Thermomechanical treatment method for nickel alloy disc parts

Abstract

The invention belongs to the technical field of nickel alloy treatment, and provides a thermomechanical treatment method for nickel alloy disc parts, which comprises the following steps: obtaining a nickel alloy blank, and heating to perform first thermomechanical processing to form a disc blank with an initial contour; the disc blank with the initial contour is heated to be subjected to first heat treatment; heating the disc blank subjected to the first heat treatment until the local part is subjected to second heat machining to form a disc blank close to the final outline; the disc blank close to the final contour is heated to be subjected to second-time heat treatment; and finally, plate blanks with different grain sizes in different areas are obtained. According to the method, under the condition that an over-solid-solution grain structure is obtained in the whole part, grains with larger sizes can be obtained locally.

Description

Technical Field

[0001] This invention belongs to the field of nickel alloy processing technology, and specifically relates to a thermomechanical treatment method for nickel alloy disc-shaped parts. Background Technology

[0002] In industry, γ'-strengthened nickel alloys are commonly used forging to manufacture components that need to operate at high temperatures, such as disc-shaped parts in aero engines. In turbofan and turboshaft engines, the temperature and stress at the center and edges of these nickel alloy disc-shaped parts differ significantly during operation. The edges of these parts operate at higher temperatures, thus requiring better resistance to high-temperature creep and environmental damage. While the center operates at lower temperatures, it bears greater centrifugal loads, thus requiring materials / microstructures with higher static strength. To address this, disc-shaped parts can be manufactured with different microstructures and properties at the center and edges to achieve better overall performance.

[0003] For manufacturing nickel alloy disc-shaped parts with different microstructures / properties at different locations, there are currently several technical solutions. One is to first manufacture two or more rotating bodies with different compositions and / or properties, and then weld / connect them into a concentric disc-shaped part. Another is to first prepare a disc blank with the same composition and initial microstructure, and then perform different heat treatments on different locations (e.g., the highest heat treatment temperature experienced by the center and the edge is different) to obtain different microstructures and mechanical properties at different locations (e.g., the technology disclosed in US6660110 can use special tooling to heat the center of the disc blank at a temperature lower than the solid solution line of the γ' phase in the nickel alloy used, while heating the edge of the disc blank at a temperature higher than the solid solution line of the γ' phase in the nickel alloy used, thereby obtaining a subsolution grain structure with a grain size of about 10 at the center and an oversolution grain structure with a grain size of 5 at the edge). For manufacturing nickel alloy discs using alloy powder, different sizes of alloy powder can be selected for different locations on the final product before hot pressing. Then, different microstructures and mechanical properties can be obtained at different locations on the final product through the same thermomechanical process (e.g., hot isostatic pressing and heat treatment) (as disclosed in CN103691952). Another method involves subjecting different locations on the disc blank to thermomechanical processing / forging with varying deformation amounts before the single-temperature solution heat treatment that ultimately determines the material's grain structure. This results in relatively finer grains in areas with larger initial deformation and relatively coarser grains in areas with smaller initial deformation after the final heat treatment (as mentioned in US005571345). This method utilizes the principle that different initial deformation amounts and initial microstructure sizes result in different grain growth rates during the same heat treatment process, thus achieving different grain structures at different locations on the disc blank.

[0004] With the significant increase in the overall operating temperature of nickel alloy rotating disk components in various engines, these parts require higher temperature resistance, especially the ability to obtain larger grain sizes at the edges of the highest operating temperatures to improve creep and environmental damage resistance. Since applying different temperatures to different regions in a single heat treatment is extremely difficult, and traditional isothermal forging followed by solution heat treatment struggles to uniformly obtain grains of size ≥4 in all or part of the disk blank, new thermomechanical treatment methods for nickel alloys are needed to obtain nickel alloy disk components with different grain structures in different regions. Summary of the Invention

[0005] To address the above problems, this invention proposes a thermomechanical treatment method for nickel alloy disc-shaped parts, comprising the following steps: Obtain a nickel alloy billet and heat the nickel alloy billet to... The heated nickel alloy billet is subjected to a first thermomechanical process within the appropriate superplastic forming process range for the corresponding material to form a disc with an initial profile. The pre-processed blank with its initial contour is heated to... Perform the first heat treatment; The blank after the first heat treatment is heated to... Then, a second thermomechanical process is performed on the local part of the blank in the superplastic forming process range suitable for the corresponding material to form a blank that is close to the final contour. Heat the blank, which is close to the final shape, to... Perform a second heat treatment; Ultimately, disk blanks with different grain sizes in different regions are obtained.

