in the same manner according to the years of service. Welding torch, welding power source, filler material supply mechanism, gas shield mechanism, moving blade preheater or cooling mechanism, preheating condition or cooling condition control mechanism, welding torch drive mechanism, welded mechanism, welding line leveling control In a gas turbine blade repair device that has a mechanism and a welding condition control mechanism , cuts the damaged portion of each gas turbine blade in the same way, and then performs overlay welding to restore the blade shape,
The apparatus is provided with a mechanism for determining that the welding target portion at the tip of the gas turbine rotor blade has a predetermined shape, and a control mechanism for performing overlay welding by correcting an error from the predetermined shape. Repair equipment for gas turbine blades.

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