A nickel-based wrought superalloy and method of making the same

Abstract

The application relates to a nickel-based wrought superalloy and a preparation method thereof, and relates to the technical field of wrought superalloys, wherein the chemical composition of the nickel-based wrought superalloy comprises the following components in percentage by weight: C: 0.01-1 wt%; Al: 1-8 wt%; Co: 5-25 wt%; W: 1-5 wt%; Cr: 8-18 wt%; Mo: 1-8 wt%; Nb: 1-5 wt%; Ti: 1-3 wt%; V: 0.1-1 wt%; Hf: 0.1-2 wt%; and the balance is Ni. The sum of the weight percentages of the precipitation strengthening elements Al, Ti and Nb in the alloy is greater than or equal to 7 wt%; the weight percentage ratio of the Ti element to the Al element is 0.2-1, so that the high-temperature strength and the endurance performance of the alloy are ensured; meanwhile, the size and the morphology of the gamma prime phase are improved by adding a certain amount of Hf element, so that the hot working plasticity of the alloy is improved, and the problem that the existing nickel-based wrought superalloy cannot simultaneously meet the service performance and the hot deformation capacity is solved.

Description

Technical Field

[0001] This invention relates to the field of wrought superalloy technology, and in particular to a nickel-based wrought superalloy and its preparation method. Background Technology

[0002] Nickel-based wrought superalloys possess excellent temperature resistance and mechanical properties, and are widely used in the manufacture of turbine disks and blades for aero engines, as well as components for marine equipment. With the iterative development of aero engines, the performance requirements for superalloys used in engines are becoming increasingly stringent.

[0003] One of the most effective methods to improve the heat resistance of deformed superalloys is to increase the γ′ phase content. However, as the γ′ phase content increases, the alloy's deformation resistance increases, making single-pass forging difficult and the forging process increasingly complex, significantly reducing production efficiency and increasing production costs. Simultaneously, the deformed alloy exhibits a coarse and uneven microstructure, severely impacting its applications.

[0004] In summary, existing nickel-based wrought superalloys have the problem of not being able to simultaneously meet the requirements of service performance and hot deformation capability. Summary of the Invention

[0005] In view of this, the present invention provides a nickel-based wrought superalloy and its preparation method, the main purpose of which is to solve the problem that existing nickel-based wrought superalloys cannot simultaneously meet the requirements of service performance and hot deformation capability.

[0006] To achieve the above objectives, the present invention mainly provides the following technical solutions:

[0007] On one hand, embodiments of the present invention provide a nickel-based wrought superalloy, wherein the chemical composition of the nickel-based wrought superalloy comprises, by weight percentage:

[0008] C: 0.01–1 wt%; Al: 1–8 wt%; Co: 5–25 wt%; W: 1–5 wt%; Cr: 8–18 wt%; Mo: 1–8 wt%; Nb: 1–5 wt%; Ti: 1–3 wt%; V: 0.1–1 wt%; Hf: 0.1–2 wt%; balance Ni;

[0009] In the nickel-based wrought superalloy, the sum of the weight percentages of Al, Ti, and Nb is ≥7wt%.

[0010] In the nickel-based wrought superalloy, the weight percentage ratio of Ti to Al is 0.2 to 1.

[0011] Preferably, the chemical composition of the nickel-based wrought superalloy includes:

[0012] C: 0.01–0.2 wt%; Al: 1–7.6 wt%; Co: 5–23 wt%; W: 1–5 wt%; Cr: 8–18 wt%; Mo: 1–8 wt%; Nb: 1–5 wt%; Ti: 1–3 wt%; V: 0.1–1 wt%; Hf: 0.1–1.5 wt%; balance Ni.

[0013] Preferably, the carbides in the nickel-based wrought superalloy include M 23 C6 carbides and MC carbides; among which, M 23 C6 carbides are discontinuous chains, nanometer-sized, and distributed at grain boundaries; MC are irregular blocks, micrometer-sized, and distributed within grains.

[0014] Preferably, the grain size of the nickel-based wrought superalloy is higher than grade 8; and / or the volume fraction of the γ′ phase in the nickel-based wrought superalloy is 20-50%; and / or the size of the γ′ phase at the grain boundaries in the nickel-based wrought superalloy is ≥500 nm; preferably, the size of the γ′ phase at the grain boundaries is 500 nm to 2 μm; preferably, the volume fraction of the γ′ phase at the grain boundaries is 20-50%; and / or the size of the γ′ phase within the grains in the nickel-based wrought superalloy is 50-500 nm.

[0015] Preferably, the preparation method of the nickel-based wrought superalloy includes the following steps:

[0016] Step 1) The raw materials are subjected to vacuum induction furnace melting, electroslag remelting, and vacuum consumable remelting, and then cast into alloy ingots.

[0017] Step 2) The alloy ingot is subjected to homogenization diffusion annealing treatment to obtain the diffusion annealed ingot.

[0018] Step 3) The ingot after diffusion annealing is subjected to heat treatment to spheroidize and coarsen the γ′ phase, so as to obtain the heat-treated ingot.

