Machining method and device for high-temperature alloy diffuser casing

Abstract

The invention discloses a machining method and device for a high-temperature alloy diffuser casing. Welding stress is removed and corrected by applying acting force to an upper mounting edge, a cone and a lower mounting edge of the diffuser casing in cooperation with heating and heat preservation. The traditional welding stress removal and correction procedures are combined into one procedure of thermal correction, the machining device comprising the cover plate, the positioning ring, the bottom plate and the pressing plate is designed to be matched to complete thermal correction, the correction acting force is provided through the deformation difference when the machining device is heated, the temperature parameter and the time parameter are adjusted, and the thermal correction efficiency is improved. And the traditional welding stress removal and correction procedures can be replaced by the thermal correction procedure. The machining efficiency is improved, the energy consumption is reduced, and the finished product quality of the diffuser casing is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of aero-engine manufacturing, and in particular relates to a processing device and a processing method for a high-temperature alloy diffuser casing. Background Art

[0002] The diffuser case is a typical part in aircraft engines and is widely used in various types of turbojet and turbofan aircraft engines. With the continuous development of materials science, high-temperature alloy materials have good fatigue performance and fracture toughness, and their use in engine parts is increasing. However, during the welding, forming and machining processes, parts are prone to internal stress, causing deformation of the parts. Once a part is deformed, corresponding manual corrections are required, which greatly increases the production cycle of the product and the production cost of the product.

[0003] At present, the diffuser casing is a typical irregular thin-walled part. The current processing process is: ... automatic argon arc welding - welding stress removal - correction - ..., this process uses the upper and lower structures to apply pressure to the outer surface of the casing respectively during the actual processing, because the wall thickness difference between the upper and lower mounting edges and the cone (t = 0.8 ~ 1.0mm) is large ( Figure 2 It is difficult to control the deformation during the correction process, which can easily lead to "wrong sides" and damage the parts. Summary of the invention

[0004] The present invention aims to design a processing method and device for a high-temperature alloy diffuser casing. The device designs the gap size of the upper and lower mounting edges and the cone according to the structural characteristics of the parts and the linear expansion coefficient of the material, so as to achieve the purpose of overall thermal calibration of the diffuser casing. At the same time, by selecting appropriate temperature parameters, the "welding stress removal-correction" in the traditional process flow can be combined into a "thermal calibration" process, which improves the processing quality of the parts and greatly improves the processing rate of the parts.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A processing method for a high-temperature alloy diffuser casing, wherein the outer surface of the upper mounting edge of the diffuser casing is provided with a groove, and the outer surface of the lower mounting edge is toothed. The processing method comprises welding the upper mounting edge, the cone and the lower mounting edge of different thicknesses by argon arc welding, and after the argon arc welding, eliminating the welding stress and correcting the outer dimensions by thermal profiling at the same time. During the thermal profiling process, a profiling force is applied to the upper mounting edge, the cone and the lower mounting edge as a whole in the following manner:

[0007] Apply an axial force from top to bottom to the upper end surface of the upper mounting edge, and apply a radial force from inside to outside to the inner ring surface of the upper mounting edge;

[0008] Apply a radial force from inside to outside to the inner conical surface of the cone;

[0009] An axial force from bottom to top is applied to the lower end surface of the lower mounting edge, an axial force from top to bottom is applied to the upper end surface of the lower mounting edge, and a radial force from inside to outside is applied to the inner ring surface of the lower mounting edge.

[0010] As a scheme, the upper mounting edge, cone and lower mounting edge are assembled with the same thermal calibration fixture, and the calibration is achieved by controlling the deformation of the upper mounting edge, cone and lower mounting edge to be smaller than the deformation of the thermal calibration fixture during the thermal calibration process, and the calibration amount is controlled by controlling the size of the gap between the upper mounting edge, cone and lower mounting edge in the radial direction of the diffuser casing and the thermal calibration fixture surface.

[0011] As a solution, a material whose linear expansion coefficient when heated is greater than that of the upper mounting edge, the cone and the lower mounting edge is selected as the preparation material of the thermal calibration fixture.

[0012] As a solution, the material of the upper mounting edge, cone and lower mounting edge is GH3044;

[0013] The material of the assembly fixture is 1Cr18Ni9Ti;

[0014] The temperature of the thermal calibration is 900±10℃;

[0015] The heat preservation time of the thermal calibration is 3.5h to 4.0h.

