A two-stage disk and a manufacturing method thereof

Abstract

The application discloses a two-stage disk and a manufacturing method thereof, the two-stage disk comprises an upper-stage disk and a lower-stage disk, and the manufacturing method comprises the following steps: S1, pre-forging a titanium alloy bar through a die to obtain a pre-forged piece; S2, die forging the pre-forged piece through a die to obtain a die forged piece; S3, cutting off the region between the upper-stage disk part and the lower-stage disk part of the die forged piece, and cutting off to the region close to the connecting part of the upper-stage disk and the lower-stage disk, so that an integrated piece is obtained after cutting off; S4, heat treating the integrated piece; and S5, machining the integrated piece after the heat treatment is completed. The whole forging reduces the process, reduces the cost and the production period, prevents machining deformation caused by welding residual stress, reduces the performance of the welding seam, and avoids problems such as organization difference. In the case that the performance of the disk piece is not changed, the manufacturing cost and the period are reduced, and the shortcomings caused by the inertial friction technology and the bolt connection technology are avoided.

Description

TECHNICAL FIELD

[0001] The present application provides a two-stage disk and a manufacturing method thereof. BACKGROUND

[0002] The large passenger engine is a typical large bypass ratio fan engine, which is developed to meet the power demand of China's civil large aircraft. Compared with the large transport engine, the large passenger engine has the requirements of longer service life, higher reliability and lower cost. The high-pressure compressor disk is one of the key cold end components of the large passenger engine, which should meet the safe use under the condition of full recession while meeting the red line temperature and red line speed.

[0003] For commercial engines, the stress rises rapidly at low temperature, and the interaction of high stress and temperature change makes the load retention phenomenon more serious. In order to improve the fatigue life and reliability, the high-pressure compressor of the large passenger engine uses welding or bolt connection, and the bolt connection between the disk pieces will increase the fretting wear at the connection, reducing the service life of the disk. The main forging process of the single-stage compressor disk piece is blanking-piecing-moulding-heat treatment-machining-inspection. However, due to the difference between the joint crack propagation performance of titanium alloy welding performance and the base material, the impact performance is only half of the base material, and the alloy welding will have the problems of poor fracture toughness of heat affected zone, accelerated crack propagation, etc., which cannot meet the design requirements. SUMMARY

[0004] The technical problem to be solved by the present application is to overcome the defects of the thread connection between the disk pieces in the prior art, which reduces the service life, and the poor fracture toughness of the welding between the disk pieces, and to provide a manufacturing method of a two-stage disk.

[0005] The present application solves the above technical problems by the following technical solutions:

[0006] A manufacturing method of a two-stage disk, the two-stage disk comprising an upper disk and a lower disk, the manufacturing method of the two-stage disk comprising:

[0007] S1, pre-forging a titanium alloy bar by a die to obtain a pre-forged piece;

[0008] S2, moulding the pre-forged piece by a die to obtain a moulded piece;

[0009] S3, cutting off the area between the upper disk part and the lower disk part of the moulded piece, to the area close to the connection of the upper disk and the lower disk, and obtaining an integrated piece after cutting off;

[0010] S4, heat treating the integrated piece;

[0011] S5, machining the integrated piece after heat treatment.

[0012] In the technical solution, the two-stage disk is integrally forged, thereby reducing the process, lowering the cost and production cycle, preventing machining deformation caused by welding residual stress, reducing the performance of the welding seam and the difference in the structure, etc. The pre-forging and die forging make the large-volume integral part deform uniformly, the maximum strain and the highest temperature are well controlled, and the risk of forming a recrystallized structure is reduced. The integral part obtained by forging is locally cut, thereby improving the material performance at the connection between the upper disk and the lower disk during subsequent heat treatment. Therefore, the integral forging scheme can reduce the manufacturing cost and cycle without changing the performance of the disk, and can avoid the shortcomings caused by inertial friction and bolt connection.

[0013] Preferably, in step S3, the cutting depth is the depth to which the flaw detection probe can be inserted and detected.

[0014] In the technical solution, the die forging part is machined into a specific shape, the disk body is quenched without affecting non-destructive testing, and the performance of the core of the two-stage disk die forging part is ensured.

[0015] Preferably, the two-stage disk includes a disk inter-stage drum, and in step S3, when the die forging part is cut, the die forging part located at the disk inter-stage drum portion is hollowed in two directions from the core to the rim and from the rim to the core.

