A high-creep-resistant nickel-based powder superalloy and a method for preparing the same

Abstract

This invention discloses a nickel-based powder superalloy with high creep resistance and its preparation method, belonging to the field of high-temperature alloy technology, to solve the problem of low creep resistance of existing nickel-based powder superalloys at 815℃. The mass fractions of each element in the high-temperature alloy include: C 0.055%–0.065%, Co 14.0%–18.0%, Cr 9.0%–11.0%, Mo 2.3%–2.7%, W 4.0%–6.0%, Ta 4.0%–6.0%, Al 3.0%–3.4%, Ti 2.8%–3.2%, Nb 1.8%–2.1%, Hf 0.2%–0.4%, Zr 0.02%–0.04%, B 0.02%–0.04%, Mg 0.002%–0.010%, La 0.002%–0.012%, Ce 0.002%–0.012%, and the balance Ni. The high-creep-resistant nickel-based powder superalloy of this invention exhibits high creep resistance above 815°C.

Description

Technical Field

[0001] This invention belongs to the field of high-temperature alloy technology, specifically relating to a nickel-based powder high-temperature alloy with high creep resistance and its preparation method. Background Technology

[0002] Turbine disks are one of the most important hot-end components in an engine. During their service life, turbine disk alloys are required to have high tensile strength, excellent high-temperature creep resistance, fatigue performance, high damage tolerance, and excellent oxidation and corrosion resistance. Furthermore, turbine disk alloys are required to have a very low tendency for topologically packed (TCP) phase precipitation during long-term service, so that the alloy has good high-temperature structural stability and ensures that the degradation of the alloy's mechanical properties is minimized.

[0003] With the development of engines, the operating temperature of turbine disks is getting higher and higher. Currently, newly developed and researched engines require turbine disks to operate at a temperature of 815℃. However, existing nickel-based powder superalloys used for turbine disks, such as FGH4098 alloy, have a maximum service temperature limit of 750℃. Above 750℃, creep resistance decreases, and severe topologically dense (TCP) phases appear, which cannot meet the creep performance requirements at 815℃. Summary of the Invention

[0004] In view of the above analysis, the present invention aims to provide a nickel-based powder superalloy with high creep resistance and its preparation method, in order to solve the following technical problem: the existing nickel-based powder superalloys have low creep resistance at 815℃.

[0005] The objective of this invention is mainly achieved through the following technical solutions:

[0006] On one hand, the present invention provides a nickel-based powder superalloy with high creep resistance. The mass fraction of each element in the high creep resistance nickel-based powder superalloy includes: C 0.055%~0.065%, Co 14.0%~18.0%, Cr 9.0%~11.0%, Mo 2.3%~2.7%, W 4.0%~6.0%, Ta 4.0%~6.0%, Al 3.0%~3.4%, Ti 2.8%~3.2%, Nb 1.8%~2.1%, Hf 0.2%~0.4%, Zr 0.02%~0.04%, B 0.02%~0.04%, Mg 0.002%~0.010%, La 0.002%~0.012%, Ce 0.002%~0.012%, and the balance Ni.

[0007] Furthermore, the mass fraction ratio of (C+Ti) / (Ti+Nb+Ta+Hf) is 0.27 to 0.42.

[0008] Furthermore, the total mass fraction of Co, Cr, Mo, and W is 32.0% to 36.5%.

[0009] Furthermore, the total mass fraction of W and Ta is 9.0%–11.0%.

[0010] Furthermore, the mass fraction ratio of Ta to W, Ta / W, is 0.8 to 1.3.

[0011] Furthermore, the total mass fraction of Al, Ti, Nb, Ta, and Hf is 11.5% to 14.5%.

[0012] Furthermore, the total mass fraction of Al and Ti is 6.0% to 6.5%.

