Method for repairing cracks of double-layer structure nickel-based superalloy hot end component of aero-engine

Abstract

The invention relates to the technical field of aero-engine maintenance, and particularly discloses an aero-engine double-layer-structure nickel-based superalloy hot end component crack repairing method which comprises the steps that (1) the surface and the interior of a crack of a double-layer-structure nickel-based superalloy hot end component are cleaned through a high-activity gas cleaning technology; (2) the cracks are welded and repaired through a welding method with the low heat input characteristic; and (3) the welding repair position is polished. The problems that in the prior art, a nickel-based high-temperature alloy hot end component of a double-layer structure has the double-layer structure characteristic, the surface of the middle part of an interlayer cannot be cleaned in a conventional mechanical polishing mode, many oxides and high-temperature sinter exist, and the repairing quality is affected are solved.

Description

Technical Field

[0001] The present application relates to the technical field of aircraft engine maintenance, and in particular to a method for repairing cracks in a hot end component of a double-layer nickel-based high-temperature alloy of an aircraft engine. Background Art

[0002] A double-layer nickel-based high-temperature alloy hot end component on a certain type of aircraft engine has crack defects due to the high working environment temperature during service. Due to the double-layer structure of the hot end component, the middle part of the interlayer cannot be cleaned by conventional mechanical grinding, and there are many oxides and high-temperature sintered products, which affects the quality of repair. Summary of the invention

[0003] The purpose of the present application is to provide a method for repairing cracks in a double-layer nickel-based high-temperature alloy hot-end component of an aircraft engine, so as to solve the problem in the prior art that the double-layer nickel-based high-temperature alloy hot-end component has a double-layer structure, the middle part of the interlayer cannot be cleaned by conventional mechanical grinding, and there are more oxides and high-temperature sintered products, which affects the repair quality.

[0004] To achieve the above-mentioned purpose, the embodiment of the present application provides a method for repairing cracks in a hot end component of a double-layer nickel-based high-temperature alloy of an aircraft engine, comprising: step 1) using a highly active gas cleaning technology to clean the surface of the hot end component of the double-layer nickel-based high-temperature alloy and the inside of the crack;

[0005] Step 2) using a welding method with low heat input characteristics to weld and repair the crack;

[0006] Step 3) grinding the welding repair position.

[0007] Optionally, before step 1), the method further comprises:

[0008] The sand blasting method is used to remove the thermal insulation coating on the surface of the double-layer nickel-based high-temperature alloy hot end component.

[0009] Optionally, the sand used in the sand blasting method is 80 mesh white corundum, and the compressed air pressure used is 0.4 MPa.

[0010] Optionally, the step 1) includes:

[0011] The hot end component of the double-layer nickel-based high-temperature alloy is cleaned by using high-temperature and highly active gas HF, and pulse cleaning is achieved through pressure changes.

[0012] Optionally, the step 1) includes:

[0013] The hot end component of the double-layer structure nickel-based high-temperature alloy is cleaned at a temperature of 950° C.±15° C. and under vacuum conditions for 60 min±10 min, at which time the pressure is 250 mabr±20 mabr and the HF flow rate is 10 LPM±3 LPM;

[0014] Clean the hot end parts of the double-layer nickel-based high-temperature alloy at a temperature of 950°C ± 15°C and atmospheric pressure for 30min ± 5min. At this time, the HF flow rate is 10LPM ± 3LPM.

[0015] The hot end part of the double-layer structure nickel-based high-temperature alloy is maintained at a temperature of 950°C ± 15°C and a positive pressure of 1100mAbr ± 20mAbr for 30min ± 5min, at which time the HF flow rate is 0LPM;

[0016] The hot end component of the double-layer structure nickel-based high-temperature alloy is maintained at a temperature of 950°C±15°C and vacuum conditions for 30min±5min, at which time, the HF flow rate is 0LPM.

[0017] Optionally, the step 2) includes:

[0018] The welding material used for welding repair is HGH648 nickel-based high-temperature alloy, the main welding current used is 30A~50A, and the fast-frequency welding current used is 40A~60A.

[0019] Optionally, after step 2), the method further includes:

[0020] Use radiographic inspection to check the weld locations to ensure there are no cracks.

[0021] Optionally, after step 3), the method further includes:

[0022] Thermal spraying is used to restore the thermal insulation coating on the surface of the hot end component of the double-layer nickel-based high-temperature alloy.

[0023] Optionally include:

[0024] Repeat the cleaning step of step 1) to perform 3 to 5 cycles of cleaning on the hot end component of the double-layer nickel-based high-temperature alloy.

