High-strength, high-toughness and fatigue-resistant nickel-based superalloy, its preparation method and application

Abstract

A high-strength, high-toughness and fatigue-resistant nickel-based superalloy disclosed in an embodiment of the present invention comprises: C: 0.02 to 0.12%; Cr: 9.5 to 11.5%; Co: 8.5 to 10.5%; W: 8.0 to 9.5%; Mo: 0.1 to 0.8%; Ta: 1.5 to 2.5%; Al: 3.5 to 5.5%; Ti: 0.3 to 1.8%; B: 0.008 to 0.02%; Hf: 1.5 to 2.5%; Zr: 0.002 to 0.007%; Mg: 0.001 to 0.008%; Si ≤ 0.15%; Mn ≤ 0.05%; Sr: 0.02 to 0.1%; Ba: 0.01 to 0.05%; Nd: 0.02 to 0.1%, and the balance is Ni and inevitable impurities, by mass percentage.

Description

Technical Field

[0001] The present invention belongs to the technical field of nickel-based superalloys, and particularly relates to a high-strength, high-toughness, fatigue-resistant nickel-based superalloy, and a preparation method and application thereof. Background Art

[0002] With the development of aeroengines and gas turbines, higher requirements are put forward for the fatigue performance of nickel-based superalloys. There are many factors affecting the fatigue performance of nickel-based superalloys, such as internal defects such as microvoids, carbides, residual eutectics, grain boundaries, surface defects caused by hot corrosion, coatings, crystal orientation, and external conditions. These factors will affect the stress distribution, dislocation movement, crack initiation and propagation behavior of nickel-based superalloys, thus affecting the low-cycle fatigue life of the alloy.

[0003] At present, the hot-end components of advanced aeroengines and gas turbines have the highest working conditions up to 1300°C, with complex stress actions and demanding requirements for alloy materials. Alloys that can meet the anti-fatigue performance will have problems with poor strength-toughness matching. There are almost no alloys among the existing high-temperature alloys at home and abroad that can fully meet the anti-fatigue performance and strength-toughness matching.

[0004] Therefore, how to prepare a high-temperature alloy that meets the use requirements of aeroengines and gas turbines has received more and more extensive attention. Summary of the Invention

[0005] The present invention is based on the inventor's discovery and recognition of the following facts and problems:

[0006] The high-temperature alloys used in the fields of advanced aeroengines, gas turbines, etc. are expected to achieve the following performance indicators: at room temperature, the tensile properties are Rm≥1150MPa, Rp0.2≥925MPa, A≥10.0%; at high temperature, the tensile properties are Rm≥900MPa, Rp0.2≥750MPa, A≥10.0% at 900°C, and the low-cycle fatigue cycles are greater than 4000 times at 950°C. However, the current high-temperature alloys cannot achieve the matching of low-cycle fatigue and strength-toughness, and there is still no high-temperature alloy that can meet the above requirements.

[0007] 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 high-strength, high-toughness, fatigue-resistant nickel-based superalloy, which has excellent mechanical properties, can meet the design and use requirements of aeroengines and gas turbines, and is suitable for components such as turbine blades that serve in the hot-end components of aeroengines and gas turbines for a long time.

[0008] The high-strength, high-toughness and fatigue-resistant nickel-based superalloy according to the embodiment of the present invention comprises: C: 0.02 to 0.12%; Cr: 9.5 to 11.5%; Co: 8.5 to 10.5%; W: 8.0 to 9.5%; Mo: 0.1 to 0.8%; Ta: 1.5 to 2.5%; Al: 3.5 to 5.5%; Ti: 0.3 to 1.8%; B: 0.008 to 0.02%; Hf: 1.5 to 2.5%; Zr: 0.002 to 0.007%; Mg: 0.001 to 0.008%; Si ≤ 0.15%; Mn ≤ 0.05%; Sr: 0.02 to 0.1%; Ba: 0.01 to 0.05%; Nd: 0.02 to 0.1%, and the balance is Ni and inevitable impurities, by mass percentage.

