EP1868766A1

EP1868766A1 - Method for repairing or renewing cooling holes of a coated component of a gas turbine

Info

Publication number: EP1868766A1
Application number: EP06725381A
Authority: EP
Inventors: John William Fernihough; Matthias Hoebel; Maxim Konter
Original assignee: Alstom Technology AG
Current assignee: General Electric Technology GmbH
Priority date: 2005-04-07
Filing date: 2006-03-29
Publication date: 2007-12-26
Also published as: US20080085395A1; WO2006106061A1; CA2602628A1

Abstract

The present invention relates to a method for repairing or renewing cooling holes of a coated component of a gas turbine, having the following steps: - removal of an old coating from an outer side (2) of the component (1). The cooling hole (5) has an old cross section after removal of the old coating in a longitudinal section (11), which old cross section is greater than a setpoint cross section which the cooling hole (5) has in an original new state of the finished component in this longitudinal section. - application of a new coating (3', 4') to the component (1) at least in the longitudinal section (11) of the cooling hole (5), in such a way that the cooling hole has an intermediate cross section (16) in the longitudinal section (11), which intermediate cross section (16) is smaller than the setpoint cross section (6), - partial removal of the new coating (3', 4') within the cooling hole (5), in such a way that the cooling hole (5) has a new cross section (18) in the longitudinal section (11), which new cross section (18) is approximately as large as the setpoint cross section (6).

Description

METHOD FOR REPAIRING OR RENEWING COIL HOLES OF A COATED

COMPONENT OF A GAS TURBINE

Technical area

The present invention relates to a method for repairing or renewing cooling holes of a coated component of a gas turbine.

Components of gas turbines, such as blades, vanes, heat shield elements, or other cooled parts, often contain voids which serve to distribute cooling air to a plurality of cooling holes in a wall of the respective component. These cooling holes lead the cooling air to an outer surface exposed to the hot working gases of the gas turbine. Such components are usually provided with an oxidation and / or corrosion protection layer, which may also be referred to as a base coat. In addition, the components may also be provided with a heat protection layer which serves to thermally insulate the component. During operation of the gas turbine, degradation of the coating or coatings often occurs before the coated component itself is attacked. As a result, at least once during the lifetime of the respective component, the base coat and, if necessary, the heat protection layer must be removed and reapplied. When applying a new coating, however, the existing cooling holes are problematic. While in the manufacture of a new component, the cooling holes are introduced after the application of the coating in the component, the cooling holes are already present when re-applying a new coating. When applying the new coating, the coating material can penetrate into the cooling holes and change their cross sections. The components of modern gas turbines can contain hundreds of such cooling holes whose cross sections or their cross-sectional profiles are within very narrow tolerance limits. The upper tolerance limit for the cooling hole cross sections should avoid the injection of unnecessary cooling air, which would drastically reduce the efficiency of the gas turbine and its power output. The lower tolerance limit for the cooling hole cross-sections should prevent overheating of the respective component, which would lead to a significant reduction in the lifetime of the respective component.

State of the art

To repair or renew the cooling holes, it is basically possible to weld or solder the cooling holes after removing the old coating. Then the new coating can be applied. Then the cooling holes can be re-drilled. The problem with this is that the welding methods or soldering methods used for this purpose introduce weak points into the material of the component. Furthermore, a common drilling method is associated with positional tolerances, so that when re-drilling the cooling holes positional deviations can occur to the old cooling holes. This has the consequence that welding material or solder material remains in the material of the component, so that the component with the said Weak points is put into operation, which affects the mechanical strength of the component.

From US Pat. No. 5,702,288 it is known to apply the new coating after removing the old coating without first soldering or welding the cooling holes. As a result, the new coating penetrates into the cooling holes more or less and narrows their cross-section. Subsequently, an abrasive abrasive slurry is introduced under high pressure into the cavity of the component and expelled through the cooling holes. In this way, the coating can be ground within the cooling holes. However, in this approach, internal portions of the component, such as cooling fins or inserts, as well as uncoated portions of the cooling holes are also exposed to the abrasive slurry's abrasive action. Furthermore, such a method is unsuitable for vanes incorporating a cooling air distribution insert, since such a diverter insert would have to be removed first, but this would be time consuming and costly. Furthermore, it is basically possible to press the grinding slurry from the outside through the cooling holes in the cavity of the component. Basically, however, the same difficulties occur here, and in addition, in addition, the coating of the component is exposed to the abrasive effect of the abrasive slurry.

