A creep-resistant and oxidation-resistant nickel-based high-temperature alloy and its preparation method and application

Abstract

The present invention discloses a creep-resistant and oxidation-resistant nickel-based superalloy, comprising: C: 0.07 to 0.2%; Cr: 7.0 to 9.0%; Co: 9.0 to 11.0%; W: 8.5 to 10.6%; Mo: 0.1 to 1.5%; Ta: 2.5 to 4.0%; Al: 4.2 to 6.5%; Ti: 0.4 to 2.5%; B: 0.012 to 0.025%; Hf: 1.2 to 2.5%; Zr: 0.003 to 0.008%; Mg ≤ 0.005%; Si ≤ 0.15%; Mn ≤ 0.05%; Sr: 0.03 to 0.08%; the balance being Ni and unavoidable impurities, by mass percentage, wherein, Cr, C and Sr satisfy the relationship 5.5 < Cr - C / Sr < 7.5. The nickel-based alloy of the present invention has excellent properties and can be applied to aeroengines and gas turbines.

Description

Technical Field

[0001] The present invention belongs to the technical field of nickel-based high-temperature alloys, and in particular relates to a creep-resistant and oxidation-resistant nickel-based high-temperature alloy and a preparation method and application thereof. Background Art

[0002] High-temperature alloy materials generally refer to materials that work under certain stress load conditions above 600°C. They need to have good strength-toughness matching and oxidation resistance, as well as excellent high-temperature strength and creep resistance, fatigue resistance and other properties.

[0003] Since nickel-based alloys have the best performance among similar high-temperature alloys, especially their performance under high temperature conditions is much higher than other alloys, they have the widest application range. The main chemical properties of nickel-based alloys are as follows: First, a variety of alloying elements can be dissolved in nickel-based alloys, which greatly helps to improve their performance; second, nickel-based alloys have strong organizational stability and good application effects in special environments; third, nickel-based alloys have strong anti-oxidation and anti-corrosion capabilities.

[0004] At present, the working conditions of the hot end parts of advanced aircraft engines and gas turbines can reach up to 1300℃, and the stress is complex, which places stringent requirements on alloy materials. Alloys that can meet the tensile strength requirements cannot meet the creep resistance requirements. There are almost no alloys that can fully meet the tensile strength and creep resistance requirements and have good oxidation resistance among the existing high-temperature alloys at home and abroad.

[0005] Therefore, how to produce high-temperature alloys that meet the needs of aircraft engines and gas turbines has received more and more attention. Summary of the invention

[0006] The present invention is based on the inventor's discovery and understanding of the following facts and problems:

[0007] Key hot-end components of modern gas turbine engines require nickel-based high-temperature alloys to have long-term high-temperature structural stability, fatigue resistance, corrosion resistance, and oxidation resistance. However, during long-term service at high temperatures, nickel-based high-temperature alloys will experience a significant decline in mechanical properties such as fatigue strength, yield strength, and ultimate tensile strength. With the continuous development of the aerospace industry, the performance requirements of aircraft engines are getting higher and higher, and the high-temperature materials used require higher temperature bearing capacity, better creep resistance, and oxidation resistance.

[0008] The present invention aims to solve at least one of the technical problems in the related art to some extent. To this end, an embodiment of the present invention provides a creep-resistant and oxidation-resistant nickel-based superalloy, which not only has high tensile strength, but also excellent plasticity, good creep life and oxidation resistance, fully meeting the requirements for the design and use of advanced aero-engines and gas turbines, and is applicable to components such as turbine blades in the hot end parts of aero-engines and gas turbines for medium- and long-term service.

[0009] The creep-resistant and oxidation-resistant nickel-based superalloy according to the embodiment of the present invention comprises: C: 0.07-0.2%; Cr: 7.0-9.0%; Co: 9.0-11.0%; W: 8.5-10.6%; Mo: 0.1-1.5%; Ta: 2.5-4.0%; Al: 4.2-6.5%; Ti: 0.4-2.5%; B: 0.012-0.025%; Hf: 1.2-2.5%; Zr: 0.003-0.008%; Mg≤0.005%; Si≤0.15%; Mn≤0.05%; Sr: 0.03-0.08%; the balance being Ni and unavoidable impurities, by mass percentage.

