A method for producing a nickel-based wrought superalloy

Abstract

The application relates to a preparation method of a nickel-based wrought superalloy and belongs to the technical field of nickel-based wrought superalloy preparation, which solves the problems of difficult control of the purity of the existing nickel-based wrought superalloy, serious segregation of strengthening elements and coarse dendritic structure. The preparation method comprises the following steps: preparation and subpackaging of raw materials, raw material melting, primary refining, first-time Y raw material adding and impurity removing, secondary refining, second-time feeding and pouring and solidification out of the furnace. The nickel-based wrought superalloy prepared by the method has good performance.

Description

Technical Field

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

[0002] Nickel-based wrought superalloys are widely used in hot-end components such as aero-engines and gas turbines due to their excellent high-temperature strength, creep properties, fatigue properties, and oxidation resistance. With the increasing demands on engine performance, higher requirements are being placed on the heat resistance and microstructure uniformity of these superalloys.

[0003] In existing technologies, to improve the performance of nickel-based wrought superalloys, the types and contents of strengthening elements (such as W, Mo, Ti, Nb, etc.) in the alloy are usually increased. However, this often leads to problems such as difficulty in controlling alloy purity, increased element segregation, and coarse dendrite structure, which seriously affect the metallurgical quality and subsequent processing performance of the alloy. Especially under high alloying conditions, the alloy solidification process is complex and prone to the formation of coarse dendrites and harmful phases, reducing the overall performance of the alloy.

[0004] Therefore, it is of great significance to develop a method for preparing high-temperature alloys that can effectively control alloy purity, suppress element segregation, and refine dendritic structures. Summary of the Invention

[0005] In view of the above analysis, the present invention aims to provide a method for preparing nickel-based wrought superalloys, in order to solve one of the problems that existing methods for preparing nickel-based wrought superalloys easily lead to difficulty in controlling alloy purity, aggravated element segregation, coarse dendrite structure, and poor overall alloy performance.

[0006] The objective of this invention is mainly achieved through the following technical solutions: This invention provides a method for preparing a nickel-based wrought superalloy, comprising the following steps: S1: Raw material preparation and packaging: Weigh the raw materials according to the composition ratio of the target nickel-based high-temperature alloy. After wrapping the planned rare earth element Y raw material with Ni foil, evenly distribute it into two independent feeding bins of the vacuum induction furnace. Load the remaining alloy element raw materials into the crucible of the vacuum induction furnace, seal the vacuum induction furnace and perform vacuum treatment. S2: Raw material melting: The raw materials in the crucible are heated under vacuum until they are completely melted into a homogeneous alloy liquid; S3: First refining, the first refining of the alloy liquid under specified vacuum and temperature; S4: After the first addition of Y raw material and impurity removal, and after completing one refining, the alloy liquid is cooled to the first preset temperature range. Argon gas is introduced into the vacuum induction furnace to control the vacuum degree in the furnace within the specified range. Then, rare earth Y raw material wrapped in Ni foil in a feeding bin in the vacuum induction furnace is added to the alloy liquid and the crucible is shaken to perform heat preservation and impurity removal treatment. S5: Secondary refining, improving the vacuum level and temperature in the vacuum induction furnace to perform secondary refining of the alloy liquid; S6: Second feeding. After completing the second refining, the alloy liquid is cooled to the second preset temperature range. Argon gas is introduced into the vacuum induction furnace to control the vacuum degree in the furnace within the specified range. Then, rare earth Y raw material wrapped in Ni foil in another feeding chamber in the vacuum induction furnace is added to the alloy liquid and the alloy liquid is electromagnetically stirred at the holding temperature. S7: Casting, solidification, and removal from the furnace. The alloy liquid that has been kept at a constant temperature in step S6 is cast. After casting, the alloy liquid is left to stand in the furnace for a certain period of time to allow it to solidify completely before being removed from the furnace, thus obtaining the final alloy.

[0007] Further, in step S1, the rare earth element Y raw material is elemental Y and / or Ni-Y master alloy; the purity of elemental Y is ≥99.99%, and the mass fraction of Y in the Ni-Y master alloy raw material is 20%-80%.

[0008] Furthermore, in step S2, the vacuum conditions are a vacuum degree ≤ 1 Pa and a complete melting temperature of 1500℃~1580℃.