From US Pat. No. 4,743,462 it is known to introduce volatile plugs into the cooling holes before the application of the new coating, which at least partially evaporate during the coating process. The evaporation of the stopper prevents clogging of the cooling holes by the coating material. The disadvantage here, however, that the plug must be introduced individually into the cooling holes. For large components of stationary gas turbines, which can have several hundred cooling holes, inserting the plugs individually into each cooling hole is extremely time consuming. About that In addition, different components may have different types of cooling holes, each requiring specially adapted plugs.

From US Pat. No. 5,985,122, US Pat. No. 6,258,226 and US Pat. No. 5,565,035 it is known to simultaneously block a plurality of cooling holes before attaching the new coating with the aid of a corresponding tool. However, these tools are not suitable for thermal spray coating processes.

From US 5,800,695 it is known to press a cover through the cavity in the cooling holes from the inside until the covering reaches the outer surface of the respective component. Subsequently, an electrolytic platinum coating can be carried out. Since the covering means is made of plastic and accordingly is not electrically conductive, the platinum can not accumulate on the covering means in the region of the cooling holes.

Another method is known from US 4,743,462, which works with a covering agent, which evaporates already at temperatures which are below the temperatures occurring during application of the coating. For example, it is necessary for certain oxidation and / or corrosion protective layers that they form a diffusion bond with the material of the component. In order to achieve such a diffusion bonding, a high-temperature treatment is required, which runs, for example, in a temperature range of 1000 ⁰ C to 1150 ⁰ C. At these high temperatures, the covering agent volatilizes in any case. In order to be able to subsequently attach a heat protection layer, the covering agent would have to be re-introduced.

From US 6,004,620 it is known to remove the penetrated into the cooling holes areas of the coating using a high-pressure water jet. However, the device with the help of the high pressure water jet in the individual cooling holes can be introduced, too unwieldy, so as to clean, for example, the cooling holes of a turbine blade from the inside. Other methods using a high pressure water jet are known from US 2001/001680 and US 2001/006707.

Furthermore, it is known from US Pat. No. 6,210,488 to detach a heat protection layer which has deposited in the interior of the cooling holes with the aid of a corrosive solution, it being possible optionally to provide an ultrasound treatment. However, such an approach is only suitable for the complete removal of the heat protection layer from the entire component. Covering the heat protection layer of the entire component apart from the individual cooling holes is impractical.

It is known from US Pat. No. 5,216,808 to remove the unwanted heat protection coating inside the cooling holes with the aid of a pulsed ultraviolet laser. Although the wavelength of the UV laser is suitable for removing conventional heat protection layers, for example of zirconium oxide, conventional oxidation and / or corrosion protection layers can not be removed regularly or can only be removed unreliably.

Another method that uses a covering agent is known from US 6,265,022. The covering agent used there is based on a polymer and can be used for all those coating processes in which the temperatures do not exceed a temperature causing the destruction of the covering. In contrast to the abovementioned covering method, in this method the covering means is introduced in such a way that it projects beyond the outer surface of the component at an outlet opening of the respective cooling hole. Furthermore, it is known from US Pat. No. 6,042,879 to initially expand the cooling holes before applying the new coating, such that the subsequent coating, due to the penetration of the coating material into the cooling holes, reduces the cross section of the cooling holes more or less to a desired nominal cross section. That such a procedure is subject to extreme tolerances, is obvious.

Presentation of the invention

This is where the present invention begins. The invention, as characterized in the claims, deals with the problem of providing for a method of the type mentioned in an improved embodiment, which is characterized in particular by an increased lifetime of the repaired or renewed th th cooling hole.

According to the invention, this problem is solved by the subject matters of the independent claims. Advantageous embodiments are the subject of the dependent claims.