[0010] Wherein, the Cr, C and Sr satisfy the relation 5.5 < Cr - C / Sr < 7.5, and in the relation, Cr, C and Sr are the values after removing the percentage sign of the mass percentages of the elements Cr, C and Sr in the nickel-based superalloy.

[0011] The advantages and technical effects brought by the creep-resistant and oxidation-resistant nickel-based superalloy according to the embodiment of the present invention are as follows: 1. In the embodiment of the present invention, the element Sr is added to the alloy. Sr can significantly refine the alloy grains and improve the oxidation resistance of the alloy at the same time; 2. In the embodiment of the present invention, by controlling the amounts of various metal elements within a reasonable range and controlling the ratio among Cr, C and Sr to satisfy 5.5 < Cr - C / Sr < 7.5, the tensile properties and creep life of the alloy are effectively improved, and it has good oxidation resistance, with excellent comprehensive properties, and can be applied to advanced aero-engines and gas turbines.

[0012] In some embodiments, the Cr, C and Sr satisfy the relation 5.7 ≤ Cr - C / Sr ≤ 7.1.

[0013] In some embodiments, the Hf, Ta and C satisfy the relation 0.18 < Hf / Ta - 2.25C < 0.56, wherein, Hf, Ta and C are the values after removing the percentage sign of the mass percentages of the elements Hf, Ta and C in the nickel-based superalloy.

[0014] In some embodiments, the Hf, Ta and C satisfy the relation 0.19 ≤ Hf / Ta - 2.25C ≤ 0.47.

[0015] In some examples, Sr and Mg satisfy the relationship 0.05 < Sr + 12.5Mg < 0.12, where Sr and Mg are the values obtained by removing the percentage sign from the mass percentage contents of elements Sr and Mg in the nickel-based superalloy.

[0016] In some embodiments, Sr and Mg satisfy the relationship 0.06 ≤ Sr + 12.5Mg ≤ 0.12.

[0017] In some embodiments, the nickel-based superalloy includes: C: 0.08 - 0.16%; Cr: 7.3 - 8.9%; Co: 9.2 - 10.9%; W: 8.9 - 10.5%; Mo: 0.2 - 1.5%; Ta: 2.8 - 4.0%; Al: 4.3 - 6.2%; Ti: 0.4 - 2.5%; B: 0.012 - 0.025%; Hf: 1.4 - 2.4%; Zr: 0.003 - 0.008%; Mg ≤ 0.004%; Si ≤ 0.03%; Mn ≤ 0.04%; Sr: 0.04 - 0.08%; the balance is Ni and unavoidable impurities, by mass percentage.

[0018] The embodiments of the present invention also provide an application of a creep-resistant and oxidation-resistant nickel-based superalloy in an aeroengine.

[0019] The embodiments of the present invention also provide an application of a creep-resistant and oxidation-resistant nickel-based superalloy in a gas turbine.

[0020] The embodiments of the present invention also provide a preparation method of a creep-resistant and oxidation-resistant nickel-based superalloy, including the following steps:

[0021] (1) According to the alloy design ratio, add Cr, Co, W, Mo, Ta, B, Hf, Zr, Mg, Si, Mn, Sr and part of the C raw materials into the crucible, heat and melt them under vacuum, and then carry out heat preservation treatment;

[0022] (2) After the heat preservation treatment in step (1) is completed, add Al, Ti and the remaining C raw materials into the crucible, introduce argon, heat and melt them under vacuum, and cast to obtain the nickel-based superalloy.

[0023] The advantages and technical effects brought by the preparation method of the creep-resistant and oxidation-resistant nickel-based superalloy in the embodiments of the present invention are as follows: 1. In the method of the embodiments of the present invention, the easily burned C element is added step by step, which is beneficial to removing the gas in the alloy and improving the mechanical properties of the alloy; 2. In the method of the embodiments of the present invention, the obtained nickel-based superalloy not only has excellent tensile properties and creep rupture life, but also has excellent long-term service stability and oxidation resistance, and can meet the requirements of the design and use of advanced aeroengines and gas turbines. Specific Embodiments

[0024] The embodiments of the present invention will be described in detail below. The embodiments are exemplary and are intended to explain the present invention, but should not be construed as limiting the present invention.