[0009] The advantages and technical effects brought by the high-strength, high-toughness and fatigue-resistant nickel-based superalloy according to the embodiment of the present invention are as follows: 1. In the embodiment of the present invention, while containing the Mg element, the Ba element is introduced, effectively improving the room-temperature tensile strength and elongation of the alloy, realizing a good match between strength and toughness. At the same time, Ba in the alloy can promote further deoxidation and desulfurization of the alloy, which is beneficial to the purification of the alloy; 2. In the embodiment of the present invention, the Sr element is introduced. The Sr element can significantly refine the grains, and at the same time, Sr can improve the oxidation resistance of the nickel-based superalloy; 3. In the embodiment of the present invention, 0.02 to 0.1% of the Nd element is introduced. Nd can combine with the Al element to form the high-temperature stable phase Al 11 Nd3, which can improve the creep rate and mechanical properties of the alloy. Adding Nd to the nickel-based alloy system containing the Mg element can form a dispersed distribution, high melting point and thermally stable particle phase Mg 12 Nd phase in the alloy, which plays a pinning role on the grains and improves the tensile strength and elongation of the alloy; 4. In the embodiment of the present invention, the alloy is composed of various elements with designed ratios. While endowing the nickel-based superalloy with excellent tensile properties and creep life, the density does not exceed 8.25 g / cm 3 , so the alloy has a light self-weight, which is beneficial to reducing the fuel consumption of aero-engines and improving the maneuverability, and at the same time can meet the requirement that the vibration of the gas turbine during operation is as small as possible, preventing the formation of vibration damage; 5. In the embodiment of the present invention, by controlling the amounts of various metal elements within a reasonable range, the nickel-based superalloy not only has excellent high-strength, high-toughness and high-temperature properties, but also has excellent low-cycle fatigue resistance, with excellent comprehensive properties, and can be applied to advanced aero-engines and gas turbines.

[0010] In some embodiments, Al, Nd and Mg satisfy the relationship 2.25 < Al - Nd / 12.7Mg < 4.25, where Al, Nd, and Mg are the values obtained by removing the percentage sign from the mass percentages of the elements Al, Nd, and Mg in the nickel-based superalloy.

[0011] In some embodiments, Al, Nd, and Mg satisfy the relational expression 3.10 ≤ (Al - Nd) / (12.7Mg) ≤ 4.15.

[0012] In some embodiments, Cr, Ba, and Sr satisfy the relational expression 3.85 < (Cr - 16.2Ba) / Sr < 5.12, where Cr, Ba, and Sr are the values obtained by removing the percentage signs from the mass percentage contents of elements Cr, Ba, and Sr in the nickel-based superalloy.

[0013] In some embodiments, Cr, Ba, and Sr satisfy the relational expression 3.90 ≤ (Cr - 16.2Ba) / Sr ≤ 4.9.

[0014] In some embodiments, Sr, Ba, and Nd satisfy the relational expression 0.07 < Sr + Ba + Nd < 0.18, where Sr, Ba, and Nd are the values obtained by removing the percentage signs from the mass percentage contents of elements Sr, Ba, and Nd in the nickel-based superalloy.

[0015] In some embodiments, Sr, Ba, and Nd satisfy the relational expression 0.09 ≤ Sr + Ba + Nd ≤ 0.17.

[0016] In some embodiments, the nickel-based superalloy comprises: C: 0.03 - 0.11%; Cr: 10.1 - 11.4%; Co: 8.6 - 10.2%; W: 8.2 - 9.4%; Mo: 0.2 - 0.7%; Ta: 1.6 - 2.3%; Al: 3.8 - 5.2%; Ti: 0.4 - 1.7%; B: 0.008 - 0.02%; Hf: 1.7 - 2.4%; Zr: 0.003 - 0.006%; Mg: 0.003 - 0.007%; Si ≤ 0.15%; Mn ≤ 0.05%; Sr: 0.02 - 0.09%; Ba: 0.01 - 0.04%; Nd: 0.02 - 0.09%, with the balance being Ni and unavoidable impurities.

[0017] The embodiments of the present invention further provide a method for preparing a nickel-based superalloy with high strength, high toughness, and fatigue resistance, comprising the following steps:

[0018] (1) According to the alloy design ratio, add the raw materials of Cr, Co, W, Mo, Ta, B, Hf, Zr, Mg, Si, Mn, Ba, Sr, Nd, and part of C into a crucible, heat and melt under vacuum, and then perform heat preservation treatment.

[0019] (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 under vacuum, and then cast to obtain the nickel-based superalloy.

[0020] The advantages and technical effects brought by the preparation method of the high-strength, high-toughness and fatigue-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. The alloy prepared by the method of the embodiments of the present invention not only has excellent strength and toughness properties and high-temperature properties, but also has excellent low-cycle fatigue resistance, and can meet the requirements of the design and use of advanced aero-engines and gas turbines.