The invention is based on the general idea to carry out the repair or renewal of the cooling holes so that the cooling holes then have substantially the same cross-sections or substantially the same cross-sectional characteristics, as in the original unused state of the finished component. At the same time, however, a longitudinal section of the respective cooling hole, which extends to the outside of the component, should also be provided with the new coating. The restoration of the original geometry of the cooling hole ensures that the cooling hole can fulfill its intended function optimally. At the same time, this reduces the risk that hot working gas can penetrate into the cooling hole. Except- The effect of the new coating extending into the longitudinal section of the cooling hole is to intensively protect the material of the component from the aggressive hot working gases, if they should nevertheless penetrate into the respective cooling hole. In this way, corrosion of the cooling hole and thus a cross-sectional widening can be avoided. A cooling hole cross-section which widens due to corrosion during operation of the gas turbine facilitates the penetration of the aggressive working gas into the cooling hole and thereby increases the corrosive effect, which leads to an increased further cross-sectional widening.

With the aid of the repair process of the present invention, the repaired cooling holes have at least the same, if not better, resistance to the aggressive hot working gases of the gas turbine.

For realizing the invention, on the one hand, the removal of the at least one old coating is carried out such that subsequently the borehole has an old cross-section or old cross-sectional profile at least in said longitudinal section whose opening width is greater than a SoII cross-section or desired cross-sectional profile that the borehole has when new with unused component. Subsequently, the coating with the at least one new coating is selectively carried out so that this longitudinal section of the cooling hole has an intermediate cross-section or intermediate cross-sectional profile whose opening width is smaller than in SoII cross-section or desired cross-sectional profile. In this way, it is ensured that during the subsequent "drilling" of the individual cooling holes the original desired cross-section or desired cross-sectional profile can again be produced In the invention, this "drilling" is realized by a partial removal of the new coating within the cooling hole. such that the cooling hole subsequently in the longitudinal section and in particular in the new Coating penetrating hole area has a new cross-section or new cross-sectional profile, which substantially corresponds to the desired cross-section and the desired cross-sectional profile.

The partial removal of the new coating is suitably carried out with a suitable laser method. Laser ablation methods or laser milling and / or drilling methods are particularly suitable for this purpose.

For the new coating, which extends into the longitudinal section of the cooling hole, it is expedient to use an oxidation and / or corrosion protection layer.

The problem underlying the invention is accordingly also solved by a component of a gas turbine, which has at least one cooling hole, which in an adjacent to the outside of the component

The longitudinal region is likewise coated, with the cooling hole otherwise having a desired nominal cross-section or a desired cross-sectional profile along its entire length.

Other important features and advantages of the present invention will become apparent from the dependent claims, from the drawings and from the associated figure description with reference to the drawings.

Brief description of the drawings

Preferred embodiments of the invention are illustrated in the drawings and will be described in more detail in the following description, wherein like reference numerals refer to the same or similar or functionally identical components. Show, in each case schematically,

1 A to 1 E each show a cross section through a component in the region of a cooling hole at different states (A to E),

2A to 2E are views as in FIGS. 1A to 1E, but in another embodiment of the cooling hole,

3A to 3E are views as in FIGS. 1 A to 1 E, but in a further embodiment of the cooling hole.

Ways to carry out the invention

1A, 2A and 3A each show a component 1 of a gas turbine, not shown otherwise, which is provided on its outer side 2 with at least one coating. In the preferred embodiment shown here, the component 1 is provided in each case with two coatings, namely with a first coating 3 and a second coating 4. While the first coating 3 is applied to the component 1, the second coating 4 is applied to the first coating 3. In another embodiment, the component 1 may also have only a single coating or even more than two coatings. The inventive method is then applicable accordingly.

The respective sections of the component 1 shown are provided with a cooling hole 5. It is clear that the component 1 can basically also have more than one such cooling hole 5. The component 1 is, for example, a blade or a vane or a heat shield element or any other cooled component. Each cooling hole 5 leads from a cavity, not shown, in the interior of the component 1 to the outside 2. In addition, the respective cooling hole 5 is extended through the coatings 3, 4 through to an outer skin 10 of the coated component 1.

The first coating 3 is expediently an oxidation and / or corrosion protection layer. Such an oxidation and / or corrosion protection layer can be formed, for example, by a metal coating, in particular from MCrAlY. M is at least one member of the following group: iron (Fe), copper (Cu), nickel (Ni) and cobalt (Co) and combinations thereof. Particularly noteworthy in this connection are NiCrAlY, CoCrAlY, NiCoCrAlY. In contrast, the second coating 4 is preferably a heat protection layer. Such a heat protection layer can be achieved for example by a ceramic coating, which consists for example of zirconium oxide. The oxidation and / or corrosion protection layer, that is to say the first coating 3, can have, for example, a layer thickness of 150 μm to 600 μm. In contrast, the heat protection layer, that is to say the second coating 4, may preferably have a layer thickness of approximately 200 μm to 500 μm.