[0013] Furthermore, the microstructure of the high creep-resistant nickel-based powder superalloy includes a γ matrix phase and precipitates, with a uniform structure and dispersed precipitates. The precipitates mainly include the γ′ phase, MC-type carbides, and M3B2-type borides. The γ′ phase is of the (Ni,Co)3(Al,Ti,Ta,Nb,W,Hf) type, and the MC-type carbides are of the (Ti,Ta,Nb,Hf)C type. The element Ta is mainly distributed in the γ′ phase. The elements Mg, rare earth elements La, and Ce enter the γ matrix phase and agglomerate at the grain boundaries.

[0014] This invention also provides a method for preparing a nickel-based powder superalloy with high creep resistance, comprising the following steps:

[0015] Step 1: Prepare the alloy using vacuum induction melting process according to the mass fraction ratio, and obtain alloy bars;

[0016] Step 2: The alloy rod is powdered, sieved, and electrostatically treated using the plasma rotating electrode method to obtain alloy powder with a diameter of 50μm to 150μm.

[0017] Step 3: Under vacuum conditions, the alloy powder is loaded into a low-carbon steel sleeve, degassed and sealed, and then hot isostatically pressed to obtain an ingot.

[0018] Step 4: Heat treat the ingot, including solution treatment and aging treatment, to obtain a nickel-based powder superalloy with high creep resistance.

[0019] Furthermore, in step 4, the solution treatment process parameters are: 1190℃~1220℃ / 2h~6h / air cooling, and the aging treatment process parameters are: 790℃~820℃ / 4h~20h / air cooling.

[0020] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0021] a) The high creep resistance nickel-based powder superalloy of the present invention is strengthened by adding solid solution strengthening elements (Co, Cr, Mo, W), γ′ phase forming elements (Al, Ti, Nb, Ta, Hf) and grain boundary strengthening elements (B, Zr, Mg, La, Ce); by adding a high (W+Ta) content, especially by adding appropriate amounts of Mg, rare earth elements La and Ce, and coarse grains, the excellent high-temperature creep resistance of the alloy is achieved; and by controlling the total amount of Al, Ti, Nb and Ta elements, the γ′ phase content reaches 57% to 62% (mass fraction), giving full play to the γ′ phase strengthening, thereby obtaining a composition range with good comprehensive mechanical properties.

[0022] b) The high-temperature alloy of the present invention eliminates the precipitation of MC-type carbides at the original particle boundaries of the powder by controlling the (C+Ti) / (Ti+Nb+Ta+Hf) content ratio to be less than 0.5, i.e., eliminating the original particle boundary structure (PPBS), thereby avoiding the resulting degradation of mechanical properties; by coordinating and controlling the contents of Co, Cr, Mo, W, and Ta to reduce the tendency of TCP phase precipitation, the high-temperature microstructure stability of the alloy is improved; the microstructure of the high-temperature alloy of the present invention includes a γ matrix phase and precipitated phases, the microstructure is uniform, and the precipitated phases are diffusely distributed; the precipitated phases mainly include γ′ phase, MC-type carbides, and M3B2-type borides; the composition of the γ′ phase is (Ni,Co)3(Al,Ti,Ta,Nb,W,Hf) type, and the composition of the MC-type carbides is (Ti,Ta,Nb,Hf)C type; element Ta is mainly distributed in the γ′ phase; element Mg, rare earth element La, and Ce enter the γ matrix phase and agglomerate on the grain boundaries.

[0023] c) The nickel-based powder superalloy provided by the present invention has excellent comprehensive performance. The alloy has high creep resistance above 815°C, which enables the maximum operating temperature of the superalloy of the present invention to reach above 815°C, and it can be suitable for higher maximum operating temperatures.

[0024] d) In the preparation method of the present invention, air cooling can be used in the solution treatment and aging treatment steps to obtain nickel-based powder superalloy with high creep resistance. The process is simple and economical, environmentally friendly and widely applicable compared with commonly used cooling methods such as salt cooling or oil cooling.

[0025] 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 from the written description. Attached Figure Description

[0026] The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the invention.

[0027] Figure 1 The grain structure characterization results of the heat-treated state of GNPM01-19 nickel-based powder superalloy in the embodiments of the present invention are shown.

