Deformation control method in large-size annular thin-wall part aluminizing process
By increasing the thickness of the big end mounting edge during the aluminized process of aircraft engine parts and using aluminized clamps to control deformation, the problem of difficulty in ensuring roundness and flatness in traditional processes is solved, and effective deformation control and aluminum quality of parts are achieved Improvement.
Patent Information
- Application Number
- CN202411511577.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-28
- Publication Date
- 2025-02-07
AI Technical Summary
In the aluminizing process of aircraft engine parts, traditional processes are difficult to ensure the roundness and flatness requirements of large end faces and small end inner holes, and the annular thin-walled parts are prone to deform when shaping.
By increasing the mounting edge thickness of the large end of the annular thin-walled part during machining, and clamping the parts with an aluminized clamp, the aluminized area and support surface are controlled to avoid deformation.
The deformation control of the annular thin-walled parts during the aluminum penetration process is realized, which meets the roundness and flatness requirements of the parts, reduces the shaping process, and avoids defects such as cracks in the parts.
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Figure CN119392162A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of aluminizing deformation control of aircraft engine parts, and in particular to a deformation control method during the aluminizing process of a large-sized annular thin-walled part. Background Art
[0002] Some hot end parts of aircraft engines have high working temperature, severe oxidation and corrosion atmosphere. In order to resist the high humidity oxidation and high humidity and heat corrosion in the working environment, the design requires the surface of the specified parts to be aluminized according to the use requirements to improve the corrosion and oxidation resistance of the parts. Because the aluminizing temperature of high-temperature alloys is relatively high, the commonly used aluminizing temperature is 850℃~990℃, and the aluminizing deformation problem is easy to occur during the aluminizing process.
[0003] Figure 1 The part shown is a large-sized annular thin-walled part. The outer diameter φD of the large end of the annular thin-walled part reaches φ525mm. The wall thickness t of the connection between the large end and the small end is 3-5mm. It is a typical large-sized annular thin-walled part. The large end of the annular thin-walled part has a mounting edge, and the small end has a small end inner hole φd2 and a step hole φd1. φd1=φ480mm; thickness of the large end mounting edge The process requirements of the annular thin-walled parts are: the roundness of the small end inner hole φd2 before aluminizing is required to be 0.1mm, and the roundness after aluminizing is required to be 0.3mm; the flatness of the end face T of the large end of the part before aluminizing is required to be 0.05mm, and the flatness after aluminizing is required to be 0.16mm. The traditional process has the following problems:
[0004] (1) The large end face T is fully aluminized, but in actual use, it is found that only a circle of aluminized surface close to the inner hole of the end face T is retained, so the existing process has the problem of too large aluminized area. In addition, the current part structure and aluminizing process cannot guarantee the roundness requirement of the small end inner hole φd2, and cannot guarantee the flatness requirement of the large end face T, and the thin-walled part between the large end and the small end is easily deformed during shape correction.
[0005] (2) In the traditional process, after the parts are aluminized, they need to be shaped. There are two shaping methods: cold shaping and hot shaping.
[0006] Thermal correction: Heat the parts to a certain temperature, generally the stress relief temperature, use special tooling to apply a certain pressure on the deformed surface, and keep it warm for a period of time to make the roundness and flatness of the specific surface of the parts meet the process requirements. This method will add a heating process and extend the part processing time.
[0007] Cold shaping: At room temperature, a certain pressure is applied to the surface of the part using a shaping machine or other equipment to make the roundness and flatness of a specific surface of the part meet the process requirements. Parts shaped using this method will have secondary deformation problems after being placed for a certain period of time, and this method will cause defects such as cracks in the parts. Summary of the invention
[0008] The main purpose of the present invention is to provide a deformation control method during the aluminizing process of large-sized annular thin-walled parts, aiming to solve the above technical problems.