[0016] In the technical solution, the die forging part is cut along the disk inter-stage drum, so that the die forging part can be quenched, and the flaw detection probe can also be inserted into the disk inter-stage drum for detection.

[0017] Preferably, in step S4, the heat treatment of the integral part includes solid solution treatment and aging treatment in sequence.

[0018] In the technical solution, the integral part is heat treated to dissolve carbides in the matrix, eliminate stress, increase hardness and strength through aging treatment, increase plasticity and toughness, and improve the service life of the integral part.

[0019] Preferably, the heating temperature of the solid solution treatment is 800°C, and the holding time is at least 4 hours.

[0020] In the technical solution, the solid solution treatment is maintained at a relatively small temperature, and the holding time is increased, thereby saving energy.

[0021] Preferably, the heating temperature of the aging treatment is 630°C, and the holding time is at least 8 hours.

[0022] In the technical solution, the material is stored at a relatively high temperature for a relatively long time to produce the aging process.

[0023] Preferably, in step S1, the maximum equivalent plastic strain of the pre-forging part is 0.99, and the average value is 0.72.

[0024] Preferably, in step S2, the minimum value of the equivalent plastic strain of the die forging is 0.8, and the maximum value is 1.4.

[0025] In the technical solution, the minimum value of the equivalent plastic strain of the die forging is 0.8, which avoids the influence of human and equipment errors on the deformation amount in the forging process, achieves the minimum deformation amount, and ensures the microstructure and mechanical properties of the intermediate body after die forging.

[0026] Preferably, the temperature of the die forging process is always higher than the phase transition temperature of the titanium alloy bar.

[0027] In the technical solution, the die forging is performed above the phase transition temperature, so that the aluminum alloy bar is easy to produce phase transition.

[0028] A two-stage disk is made by the manufacturing method of the two-stage disk.

[0029] In the technical solution, the two-stage disk manufactured in an integrated manner avoids the shortcomings of welding or bolt connection, and reduces the manufacturing cost and cycle.

[0030] The positive progress effect of the present application is that:

[0031] The two-stage disk is integrally forged, which reduces the process while reducing the cost and production cycle, and prevents machining deformation, performance reduction at the weld, and organization difference caused by welding residual stress. Pre-forging and die forging make the large-volume integrated part deform uniformly, and the maximum strain and the highest temperature are well controlled, thereby reducing the risk of forming a recrystallized structure. The local cutting of the integrally forged integrated part improves the material performance at the connection between the upper and lower disk blades during subsequent heat treatment. Therefore, this integrated forging scheme can reduce the manufacturing cost and cycle without changing the disk performance, while avoiding the shortcomings caused by inertial friction and bolt connection. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 The flowchart of the manufacturing method of the two-stage disk in the preferred embodiment of the present application.

[0033] Figure 2 The integral forging drawing of the two-stage disk in the preferred embodiment of the present application.

[0034] Figure 3 The typical position microstructure comparison drawing of the integral two-stage disk in the preferred embodiment of the present application.

[0035] REFERENCE NUMERALS

[0036] Upper disk blade 100

[0037] Lower disk blade 200

[0038] Third-stage disk flange 1

[0039] Third stage blisk drum 2

[0040] Third stage blisk blade 3

[0041] Fourth stage blisk blade 4

[0042] Fourth stage blisk drum 5

[0043] Fourth stage blisk flange 6

[0044] Fourth stage blisk web 7

[0045] Fourth stage blisk hub 8

[0046] Blisk inter-stage drum 9

[0047] Third stage blisk web 10

[0048] Third stage blisk hub 11 DETAILED DESCRIPTION

[0049] The present application will be further described by way of example but without intending to limit the application to the described examples.

[0050] As shown in Figure 1 and Figure 2 The present application provides a two-stage disk and a manufacturing method thereof, the two-stage disk comprising an upper stage blisk 100 and a lower stage blisk 200, the upper stage blisk 100 and the lower stage blisk 200 being integrally formed and made of titanium alloy. In the present embodiment, the upper stage blisk 100 is a third stage disk of a compressor, and the lower stage blisk 200 is a fourth stage disk of the compressor.