[0028] Figure 2 The results show the characterization of the relationship between LM parameter P and stress σ of GNPM01-19 nickel-based powder superalloy in this embodiment of the invention. Detailed Implementation

[0029] The preferred embodiments of the present invention are described in detail below. These embodiments are only used to illustrate the principles of the present invention and are not intended to limit the scope of the present invention.

[0030] This invention provides a nickel-based powder superalloy with high creep resistance. The mass fractions of each element in the high creep resistance nickel-based powder superalloy are as follows: C 0.055%–0.065%, Co 14.0%–18.0%, Cr 9.0%–11.0%, Mo 2.3%–2.7%, W 4.0%–6.0%, Ta 4.0%–6.0%, Al 3.0%–3.4%, Ti 2.8%–3.2%, Nb 1.8%–2.1%, Hf 0.2%–0.4%, Zr 0.02%–0.04%, B 0.02%–0.04%, Mg 0.002%–0.010%, La 0.002%–0.012%, Ce 0.002% to 0.012%, and the balance Ni; wherein the mass fraction ratio of (C+Ti) / (Ti+Nb+Ta+Hf) is 0.27 to 0.42, the total mass fraction of Co, Cr, Mo, and W is 32.0% to 36.5%, the total mass fraction of W and Ta is 9.0% to 11.0%, the mass fraction ratio of Ta to W (Ta / W) is 0.8 to 1.3, the total mass fraction of Al, Ti, Nb, Ta, and Hf is 11.5% to 14.5%, and the total mass fraction of Al and Ti is 6.0% to 6.5%.

[0031] Specifically, the microstructure of the high creep resistance nickel-based powder superalloy of the present invention includes a γ matrix phase and precipitated phases, with uniform microstructure and dispersed precipitated phases. The precipitated phases mainly include γ′ phase, MC-type carbides and M3B2-type borides. The γ′ phase is of the (Ni,Co)3(Al,Ti,Ta,Nb,W,Hf) type, and the MC-type carbides are of the (Ti,Ta,Nb,Hf)C type. Element Ta is mainly distributed in the γ′ phase. Element Mg, rare earth elements La and Ce enter the γ matrix phase and segregate at the grain boundaries.

[0032] Specifically, the content of the aforementioned γ′ phase is 57%–62% (mass fraction).

[0033] Specifically, 62% to 70% of Ta enters the γ′ phase.

[0034] Specifically, the complete dissolution temperature of the aforementioned γ′ phase is 1170℃~1200℃.

[0035] Specifically, considering that the effect of coarse grains on improving creep resistance cannot be ignored, the grain size of the above-mentioned high creep resistance nickel-based powder superalloy is 4.5 to 5.0 grade.

[0036] The elements in this invention will be described in detail below, and the content refers to the mass fraction of each element.

[0037] This invention strengthens the alloy by adding solid solution strengthening elements (Co, Cr, Mo, W), γ′ phase forming elements (Al, Ti, Nb, Ta, Hf), and grain boundary strengthening elements (B, Zr, Mg, La, Ce). By adding a high (W+Ta) content, especially by adding appropriate amounts of Mg, rare earth elements La and Ce, and combining with coarse grains, the alloy achieves excellent high-temperature creep resistance, thereby obtaining a composition range with good comprehensive mechanical properties.

[0038] In the high creep-resistant nickel-based powder superalloy of this invention, elements Mg, La, and Ce enter the γ matrix phase and segregate at the grain boundaries, strengthening them and thus improving creep resistance and endurance strength. Mg reacts with sulfur to form high-melting-point MgS, purifying the grain boundaries and reducing the harmful effects of sulfur. Appropriate amounts of Mg effectively disperse and refine coarse carbides at the grain boundaries; too low a Mg content has little effect, while too high a Mg content causes grain boundary carbides to aggregate, easily forming cracks during creep and causing adverse effects. Therefore, the Mg content is controlled at 0.002%–0.010% in this invention.