[0009] To achieve the above object, the present invention proposes a deformation control method during aluminizing of a large-sized annular thin-walled part, comprising the following steps:
[0010] S1. Adjust the machining dimensions of the annular thin-walled parts: During machining, increase the thickness of the mounting edge of the large end of the annular thin-walled parts to ensure the roundness of the small end inner hole φd2 and the step hole φd1, as well as the flatness of the large end end surface;
[0011] S2, dividing the large end face of the annular thin-walled part into a first annular region and a second annular region, wherein the first annular region is a region obtained by expanding the edge of the inner hole of the large end by 3 to 5 mm; the first annular region is used as an aluminizing region of the large end face; and the second annular region is used as a supporting surface of an aluminizing fixture;
[0012] S3. Clamp the annular thin-walled part by using an aluminizing fixture: the aluminizing fixture is supported on the second annular area of the large end surface of the part, and the clamping part is the large end step surface of the annular thin-walled part; the aluminizing fixture includes a shaping ring, which is inserted into the step hole φd1 of the annular thin-walled part, and the shaping ring does not exert axial pressure on the annular thin-walled part;
[0013] S4, aluminizing: aluminizing the first annular area of the small end inner hole φd2 and the large end end surface of the annular thin-walled part.
[0014] Preferably, in step S1, during machining, the thickness of the large end of the annular thin-walled part behind the mounting edge increases from T1 to T2, wherein
[0015] Preferably, in step S1, the roundness of the inner hole φd2 of the small end is ensured to be 0.1 mm, and the stepped hole The roundness is 0.1mm, and the flatness of the large end face is guaranteed to be 0.05mm.
[0016] Preferably, the aluminizing fixture also includes a base and a pressure ring; a stepped countersunk hole is arranged at the center of the top surface of the base; a locking column is arranged on the base, and a first wedge block is transversely inserted on the locking column; in step S3, when the annular thin-walled part is clamped, the step surface of the stepped countersunk hole of the base is supported on the second annular area of the large end surface of the annular thin-walled part, and the pressure ring is pressed on the large end step surface of the annular thin-walled part, and after the upper end of the locking column passes through the pressure ring, the first wedge block is transversely inserted on the locking column and the pressure ring is pressed.
[0017] Preferably, the aluminizing fixture further comprises a plurality of annular supporting columns evenly distributed on the base; a hollow column is integrally formed on the base; in the step S3, when the annular thin-walled part is clamped, the shaping ring is inserted into the step hole φd1 of the annular thin-walled part, and the lower surface of the shaping ring contacts the step surface of the step hole φd1, and the outer peripheral surface of the shaping ring matches the inner hole surface of the step hole φd1; the top end of the supporting column is supported on the bottom surface of the shaping ring, so that the shaping ring does not generate axial pressure on the annular thin-walled part; a second wedge block is laterally inserted after the upper end of the hollow column passes through the shaping ring.
[0018] Preferably, in the aluminizing fixture, the step surface of the stepped countersunk hole at the top of the base is taken as the reference A, and the flatness of the reference A is required to be 0.025 mm; the parallelism of the top surface of the support column relative to the reference A is 0.03 mm; the parallelism of the lower end surface of the shaping ring relative to the reference A is 0.03 mm; the verticality of the outer peripheral surface of the shaping ring relative to the reference A is
[0019] Preferably, in the aluminizing fixture, the outer peripheral surface of the sizing ring is adjacent to the step hole. There is a clearance fit between the inner hole surfaces, and the single-side fit clearance is 0.015~0.03mm.
[0020] Preferably, the material of the aluminizing fixture is the same as that of the annular thin-walled part, both of which are high-temperature alloy GH4648.
[0021] Preferably, before performing the aluminizing in step S4, a test is first performed using a GH4648 test piece to determine the aluminizing process parameters.