In FIGS. 1A, 2A and 3A, the component 1 is in an original new state which it has after its coating with the layers 3 and 4 and after the introduction of the cooling holes 5. In this new state, each cooling hole 5 has a desired desired cross-section or a desired desired cross-sectional profile in the longitudinal direction of the cooling hole 5. The SoI I cross-section is denoted in Fig. 1A, 2A and 3A with 6, while the target Cross-sectional course is denoted by 7. The embodiments of FIGS. 1, 2 and 3 differ by the design of the cooling holes 5. In the new state, the cooling hole 5 has in the embodiments of FIGS. 1A and 2A in its longitudinal direction a constant desired cross section 6. The nominal cross section. 6 may be circular, for example. In contrast, in the embodiment according to FIG. 3A, the cooling hole 5 is provided with a desired cross-sectional profile 7, which widens toward an outlet opening 8 of the cooling hole 5. The outlet opening 8 is located at the outflow end of the cooling hole 5 extending inside the component 1 and is thus at the level of the outside 2 of the component 1. In the coated component 1, however, the cooling hole 5 is extended through the coatings 3, 4, whereby the outlet opening shifts to the outer skin 10 of the coated component 1, that is, to the outside of the second coating 4. This outer outlet opening is referred to below with 8 '.

For example, an aerodynamically shaped outlet region 9 can thereby be achieved within the component 1 or within the coatings 3, 4. An aerodynamically shaped outlet region 9 improves, for example, the formation of a cooling film which, during operation of the gas turbine, bears against the outer skin 10 of the coated component 1 and thereby improves the cooling effect or the thermal insulation of the coated component 1. Other aerodynamically designed exit regions 9 are known, for example, from US Pat. No. 6,183,199, US Pat. No. 4,197,443 and EP 0 228 338, the contents of which are hereby included by express reference in the disclosure of the present invention.

The embodiments of FIGS. 2A and 3A also differ from those of FIG. 1A in that the longitudinal direction of the cooling holes 5 in the embodiments of FIGS. 2A and 3A is inclined relative to a normal direction of the outside 2, while in the embodiment according to FIGS FIG. 1A runs parallel to the normal direction. In the embodiment of FIG. 2A, the longitudinal direction of the cooling hole 5, for example, an angle of attack of about 45 °, while the angle of attack in the embodiment of FIG. 3A is only about 30 °, however, by the widening discharge area 9 to about 60 ° increases.

The intended for the new condition of the component 1 target cross-section 6 and the target cross-sectional profile 7 is designed with regard to an optimal cooling effect at the same time optimized performance and optimized efficiency of the gas turbine. The nominal cross-section 6 or the desired cross-sectional profile 7 is manufactured within relatively narrow tolerance limits.

During operation of the gas turbine, the coatings 3, 4 wear out, in particular in the area of the cooling holes 5. FIGS. 1 B, 2 B and 3 B each show a state at a time when a repair or renewal of the Cooling holes 5 is advisable. This point in time is located, for example, approximately in the middle of the lifetime provided for the gas turbine or for its component 1. It can be clearly seen from FIGS. 1B, 2B and 3B that not only the outer second protective layer 4 but also the inner first protective layer 3 as well as a perforated wall 15 laterally enclosing the cooling hole 5 are removed at least in a longitudinal section 11 of the cooling hole 5 , This longitudinal section 11 adjoins the outer side 2 of the component 1 and is characterized in the figures in each case by a curly bracket.

Due to the removal of material in the coatings 3, 4 and within the component 1 in the longitudinal section 11, the cooling hole 5 receives an enlarged cross-section e 'or an expanded cross-sectional profile 7' at least in the longitudinal section 11 and within the coatings 3, 4. The original contours of the cooling hole 5 and the coatings 3, 4, ie the setpoint Cross-section e or the desired cross-sectional profile 7 is indicated in FIGS. 1 B, 2B and 3 B in each case by a broken line.