[0025] The creep-resistant and oxidation-resistant nickel-based superalloy of the embodiments of the present invention includes: C: 0.07 - 0.2%; Cr: 7.0 - 9.0%; Co: 9.0 - 11.0%; W: 8.5 - 10.6%; Mo: 0.1 - 1.5%; Ta: 2.5 - 4.0%; Al: 4.2 - 6.5%; Ti: 0.4 - 2.5%; B: 0.012 - 0.025%; Hf: 1.2 - 2.5%; Zr: 0.003 - 0.008%; Mg ≤ 0.005%; Si ≤ 0.15%; Mn ≤ 0.05%; Sr: 0.03 - 0.08%; the balance is Ni and unavoidable impurities, by mass percentage;

[0026] Among them, the Cr, C, and Sr satisfy the relationship 5.5 < Cr - C / Sr < 7.5, preferably 5.7 ≤ Cr - C / Sr ≤ 7.1. In the relationship, Cr, C, and Sr are the values after removing the percentage signs of the mass percentages of the elements Cr, C, and Sr in the nickel-based superalloy.

[0027] The creep-resistant and oxidation-resistant nickel-based superalloy of the embodiments of the present invention adds the element Sr to the alloy. Sr can significantly refine the alloy grains and improve the oxidation resistance of the alloy at the same time. By controlling the dosages of various metal elements within a reasonable range and controlling the ratio among Cr, C, and Sr to satisfy 5.5 < Cr - C / Sr < 7.5, the tensile properties and creep rupture life of the alloy are effectively improved, and it has good oxidation resistance, with excellent comprehensive properties, and can be applied to advanced aeroengines and gas turbines.

[0028] Among them, the functions of the main elements in the alloy of the embodiments of the present invention are as follows:

[0029] C: The MC-type carbides formed by C in the nickel-based superalloy inhibit the growth of austenite grains during heating and form carbides such as M 23 C6 along the grain boundaries during heat treatment, playing a role in strengthening the grain boundaries, which can delay the initiation, propagation, and coalescence of microcracks, thereby improving the high-temperature creep rupture life of the alloy. In the embodiments of the present invention, the content of the element C is controlled within 0.07 - 0.2%.

[0030] Cr: Cr can improve the oxidation resistance of the alloy and has a certain solid-solution strengthening effect, playing a role in strengthening the grain boundaries. In the embodiments of the present invention, the content of the element Cr is controlled within 7.0 - 9.0%.

[0031] Co: Co is an important solid solution strengthening element and precipitation strengthening element. The Co element can improve the creep resistance and endurance of the alloy and improve the stability of the phase in long-term service. Co can also reduce the solubility of Al and Ti elements in the matrix, promote the precipitation of γ′ strengthening phase and increase its precipitation amount and solid solution temperature. In the embodiment of the present invention, the Co content is controlled at 9.0-11.0%.

[0032] W and Mo: W and Mo are solid solution strengthening elements, which can be dissolved in the alloy matrix and the γ′ strengthening phase, and can improve the interatomic bonding force, increase the diffusion activation energy and recrystallization temperature, thereby effectively improving the high temperature strength; W is easy to form carbides in the alloy, which can cooperate with γ′ to strengthen and improve the strength of the alloy. In the embodiment of the present invention, the Mo content is controlled at 0.1-1.5%, and the W content is controlled at 8.5-10.6%.

[0033] Al, Ti and Ta: are the elements that form the strengthening phase γ' in nickel-based alloys. As the content of the three increases, the amount of γ' increases, and the high-temperature creep and endurance properties are improved; in addition, Ti and Ta will also combine with C to form MC-type carbides, which hinder grain boundary growth and grain boundary sliding at high temperatures, and play a role in improving high-temperature mechanical properties. In the embodiment of the present invention, the content of the three is controlled to: Al: 4.2-6.5%, Ti: 0.4-2.5%, Ta: 2.5-4.0%.