[0016] A processing device for a high-temperature alloy diffuser casing, comprising:

[0017] A bottom plate, the outer diameter of the bottom plate being larger than the outer diameter of the lower mounting edge;

[0018] A positioning ring, the positioning ring is detachably connected to the upper end surface of the bottom plate, the positioning ring comprises an upper annular surface and a lower annular surface, and the upper annular surface and the lower annular surface are connected by a conical surface;

[0019] A cover plate, the cover plate being detachably mounted on the upper annular surface of the positioning ring;

[0020] The pressing plates are evenly distributed on the upper end surface of the bottom plate, and at least a part of the pressing plates is located above the lower annular surface of the positioning ring.

[0021] As a solution, the positioning ring is connected to the base plate by screws inserted into the lower annular surface thereof.

[0022] As a solution, a weight-reducing notch is provided on the conical surface of the positioning ring.

[0023] As a solution, the cover plate is connected to the upper annular surface of the positioning ring through a column penetrating the cover plate, and the column presses the cover plate and the upper annular surface of the positioning ring through a wedge block and a nut.

[0024] As a solution, an eccentric wheel is arranged at the upper end of the pressure plate, the rotating shaft of the eccentric wheel is connected to the upper end surface of the base plate through a movable bolt, and a handle is also connected to the eccentric wheel.

[0025] As a solution, the upper end surface of the base plate is further provided with a lifting ring, and the circumferential surface of the cover plate is further provided with lifting screws.

[0026] Compared with the traditional cold calibration method, the device designed by the present invention applies pressure to the diffuser casing under high temperature conditions, which can ensure that the internal stress generated by welding and forming inside the diffuser casing is fully released. Compared with the traditional hot calibration method, the device designed by the present invention performs overall calibration of the upper and lower mounting edges and cones with large structural differences (mainly shape and thickness differences) through reasonable gap design. Traditional hot calibration is difficult to meet the overall calibration of such casings.

[0027] Compared with the prior art, the present invention has the following advantages:

[0028] (1) Through the coordination of the cover plate, the positioning ring, the bottom plate and the pressure plate, and by controlling the thermal expansion coefficient of the heat calibration fixture material to be greater than that of the diffuser casing, and setting the gap difference between different positions on the heat calibration fixture and different thickness positions of the diffuser casing, the deformation control difficulty of the mounting edge, cone and lower mounting edge on complex casing parts is solved, and the problem of the difficulty in removing the diffuser casing from the heat calibration fixture after heat calibration is also solved.

[0029] (2) By adjusting the temperature and time parameters, the traditional welding stress removal process and correction process are optimized into one process, which improves the processing efficiency and reduces energy consumption;

[0030] (3) The driving structure of the pressure plate, the clamping structure of the cover plate and the installation structure of the positioning ring are cleverly designed, easy to load and unload, and simple to operate;

[0031] (4) Through the design and manufacture of the device, thermal calibration is used instead of manual calibration, which not only ensures the size of the parts, but also eliminates the stress concentration caused by welding and forming, thereby improving product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a comparison diagram of the conventional process route of the diffuser casing and the process route of the present invention;

[0033] Figure 2 is a three-dimensional view of the diffuser casing of the present invention;

[0034] Figure 3It is a schematic diagram of the assembly in the processing state of the present invention;

[0035] Figure 4 It is a three-dimensional diagram of the positioning ring corresponding to the inner profile of the processing device in the present invention;

[0036] Figure 5 is a three-dimensional diagram of the diffuser casing of the present invention after being assembled on the processing device;

[0037] In the figure; 1-base plate; 2-positioning ring; 3-pressure plate; 4-cover plate; 5-column; 6-wedge block; 7-A-type straight handle; 8-fork-shaped eccentric wheel; 9-first cylindrical head hexagon socket screw; 10-second cylindrical head hexagon socket screw; 11-swing bolt; 12-A-type lifting eye screw; 13-hexagonal thin nut; 14-first cylindrical pin; 15-second cylindrical pin. DETAILED DESCRIPTION

[0038] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments, but it should not be understood that the scope of the subject matter described in the present invention is limited to the following embodiments. Without departing from the above-mentioned technical ideas of the present invention, various modifications, substitutions and changes made according to the common technical knowledge and customary means in the field are included in the scope of the present invention.