[0051] The manufacturing method of the two-stage disk comprises:

[0052] S1, pre-forging a titanium alloy bar by a die to obtain a pre-forged piece;

[0053] S2, die forging the pre-forged piece by a die to obtain a die forged piece;

[0054] S3, cutting off a region between the upper stage blisk 100 and the lower stage blisk 200 in the die forged piece, the cutting being to a region close to a connecting portion of the upper stage blisk 100 and the lower stage blisk 200, and obtaining an integrated piece after the cutting;

[0055] S4, heat treating the integrated piece;

[0056] S5, machining the integrated piece after the heat treatment.

[0057] The two-stage disk is integrally forged, thereby reducing the process, lowering the cost and production cycle, preventing machining deformation caused by welding residual stress, reducing the performance of the welding part, and avoiding problems such as differences in the structure. The pre-forging and die forging make the large volume of the integral part deform uniformly, the maximum strain and the highest temperature are well controlled, and the risk of forming a recrystallized structure is reduced. The integral part obtained by forging is locally cut off, which improves the material performance at the connection between the upper and lower disk blades during subsequent heat treatment. Therefore, this integral forging scheme can reduce the manufacturing cost and cycle without changing the performance of the disk, while avoiding the shortcomings of inertia friction and bolt connection.

[0058] In step S1, the aluminum alloy bar is cut into a Ti17 bar with a diameter of Φ300 and a length of 620 mm. After the blank is machined and the end face is etched, the two-phase temperature Tβ-30℃ is selected for one-fire forging to about Φ400 diameter and 350 mm high. The rough shape is machined to remove burrs. The pre-forging places the material in the pre-forging die, and the material is forged to a certain shape, so that the material flow is restricted, and the deformation is more uniform than free forging. The die in step S1 is different from the die in step S2.

[0059] In step S1, the maximum equivalent plastic strain of the pre-forged pre-forging part is 0.99, and the average value is 0.72.

[0060] In step S2, the one-fire die forging is performed at a temperature T β +30℃ above the phase transition point. The average equivalent plastic strain of the die forging part is 1.08, the minimum value is 0.8, and the maximum value is 1.4, which can ensure that the deformation of the forging part is fully uniform and the structure is controlled. The die forging die is made of H13 and 5CrNiMoV. In step S2, the die forging temperature is always higher than the phase transition temperature T β , so that the forged body is easy to produce phase transition.

[0061] In step S3, the core of the die forging part is partially hollowed out, which does not affect the non-destructive testing, makes the disk body quenching, maximally reduces the effective thickness of the die forging part, and improves the performance of the core of the whole two-stage disk after heat treatment. The cutting depth is the depth that the probe can extend and detect. The die forging part is machined into a specific shape, which does not affect the non-destructive testing, makes the disk body quenching, and ensures the performance of the core of the two-stage disk die forging part.

[0062] The two-stage disk includes a disk inter-stage drum 9. In step S3, when the die forging is cut, the die forging part located at the disk inter-stage drum 9 part is hollowed out in two directions from the core to the rim and from the rim to the core. The die forging part is cut along the disk inter-stage drum 9, so that the die forging part can be quenched, and the probe can also extend into the inter-stage drum to detect without affecting the detection.

[0063] In step S4, the heat treatment system is: solution heat treatment temperature 800 DEG C, holding for at least 240 min; aging heat treatment temperature 630 DEG C, holding for at least 480 min. Solution heat treatment dissolves carbide in the matrix, eliminates stress, aging treatment increases hardness and strength, plasticity and toughness are increased, and the service life of the integral part is improved. The solution treatment keeps a small temperature, and the holding time is increased, so that the energy can be saved. The aging treatment stores the material at a high temperature for a long time, so that the aging process is generated.

[0064] In step S5, the integral part after the heat treatment is machined to process the upper blade disc 100 and the lower blade disc 200.

[0065] The application also discloses a two-stage disc made by the two-stage disc manufacturing method. The two-stage disc manufactured in an integrated manner avoids the defects of welding or bolt connection, and reduces the manufacturing cost and period.

[0066] Table 1 shows the room temperature and high temperature tensile property results of the two-stage disc integral forging and the single-stage disc forging in the key area mechanical property focus direction. The blade chord direction, the blade radial direction, the web radial direction, the inter-stage drum chord direction and the hub chord direction room temperature tensile properties are similar. The two-stage disc forging web radial 200 DEG C high temperature tensile strength is higher than that of the single-stage disc forging. Therefore, the tensile property of the two-stage disc forging is equal to or higher than that of the single-stage disc forging.

