Method for improving high temperature plasticity of GH4698 powder metallurgy parts and application

Abstract

The application belongs to the field of high-temperature alloy powder metallurgy, and particularly relates to a method for improving the high-temperature plasticity of a GH4698 powder metallurgical part and application thereof. The method comprises the following steps: preparing a GH4698 alloy blank by using GH4698 spherical powder, pretreating the GH4698 alloy blank to obtain a GH4698 alloy intermediate blank, and heat-treating the GH4698 alloy intermediate blank to obtain a GH4698 alloy part. The high-temperature coordinated deformation capacity of the obtained GH4698 alloy part is enhanced, and the room-temperature impact fracture of the alloy part is mainly caused by the internal fracture of the powder particles. Under the condition of 750 DEG C, the tensile strength is greater than 880 MPa, the yield strength is greater than 720 MPa, the elongation is greater than 10%, and the reduction of area is greater than 15%.

Description

Technical Field

[0001] This invention belongs to the field of high-temperature alloy powder metallurgy, specifically relating to a method and application for improving the high-temperature plasticity of GH4698 powder metallurgy parts. Background Technology

[0002] Nickel-based superalloys are widely used in aerospace, petrochemical, and nuclear power industries due to their excellent mechanical properties and good oxidation and corrosion resistance. GH4698, a Ni-Cr based precipitation-strengthened alloy, can be used at temperatures ranging from 750℃ to 800℃. The alloy exhibits high creep strength and tensile strength, good plasticity and overall performance, and long-term structural stability within the 550℃~800℃ range. It is suitable for manufacturing long-life, heavy-duty components such as engine drum shafts, compressor discs, guide vanes, turbine discs, load-bearing rings, and fasteners.

[0003] Currently, the mainstream manufacturing process for GH4698 alloy parts is as follows: first, bars are prepared using vacuum induction melting + vacuum arc remelting or vacuum induction melting + electroslag remelting; then, the bars are forged to form alloy billets; finally, the alloy billets undergo standard heat treatment of solution treatment and aging to obtain GH4698 alloy parts. However, the forged GH4698 billet contains a high density of dislocations, which often leads to abnormal grain growth during subsequent heat treatment, deteriorating the part's performance. Secondly, the non-uniform distribution of trace strengthening phases (such as carbides) during forging results in significant differences in transverse and longitudinal properties of the billet, which are inherited by the final part. Furthermore, the material utilization rate is extremely low in the production of some structural parts; for example, the material utilization rate of GH4698 drum parts for a certain type of engine is only about 15%.

[0004] To address the issues encountered in the forging process of GH4698 alloy, such as abnormal grain growth and trace strengthening phases (e.g., M... 23 The non-uniform distribution and low material utilization of C6 and other alloys can be addressed by using powder metallurgy to produce isotropic GH4698 parts (CN119876806A). However, in practice, it has been found that the high-temperature plasticity of powder metallurgy GH4698 parts is difficult to guarantee a suitable margin. Specifically, in GH4698 alloys prepared by powder metallurgy, the presence of carbon, titanium, and niobium, and a titanium-aluminum ratio exceeding 1.5, preferentially forms MC-type carbides and enriches them on the surface of powder particles, ultimately inheriting them in the form of original particle boundaries within the alloy. These original particle boundaries act as weak areas during high-temperature service and preferentially crack, ultimately leading to insufficient high-temperature plasticity margin in GH4698 alloy parts prepared by powder metallurgy, and directly affecting the service performance and reliability of the parts.

