Method for repairing a gas turbine blade
By brazing pre-sintered preforms onto gas turbine blades and filling them with peelable or thermally decomposable fillers, the problems of oxidation and pore blockage in existing repair methods are solved, achieving efficient repair and performance improvement.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SIEMENS GAS TURBINE COMPONENTS (JIANGSU) CO LTD
- Filing Date
- 2026-04-16
- Publication Date
- 2026-06-16
Smart Images
Figure CN122210352A_ABST
Abstract
Description
Technical Field
[0001] This disclosure pertains to the field of gas turbines, and specifically relates to a method for repairing gas turbine blades. Background Technology
[0002] It is known that corrosion and impact from combustion gases can cause wear and even damage to gas turbine blades. For example, as blades wear down, their wall thickness may gradually decrease. When the wall thickness is less than or equal to a threshold, blade repair is necessary. Conventional repair methods use fusion welding (such as arc welding) to increase the blade wall thickness, but this can lead to blade oxidation or even burn-through, especially when the blade wall thickness is small. Furthermore, fusion welding can overheat the blade, causing degradation of the strengthening phases and affecting blade performance. Moreover, existing repair methods are unsuitable for repairing sections of the blade near boreholes because molten material can flow into the boreholes during the repair process, causing blockage. Summary of the Invention
[0003] To overcome at least one of the technical problems described in the background section, this disclosure provides a method for repairing a gas turbine blade, comprising: providing a pre-sintered preform; positioning the pre-sintered preform onto a damaged portion of the gas turbine blade, the damaged portion being adjacent to a bore structure of the gas turbine blade; providing a filler; filling the bore structure with the filler to seal the bore structure; and after the positioning and the filling, heat-treating the gas turbine blade and the pre-sintered preform such that the pre-sintered preform is brazed to the gas turbine blade.
[0004] In this disclosure, by brazing the pre-sintered preform to the gas turbine blade, the strengthening phase of the gas turbine blade can be prevented from deteriorating due to overheating, resulting in a repaired gas turbine blade with good performance. Furthermore, by filling the pore structure with filler, the filler can prevent the pre-sintered preform from flowing into the pore structure, thereby avoiding blockage of the pore structure by the pre-sintered preform, making the method applicable to damaged portions adjacent to the pore structure.
[0005] Furthermore, the filler is configured to cure during the heat treatment, and the method further includes removing the filler from the pore structure after the brazing.
[0006] In this disclosure, by curing the filler during heat treatment, the filler can be easily removed from the pore structure after brazing, thereby improving repair efficiency.
[0007] Furthermore, the packing is configured to decompose into gas during the heat treatment.
[0008] In this disclosure, by decomposing the filler into gas during heat treatment, the step of removing the filler from the pore structure can be eliminated, thereby improving the repair efficiency.
[0009] Furthermore, the pre-sintered preform comprises a high-temperature alloy.
[0010] In this disclosure, by including a high-temperature alloy in the pre-sintered preform, the pre-sintered preform and the gas turbine blade can be close to or even the same in terms of solidus temperature and liquidus temperature, thereby ensuring that the repaired gas turbine blade has good performance.
[0011] Furthermore, the method further includes cleaning the damaged portion before positioning.
[0012] In this disclosure, by cleaning the damaged part, the oxide layer at the damaged part can be removed and the damaged part can be made flat, thereby improving the brazing quality.
[0013] Furthermore, the heat treatment is performed under a protective atmosphere or a vacuum atmosphere.
[0014] In this disclosure, by carrying out heat treatment in a protective atmosphere or a vacuum atmosphere, oxidation of the gas turbine blades during the heat treatment process can be avoided, resulting in the repaired gas turbine blades having good performance.
[0015] Furthermore, the temperature of the heat treatment is 1000°C to 1400°C, and the duration of the heat treatment is 40 min to 80 min.
[0016] In this disclosure, by setting the heat treatment temperature to 1000°C to 1400°C and the heat treatment duration to 40 min to 80 min, the connection strength between the gas turbine blade and the pre-sintered preform can be improved, resulting in the repaired gas turbine blade having good performance.
[0017] Furthermore, the method further includes machining the pre-sintered preform after the brazing.
[0018] In this disclosure, by machining the pre-sintered preform, the repaired gas turbine blade can have high shape accuracy, thereby improving the aerodynamic performance of the gas turbine blade.