[0067] Table 1 comparison of single-stage disc and two-stage disc forging room temperature tensile properties in each position and direction

[0068]

[0069]

[0070] As shown in Table 2, the fracture toughness properties of the two-stage disc web positions C-R and R-C are higher than those of the single-stage disc web corresponding positions and directions, meeting the technical requirements.

[0071] Table 2 comparison of single-stage disc and two-stage disc forging fracture toughness properties in each position and direction

[0072]

[0073] As Figure 2 and 3 shown, Figure 3 the third stage blade disc flange 1, the third stage blade disc drum 2, the third stage blade disc blade 3, the fourth stage blade disc blade 4, the fourth stage blade disc drum 5, the fourth stage blade disc flange 6, the fourth stage blade disc web 7, the fourth stage blade disc hub 8, the blade disc inter-stage drum 9, the third stage blade disc web 10 and the third stage blade disc hub 11 are included.

[0074] Particular attention is paid to Figure 2The middle disc disc level drum 9 position is in the core of the overall forging, that is, the center of the disc section thickness, and the performance after heat treatment is theoretically the worst. The corresponding mechanical properties are the disc level drum chord position in Table 2. The room temperature mechanical properties are 1145Mpa, which is slightly lower than the strength of the single-stage disc drum position, but the plasticity is higher, which meets the standard requirements and design requirements. The advantages of this scheme are illustrated.

[0075] In summary, the mechanical properties of the two-stage disc forging are equivalent or higher than those of the single-stage disc forging.

[0076] Comparison and analysis of microstructures of key areas of two-stage disc overall forging and single-stage disc forging Figure 2 The forging form is shown.

[0077] From the microstructures of the six key areas: blade tip, blade root, drum, web, hub, and inter-stage drum, the microstructures of the twelve places of the disc shaft overall forging and the single-stage disc forging are all network basket organizations formed after forging and heat treatment. The needle-shaped alpha phase in the beta grain is obvious, all the original beta grain boundaries have been broken, and no coarse, flat and continuous grain boundary alpha phase is found. The microstructures are consistent and meet the design performance requirements. Figure 2 The 9 position (inter-stage drum) needs special attention, which is in the center of the disc section thickness, and its microstructure (see Figure 3 (l)) is consistent with that of the single-stage disc at the same position (see Figure 3 (i)).

[0078] Therefore, the microstructure of the two-stage disc forging is consistent with that of the single-stage disc forging.

[0079] Although the specific embodiments of the present application are described above, those skilled in the art should understand that this is only an example, and the protection scope of the present application is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present application, and such changes and modifications fall within the protection scope of the present application.

Claims

1. A manufacturing method of a two-stage disk including an upper stage disk and a lower stage disk, characterized by, The manufacturing method of the double-stage disk comprises: S1, pre-forging a titanium alloy bar by a die to obtain a pre-forged piece; S2, die forging the pre-forged piece by a die to obtain a die forged piece; S3, cutting off the region between the upper disk part and the lower disk part of the die forged piece to the region close to the connection of the upper disk and the lower disk, and obtaining an integrated piece after cutting off; S4, heat treating the integrated piece; S5, machining the integrated piece after heat treatment; In step S3, the cutting depth is the depth that the flaw detection probe can reach and detect; the double-stage disk comprises a disk inter-stage drum, and in step S3, when the die forged piece is cut off, the die forged piece at the disk inter-stage drum part is hollowed out in two directions from the core to the rim and from the rim to the core; In step S1, the maximum value of the equivalent plastic strain of the pre-forged piece is 0.99, and the average value is 0.72; In step S2, the minimum value of the equivalent plastic strain of the die forged piece is 0.8, and the maximum value is 1.

4.

2. The manufacturing method of a dual stage disk according to claim 1, wherein In step S4, the heat treatment of the integrated piece comprises solid solution treatment and aging treatment in sequence.

3. The manufacturing method of a dual stage disk according to claim 2, wherein The heating temperature of the solid solution treatment is 800℃, and the holding time is at least 4 hours.

4. The manufacturing method of a dual stage disk according to claim 2, wherein The heating temperature of the aging treatment is 630℃, and the holding time is at least 8 hours.

5. The method of manufacturing a dual stage disk as claimed in claim 1, wherein, The temperature of the die forging treatment is always higher than the phase transition temperature of the titanium alloy bar.

6. A two-stage disk characterized in that, The double-stage disk is manufactured by the manufacturing method of the double-stage disk according to any one of claims 1-5.

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