[0006] Furthermore, the nickel alloy billet is a nickel-based high-temperature alloy strengthened by the γ' phase.

[0007] Furthermore, The temperature is the superplastic forming temperature of the corresponding stage of the processed nickel alloy material, and the strain rate applied during the first thermomechanical processing is also within the superplastic forming process range of the corresponding stage of the processed nickel alloy material.

[0008] Furthermore, the first thermomechanical processing includes at least one multi-fire forging process with similar temperatures and strain rates, and without any heat treatments above the thermomechanical processing temperature in between, to form a blank with an initial profile.

[0009] Furthermore, The temperature should not exceed 10°C above the solid solution line of the γ' phase in the processed nickel alloy.

[0010] Furthermore, The superplastic forming temperature is the temperature at which the nickel alloy material at the corresponding stage is processed, and the strain rate applied during the second thermomechanical processing is also within the superplastic forming process range of the nickel alloy material at the corresponding stage.

[0011] Furthermore, for the blank that is close to the final contour in Perform a second heat treatment. It is higher than the solid solution line of the γ' phase in the selected nickel alloy.

[0012] Beneficial effects: 1. The thermomechanical treatment method for nickel alloy disc-shaped parts of the present invention includes obtaining a nickel alloy billet and heating the nickel alloy billet to... The heated nickel alloy billet is subjected to a first thermomechanical process within the suitable superplastic forming range for the corresponding material to form a disc blank with an initial contour; the processed disc blank with the initial contour is then heated to... Perform the first heat treatment; heat the coil after the first heat treatment to... Then, a second thermomechanical process is performed on the blank within the appropriate superplastic forming process range for the corresponding material to form a blank close to the final contour; the blank close to the final contour is heated to... A second heat treatment is performed; ultimately, a blank with different grain sizes in different regions is obtained. This invention can obtain over-solution grains in some localized areas while achieving over-solution grains in the entire part. Compared with the central subsolution and edge over-solution structure obtained by the dual-temperature heat treatment technology, it can improve the overall service temperature capability of the part, especially by obtaining a localized uniform structure with a grain size of grade 3 or higher with excellent creep resistance. In addition, the final solution heat treatment is performed at a single temperature, which simplifies the control.

[0013] 2. This invention, through step-by-step and zoned hot deformation and heat treatment, selectively obtains a fully solution-treated coarse-grained microstructure with a grain size difference of up to 5 levels at different locations on the billet after heat treatment at a final temperature above the solution line of the γ'-strengthened nickel alloy used. Furthermore, the obtained solution-treated microstructure is highly uniform across different regions, even in areas with grain sizes larger than 4 levels after two thermomechanical processing steps. Moreover, there is no abnormal grain growth within these large-grained regions. This nickel alloy preparation method can meet the demands on the microstructure and properties of parts due to the significantly increased overall operating temperature of nickel alloy rotating components in current engines. This process is applicable to almost all polycrystalline γ'-strengthened nickel-based superalloys, especially materials including those after extrusion / forging, and is also suitable for hot isostatically pressed billets with superplastic forming properties.

[0014] 3. The thermomechanical treatment method for nickel alloy disc-shaped parts of the present invention includes treating the disc blank profile at a temperature higher than the γ' solid solution line in the selected nickel alloy. A second heat treatment is then performed to obtain a solution-treated coarse-grained structure throughout the entire blank. By controlling the temperature of the subsolution heat treatment during the two thermomechanical processing steps and the parameters of the second thermomechanical processing, the grain size difference at different locations of the prepared part after the final solution heat treatment can be controlled.

[0015] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention can be realized and obtained by means of the structures pointed out in the description and the drawings. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic flowchart of the thermomechanical treatment method for nickel alloy disc-shaped parts in an embodiment of the present invention is shown.