[0022] Preferably, in step S4, when aluminizing, the heating parameters are: heating from room temperature to 550°C in 60±10min, keeping warm for 2h±10min; then heating to 950°C in 60±10min, keeping warm for 4h~4h10min, cooling to 500°C at a rate of ≤10°C / min, then filling with argon gas at 0.2~0.4Mpa, cooling to ≤150°C and taking out of the furnace.
[0023] Due to the adoption of the above technical solution, the beneficial effects of the present invention are as follows:
[0024] (1) In the present invention, the thickness of the mounting edge of the large end of the annular thin-walled part is increased during machining, thereby increasing the rigidity of the part. When the aluminized fixture is used for clamping, since the surface of the step hole φd1 is not aluminized, the step hole φd1 is matched with the sizing ring, and the roundness of the step hole φd1 is controlled to indirectly control the roundness of the small end inner hole φd2.
[0025] (2) In the present invention, the large end face of the annular thin-walled part is divided into regions, the first annular region is the region obtained by expanding the edge of the inner hole of the large end by 3 to 5 mm, and the remaining part is the second annular region. The first annular region is used as the aluminizing region of the large end face, and the second annular region is used as the supporting surface of the aluminizing fixture. Therefore, when the annular thin-walled part is clamped, the aluminizing fixture that controls the deformation of the part can directly clamp the second annular region of the large end face of the part. In addition, the clamping part is the large end step surface of the annular thin-walled part, and the thickness of the clamping part is relatively large, which ensures that it will not be deformed due to the clamping force, thereby avoiding deformation of the thin-walled part between the large end and the small end of the annular thin-walled part.
[0026] (3) In the present invention, by using a reasonable aluminizing fixture structure and reasonable aluminizing process parameters, selecting a suitable non-aluminizing surface on the annular thin-walled part to contact the fixture, and adopting an indirect control method, the deformation control of the part during the aluminizing process is completed without affecting the aluminizing quality of the part, thereby reducing the shape correction process of the annular thin-walled part. The results show that after aluminizing, the annular thin-walled part has a qualified aluminizing quality, and the roundness of the small end inner hole φd2 and the flatness of the first annular area of the large end end face of the part meet the requirements. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.
[0028] Figure 1 The structure and aluminizing requirements of annular thin-walled parts;
[0029] Figure 2 Schematic diagram of the area division of the large end face for adjusting the machining dimensions and the requirements for aluminizing;
[0030] Figure 3 It is a cross-sectional view of the annular thin-walled part after being clamped in the aluminizing fixture;
[0031] Figure 4It is a three-dimensional structural diagram of an annular thin-walled part after being clamped in an aluminizing fixture;
[0032] Figure 5 This is the heating curve of aluminizing.
[0033] Explanation of the accompanying drawings: 1. first annular area; 2. second annular area; 3. large end step surface; 4. shaping ring; 5. base; 5a. hollow column; 6. pressure ring; 7. locking column; 8. first wedge block; 9. supporting column; 10. second wedge block. DETAILED DESCRIPTION
[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0035] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.
[0036] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.
[0037] Combination Figures 1 to 5 As shown, a deformation control method for a large-sized annular thin-walled part during aluminizing includes the following steps:
[0038] S1. Adjust the machining dimensions of the annular thin-walled part: During machining, increase the thickness of the mounting edge of the large end of the annular thin-walled part to ensure the roundness of the inner hole φd2 of the small end and the step hole φd1, as well as the flatness of the end surface T of the large end; specifically, the thickness of the mounting edge of the large end of the annular thin-walled part increases from T1 to T2, where Ensure that the roundness of the small end inner hole φd2 is 0.1mm and the step hole The roundness is 0.1mm, and the flatness of the large end face T is guaranteed to be 0.05mm.
[0039] S2. Divide the large end face T of the annular thin-walled part into a first annular region 1 and a second annular region 2. The first annular region 1 is the region obtained by expanding the edge of the inner hole of the large end by 3 to 5 mm. Use the first annular region 1 as the aluminum-diffusion region of the large end face T. Use the second annular region 2 as the supporting surface of the aluminum-diffusion fixture.