[0019] Step 4) The heat-treated ingot is subjected to a blanking forging process to obtain a nickel-based wrought high-temperature alloy.

[0020] Preferably, the vacuum induction furnace smelting process includes sequentially performing full melting, refining, and tapping on the raw materials to obtain molten steel; more preferably, the temperature range of the full melting process is 1480–1580℃, and the vacuum degree is 0–35 Pa; the temperature of the refining process is 1480–1580℃, and the vacuum degree is ≤8 Pa; the temperature range of the tapping process is 1400–1450℃.

[0021] Preferably, the chemical composition of the electroslag used in the electroslag remelting process, by weight percentage, includes:

[0022] CaF2: 35-45%; Al2O3: 15-30%; CaO: 10-25%; MgO: 0-5%; TiO2: balance;

[0023] Preferably, during the electroslag remelting process: the argon flow rate is 50-100 L / min; the slag resistance sway setting range is 0.1-0.6 mohm; the melting rate control range is 2.5-9.0 kg / min; and the water temperature control range is 30-60℃.

[0024] Preferably, the control parameters for the vacuum arc remelting process are set as follows: melting rate control range is 2.5~4kg / min; helium pressure control range is 300~650Pa; vacuum degree during the smelting stabilization stage is ≤1.5Pa; cooling water temperature control range is 15~30℃;

[0025] Preferably, in step 2):

[0026] The alloy ingot is heated to T1 and held at T1 for a first set time; then, it is heated to T2 and held at T2 for a second time; finally, it is cooled to room temperature to obtain the ingot after diffusion annealing.

[0027] Where T1 is T m +(5~50℃); T2 is T m +(20~70℃); T m The temperature at which the γ′ phase of a nickel-based wrought superalloy completely dissolves;

[0028] Preferably, the heating rate of the alloy ingot to T1 is 5-15°C / min;

[0029] Preferably, the first set time is 5 to 20 hours;

[0030] Preferably, the second set time is 10 to 45 hours;

[0031] Preferably, the heating rate from T1 to T2 is 5–25 °C / min.

[0032] Preferably, the volume fraction of the γ′ phase in the ingot after diffusion annealing is not less than 20%.

[0033] Preferably, in step 3):

[0034] The temperature of the heat treatment is T. m -(20~70℃);

[0035] Preferably, the heating rate of the ingot after diffusion annealing to the heat treatment temperature is 5-15°C / min;

[0036] Preferably, the holding time at the heat treatment temperature is 8 to 72 hours.

[0037] Preferably, in step 3):

[0038] In the ingot after diffusion annealing, the γ′ phase has a size of 50 nm to 800 nm and an irregular cubic shape; and / or

[0039] In the heat-treated ingot, the γ′ phase has a size of 50 nm to 2 μm, a spherical shape, and a volume fraction of 20% to 50%.

[0040] Preferably, in step 4):

[0041] The forging process is a single-pass forging process.

[0042] Preferably, in the single-pass forging process, the deformation temperature is 1050-1140℃, the holding time is 1-2h, and the strain rate is 0.5-0.05 / s; when the deformation is 30-60%, the ingot does not crack.

[0043] Compared with the prior art, the nickel-based wrought superalloy and its preparation method of the present invention have at least the following beneficial effects:

[0044] On one hand, embodiments of the present invention provide a nickel-based wrought superalloy. By controlling the content of key elements in the alloy (e.g., in the nickel-based wrought superalloy, the sum of the weight percentages of Al, Ti, and Nb is ≥7 wt%; the weight percentage ratio of Ti to Al is 0.2–1), the precipitation strengthening and solid solution strengthening effects of the alloy are improved, ensuring high high-temperature strength and creep resistance. Furthermore, the precipitation of grain boundary carbides and γ′ phases enhances the interfacial bonding force of the alloy, which is beneficial to improving the alloy's strength. This is advantageous for the alloy's creep fracture strength, creep ductility, and low-cycle fatigue. The pinning effect of grain boundary precipitation on grain boundaries can inhibit grain boundary diffusion and grain growth, thereby improving the mechanical properties and microstructure stability of the alloy. In addition, based on the design of other elements and their contents, the present invention also adds Hf element to enhance the strengthening effect of the γ′ phase, improving the strength and plasticity of the alloy. In summary, the synergistic effect between the above alloy components solves the problem that existing nickel-based wrought superalloys cannot simultaneously meet the requirements of service performance and hot deformation capability.

[0045] On the other hand, embodiments of the present invention provide a method for preparing a nickel-based wrought superalloy. This method involves heat treatment to increase the γ′ phase from the nanoscale to the microscale. Specifically, the ingot after diffusion annealing is heat-treated. By designing the heat treatment process parameters, the γ′ phase is spheroidized and coarsened (the addition of Hf element and the heat treatment process in this invention promote γ′ phase growth). The resulting micron-sized γ′ phase in the heat-treated ingot provides recrystallization nucleation sites, promoting dynamic recrystallization during hot deformation, refining the grains, reducing deformation resistance, and ensuring rapid billet formation without cracking. This method is less dependent on the preparation conditions, simpler, and more efficient. The nickel-based wrought superalloy obtained after billet formation has a γ-γ′ dual-phase structure, with small and uniform grain size and microstructure. It exhibits good thermoplasticity, which is beneficial for subsequent forming and heat treatment performance control.