[0018] Figure 2 A schematic diagram illustrating the implementation effect of the thermomechanical treatment method for nickel alloy disc-shaped parts in an embodiment of the present invention is shown.

[0019] Figure 3 A schematic diagram illustrating the implementation process of the thermomechanical treatment method for nickel alloy disc-shaped parts in an embodiment of the present invention is shown.

[0020] In the figure, 1. Nickel alloy disc-shaped part; 2. Central region of part with smaller grain size; 3. Edge region of part with larger grain size; 4. Nickel alloy disc-shaped part; 5. Outline of disc blank after the first thermomechanical treatment; 6. Outline of disc blank after the second thermomechanical treatment. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Example 1: refer to Figure 1 A thermomechanical treatment method for nickel alloy disc-shaped parts includes the following steps: Obtain a nickel alloy billet and heat the nickel alloy billet to... The heated nickel alloy billet is subjected to a first thermomechanical process within the appropriate superplastic forming process range for the corresponding material, such as atmospheric isothermal forging or vacuum isothermal forging, to form a disc with an initial profile close to the expected shape.

[0023] The pre-processed blank with its initial contour is heated to... The first heat treatment is performed; specifically, after the first thermomechanical processing, the billet undergoes a first solution heat treatment at a temperature not exceeding 10°C above the γ' solution line of the selected nickel alloy, resulting in increased grain size in the billet after the first thermomechanical processing. If the temperature after the first solution heat treatment is lower than the γ' solution line of the selected nickel alloy, the material in the billet after heat treatment is in a subsolid state with a grain size of 9-10, and does not change into an oversolid state with a grain size exceeding 8. If the temperature after the first solution heat treatment is equal to or slightly higher than the γ' solution line of the selected nickel alloy, the material in the billet after heat treatment is in an oversolid state with a grain size of approximately 8-9.

[0024] The blank after the first heat treatment is heated to... Then, a second thermomechanical process is performed on a portion of the blank within the suitable superplastic forming range for the corresponding material to form a blank that approximates the final contour. The temperature selected for this thermomechanical process... The strain rate should be selected based on the material composition and rheological properties after the first heat treatment to determine the appropriate process range for superplastic forming, ensuring that the disc does not crack during this thermomechanical processing. This thermomechanical processing can deform only a portion of the disc, for example, to obtain larger grains (smaller grain size values) in the edge region, and the deformation amount during thermomechanical processing should be less than that during the first thermomechanical processing.

[0025] For the blank that is close to the final profile A second heat treatment is then performed. Specifically, after the second thermomechanical processing, the blank is heat-treated at a temperature above the γ' solid solution line of the selected nickel alloy. This results in a solution-treated grain structure throughout the blank, with larger grain sizes in the areas that have undergone two thermomechanical processing operations compared to areas that have only undergone one. The part can then be aged at a temperature well below the γ' phase solid solution line.

[0026] Ultimately, disk blanks with different grain sizes in different regions are obtained, resulting in... Figure 2 The blank shown. Figure 2 The grain size of the central region 2 of the part with a relatively small grain size is approximately grade 4 to 8. Figure 2 The grain size of the edge region 3 of the part with a relatively large medium grain size is about 0 to 4.

[0027] This invention, through preliminary thermomechanical treatment, allows for the formation of over-solution grain structures of varying sizes in different regions of the entire part via a single-temperature heat treatment during the final solution heat treatment process. Compared to a dual-temperature approach in solution heat treatment, this method improves the overall temperature resistance of the part, especially in areas with localized grain sizes of 4 or higher. For example, localized grain sizes of 1 can significantly enhance the material's resistance to creep and environmental damage above 700°C. Furthermore, since the final solution heat treatment is performed at a single temperature, the method is simple to control and requires no complex tooling.

[0028] The composition (mass fraction) of the γ' phase-strengthened nickel-based superalloy used in this case is Cr 14.0%~17.0%, Co 11.0%~15.0%, W 3.0%~6.0%, Mo 2.0%~5.0%, Al 2.0%~5.0%, Ti 2.0%~4.0%, Nb 0.5%~2.5%, Zr 0.0%~0.06%, C 0.01%~0.1%, B 0.01%~0.3%, Fe 0.0%~1.0%, with the balance being Ni and other trace elements beneficial to superalloys and unavoidable trace or impurity elements.