[0025] The embodiments of the present application have the following advantages:

[0026] Compared with the prior art, the above technical solution targets cracks in a double-layer nickel-based high-temperature alloy hot-end component, provides a high-activity gas cleaning technology for the surface and crack interior of the double-layer nickel-based high-temperature alloy hot-end component and a welding repair technology with low heat input characteristics, thereby improving the repair quality and reducing the repair cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the implementation methods of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings described below are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0028] Figure 1 A flow chart of a method for repairing cracks in a hot end component of a double-layer nickel-based high-temperature alloy of an aircraft engine provided in at least one embodiment of the present application. DETAILED DESCRIPTION

[0029] The following is a description of the implementation of the present application by specific specific embodiments. People familiar with the technology can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0030] It should also be noted that the terms "step 1)", "step 2)", "step 3)", "S1", "S2", "S3", etc. in the claims and specification of the present application are used to distinguish different steps rather than to describe a specific order or sequence. It should be understood that these steps can be executed substantially in parallel or in reverse order under appropriate circumstances, depending on the functions involved.

[0031] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0032] The present application embodiment provides a method for repairing cracks in a hot end component of a double-layer nickel-based high-temperature alloy of an aircraft engine, referring to Figure 1 , Figure 1 A flowchart of a method for repairing cracks in a hot end component of a double-layer nickel-based high-temperature alloy of an aircraft engine provided in at least one embodiment of the present application. It should be understood that the method may also include additional blocks not shown and / or may omit the blocks shown, and the scope of the present application is not limited in this respect. The steps include:

[0033] S1. Sand blasting: using a sand blasting method to remove the thermal insulation coating on the surface of the hot end component of the double-layer nickel-based high-temperature alloy.

[0034] Specifically, the sand used in the sand blasting method is 80 mesh white corundum, and the compressed air pressure used is 0.4 MPa.

[0035] S2. Highly active gas cleaning: The highly active gas cleaning technology is used to clean the surface of the hot end component of the double-layer structure nickel-based high-temperature alloy and the inside of the cracks.

[0036] Specifically, high temperature and high activity gas HF is used to clean the hot end component of the double-layer nickel-based high temperature alloy, and pulse cleaning is achieved through pressure changes; in some embodiments, specifically including:

[0037] S2.1. First, the hot end component of the double-layer structure nickel-based high-temperature alloy is cleaned at a temperature of 950°C ± 15°C and vacuum conditions for 60min ± 10min. At this time, the pressure is 250mabr ± 20mabr and the HF flow rate is 10LPM ± 3LPM.

[0038] S2.2. Subsequently, the hot end components of the double-layer structure nickel-based high-temperature alloy are cleaned at a temperature of 950°C ± 15°C and atmospheric pressure for 30 min ± 5 min, at which time the HF flow rate is 10 LPM ± 3 LPM;

[0039] S2.3, secondly, keep the hot end component of the double-layer structure nickel-based high-temperature alloy at a temperature of 950°C ± 15°C and a positive pressure of 1100mAbr ± 20mAbr for 30min ± 5min, at which time, the HF flow rate is 0LPM;

[0040] S2.4, then, keep the hot end component of the double-layer structure nickel-based high-temperature alloy at a temperature of 950°C ± 15°C and vacuum conditions for 30min ± 5min, at which time, the HF flow rate is 0 LPM;

[0041] S2.5. Finally, repeat the above steps S2.1 to S2.4 and perform cyclic cleaning 3 to 5 times.

[0042] S3. Welding: The cracks are repaired by welding using a welding method with low heat input characteristics.

[0043] Specifically, the welding material used for welding repair is HGH648 nickel-based high-temperature alloy, the main welding current used is 30A to 50A, and the fast-frequency welding current used is 40A to 60A.

[0044] S4. Radiographic inspection: Use radiographic inspection to check the welding position to ensure there are no cracks.

[0045] S5. Manual grinding: grinding the welding repair position.

[0046] S6. Thermal spraying: Use thermal spraying to restore the thermal insulation coating on the surface of the double-layer nickel-based high-temperature alloy hot end components.

[0047] In summary, compared with the prior art, the embodiment of the present application provides a high-activity gas cleaning technology for the surface and crack interior of a double-layer nickel-based high-temperature alloy hot-end component crack and a welding repair technology with low heat input characteristics, thereby improving the repair quality and reducing the repair cost.

[0048] Specifically, the beneficial effects of this application include:

[0049] 1. The use of highly active gas cleaning technology can effectively clean the surface of the hot end components with a double-layer structure and the inside of the cracks, remove the oxides and high-temperature sintered products in the middle part of the interlayer, as well as the oxides inside the cracks, and improve the repair quality;

[0050] 2. Using welding methods with low heat input characteristics can effectively reduce welding heat input, reduce welding stress and improve repair quality.