[0021] The embodiments of the present invention also provide an application of a high-strength, high-toughness and fatigue-resistant nickel-based superalloy in the turbine blade of the hot-end component of an aero-engine or a gas turbine. The high-strength, high-toughness and fatigue-resistant nickel-based superalloy in the embodiments of the present invention has excellent strength and toughness properties, high-temperature properties and low-cycle fatigue resistance, and can be applied to the turbine blade of the hot-end component of an aero-engine or a gas turbine. Detailed implementation manners

[0022] The embodiments of the present invention will be described in detail below. The embodiments are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

[0023] The high-strength, high-toughness and fatigue-resistant nickel-based superalloy in the embodiments of the present invention includes: C: 0.02 - 0.12%; Cr: 9.5 - 11.5%; Co: 8.5 - 10.5%; W: 8.0 - 9.5%; Mo: 0.1 - 0.8%; Ta: 1.5 - 2.5%; Al: 3.5 - 5.5%; Ti: 0.3 - 1.8%; B: 0.008 - 0.02%; Hf: 1.5 - 2.5%; Zr: 0.002 - 0.007%; Mg: 0.001 - 0.008%; Si ≤ 0.15%; Mn ≤ 0.05%; Sr: 0.02 - 0.1%; Ba: 0.01 - 0.05%; Nd: 0.02 - 0.1%, and the balance is Ni and inevitable impurities, by mass percentage.

[0024] In the high-strength, high-toughness and fatigue-resistant nickel-based superalloy in the embodiments of the present invention, while containing the Mg element, the Ba element is introduced, which effectively improves the room-temperature tensile strength and elongation of the alloy, realizes a good match between strength and toughness, and at the same time, Ba can promote further deoxidation and desulfurization of the alloy in the alloy, which is beneficial to the purification of the alloy; in the embodiments of the present invention, the Sr element is introduced, and the Sr element can significantly refine the grains, and at the same time, Sr can improve the oxidation resistance of the nickel-based superalloy; in the embodiments of the present invention, 0.02 - 0.1% of the Nd element is introduced, and Nd can combine with the Al element to form Al 11The high-temperature stable phase of Nd3 can improve the creep rate and mechanical properties of the alloy. Adding Nd to the nickel-based alloy system containing Mg element can form dispersed, high-melting-point, and thermally stable particle phases Mg 12 in the Nd phase, which plays a pinning role on the grains and improves the tensile strength and elongation of the alloy. In the embodiments of the present invention, with the composition of each element designed in proportion, while endowing the nickel-based superalloy with excellent tensile properties and creep life, the density does not exceed 8.25 g / cm 3 , so the alloy has a light self-weight, which is beneficial to reducing the fuel consumption of aeroengines and improving the maneuverability, and can meet the requirement that the vibration of the gas turbine is as small as possible during operation to prevent the formation of vibration damage. In the embodiments of the present invention, by controlling the dosages of various metal elements within a reasonable range, the nickel-based superalloy not only has excellent high-strength and high-toughness properties and high-temperature properties, but also has excellent low-cycle fatigue resistance, with excellent comprehensive properties, and can be applied to advanced aeroengines and gas turbines

[0025] Among them, the functions of the main elements in the alloy of the embodiments of the present invention are as follows:

[0026] C plays a role in strengthening the grain boundaries in the nickel-based superalloy, which can delay the initiation, propagation, and coalescence of microcracks, thereby improving the high-temperature creep life of the alloy. In the embodiments of the present invention, the C content is controlled to be 0.02-0.12%.

[0027] Cr can improve the oxidation resistance of the alloy and has a solid-solution strengthening effect. After aging treatment, it can also combine with C to form granular M 23 C6 distributed along the grain boundaries, playing a role in strengthening the grain boundaries. However, when the Cr content is too high, it is easy to form the TCP phase, reducing the long-term tissue performance stability of the alloy. In the embodiments of the present invention, the Cr content is controlled to be 9.5-11.5%.

[0028] Co is an important solid-solution strengthening element and precipitation strengthening element, providing good solid-solution strengthening effect for the alloy, significantly reducing the stacking fault energy of the matrix, broadening the width of the extended dislocation, making it difficult for dislocations to bunch and cross-slip, thereby improving the creep resistance and creep life of the alloy; Co can also partially replace the elements in the Ni3Al-type phase precipitation strengthening phase to improve the stability of the phase during long-term service. In the embodiments of the present invention, the content of Co is controlled to be 8.5-10.5%.