[0029] Furthermore, The temperature is the superplastic forming temperature of the corresponding stage of nickel alloy material, and the strain rate applied during the first thermomechanical processing is also within the superplastic forming process range of the corresponding stage of nickel alloy material being processed. The value range is 1010°C to 1090°C.

[0030] Furthermore, the strain rate of the thermomechanical processing in this stage is less than or equal to 0.01 s⁻¹. -1 .

[0031] Furthermore, the first thermomechanical processing includes at least one multi-fire forging process with similar temperatures and strain rates, and without any heat treatment exceeding the thermomechanical processing temperature in between.

[0032] In this embodiment, The temperature should not exceed 10°C above the solid solution line of the γ' phase in the processed nickel alloy. At this temperature, γ' does not completely dissolve back into the matrix, and the remaining γ' pins the grain boundaries, limiting grain growth. Therefore, although the grain size increases after this heat treatment compared to the first thermomechanical heat treatment, it remains a subsolid solution state with a grain size of 9-10, and does not transform into an oversolid solution state with a grain size exceeding 8.

[0033] Furthermore, the blank after the first heat treatment is heated to... Then, a second thermomechanical processing is performed on a portion of the blank within the suitable superplastic forming process range for the corresponding material, forming a blank that approximates the final contour. The temperature during this thermomechanical processing... The temperature for the superplastic forming of the corresponding stage of the nickel alloy material being processed is defined as the superplastic forming temperature. The processed area is only a portion of the blank with an initial profile after the first thermomechanical processing (e.g., the edge portion where larger grain sizes are desired), thus forming a blank close to the final profile. The strain rate applied during the second thermomechanical processing is also within the superplastic forming process range of the corresponding stage of the nickel alloy material being processed, not exceeding 0.005 s. -1 .

[0034] Furthermore, for the blank that is close to the final contour in Perform a second heat treatment. The solid solution line is higher than that of the γ' phase in the selected nickel alloy. After this heat treatment, the material in the entire billet has a solid solution grain structure, and the grain size of the material after the second thermomechanical processing is larger (smaller grain size value) than that of the material after only the first thermomechanical processing.

[0035] Furthermore, the billet is subjected to heat treatment such as aging at a temperature much lower than the solid solution line of the γ' phase of the nickel alloy used.

[0036] Example 2: It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other, and the various embodiments can be referenced and cited in each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0037] The composition (mass fraction) of the γ'-strengthened nickel-based alloy used in this case is Cr 14.0%~17.0%, Co 11.0%~15.0%, W 3.0%~6.0%, Mo 2.0%~5.0%, Al 2.0%~5.0%, Ti 2.0%~4.0%, Nb 0.5%~2.5%, Zr 0.0%~0.06%, C 0.01%~0.1%, B 0.01%~0.3%, Fe 0.0%~1.0%, with the balance being Ni and other trace elements beneficial to high-temperature alloys and unavoidable trace or impurity elements.

[0038] The solid solution line of the γ'-strengthened nickel-based alloy used in this case is approximately 1120°C.

[0039] The alloy used in this case was in an extruded state before undergoing the following thermomechanical treatments, with a grain size value greater than or equal to 10, and possessed superplastic forming ability.

[0040] The raw billet of the alloy is processed into a suitable shape and size, and then subjected to thermomechanical treatment step by step.

[0041] The first thermomechanical treatment was performed at a temperature between 1010°C and 1090°C for no more than 0.01 s. -1 The strain rate is measured to obtain... Figure 3 The outline of the blank after the first thermomechanical treatment is shown in Figure 5. Figure 3 4 is a nickel alloy disc-type component.

[0042] The blank after the first thermomechanical heat treatment is subjected to subsolid heat treatment at 1090°C~1110°C.

[0043] For the edge portion of the subsolid heat-treated disc, the temperature should be within the range of 1030°C to 1100°C for no more than 0.005 s. -1 The strain rate is subjected to a second thermomechanical treatment to obtain... Figure 3 The outline of the billet after the second thermomechanical treatment is shown in Figure 6.