[0051] Note that, unless otherwise directly stated, all features disclosed in this specification (including any attached claims, abstracts and drawings) may be replaced by alternative features for achieving the same, equivalent or similar purposes. Therefore, unless otherwise explicitly stated, each feature disclosed is only an example of a group of equivalent or similar features. Where used, further, preferably, further and more preferably are simple beginnings for elaborating another embodiment based on the aforementioned embodiment, and the content of the further, preferably, further or more preferably followed by the combination with the aforementioned embodiment constitutes a complete construction of another embodiment. Several further, preferably, further or more preferably settings following the same embodiment can be arbitrarily combined to form another embodiment.

[0052] In the implementation of functions and steps, the corresponding functions and steps in various embodiments may also occur in a different order than shown. For example, two consecutive functions and steps may actually be performed or implemented substantially in parallel, and they may sometimes be performed or implemented in the opposite order, depending on the functions involved.

[0053] Although the present application has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements may be made to the present application. Therefore, these modifications or improvements made without departing from the spirit of the present application all fall within the scope of protection claimed in the present application.

Claims

1. A method for repairing cracks in hot end components of double-layer nickel-based high-temperature alloys of aircraft engines, characterized in that: include: Step 1) using a highly active gas cleaning technology to clean the surface of the hot end component of the double-layer nickel-based high-temperature alloy and the inside of the crack; Step 2) using a welding method with low heat input characteristics to weld and repair the crack; Step 3) grinding the welding repair position.

2. The method for repairing cracks in hot end components of double-layer nickel-based high-temperature alloy of an aircraft engine according to claim 1, characterized in that: Before step 1), the method comprises: The sand blasting method is used to remove the thermal insulation coating on the surface of the double-layer nickel-based high-temperature alloy hot end component.

3. The method for repairing cracks in hot end components of double-layer nickel-based high-temperature alloy of an aircraft engine according to claim 2, characterized in that: The sand used in the sand blasting method is 80 mesh white corundum, and the compressed air pressure used is 0.4 MPa.

4. The method for repairing cracks in hot end components of double-layer nickel-based high-temperature alloy of an aircraft engine according to claim 1, characterized in that: The step 1) comprises: The hot end component of the double-layer nickel-based high-temperature alloy is cleaned by using high-temperature and highly active gas HF, and pulse cleaning is achieved through pressure changes.

5. The method for repairing cracks in hot end components of double-layer nickel-based high-temperature alloy of an aircraft engine according to claim 4, characterized in that: The step 1) comprises: The hot end component of the double-layer structure nickel-based high-temperature alloy is cleaned at a temperature of 950° C.±15° C. and under vacuum conditions for 60 min±10 min, at which time the pressure is 250 mabr±20 mabr and the HF flow rate is 10 LPM±3 LPM; Clean the hot end parts of the double-layer nickel-based high-temperature alloy at a temperature of 950°C ± 15°C and atmospheric pressure for 30min ± 5min. At this time, the HF flow rate is 10LPM ± 3LPM. The hot end part of the double-layer structure nickel-based high-temperature alloy is maintained at a temperature of 950°C ± 15°C and a positive pressure of 1100mAbr ± 20mAbr for 30min ± 5min, at which time the HF flow rate is 0LPM; The hot end component of the double-layer structure nickel-based high-temperature alloy is maintained at a temperature of 950°C±15°C and vacuum conditions for 30min±5min, at which time, the HF flow rate is 0LPM.

6. The method for repairing cracks in hot end components of double-layer nickel-based high-temperature alloy of an aircraft engine according to claim 1, characterized in that: The step 2) comprises: The welding material used for welding repair is HGH648 nickel-based high-temperature alloy, the main welding current used is 30A~50A, and the fast-frequency welding current used is 40A~60A.

7. The method for repairing cracks in hot end components of double-layer nickel-based high-temperature alloy of an aircraft engine according to claim 1, characterized in that: After step 2), the method further comprises: Use radiographic inspection to check the weld locations to ensure there are no cracks.

8. The method for repairing cracks in hot end components of double-layer nickel-based high-temperature alloy of an aircraft engine according to claim 1, characterized in that: After step 3), the method further includes: Thermal spraying is used to restore the thermal insulation coating on the surface of the hot end component of the double-layer structure nickel-based high-temperature alloy.

9. The method for repairing cracks in hot end components of double-layer nickel-based high-temperature alloy of an aircraft engine according to claim 5, characterized in that: include: Repeat the cleaning step of step 1) to perform 3 to 5 cycles of cleaning on the hot end component of the double-layer nickel-based high-temperature alloy.

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