GH4169 alloy turbine disc forging method and alloy turbine disc

Abstract

The invention provides a GH4169 alloy turbine disc forging method and an alloy turbine disc, and relates to the field of aircraft part production. The method comprises the following steps: applying more than 50% of deformation to a GH4169 alloy bar within a preset forging temperature interval to obtain an intermediate billet; the initial forging temperature of the preset forging temperature zone is 990 DEG C, and the final forging temperature of the preset forging temperature zone is 930 DEG C; and the forging die is heated to be 30-50 DEG C lower than the intermediate blank, the intermediate blank is forged, and the GH4169 alloy turbine disc is obtained. The method is suitable for the forging process of the GH4169 alloy turbine disc and is used for solving the problem that coarse crystals and mixed crystals are prone to occurring in the forging process of the GH4169 alloy.

Description

Technical Field

[0001] The present application relates to the field of aircraft, specifically to the field of aircraft parts production, and in particular to a GH4169 alloy turbine disk forging method and an alloy turbine disk. Background Art

[0002] As the core rotating part of an aircraft engine, the turbine disc is subjected to the combined effects of high temperature and high stress during operation. The working conditions are extremely harsh and require long-term reliable working capabilities. Therefore, the preparation process of the turbine disc is extremely complex and technically difficult, and has long been one of the difficulties in the development of aircraft engines.

[0003] The turbine disc can be forged from GH4169 alloy.

[0004] However, coarse grains and mixed grains are prone to occur in the GH4169 alloy during the forging process, and the grain size of the GH4169 alloy cannot be improved by subsequent heat treatment. Summary of the invention

[0005] The present application provides a GH4169 alloy turbine disk forging method and alloy turbine disk, which are used to solve the coarse grain and mixed grain problems of GH4169 alloy during the forging process.

[0006] In a first aspect, the present application provides a GH4169 alloy turbine disk forging method, the method comprising: applying a deformation amount of more than 50% to the GH4169 alloy bar within a preset forging temperature range to obtain an intermediate billet; the initial forging temperature of the preset forging temperature zone is 990°C, and the final forging temperature is 930°C; the forging die is heated to 30°C to 50°C lower than the intermediate billet, and the intermediate billet is forged to obtain a GH4169 alloy turbine disk.

[0007] The GH4169 alloy turbine disk forging method provided in the present application can firstly obtain uniform grain size of each part of the billet better than the original GH4169 alloy bar by matching deformation of more than 50% and a certain forging temperature in the billet making process. In the final forming process, a near-isothermal forging process is selected to eliminate the cold die layer caused by the difference between the mold temperature and the billet temperature and the grain growth caused by the excessively high billet temperature, thereby avoiding the coarse grain and mixed grain phenomenon of the GH4169 alloy in the forging process, and ensuring that the forging process obtains a structure that meets the process requirements.

[0008] Optionally, the method further comprises: performing solution treatment and aging treatment on the GH4169 alloy turbine disk.

[0009] Optionally, the GH4169 alloy turbine disk is subjected to a solution treatment, including: heating the GH4169 alloy turbine disk to 970° C.±10° C., maintaining the constant temperature for 105 min±5 min, and then oil cooling.

[0010] Optionally, the GH4169 alloy turbine disk is subjected to aging treatment, including: heating the GH4169 alloy turbine disk to 720°C±5°C, maintaining the constant temperature for 480min±5min, then furnace cooling to 620°C±5°C at a rate of 50°C / h and keeping the temperature for 8h, and finally air cooling.

[0011] Optionally, the intermediate blank is a cake blank.

[0012] Optionally, the GH4169 alloy bar is smelted by vacuum induction and vacuum consumable processes.

[0013] Optionally, the diameter of the GH4169 alloy bar is 155 mm.

[0014] Optionally, applying a deformation amount of more than 50% to the GH4169 alloy bar within a preset forging temperature range includes: applying a deformation amount of more than 50% to the GH4169 alloy bar within a preset forging temperature range using a 20MN fast forging machine.

