Nickel-based wrought superalloy and preparation method thereof

Abstract

The invention discloses a nickel-based wrought superalloy and a preparation method thereof, and belongs to the technical field of superalloy design and preparation. The nickel-based wrought superalloy is obtained by optimizing component design, reasonably controlling the contents of Ti, Al, Nb and Ta and adding rare earth elements in a specific range, preparing an alloy ingot by adopting a vacuum induction and electroslag remelting process, carrying out specific multi-stage homogenization treatment on the ingot, cooling, alternately carrying out upsetting and drawing-out, then carrying out radial forging, and finally carrying out heat treatment to obtain the nickel-based wrought superalloy. The nickel-based wrought superalloy provided by the invention has a uniform and fine grain structure, the tensile strength of the nickel-based wrought superalloy is greater than or equal to 1400 MPa and the yield strength of the nickel-based wrought superalloy is greater than or equal to 1200 MPa at room temperature, and the tensile strength of the nickel-based wrought superalloy is greater than or equal to

Description

Technical Field

[0001] This invention relates to the field of high-temperature alloy design and preparation technology, and to a nickel-based wrought high-temperature alloy and its preparation method, particularly a nickel-based wrought high-temperature alloy with excellent high-temperature strength and good hot working properties and its preparation method. Background Technology

[0002] With the rapid development of the aerospace industry, higher requirements have been placed on the temperature resistance of hot-end components of aero engines, especially key components such as turbine disks and blades. Currently, commercially available alloys with relatively high temperature resistance include GH4065A and GH4151, but their maximum temperature resistance can only reach 750℃, which is insufficient to meet the requirements of next-generation aero engines for operating temperatures of 800℃ and above.

[0003] The main problems existing in the prior art include:

[0004] (1) The contradiction between strength and processing performance. In order to improve high-temperature strength, it is usually necessary to increase the content of γ′ phase forming elements (Al, Ti, etc.), but this will lead to a significant deterioration in the hot working performance of the alloy. A high content of γ′ phase makes the alloy prone to intergranular cracking during hot working, making it difficult to engineer.

[0005] (2) Limitations of rare earth element application. Although existing technologies have attempted to improve the performance of high-temperature alloys by adding rare earth elements, these studies mainly focus on single-crystal or cast high-temperature alloys, improving performance by purifying the alloy, strengthening grain boundaries, and improving oxidation resistance. However, in difficult-to-deform high-temperature alloys, how to coordinate the strength of grain boundaries and intragranular areas with rare earth elements, while improving the temperature resistance and hot working performance, remains a technical challenge.

[0006] Therefore, there is an urgent need to develop a new type of nickel-based wrought high-temperature alloy that can improve the temperature resistance to over 800℃ and has good hot working properties to meet the design requirements of advanced aero-engines. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention provides a nickel-based wrought superalloy and its preparation method. By optimizing the composition design, particularly by rationally controlling the contents of Ti, Al, Nb, and Ta and adding a specific range of rare earth elements, the alloy maintains excellent high-temperature strength (800℃ and above) while possessing good hot working properties.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] The first aspect of this invention provides a nickel-based wrought superalloy, the chemical composition of which, by weight percentage, includes: C: ≤0.08wt%; Cr: 9wt%~13wt%; Co: 17wt%~21wt%; W: 3wt%~5wt%; Mo: 2wt%~4wt%; Al: 2wt%~4wt%; Ti: 2wt%~3.5wt%; Nb: 1wt%~3wt%; Zr: 0.01wt%~0.1wt%; B: ≤0.04wt%; Ta: 4wt%~6wt%; Hf: ≤0.6wt%; Ce: ≤0.01%; the balance being Ni and unavoidable impurity elements.

[0010] Preferably, the chemical composition of the nickel-based wrought superalloy includes: C: 0.02wt%~0.07wt%; Cr: 10wt%~12.5wt%; Co: 17wt%~21wt%; W: 3wt%~5wt%; Mo: 2.5wt%~3.5wt%; Al: 2.5wt%~3.5wt%; Ti: 2.5wt%~3wt%; Nb: 1.5wt%~2.5wt%; Zr: 0.03wt%~0.06wt%; B: 0.01wt%~0.02wt%; Ta: 4.5wt%~5.5wt%; Hf: 0.2wt%~0.4wt%; Ce: 0.003wt%~0.010%; the balance being Ni and unavoidable impurity elements.