[0029] W and Mo are one of the main solid-solution strengthening elements. They can be dissolved in both the alloy matrix and the γ'-strengthening phase, and at the same time can increase the interatomic binding force, raise the diffusion activation energy and the recrystallization temperature, thereby effectively improving the high-temperature strength. In the embodiments of the present invention, the W content is controlled to be 8.0-9.5%, and the Mo content is controlled to be 0.1-0.8%.

[0030] Al, Ti, and Ta are the forming elements of the strengthening phase γ′ in nickel-based alloys. Generally, it is considered that with the increase of the content of these three elements, the number of γ′ increases, and the high-temperature creep and stress rupture properties are improved. However, excessive γ′ will deteriorate the processing performance. In the embodiments of the present invention, Al is controlled to be 3.5 - 5.5%, Ti is controlled to be 0.3 - 1.8%, and Ta is controlled to be 1.5 - 2.5%.

[0031] The atomic radius of B is very small and it is easy to enrich at the grain boundaries, preventing the harmful low-melting-point elements from segregating at the grain boundaries, thus improving the grain boundary bonding force. The borides on the grain boundaries can prevent grain boundary slip, void initiation, and expansion, which is beneficial to improving the creep resistance and stress rupture life of the alloy. In the embodiments of the present invention, the B content is controlled to be 0.008 - 0.020%.

[0032] Zr can purify the grain boundaries and enhance the grain boundary bonding force. However, excessive Zr is likely to reduce the processing performance. In the embodiments of the present invention, Zr is controlled to be 0.002 - 0.007%.

[0033] Mg atoms segregate at the grain boundaries, which can improve the grain boundary bonding force and increase the grain boundary strength. Mg atoms not only segregate at the grain boundaries but also at the carbide phase boundaries and γ` phase boundaries. Mg atoms can also enter γ` and carbides, which is beneficial to improving the mechanical properties. In the embodiments of the present invention, the Mg content is controlled to be 0.001 - 0.008%.

[0034] Ba can significantly refine the as-cast structure of the alloy, break part of the network-like β phase, and distribute it in small pieces at the grain boundaries, and the alloy grain refinement effect is significant. After adding Ba to the Mg-containing nickel-based alloy, the room-temperature tensile strength and elongation of the alloy can be improved simultaneously, achieving an excellent strength-ductility match. Ba can promote further deoxidation and desulfurization of the alloy in the alloy, making the alloy pure. In the embodiments of the present invention, the Ba content is controlled to be 0.01 - 0.05%.

[0035] Sr can significantly refine the grains, and the alloy grain size decreases with the increase of the Sr content. Sr can improve the oxidation resistance of the alloy, and its oxidation resistance shows an increasing trend with the increase of the Sr addition amount. However, with the addition of Sr, a compound phase distributed in a network along the grain boundaries appears in the alloy, increasing the brittleness of the as-cast alloy. With the increase of the Sr content, both the strength and elongation of the as-cast alloy decrease. Therefore, in the embodiments of the present invention, the Sr content is controlled to be 0.02 - 0.1%.

[0036] Nd element can refine the grains and can form the high-temperature stable phase Al 11 Nd3 with Al element, which can improve the steady-state creep rate and mechanical properties of the alloy at 200°C. Adding Nd to the Mg-containing nickel-based alloy can form dispersed, high-melting-point, and thermally stable particle phases Mg 12The Nd phase pins the grains, improving the tensile strength and elongation of the alloy. In the embodiments of the present invention, the Nd content is controlled to be 0.02 - 0.1%.

[0037] In some embodiments, preferably, the Al, Nd, and Mg satisfy the relation 2.25 < Al - Nd / 12.7Mg < 4.25, where Al, Nd, and Mg are the values obtained by removing the percentage signs from the mass percentage contents of the elements Al, Nd, and Mg in the nickel-based superalloy. Further preferably, the Al, Nd, and Mg satisfy the relation 3.10 ≤ Al - Nd / 12.7Mg ≤ 4.15.

[0038] In the embodiments of the present invention, it is defined that the Al, Nd, and Mg satisfy the relation 2.25% < Al - Nd / 12.7Mg < 4.25%, which greatly improves the strength of the alloy and simultaneously improves the low-cycle fatigue resistance of the nickel-based superalloy.