[0046] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0047] Figure 1 The metallographic morphology of the nickel-based wrought superalloy obtained in Example 1 is shown.

[0048] Figure 2 The image shows the SEM microstructure of the nickel-based wrought superalloy obtained in Example 1.

[0049] Figure 3 The metallographic morphology of the nickel-based wrought superalloy obtained in Comparative Example 1 is shown.

[0050] Figure 4 The SEM microstructure of the nickel-based wrought superalloy obtained in Comparative Example 1 is shown. Detailed Implementation

[0051] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the specific embodiments, structures, features, and effects according to the present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments. In the following description, different "embodiments" or "embodiments" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0052] This invention addresses the problem that existing nickel-based wrought superalloys struggle to simultaneously meet both service performance and hot deformation requirements. This invention allows for rapid billet preparation, resulting in a uniform microstructure and excellent plasticity, further promoting the development of nickel-based wrought superalloys. The specific details of this invention are as follows:

[0053] On one hand, embodiments of the present invention provide a nickel-based wrought superalloy, wherein, by weight percentage, the chemical composition of the nickel-based wrought superalloy includes:

[0054] C: 0.01–1 wt%; Al: 1–8 wt%; Co: 5–25 wt%; W: 1–5 wt%; Cr: 8–18 wt%; Mo: 1–8 wt%; Nb: 1–5 wt%; Ti: 1–3 wt%; V: 0.1–1 wt%; Hf: 0.1–2 wt%; balance Ni.

[0055] In the nickel-based wrought superalloy, the sum of the weight percentages of Al, Ti, and Nb is ≥7 wt%; the weight percentage ratio of Ti to Al is 0.2–1. It should be noted that the alloy misfit degree decreases with increasing Ti / Al ratio. The absolute value of the misfit degree is what contributes to precipitation strengthening; when the misfit degree is close to 0, the γ′ phase is stable, which is beneficial for high-temperature creep resistance.

[0056] Preferably, the chemical composition of the nickel-based wrought superalloy, by weight percentage, includes:

[0057] C: 0.01–0.2 wt%; Al: 1–7.6 wt%; Co: 5–23 wt%; W: 1–5 wt%; Cr: 8–18 wt%; Mo: 1–8 wt%; Nb: 1–5 wt%; Ti: 1–3 wt%; V: 0.1–1 wt%; Hf: 0.1–1.5 wt%; balance Ni.

[0058] The following points need to be clarified regarding the above plan:

[0059] (1) Compared with conventional nickel-based wrought superalloys, this invention adds higher contents of Al, Ti, and Nb elements, which are the main forming elements of precipitation strengthening phase (γ′ phase) in superalloys. Therefore, the volume fraction of γ′ phase in the alloy reaches 30-50%, thereby giving the alloy higher temperature resistance and mechanical properties. The alloy can withstand temperatures up to 750℃. In the microstructure of the superalloy of this invention, the intragranular γ′ phase with a size of 50-500 nm ensures the intragranular strength of the alloy; discontinuous chain-like M atoms are distributed at the grain boundaries. 23 C6 carbides and γ′ phases with a size of 500 nm to 2 μm play a role in grain boundary strengthening, achieving coordinated strengthening of grain boundaries and grains.

[0060] (2) Due to the extremely high alloying degree and γ′ phase content of highly alloyed wrought high-temperature alloys, their deformation resistance is significantly increased while their thermoplasticity is significantly decreased. This makes them prone to cracking and structural instability during hot deformation, posing significant challenges to forging. This invention adds Hf element and combines it with heat treatment processes to increase at least a portion of the γ′ phase from the nanometer scale to the micrometer scale. Specifically, the ingot after diffusion annealing is heat-treated at T... m The temperature is set at 20–70°C, with a heating rate of 5–15°C / min and a holding time of 8–72 h to induce spheroidization and coarsening of the γ′ phase. This invention promotes γ′ phase growth by adding Hf. The resulting micron-sized γ′ phase in the heat-treated ingot provides recrystallization nucleation sites, promoting dynamic recrystallization during hot deformation, refining the grains, reducing deformation resistance, ensuring rapid billet formation without cracking, and exhibiting low dependence on preparation conditions, simple process, and high production efficiency.

[0061] On the other hand, embodiments of the present invention provide a method for preparing a nickel-based wrought superalloy, which includes the following steps:

[0062] Step 1) The raw materials are subjected to vacuum induction furnace melting, electroslag remelting, and vacuum consumable remelting, and then cast into alloy ingots.

[0063] Preferably, the vacuum induction furnace smelting process includes sequentially performing full melting, refining, and tapping on the raw materials to obtain molten steel; more preferably, the temperature range of the full melting process is 1480–1580℃, and the vacuum degree is 0–35 Pa; the temperature of the refining process is 1480–1580℃, and the vacuum degree is ≤8 Pa; the temperature range of the tapping process is 1400–1450℃.