[0044] The billet was subjected to solution heat treatment at 1150°C for 1-2 hours.

[0045] After cooling, it undergoes aging heat treatment between 700°C and 800°C.

[0046] Ultimately, we obtained the following: Figure 2 The blank shown is a nickel alloy disc, with part number 1 being a nickel alloy disc component. Figure 2 The grain size of the central region 2 of the part with a relatively small grain size is approximately grade 6-8. Figure 2 The grain size of the edge region 3 of the part, which has a relatively large grain size, is approximately grade 2 to 4, and the grain size is uniform throughout, with no abnormally large grains present. Due to the larger grain size, the creep resistance of the edge region 3 at 700°C / 690MPa is 3 to 10 times that of the central region 2 of the part.

[0047] Example 3: It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other, and the various embodiments can be referenced and cited in each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0048] The composition (mass fraction) of the γ'-strengthened nickel-based alloy used in this case is Cr 14.0%~17.0%, Co 11.0%~15.0%, W 3.0%~6.0%, Mo 2.0%~5.0%, Al 2.0%~5.0%, Ti 2.0%~4.0%, Nb 0.5%~2.5%, Zr 0.0%~0.06%, C 0.01%~0.1%, B 0.01%~0.3%, Fe 0.0%~1.0%, with the balance being Ni and other trace elements beneficial to high-temperature alloys and unavoidable trace or impurity elements.

[0049] The solid solution line of the γ'-strengthened nickel-based alloy used in this case is approximately 1120°C.

[0050] The alloy used in this case was in an extruded state before undergoing the following thermomechanical treatments, with a grain size value greater than or equal to 10, and possessed superplastic forming ability.

[0051] The raw billet of the alloy is processed into a suitable shape and size, and then subjected to thermomechanical treatment step by step.

[0052] The first thermomechanical treatment was performed at a temperature between 1010°C and 1090°C for no more than 0.01 s. -1 The strain rate is measured to obtain... Figure 3 The outline of the blank after the first thermomechanical treatment is shown in Figure 5. Figure 3 4 is a nickel alloy disc-type component.

[0053] The blank after the first thermomechanical heat treatment was subjected to solution heat treatment at 1125°C to 1130°C. This temperature is higher than the γ' phase solution line of the alloy used, but not more than 10°C above the γ' phase solution line.

[0054] After the first solution heat treatment, the edge portion of the billet is heated at 1030°C to 1100°C for no more than 0.005 s. -1 The strain rate is subjected to a second thermomechanical treatment to obtain... Figure 3 The outline of the billet after the second thermomechanical treatment is shown in Figure 6.

[0055] The billet was subjected to solution heat treatment at 1150°C for 1-2 hours.

[0056] After cooling, it undergoes aging heat treatment between 700°C and 800°C.

[0057] Ultimately, we obtained the following: Figure 2 The blank shown is a nickel alloy disc, with part number 1 being a nickel alloy disc component. Figure 2 The grain size of the central region 2 of the part with a relatively small grain size is approximately grade 6 to 8. Figure 2 The grain size of the edge region 3 of the part, which has a relatively large grain size, is approximately grade 2 to 4, and the grain size is uniform throughout, with no abnormally large grains present. Due to the larger grain size, the creep resistance of the edge region 3 at 700°C / 690MPa is 3 to 10 times that of the central region 2 of the part.

[0058] Example 4: The composition (mass fraction) of the γ'-strengthened nickel-based alloy used in this case is Cr 14.0%~17.0%, Co 11.0%~15.0%, W 3.0%~6.0%, Mo 2.0%~5.0%, Al 2.0%~5.0%, Ti 2.0%~4.0%, Nb 0.5%~2.5%, Zr 0.0%~0.06%, C 0.01%~0.1%, B 0.01%~0.3%, Fe 0.0%~1.0%, with the balance being Ni and other trace elements beneficial to high-temperature alloys and unavoidable trace or impurity elements.

[0059] The solid solution line of the γ'-strengthened nickel-based alloy used in this case is approximately 1120°C.