[0039] In some embodiments, preferably, the Cr, Ba, and Sr satisfy the relation 3.85 < Cr - 16.2Ba / Sr < 5.12, where Cr, Ba, and Sr are the values obtained by removing the percentage signs from the mass percentage contents of the elements Cr, Ba, and Sr in the nickel-based superalloy. Further preferably, the Cr, Ba, and Sr satisfy the relation 3.90 ≤ Cr - 16.2Ba / Sr ≤ 4.9.

[0040] In the embodiments of the present invention, it is defined that the Cr, Ba, and Sr satisfy the relation 3.85 < Cr - 16.2Ba / Sr < 5.12, which is beneficial to the matching of the strength and toughness of the nickel-based superalloy.

[0041] In some embodiments, preferably, the Sr, Ba, and Nd satisfy the relation 0.07 < Sr + Ba + Nd < 0.18, where Sr, Ba, and Nd are the values obtained by removing the percentage signs from the mass percentage contents of the elements Sr, Ba, and Nd in the nickel-based superalloy. Further preferably, the Sr, Ba, and Nd satisfy the relation 0.09 ≤ Sr + Ba + Nd ≤ 0.17.

[0042] In the embodiments of the present invention, the elements Sr, Ba, and Nd all have the effect of refining grains. Defining that the Sr, Ba, and Nd elements satisfy 0.07 < Sr + Ba + Nd < 0.18 can control the grains of the alloy within a suitable range and will not affect the tensile strength and elongation of the alloy due to excessive element contents.

[0043] In some embodiments, preferably, the high-strength, high-toughness and fatigue-resistant nickel-based superalloy comprises: C: 0.03 to 0.11%; Cr: 10.1 to 11.4%; Co: 8.6 to 10.2%; W: 8.2 to 9.4%; Mo: 0.2 to 0.7%; Ta: 1.6 to 2.3%; Al: 3.8 to 5.2%; Ti: 0.4 to 1.7%; B: 0.008 to 0.02%; Hf: 1.7 to 2.4%; Zr: 0.003 to 0.006%; Mg: 0.003 to 0.007%; Si ≤ 0.15%; Mn ≤ 0.05%; Sr: 0.02 to 0.09%; Ba: 0.01 to 0.04%; Nd: 0.02 to 0.09%, and the balance is Ni and unavoidable impurities.

[0044] An embodiment of the present invention also provides a method for preparing a high-strength, high-toughness and fatigue-resistant nickel-based superalloy, comprising the following steps:

[0045] (1) According to the alloy design ratio, add Cr, Co, W, Mo, Ta, B, Hf, Zr, Mg, Si, Mn, Ba, Sr, Nd and a part of C raw materials into a crucible, heat and melt under vacuum conditions, and then carry out heat preservation treatment;

[0046] (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 under vacuum conditions, and then cast to obtain a nickel-based superalloy.

[0047] In the method for preparing a high-strength, high-toughness and fatigue-resistant nickel-based superalloy according to the embodiment of the present invention, adding the easily burned C element step by step is beneficial to removing gases in the alloy and improving the mechanical properties of the alloy; the alloy prepared according to the embodiment of the present invention not only has excellent strength and toughness properties and high-temperature properties, but also has excellent low-cycle fatigue resistance, and can meet the requirements of the design and use of advanced aeroengines and gas turbines.

[0048] In some embodiments, preferably, in step (1), the part of C raw materials is 8 to 25% of the designed dosage of C raw materials, the heat preservation temperature is 1600 °C to 1650 °C, and the heat preservation time is 10 to 30 min; in step (2), the introduction amount of argon is based on making the air pressure in the crucible -0.02 to -0.1 MPa; the vacuum degree of the vacuum condition is < 0.1 Pa, and the casting temperature is ≥ 1560 °C.

[0049] The embodiments of the present invention also provide an application of a nickel-based superalloy with high strength, high toughness and fatigue resistance in the turbine blade of the hot end component of an aeroengine or a gas turbine. The nickel-based superalloy with high strength, high toughness and fatigue resistance in the embodiments of the present invention has excellent strength and toughness properties, high temperature properties and low cycle fatigue resistance, and can be applied to the turbine blade of the hot end component of an aeroengine or a gas turbine.