[0064] Preferably, the chemical composition of the electroslag used in the electroslag remelting process, by weight percentage, includes:

[0065] CaF2: 35-45%; Al2O3: 15-30%; CaO: 10-25%; MgO: 0-5%; TiO2: balance;

[0066] Preferably, during the electroslag remelting process: the argon flow rate is 50-100 L / min; the slag resistance sway setting range is 0.1-0.6 mohm; the melting rate control range is 2.5-9.0 kg / min; and the water temperature control range is 30-60℃.

[0067] Preferably, the control parameters for the vacuum arc remelting process are set as follows: melting rate control range is 2.5~4kg / min; helium pressure control range is 300~650Pa; vacuum degree during the smelting stabilization stage is ≤1.5Pa; cooling water temperature control range is 15~30℃;

[0068] Step 2) The alloy ingot is subjected to homogenization diffusion annealing treatment to obtain the diffusion annealed ingot.

[0069] Step 3) The ingot after diffusion annealing is subjected to heat treatment to make the γ′ phase spheroidized and coarsened (promoting the growth of the γ′ phase, the grown γ′ phase can promote dynamic recrystallization, reduce the deformation resistance of the alloy and refine the grains) to obtain the heat-treated ingot.

[0070] Step 4) The heat-treated ingot is subjected to a blanking forging process to obtain a nickel-based wrought high-temperature alloy.

[0071] Preferably, in step 2): the alloy ingot is heated to T1 at a heating rate of 5-15°C / min and held at T1 for a first set time; then, it is heated to T2 and held at T2 for a second time; finally, it is cooled to room temperature to obtain the ingot after diffusion annealing.

[0072] Where T1 is T m +(5~50℃); T2 is T m +(20~70℃); T m The temperature at which the γ′ phase of a nickel-based wrought superalloy completely dissolves;

[0073] Preferably, the first set time is 5 to 20 hours;

[0074] Preferably, the second set time is 10 to 45 hours;

[0075] Preferably, the heating rate from T1 to T2 is 5 to 25 °C / min (too rapid heating will increase the temperature gradient inside and on the surface of the material, thereby generating greater internal stress).

[0076] Preferably, the γ′ phase content in the ingot after diffusion annealing is not less than 20%.

[0077] Preferably, in step 3), the temperature of the heat treatment is T. m - (20~70℃), the heating rate is 5~15℃ / min, to avoid the alloy heating too fast, which would increase the temperature gradient inside and on the surface of the ingot and thus generate large internal stress; preferably, the holding time at the heat treatment temperature is 8~72h.

[0078] Preferably, in step 3), the size of the γ′ phase in the heat-treated ingot is 50 nm-2 μm.

[0079] Preferably, in step 4):

[0080] The forging process is a single-pass forging process.

[0081] Preferably, in single-pass forging, when the deformation temperature is 1050-1140℃, the holding time is 1-2h, the strain rate is 0.5-0.05 / s, and the deformation amount is 30-60%, the ingot will not crack.

[0082] The present invention will be further described in detail below with reference to specific embodiments, but the scope of protection of the present invention is not limited to the content described.

[0083] In the following embodiments, the chemical composition of the nickel-based wrought superalloy, by mass percentage, includes:

[0084] C: 0.01–1 wt%; Al: 1–8 wt%; Co: 5–25 wt%; W: 1–5 wt%; Cr: 8–18 wt%; Mo: 1–8 wt%; Nb: 1–5 wt%; Ti: 1–3 wt%; V: 0.1–1 wt%; Hf: 0.1–2 wt%; balance Ni.

[0085] The alloy composition and content of the embodiments of the present invention are shown in Table 1:

[0086] Table 1 (wt%)

[0087]

[0088]

[0089] Example 1

[0090] This embodiment designs a nickel-based wrought superalloy, the composition of which is shown in Table 1.

[0091] The preparation method of this nickel-based wrought superalloy includes the following steps:

[0092] Step 1): The raw materials are subjected to vacuum induction furnace melting, protective atmosphere electroslag remelting, and vacuum consumable remelting. The smelted alloy is then cast into alloy ingots.

[0093] Step 2): The alloy ingot is subjected to homogenization diffusion annealing to obtain a diffusion-annealed ingot. The γ′ phase volume fraction in the diffusion-annealed ingot is 50%, and the shape is an irregular block with a size of 300-800 nm.

[0094] The alloy ingot is first heated to 1170°C at a heating rate of 5°C / min and held for 10 hours. Then, it is heated to 1180°C at a rate of 10°C / min and held for 36 hours. Finally, it is cooled to room temperature in the furnace.

[0095] Step 3): The diffusion-annealed ingot is heated to 1100℃ at a heating rate of 5℃ / min and held at this temperature for 24h to perform γ′ phase spheroidization coarsening heat treatment, resulting in a heat-treated ingot. The volume fraction of the γ′ phase in the heat-treated ingot is 50%, and the shape is spherical with a size of 500nm~2μm.