[0034] B: B atoms are easily enriched at the grain boundaries, so that harmful low-melting-point elements cannot be segregated at the grain boundaries, thereby improving the grain boundary bonding strength; borides on the grain boundaries can prevent grain boundary sliding, void initiation and expansion, which is beneficial to improving the creep resistance and long-lasting life of the alloy. In the embodiment of the present invention, the content of B is controlled to be 0.012-0.025%.

[0035] Zr: Zr helps to purify the grain boundary and enhance the grain boundary bonding force. The composite addition of Zr and B helps to maintain the high temperature strength and long life of the alloy. In the embodiment of the present invention, the content of Zr is controlled at 0.003-0.008%.

[0036] Mg: Mg is concentrated at the grain boundary to improve the grain boundary bonding force and grain boundary strength, and is also concentrated at the carbide phase boundary and γ′ phase boundary. Mg atoms also enter γ′ and carbide, which is beneficial to improve mechanical properties. In the embodiment of the present invention, the Mg content is controlled to be less than 0.005%.

[0037] Sr: The element Sr can significantly refine the grains, and the grain size of the alloy decreases with the increase of the Sr content. At the same time, Sr can improve the oxidation resistance of the alloy, and the increase of the Sr content is beneficial to improving the oxidation resistance of the alloy. However, with the addition of Sr, a compound phase distributed in a network along the grain boundaries will appear in the alloy, increasing the brittleness of the as-cast alloy; with the increase of the Sr content, the strength and elongation of the as-cast alloy show a downward trend. Therefore, in the embodiments of the present invention, the Sr content is controlled within 0.03 - 0.08%.

[0038] In some embodiments, preferably, Hf, Ta, and C satisfy the relationship 0.18 < Hf / Ta - 2.25C < 0.56, where Hf, Ta, and C are the values obtained by removing the percentage sign from the mass percentage contents of the elements Hf, Ta, and C in the nickel-based superalloy. Further preferably, Hf, Ta, and C satisfy the relationship 0.19 ≤ Hf / Ta - 2.25C ≤ 0.47.

[0039] In the embodiments of the present invention, by controlling Hf, Ta, and C to satisfy the relationship 0.18 < Hf / Ta - 2.25C < 0.56, the proportional relationship of the elements Hf, Ta, and C that are prone to form carbides is adjusted to form a carbide phase beneficial to the strength of the alloy. Compared with the traditional Ni3(Al, Ti) strengthening phase, the superalloy in the embodiments of the present invention has more excellent high-temperature resistance.

[0040] In some embodiments, preferably, Sr and Mg satisfy the relationship 0.05 < Sr + 12.5Mg < 0.12, where Sr and Mg are the values obtained by removing the percentage sign from the mass percentage contents of the elements Sr and Mg in the nickel-based superalloy. Further preferably, Sr and Mg satisfy the relationship 0.06 ≤ Sr + 12.5Mg ≤ 0.12.

[0041] In the embodiments of the present invention, with the addition of Sr, a compound phase distributed in a network along the grain boundaries appears in the alloy, and excessive addition of Sr will lead to a decrease in the creep life of the alloy. In order to reduce the adverse effects of introducing Sr, the proportional relationship between Sr and Mg is further controlled in the embodiments of the present invention, which is beneficial to improving the oxidation resistance and creep life of the nickel-based alloy.

[0042] In some embodiments, preferably, the nickel-based high-temperature alloy includes: C: 0.08-0.16%; Cr: 7.3-8.9%; Co: 9.2-10.9%; W: 8.9-10.5%; Mo: 0.2-1.5%; Ta: 2.8-4.0%; Al: 4.3-62%; Ti: 0.4-2.5%; B: 0.012-0.025%; Hf: 1.4-2.4%; Zr: 0.003-0.008%; Mg≤0.004%; Si≤0.03%; Mn≤0.04%; Sr: 0.04-0.08%; the remainder is Ni and unavoidable impurities, calculated in percentage by mass.

[0043] The embodiment of the present invention also provides an application of a creep-resistant and oxidation-resistant nickel-based high-temperature alloy in the hot end components of an aircraft engine. The creep-resistant and oxidation-resistant nickel-based high-temperature alloy of the embodiment of the present invention has excellent creep resistance and oxidation resistance and can be applied to turbine blades, the hot end components of an aircraft engine.