In order to repair or renew the cooling holes 5 shown in FIGS. 1B, 2B and 3B, the method according to the invention is carried out, which is explained in more detail below:

In a first method step, the old coatings 3, 4 are removed from the outside 2 of the component 1, namely at least in a hole area 12, which encloses the cooling hole 5. In the figures, this hole region 12 extends in each case over the entire section of the component 1 shown. In FIGS. 1C, 2C and 3C, the original contour of the cooling hole 5 and of the coatings 3, 4 is indicated by a broken line.

The removal of the old coatings 3, 4 can be carried out in a conventional manner, for example by means of an acid or by means of a corrosive solution. After the removal of the old coatings 3, 4, the cooling hole 5 in the longitudinal section 11 has an old cross-section 13 or an old cross-sectional profile 14. This old cross-section 13 or the Alt cross-sectional profile 14 may coincide with the widened cross-section 6 'or cross-sectional profile 7' of the state of use shown in FIGS. 1B, 2B and 3B. In principle, however, it is possible that the process for removing the old coatings 3, 4 leads to a widening of the cross-section or the cross-sectional profile, which is the case, for example, if the removal of the old coatings 3, 4 simultaneously corrosion or oxidation deposits at the cooling hole 5 laterally delimiting hole wall 15 are also removed. In the latter case, the old cross-section 13 or the old cross-sectional profile 14 is then determined by the process of removing the old coatings 3, 4. In any case, the old Cross section 13 larger than the desired cross-section 6. Also, the old cross-sectional profile 14 is wider than the desired cross-sectional profile. 7

In a second step of the method according to the invention, at least one new coating is applied to the component 1. In the present example, two coatings are again applied, namely a new first coating 3 ', which is applied directly to the component 1, and a new second coating 4', which is applied to the new first coating 3 '. The new first coating 3 'expediently corresponds to the original (old) first coating 3. In a corresponding manner, the new second coating 4' expediently corresponds to the original (old) second coating 4. It is clear that the new coatings 3 'and 4 Consider any technological advances in coating technology that may have occurred since the time of the original new state of FIGS. 1A, 2A and 3A and the time of repair.

The application of the new coatings 3 ', 4' can be carried out, for example, by means of a high-temperature spray method, for example plasma spraying. For the application of the new coatings 3 ', 4', it can also be expedient to carry out a high-temperature treatment between the application of the new first coating 3 'and the application of the new second coating 4', for example a diffusion bond between the materials of the new first Coat 3 'and the component 1 produce.

According to FIGS. 1D, 2D and 3D, the first new coating 3 'is applied in such a way that it extends into the cooling hole 5, at least in the longitudinal section 11. In addition, this coating process is carried out in this way. that in the longitudinal section 11 and within the new coatings 3 ', 4', ie in the hole region 12, an intermediate cross-section 16 or an intermediate cross-sectional profile 17 results, which is smaller than the original desired cross-section 6 or desired cross-sectional profile 7. The new second coating 4 'can thereby also extend into the cooling hole 5 and in addition to the new first coating 3 'build, whereby the intermediate cross-section 16 and the intermediate cross-sectional profile 17 is additionally narrowed.

As shown in FIG. 2D, when the new coatings 3 ', 4' are applied, the intermediate cross-section 16 may shrink to zero at some points, ie, the new coating 3 ', 4' completely closes the cooling hole 5 ,

After the new coatings 3 ', 4' have been produced, a third step is followed by a partial removal of the new coatings 3 ', 4' from the perforated wall 15 in a third step. This partial removal of the new coatings 3 ', 4 'is thereby carried out so that the cooling hole 5 then in accordance with FIGS. 1 E, 2E and 3E at least in the longitudinal section 11 and in the hole area 12, ie within the new coatings 3', 4 'a new cross-section 18 or a Neu-