[0060] The alloy used in this case was in an extruded state before undergoing the following thermomechanical treatments. It had a grain size finer than grade 10 and possessed superplastic forming ability.

[0061] The raw billet of the alloy is processed into a suitable shape and size, and then subjected to thermomechanical treatment step by step.

[0062] The first thermomechanical treatment was performed at a temperature between 1010°C and 1090°C for no more than 0.01 s. -1 The strain rate is directly obtained. Figure 3 The outline of the blank after the second thermomechanical treatment is shown in Figure 6. Figure 3 4 is a nickel alloy disc-type component.

[0063] The thermomechanically heat-treated coils are subjected to subsolid heat treatment at 1090°C~1110°C.

[0064] The billet is subjected to solution heat treatment at 1150°C (i.e., the second solution heat treatment) for 1 to 2 hours.

[0065] After cooling, it undergoes aging heat treatment between 700°C and 800°C.

[0066] Ultimately, we obtained the following: Figure 2 The blank shown has a uniform oversolution structure with a grain size of about 6 to 8 in all positions. The edges and center of the part are basically the same, and the grain size difference is usually no more than 1 level.

[0067] Example 5: The composition (mass fraction) of the γ'-strengthened nickel-based alloy used in this case is Cr 14.0%~17.0%, Co 11.0%~15.0%, W 3.0%~6.0%, Mo 2.0%~5.0%, Al 2.0%~5.0%, Ti 2.0%~4.0%, Nb 0.5%~2.5%, Zr 0.0%~0.06%, C 0.01%~0.1%, B 0.01%~0.3%, Fe 0.0%~1.0%, with the balance being Ni and other trace elements beneficial to high-temperature alloys and unavoidable trace or impurity elements.

[0068] The solid solution line of the γ'-strengthened nickel-based alloy used in this case is approximately 1120°C.

[0069] The alloy used in this case was in an extruded state before undergoing the following thermomechanical treatments. It had a grain size finer than grade 10 and possessed superplastic forming ability.

[0070] The raw billet of the alloy is processed into a suitable shape and size, and then subjected to thermomechanical treatment step by step.

[0071] The first thermomechanical treatment was performed at a temperature between 1010°C and 1090°C for no more than 0.01 s. -1 The strain rate is measured to obtain... Figure 3 The outline of the blank after the second thermomechanical treatment is shown in Figure 5. Figure 3 4 is a nickel alloy disc-type component.

[0072] The second thermomechanical treatment is performed only on a localized area of ​​the billet, with a temperature range of 1010°C to 1090°C and a strain rate not exceeding 0.005 s⁻¹. -1 ,get Figure 3 The outline of the blank after the second thermomechanical treatment is shown in Figure 6. Figure 3 4 is a nickel alloy disc-type component.

[0073] The billet was subjected to solution heat treatment at 1150°C for 1-2 hours.

[0074] After cooling, it undergoes aging heat treatment between 700°C and 800°C.

[0075] Ultimately, we obtained the following: Figure 2 The blank shown has a uniform oversolution structure with a grain size of about 6 to 8 in all positions. The edges and center of the part are basically the same, and the grain size difference is usually no more than 1 level.

[0076] Example 6: The composition (mass fraction) of the γ'-strengthened nickel-based alloy used in this case is Cr 6.0%~9.0%, Co 14.0%~17.0%, W 5.0%~8.0%, Mo 1.0%~3.0%, Al 3.0%~5.0%, Ti 2.5%~4.5%, Nb 1.0%~3.5%, Zr 0.0%~0.06%, C 0.01%~0.1%, B 0.01%~0.3%, Hf 0.0%~0.5%, Ta 2.0%~4.5%, Fe 0.0%~1.0%, with the balance being Ni and other trace elements beneficial to high-temperature alloys and unavoidable trace or impurity elements.

[0077] The solid solution line of the γ'-strengthened nickel-based alloy used in this case is approximately 1180°C.

[0078] The alloy used in this case was in a hot isostatic pressing state before undergoing the following thermomechanical treatment, and thus possessed superplastic forming ability.

[0079] The raw billet of the alloy is processed into a suitable shape and size, and then subjected to thermomechanical treatment step by step.