[0009] Furthermore, in step S3, the refining temperature is 1450℃~1530℃, the refining time is ≥10min, and the vacuum degree is ≤0.1Pa.

[0010] Furthermore, in step S4, the first preset temperature range is 1430~1450℃, and the vacuum degree is 50±10Pa.

[0011] Furthermore, in step S5, the refining temperature is 1450℃~1500℃, the refining time is ≥10min, and the vacuum degree is ≤1Pa.

[0012] Furthermore, in step S6, the second preset temperature range is 1430~1480℃.

[0013] Furthermore, in step S6, the vacuum degree is ≥5000Pa.

[0014] Furthermore, in step S7, the pouring temperature is 1430–1480°C, and the settling time is ≥30 min.

[0015] The present invention also provides a nickel-based wrought superalloy, prepared by the above-described preparation method. The chemical composition of the nickel-based wrought superalloy, by mass percentage, is as follows: Y: 0.005–0.15%, Co: 14.0–16.0%, Cr: 10–12%, W: 2.5–3.5%, Mo: 4.0–5.0%, Al: 3.5–4.0%, Ti: 2.5–3.1%, Nb: 3.0–3.5%, V: 0.4–0.8%, C: 0.01–0.08%, B: 0.005–0.02%, with the remainder being Ni and unavoidable impurities.

[0016] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects: 1. The preparation method provided by this invention is an independent and complete process scheme. Its preparation process of "step-by-step addition of Y, two refining processes, and segmented atmosphere control" can be applied to various nickel-based alloy systems that require the addition of active trace elements, without depending on any specific composition. This invention precisely limits and coordinates the key parameters such as vacuum degree, temperature, time, and atmosphere pressure in the preparation process, forming a systematic and repeatable process window, ensuring the stability of product quality, and making it suitable for industrial production.

[0017] 2. When the preparation method of this invention is combined with the specific composition design of the target nickel-based wrought superalloy proposed in this invention, a significant synergistic effect is produced. The preparation method provides a reliable process guarantee for the composition to realize its design potential (high purity, low segregation, fine grains), while the composition provides the optimal target for the method. Together, they ensure that the final alloy has a small secondary dendrite spacing (38-47μm), extremely low impurity element content, and excellent high-temperature mechanical properties (section reduction of area ≥7% at 1120℃).

[0018] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0019] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0020] Figure 1 The dendritic structure diagram of the alloy prepared in Example 1; Figure 2 The dendritic structure diagram of the alloy prepared in Example 2; Figure 3 Dendritic structure diagram of the alloy prepared in Comparative Example 1; Figure 4 Dendritic structure diagram of the alloy prepared in Comparative Example 2; Figure 5 Dendritic structure diagram of the alloy prepared in Comparative Example 3; Figure 6 Dendritic structure diagram of the alloy prepared in Example 1; Figure 7 Dendritic structure diagram of the alloy prepared in Example 2; Figure 8 Dendritic structure diagram of the alloy prepared in Example 3; Figure 9 Dendritic structure diagram of the alloy prepared in Example 4; Figure 10 Dendritic structure diagram of the alloy prepared in Example 5; Figure 11 The dendritic structure diagram is shown for the alloy prepared using Example 6. Detailed Implementation

[0021] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0022] This invention provides a method for preparing a nickel-based wrought superalloy, comprising the following steps: S1: Raw material preparation and packaging: Weigh the raw materials according to the composition ratio of the target nickel-based high-temperature alloy. After wrapping the planned rare earth element Y raw material with Ni foil, evenly distribute it into two independent feeding bins of the vacuum induction furnace. Load the remaining alloy element raw materials into the crucible of the vacuum induction furnace, seal the vacuum induction furnace and perform vacuum treatment. It should be noted that the rare earth element Y raw material is elemental Y and / or Ni-Y master alloy; the purity of elemental Y is ≥99.99%, and the mass fraction of Y in the Ni-Y master alloy raw material is between 20% and 80%. To reduce the introduction of impurity O, the O content in elemental Y or Ni-Y master alloy does not exceed 80 ppm. The rare earth Y raw material has a plate-like structure, with Ni foil separating the plates, and the Ni foil ultimately completely wraps the outer surface of the Y raw material. By layering the rare earth Y raw material with Ni foil, the plate-like rare earth Y raw material can be added to the alloy liquid layer by layer to contact the alloy liquid, reducing the burning loss of rare earth Y and thus improving the yield; the plate-like rare earth Y raw material can increase the contact area between the raw material and the alloy liquid, so that the rare earth Y melts uniformly in the alloy liquid, and after complete melting, it is more evenly distributed in the alloy liquid.