[0005] In view of this, the present invention is hereby proposed. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and propose a method and application for improving the high-temperature plasticity of GH4698 powder metallurgy parts. This method solves the problem of poor high-temperature plasticity encountered in the preparation of GH4698 alloy using existing powder metallurgy processes. Furthermore, it combines the advantages of powder metallurgy technology, such as the absence of abnormal grain growth and the presence of trace reinforcing phases (e.g., M... 23 With its uniform distribution of C6 and high material utilization, GH4698 can be further expanded to be used in powder metallurgy processes.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] On one hand, the present invention provides a method for improving the high-temperature plasticity of GH4698 powder metallurgy parts, including preparing GH4698 alloy billet using GH4698 spherical powder, pretreating the GH4698 alloy billet to obtain GH4698 alloy intermediate billet, and heat-treating the GH4698 alloy intermediate billet to obtain the target GH4698 alloy part.

[0009] See Figure 1 This includes the following steps:

[0010] Step 1: Prepare a conformal sleeve for the target part using carbon steel;

[0011] Step 2: After loading GH4698 spherical powder into the package, degassing and sealing treatment are carried out, followed by hot isostatic pressing and then furnace cooling to obtain GH4698 alloy billet.

[0012] Step 3: Pre-treat the sleeve containing the GH4698 alloy billet to obtain the GH4698 alloy intermediate billet;

[0013] Step 4: Heat treat the GH4698 alloy intermediate billet and the cladding, then remove the cladding by machining to obtain the target GH4698 alloy part.

[0014] Furthermore, in step 1, the thickness of the sheath is 5mm~10mm.

[0015] Furthermore, in step 3, the specific process of the pretreatment is as follows: heating to 950℃~1050℃, holding at that temperature for 1h~2h, and then furnace cooling.

[0016] Optionally, the pretreatment temperature can be 950℃, 980℃, 1000℃, 1020℃, or 1050℃, or it can be determined according to actual needs; the heat preservation time is 1h~2h, which can be 1h, 1.3h, 1.6h, 1.8h, or 2h, or it can be determined according to actual needs.

[0017] Specifically, by limiting the temperature, time and cooling method of the pretreatment, a stable and controllable Fe-O oxide layer with three characteristics is formed on the surface of the cladding. This oxide layer is composed of Fe2O3, Fe3O4 and FeO from the outside to the inside. These oxide layers have very low thermal conductivity (approximately 1-5 W / (m·K) from room temperature to high temperatures), effectively blocking the cooling of the part. By coordinating the pretreatment time and temperature, the thickness of the oxide layer can be controlled, thereby regulating the cooling process of the part in the later stages. Furthermore, the thermal conductivity of low-carbon steel is significantly higher than that of GH4698 alloy (the thermal conductivity of low-carbon steel is typically 45-60 W / (m·K) from room temperature to 300℃, approximately 35-45 W / (m·K) from 300℃ to 600℃, and approximately 30-40 W / (m·K) from 600℃ to 1000℃; while the thermal conductivity of GH4698 gradually increases from room temperature to 850℃, ranging from approximately 10 to 25 W / (m·K)). Therefore, the cooling between the cladding and the GH4698 part is not significantly affected or restricted by the presence of the cladding.

[0018] The pretreatment cooling method is furnace cooling, which can reduce the cracking and peeling of the oxide layer caused by thermal stress changes, and can ensure the integrity of the oxide layer and the tight bond between the oxide layer and the substrate.

[0019] Furthermore, in step 4, the heat treatment adopts a standard heat treatment process (compiled by the High Temperature Alloy Materials Branch of the Chinese Society for Metals, "Handbook of High Temperature Alloys in China", published by China Standards Press), specifically: (1110~1130)℃ × (8~8.5)h / AC + (990~1010)℃ × (4~4.5)h / AC + (765~785)℃ × (16~16.5)h / AC;

[0020] AC stands for Air Cooling.

[0021] On the other hand, the present invention also provides a GH4698 alloy part with excellent high-temperature plasticity, which is prepared based on the method described above for improving the high-temperature plasticity of GH4698 powder metallurgy parts.