[0015] Optionally, the intermediate billet is forged, including: forging the intermediate billet using a 63MN hydraulic press.

[0016] In a second aspect, the present application provides a GH4169 alloy turbine disk, which is forged using the forging method described in the first aspect above.

[0017] The beneficial effects of the second aspect mentioned above can be referred to the first aspect and will not be elaborated on again. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present application 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 application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A three-dimensional diagram of the rough machining delivery of the GH4169 turbine disk forging provided in the embodiment of the present application; Figure 2 A schematic diagram of a cross section of a forging provided in an embodiment of the present application; Figure 3 A schematic diagram of a process forging a GH4169 alloy turbine disk provided in an embodiment of the present application; Figure 4 A schematic diagram of a forging intermediate blank provided in an embodiment of the present application; Figure 5 A physical picture of the intermediate blank provided in the embodiment of the present application; Figure 6 A physical picture of a forged part after forming provided in an embodiment of the present application; Figure 7 The forging simulation results provided by the embodiments of the present application; Figure 8 A schematic diagram of low-magnification inspection results of forgings provided in an embodiment of the present application; Fig. 9 This is a high-magnification structural image of the forging provided in the embodiment of the present application. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only 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 this field without creative work are within the scope of protection of this application.

[0021] It should be noted that, in the embodiments of the present application, words such as "exemplarily" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplarily" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplarily" or "for example" is intended to present related concepts in a specific way.

[0022] In order to facilitate the clear description of the technical solutions of the embodiments of the present application, in the embodiments of the present application, the words "first", "second", etc. are used to distinguish the same items or similar items with basically the same functions and effects. Those skilled in the art can understand that the words "first", "second", etc. are not limiting the quantity and execution order.

[0023] As the core rotating part of an aircraft engine, the turbine disc is subjected to the combined effects of high temperature and high stress during operation. The working conditions are extremely harsh and require long-term reliable working capabilities. Therefore, the preparation process of the turbine disc is extremely complex and technically difficult, and has long been one of the difficulties in the development of aircraft engines.

[0024] The microstructure and performance of turbine disc forgings directly affect the performance and safety of aircraft engines. Turbine discs are generally forged from high-temperature alloys, and their forging process has an important influence on the microstructure and performance of turbine discs. For example, turbine discs can be forged from GH4169 alloy.

[0025] The main technical indicators of GH4169 turbine disk forgings include low magnification, high magnification (grain size), room temperature tensile properties, high temperature tensile properties, high temperature endurance properties, as well as hardness, notch cycle endurance properties, creep properties, and low cycle strain fatigue properties tests.

[0026] However, coarse grains and mixed grains are prone to occur in the GH4169 alloy during the forging process, and the grain size of the GH4169 alloy cannot be improved by subsequent heat treatment.

[0027] Based on this, the embodiment of the present application provides a GH4169 alloy turbine disk forging method and alloy turbine disk, which can be controlled by reasonable forging process parameters, and the forging forming process directly affects the microstructure and mechanical properties of the final forging.

[0028] The following is an introduction with reference to the accompanying drawings.

[0029] Figure 1 The rough machining delivery three-dimensional diagram of the GH4169 turbine disc forging provided in the embodiment of this application. Figure 1 As shown, the upper half of the GH4169 turbine disk is a disk with a through hole in the center, and a concentric small disk with a diameter smaller than the disk protrudes from the disk, and the center of the small disk also has a through hole. The lower half of the GH4169 turbine disk is a hollow truncated cone with a through hole in the center, and the diameter of the hollow truncated cone gradually decreases from top to bottom. The centers of the through holes of the concentric small disks, the disk, and the hollow truncated cone are the same. The through holes of the concentric small disks, the through holes of the disk, and the top diameters of the through holes of the hollow truncated cone are the same. The diameter of the through hole of the hollow truncated cone gradually decreases from top to bottom.