[0023] The raw material of element Y was wrapped with Ni foil and then placed into two separate feeding chambers of the vacuum induction furnace. The mass ratio of rare earth Y raw material in the two feeding chambers was 1:1.

[0024] Raw materials containing other elements include carbon powder or carbon blocks (C), electrolytic cobalt (Co), high-purity chromium (Cr), molybdenum bars (Mo) or nickel-molybdenum master alloy (Ni-Mo), nickel-tungsten master alloy (Ni-W), nickel-boron master alloy (Ni-B), vanadium-aluminum master alloy (V-Al), sponge titanium or titanium ingots (Ti), aluminum briquettes (Al), nickel-niobium master alloy (Ni-Nb), and electrolytic nickel or nickel beads (Ni).

[0025] The preferred material is carbon block (C), as carbon powder dissolves faster and carbon block dissolves slower, resulting in a better deoxidation effect. The preferred material is a combination of electrolytic nickel and nickel beads. Electrolytic nickel plates have a higher content of impurities such as sulfur, while nickel beads have a higher content of impurities such as oxygen. Considering factors such as cost and purity, the Ni raw material uses a combination of electrolytic nickel and nickel beads.

[0026] S2: Raw material melting: The raw materials in the crucible are heated under vacuum until they are completely melted into a homogeneous alloy liquid; Specifically, the vacuum degree is ≤1 Pa (exemplarily, the vacuum degree is 0.2 Pa, 0.3 Pa, 0.4 Pa, 0.5 Pa, 0.6 Pa, 0.7 Pa, 0.8 Pa, 0.9 Pa), and the complete melting temperature is 1500℃~1580℃ (exemplarily, the complete melting temperature is 1505℃, 1510℃, 1515℃, 1520℃, 1525℃, 1530℃, 1535℃, 1540℃, 1545℃).

[0027] By evacuating the vacuum to ≤1 Pa (i.e., high vacuum state), the partial pressure of gases such as H2O, H2, and N2 in the furnace cavity is greatly reduced. This can effectively prevent some of the highly oxidizable active elements in the raw materials from being oxidized and forming slag during the high-temperature melting stage. If these elements are oxidized in large quantities in the early stage of melting, it will not only cause inaccurate composition control and reduced yield, but the generated oxide inclusions will also seriously deteriorate the purity and fatigue performance of the alloy.

[0028] The raw materials of the target nickel-based superalloy of this invention contain a large number of high-melting-point elements (such as W, Mo, Nb, etc.), and their liquidus temperatures are usually high. Setting the upper limit of the melting temperature at 1580°C is sufficient to ensure that all alloy raw materials (including high-melting-point metals) are completely and thoroughly melted into a homogeneous liquid phase. If the melting temperature is higher than 1580°C, the excessively high temperature will significantly aggravate the volatilization loss of certain volatile elements (such as Al, Ti, Cr, etc.), resulting in inaccurate control of the alloy composition and the formation of condensates on the inner wall of the furnace, contaminating subsequent smelting. At the same time, excessively high temperatures will aggravate the chemical reaction between the melt and the crucible, causing crucible elements (such as Mg, Ca) to dissolve into the melt, introducing new impurities and reducing the purity of the alloy. If the melting temperature is lower than 1500°C, it may result in poor melt fluidity, making it impossible to achieve effective mass and heat transfer, making it difficult to remove impurities and achieve homogeneous composition.

[0029] S3: First refining, the first refining of the alloy liquid under specified vacuum and temperature; Specifically, the refining temperature is 1450℃~1530℃ (for example, the refining temperatures are 1455℃, 1460℃, 1465℃, 1470℃, 1475℃, 1480℃, 1485℃, 1490℃, 1495℃, 1500℃, 1505℃, 1510℃, 1515℃, 1520℃, and 1525℃), and the refining time is ≥10min (for example, the refining time is 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, and 50 min). The first stage of refining involves a vacuum degree ≤0.1 Pa (exemplary vacuum degrees are 0.01 Pa, 0.02 Pa, 0.03 Pa, 0.04 Pa, 0.05 Pa, 0.06 Pa, 0.07 Pa, 0.08 Pa, and 0.09 Pa) to perform high-vacuum degassing and remove as much harmful gas as possible from the molten alloy.