[0096] Step 4): The heat-treated ingot is subjected to single-pass forging, with a deformation of 50%. The alloy ingot shows no obvious cracking, and an alloy with a grain size of grade eight or higher is produced. The temperature at which the γ′ phase of the alloy completely dissolves is T. m The temperature is 1150℃.

[0097] The metallographic morphology (macrostructure of the alloy - grain size) of the nickel-based wrought superalloy obtained in this embodiment is as follows: Figure 1 As shown; the SEM microstructure (γ′ phase morphology and size) of the nickel-based wrought superalloy obtained in this embodiment is as follows. Figure 2 Show. From Figure 1 and Figure 2 It can be seen that the alloy grain size is small and the γ′ phase size is relatively large. In the microstructure of the high-temperature alloy of this embodiment, the volume fraction of the γ′ phase is 50%; the γ′ phase with a size of 50-500 nm is distributed within the grains, along with irregularly shaped micron-sized MC carbides; and discontinuous chain-like nano-sized MC carbides are distributed at the grain boundaries. 23 C6 carbides and γ′ phase with a size of 500 nm to 2 μm, with the volume fraction of γ′ phase at the grain boundaries being 23%.

[0098] The alloy was subjected to performance tests, and the test results are shown in Table 2. The alloy has high strength in the service temperature range and low deformation resistance at a hot working temperature of 1100℃, which is beneficial for processing and manufacturing.

[0099] Comparative Example 1

[0100] Comparative Example 1 designs a nickel-based wrought superalloy, wherein the composition of the nickel-based wrought superalloy is shown in Table 1.

[0101] The preparation method of this nickel-based wrought superalloy includes the following steps:

[0102] Step 1): The raw materials are subjected to vacuum induction furnace melting, protective atmosphere electroslag remelting, and vacuum consumable remelting. The smelted alloy is then cast into alloy ingots.

[0103] Step 2): The alloy ingot is subjected to homogenization diffusion annealing to obtain a diffusion-annealed ingot. The volume fraction of the γ′ phase in the diffusion-annealed ingot is 48%, and the shape is an irregular block with a size of 300-800 nm.

[0104] The alloy ingot is first heated to 1160°C at a heating rate of 5°C / min and held for 10 hours. Then, it is heated to 1180°C at a rate of 10°C / min and held for 36 hours. Finally, it is cooled to room temperature in the furnace.

[0105] Step 3): The diffusion-annealed ingot is heated to 1100℃ at a heating rate of 5℃ / min and held at this temperature for 24 hours to obtain the heat-treated ingot. Here, since no Hf element is added to the alloy, the γ′ phase is not coarsened and has a size of 300-800nm.

[0106] Step 4): The heat-treated ingot is subjected to a single-pass forging process, with a deformation rate of 50%, resulting in severe cracking of the alloy ingot. The temperature T at which the alloy γ′ phase completely dissolves is... m It is 1140℃.

[0107] The metallographic morphology (macrostructure of the alloy - grain size) of the nickel-based wrought superalloy obtained in Comparative Example 1 is as follows: Figure 3 As shown; the SEM microstructure (γ′ phase morphology and size) of the nickel-based wrought superalloy obtained in Comparative Example 1 is shown below. Figure 4 Show. From Figure 3 and Figure 4 It can be seen that the alloy grains are large and the γ′ phase is small.

[0108] The alloy was subjected to performance tests, and the test results are shown in Table 2. The alloy has high strength in the service temperature range, but its deformation resistance is extremely high at the hot working temperature of 1100℃, which brings great challenges to the hot working of the alloy.

[0109] Example 2

[0110] This embodiment designs a nickel-based wrought superalloy, the composition of which is shown in Table 1.

[0111] The preparation method of this nickel-based wrought superalloy includes the following steps:

[0112] Step 1): The raw materials are subjected to vacuum induction furnace melting, protective atmosphere electroslag remelting, and vacuum consumable remelting. The smelted alloy is then cast into alloy ingots.

[0113] Step 2): The alloy ingot is subjected to homogenization diffusion annealing to obtain a diffusion-annealed ingot. The volume fraction of the γ′ phase in the diffusion-annealed ingot is 48%, and the shape is an irregular block with a size of 300-800 nm.

[0114] The alloy ingot was heated to 1170°C at a heating rate of 5°C / min and held for 10 hours. Then, it was heated to 1190°C at a rate of 10°C / min and held for 36 hours. Finally, it was cooled to room temperature with the furnace.

[0115] Step 3): Heat to 1100℃ at a heating rate of 5℃ / min and hold at this temperature for 24h to obtain the heat-treated ingot. The volume fraction of the γ′ phase in the heat-treated ingot is 48%, and the shape is spherical with a size of 500nm-2μm.

[0116] Step 4): The heat-treated ingot is subjected to single-pass forging, with a deformation of 50%. The alloy ingot shows no obvious cracks, and an alloy with a grain size of grade eight or higher is produced. The temperature at which the alloy γ′ phase completely dissolves is T. m It is 1148℃.

[0117] The alloy was subjected to performance tests, and the test results are shown in Table 2. The alloy has high strength in the service temperature range and low deformation resistance at a hot working temperature of 1100℃, which is beneficial for processing and manufacturing.