[0011] The high-temperature nickel-based alloy has a tensile strength ≥1400MPa and a yield strength ≥1200MPa at room temperature, and a tensile strength ≥1000MPa and a yield strength ≥800MPa at 800℃.

[0012] A second aspect of the present invention provides a method for preparing the nickel-based wrought superalloy, comprising the following steps:

[0013] (1) The alloy ingots were smelted using a combination of vacuum induction melting and electroslag remelting.

[0014] (2) After multi-stage heat preservation and homogenization treatment at 1130℃~1220℃, the furnace is cooled to 1000℃ at a cooling rate of no more than 10℃ / h, and then slowly cooled to below 100℃ before being taken out of the furnace.

[0015] (3) After heating and holding at 1100℃~1150℃, the billet is forged by upsetting and drawing, and then the diameter is forged after heating and holding at 1100℃~1150℃.

[0016] (4) Heat treatment of finished product.

[0017] As a preferred technical solution:

[0018] The multi-stage heat preservation and homogenization process in step (2) is as follows: cold furnace loading, heating with the furnace, heating to 1130℃~1140℃ in 4-5 hours, heat preservation for more than 15 hours, then heating to 1200℃~1220℃, heat preservation for more than 50 hours, then furnace cooling to 1000℃ at a cooling rate of no more than 10℃ / h, and then furnace cooling to below 100℃ before being removed from the furnace.

[0019] The upsetting and drawing process in step (3) is as follows: upsetting and drawing are carried out alternately. The deformation amount of the first upsetting is controlled at 10%~20% using a fast forging machine, and the deformation amount of the second drawing is controlled at 10%~20%. After that, the deformation amount of each drawing is controlled at 20%~50%.

[0020] The radial forging process is as follows: the radial forging machine is used to heat process the product to the finished size in one heat, and the amount of surface deformation is controlled within 20%~50%.

[0021] Compared with the prior art, the present invention has the following significant advantages:

[0022] This invention, through the design of chemical composition, ensures that the reinforcing phase in the alloy retains good stability at 800℃, thus guaranteeing that the alloy can maintain high strength at this temperature.

[0023] This invention provides a reasonable preparation method that solves the problem of difficult deformation of nickel-based alloys with added high strengthening elements, and obtains a uniform grain structure and high strength at 800℃. Attached Figure Description

[0024] Figure 1 The microstructure of the alloy obtained after homogenization heat treatment in Example 1 of this invention;

[0025] Figure 2 Microstructure of the alloy rod obtained in Example 1 of this invention;

[0026] Figure 3 The microstructure of the alloy obtained after homogenization treatment in Comparative Example 3 of this invention;

[0027] Figure 4 Comparative Example 3 of this invention shows the forging crack structure. Detailed Implementation

[0028] This invention provides a nickel-based wrought superalloy, comprising, by weight percentage: C ≤0.08wt%, Cr 9wt%~13wt%, Co 17wt%~21wt%, W 3wt%~5wt%, Mo 2wt%~4wt%, Al 2wt%~4wt%, Ti 2wt%~3.5wt%, Nb 1wt%-3wt%, Zr 0.01wt%~0.1wt%, B ≤0.04wt%, Ta 4wt%~6wt%, Hf ≤0.6wt%, Ce ≤0.01wt%, with the balance being Ni and unavoidable impurity elements; preferably, C 0.02wt%~0.07wt%, Cr 10wt%~12.5wt%, Co 17wt%~21wt%, W 3wt%~5wt%, Mo 2.5wt%~3.5wt%, Al 2.5wt%-3.5wt%, Ti 2.5wt%~3wt%, Nb 1.5wt%~2.5wt%, Zr 0.03wt%~0.06wt%, B 0.01wt%~0.02wt%, Ta 4.5wt%~5.5wt%, Hf 0.2wt%~0.4wt%, Ce 0.003wt%~0.010wt%, with the balance being Ni and unavoidable impurity elements.

[0029] The nickel-based wrought superalloy provided by this invention has a tensile strength ≥1400MPa and a yield strength ≥1200MPa at room temperature, and a tensile strength ≥1000MPa and a yield strength ≥800MPa at 800℃.