[0039] Rare earth elements La and Ce can remove O, S, and N, causing oxides, sulfides, and nitrides segregating along grain boundaries to disappear, reducing the harmful effects of O, S, and N, and thus purifying the grain boundaries. Secondly, La and Ce segregate at grain boundaries, affecting the segregation behavior of other elements at the grain boundaries, altering the precipitation of carbides. Appropriate amounts of La and Ce slow down the precipitation rate of carbides, delaying crack formation and hindering crack propagation. Thirdly, La and Ce increase the creep activation energy of the alloy and reduce the creep rate, thereby improving creep resistance and creep life. Excessive content of La and Ce can form undesirable phases with Ni, weakening the grain boundaries. Simultaneously adding appropriate amounts of Mg, La, and Ce can leverage their respective advantages to achieve a synergistic strengthening effect, better strengthening the grain boundaries. Therefore, in this invention, La is controlled at 0.002%–0.012%, and Ce at 0.002%–0.012%. Preferably, La is 0.003% to 0.01%, and Ce is 0.003% to 0.01%.

[0040] This invention eliminates the precipitation of MC-type carbides at the original particle boundaries of powder by controlling the (C+Ti) / (Ti+Nb+Ta+Hf) content ratio to be less than 0.5, i.e., eliminating the original particle boundary structure (PPBS), thereby avoiding the resulting degradation of mechanical properties; therefore, in this invention, the mass fraction ratio of (C+Ti) / (Ti+Nb+Ta+Hf) is controlled to be 0.27 to 0.42.

[0041] This invention reduces the tendency for TCP phase precipitation and improves the high-temperature microstructure stability of the alloy by coordinating and controlling the content of elements such as Co, Cr, Mo, W, and Ta, thereby enabling the alloy to have a higher maximum operating temperature. Therefore, the total mass fraction of Co, Cr, Mo, and W is controlled at 32.0% to 36.5% in this invention.

[0042] Due to factors such as crystal structure, atomic size, and self-diffusion coefficient, elements W and Ta can enter both the γ matrix and the γ′ phase, with most of Ta entering the γ′ phase. Therefore, they simultaneously strengthen both the γ matrix and the γ′ phase, with Ta having a more significant effect on strengthening the γ′ phase. W and Ta contribute to improving the high-temperature creep resistance of the alloy, especially Ta, which has a more pronounced effect on improving high-temperature creep resistance. Ta causes element W to have a reverse distribution effect, meaning that as the amount of Ta added increases, more W enters the γ matrix phase. The higher the total amount of W and Ta, the better the high-temperature creep resistance and endurance performance. Only when the total mass fraction of W and Ta is above 9.0% can excellent creep resistance and endurance performance at 815℃ be obtained. Therefore, in this invention, the total mass fraction of W and Ta is controlled at 9.0% to 11.0%, and the mass fraction ratio of Ta to W, Ta / W, is 0.8 to 1.3.

[0043] To further improve the creep resistance of nickel-based powder superalloys, the mass fraction of each element in the high creep resistance nickel-based powder superalloy of the present invention may include: C 0.058%–0.062%, Co 15.9%–16.2%, Cr 9.5%–10.5%, Mo 2.45%–2.6%, W 4.3%–5.5%, Ta 4.3%–5.7%, Al 3.1%–3.3%, Ti 2.9%–3.2%, Nb 1.95%–2.1%, Hf 0.25%–0.38%, Zr 0.025%–0.04%, B 0.02%–0.03%, Mg 0.004%–0.010%, La 0.003%–0.008%, Ce 0.003%–0.007%, and the balance Ni.

[0044] Preferably, the mass fraction ratio of (C+Ti) / (Ti+Nb+Ta+Hf) is controlled to be 0.28 to 0.35.

[0045] Preferably, the total mass fraction of Co, Cr, Mo, and W is controlled to be 32.0% to 34.5%.

[0046] Preferably, the total mass fraction of W and Ta is controlled to be 9.5% to 11.0%.

[0047] Preferably, the mass fraction ratio of Ta to W, Ta / W, is controlled to be 0.8 to 1.25.

[0048] Preferably, the total mass fraction of Al, Ti, Nb, Ta, and Hf is controlled to be 12.5% ​​to 14.2%.

[0049] Preferably, the total mass fraction of Al and Ti is controlled to be 6.1% to 6.45%.