[0022] Furthermore, the GH4698 alloy parts exhibit the following properties at 550°C: tensile strength > 1200 MPa, yield strength > 750 MPa, elongation > 25%, and reduction of area > 30%; at 650°C: tensile strength > 1150 MPa, yield strength > 740 MPa, elongation > 15%, and reduction of area > 20%; at 750°C: tensile strength > 880 MPa, yield strength > 720 MPa, elongation > 10%, and reduction of area > 15%; and at 800°C: tensile strength > 720 MPa, yield strength > 670 MPa, elongation > 15%, and reduction of area > 18%.

[0023] In another aspect, the present invention also provides an application of GH4698 alloy parts with excellent high-temperature plasticity as described above, for manufacturing long-life heavy-duty parts such as engine drum shafts, compressor discs, guide vanes, turbine discs, load-bearing rings and fasteners.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) The method of the present invention performs hot isostatic pressing on the shroud containing GH4698 spherical powder and adopts furnace cooling, which can effectively avoid the high internal dislocation density caused by large deformation in the forging process and rapid cooling, thereby fundamentally solving the problem of abnormal grain growth in the heat treatment process of GH4698 alloy.

[0026] (2) The method of the present invention pretreats the GH4698 alloy billet. By controlling the thickness of the oxide layer on the outer surface of the casing, and utilizing the low thermal conductivity of the oxide layer composed of Fe2O3, Fe3O4 and FeO, the heat exchange efficiency between the part and the air is effectively reduced. This promotes the further growth and cubic transformation of the large-size γ′ phase precipitated in the first stage of aging under lower cooling rates, and also promotes the increase of the volume fraction of the large-size γ′ phase. At the same time, based on obtaining a high volume fraction of large-size γ′ phase, the volume fraction of small-size γ′ phase is reduced, and the size is made smaller. Based on the above control, the size and volume fraction of the large-size γ′ phase are improved and the morphology is optimized, while the volume fraction of the small-size γ′ phase is reduced and its size is decreased, resulting in higher high-temperature plasticity and strength of the alloy. The resulting GH4698 alloy part has a uniform and stable microstructure and excellent mechanical properties.

[0027] (3) The high-temperature coordinated deformation ability between and within the powder particles of the GH4698 high-temperature alloy material obtained by the present invention is enhanced. The increase in the size, morphology and volume fraction of the large-size γ′ phase promotes the transformation of the interaction mechanism between dislocations and the γ′ phase during the stretching process from a cutting mechanism to a bypass mechanism, improves the coordination of dislocation movement, and promotes the alloy to have excellent plasticity. At the same time, the alloy strength is guaranteed by the dislocation cutting the small-size γ′ phase. Through microstructure optimization, the intragranular strength of the alloy is slightly reduced and the plasticity is improved. Under room temperature impact conditions, the impact load is transferred from the original particle boundaries to the grain boundaries and within the grains, ultimately resulting in an impact fracture surface dominated by internal fracture within the powder particles. Furthermore, at 550℃, the tensile strength is >1200MPa, yield strength >750MPa, elongation >25%, and reduction of area >30%; at 650℃, the tensile strength is >1150MPa, yield strength >740MPa, elongation >15%, and reduction of area >20%; at 750℃, the tensile strength is >880MPa, yield strength >720MPa, elongation >10%, and reduction of area >15%; and at 800℃, the tensile strength is >720MPa, yield strength >670MPa, elongation >15%, and reduction of area >18%. It is evident that the GH4698 alloy parts prepared by the method of this invention exhibit excellent high-temperature plasticity. Attached Figure Description

[0028] The accompanying drawings are incorporated in and form part of this specification, and together with the description serve to explain the principles of the invention.

[0029] 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, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a flowchart of the method for improving the high-temperature plasticity of GH4698 powder metallurgy parts according to the present invention;

[0031] Figure 2 The image shows the γ′ phase microstructure of the GH4698 alloy prepared in Example 1.