[0030] The compositional design of the nickel-based wrought superalloy provided by this invention is as follows: Using Ni-Co-Cr as the matrix, Ni maintains a stable austenitic structure at high temperatures; Co reduces stacking fault energy, promotes twin formation, and improves the alloy's high-temperature strength; Cr forms a chromium oxide protective layer on the alloy surface during service, improving the alloy's resistance to high-temperature oxidation. W and Mo are solid solution strengthening elements, which can cause matrix lattice expansion and improve alloy strength. Furthermore, W can dissolve in the γ′ phase, altering the lattice constant and mismatch degree between the γ and γ′ phases. Al, Ti, Nb, and Ta are age-hardening elements, designed to form a stable strengthening phase γ′ (Ni3(Al,Ti)) at 800℃. Among these, the ultra-high content of Ta (4wt%-6wt%) is particularly crucial, as it can dissolve extensively in the γ′ phase, significantly enhancing its high-temperature stability and strengthening effect. The alloy also contains trace elements such as Hf, B, Zr, and Ce. In addition to improving the precipitation state of primary carbides, the addition of Hf can also dissolve in the γ′ phase, thereby enhancing the strengthening effect of the γ′ phase. Ce, B, and Zr segregate at grain boundaries, which can improve grain boundary strength and inhibit the initiation and propagation of grain boundary cracks during hot working. Ce can also dissolve in the γ′ phase, thereby improving the high-temperature stability of the γ′ phase.

[0031] The present invention also provides a method for preparing the above-mentioned nickel-based wrought superalloy, comprising the following steps:

[0032] (1) The alloy ingots were smelted using a combination of vacuum induction melting and electroslag remelting.

[0033] (2) After the ingot is heated and homogenized in multiple stages at 1130℃~1220℃, it is slowly cooled in the furnace. Specifically, the furnace is charged with cold material, and the furnace is heated. After 4h~5h, the temperature is raised to 1130℃~1140℃ and held for more than 15h. Then the temperature is raised to 1200℃~1220℃ and held for more than 50h. Then the furnace is cooled to 1000℃ at a cooling rate of no more than 10℃ / h. After that, it is slowly cooled in the furnace to below 100℃ before being taken out of the furnace.

[0034] (3) After the ingot is heated and held at 1100℃~1150℃, it is alternately upset and drawn. Then, it is heated and held at 1100℃~1150℃ and then radial forging is performed. Specifically, the deformation amount of the first upset is controlled at 10%~20% using a high-speed forging machine, the deformation amount of the second drawing is controlled at 10%~20%, and the deformation amount of each subsequent drawing is controlled at 20%~50%. The final forging temperature of each drawing is not lower than 1000℃. The radial forging process is as follows: the radial forging machine is used to heat process the finished product size in one drawing, and the deformation amount of the surface is controlled at 20%~50%.

[0035] (4) Heat treatment of finished product.

[0036] This invention provides a process using vacuum induction followed by electroslag remelting to improve problems such as segregation and porosity caused by high content of strengthening elements. Because the alloy contains high levels of strongly segregating elements such as Al, Ti, Nb, Ta, Hf, Mo, and W, primary blocky phases and significant element segregation inevitably occur during the solidification process of the ingot. The primary low-melting-point phases with melting points below the forging temperature and the significant element segregation severely deteriorate the alloy's hot working properties. Therefore, a specific homogenization treatment is needed to eliminate the primary low-melting-point phases with melting points below the forging temperature and dendritic segregation of elements. Holding at 1130℃~1140℃ eliminates the primary low-melting-point precipitates rich in Mo, Hf, and Nb formed in the as-cast microstructure. Holding at 1200℃~1220℃ promotes the uniform diffusion of segregated elements. Slow cooling after holding promotes the formation of γ′ phase with an average size of 3μm~7μm, improving the hot working properties of the alloy. The hot forging temperature is selected below the γ′ phase dissolution temperature (1160℃). The initial state of the alloy is a coarse-grained microstructure with a grain size of grade 0 or higher. The first two forgings induce the alloy through a small deformation of 10%-20%. A certain proportion of dynamic recrystallization occurs, which triggers static recrystallization during the subsequent heat preservation process. Furthermore, due to the pinning of grain boundaries by the γ′ phase, abnormal grain growth during the heat preservation process can be suppressed. The first two heat treatments result in a grain structure with most grain sizes below grade 5, which significantly improves the hot working properties of the alloy. Subsequent heat treatments increase the deformation amount to 20%~50%, allowing the alloy to undergo complete recrystallization during hot deformation, resulting in a uniform and fine grain structure. Finally, combined with the heat treatment of the finished product, the alloy is guaranteed to obtain excellent high-temperature mechanical properties.