[0040] S3. Clamp the annular thin-walled part using an aluminizing fixture: the aluminizing fixture is supported on the second annular region 2 of the large end face T of the part, and the clamping part is the large end step face 3 of the annular thin-walled part; the aluminizing fixture includes a shaping ring 4, which is inserted into the step hole φd1 of the annular thin-walled part, and the shaping ring 4 does not exert axial pressure on the annular thin-walled part.
[0041] S4, aluminizing: aluminizing the first annular region 1 of the small end inner hole φd2 and the large end end surface T of the annular thin-walled part.
[0042] The small end inner hole φd2 and the first annular region 1 on the annular thin-walled part are used as aluminizing regions. The roundness requirement of the small end inner hole φd2 before aluminizing is 0.1mm, and the roundness requirement after aluminizing is 0.3mm. After the large end face T is divided into regions, the flatness requirement of the first annular region 1 before aluminizing is 0.05mm, and the flatness requirement after aluminizing is 0.16mm. During the aluminizing process, the aluminizing surface cannot be in direct contact with the aluminizing fixture, otherwise the aluminizing quality will be affected. Therefore, when the annular thin-walled part is clamped by the aluminizing fixture, the aluminizing fixture that controls the deformation of the part directly clamps the second annular region 2 of the large end face T of the part, and does not affect the first annular region 1. In addition, the clamping part is the large end step surface 3 of the annular thin-walled part. The thickness of the clamping part is relatively large, which ensures that it will not be deformed due to the clamping force, thereby avoiding deformation of the thin-walled part between the large end and the small end of the annular thin-walled part. Since the surface of the step hole φd1 is not aluminized, the step hole is used to Cooperate with the shaping ring 4 to control the step hole The roundness of the small end inner hole is indirectly controlled The roundness.
[0043] Combination Figure 3 , Figure 4 As shown, the aluminizing fixture also includes a base 5 and a pressure ring 6; a stepped countersunk hole is arranged at the center of the top surface of the base 5; a locking column 7 is arranged on the base 5, and a first wedge block 8 is horizontally inserted on the locking column 7; in the step S3, when the annular thin-walled part is clamped, the step surface of the stepped countersunk hole of the base 5 is supported on the second annular area 2 of the large end surface T of the annular thin-walled part, and the pressure ring 6 is pressed on the large end step surface 3 of the annular thin-walled part. After the upper end of the locking column 7 passes through the pressure ring 6, the first wedge block 8 is horizontally inserted on the locking column 7 and the pressure ring 6 is pressed.
[0044] Furthermore, the aluminizing fixture further comprises a plurality of support columns 9 evenly distributed in an annular shape on the base 5; a hollow column 5a is integrally formed on the base 5; in the step S3, when the annular thin-walled part is clamped, the shaping ring 4 is inserted into the step hole φd1 of the annular thin-walled part, and the lower surface of the shaping ring 4 contacts the step surface of the step hole φd1, and the outer peripheral surface of the shaping ring 4 matches the inner hole surface of the step hole φd1; the top end of the support column 9 is supported on the bottom surface of the shaping ring 4, so that the shaping ring 4 does not generate axial pressure on the annular thin-walled part, thereby avoiding deformation of the thin-walled part between the large end and the small end of the annular thin-walled part. After the upper end of the hollow column 5a passes through the shaping ring 4, a second wedge block 10 is inserted transversely. The second wedge block 10 is used to axially press the shaping ring 4, so that the shaping ring 4 only rests on the top surface of the support column 9, avoiding the shaping ring 4 from falling off.