[0032] Figure 3 Microstructure of the γ′ phase of GH4698 alloy prepared by existing powder metallurgy process for Comparative Example 1;

[0033] Figure 4 The room temperature impact fracture characteristics of the GH4698 alloy prepared in Example 1;

[0034] Figure 5The room temperature impact fracture characteristics of GH4698 alloy prepared by existing powder metallurgy process are shown in Comparative Example 1. Detailed Implementation

[0035] Exemplary embodiments will be described in detail below. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples consistent with some aspects of the invention as detailed in the appended claims.

[0036] Example 1

[0037] This embodiment provides a method for improving the high-temperature plasticity of GH4698 powder metallurgy parts, specifically including the following steps:

[0038] Step 1: Prepare GH4698 spherical powder with a particle size of 53μm~150μm using the plasma rotating electrode method;

[0039] Step 2: Prepare a conformal sleeve for the target part using carbon steel, with a sleeve thickness of 5mm;

[0040] Step 3: After filling the package with powder, degassing, and sealing, hot isostatic pressing is performed, followed by furnace cooling to obtain GH4698 alloy billet.

[0041] Step 4: Heat the cladding containing the GH4698 alloy billet to 950°C, hold for 2 hours, and then furnace cool to obtain the GH4698 alloy intermediate billet.

[0042] Step 5: Heat treat the GH4698 alloy intermediate billet and the cladding, then remove the cladding by machining to obtain the target GH4698 alloy part.

[0043] Specifically, the heat treatment process is: 1110℃ × 8.5h / AC + 990℃ × 4.5h / AC + 765℃ × 16.5h / AC; where AC stands for Air Cooling.

[0044] This embodiment also provides a GH4698 alloy part with excellent high-temperature plasticity, obtained by the above method. The GH4698 alloy part has the following properties at 550℃: tensile strength > 1200MPa, yield strength > 750MPa, elongation > 25%, and reduction of area > 30%; at 650℃: tensile strength > 1150MPa, yield strength > 740MPa, elongation > 15%, and reduction of area > 20%; at 750℃: tensile strength > 880MPa, yield strength > 720MPa, elongation > 10%, and reduction of area > 15%; and at 800℃: tensile strength > 720MPa, yield strength > 670MPa, elongation > 15%, and reduction of area > 18%.

[0045] This embodiment also provides an application of GH4698 alloy parts with excellent high-temperature plasticity as described above, which are used to manufacture long-life heavy-duty parts such as engine drum shafts, compressor discs, guide vanes, turbine discs, load-bearing rings, and fasteners.

[0046] Comparative Example 1 (Existing process - source: "Exploration of Powder Metallurgy Forming of GH4698 High Temperature Alloy")

[0047] Step 1: Using GH4698 alloy rods as raw materials, the high-temperature alloy GH4698 powder with a particle size range of 53~150μm is obtained by plasma rotating electrode method and after sieving, electrostatic and magnetic separation to remove impurities.

[0048] Step 2: The GH4698 high-temperature alloy powder prepared in Step 1 is loaded into a pre-made sleeve. During the powder loading process, the pre-made sleeve is subjected to heating and vibration degassing treatment. After the vibration degassing treatment is completed, the sleeve is sealed and welded.

[0049] Step 3: The entire sheath after degassing and sealing in Step 2 is subjected to hot isostatic pressing under high temperature and high pressure conditions, wherein the temperature is 1200℃, the pressure is 150MPa, and the time is 4h.

[0050] Step 4: Remove the casing by machining to obtain powder metallurgy GH4698 billet;

[0051] Step 5: Perform solution treatment and aging heat treatment on the GH4698 billet obtained in Step 4 to obtain GH4698 alloy parts. The solution treatment and aging heat treatment process is as follows: First, hold at 1120℃ for 8 hours and then air cool; then, hold at 1000℃ for 4 hours and then air cool; finally, hold at 775℃ for 16 hours and then air cool.