[0030] It should be noted that within this refining temperature range, carbon-oxygen interaction can be promoted, melt volatilization and crucible reaction can be controlled, and the good state of the melt can be maintained. A refining time of ≥10 min ensures that the gas has sufficient time to escape, allowing inclusions to float fully and ensuring uniformity of composition and temperature. The high vacuum degree (≤0.1 Pa) creates an extremely low gas partial pressure environment, providing a huge driving force for the escape of dissolved H and N in the melt, enabling them to be deeply removed. The high vacuum environment isolates the melt from air, completely eliminating the possibility of the melt absorbing gas and oxidizing from the environment during high-temperature, long-term refining, ensuring the stability of the refining effect.

[0031] S4: After the first addition of Y raw material and impurity removal, and after completing one refining, the alloy liquid is cooled to the first preset temperature range. Argon gas is introduced into the vacuum induction furnace to control the vacuum degree in the furnace within the specified range. Then, rare earth Y raw material wrapped in Ni foil in a feeding bin in the vacuum induction furnace is added to the alloy liquid and the crucible is shaken to perform heat preservation and impurity removal treatment. Specifically, after one refining step, the alloy liquid is cooled to a first preset temperature range of 1430–1450°C (exemplary values: 1432°C, 1434°C, 1435°C, 1436°C, 1438°C, 1440°C, 1442°C, 1444°C, 1445°C, 1446°C, 1448°C). After cooling, argon gas is introduced into the vacuum induction furnace to control the vacuum level inside the furnace at 50 ± 10 Pa (exemplary values: 40 Pa, 42 Pa, 44 Pa, 46 Pa, 48 Pa, 50 Pa, 52 Pa, 54 Pa, 56 Pa, 58 Pa, 60 Pa). Rare earth Y raw material wrapped in Ni foil in a feeding bin of a vacuum induction furnace is added to the alloy liquid and the crucible is shaken to make the inclusions float to the surface, thereby achieving heat preservation and impurity removal treatment. The heat preservation temperature is 1430~1450℃ (exemplary, 1432℃, 1434℃, 1435℃, 1436℃, 1438℃, 1440℃, 1442℃, 1444℃, 1445℃, 1446℃, 1448℃), and the heat preservation time is ≥5min (exemplary, 10min, 15min, 20min, 25min, 30min).

[0032] It should be noted that the vacuum degree under argon protection is 50±10 Pa. Due to the high reactivity of rare earth element Y, it is prone to burn-off. Therefore, argon gas needs to be introduced into the vacuum induction furnace for protection before adding the alloy liquid to the crucible. If the vacuum degree is too high, a large amount of rare earth Y will vaporize during the melting process in the alloy liquid and be extracted by the vacuum system, making it impossible to form inclusions with harmful elements such as O and S in the alloy liquid to achieve impurity removal. If the vacuum degree is too low, the pressure difference between the furnace cavity of the vacuum induction furnace and the alloy liquid will be small, so that the inclusions formed in the alloy liquid after the addition of rare earth Y cannot float to the surface and the impurity gas cannot be efficiently removed. In this invention, the vacuum degree under argon protection is 50±10 Pa, which can achieve less rare earth Y burn-off and better impurity removal effect.

[0033] S5: Secondary refining, improving the vacuum level and temperature in the vacuum induction furnace to perform secondary refining of the alloy liquid; Specifically, the alloy liquid is further refined by increasing the vacuum level and temperature in the vacuum induction furnace, and further degassing is carried out. The vacuum level is ≤1 Pa (exemplary, the vacuum level is 0.2 Pa, 0.3 Pa, 0.4 Pa, 0.5 Pa, 0.6 Pa, 0.7 Pa, 0.8 Pa, 0.9 Pa), the refining temperature is 1450℃~1500℃ (exemplary, the refining temperature is 1455℃, 1460℃, 1465℃, 1470℃, 1475℃, 1480℃, 1485℃, 1490℃, 1495℃), and the refining time is ≥10 min (exemplary, the refining time is 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min).