[0045] Combination Figure 3 As shown, in the aluminizing fixture, the step surface of the center step countersunk hole on the top surface of the base 5 is taken as the reference A, and the flatness of the reference A is required to be 0.025mm; the parallelism of the top surface of the support column 9 relative to the reference A is 0.03mm; the parallelism of the lower end surface of the shaping ring 4 relative to the reference A is 0.03mm; the verticality of the outer peripheral surface of the shaping ring 4 relative to the reference A is
[0046] In the aluminizing fixture, the outer peripheral surface of the sizing ring 4 is aligned with the step hole. The inner hole surface is clearance fit, specifically, the step hole φd1 is 480mm, and the outer peripheral surface diameter of the shaping ring 4 is The single-sided gap formed by the two is 0.015~0.03mm.
[0047] In this embodiment, the material of the aluminizing fixture is the same as that of the annular thin-walled part, both of which are high-temperature alloy GH4648. During the aluminizing heating process, the fixture and the annular thin-walled part have the same shrinkage rate due to the same material, so as to better achieve the purpose of deformation control.
[0048] Before performing aluminizing in step S4, a test is first performed using a GH4648 test piece to determine aluminizing process parameters. The test is performed specifically according to the parameters in Table 1.
[0049] Table 1 Test table for determining aluminizing process parameters
[0050]
[0051] The test shows that when the aluminizing temperature is lower than 950℃, the aluminizing quality is unqualified; when the 950℃ holding time is lower than 4h, the aluminizing quality is unqualified.
[0052] Through the above test, in step S4, when aluminizing, the heating parameters are: heating from room temperature to 550°C in 60±10min, keeping warm for 2h±10min; then heating to 950°C in 60±10min, keeping warm for 4h~4h10min, cooling to 500°C at a rate of ≤10°C / min, then filling with argon gas 0.2~0.4Mpa, cooling to ≤150°C and taking out of the furnace. The aluminizing heating curve is as follows Figure 5 shown.
[0053] Using conventional existing processes, serious deformation problems will occur during the aluminizing process. The data on the changes in the flatness and roundness of the parts before and after aluminizing are shown in Table 2.
[0054] Table 2 Flatness and roundness data of aluminizing using conventional existing process
[0055]
[0056] Using the deformation control method provided by the present invention, a total of 4 parts were produced and verified. The results showed that after aluminizing, the aluminizing quality of the parts was qualified, and the roundness and flatness of the specified surface met the requirements. The test results are shown in Table 3. Fluorescence detection shows that the deformation control method provided by the present invention does not cause any fluorescent defects to be visible on the parts.
[0057] Table 3 Flatness and roundness data of aluminum infiltration by the method provided by the present invention
[0058]
[0059] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.
Claims
1. A method for controlling deformation of a large-sized annular thin-walled part during aluminizing, characterized in that: The following steps are involved: S1. Adjust the machining dimensions of the annular thin-walled parts: During machining, increase the thickness of the mounting edge of the large end of the annular thin-walled parts to ensure the roundness of the small end inner hole φd2 and the step hole φd1, as well as the flatness of the large end end surface; S2, dividing the large end face of the annular thin-walled part into a first annular region (1) and a second annular region (2), wherein the first annular region (1) is a region obtained by expanding the edge of the inner hole of the large end outward by 3 to 5 mm; using the first annular region (1) as an aluminizing region of the large end face; and using the second annular region (2) as a supporting surface of an aluminizing fixture; S3. Clamping the annular thin-walled part by using an aluminizing fixture: the aluminizing fixture is supported on the second annular region (2) of the large end face of the part, and the clamping part is the large end step face (3) of the annular thin-walled part; the aluminizing fixture includes a shaping ring (4), and the shaping ring (4) is inserted into the step hole φd1 of the annular thin-walled part, and the shaping ring (4) does not exert axial pressure on the annular thin-walled part; S4, aluminizing: aluminizing the inner hole φd2 of the small end and the first annular region (1) of the large end surface of the annular thin-walled part.