[0019] Furthermore, the method further includes: cooling the pre-sintered preform and the gas turbine blade to room temperature after the brazing and before the machining.
[0020] In this disclosure, by cooling the pre-sintered preform and the gas turbine blade to room temperature, thermal stress can be fully released, thereby preventing weld cracking. Furthermore, machining at room temperature promotes dimensional stability, which in turn helps ensure the shape accuracy of the gas turbine blade.
[0021] Furthermore, the cooling is performed under a protective atmosphere or a vacuum atmosphere.
[0022] In this disclosure, by performing cooling under a protective atmosphere or a vacuum atmosphere, oxidation of the gas turbine blades during the cooling process can be avoided, resulting in the repaired gas turbine blades having good performance. Attached Figure Description
[0023] The accompanying drawings, which are included to provide a further understanding of this disclosure and form part of this disclosure, illustrate exemplary embodiments of the present disclosure and are used to explain the disclosure, but do not constitute an undue limitation of the disclosure. In the drawings: Figure 1 This is a partial cross-sectional view of a gas turbine blade according to an embodiment of the present disclosure, wherein a pre-sintered preform is positioned on the damaged portion of the gas turbine blade, and filler is filled in the pore structure.
[0024] List of reference numerals in the attached diagram: 100. Gas turbine blades; 110. Damaged portion; 120. Hole structure; 130. Tail margin; 140. Pressure side; 150. Suction side; 200. Pre-sintered preform; 300. Packing material. Detailed Implementation
[0025] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this disclosure or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without inventive effort are within the scope of protection of this disclosure.
[0026] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations according to this disclosure. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise.
[0027] Figure 1 This is a partial cross-sectional view of a gas turbine blade according to an embodiment of the present disclosure, wherein a pre-sintered preform is positioned on the damaged portion of the gas turbine blade, and filler is filled in the pore structure.
[0028] refer to Figure 1 According to embodiments of the present disclosure, a method for repairing a gas turbine blade 100 includes: providing a pre-sintered preform (PSP, or pre-sintered preform, pre-sintered preform) 200; positioning the pre-sintered preform 200 onto a damaged portion 110 of the gas turbine blade 100, the damaged portion 110 being adjacent to a hole structure 120 of the gas turbine blade 100; providing a filler 300; filling the hole structure 120 with the filler 300 to seal the hole structure 120; and after positioning and filling, heat-treating the gas turbine blade 100 and the pre-sintered preform 200 such that the pre-sintered preform 200 is brazed to the gas turbine blade 100.
[0029] As an example, the gas turbine blade 100 can be a turbine blade, such as a stationary blade in a turbine blade. Alternatively, the gas turbine blade 100 can be a moving blade in a turbine blade, or a stationary or moving blade in a compressor blade.
[0030] As an example, the hole structure 120 may include cooling holes, such as exhaust holes located at the trailing edge 130 of the gas turbine blade 100. Correspondingly, the damaged portion 110 may be located at the trailing edge 130 of the gas turbine blade 100 on the surface of the gas turbine blade 100, for example, on the pressure side 140 of the gas turbine blade 100. Of course, the locations of the damaged portion 110 and the hole structure 120 are not limited to these. For example, the damaged portion 110 may also be located on the suction side 150 of the gas turbine blade 100 on the surface of the gas turbine blade 100.
[0031] As an example, positioning may include resistance welding the pre-sintered preform 200 to the gas turbine blade 100, for example, spot welding it to the gas turbine blade 100. Alternatively or additionally, positioning may include bonding the pre-sintered preform 200 to the gas turbine blade 100, for example, by using an adhesive to bond it to the gas turbine blade 100.
[0032] In this disclosure, by brazing the pre-sintered preform 200 to the gas turbine blade 100, the strengthening phase of the gas turbine blade 100 can be prevented from deteriorating due to overheating, resulting in the repaired gas turbine blade 100 having good performance. Furthermore, by filling the pore structure 120 with filler 300, the filler 300 can prevent the pre-sintered preform 200 from flowing into the pore structure 120, thereby preventing the pore structure 120 from being blocked by the pre-sintered preform 200. This makes the method applicable to the damaged portion 110 adjacent to the pore structure 120.