Cross-sectional profile 19 has. The partial removal of the new coatings 3 ', 4' is specifically carried out so that the new cross-section 18 and the new cross-sectional profile 19 is about the same size as the desired cross-section 6 and the desired cross-sectional profile 7. Since the Alt Cross section 13 or the AIt- cross-sectional profile 14 has a larger opening width than the desired cross-section 6 and the target cross-sectional profile 7, the component 1 in the longitudinal section 11 of the cooling hole 5 is provided with the material of the new first coating 3 '. Accordingly, along the longitudinal section 11, the hole wall 15 is formed by the region of the new first coating 3 'protruding into the cooling hole 5. Since the cooling hole 5 after its repair or after its renewal has substantially the same dimension and shape as in the new state, the originally intended cooling performance can thus be achieved again during operation of the gas turbine. At the same time a high efficiency and a high power output of the gas turbine are again achieved as in new condition. It is particularly advantageous that the perforated wall 15 is coated at least in the area of the longitudinal section 11 with the material of the new first coating 3 ', whereby the perforated wall 15 is protected against corrosion, which occurs when the aggressive hot working gases enter the cooling hole 5 can occur. The durability of the repaired cooling hole 5 is thus at least equal to or even greater than the lifetime of the original cooling hole 5 in the new state of the component 1.

FIGS. 1E, 2E, 3E thus show a component 1 with repaired cooling hole 5, which differs from the original component 1 in the new state in that the new first coating 3 'extends into the longitudinal region 11.

In order to partially remove the new coatings 3 ', 4' in the region of the cooling hole 5, a laser method is preferably used. In this case, for example, a laser milling and / or drilling process comes into question. Such a laser milling and / or drilling method is distinguished, for example, by laser pulse energies which lie in a range from 1 J to 60 J. Pulse times in the range of 0.1 ms to 20 ms occur.

Alternatively, it is also possible to use a laser ablation method which is characterized in particular by pulse times which lie in the range from approximately 10 ns to 1000 ns. This corresponds to pulse frequencies in the range of about 1 kHz to 100 kHz. In the laser ablation process, the energy density is individual pulse considerably larger than during laser milling or laser drilling. At the same time, less material volume is affected due to the considerably smaller pulse energy (1 mJ to 5OmJ). In this way, in particular a re-solidification of the melted areas of the new coating 3 ', 4' to be removed can be avoided. Accordingly, the laser ablation process leads to an extremely clean new cross-sectional profile 19.

The method according to the invention can, of course, also be carried out in the case of a component 1 which has a plurality of cooling holes 5, wherein it is then possible in particular to carry out the method at several cooling holes 5 at the same time or to offset one another with respect to the individual method steps.

LIST OF REFERENCE NUMBERS

1 component

2 outside of 1 3 (old) first coating

3 'new first coating

4 (old) second coating 4 'new second coating

5 cooling hole 6 nominal cross section

6 'cross section

7 Specified cross section T Cross section

8 outlet at 1 8 'outlet at 10

9 exit area

10 outer skin

11 longitudinal section of 5

12 hole area 13 old cross section

14 Old cross-sectional course

15 hole wall

16 intermediate cross section

17 Intermediate cross section 18 New cross section

19 New cross-sectional course

Claims

claims

1. A method for repairing or renewing cooling holes (5) of a coated component (1) of a gas turbine, comprising the following steps:

Removing at least one old coating (3, 4) from an outer side (2) of the component (1) at least in a hole region (12) enclosing the cooling hole (5), the cooling hole (5) at least after removing the at least one old one Coating (3, 4) at least in a longitudinal section (11) adjoining the outside (2) of the component (1)

Old cross-section (13) which is greater than a desired cross section (6), the cooling hole (5) in an original new state of the finished component (1) in this longitudinal section (11),

- Attaching at least one new coating (3 ', 4') on the component (1) at least in the hole region (12) and at least in the longitudinal section (11) of the

Cooling hole (5), such that the cooling hole (5) at least in the longitudinal section (11) and / or in the hole region (12) has an intermediate cross section (16) which is smaller than the desired cross section (6),

- Partial removal of the at least one new coating (3 ', 4') within the cooling hole (5), such that the cooling hole (5) at least in the longitudinal section (11) and / or in the hole region (12) has a new cross-section (18) which is approximately the same size as the desired cross-section (6).

2. Method according to claim 1, characterized in that for the partial removal of the at least one new coating (3 ', 4') a laser method is used.