[0044] The embodiment of the present invention also provides an application of a creep-resistant and oxidation-resistant nickel-based high-temperature alloy in a hot end component of a gas turbine. The creep-resistant and oxidation-resistant nickel-based high-temperature alloy of the embodiment of the present invention has excellent creep resistance and oxidation resistance and can be applied to turbine blades, which are hot end components of a gas turbine.

[0045] The embodiment of the present invention also provides a method for preparing a creep-resistant and oxidation-resistant nickel-based high-temperature alloy, comprising the following steps:

[0046] (1) According to the alloy design ratio, Cr, Co, W, Mo, Ta, B, Hf, Zr, Mg, Si, Mn, Sr and part of C raw materials are added into a crucible, heated and melted in vacuum, and then heat-insulated;

[0047] (2) After the heat preservation treatment in step (1) is completed, Al, Ti and the remaining C raw materials are added into the crucible, argon gas is introduced, and the crucible is heated and melted in a vacuum, and a nickel-based high-temperature alloy is cast.

[0048] The method for preparing the creep-resistant and oxidation-resistant nickel-based high-temperature alloy in the embodiment of the present invention adds the easily burnt C element step by step, which is beneficial to remove the gas in the alloy and improve the mechanical properties of the alloy; the prepared nickel-based high-temperature alloy not only has excellent tensile properties and long-lasting life, but also has excellent long-term service stability and oxidation resistance, and can meet the requirements of the design and use of advanced aircraft engines and gas turbines.

[0049] In some embodiments, preferably, in step (1), the portion of C raw material is 8-25% of the designed amount of C raw material, the insulation temperature is 1600°C-1650°C, and the insulation time is 10-30 minutes. In step (2), the amount of argon gas introduced is such that the pressure in the crucible is -0.02-0.1MPa; the vacuum degree of the vacuum condition is <0.1Pa, and the casting temperature is ≥1560°C.

[0050] The technical solution of the present invention is described in detail below in conjunction with specific embodiments.

[0051] Example 1

[0052] (1) Add Cr, Co, W, Mo, Ta, B, Hf, Zr, Mg, Si, Mn, Sr and 15% C raw materials into a crucible, heat in vacuum until completely melted, then control the temperature at 1610°C, the vacuum degree at less than 0.1 Pa, keep warm for 10 minutes, then stop heating and keep for 5 minutes;

[0053] (2) Add Al, Ti and the remaining C raw materials into the crucible; fill the furnace with argon gas to a pressure of -0.02 MPa, heat and melt under a vacuum degree of less than 0.1 Pa, cast the steel at 1560°C, cool to room temperature, demold, and perform surface sandblasting and grinding to remove oxide scale, thereby obtaining a nickel-based high-temperature alloy.

[0054] The preparation methods of Examples 2 to 8 are the same as that of Example 1, the only difference being the alloy composition.

[0055] The alloy compositions of Examples 1 to 8 are shown in Table 1, and the properties are shown in Table 2.

[0056] Comparative Example 1

[0057] The same as Example 1, except that the alloy does not contain Sr element.

[0058] The performance data of the alloy prepared in Comparative Example 1 are shown in Table 2.

[0059] Comparative Example 2

[0060] The same as Example 1, except that the Sr content of the alloy is 0.12%.

[0061] The performance data of the alloy prepared in Comparative Example 2 are shown in Table 2.

[0062] Comparative Example 3

[0063] The same as Example 1, except that the C content of the alloy is 0.08%, the Cr content is 8.9%, the Sr content is 0.08%, and the calculated Cr-C / Sr is 7.9%.

[0064] The performance data of the alloy prepared in Comparative Example 3 are shown in Table 2.

[0065] Comparative Example 4

[0066] It is the same as Example 1, except that the C content is 0.13%, the Cr content is 7.3%, the Sr content is 0.06%, and after calculation, Cr-C / Sr is 5.1%.

[0067] The performance data of the alloy prepared in Comparative Example 4 are shown in Table 2.

[0068] Comparative Example 5

[0069] It is the same as Example 1, except that the Ta content is 1.5% and the Hf content is 1.0%

[0070] The performance data of the alloy prepared in Comparative Example 5 are shown in Table 2.