[0118] In addition, in the microstructure of the nickel-based deformed superalloy prepared in Example 2, there are γ′ phases with a size of 50-500 nm distributed within the grains and micron-sized MC carbides in irregular blocky form; discontinuous chain-like nano-sized M carbides are distributed at the grain boundaries. 23 C6 carbides and γ′ phases with sizes ranging from 500 nm to 2 μm.

[0119] Comparative Example 2

[0120] Comparative Example 2: A nickel-based wrought superalloy was designed, wherein the composition of the nickel-based wrought superalloy is shown in Table 1.

[0121] The preparation method of this nickel-based wrought superalloy includes the following steps:

[0122] Step 1): The raw materials are subjected to vacuum induction furnace melting, protective atmosphere electroslag remelting, and vacuum consumable remelting. The smelted alloy is then cast into alloy ingots.

[0123] Step 2): The alloy ingot is subjected to homogenization diffusion annealing to obtain a diffusion-annealed ingot. The volume fraction of the γ′ phase in the diffusion-annealed ingot is 20%, and the shape is an irregular block with a size of 300-800 nm.

[0124] The alloy ingot is first heated to 1050℃ at a heating rate of 5℃ / min and held for 10h. Then it is heated to 1070℃ at a rate of 10℃ / min and held for 36h. Finally, it is cooled to room temperature with the furnace.

[0125] Step 3): The temperature is increased to 980℃ at a heating rate of 5℃ / min, and held at this temperature for 24 hours to obtain the heat-treated ingot. The heat-treated ingot contains a γ′ phase with a volume fraction of 20%, a spherical shape, and a size of 500nm-1.5μm.

[0126] Step 4): Perform single-pass forging on the heat-treated ingot, where the deformation is 50% and the temperature T is when the alloy γ′ phase completely dissolves. m The temperature is 1000℃.

[0127] The alloy was subjected to performance tests, and the test results are shown in Table 2. Due to the low sum of Al, Ti and Nb content and low volume fraction of γ′ phase, the alloy has low strength and cannot meet the service requirements.

[0128] Example 3

[0129] This embodiment designs a nickel-based wrought superalloy, the composition of which is shown in Table 1.

[0130] The preparation method of this nickel-based wrought superalloy includes the following steps:

[0131] Step 1): The raw materials are subjected to vacuum induction furnace melting, protective atmosphere electroslag remelting, and vacuum consumable remelting. The smelted alloy is then cast into alloy ingots.

[0132] Step 2): The alloy ingot is subjected to homogenization diffusion annealing to obtain a diffusion-annealed ingot. The volume fraction of the γ′ phase in the diffusion-annealed ingot is 48%, and the shape is an irregular block with a size of 300-800 nm.

[0133] The alloy ingot is first heated to 1170°C at a heating rate of 5°C / min and held for 10 hours. Then, it is heated to 1180°C at a rate of 10°C / min and held for 36 hours. Finally, it is cooled to room temperature in the furnace.

[0134] Step 3): The temperature is increased to 1100℃ at a heating rate of 5℃ / min, and held at this temperature for 24 hours to obtain the heat-treated ingot. The volume fraction of the γ′ phase in the heat-treated ingot is 48%, and the shape is spherical with a size of 500nm-2μm.

[0135] Step 4): The heat-treated ingot is subjected to single-pass forging, with a deformation of 50%. The alloy ingot shows no obvious cracks, and an alloy with a grain size of grade eight or higher is produced. The temperature at which the alloy γ′ phase completely dissolves is T. m It is 1152℃.

[0136] The alloy was subjected to performance tests, and the test results are shown in Table 2. The alloy has high strength in the service temperature range and low deformation resistance at a hot working temperature of 1100℃, which is beneficial for processing and manufacturing.

[0137] In addition, in the microstructure of the nickel-based deformed superalloy prepared in Example 3, γ′ phases with a size of 50–500 nm and micron-sized MC carbides in irregular blocky form are distributed within the grains; discontinuous chain-like nano-sized M carbides are distributed at the grain boundaries. 23 C6 carbides and γ′ phases with sizes ranging from 500 nm to 2 μm.

[0138] Comparative Example 3

[0139] This embodiment designs a nickel-based wrought superalloy, the composition of which is shown in Table 1.

[0140] The preparation method of this nickel-based wrought superalloy includes the following steps:

[0141] Step 1): The raw materials are subjected to vacuum induction furnace melting, protective atmosphere electroslag remelting, and vacuum consumable remelting. The smelted alloy is then cast into alloy ingots.

[0142] Step 2): The alloy ingot is subjected to homogenization diffusion annealing to obtain a diffusion-annealed ingot. The volume fraction of the γ′ phase in the diffusion-annealed ingot is 40%, and the shape is an irregular block with a size of 300-800 nm.

[0143] The alloy ingot is first heated to 1080℃ at a heating rate of 5℃ / min and held for 10h, then heated to 1100℃ at a rate of 10℃ / min and held for 36h, and then cooled to room temperature with the furnace.