[0034] S6: Second feeding. After completing the second refining, the alloy liquid is cooled to the second preset temperature range. Argon gas is introduced into the vacuum induction furnace to control the vacuum degree in the furnace within the specified range. Then, rare earth Y raw material wrapped in Ni foil in another feeding chamber in the vacuum induction furnace is added to the alloy liquid and the alloy liquid is electromagnetically stirred at the holding temperature. Specifically, after the secondary refining, the alloy liquid is cooled to a second preset temperature range of 1430–1480℃ (exemplary values: 1435℃, 1440℃, 1445℃, 1450℃, 1455℃, 1460℃, 1465℃, 1470℃, 1475℃). After cooling, argon gas is introduced into the vacuum induction furnace, and under argon protection, the vacuum degree is ≥5000Pa (exemplary values: 5100 Pa, 5200 Pa, 5300 Pa, 5400 Pa, 5500 Pa, 5600 Pa, 5700 Pa, 5800 Pa, 5900 Pa, 6000 Pa). The extremely high furnace pressure can suppress the volatilization of Y from the alloy liquid, thereby increasing the yield of Y. Subsequently, rare earth Y raw material wrapped in Ni foil in another feeding bin of the vacuum induction furnace is added to the alloy liquid, and the alloy liquid is electromagnetically stirred at the holding temperature to make the rare earth Y evenly distributed in the alloy liquid. During this time, the holding temperature is 1430~1480℃ (exemplary, 1435℃, 1440℃, 1445℃, 1450℃, 1455℃, 1460℃, 1465℃, 1470℃, 1475℃), and the holding time is ≥5min (exemplary, 10min, 15min, 20min, 25min, 30min).

[0035] S7: Casting, solidification, and removal from the furnace. The alloy liquid that has been kept at a constant temperature in step S6 is cast. After casting, the alloy liquid is left to stand in the furnace for a certain period of time to allow it to solidify completely before being removed from the furnace, thus obtaining the final alloy.

[0036] Specifically, the pouring temperature is 1430–1480℃ (exemplary, 1435℃, 1440℃, 1445℃, 1450℃, 1455℃, 1460℃, 1465℃, 1470℃, 1475℃), and the furnace settling time is ≥30 min (exemplary, 35 min, 40 min, 45 min, 50 min, 55 min).

[0037] Within this pouring temperature range, sufficient fluidity of the melt is ensured during pouring. Below 1430℃, the melt fluidity is poor; above 1480℃, the melt in the mold dissipates heat slowly, resulting in slow solidification and potentially coarse alloy grains. Excessively high temperatures exacerbate the segregation of alloying elements. A pouring temperature of 1430–1480℃ accelerates the solidification rate and shortens element diffusion time, thereby mitigating dendrite segregation. A furnace placement time of ≥30 minutes ensures complete solidification and internal quality of the alloy. A longer furnace placement time after pouring is equivalent to furnace cooling; this slow cooling method minimizes the temperature difference between the inside and outside of the alloy, promotes even cooling, effectively reduces thermal stress, and prevents cold cracking. It also helps obtain a uniform and stable microstructure and prevents surface oxidation and contamination.

[0038] The nickel-based wrought superalloy prepared by the method of the present invention has a relatively uniform and fine microstructure, with a secondary dendrite spacing between 38-47 μm. The alloy microstructure contains a low content of harmful interdendritic precipitates and does not have metallurgical defects such as white spots or black spots, which meets the quality requirements of high-quality nickel-based superalloys.

[0039] The target nickel-based wrought superalloy prepared by the method of this invention is prepared by the above-described preparation method. Its chemical composition, by mass percentage, is as follows: Y: 0.005–0.15%, Co: 14.0–16.0%, Cr: 10–12%, W: 2.5–3.5%, Mo: 4.0–5.0%, Al: 3.5–4.0%, Ti: 2.5–3.1%, Nb: 3.0–3.5%, V: 0.4–0.8%, C: 0.01–0.08%, B: 0.005–0.02%, with the remainder being Ni and unavoidable impurities. Preferably, the mass percentage of Y+Ti+Nb+Mo+W is 13-14%; Preferably, 7% ≤ W + Mo ≤ 8%, W / Mo ≥ 0.6; Preferably, 0.2 ≤ Y / C ≤ 5.

[0040] Preferably, 1 ≤ Y / B ≤ 15.

[0041] The reasons for limiting the mass content of each component element in the above-mentioned nickel-based wrought superalloys will be explained. Hereinafter, only the percentage of mass in the composition will be used.