[0030] As an example, Figure 1 The outer dimensions of the GH4169 turbine disk forging shown in the figure are Φ215 millimeters (mm) × 77 mm.

[0031] Figure 2 This is a schematic diagram of a forging cross section provided in an embodiment of the present application. Figure 2 As shown in the figure, the overall size of the forging is small, but the cross-sectional size varies greatly, and it belongs to a small turbine disk forging. Affected by the size of the forging and the bar, a difficult deformation zone is often formed at the bottom of the turbine disk, so it is very easy to produce coarse grain structure at this location. If the conventional forging forming idea is used to design the process plan for this forging, it will be difficult to ensure that the average grain size of each part of the forging cross section is ≥8.

[0032] In order to ensure that each part of the forging section obtains the organization and performance that meet the index requirements, it is necessary to ensure that each section of the forging obtains a certain amount of deformation during the die forming process to avoid the formation of deformation dead zones, and at the same time match reasonable forging process parameters.

[0033] Figure 3The schematic diagram of the process of forging a GH4169 alloy turbine disk provided in the embodiment of the present application is shown in FIG. Figure 3 As shown, the method includes the following steps: S101. Apply more than 50% deformation to the GH4169 alloy bar within a preset forging temperature range to obtain an intermediate billet.

[0034] The initial forging temperature of the preset forging temperature zone is 990°C and the final forging temperature is 930°C. Optionally, the GH4169 alloy bar material may be a GH4169 alloy with a specification of Φ155 mm. The GH4169 alloy may be smelted by vacuum induction and vacuum consumable processes.

[0035] For example, the main chemical composition of the GH4169 alloy bar can be specifically shown in the following Table 1: Table 1 As shown in Table 1, the GH4169 alloy bar mainly includes 5.25% of niobium and tantalum, 0.037% of carbon, 17.90% of chromium, 2.94% of molybdenum, 0.97% of titanium, 0.51% of aluminum, and 52.50% of nickel.

[0036] In a possible implementation, a 20MN fast forging machine may be used to apply a deformation of more than 50% to the GH4169 alloy bar within the preset forging temperature range.

[0037] Among them, a 20MN fast forging machine refers to a fast forging machine that can exert a maximum pressure of 20 meganewtons (MN).

[0038] Optionally, considering the deformation distribution of each part during the forging process, the intermediate blank can be specifically designed as a cake blank, so as to ensure that the metal of each part of the forging obtains uniform flow through the extrusion effect of the upper die.

[0039] For example, Figure 4 Schematic diagram of the forging intermediate blank provided in the embodiment of the present application. Figure 4 As shown, the intermediate blank can be specifically implemented as a cake blank, which is a solid cake blank. The main body of the cake blank is in the shape of a cake, and the bottom part is convex with a convex structure whose diameter is smaller than that of the main body.

[0040] For example, Figure 5 This is a real picture of the intermediate blank provided in the embodiment of this application. Please refer to Figure 5 In (a), Figure 5 (a) shows the top image of the intermediate billet, the main part of which is in the shape of a pancake. Figure 5 (b) in the above equation, Figure 5(b) shows an image of the bottom of the intermediate billet, on which a small pancake-like structure with a diameter smaller than that of the top pancake is protruded.

[0041] Optionally, after the blank is cut, the grain size at the center, 1 / 2R, and outer edge surface can be checked at any end face. The test results show that the grain sizes at the center, 1 / 2R, and outer edge of the trial production blank end face are 6.5, 6.5, and 9, respectively.

[0042] S102, heating the forging die to a temperature 30° C. to 50° C. lower than the intermediate billet, and forging the intermediate billet to obtain a GH4169 alloy turbine disk.

[0043] Herein, heating the forging die to a temperature 30° C. to 50° C. lower than that of the intermediate billet to forge the intermediate billet can also be understood as performing near-isothermal forging on the intermediate billet.

[0044] For example, the forging die may be heated to a temperature 30° C., 35° C., 40° C., 45° C., or 50° C. lower than the intermediate billet, etc. The embodiment of the present application does not limit the specific heating temperature of the forging die.