[0144] Step 3): The temperature is increased to 1020℃ at a heating rate of 5℃ / min, and held at this temperature for 24 hours to obtain the heat-treated ingot. The volume fraction of the γ′ phase in the heat-treated ingot is 40%, and the shape is cubic with a size of 300nm-1μm.

[0145] Step 4): The heat-treated ingot is subjected to single-pass forging, with a deformation of 50%. Due to the high Ti / Al ratio in the alloy, the alloy is prone to work hardening, resulting in reduced plasticity, high deformation resistance, and severe ingot cracking. The temperature T at which the γ′ phase in the alloy completely dissolves is... m It is 1050℃.

[0146] The alloy was subjected to performance tests, and the test results are shown in Table 2. In addition to having high strength in the service temperature range, the alloy has extremely high deformation resistance at a hot working temperature of 1100℃, which is not conducive to processing and manufacturing.

[0147] Comparative Example 4

[0148] This embodiment designs a nickel-based wrought superalloy, the composition of which is shown in Table 1.

[0149] The preparation method of this nickel-based wrought superalloy includes the following steps:

[0150] Step 1): The raw materials are subjected to vacuum induction furnace melting, protective atmosphere electroslag remelting, and vacuum consumable remelting. The smelted alloy is then cast into alloy ingots.

[0151] Step 2): The alloy ingot is subjected to homogenization diffusion annealing to obtain a diffusion-annealed ingot. The γ′ phase volume fraction in the diffusion-annealed ingot is 50%, and the shape is an irregular block with a size of 300-800 nm.

[0152] The alloy ingot is first heated to 1150°C at a heating rate of 5°C / min and held for 10 hours. Then, it is heated to 1170°C at a rate of 10°C / min and held for 36 hours. Finally, it is cooled to room temperature in the furnace.

[0153] Step 3): The diffusion-annealed ingot is subjected to single-pass forging, with a deformation rate of 50%. Due to the lack of proper heat treatment, the alloy exhibits high deformation resistance, resulting in severe cracking of the alloy ingot. The prepared alloy ingot has coarse grain size, and the temperature T for complete dissolution of the γ′ phase is reached. m The temperature is 1145℃.

[0154] The alloy was subjected to performance tests, and the test results are shown in Table 2. In addition to having high strength in the service temperature range, the alloy has high deformation resistance at a hot working temperature of 1100℃, which is not conducive to processing and manufacturing.

[0155] The properties of the nickel-based wrought superalloys prepared in Examples 1-3 and Comparative Examples 1-4 are shown in Table 2.

[0156] Table 2

[0157]

[0158] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A nickel-based wrought superalloy, characterized in that, The chemical composition of the nickel-based wrought superalloy, by weight percentage, includes: C: 0.01–1 wt%; Al: 1–8 wt%; Co: 5–25 wt%; W: 1–5 wt%; Cr: 8–18 wt%; Mo: 1–8 wt%; Nb: 1–5 wt%; Ti: 1–3 wt%; V: 0.1–1 wt%; Hf: 0.1–2 wt%; balance Ni; In the nickel-based wrought superalloy, the sum of the weight percentages of Al, Ti, and Nb is ≥7 wt%. In the nickel-based wrought superalloy, the weight percentage ratio of Ti to Al is 0.2 to 1. The nickel-based wrought superalloy is prepared by a method comprising the following steps: Step 1) The raw materials are subjected to vacuum induction furnace melting, electroslag remelting, and vacuum consumable remelting, and then cast into alloy ingots. Step 2) The alloy ingot is subjected to homogenization diffusion annealing and cooled to room temperature to obtain the diffusion annealed ingot. Step 3) The ingot after diffusion annealing, which has been cooled to room temperature, is reheated for heat treatment to spheroidize and coarsen the γ′ phase, so as to obtain the heat-treated ingot. The heating rate of the ingot after diffusion annealing to the heat treatment temperature is 5–15 °C / min, and the heat treatment temperature is T. m - (20~70℃), and held at the heat treatment temperature for 8~72h to allow the γ′ phase to spheroidize and coarsen; T m The temperature at which the γ′ phase of a nickel-based wrought superalloy completely dissolves; In the heat-treated ingot, the γ′ phase has a size of 50 nm to 2 μm, a spherical shape, and a volume fraction of 20% to 50%. Step 4) The heat-treated ingot is subjected to a rough forging process. The ingot does not crack, and a nickel-based wrought high-temperature alloy is obtained. The carbides in the nickel-based wrought superalloy include M 23 C6 carbides and MC carbides; among which, M 23 C6 carbides are discontinuous chains with nanometer-sized dimensions, distributed at grain boundaries; MC are irregular blocks with micrometer-sized dimensions, distributed within grains; the grain size of the nickel-based wrought superalloy is higher than grade 8; the volume fraction of the γ′ phase in the nickel-based wrought superalloy is 20-50%, the size of the γ′ phase at grain boundaries is 500 nm-2 μm, and the size of the γ′ phase within the grains is 50-500 nm.