[0050] This invention also provides a method for preparing a nickel-based powder superalloy with high creep resistance, comprising the following steps:

[0051] Step 1: Prepare the alloy using vacuum induction melting process according to the mass fraction ratio, and obtain alloy bars;

[0052] Step 2: The alloy rod is powdered, sieved, and electrostatically treated using the plasma rotating electrode method to obtain alloy powder with a diameter of 50μm to 150μm.

[0053] Step 3: Under vacuum conditions, the alloy powder is loaded into a low-carbon steel sleeve, degassed and sealed, and then hot isostatically pressed to obtain an ingot.

[0054] Step 4: Heat treat the ingot, including solution treatment and aging treatment, to obtain a nickel-based powder superalloy with high creep resistance.

[0055] Specifically, in step 2 above, the powder is cooled in a mixture of argon and helium gas during the powder preparation process. The cooling rate is extremely fast, resulting in micron-sized alloy powder with uniform alloy composition.

[0056] Specifically, in step 3 above, the process parameters for hot isostatic pressing are: temperature 1190℃~1210℃, pressure 120MPa~140MPa, and holding time 2h~6h.

[0057] Specifically, in step 4 above, the solution treatment process parameters are: 1190℃~1220℃ / 2h~6h / air cooling, and the aging treatment process parameters are: 790℃~820℃ / 4h~20h / air cooling.

[0058] In the preparation method of the present invention, the alloy composition is uniform because the micron-sized alloy powder of the high-temperature alloy is formed by cooling at a high cooling rate.

[0059] The high creep resistance nickel-based powder superalloy of the present invention has a uniform microstructure and dispersed precipitates, which eliminates macrosegregation and can further improve the degree of alloying, so that the alloy has good high-temperature tensile strength, yield strength and high-temperature creep resistance.

[0060] Specifically, the mechanical properties of the aforementioned high creep resistance nickel-based powder superalloys are as follows:

[0061] Room temperature mechanical properties: tensile strength of ≥1590MPa (e.g., 1595~1620MPa), yield strength of ≥1260MPa (e.g., 1260~1275MPa), elongation after fracture of ≥10.0% (e.g., 10.2%~11%), and reduction of area of ​​≥11% (e.g., 11.5%~13%).

[0062] Mechanical properties at 815℃: tensile strength of 1170MPa or higher (e.g., 1175-1185MPa), yield strength of 1040MPa or higher (e.g., 1045-1060MPa), elongation after fracture of 5.5% or higher (e.g., 5.8%-6.0%), and reduction of area of ​​7.5% or higher (e.g., 7.8%-8.5%).

[0063] Creep resistance at 815℃: Test conditions 815℃ / 450MPa: Creep life greater than 890h, for example 895~920h; Test conditions 815℃ / 400MPa: Plastic strain less than 0.1% after 50h, for example 0.08%~0.1%.

[0064] In the preparation method of the present invention, air cooling is used in the solution treatment and aging treatment steps to obtain nickel-based powder superalloys with high creep resistance. The process is simple and economical, environmentally friendly and widely applicable compared with commonly used cooling methods such as salt cooling or oil cooling.

[0065] The high creep resistance nickel-based powder superalloy of the present invention can reach a maximum operating temperature of over 815°C, which can meet the stringent requirements of engines for material performance at high temperatures and can be used as a high-temperature material in temperature scenarios above 815°C.

[0066] The advantages of precise control of composition and process parameters of the high creep resistance nickel-based powder superalloy of the present invention will be demonstrated below with specific embodiments and comparative examples.

[0067] Example

[0068] This embodiment provides a nickel-based powder superalloy with high creep resistance. The composition and processing conditions of this high creep-resistant nickel-based powder superalloy are shown in Table 1 below. GNPM01-19, GNPM01-19-1, and GNPM01-19-2 are embodiments of this invention. GNPM01-17, 1 # and 2 # These are samples that performed relatively poorly during the inventor's research process, and are used as comparative examples for this invention.