[0037] This invention controls the ingot to be cooled to 1000°C at a rate not exceeding 10°C / h after multi-stage heat preservation and homogenization, thereby obtaining a large-sized γ′ phase. When the ingot temperature drops below 1000°C, the cooling rate is no longer controlled during furnace cooling in order to prevent thermal cracking caused by high-temperature furnace exit.

[0038] The present invention will be further described in detail below with reference to embodiments, but the implementation of the present invention is not limited thereto.

[0039] The composition of the nickel-based superalloys prepared in Examples 1-4 and the comparative examples of the present invention is shown in Table 1.

[0040] Table 1 Alloy composition (wt%) of Examples 1-4 and Comparative Examples 1-4.

[0041] ;

[0042] Example 1:

[0043] This embodiment provides a nickel-based superalloy and its preparation method. The composition of the alloy is shown in Table 1.

[0044] The method for preparing nickel-based superalloys provided in this embodiment includes the following steps:

[0045] S1. According to the alloy composition in Table 1, the alloy ingot is obtained by vacuum induction + electroslag remelting process.

[0046] S2. The smelted ingot is charged into a cold furnace and heated to 1140℃ in the furnace for 4 hours. It is then held at 1140℃ for 15 hours, then heated to 1200℃ and held for 50 hours. It is then furnace cooled to 1000℃ at a cooling rate of 6℃ / h, and then slowly cooled to below 100℃ before being removed from the furnace. A large number of large γ′ phases are observed to precipitate in the alloy, with an average size of about 5μm. Figure 1 (As shown).

[0047] S3. After homogenization, the ingot is loaded into the furnace at a temperature below 500℃ and slowly heated to 1150℃ for holding. Based on the bar diameter, the holding time for each heat should be ≥0.8 min / mm. Subsequent heats are held at temperatures of 1150℃, 1140℃, 1140℃, 1130℃, and 1100℃, with a holding time of at least 1 hour. Using a high-speed forging mill, the upsetting deformation is 12.6% for the first heat, 12.2% for the second heat (drawing and reducing surface area), 35.6% for the third heat, 35.3% for the fourth heat, 44.5% for the fifth heat, and 45.6% for the sixth heat.

[0048] After polishing the surface of the forged billet to remove microcracks, it is loaded into the furnace at a temperature below 500℃ and slowly heated to 1150℃ and held there. The holding time per heat is ≥0.8 min / mm, calculated based on the billet diameter. The billet is then hot-processed to the finished size in a single heat using a radial forging mill, with the surface deformation controlled at 49.6%.

[0049] S4. Finished product heat treatment. After radial forging, the product undergoes solution treatment at 1100℃~1150℃ for 1h~2h, followed by air cooling and aging treatment at 750℃~850℃ for 8h~16h. The microstructure is a fine-grained microstructure with uniform grain size of grade 11~12. Figure 2 As shown in Table 2), the room temperature tensile and 800℃ tensile properties were tested, and the results are shown in Table 2.

[0050] Example 2:

[0051] This embodiment provides a nickel-based superalloy and its preparation method. The composition of the alloy is shown in Table 1.

[0052] The method for preparing nickel-based superalloys provided in this embodiment includes the following steps:

[0053] S1. According to the alloy composition in Table 1, the alloy ingot is obtained by vacuum induction + electroslag remelting process.

[0054] S2. The smelted ingot is charged into a cold furnace and heated to 1140℃ in the furnace for 4 hours. It is then held at 1140℃ for 15 hours, then heated to 1200℃ and held for 50 hours. It is then cooled to 1000℃ in the furnace at a cooling rate of 6℃ / h. After that, it is slowly cooled to below 100℃ in the furnace and then taken out of the furnace. It can be seen that a large number of large γ′ phases are precipitated in the alloy, with an average size of about 5μm.