[0042] Y: Rare earth element Y has high reactivity and can combine with impurity elements such as O, N, and S to form inclusions that can be removed during metallurgical processes, thus purifying the alloy. Simultaneously, during alloy solidification, the large atomic radius of rare earth Y can segregate at the solid-liquid interface, hindering element diffusion, inhibiting element segregation, and promoting nucleation. Rare earth Y can segregate at grain boundaries, reducing grain boundary energy and increasing grain boundary strength. It can also enter carbides, improving their morphology and distribution, thereby enhancing the alloy's creep resistance. However, excessive Y not only expands the solidification range of the alloy, causing more severe segregation, but the high affinity of Y for O causes O adsorption reactions in the alloy melt, contaminating the alloy. Furthermore, the formation of coarse Ni-Y intermetallic compounds by Y and Ni deteriorates mechanical properties. Therefore, in this invention, the Y content is controlled at 0.005–0.15%.

[0043] Co: As the main solid solution strengthening element in nickel-based superalloys, Co dissolves into the matrix to reduce stacking fault energy, thereby effectively improving the strength of the alloy; Co can also replace the main strengthening phase γ The position of the Ni atom in the middle can not only increase the γ at intermediate temperatures The strengthening effect of the phase can also improve the hot plasticity of the alloy at high temperatures; however, the addition of excessive Co will lead to the precipitation of harmful phases, which will damage the mechanical properties of the alloy, and Co is expensive. Therefore, the Co content in this invention is controlled at 14-16.0%.

[0044] Cr: Cr (chromium) causes the alloy to form a Cr₂O₃ oxide film on its surface during high-temperature service, improving its corrosion resistance and oxidation resistance. A low Cr content results in a less dense oxide film with poor oxidation resistance; a Cr content above 10% provides good oxidation resistance. Excessive Cr content leads to increased carbides and decreased microstructural stability, forming a TCP phase and reducing mechanical properties. This invention utilizes the significant effect of rare earth element Y (Y) in enhancing oxidation resistance, combined with a lower limit for Cr content, to improve oxidation resistance and prevent TCP phase formation. Therefore, in this invention, the Cr content is controlled at 10–12%.

[0045] W: The addition of W increases the melting point, oxidation resistance, and corrosion resistance of the alloy. W is also a strong solid solution strengthening element, which is beneficial for improving the alloy's temperature resistance. However, W has a very high tendency to segregate, easily causing W to segregate into the dendrites during solidification, thus forming a large amount of harmful phases such as Laves phase and deteriorating the alloy quality. Therefore, in order to obtain a good strengthening effect and reduce W segregation, the W content in this invention is controlled at 2.5%–3.5%.

[0046] Mo: Mo mainly plays a role in solid solution strengthening in high-temperature alloys, which can improve the high-temperature strength of the alloy; however, Mo is an element that is prone to segregation, and segregation between dendrites will cause the alloy quality to deteriorate. Moreover, a high Mo content will also promote the precipitation of harmful phases during the service of the alloy. Therefore, in this invention, the Mo content is controlled at 4.0-5.0%.

[0047] Al: Al is a strengthening phase in high-temperature alloys. One of the main components, through γ Precipitation phases strengthen the alloy by hindering dislocation movement; however, the strengthening effect is not significant when the Al content is too low, while excessive Al content may cause internal oxidation of the alloy. Therefore, in this invention, the Al content is controlled at 3.5–4%.

[0048] Ti: The addition of Ti can not only increase γ Phase content, and can replace γ The position of Al atoms in the phase increases the reverse domain boundary energy, which can enhance γ. Ti enhances mechanical properties through its strengthening effect; however, it is also a segregating element, segregating into the interdendritic space during solidification and easily forming the η phase (Ni3Ti), which increases the alloy's cracking tendency. Therefore, in this invention, the Ti content is controlled at 2.5–3.1%.

[0049] Nb: Nb is also γ One of the main constituent elements of the phase, γ When Al atoms are replaced by Nb atoms in the phase, their stability is improved, thus enhancing the strengthening effect. Simultaneously, during alloy solidification, the MC carbides formed by the combination of Nb and C not only serve as heterogeneous nucleation to refine dendrites but also increase the alloy's strength. However, Nb is a segregating element; excessive Nb will widen the solidification temperature range of nickel-based superalloys, exacerbating segregation, leading to the formation of a large amount of Laves phase between dendrites, deteriorating alloy quality, and easily causing metallurgical defects. Therefore, in this invention, the Nb content is controlled at 3.0–3.5%.