[0033] refer to Figure 1 The filler 300 is configured to cure during heat treatment, and the method further includes removing the filler 300 from the pore structure 120 after brazing.
[0034] As an example, filler 300 can be a peelable solder resist. For instance, filler 300 can be in a paste form before heating and form an elastic or brittle film after heating.
[0035] As an example, removal may include supplying fluid to the pore structure 120. For example, air or water may be supplied to the pore structure 120, causing the packing 300 to leave the pore structure 120 under the impact of air or water.
[0036] In this disclosure, by curing the filler 300 during heat treatment, the filler 300 can be easily removed from the hole structure 120 after brazing, thereby improving repair efficiency.
[0037] In other embodiments, the filler can be configured to decompose into gas during heat treatment. For example, the filler can be a thermally decomposable solder resist. This eliminates the need to remove the filler from the pore structure, thereby improving repair efficiency.
[0038] refer to Figure 1 The pre-sintered preform 200 contains a high-temperature alloy (or superalloy).
[0039] As an example, the high-temperature alloy in the pre-sintered preform 200 may contain one or more of the following: nickel (Ni), chromium (Cr), cobalt (Co), tungsten (W), molybdenum (Mo), titanium (Ti), aluminum (Al), niobium (Nb), tantalum (Ta), rhenium (Re), hafnium (Hf), carbon (C), boron (B), and zirconium (Zr). For example, the pre-sintered preform 200 may contain 50 wt% to 80 wt% of Rene 80, such as 50 wt% to 70 wt% or 60 wt% to 80 wt% of Rene 80, preferably 65 wt% of Rene 80.
[0040] As an example, the high-temperature alloy in the pre-sintered preform 200 can be substantially the same as the material forming the gas turbine blade 100.
[0041] As an example, the pre-sintered preform 200 may also contain brazing filler metal, such as brazing filler metal selected from the Amdry series of materials. For example, the pre-sintered preform 200 may contain 20wt% to 50wt% brazing filler metal, such as 20wt% to 40wt% or 30wt% to 50wt% brazing filler metal, preferably 35wt% brazing filler metal.
[0042] In this disclosure, by including a high-temperature alloy in the pre-sintered preform 200, the pre-sintered preform 200 and the gas turbine blade 100 can be close to or even the same in terms of solidus temperature and liquidus temperature, thereby ensuring that the repaired gas turbine blade 100 has good performance.
[0043] refer to Figure 1 The method also includes cleaning the damaged portion 110 before positioning.
[0044] As an example, cleaning can include one or more of the following: blending, machining (such as grinding), sandblasting, and vapor phase cleaning (such as fluoride ion cleaning).
[0045] As an example, cleaning can be performed after the filler 300 has been filled into the pore structure 120. This prevents foreign matter generated during the cleaning process from entering the pore structure 120.
[0046] In this disclosure, by cleaning the damaged portion 110, the oxide layer at the damaged portion 110 can be removed and the damaged portion 110 can be made flat, thereby improving the brazing quality.
[0047] refer to Figure 1 The heat treatment is carried out under a protective atmosphere or a vacuum atmosphere.
[0048] As an example, heat treatment can be performed in a vacuum atmosphere. For instance, heat treatment may include placing the gas turbine blade 100 and the pre-sintered preform 200 in a vacuum welding furnace. In other words, the vacuum atmosphere can be provided by the vacuum welding furnace. In other instances, heat treatment can be performed in a protective atmosphere. For example, heat treatment can be performed in an inert atmosphere, such as an argon atmosphere.
[0049] In this disclosure, by performing heat treatment under a protective atmosphere or a vacuum atmosphere, oxidation of the gas turbine blade 100 during the heat treatment process can be avoided, resulting in the repaired gas turbine blade 100 having good performance.
[0050] refer to Figure 1The heat treatment temperature is 1000℃ to 1400℃, and the heat treatment duration is 40 min to 80 min.
[0051] As an example, the temperature of the heat treatment can remain substantially constant during the duration. For instance, the temperature of the heat treatment can be between 1000°C and 1300°C, or between 1100°C and 1400°C, such as between 1100°C and 1300°C, preferably 1200°C. Alternatively, the temperature of the heat treatment can vary during the duration.
[0052] As an example, the duration of heat treatment can be 40 min to 70 min or 50 min to 80 min, for example, 50 min to 70 min, preferably 60 min.