[0055] S3. After homogenization, the ingot is loaded into the furnace at a temperature below 500℃ and slowly heated to 1150℃ for holding. Based on the bar diameter, the holding time for each heat should be ≥0.8 min / mm. Subsequent heats are held at temperatures of 1150℃, 1140℃, 1140℃, 1130℃, and 1100℃, with a holding time of at least 1 hour. Using a high-speed forging mill, the upsetting deformation is 12.6% for the first heat, 12.2% for the second heat (drawing and reducing surface area), 35.6% for the third heat, 35.3% for the fourth heat, 44.5% for the fifth heat, and 45.6% for the sixth heat.

[0056] After polishing the surface of the forged billet to remove microcracks, it is loaded into the furnace at a temperature below 500℃ and slowly heated to 1150℃ and held there. The holding time per heat is ≥0.8 min / mm, calculated based on the billet diameter. The billet is then hot-processed to the finished size in a single heat using a radial forging mill, with the surface deformation controlled at 49.6%.

[0057] S4. Finished product heat treatment. After radial forging, the product is solution treated at 1100℃~1150℃ for 1h~2h, then air-cooled and aged at 750℃~850℃ for 8h~16h. The microstructure is a fine-grained microstructure with uniform grain size of grade 11~12. The room temperature tensile and 800℃ tensile properties are tested, and the results are shown in Table 2.

[0058] Example 3:

[0059] This embodiment provides a nickel-based superalloy and its preparation method. The composition of the alloy is shown in Table 1.

[0060] The method for preparing nickel-based superalloys provided in this embodiment includes the following steps:

[0061] S1. According to the alloy composition in Table 1, the alloy ingot is obtained by vacuum induction + electroslag remelting process.

[0062] S2. The smelted ingot is charged into a cold furnace and heated to 1140℃ in the furnace for 4 hours. It is then held at 1140℃ for 15 hours, then heated to 1200℃ and held for 50 hours. It is then cooled to 1000℃ in the furnace at a cooling rate of 6℃ / h. After that, it is slowly cooled to below 100℃ in the furnace and then taken out of the furnace. It can be seen that a large number of large γ′ phases are precipitated in the alloy, with an average size of about 5μm.

[0063] S3. After homogenization, the ingot is loaded into the furnace at a temperature below 500℃ and slowly heated to 1150℃ for holding. Based on the bar diameter, the holding time for each heat should be ≥0.8 min / mm. Subsequent heats are held at temperatures of 1150℃, 1140℃, 1140℃, 1130℃, and 1100℃, with a holding time of at least 1 hour. Using a high-speed forging mill, the upsetting deformation is 12.6% for the first heat, 12.2% for the second heat (drawing and reducing surface area), 35.6% for the third heat, 35.3% for the fourth heat, 44.5% for the fifth heat, and 45.6% for the sixth heat.

[0064] After polishing the surface of the forged billet to remove microcracks, it is loaded into the furnace at a temperature below 500℃ and slowly heated to 1150℃ and held there. The holding time per heat is ≥0.8 min / mm, calculated based on the billet diameter. The billet is then hot-processed to the finished size in a single heat using a radial forging mill, with the surface deformation controlled at 49.6%.

[0065] S4. Finished product heat treatment. After radial forging, the product is solution treated at 1100℃~1150℃ for 1h~2h, then air-cooled and aged at 750℃~850℃ for 8h~16h. The microstructure is a fine-grained microstructure with uniform grain size of grade 11~12. The room temperature tensile and 800℃ tensile properties are tested, and the results are shown in Table 2.

[0066] Example 4:

[0067] This embodiment provides a nickel-based superalloy and its preparation method. The composition of the alloy is shown in Table 1.

[0068] The method for preparing nickel-based superalloys provided in this embodiment includes the following steps:

[0069] S1. According to the alloy composition in Table 1, the alloy ingot is obtained by vacuum induction + electroslag remelting process.