[0052] The γ′ phase microstructure of the GH4698 alloy part obtained in Example 1 is shown in the figure below. Figure 2 As shown, from Figure 2 It can be seen that the GH4698 alloy parts prepared by this invention have two types of γ′ phases with different morphologies and sizes. The large-sized γ′ phase is nearly cubic, while the small-sized γ′ phase is nearly spherical. This is in contrast to the γ′ phase microstructure in the alloy under existing process conditions in Comparative Example 1. Figure 3In Example 1, the larger volume fraction and size of the large-size γ′ phase provide a prerequisite for hindering dislocations and promoting their movement around the large-size γ′ phase during high-temperature deformation. When dislocations migrate around the large-size γ′ phase, they form dislocation loops around it, resulting in a longer migration path, more moderate stress concentration, better coordination of dislocation movement, and less susceptibility to defects at the phase interface, thus ensuring excellent high-temperature plasticity of the alloy. Furthermore, dislocations directly cut the fine γ′ phase, requiring them to overcome coherent stresses between the γ′ phase and the matrix, interfacial energy, and resistance from the ordered structure within the γ′ phase. This greater resistance helps the alloy maintain high strength at high temperatures. The room-temperature impact fracture characteristics of the GH4698 alloy parts obtained in Example 1 are shown below. Figure 4 As shown, from Figure 4 It can be seen that under impact loading, cracks initiate and propagate from within the powder particles, and no interparticle fracture characteristics were observed. In contrast, the room temperature impact fracture characteristics of the alloy under existing process conditions in Comparative Example 1 (…) Figure 5 The fracture characteristics between powder particles are visible in the image, which indicates that the gaps between powder particles are thinner than the interiors of powder particles in the existing powder metallurgy process. Cracks can propagate rapidly between particles along the powder particle interface, which has an adverse effect on the safety and reliability of alloy parts.

[0053] Example 2

[0054] This embodiment provides a method for improving the high-temperature plasticity of GH4698 powder metallurgy parts, specifically including the following steps:

[0055] Step 1: Prepare GH4698 spherical powder with a particle size of 53μm~150μm using the plasma rotating electrode method;

[0056] Step 2: Prepare a conformal sleeve for the target part using carbon steel, with a sleeve thickness of 10mm;

[0057] Step 3: After filling the package with powder, degassing, and sealing, hot isostatic pressing is performed, followed by furnace cooling to obtain GH4698 alloy billet.

[0058] Step 4: Heat the cladding containing the GH4698 alloy billet to 1050°C, hold for 2 hours, and then furnace cool to obtain the GH4698 alloy intermediate billet.

[0059] Step 5: Heat treat the GH4698 alloy intermediate billet and the cladding, then remove the cladding by machining to obtain the target GH4698 alloy part.

[0060] Specifically, the heat treatment process is: 1120℃ × 8.2h / AC + 1000℃ × 4.3h / AC + 775℃ × 16.3h / AC.

[0061] Example 3

[0062] This embodiment provides a method for improving the high-temperature plasticity of GH4698 powder metallurgy parts, specifically including the following steps:

[0063] Step 1: Prepare GH4698 spherical powder with a particle size of 53μm~150μm using the plasma rotating electrode method;

[0064] Step 2: Prepare a conformal sleeve for the target part using carbon steel, with a sleeve thickness of 8mm;

[0065] Step 3: After filling the package with powder, degassing, and sealing, hot isostatic pressing is performed, followed by furnace cooling to obtain GH4698 alloy billet.

[0066] Step 4: Heat the cladding containing the GH4698 alloy billet to 1000℃, hold for 1 hour, and then furnace cool to obtain the GH4698 alloy intermediate billet.

[0067] Step 5: Heat treat the GH4698 alloy intermediate billet and the cladding, then remove the cladding by machining to obtain the target GH4698 alloy part.

[0068] Specifically, the heat treatment process is: 1130℃ ×8h / AC + 1010℃ ×4.5h / AC + 785℃ ×16.5h / AC.