[0050] The technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0051] Example 1

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

[0053] (2) Add Al, Ti and the remaining C raw materials into the crucible; at the same time, fill the furnace with argon gas until the pressure is -0.02 MPa, heat and melt under the condition that the vacuum degree is less than 0.1 Pa, tap the steel at 1560 °C for casting, cool to room temperature, demold and perform surface sandblasting and grinding to remove the oxide scale to obtain the nickel-based superalloy.

[0054] Examples 2 to 8

[0055] The preparation methods of Examples 2 to 8 are the same as those of Example 1, except that the alloy compositions are different. The alloy compositions prepared in Examples 1 to 8 are shown in Table 1, and the performances are shown in Table 2.

[0056] Comparative Example 1

[0057] The preparation method of Comparative Example 1 is the same as that of Example 1, except that the alloy composition is different: the alloy does not contain the element Sr, and the performance data of the alloy prepared in Comparative Example 1 are shown in Table 2.

[0058] Comparative Example 2

[0059] The preparation method of Comparative Example 2 is the same as that of Example 1, except that the alloy composition is different: the content of the element Sr in the alloy is 0.15%, and the performance data of the alloy prepared in Comparative Example 2 are shown in Table 2.

[0060] Comparative Example 3

[0061] The preparation method of Comparative Example 3 is the same as that of Example 1, except that the alloy composition is different: the content of the element Cr in the alloy is 12.5%, and the performance data of the alloy prepared in Comparative Example 3 are shown in Table 2.

[0062] Comparative Example 4

[0063] The preparation method of Comparative Example 4 is the same as that of Example 1, except that the alloy composition is different: the alloy does not contain element Ba. The performance data of the alloy obtained in Comparative Example 4 are shown in Table 2.

[0064] Comparative Example 5

[0065] The preparation method of Comparative Example 5 is the same as that of Example 1, except that the alloy composition is different: the content of Ba element in the alloy is 0.08. The performance data of the alloy obtained in Comparative Example 5 are shown in Table 2.

[0066] Table 1

[0067]

[0068]

[0069] Table 2

[0070]

[0071]

[0072] Note: Low cycle fatigue is at 950 °C, the stress for tension and compression is 600 MPa, the mean stress is 0, the stress ratio is -1, the waveform is a triangular wave, one cycle of tension and compression is one cycle, until the number of cycles at fracture failure. The more the number of cycles, the better the fatigue resistance of the material.

[0073] From the data in the above table, it can be seen that the nickel-based superalloys obtained in Examples 1 to 8 have very good tensile properties at room temperature and 900 °C. At room temperature, the tensile properties are Rm≥1150 MPa, Rp0.2≥925 MPa, A≥10.0%; at 900 °C high temperature tensile, Rm≥900 MPa, Rp0.2≥750 MPa, A≥10.0%, and the low cycle fatigue at 950 °C is more than 4000 times, which can meet the use requirements of superalloys in fields such as aeroengines and gas turbines. In particular, when the relationship 2.25 < Al-Nd / 12.7Mg < 4.25, 3.85 < Cr-16.2Ba / Sr < 5.12 and 0.07 < Sr+Ba+Nd < 0.18 is satisfied, such as in Examples 4 to 8, the nickel-based superalloys have more excellent properties.

[0074] Comparative Example 1 does not contain element Sr, resulting in a significant decrease in the elongation A of the nickel-based superalloy obtained in Comparative Example 1 at room temperature and 900 °C, and the tensile strength also decreases. At the same time, the low cycle fatigue performance at 950 °C is reduced to 3561 times; in Comparative Example 2, the content of element Sr is too high. Although the low cycle fatigue performance at 950 °C can be maintained above 4000 times, the tensile strength and elongation A of the alloy at room temperature and 900 °C both decrease significantly, and cannot meet the use requirements.

[0075] In Comparative Example 3, the content of element Cr was adjusted. Although the high-cycle fatigue performance at 950 °C was improved and could reach 4120 cycles, the tensile performance decreased, especially the high-temperature tensile strength and elongation at 900 °C decreased significantly, failing to meet the usage requirements.

[0076] In Comparative Example 4, Ba element was not added, resulting in a significant decrease in the tensile strength of the nickel-based superalloy prepared in Comparative Example 4 at room temperature and 900 °C, and the elongation A also decreased slightly; in Comparative Example 5, too much Ba element was added. Although the strength of the alloy could be maintained at a relatively high level, the elongation decreased significantly, and the low-cycle fatigue performance at 950 °C decreased to 3986 cycles, failing to meet the usage requirements.