[0080] The first thermomechanical treatment was performed at ~1100°C for no more than 0.01 s. -1 The strain rate is measured to obtain... Figure 3 The outline of the blank after the first thermomechanical treatment is shown in Figure 5. Figure 3 4 is a nickel alloy disc-type component.

[0081] The blank after the first thermomechanical heat treatment is subjected to subsolid heat treatment at ~1150°C.

[0082] The edge portion of the subsolid heat-treated disc blank is heated at ~1120°C for no more than 0.005 s. -1 The strain rate is subjected to a second thermomechanical treatment to obtain... Figure 3 The outline of the billet after the second thermomechanical treatment is shown in Figure 6.

[0083] The billet was subjected to solution heat treatment at ~1215°C for ~2 hours.

[0084] After cooling, it undergoes aging heat treatment between 800°C and 900°C.

[0085] Ultimately, we obtained the following: Figure 2 The blank shown is a nickel alloy disc, with part number 1 being a nickel alloy disc component. Figure 2 The grain size of the central region 2 of the part with a relatively small grain size is approximately level 4 to 5. Figure 2 The grain size of the edge region 3 of the part with a relatively large grain size is about 0 to 3, and the grain size of each part is uniform, with no abnormally large grains.

[0086] Due to the larger grain size, the material in the edge region of the part with a grain size of approximately 0 to 3 in this case exhibits excellent creep and environmental damage resistance. Its creep life at 850°C / 330MPa is 3 to 5 times that of the material in the center region of the part with a grain size of approximately 4 to 5.

[0087] It should be noted that the above process operations can be combined to varying degrees. For the sake of brevity, the implementation methods of various combinations will not be elaborated here. Those skilled in the art can flexibly adjust the order of the above operation steps or flexibly combine the above steps according to actual needs.

[0088] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should be covered within the protection scope of the present invention.

[0089] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A thermomechanical treatment method for nickel alloy disc-shaped parts, characterized in that, Includes the following steps: Obtain a nickel alloy billet and heat the nickel alloy billet to... ; The heated nickel alloy billet is subjected to a first thermomechanical process within the appropriate superplastic forming process range for the corresponding material to form a disc with an initial profile. The pre-processed blank with its initial contour is heated to... Perform the first heat treatment; The blank after the first heat treatment is heated to... Then, a second thermomechanical process is performed on the local part of the blank in the superplastic forming process range suitable for the corresponding material to form a blank that is close to the final contour. Heat the blank, which is close to the final shape, to... Perform a second heat treatment; Ultimately, disk blanks with different grain sizes in different regions are obtained.

2. The thermomechanical treatment method for a nickel alloy disc-shaped part according to claim 1, characterized in that, The nickel alloy billet is composed of a γ' phase-strengthened nickel-based superalloy.

3. The thermomechanical treatment method for a nickel alloy disc-shaped part according to claim 1, characterized in that, The The temperature is the superplastic forming temperature of the corresponding stage of the nickel alloy material, and the strain rate applied during the first thermomechanical processing is also within the superplastic forming process range of the corresponding stage of the processed nickel alloy material.

4. The thermomechanical treatment method for a nickel alloy disc-shaped part according to claim 1, characterized in that, The first thermomechanical processing includes at least one multi-fire forging process with similar temperatures and strain rates, and without any heat treatments above the thermomechanical processing temperature in between, to form a blank with an initial profile.

5. The thermomechanical treatment method for a nickel alloy disc-shaped part according to claim 1, characterized in that, The The temperature should not exceed 10°C above the solid solution line of the γ' phase in the processed nickel alloy.

6. The thermomechanical treatment method for a nickel alloy disc-shaped part according to claim 1, characterized in that, The temperature is the superplastic forming temperature of the corresponding stage of the processed nickel alloy material, and the strain rate applied during the second thermomechanical processing is also within the superplastic forming process range of the corresponding stage of the processed nickel alloy material.

7. The thermomechanical treatment method for a nickel alloy disc-shaped part according to claim 1, characterized in that, For the blank that is close to the final profile Perform a second heat treatment. It is higher than the solid solution line of the γ' phase in the selected nickel alloy.

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