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: 0.01–0.2 wt%; Al: 1–7.6 wt%; Co: 5–23 wt%; W: 1–5 wt%; Cr: 8–18 wt%; Mo: 1–8 wt%; Nb: 1–5 wt%; Ti: 1–3 wt%; V: 0.1–1 wt%; Hf: 0.1–1.5 wt%; balance Ni.

3. The nickel-based wrought superalloy according to any one of claims 1-2, characterized in that, The volume fraction of the γ′ phase at the grain boundaries is 20–50%.

4. The method for preparing the nickel-based wrought superalloy according to any one of claims 1-3, characterized in that, The preparation method of the nickel-based wrought superalloy includes the following steps: Step 1) The raw materials are subjected to vacuum induction furnace melting, electroslag remelting, and vacuum consumable remelting, and then cast into alloy ingots. Step 2) The alloy ingot is subjected to homogenization diffusion annealing and cooled to room temperature to obtain the diffusion annealed ingot. Step 3) The ingot after diffusion annealing, which has been cooled to room temperature, is reheated for heat treatment to spheroidize and coarsen the γ′ phase, so as to obtain the heat-treated ingot. The heating rate of the ingot after diffusion annealing to the heat treatment temperature is 5–15 °C / min, and the heat treatment temperature is T. m - (20~70℃), and held at the heat treatment temperature for 8~72h to allow the γ′ phase to spheroidize and coarsen; T m The temperature at which the γ′ phase of a nickel-based wrought superalloy completely dissolves; In the heat-treated ingot, the γ′ phase has a size of 50 nm to 2 μm, a spherical shape, and a volume fraction of 20% to 50%. Step 4) The heat-treated ingot is subjected to a rough forging process to obtain a nickel-based wrought high-temperature alloy; The carbides in the nickel-based wrought superalloy include M 23 C6 carbides and MC carbides; among which, M 23 C6 carbides are discontinuous chains with nanometer-sized dimensions, distributed at grain boundaries; MC are irregular blocks with micrometer-sized dimensions, distributed within grains; the grain size of the nickel-based wrought superalloy is higher than grade 8; the volume fraction of the γ′ phase in the nickel-based wrought superalloy is 20-50%, the size of the γ′ phase at grain boundaries is 500 nm-2 μm, and the size of the γ′ phase within the grains is 50-500 nm.

5. The method for preparing the nickel-based wrought superalloy according to claim 4, characterized in that, The vacuum induction furnace smelting process includes sequentially performing full melting, refining, and tapping processes on the raw materials to obtain molten steel.

6. The method for preparing the nickel-based wrought superalloy according to claim 5, characterized in that, The temperature range for full melting treatment is 1480~1580℃, and the vacuum degree is 0~35Pa; the temperature range for refining treatment is 1480~1580℃, and the vacuum degree is ≤8Pa; the temperature range for tapping treatment is 1400~1450℃.

7. The method for preparing the nickel-based wrought superalloy according to claim 4, characterized in that, The chemical composition of the electroslag used in the electroslag remelting process, by weight percentage, includes: CaF2: 35-45%; Al2O3: 15-30%; CaO: 10-25%; MgO: 0-5%; TiO2: balance; During the electroslag remelting process: the argon flow rate is 50-100 L / min; the slag resistance sway setting range is 0.1-0.6 mohm; the melting rate control range is 2.5-9.0 kg / min; and the water temperature control range is 30-60℃.

8. The method for preparing the nickel-based wrought superalloy according to claim 4, characterized in that, The control parameters for the vacuum arc remelting process are set as follows: melting rate control range is 2.5~4kg / min; helium pressure control range is 300~650Pa; vacuum degree during the smelting stabilization stage is ≤1.5Pa; cooling water temperature control range is 15~30℃.

9. The method for preparing the nickel-based wrought superalloy according to claim 4, characterized in that, In step 2): The alloy ingot is heated to T1 and held at T1 for a first set time; then, it is heated to T2 and held at T2 for a second time; finally, it is cooled to room temperature to obtain the ingot after diffusion annealing. Where T1 is T m + (5~50℃); T2 is T m + (20~70℃); The initial time setting is 5 to 20 hours; The second time setting is 10 to 45 hours.

10. The method for preparing the nickel-based wrought superalloy according to claim 9, characterized in that, The heating rate of the alloy ingot to T1 is 5–15 °C / min; the heating rate from T1 to T2 is 5–25 °C / min.

11. The method for preparing the nickel-based wrought superalloy according to claim 4, characterized in that, In the ingot after diffusion annealing, the volume fraction of the γ′ phase is not less than 20%.

12. The method for preparing the nickel-based wrought superalloy according to claim 4, characterized in that, In step 3): In the ingot after diffusion annealing, the γ′ phase has a size of 50 nm to 800 nm and an irregular cubic shape.

13. The method for preparing the nickel-based wrought superalloy according to claim 4, characterized in that, In step 4): The forging process is a single-pass forging process.

14. The method for preparing a nickel-based wrought superalloy according to claim 13, characterized in that, In single-pass forging, the deformation temperature is 1050–1140℃, the holding time is 1–2 h, and the strain rate is 0.5–0.05 / s. When the deformation is 30–60%, the ingot does not crack.

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