[0070] S2. The smelted ingot was charged into a cold furnace and heated to 1130℃ in the furnace for 5 hours. It was then held at 1130℃ for 25 hours, then heated to 1220℃ and held for 50 hours. Finally, it was furnace cooled to 1000℃ at a rate of 10℃ / h, and then slowly cooled to below 100℃ before being removed from the furnace. A γ′ phase with an average size of approximately 5 μm was also obtained.

[0071] S3. After homogenization, the ingot is loaded into the furnace at a temperature below 500℃ and slowly heated to 1150℃ for holding. Based on the bar diameter, the holding time for each heat should be ≥0.8 min / mm. Subsequent heats are held at temperatures of 1150℃, 1140℃, 1140℃, 1130℃, and 1100℃, with a holding time of at least 1 hour. Using a high-speed forging mill, the upsetting deformation is 12.6% for the first heat, 12.2% for the second heat (drawing and reducing surface area), 35.6% for the third heat, 35.3% for the fourth heat, 31.3% for the fifth heat, and 32.2% for the sixth heat.

[0072] After polishing the surface of the forged billet to remove microcracks, it is loaded into the furnace at a temperature below 500℃ and slowly heated to 1100℃ and held at that temperature. The holding time per heat is ≥0.8 min / mm, calculated based on the billet diameter. The billet is then hot-processed to the finished size in a single heat using a radial forging mill, with the surface deformation controlled within 40.2%.

[0073] S4. Finished product heat treatment. The finished product after radial forging underwent the same heat treatment as in Example 1, resulting in a fine-grained structure with a grain size of 11-12. The tensile properties at room temperature and at 800℃ were tested, and the results are shown in Table 2.

[0074] Comparative Examples 1-2:

[0075] Comparative Examples 1 and 2 respectively provide a high-temperature nickel-based alloy and its preparation method. The composition of the alloy is shown in Table 1. The preparation process and parameters of the alloy are the same as those in Example 1, except that the alloy composition is different. The room temperature tensile and 800℃ tensile properties of the alloy were tested, and the results are shown in Table 2. The results show that the strength of both is lower than that of the examples.

[0076] Comparative Example 3:

[0077] This comparative example provides a high-temperature nickel-based alloy and its preparation method, wherein the composition of the alloy is shown in Table 1.

[0078] The comparative example provides a method for preparing the alloy, which includes the following steps:

[0079] S1. According to the alloy composition in Table 1, the alloy ingot is obtained by vacuum induction + electroslag remelting process.

[0080] S2. The smelted ingot is charged into a cold furnace and heated to 1140℃ in the furnace for 4 hours. It is then held at 1140℃ for 15 hours, then heated to 1200℃ and held for 50 hours. Finally, it is cooled in the furnace to below 100℃ and removed from the furnace (the cooling rate from 1200℃ to 1000℃ is approximately 50℃ / h). Under these cooling conditions, dense, fine strengthening phases with a size of less than 1μm precipitate in the alloy. Figure 3 ).

[0081] S4. The homogenized ingot is loaded into the furnace at a temperature below 500℃ and slowly heated to 1150℃ and held there. The holding time per heat is ≥0.8 min / mm, calculated based on the bar diameter. Cracking occurred during the first upsetting process when the deformation did not reach 10%, making subsequent forging impossible. The microstructure analysis results show that ( Figure 4 Cracks initiate in the partially recrystallized region at the original coarse grain boundaries. This is because the small-sized γ′ phase significantly increases the deformation resistance of the matrix, making it impossible for the grains and grain boundaries to deform in tandem during hot deformation, and stress tends to concentrate at the grain boundaries.

[0082] Comparative Example 4:

[0083] This comparative example provides a high-temperature nickel-based alloy and its preparation method, wherein the composition of the alloy is shown in Table 1.

[0084] The comparative example provides a method for preparing the alloy, which includes the following steps:

[0085] S1. According to the alloy composition in Table 1, the alloy ingot is obtained by vacuum induction + electroslag remelting process.

[0086] S2. The smelted ingot is charged into the cold furnace and heated to 1140℃ in the furnace for 4 hours. It is then held at 1140℃ for 15 hours, then heated to 1200℃ and held for 50 hours. It is then cooled to 1000℃ in the furnace at a rate of 6℃ / h, and then slowly cooled to below 100℃ before being unloaded.