[0053] In this disclosure, by setting the heat treatment temperature to 1000°C to 1400°C and the heat treatment duration to 40 min to 80 min, the connection strength between the gas turbine blade 100 and the pre-sintered preform 200 can be improved, so that the repaired gas turbine blade 100 has good performance.
[0054] refer to Figure 1 The method also includes machining the pre-sintered preform 200 after brazing.
[0055] As an example, machining can include one or more of the following: milling, grinding, and polishing.
[0056] As an example, machining can be performed before the filler 300 is removed. This prevents foreign matter generated during machining from entering the hole structure 120.
[0057] In this disclosure, by machining the pre-sintered preform 200, the repaired gas turbine blade 100 can have high shape accuracy, thereby improving the aerodynamic performance of the gas turbine blade 100.
[0058] refer to Figure 1 The method further includes cooling the pre-sintered preform 200 and the gas turbine blade 100 to room temperature after brazing and before machining.
[0059] In this disclosure, by cooling the pre-sintered preform 200 and the gas turbine blade 100 to room temperature, thermal stress can be fully released, thereby preventing weld cracking. Furthermore, machining at room temperature promotes dimensional stability, which in turn helps ensure the shape accuracy of the gas turbine blade 100.
[0060] refer to Figure 1 Cooling is carried out under a protective atmosphere or a vacuum atmosphere.
[0061] As an example, cooling can be performed in the same atmosphere as heat treatment. For instance, in the case of heat treatment using a vacuum welding furnace, the gas turbine blade 100 and the pre-sintered preform 200 can be held in the vacuum welding furnace after heat treatment until they cool to room temperature. In other words, the vacuum welding furnace can provide a vacuum atmosphere for both heat treatment and cooling. Alternatively, cooling can be performed in a different atmosphere than heat treatment.
[0062] In this disclosure, by performing cooling under a protective atmosphere or a vacuum atmosphere, oxidation of the gas turbine blade 100 during the cooling process can be avoided, resulting in the repaired gas turbine blade 100 having good performance.
[0063] The above are merely preferred embodiments of this disclosure. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this disclosure, and these improvements and modifications should also be considered within the scope of protection of this disclosure.
Claims
1. A method for repairing gas turbine blades (100), characterized in that, include: Provide pre-sintered preforms (200); The pre-sintered preform (200) is positioned on the damaged portion (110) of the gas turbine blade (100), the damaged portion (110) being adjacent to the hole structure (120) of the gas turbine blade (100); Packing material (300); The filler (300) is filled into the pore structure (120) to seal the pore structure (120); and After the positioning and filling, the gas turbine blade (100) and the pre-sintered preform (200) are heat-treated so that the pre-sintered preform (200) is brazed to the gas turbine blade (100).
2. The method for repairing gas turbine blades (100) according to claim 1, characterized in that, The filler (300) is configured to cure during the heat treatment, and the method further includes removing the filler (300) from the pore structure (120) after the brazing.
3. The method for repairing gas turbine blades (100) according to claim 1, characterized in that, The packing material (300) is configured to decompose into gas during the heat treatment.
4. The method for repairing gas turbine blades (100) according to any one of claims 1 to 3, characterized in that, The pre-sintered preform (200) contains a high-temperature alloy.
5. The method for repairing gas turbine blades (100) according to any one of claims 1 to 3, characterized in that, The method further includes: Before the positioning, the damaged portion (110) is cleaned.
6. The method for repairing gas turbine blades (100) according to any one of claims 1 to 3, characterized in that, The heat treatment is performed under a protective atmosphere or a vacuum atmosphere.
7. The method for repairing gas turbine blades (100) according to any one of claims 1 to 3, characterized in that, The heat treatment temperature is from 1000°C to 1400°C, and the heat treatment duration is from 40 min to 80 min.
8. The method for repairing gas turbine blades (100) according to any one of claims 1 to 3, characterized in that, The method further includes: After the brazing, the pre-sintered preform (200) is machined.
9. The method for repairing gas turbine blades (100) according to claim 8, characterized in that, The method further includes: After the brazing and before the machining, the pre-sintered preform (200) and the gas turbine blade (100) are cooled to room temperature.
10. The method for repairing gas turbine blades (100) according to claim 9, characterized in that, The cooling is performed under a protective atmosphere or a vacuum atmosphere.