[0077] In the present invention, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0078] Although the above embodiments have been shown and described, it can be understood that the above embodiments are exemplary and should not be construed as limitations on the present invention. Any changes, modifications, substitutions, and variations made by those of ordinary skill in the art to the above embodiments are within the protection scope of the present invention.

Claims

1. A high-strength, high-toughness and fatigue-resistant nickel-based superalloy, characterized in that, Comprising: C: 0.02 - 0.12%; Cr: 9.5 - 11.5%; Co: 8.5 - 10.5%; W: 8.0 - 9.5%; Mo: 0.1 - 0.8%; Ta: 1.5 - 2.5%; Al: 3.5 - 5.5%; Ti: 0.3 - 1.8%; B: 0.008 - 0.02%; Hf: 1.5 - 2.5%; Zr: 0.002 - 0.007%; Mg: 0.001 - 0.008%; Si ≤ 0.15%; Mn ≤ 0.05%; Sr: 0.02 - 0.1%; Ba: 0.01 - 0.05%; Nd: 0.02 - 0.1%, the balance being Ni and unavoidable impurities, by mass percentage; The Al, Nd and Mg satisfy the relationship 2.25 < Al - Nd / 12.7Mg < 4.25, where Al, Nd, and Mg are the values of the mass percentages of elements Al, Nd, and Mg in the nickel-based superalloy after removing the percentage signs.

2. The high-strength, high-toughness and fatigue-resistant nickel-based superalloy according to claim 1, wherein The Al, Nd and Mg satisfy the relationship 3.10 ≤ Al - Nd / 12.7Mg ≤ 4.

15.

3. The high-strength, high-toughness and fatigue-resistant nickel-based superalloy according to claim 1, wherein, The Cr, Ba and Sr satisfy the relationship 3.85 < Cr - 16.2Ba / Sr < 5.12, where Cr, Ba, and Sr are the values of the mass percentages of elements Cr, Ba, and Sr in the nickel-based superalloy after removing the percentage signs.

4. The high-strength, high-toughness and fatigue-resistant nickel-based superalloy according to claim 3, characterized in that, The Cr, Ba and Sr satisfy the relationship 3.90 ≤ Cr - 16.2Ba / Sr ≤ 4.

9.

5. The high-strength, high-toughness and fatigue-resistant nickel-based superalloy according to claim 1, wherein The Sr, Ba and Nd satisfy the relationship 0.07 < Sr + Ba + Nd < 0.18, where Sr, Ba, and Nd are the values of the mass percentages of elements Sr, Ba, and Nd in the nickel-based superalloy after removing the percentage signs.

6. The high-strength, high-toughness and fatigue-resistant nickel-based superalloy according to claim 5, characterized in that, The Sr, Ba and Nd satisfy the relationship 0.09 ≤ Sr + Ba + Nd ≤ 0.

17.

7. The nickel-based superalloy with high strength, high toughness and fatigue resistance according to claim 1, characterized in that, The nickel-based superalloy comprises: C: 0.03 - 0.11%; Cr: 10.1 - 11.4%; Co: 8.6 - 10.2%; W: 8.2 - 9.4%; Mo: 0.2 - 0.7%; Ta: 1.6 - 2.3%; Al: 3.8 - 5.2%; Ti: 0.4 - 1.7%; B: 0.008 - 0.02%; Hf: 1.7 - 2.4%; Zr: 0.003 - 0.006%; Mg: 0.003 - 0.007%; Si ≤ 0.15%; Mn ≤ 0.05%; Sr: 0.02 - 0.09%; Ba: 0.01 - 0.04%; Nd: 0.02 - 0.09%, the balance being Ni and unavoidable impurities.

8. The preparation method of the high-strength, high-toughness and fatigue-resistant nickel-based superalloy according to any one of claims 1 to 7, characterized in that, Comprising the following steps: (1) According to the alloy design ratio, add Cr, Co, W, Mo, Ta, B, Hf, Zr, Mg, Si, Mn, Ba, Sr, Nd and part of the C raw materials into the crucible, heat and melt them under vacuum, and then carry out heat preservation treatment; (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.

9. Application of the nickel-based superalloy with high strength, high toughness and fatigue resistance according to any one of claims 1 to 7 in the turbine blade of the hot-end component of an aeroengine or a gas turbine.

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