[0039] In this embodiment, a processing device is designed as a thermal calibration fixture for a high-temperature alloy diffuser casing. The design idea of ​​the processing device is as follows: Figure 2 As shown, the diffuser casing is an irregular thin-walled part, the outer surface of the upper mounting edge is a concave groove, the middle part is a thin-walled cone, the outer surface of the lower mounting edge is a toothed shape, and the thickness of the upper mounting edge, the thin-walled cone and the lower mounting edge are different. According to the different linear expansion coefficients, 1Cr18Ni9Ti is selected as the manufacturing material of the processing device, and the gap size is reasonably designed according to the part structure. For example, the thickness of the upper mounting edge and the lower mounting edge is larger, and the deformation generated during the welding process is smaller, while the thickness of the cone is smaller, and the deformation generated during the welding process is larger. Therefore, combined with the linear expansion of the thermal calibration fixture in the radial direction of the diffuser casing, the gap from the profile corresponding to the upper mounting edge and the lower mounting edge on the thermal calibration fixture to the upper mounting edge and the lower mounting edge is increased, and the calibration amount of the thermal calibration fixture to the upper mounting edge and the lower mounting edge is reduced. At the same time, the gap from the profile corresponding to the cone part on the thermal calibration fixture to the cone is reduced, and the calibration amount of the thermal calibration fixture to the cone is increased. Therefore, a thermal calibration fixture can be used to realize the overall thermal calibration of the upper mounting edge, the lower mounting edge and the cone of different thicknesses on the diffuser casing in one heating process. There is no need to use a separate fixture to independently calibrate different thickness areas on the diffuser casing. After the heat calibration is completed, the heat calibration fixture can be removed smoothly because the shrinkage is greater than the diffuser casing.

[0040] like Figure 3 As shown, the deformation of the diffuser casing is controlled by the following scheme:

[0041] First, for the inner surface of the diffuser casing, such as Figure 4 As shown, the base plate 1, the positioning ring 2 and the cover plate 4 are matched, the base plate 1 and the positioning ring 2 are fastened with a second cylindrical head hexagonal screw 10, the positioning ring 2 and the cover plate 4 are fastened with a column 5, a wedge block 6 and a hexagonal thin nut 13, and the inner surface of the diffuser casing is thermally calibrated. According to the different linear expansion coefficients of the materials, a certain margin is left between the diffuser casing and the processing device. Under high temperature conditions, the deformation of the positioning ring 2 is greater than that of the diffuser casing, so that the diffuser casing is "squeezed" to an ideal position to meet the size requirements of the diffuser casing.

[0042] Secondly, the lower mounting edge is pressed against the bottom plate 1 by means of the movable bolt 11, the pressure plate 3 and the fork-shaped eccentric wheel 8. The upper mounting edge is fixed by means of the column 5, the wedge block 6, the cover plate 4 and the hexagonal thin nut 13. The three-dimensional image of the processing device after the diffuser casing is assembled is shown in FIG. Figure 5 A type eye screw 12 is designed on the bottom plate 1 as a lifting structure, and a cylindrical head hexagon socket screw 9 is designed on the cover plate 4 as a lifting structure to facilitate assembly during thermal calibration.

[0043] Through reasonable gap design (increasing the gap from the profile corresponding to the upper mounting edge and the lower mounting edge on the thermal calibration fixture to the upper mounting edge and the lower mounting edge, and reducing the gap from the profile corresponding to the cone part on the thermal calibration fixture to the cone, the specific size of the gap is calculated according to the linear expansion coefficient and heating temperature of the thermal calibration fixture material, and the deformation of the upper mounting edge, the lower mounting edge and the cone is measured, and its basic principle is: calibration amount = thermal calibration fixture linear expansion coefficient × (thermal calibration temperature-initial temperature) × thickness of the thermal calibration fixture at this position-gap), not only can the deformation of the upper and lower mounting edges be corrected at the same time, but also the straightness of the inner profile of the diffuser casing cone can be ensured. In addition, through the use of the A-type straight handle 7 and the fork-type eccentric wheel 8 (the A-type straight handle 7 is fixed on the fork-type eccentric wheel 8 through the first cylindrical pin 14, and the fork-type eccentric wheel 8 is connected to the movable bolt 11 with the second cylindrical pin 15 as the rotating shaft), the loading and unloading of the diffuser casing is fast and efficient, and the processing efficiency of the diffuser casing is further improved.