[0071] Table 1

[0072] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 C(％) 0.1 0.12 0.12 0.15 0.09 0.13 0.12 0.16 Cr(％) 8.8 8.5 8.6 8.9 7.5 7.9 8.7 8.6 Co(%) 9.2 9.5 9.8 9.6 10.2 9.7 10.1 10.9 W(％) 9.5 10.2 9.7 10.1 10.3 9.8 10.2 10.5 Mo(%) 0.2 1 1.4 1.3 0.2 0.6 0.9 1.5 Ta(%) 3.8 3 3.5 3.2 2.9 2.8 3.1 4 Al(％) 5 4.5 4.3 4.6 4.7 5 5.8 6.2 Ti(%) 0.6 1 1.3 1.2 1.5 0.5 0.4 2.5 B(％) 0.015 0.012 0.016 0.013 0.014 0.017 0.02 0.025 Hf(%) 1.5 1.4 2.1 2 1.6 2.1 1.9 2.4 Zr(％) 0.005 0.006 0.004 0.003 0.008 0.006 0.005 0.007 Mg(%) 0.002 0.002 0.004 0.001 0.001 0.003 0.004 0.001 Si(%) 0.01 0.02 0.01 0.01 0.01 0.02 0.01 0.03 Mn(%) 0.02 0.01 0.02 0.03 0.02 0.03 0.04 0.03 Sr(％) 0.04 0.05 0.08 0.08 0.07 0.06 0.07 0.06 Hf / Ta-2.25C 0.17 0.20 0.33 0.29 0.35 0.46 0.34 0.24 Cr-C / Sr 6.30 6.10 7.10 7.03 6.21 5.73 6.99 5.93 Sr+12.5Mg 0.065 0.075 0.130 0.093 0.083 0.098 0.120 0.073

[0073] Table 2

[0074]

[0075]

[0076] Note: 1. Rm is the tensile strength, Rp0.2 is the tensile yield strength, and A is the elongation.

[0077] 2. The average oxidation rate is the oxidation rate per unit area of the alloy at 900 °C / 100 h. The smaller this value, the better the oxidation resistance.

[0078] It can be seen from the data in the above table that the nickel-based superalloys prepared in Examples 1 to 8 have very good tensile properties at room temperature and 900 °C. At room temperature, the tensile properties are Rm ≥ 1200 MPa, Rp0.2 ≥ 890 MPa, A ≥ 8%; at 900 °C, the tensile properties are Rm ≥ 870 MPa, Rp0.2 ≥ 590 MPa, A ≥ 8%. In addition, the nickel-based superalloys of the examples of the present invention also have excellent creep life and oxidation resistance. The creep time at 980 °C and 200 MPa is greater than 100 h, and the average oxidation rate is lower than 0.1 g / m 2 ·h. In particular, when the relational expressions 0.18 < Hf / Ta - 2.25C < 0.56 and 0.05 < Sr + 12.5Mg < 0.12 are further satisfied, as in Examples 2 and 4 to 8, the prepared nickel-based superalloys have more excellent properties.

[0079] Comparative Example 1 does not contain element Sr. Although the tensile strength and elongation at room temperature can be maintained at a relatively high level, the tensile properties at a high temperature of 900°C are greatly reduced. At the same time, the endurance time at 980°C and 200MPa is reduced to 65h, and the antioxidant performance is also significantly reduced. Comparative Example 2 has an excessively high content of element Sr. Although the tensile strength at room temperature and a high temperature of 900°C can be maintained at a high level, the elongation is significantly reduced, and the endurance time at 980°C and 200MPa is reduced to 59h. At the same time, the antioxidant performance is also reduced, which cannot meet the requirements of use.

[0080] In Comparative Examples 3 and 4, the controlled ratios of the three elements Cr, C, and Sr are not within the range to be controlled in the embodiments of the present invention, resulting in a serious decrease in the room temperature and high temperature tensile properties of the nickel-based alloy, and a significant decrease in the high temperature endurance life and oxidation resistance.

[0081] In Comparative Example 5, the content of element Ta is 1.5%, and the content of element Hf is 1.0%. Although the reduced contents of element Ta and Hf can make the alloy have good oxidation resistance, the tensile strength at room temperature and at a high temperature of 900°C is greatly reduced, and the endurance time at 980°C and 200MPa is only 39h, which cannot meet the requirements of use.