[0069] Example 4

[0070] This embodiment provides a method for improving the high-temperature plasticity of GH4698 powder metallurgy parts, specifically including the following steps:

[0071] Step 1: Prepare GH4698 spherical powder with a particle size of 53μm~150μm using the plasma rotating electrode method;

[0072] Step 2: Prepare a conformal sleeve for the target part using carbon steel, with a sleeve thickness of 7mm;

[0073] Step 3: After filling the package with powder, degassing, and sealing, hot isostatic pressing is performed, followed by furnace cooling to obtain GH4698 alloy billet.

[0074] Step 4: Heat the cladding containing the GH4698 alloy billet to 985°C, hold for 1.5 hours, and then furnace cool to obtain the GH4698 alloy intermediate billet.

[0075] Step 5: Heat treat the GH4698 alloy intermediate billet and the cladding, then remove the cladding by machining to obtain the target GH4698 alloy part.

[0076] Specifically, the heat treatment process is: 1130℃ ×8h / AC + 1010℃ ×4.5h / AC + 785℃ ×16.5h / AC.

[0077] Comparative Example 2 (Existing process - source: "A method for preparing and applying a high-performance isotropic GH4698 drum")

[0078] Step 1: Using GH4698 alloy rods as raw materials, the high-temperature alloy GH4698 powder with a particle size range of 53~250μm is obtained by plasma rotating electrode method and after sieving, electrostatic and magnetic separation to remove impurities.

[0079] Step 2: At an ambient temperature of 440℃ and a vacuum degree of 3.5×10⁻⁶, -4 Under pressure, the GH4698 high-temperature alloy powder prepared in step 1 is loaded into a pre-made casing. During the powder loading process, the pre-made casing is subjected to heating and vibration degassing treatment. The vibration frequency is 25Hz and the amplitude is 1mm. After the vibration degassing treatment is completed, a sealing welding treatment is performed to make the pre-made casing containing the GH4698 high-temperature alloy powder form a sealed space.

[0080] Step 3: The entire encapsulation after degassing and sealing in Step 2 is subjected to cyclic hot isostatic pressing under high temperature and normal pressure + high temperature and high pressure conditions. The high temperature and normal pressure stage has a temperature of 1250℃, a pressure of 0.51MPa, and a time of 2 hours; the high temperature and high pressure stage has a temperature of 1190℃, a pressure of 200MPa, and a time of 4 hours. The high temperature and normal pressure stage is performed first, followed by the high temperature and high pressure stage. This process is repeated 3 times. After that, the encapsulation is cooled to 150℃ in the furnace.

[0081] Step 4: Remove the casing by machining to obtain the powder metallurgy GH4698 drum blank. The density of the alloy blank was measured to be 99.98%.

[0082] Step 5: Perform solution treatment and aging heat treatment on the GH4698 drum blank obtained in Step 4 to obtain the target drum shaft. The solution treatment and aging heat treatment process is as follows: First, hold at 1150℃ for 8 hours and then air cool; then, hold at 1000℃ for 4 hours and then air cool; finally, hold at 770℃ for 16 hours and then air cool.

[0083] In Examples 1-4 above, step 3 specifically includes: preparing the GH4698 spherical powder under a vacuum degree ≤1×10⁻⁶. -4 The package is loaded into the casing under the condition of Pa; the casing is subjected to hot isostatic pressing and then cooled in the furnace; the hot isostatic pressing process is as follows: the temperature is raised to 1190℃~1200℃, the pressure is raised to 150MPa~180MPa with the temperature, and the temperature and pressure are maintained for 3h~4h.