[0044] In this embodiment, the above-mentioned processing device is used in conjunction with process optimization to achieve deformation control of the high-temperature alloy diffuser casing.

[0045] like Figure 1 As shown, at present, the processing technology for the diffuser casing is "...automatic argon arc welding-welding stress removal-correction-...". Through the design and use of the above-mentioned processing device, the processing technology can be optimized to "...automatic argon arc welding-thermal correction-...".

[0046] by Figure 2 Taking the diffuser casing shown in the figure as an example, its material is GH3044, which is a solid solution strengthened high temperature alloy, and the temperature of the solid solution treatment is 1120-1160℃; the material of the processing device is 1Cr18Ni9Ti, which is an austenitic stainless steel, and the temperature of the solid solution treatment is 1060±10℃. Under the premise of not changing the organizational morphology of the diffuser casing and the processing device, the parameters of the thermal calibration are explored through experiments, and finally the temperature of the thermal calibration is set to 900±10℃. Using this temperature to heat treat the diffuser casing can not only remove the welding stress of the diffuser casing, but also achieve the purpose of thermal calibration.

[0047] In addition, for the selection of thermal calibration holding temperature, based on the theory of heat transfer, in addition to the thickness of the diffuser casing itself, the thickness of the processing device must also be considered. A short holding time cannot achieve the purpose of thermal calibration, and a long holding time will affect the diffuser casing matrix. Through experiments, the final holding time was determined to be 3.5h to 4.0h.

[0048] In summary, if Figure 1 As shown, through the design and use of processing equipment, the processing technology of the diffuser casing is optimized from "...automatic argon arc welding-welding stress removal-correction-..." to "...automatic argon arc welding-thermal correction-...", which can not only greatly shorten the processing cycle of parts and reduce energy consumption, but also improve the processing quality of parts and reduce deformation.

[0049] The following are the specific implementation steps of the present invention:

[0050] (1) Preparation before assembly:

[0051] Before using the device to assemble parts, the contact surface between the device and the parts must be cleaned to ensure that there is no dirt or foreign matter that may affect the thermal calibration of the parts; in addition, the surface of the parts also needs to be inspected to ensure that there is no mechanical damage or dirt.

[0052] (2) Parts assembly:

[0053] First, use a crane to place the processing device on the ground, take out the wedge block 6 and the cover plate 4 and place them aside. At the same time, rotate the A-shaped straight handle 7 to ensure that the pressure plate 3 can leave a certain space for the lower installation edge.

[0054] Secondly, place the part coaxially on the positioning ring 2, ensure that the lower mounting edge is tightly fitted with the base plate 1, then place the cover plate 4 on the upper mounting edge of the part, insert the wedge 6 and press it, and rotate the A-type straight handle 7 at the same time to fasten the lower mounting edge to the base plate 3 through the pressure plate 3 (Note: during the tightening process of the wedge 6 and the A-type straight handle 7, the diagonal tightening method must be adopted).

[0055] (3) Thermal calibration:

[0056] The assembled parts and processing equipment are hoisted onto the table of the trolley furnace by a crane, the trolley furnace door is closed, the heating temperature is set to 900°C, the insulation time is 3.5 to 4.0 hours, and heat calibration treatment is performed.

[0057] (4) Release:

[0058] After the diffuser casing is heated, it is cooled to room temperature with the furnace, and then the diffuser casing and the processing device are lifted out of the trolley furnace, the wedge block 6 is taken out and the cover plate 4 is removed, the A-shaped straight handle 7 is rotated to release the pressure plate 3, and the diffuser casing is taken out to complete the entire thermal calibration process.

[0059] The contents not described in detail in the specification of the present invention belong to the prior art known to the professional and technical personnel in the field. Although the illustrative specific embodiments of the present invention are described above to facilitate the understanding of the present invention by the technical personnel in the field, it should be clear that the present invention is not limited to the scope of the specific embodiments. For ordinary technicians in the field of this technology, as long as various changes are within the spirit and scope of the present invention defined and determined by the attached claims, these changes are obvious, and all inventions and creations using the concept of the present invention are protected.