[0045] In a possible implementation, a 63MN hydraulic press may be used to forge the intermediate billet.

[0046] Among them, a 63MN hydraulic press refers to a hydraulic press that can exert a maximum pressure of 63MN.

[0047] For example, Figure 6 This is a real picture of the forged part after forming provided in the embodiment of this application. Please refer to Figure 6 , Figure 6 The actual image of the GH4169 alloy turbine disk obtained after forging the intermediate billet is shown in FIG. Figure 6 As shown, the surface forming quality of the (GH4169 alloy turbine disk) forging is good, without defects such as folding and cracking, and the size meets the design requirements.

[0048] For example, Figure 7 This is the forging simulation result provided in the embodiment of the present application. Figure 7 As shown in the figure, the deformation of each part of the GH4169 alloy turbine disk after near-isothermal forging, that is, Figure 7 The equivalent strain (Strain-Effective (mm / mm)) meets the process design requirements, and all parts of the forging are well filled.

[0049] The GH4169 alloy turbine disk forging method provided in the embodiment of the present application can firstly achieve uniform grain size of each part of the billet better than the original GH4169 alloy bar material by matching the deformation amount of more than 50% and a certain forging temperature in the billet making process. In the final forming process, a near-isothermal forging forming process is selected to eliminate the cold die layer caused by the difference between the mold temperature and the billet temperature and the grain growth caused by the excessively high billet temperature, thereby avoiding the coarse grain and mixed grain phenomenon of the GH4169 alloy in the forging process, and ensuring that the forging process obtains a structure that meets the process requirements.

[0050] In some possible embodiments, after the GH4169 alloy turbine disk is forged, the GH4169 alloy turbine disk may be subjected to a solution treatment and an aging treatment.

[0051] In a possible implementation, solution treatment of the GH4169 alloy turbine disk may specifically include the following steps: Step 1a: Heat the GH4169 alloy turbine disk to 970 degrees Celsius (°C) ±10°C, maintain the constant temperature for 105 minutes (min) ±5 minutes, and then oil cool.

[0052] The term "oil cooling" refers to cooling by using oil, and the oil may be, for example, quenching oil or other oils, etc. The present application embodiment does not limit this.

[0053] For example, the GH4169 alloy turbine disk may be heated to 960° C., 965° C., 970° C., 975° C., or 980° C., etc. The embodiment of the present application does not limit the specific heating temperature of the GH4169 alloy turbine disk.

[0054] For another example, the constant temperature may be maintained for 100 min, 103 min, 105 min, 108 min, or 110 min, etc. The embodiment of the present application does not limit the specific duration of the constant temperature maintenance.

[0055] In a possible implementation, the aging treatment of the GH4169 alloy turbine disk may specifically include the following steps: Step 1b, heat the GH4169 alloy turbine disk to 720℃±5℃, keep the constant temperature for 480min±5min, then furnace cool to 620℃±5℃ at a rate of 50℃ / h and keep it at that temperature for 8 hours (h), and finally air cool.

[0056] For example, the GH4169 alloy turbine disk may be heated to 715° C., 718° C., 720° C., 723° C., or 725° C., etc. The embodiment of the present application does not limit the specific heating temperature of the GH4169 alloy turbine disk.

[0057] For another example, after being heated to 720°C ± 5°C, the GH4169 alloy turbine disk can be kept at a constant temperature in the heating furnace for 475 minutes, 478 minutes, 480 minutes, 483 minutes, or 485 minutes. The embodiment of the present application does not limit the specific time for which the GH4169 alloy turbine disk is kept at a constant temperature.

[0058] For another example, after being kept at a constant temperature, the GH4169 alloy turbine disk can be furnace cooled at a rate of 50° C. / h to 615° C., 618° C., 620° C., 623° C., or 625° C., etc. The embodiment of the present application does not limit the specific furnace cooling temperature.