[0069] The specific preparation method of nickel-based powder superalloys with high creep resistance is as follows:

[0070] (1) Prepare raw materials according to the chemical composition and mass fraction of the high-temperature alloy, and prepare alloy bars using a 25kg vacuum induction melting process;

[0071] (2) The alloy rods were used to prepare high-temperature alloy powder by plasma rotating electrode method. The alloy powder was sieved and electrostatically treated to obtain alloy powder with a particle size of 50μm to 150μm.

[0072] (3) Under vacuum conditions, the alloy powder is loaded into a low-carbon steel sheath, degassed and sealed.

[0073] (4) The sealed sleeve is subjected to hot isostatic pressing to obtain an ingot;

[0074] (5) Heat treatment is performed on the formed ingot to obtain powder high-temperature alloy parts; heat treatment includes solution treatment and aging treatment.

[0075] Table 1. Composition and preparation process parameters of nickel-based powder superalloy samples

[0076]

[0077]

[0078]

[0079] The microstructure of the above alloys in the heat-treated state and after long-term aging was observed using a metallographic microscope to characterize the prepared GNPM01-17, GNPM01-19, GNPM01-19-1, GNPM01-19-2, and 1 # and 2 # Microstructure of nickel-based powder superalloys.

[0080] Taking GNPM01-19 nickel-based powder superalloy as a typical example, its grain structure in the heat-treated state is as follows: Figure 1 As shown.

[0081] The microstructure of the nickel-based powder superalloy provided by the present invention mainly consists of a matrix γ phase, γ′ phase, MC-type carbides and M3B2-type borides. The γ′ phase is of the (Ni,Co)3(Al,Ti,Ta,Nb,W,Hf) type, and the MC-type carbides are of the (Ti,Ta,Nb,Hf)C type.

[0082] GNPM01-17, GNPM01-19, GNPM01-19-1, GNPM01-19-2, 1 # and 2 # The nickel-based powder superalloy has a γ′ phase content of 58%–60% (mass fraction), a complete dissolution temperature of γ′ phase of 1180℃–1200℃, and a grain size of 4.5–5.0. Coarse grains are beneficial for improving creep resistance and service life.

[0083] Microstructural observation showed that no TCP phase precipitate was observed in the nickel-based powder superalloy after aging heat treatment at 815℃ for 3000h, indicating that it has excellent high-temperature structural stability at 815℃.

[0084] GNPM01-17, GNPM01-19, GNPM01-19-1, GNPM01-19-2, 1 # and 2 # The room temperature and 815℃ mechanical properties and 815℃ creep resistance of nickel-based powder superalloys are listed in Tables 2, 3, and 4, respectively. The relationship between the LMP parameter P and stress σ is as follows: Figure 2 As shown.

[0085] Table 2 Room temperature mechanical properties of nickel-based powder superalloys

[0086] Alloy Number <![CDATA[R m / MPa]]> <![CDATA[R p0.2 / MPa]]> A / ％ Z / ％ GNPM01-17 1612 1267 9.5 10.5 GNPM01-19 1610 1265 10.5 12.0 GNPM01-19-1 1608 1263 10.6 12.2 GNPM01-19-2 1610 1266 10.4 11.8 <![CDATA[1 # ]]> 1595 1244 13.2 14.6 <![CDATA[2 # ]]> 1585 1240 12.8 13.4 FGH4098 1587 1152 18.0 21.0

[0087] Table 3 Mechanical properties of nickel-based powder superalloys at 815℃

[0088]

[0089]

[0090] Table 4. Creep resistance of nickel-based powder superalloys at 815℃

[0091]

[0092] From the data in Table 4 and Figure 2It can be seen that, compared with the existing FGH4098 alloy, the minimum creep rate of the alloy of the present invention at 815℃ is significantly reduced, while the creep rupture life and creep strength are also significantly improved; in particular, the addition of small amounts of Mg, Ce, and La reduces the minimum creep rate of the alloy and improves the creep rupture life (compared to GNPM01-17 alloy); at the same time, the addition of W and Ta increases the total amount from 8.0% to about 10.0%, improving the creep resistance (compared to GNPM01-17 alloy). # and 2 # (Compared to other alloys). The alloy of this invention has a creep strength greater than 520 MPa at 815℃ / 100h, while the GNPM01-19 alloy reaches 590 MPa. It is evident that the nickel-based powder superalloy provided by this invention possesses excellent high-temperature creep resistance.