2. A method for controlling deformation of a large-sized annular thin-walled part during aluminizing as claimed in claim 1, characterized in that: In step S1, during machining, the thickness of the large end of the annular thin-walled part behind the mounting edge increases from T1 to T2, wherein 3. The method for controlling deformation of a large-sized annular thin-walled part during aluminizing as claimed in claim 1, characterized in that: In step S1, the roundness of the inner hole φd2 of the small end is ensured to be 0.1 mm, the roundness of the step hole φd1 is ensured to be 0.1 mm, and the flatness of the end surface of the large end is ensured to be 0.05 mm.
4. A method for controlling deformation of a large-sized annular thin-walled part during aluminizing as claimed in claim 1, characterized in that: The aluminizing fixture further comprises a base (5) and a pressure ring (6); a stepped countersunk hole is arranged at the center of the top surface of the base (5); a locking column (7) is arranged on the base (5), and a first wedge block (8) is inserted transversely on the locking column (7); In step S3, when the annular thin-walled part is clamped, the step surface of the stepped counterbore of the base (5) is supported on the second annular area (2) of the large end surface of the annular thin-walled part, and the pressure ring (6) is pressed against the large end step surface (3) of the annular thin-walled part. After the upper end of the locking column (7) passes through the pressure ring (6), the first wedge block (8) is horizontally inserted on the locking column (7) and the pressure ring (6) is pressed.
5. A method for controlling deformation of a large-sized annular thin-walled part during aluminizing as claimed in claim 4, characterized in that: The aluminizing fixture further comprises a plurality of supporting columns (9) evenly distributed in an annular shape on the base (5); a hollow column (5a) is integrally formed on the base (5); In step S3, when the annular thin-walled part is clamped, the shaping ring (4) is inserted into the step hole φd1 of the annular thin-walled part, and the lower surface of the shaping ring (4) contacts the step surface of the step hole φd1, and the outer peripheral surface of the shaping ring (4) matches the inner hole surface of the step hole φd1; the top end of the supporting column (9) is supported on the bottom surface of the shaping ring (4), so that the shaping ring (4) does not generate axial pressure on the annular thin-walled part; the upper end of the hollow column (5a) passes through the shaping ring (4) and a second wedge block (10) is inserted laterally.
6. A method for controlling deformation of a large-sized annular thin-walled part during aluminizing as claimed in claim 5, characterized in that: In the aluminizing fixture, the step surface of the center stepped countersunk hole on the top surface of the base (5) is used as the reference A, and the flatness of the reference A is required to be 0.025 mm; the parallelism of the top surface of the support column (9) relative to the reference A is 0.03 mm; the parallelism of the lower end surface of the shaping ring (4) relative to the reference A is 0.03 mm; and the verticality of the outer peripheral surface of the shaping ring (4) relative to the reference A is φ0.05 mm.
7. A method for controlling deformation of a large-sized annular thin-walled part during aluminizing as claimed in claim 5, characterized in that: In the aluminizing fixture, there is a clearance fit between the outer peripheral surface of the sizing ring (4) and the inner surface of the step hole φd1, and the single-side clearance is 0.015-0.03 mm.
8. The method for controlling deformation of a large-sized annular thin-walled part during aluminizing as claimed in claim 1, characterized in that: The material of the aluminizing fixture is the same as that of the annular thin-walled part, both of which are high-temperature alloy GH4648.
9. A method for controlling deformation of a large-sized annular thin-walled part during aluminizing as claimed in claim 1, characterized in that: Before performing aluminizing in step S4, a test is first performed using a GH4648 test piece to determine aluminizing process parameters.
10. The method for controlling deformation of a large-sized annular thin-walled part during aluminizing according to claim 1, characterized in that: In step S4, when aluminizing, the heating parameters are: heating from room temperature to 550°C in 60±10min, keeping warm for 2h±10min; then heating to 950°C in 60±10min, keeping warm for 4h~4h10min, cooling to 500°C at a rate of ≤10°C / min, then filling with argon gas 0.2~0.4Mpa, cooling to ≤150°C and taking out of the furnace.