3. Method according to claim 2, characterized in that

that the laser method is designed as a laser milling and / or drilling method, and / or

- That the laser milling and / or drilling process with laser pulse energies in the range of 1 J to 60 J or with pulse times in the range of 0.1 ms to 20 ms or with pulse frequencies in the range of 1 Hz to 50 Hz works, and / or

- That the laser method is designed as a laser ablation method, and / or

- That the laser ablation method operates with laser pulse energies in the range of 1 mJ to 50 mJ and / or with pulse times in the range of 10 ns to 1,000 ns and / or with pulse frequencies in the range of 1 kHz to 100 kHz.

4. The method according to any one of claims 1 to 3, d ad h e c h n e n c i n e,

- That when removing the at least one old coating applied to the component old oxidation and / or corrosion protection layer (3) and on the oxidation and / or corrosion protection layer (3) applied old heat protection layer (4) are removed, and / or

- That when attaching the at least one new coating, a new oxidation and / or corrosion protection layer (3 ') in the hole area (12) and in the longitudinal section (11) is applied, and / or

- that after attaching the new oxidation and / or corrosion protection layer 3 ', a new heat protection layer 4' at least in the hole area (12) on the oxidation and / or corrosion protection layer 3 'is applied, and / or

- That as a new oxidation and / or corrosion protection layer (3 '), a metal coating is used, and / or - that as a new oxidation and / or corrosion protection layer (3 ') an MCr-AlY coating is used, wherein M is at least one member from the following group: iron, copper, nickel, cobalt or combinations thereof, and / or - that as new heat protection layer (4 ') is used a ceramic coating, and / or

- That as a new heat protection layer (4 ') a zirconium oxide coating is used, and / or

- That the new oxidation and / or corrosion protection layer (3 ') is applied with a layer thickness of about 150 microns to 600 microns, and / or

- That the new heat protection layer (4 ') is applied with a layer thickness of about 200 microns to 500 microns.

5. The method according to any one of claims 1 to 4, d ad h e c e n e c i n e n,

that the method for repairing or renewing such cooling holes (5) is used, which in the component (1) and / or in the at least one coating (3, 4) has a constant nominal cross section (6) along its length, and / or - the method is used for repairing or replacing such cooling holes (5), which have a longitudinal direction inclined to a normal to the outside (2) of the component (1), and / or

that the method for repairing or renewing such cooling holes (5) is used, which in the component (1) and / or in the at least one coating (3, 4) has an aerodynamically shaped outlet region (9) with a varying nominal Have cross section (6), and / or

that the method for repairing or renewing such cooling holes (5) is used, which in the component (1) and / or in the at least one coating (3, 4) has an outlet opening (8, 8 '). have a desired set cross-section (6).

6. The method according to any one of claims 1 to 5, d ad h e c h n e n c i n e,

in that the cooling hole (5) after removal of the at least one old coating (3, 4) in the longitudinal section (11) in the longitudinal direction of the cooling hole (5) has an old cross-sectional profile (14) whose individual altitudinal cross sections (14) 13) are larger than the associated desired cross-sections (6) of a desired cross-sectional profile (7) in this longitudinal section (11), and / or

in that - after the at least one new coating (3 ', 4') has been applied in the longitudinal section (11) and / or in the hole region (12) in the longitudinal direction of the cooling hole (5), the cooling hole (5) has an intermediate cross-sectional profile (FIG. 17), whose individual intermediate cross-sections (16) are smaller than the associated desired cross-sections (6) of a desired cross-sectional profile (7), and / or - that the cooling hole (5) after the partial removal of the at least one new coating (3 ', 4') in the longitudinal section (11) and / or in the hole region (12) in the longitudinal direction of the cooling hole (5) has a new cross-sectional profile (19) whose individual Neu cross-sections (18) are about the same size as the associated desired cross-sections (6) of a desired cross-sectional profile (7).

7. Method according to one of claims 1 to 6, characterized in that the method in a component (1) having a plurality of cooling holes (5) at a plurality of cooling holes (5) simultaneously or with respect to individual process steps is performed offset in time.

8. Coated component (1) of a gas turbine, having at least one cooling hole (5), which in a longitudinal region (11) adjoining an outer side (2) of the component (1) and / or in a perforation hole enclosing the cooling hole (5). region (12) has a nominal cross-section (6) or in its longitudinal direction a nominal Has cross-sectional profile (7), the cooling hole (5) in an original new state of the finished component (1), wherein a coating (3 ') of the component (1) at least extends into the longitudinal region (11).