[0082] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0083] Although the above embodiments have been shown and described, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those of ordinary skill in the art are all within the scope of protection of the present invention.

Claims

1. A creep-resistant and oxidation-resistant nickel-based high-temperature alloy, characterized in that: Comprising: C: 0.07 - 0.2%; Cr: 7.0 - 9.0%; Co: 9.0 - 11.0%; W: 8.5 - 10.6%; Mo: 0.1 - 1.5%; Ta: 2.5 - 4.0%; Al: 4.2 - 6.5%; Ti: 0.4 - 2.5%; B: 0.012 - 0.025%; Hf: 1.2 - 2.5%; Zr: 0.003 - 0.008%; Mg ≤ 0.005%; Si ≤ 0.15%; Mn ≤ 0.05%; Sr: 0.03 - 0.08%; the balance being Ni and unavoidable impurities, by mass percentage; Wherein, the Cr, C and Sr satisfy the relationship 5.5 < Cr - C / Sr < 7.5, where Cr, C and Sr in the relationship are the values after removing the percentage signs of the mass percentages of elements Cr, C and Sr in the nickel - based superalloy; The Sr and Mg satisfy the relationship 0.05 < Sr + 12.5Mg < 0.12, where Sr and Mg are the values after removing the percentage signs of the mass percentages of elements Sr and Mg in the nickel - based superalloy.

2. The creep-resistant and oxidation-resistant nickel-based high-temperature alloy according to claim 1, characterized in that: The Cr, C and Sr satisfy the relationship 5.7 ≤ Cr - C / Sr ≤ 7.

1.

3. The creep-resistant and oxidation-resistant nickel-based high-temperature alloy according to claim 1, characterized in that: The Hf, Ta and C satisfy the relationship 0.18 < Hf / Ta - 2.25C < 0.56, where Hf, Ta and C are the values after removing the percentage signs of the mass percentages of elements Hf, Ta and C in the nickel - based superalloy.

4. The creep-resistant and oxidation-resistant nickel-based high-temperature alloy according to claim 3, characterized in that: The Hf, Ta and C satisfy the relationship 0.19 ≤ Hf / Ta - 2.25C ≤ 0.

47.

5. The creep-resistant and oxidation-resistant nickel-based high-temperature alloy according to claim 1, characterized in that: The Sr and Mg satisfy the relationship 0.06 ≤ Sr + 12.5Mg ≤ 0.

12.

6. The creep-resistant and oxidation-resistant nickel-based high-temperature alloy according to claim 1, characterized in that: Comprising: C: 0.08 - 0.16%; Cr: 7.3 - 8.9%; Co: 9.2 - 10.9%; W: 8.9 - 10.5%; Mo: 0.2 - 1.5%; Ta: 2.8 - 4.0%; Al: 4.3 - 6.2%; Ti: 0.4 - 2.5%; B: 0.012 - 0.025%; Hf: 1.4 - 2.4%; Zr: 0.003 - 0.008%; Mg ≤ 0.004%; Si ≤ 0.03%; Mn ≤ 0.04%; Sr: 0.04 - 0.08%; the balance being Ni and unavoidable impurities, by mass percentage.

7. Application of the creep - resistant and oxidation - resistant nickel - based superalloy according to any one of claims 1 - 6 in an aero - engine.

8. Application of the creep - resistant and oxidation - resistant nickel - based superalloy according to any one of claims 1 - 6 in a gas turbine.

9. The method for preparing the creep-resistant and oxidation-resistant nickel-based high-temperature alloy according to any one of claims 1 to 6, characterized in that: Comprising the following steps: (1) According to the alloy design ratio, add raw materials of Cr, Co, W, Mo, Ta, B, Hf, Zr, Mg, Si, Mn, Sr and part of C into a crucible, heat and melt under vacuum, and then carry out heat preservation treatment; After the heat preservation treatment in step (1) ends, add Al, Ti and the remaining C raw materials into the crucible, introduce argon, heat and melt under vacuum, and cast to obtain the nickel - based superalloy.

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