[0087] S3. After homogenization, the ingot is loaded into the furnace at a temperature below 500℃ and slowly heated to 1180℃ and held there. The holding time per heat is ≥0.8 min / mm, calculated based on the bar diameter. Cracking occurs during the first upsetting process if the deformation does not reach 10%, making subsequent forging impossible. Cracks initiate at the original coarse grain boundaries because the forging temperature is higher than the melting temperature of the γ′ phase, resulting in no γ′ phase reinforcement at the grain boundaries, making them weak areas.

[0088] Table 2. Summary of alloy properties obtained from different embodiments and comparative examples;

[0089] ;

[0090] The results of the above embodiments demonstrate that, through optimized composition design and preparation process, the present invention has successfully developed a nickel-based wrought superalloy with excellent high-temperature strength and good hot working properties, which is particularly suitable for manufacturing key hot-end components such as turbine disks and blades for aero-engines.

Claims

1. A nickel-based wrought superalloy, characterized in that, The chemical composition, by weight percentage, includes: C: ≤0.08wt%; Cr: 9wt%~13wt%; Co: 17wt%~21wt%; W: 3wt%~5wt%; Mo: 2wt%~4wt%; Al: 2wt%~4wt%; Ti: 2wt%~3.5wt%; Nb: 1wt%~3wt%; Zr: 0.01wt%~0.1wt%; B: ≤0.04wt%; Ta: 4wt%~6wt%; Hf: ≤0.6wt%; Ce: ≤0.01%; the balance being Ni and unavoidable impurity elements.

2. The nickel-based wrought superalloy according to claim 1, characterized in that, The chemical composition of the nickel-based wrought superalloy, by weight percentage, includes: C: 0.02wt%~0.07wt%; Cr: 10wt%~12.5wt%; Co: 17wt%~21wt%; W: 3wt%~5wt%; Mo: 2.5wt%~3.5wt%; Al: 2.5wt%~3.5wt%; Ti: 2.5wt%~3wt%; Nb: 1.5wt%~2.5wt%; Zr: 0.03wt%~0.06wt%; B: 0.01wt%~0.02wt%; Ta: 4.5wt%~5.5wt%; Hf: 0.2wt%~0.4wt%; Ce: 0.003wt%~0.010%; the balance being Ni and unavoidable impurity elements.

3. A nickel-based wrought superalloy according to claim 1 or 2, characterized in that, The nickel-based wrought superalloy has a tensile strength ≥1400MPa and a yield strength ≥1200MPa at room temperature, and a tensile strength ≥1000MPa and a yield strength ≥800MPa at 800℃.

4. The method for preparing the nickel-based wrought superalloy according to claim 1 or 2, characterized in that, Includes the following steps: S1. Alloy ingots are smelted using a combination of vacuum induction melting and electroslag remelting. S2. After multi-stage heat preservation and homogenization treatment at 1130℃~1220℃, the furnace is cooled to 1000℃ at a cooling rate of no more than 10℃ / h, and then cooled to below 100℃ before being taken out of the furnace. S3. After heating and holding at 1100℃~1150℃, perform upsetting and forging of the billet, and then perform radial forging after heating and holding at 1100℃~1150℃. S4. Finished product heat treatment.

5. The method for preparing a nickel-based wrought superalloy according to claim 4, characterized in that, In S2, the multi-stage heat preservation and homogenization process is as follows: cold furnace charging, heating with the furnace, heating to 1130℃~1140℃ in 4-5 hours, holding for more than 15 hours, then heating to 1200℃~1220℃, holding for more than 50 hours, then cooling to 1000℃ in the furnace at a cooling rate not exceeding 10℃ / h, and then cooling to below 100℃ before being removed from the furnace.

6. The method for preparing a nickel-based wrought superalloy according to claim 4, characterized in that, In S3, the upsetting and drawing forging process is as follows: upsetting and drawing are carried out alternately. The deformation amount of the first upsetting is controlled at 10%~20% using a fast forging machine, the deformation amount of the second drawing is controlled at 10%~20%, and the deformation amount of each subsequent drawing is controlled at 20%~50%.

7. The method for preparing a nickel-based wrought superalloy according to claim 4, characterized in that, In S3, the radial forging process is as follows: the radial forging machine is used to heat process the product to the finished size in one heat, and the surface deformation is controlled within 20%~50%.

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