[0059] In some embodiments, after solution treatment and aging treatment, a comprehensive microstructure and performance analysis may be performed on the GH4169 alloy turbine disk.

[0060] For example, Figure 8 This is a schematic diagram of the low-magnification inspection results of forgings provided in the embodiments of this application. Figure 8 As shown, there are no white spots, black spots or other defects on the forging section, and the streamline meets the standard requirements. And sampling can be done Figure 8 High magnification detection was performed on the high-magnification tissues of the G1, G2, and G3 points.

[0061] For example, Fig. 9 This is a high-magnification image of the forging structure provided in the embodiment of this application. Fig. 9 As shown, Fig. 9 The above are shown from top to bottom. Figure 8 High-magnification tissue images of points G1, G2, and G3. The left side is 100-fold tissue images, and the right side is 500-fold tissue images. Fig. 9 It can be seen that the carbides at different positions of the forgings did not exceed (317164), the carbon-nitrides did not exceed (8211011 (4th level)), the δ-Ni3Nb phase did not exceed (7708203 (2nd level)), and no Laves phase was seen. The average grain sizes of G1, G2, and G3 were 10, 11, and 12, respectively, with no obvious mixed crystal and coarse grain structure.

[0062] Depend on Fig. 9 It can be seen that the test results of grain size at different positions further illustrate that the above process scheme ensures that all parts of the turbine disk forging complete dynamic recrystallization during the final near-isothermal forging die deformation process, and ultimately ensures that all parts of the forging obtain uniform and fine grains.

[0063] In some embodiments, the forgings may also be subjected to comprehensive mechanical property tests (including hardness, room temperature tensile properties, high temperature tensile properties, high temperature endurance properties, notch cycle endurance properties, creep properties, and low cycle strain fatigue properties). The specific test results are shown in Tables 2 to 7 below, and all mechanical properties meet the requirements of relevant standards.

[0064] Table 2: Room temperature tensile and hardness test results As shown in Table 2, the room temperature tensile and hardness test results can include the tensile strength (Rm, in megapascals (MPa)), the stress value when the non-proportional elongation reaches 0.2% during the stretching process (Rp 0.2 , unit MPa), elongation after fracture (A, unit %), reduction of area (Z, unit %), and Brinell hardness (HB). The above test results in the chord direction (1) and chord direction (2) are all higher than the index standards.

[0065] Table 3: High temperature tensile properties test results (650℃×20min) As shown in Table 3, under the high temperature tensile test of 650℃×20min, the tensile strength (Rm) in the chord direction (1) and the chord direction (2), the stress value (Rp) when the non-proportional elongation reaches 0.2% during the tensile process, 0.2 ), elongation after fracture (A), and section shrinkage (Z) are all higher than the index standards.

[0066] Table 4: High temperature endurance performance test results As shown in Table 4, when the temperature (T) is 650°C, the duration (t) in the tangential direction (1) is 57.9 hours, the endurance strength (σ) is 725 MPa, and the elongation after fracture (A) is 33%. The duration (t) in the tangential direction (2) is 58.8 hours, the endurance strength (σ) is 725 MPa, and the elongation after fracture (A) is 21%, all of which are higher than the index standard.

[0067] Table 5: 595℃ creep performance test results As shown in Table 5, under the conditions of 595°C and 825 MPa, the elongation after fracture in the chord direction (1) at the 25th hour was 0.054%, and the elongation after fracture in the 50th hour was 0.079%. The sampling time interval of 50-25=25 met the index standard. The elongation after fracture changed from 0.054% to 0.079%, and the change rate was greater than 5, which was higher than the index standard. The test results of the chord direction (2) were similar and also higher than the index standard.

[0068] Table 6: 595℃ notched cycle endurance test results As shown in Table 6, in the 595°C notch cycle endurance test, when the maximum stress value (σmax) is 895MPa, the minimum stress value (σmin) is 30MPa, the loading and unloading time is 90h, and the holding time is 90h according to the index standard, the fracture time is higher than the index standard.