[0084] To better illustrate the beneficial effects of the present invention, the GH4698 alloy parts obtained in Examples 1-4 and Comparative Examples 1-2 were subjected to high-temperature tensile tests at 550℃, 650℃, 750℃, and 800℃, respectively, with reference to GB / T 228.2-2015; the test results are shown in Table 1 below:

[0085] Table 1. High-Temperature Tensile Properties Test Results of GH4698 Alloy Parts

[0086]

[0087] As shown in Table 1, the GH4698 alloy parts prepared by this invention exhibit the following properties at 550℃: tensile strength > 1200 MPa, yield strength > 750 MPa, elongation > 25%, and reduction of area > 30%; at 650℃: tensile strength > 1150 MPa, yield strength > 740 MPa, elongation > 15%, and reduction of area > 20%; at 750℃: tensile strength > 880 MPa, yield strength > 720 MPa, elongation > 10%, and reduction of area > 15%; and at 800℃: tensile strength > 720 MPa, yield strength > 670 MPa, elongation > 15%, and reduction of area > 18%. The high-temperature plasticity at 750℃ is significantly better than that of existing processes, while the high-temperature strength is essentially equivalent to that of existing processes.

[0088] In summary, the GH4698 alloy parts prepared by this invention exhibit excellent strength and ductility at high temperatures (550℃~800℃). Firstly, high strength can reduce the ratio of load to material strength, improving safety; secondly, high ductility allows for better deformation performance before material failure, thereby improving the reliability of the alloy in service.

[0089] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention.

[0090] It should be understood that the present invention is not limited to the content already described above, and various modifications and changes can be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims

1. A method for improving the high-temperature plasticity of GH4698 powder metallurgy parts, characterized in that, The process includes preparing GH4698 alloy billet using GH4698 spherical powder, pretreating the GH4698 alloy billet to obtain GH4698 alloy intermediate billet, and heat-treating the GH4698 alloy intermediate billet to obtain the target GH4698 alloy part. Includes the following steps: Step 1: Prepare a conformal sleeve for the target part using carbon steel, with a sleeve thickness of 5mm~10mm; Step 2: After loading GH4698 spherical powder into the package, degassing and sealing treatment are carried out, followed by hot isostatic pressing and then furnace cooling to obtain GH4698 alloy billet. Step 3: Pre-treat the sleeve containing the GH4698 alloy billet to obtain the GH4698 alloy intermediate billet; The specific process of the pretreatment is as follows: heat to 950℃~1050℃, keep at that temperature for 1h~2h, and then cool in the furnace. Step 4: Heat treat the GH4698 alloy intermediate billet and the cladding, then remove the cladding by machining to obtain the target GH4698 alloy part.

2. The method for improving the high-temperature plasticity of GH4698 powder metallurgy parts according to claim 1, characterized in that, In step 4, the heat treatment adopts a standard heat treatment process, specifically: (1110~1130)℃ × (8~8.5)h / AC + (990~1010)℃ × (4~4.5)h / AC + (765~785)℃ × (16~16.5)h / AC; where AC represents air cooling.

3. A GH4698 alloy part with excellent high-temperature plasticity, characterized in that, It was prepared based on the method for improving the high-temperature plasticity of GH4698 powder metallurgy parts according to any one of claims 1 to 2.

4. The GH4698 alloy part with excellent high-temperature plasticity according to claim 3, characterized in that, The GH4698 alloy parts exhibit the following properties at 550℃: tensile strength > 1200 MPa, yield strength > 750 MPa, elongation > 25%, and reduction of area > 30%; at 650℃: tensile strength > 1150 MPa, yield strength > 740 MPa, elongation > 15%, and reduction of area > 20%; at 750℃: tensile strength > 880 MPa, yield strength > 720 MPa, elongation > 10%, and reduction of area > 15%; and at 800℃: tensile strength > 720 MPa, yield strength > 670 MPa, elongation > 15%, and reduction of area > 18%.

5. An application of the GH4698 alloy with excellent high-temperature plasticity as described in claim 3 or 4, characterized in that, Used to manufacture engine drum shafts, compressor discs, guide vanes, turbine discs, load-bearing rings, and fasteners.

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