Claims

1. A method for processing a high-temperature alloy diffuser casing, wherein the outer surface of the upper mounting edge of the diffuser casing has a groove, and the outer surface of the lower mounting edge is toothed, characterized in that: The processing method includes welding the upper mounting edge, cone and lower mounting edge of different thicknesses by argon arc welding, and eliminating the welding stress and correcting the external dimensions by heat correction after argon arc welding. During the heat correction process, the correction force is applied to the upper mounting edge, cone and lower mounting edge as a whole in the following manner: Apply an axial force from top to bottom to the upper end surface of the upper mounting edge, and apply a radial force from inside to outside to the inner ring surface of the upper mounting edge; Apply a radial force from inside to outside to the inner conical surface of the cone; An axial force from bottom to top is applied to the lower end surface of the lower mounting edge, an axial force from top to bottom is applied to the upper end surface of the lower mounting edge, and a radial force from inside to outside is applied to the inner ring surface of the lower mounting edge.

2. The method for processing a high-temperature alloy diffuser casing according to claim 1, characterized in that: The upper mounting edge, cone and lower mounting edge are assembled with the same thermal profiling fixture, and the profiling is achieved by controlling the deformation of the upper mounting edge, cone and lower mounting edge to be smaller than the deformation of the thermal profiling fixture during the thermal profiling process, and the profiling amount is controlled by controlling the gap size between the upper mounting edge, cone and lower mounting edge in the radial direction of the diffuser casing and the profile of the thermal profiling fixture.

3. The method for processing a high-temperature alloy diffuser casing according to claim 2, characterized in that: A material whose linear expansion coefficient when heated is greater than that of the upper mounting edge, the cone and the lower mounting edge is selected as the preparation material of the thermal calibration fixture.

4. The method for processing a high-temperature alloy diffuser casing according to claim 2, characterized in that: The material of the upper mounting edge, cone and lower mounting edge is GH3044; The material of the assembly fixture is 1Cr18Ni9Ti; The temperature of the thermal calibration is 900±10℃; The heat preservation time of the thermal calibration is 3.5h to 4.0h.

5. A processing device for a high-temperature alloy diffuser casing, characterized in that: include: A bottom plate (1), wherein the outer diameter of the bottom plate (1) is greater than the outer diameter of the lower mounting edge; A positioning ring (2), the positioning ring (2) being detachably connected to the upper end surface of the bottom plate (1), the positioning ring (2) comprising an upper annular surface and a lower annular surface, the upper annular surface and the lower annular surface being connected via a conical surface; A cover plate (4), wherein the cover plate (4) is detachably mounted on the upper annular surface of the positioning ring (2); A pressure plate (3), wherein the pressure plate (3) is evenly distributed on the upper end surface of the bottom plate (1), and at least a portion of the pressure plate (3) is located above the lower annular surface of the positioning ring (2).

6. The processing device for a high-temperature alloy diffuser casing according to claim 5, characterized in that: The positioning ring (2) is connected to the base plate (1) by means of screws inserted into the lower annular surface thereof.

7. The processing device for a high-temperature alloy diffuser casing according to claim 5, characterized in that: The conical surface of the positioning ring (2) is provided with a weight-reducing notch.

8. The high temperature alloy diffuser casing processing device according to claim 5, characterized in that: The cover plate (4) is connected to the upper annular surface of the positioning ring (2) via a column (5) penetrating the cover plate (4), and the column (5) presses the cover plate (4) and the upper annular surface of the positioning ring (2) tightly via a wedge block (6) and a nut.

9. The high temperature alloy diffuser casing processing device according to claim 5, characterized in that: An eccentric wheel is arranged at the upper end of the pressure plate (3), the rotating shaft of the eccentric wheel is connected to the upper end surface of the bottom plate (1) through a movable bolt (11), and a handle is also connected to the eccentric wheel.

10. The high temperature alloy diffuser casing processing device according to claim 5, characterized in that: The upper end surface of the base plate (1) is also provided with a lifting ring, and the circumferential surface of the cover plate (4) is also provided with lifting screws.

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