[0069] Table 6: 455℃ low cycle strain fatigue performance test results As shown in Table 7, in the 455°C low cycle strain fatigue performance test, when the cycle rate is 30 times / min, the maximum strain is 30mm / mm, and the strain ratio is 90 according to the index standard, the fatigue life of the forging is 9132 weeks, which is higher than the index standard.

[0070] It can be seen from the above performance tests that the surface forming quality of the forgings is good, and the results of various physical and chemical tests meet the requirements of relevant standards with a certain margin.

[0071] The above technical scheme designs the forming process of GH4169 alloy turbine disk forgings by billet making + near isothermal forging, and through production trial production, the following conclusions can be drawn: (1) For GH4169 turbine disk forgings, the billet making + near-isothermal forging process is adopted to obtain forgings with good streamline and microstructure properties.

[0072] (2) The implementation of this project has important reference significance for the production of high-temperature alloy turbine disk structural forgings. It can effectively solve the coarse grain and mixed grain phenomenon caused by the cold die effect of the GH4169 turbine disk forging surface and the local uneven deformation or insufficient deformation caused by the coarse grain and mixed grain phenomenon caused by the failure of the forging to fully recrystallize during the die forming process. It provides a new production model for turbine disk structural forgings.

[0073] In an exemplary embodiment, the present application also provides a GH4169 alloy turbine disk, which is forged by the GH4169 alloy turbine disk forging method provided in the above embodiment.

[0074] Although the present application has been described in conjunction with specific features and embodiments thereof, it is obvious that various modifications and combinations may be made thereto without departing from the spirit and scope of the present application. Accordingly, this specification and the drawings are merely exemplary illustrations of the present application as defined by the appended claims, and are deemed to have covered any and all modifications, variations, combinations or equivalents within the scope of the present application. Obviously, those skilled in the art may make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

[0075] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A GH4169 alloy turbine disk forging method, characterized in that: include Applying a deformation amount of more than 50% to the GH4169 alloy bar in a preset forging temperature range to obtain an intermediate billet; the initial forging temperature of the preset forging temperature range is 990° C., and the final forging temperature is 930° C.; The forging die is heated to a temperature 30° C. to 50° C. lower than the intermediate billet, and the intermediate billet is forged to obtain a GH4169 alloy turbine disk.

2. The method according to claim 1, characterized in that The method further comprises: The GH4169 alloy turbine disk is subjected to solution treatment and aging treatment.

3. The method according to claim 2, characterized in that The solid solution treatment of the GH4169 alloy turbine disk comprises: The GH4169 alloy turbine disk is heated to 970° C.±10° C., maintained at a constant temperature for 105 min±5 min, and then oil-cooled.

4. The method according to claim 2, characterized in that: The aging treatment of the GH4169 alloy turbine disk comprises: The GH4169 alloy turbine disk is heated to 720°C±5°C, kept at a constant temperature for 480min±5min, then furnace-cooled to 620°C±5°C at a rate of 50°C / h and kept at that temperature for 8h, and finally air-cooled.

5. The method according to claim 1, characterized in that The intermediate blank is a cake blank.

6. The method according to claim 1, characterized in that The GH4169 alloy bar is smelted by vacuum induction and vacuum consumable process.

7. The method according to claim 1, characterized in that The diameter of the GH4169 alloy bar is 155 mm.

8. The method according to claim 1, characterized in that The step of applying a deformation amount of more than 50% to the GH4169 alloy bar within a preset forging temperature range includes: A 20MN fast forging machine is used to apply a deformation of more than 50% to the GH4169 alloy bar within the preset forging temperature range.

9. The method according to claim 1, characterized in that: The forging of the intermediate billet comprises: The intermediate billet was forged using a 63MN hydraulic press.

10. A GH4169 alloy turbine disk, characterized in that: The GH4169 alloy turbine disk is forged by the forging method described in any one of claims 1 to 9.

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