[0093] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A high-creep-resistant, nickel-base powder metallurgy superalloy characterized in that, The mass fraction of each element of the high-creep-resistance nickel-based powder superalloy comprises: C 0.055%~0.065%, Co 14.0%~18.0%, Cr 9.0%~11.0%, Mo 2.3%~2.7%, W 4.0%~6.0%, Ta 4.0%~6.0%, Al 3.0%~3.4%, Ti 2.8%~3.2%, Nb 1.8%~2.1%, Hf 0.2%~0.4%, Zr 0.02%~0.04%, B 0.02%~0.04%, Mg 0.002%~0.010%, La 0.002%~0.012%, Ce 0.002%~0.012%, and the balance of Ni; The mechanical properties of the high-creep-resistance nickel-based powder superalloy at 815℃ are: the tensile strength reaches 1170MPa or above, the yield strength is 1040MPa or above, the elongation after fracture is 5.5% or above, and the reduction of area is 7.5% or above.

2. The high-creep-resistant, nickel-base powder metallurgy superalloy of claim 1, wherein, The mass fraction ratio of (C+Ti) / (Ti+Nb+Ta+Hf) is 0.27~0.

35.

3. The high-creep-resistant, nickel-base powder metallurgy superalloy of claim 1, wherein, The total mass fraction of Co, Cr, Mo and W is 32.0%~36.5%.

4. The high-creep-resistant, nickel-base powder metallurgy superalloy of claim 1, wherein, The total mass fraction of W and Ta is 9.0%~11.0%.

5. The high-creep-resistant, nickel-base powder metallurgy superalloy of claim 1, wherein, The mass fraction ratio of Ta / W is 0.8~1.

3.

6. The high-creep-resistant, nickel-base powder metallurgy superalloy of claim 1, wherein, The total mass fraction of Al, Ti, Nb, Ta and Hf is 12.5%~14.5%.

7. The high-creep-resistant, nickel-base powder metallurgy superalloy of claim 1, wherein, The total mass fraction of Al and Ti is 6.0%~6.5%.

8. The high-creep-resistant nickel-base powder metallurgy superalloy of any of claims 1-7, wherein, The microstructure of the high-creep-resistance nickel-based powder superalloy comprises a γ matrix phase and precipitates, the structure is uniform, and the precipitates are dispersedly distributed; the precipitates mainly comprise γ' phase, MC type carbide and M3B2 type boride; the composition of the γ' phase is (Ni, Co)3(Al, Ti, Ta, Nb, W, Hf) type, and the composition of the MC type carbide is (Ti, Ta, Nb, Hf)C type; element Ta is mainly distributed in the γ' phase; elements Mg, rare earth elements La and Ce enter the γ matrix phase and segregate on the grain boundary.

9. A method of producing a high-creep-resistant nickel-based powder superalloy, characterized by, A method for manufacturing the high-creep-resistance nickel-based powder superalloy of any one of claims 1-8 comprises the following steps: Step 1, preparing an alloy by vacuum induction melting process according to the mass fraction ratio, and obtaining an alloy bar; Step 2, powdering the alloy bar by plasma rotating electrode method, screening, and electrostatic treatment to obtain an alloy powder of 50μm~150μm; Step 3, under vacuum condition, loading the alloy powder into a low-carbon steel jacket, degassing and sealing, and then performing hot isostatic pressing to obtain an ingot; Step 4, performing heat treatment on the ingot, which comprises solid solution treatment and aging treatment, to obtain the high-creep-resistance nickel-based powder superalloy.

10. The method of claim 9, wherein, In the step 4, the solid solution treatment process parameters are: 1190℃~1220℃ / 2h~6h / air cooling, and the aging treatment process parameters are: 790℃~820℃ / 4h~20h / air cooling.

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