[0050] V: V mainly plays a role in solid solution strengthening in high-temperature alloys. V can also combine with C to form carbide-strengthened alloys. However, when the V content exceeds 1%, it promotes the thin-film distribution of grain boundary carbides, deteriorating mechanical properties. Therefore, in this invention, the V content is controlled at 0.4–0.8%.

[0051] C: In high-temperature alloys, C not only plays a role in interstitial solid solution strengthening and grain boundary strengthening, but it can also form MC and M with elements such as Nb, Ti, W, Cr, and Mo. 23Carbides such as C6 and M6C improve mechanical properties; however, a small amount of carbon may result in insignificant strengthening effects, while excessive carbon will form large, complex-shaped carbides that become fatigue crack initiation sites, worsening fatigue performance. Therefore, in this invention, the carbon content is controlled between 0.01% and 0.08%.

[0052] B: B is a trace element. The addition of trace amounts of B can cause it to segregate at grain boundaries, increasing grain boundary bonding and significantly improving creep resistance. However, excessive B will generate coarse, brittle borides, reducing the alloy's plasticity. Therefore, in this invention, the B content is controlled between 0.005% and 0.02%.

[0053] Y+Ti+Nb+Mo+W: To fully utilize the solid solution strengthening elements Mo and W, precipitation strengthening elements Ti and Nb, and microalloying element Y in nickel-based superalloys, the content of Y+Ti+Nb+Mo+W should be relatively high. However, the simultaneous addition of multiple strengthening elements to nickel-based superalloys will significantly expand the solidification range of the alloy, causing severe element segregation, especially for easily segregated elements Y, Ti, Nb, Mo, and W. This will reduce the quality of the alloy and even lead to metallurgical defects. Therefore, considering both the strengthening effect and the alloy quality, the content of Y+Ti+Nb+Mo+W in this invention is controlled at 13-14%.

[0054] 7%≤W+Mo≤8%, W / Mo≥0.6: W and Mo are the main solid solution strengthening elements in nickel-based superalloys, and their combined addition can achieve a more significant strengthening effect. However, both W and Mo are prone to segregation. To obtain low-segregation alloys, the content of W and Mo should not be too high. Considering all factors, 7%≤W+Mo≤8% is more reasonable. W and Mo are both TCP phase forming elements, but replacing Mo with W can effectively suppress the formation of the TCP phase. Therefore, W / Mo≥0.6 needs to be controlled.

[0055] Y / C: Y has a certain affinity for C. During solidification, a small amount of Y can enter the carbides, improving their size, morphology, and distribution, thus refining the dendrites. A low Y content leads to Y mainly agglomerating at grain boundaries, unable to enter the carbides to improve their structure. An excessive Y content may cause a large amount of Y to enter the carbides, making them skeletal and larger, failing to refine the dendrites and impairing hot workability. Therefore, considering the carbide content and other factors, in this invention, 0.2 ≤ Y / C ≤ 5.

[0056] Y / B: Although both Y and B are major grain boundary strengthening elements, their atomic radii differ significantly. Y has an atomic radius of 0.1801 nm, while B has an atomic radius of 0.117 nm. The spacing between large and small atoms at grain boundaries allows for effective grain boundary strengthening. Y can not only concentrate at grain boundaries but also at crystal defects such as dislocations, stacking faults, and vacancies; therefore, the content of Y should be higher than that of B. In this invention, 1 ≤ Y / B ≤ 15.

[0057] Preferably, the present invention provides a nickel-based wrought superalloy with the following chemical composition by mass percentage: Y: 0.01-0.15%, Co: 14.81-14.91%, Cr: 10.91-11.01%, W: 3.05-3.09%, Mo: 4.41-4.63%, Al: 3.7-3.81%, Ti: 2.65-2.71%, Nb: 3.14-3.27%, V: 0.58-0.62%, C: 0.034-0.035%, B: 0.005-0.01%, with the remainder being Ni and unavoidable impurities; Preferably, the mass percentage of Y+Ti+Nb+Mo+W is 13.4% to 13.57%; Preferably, 7.46%≤W+Mo%≤7.69, 0.6≤W / Mo≤0.692; Preferably, 0.294≤Y / C≤4.412.

[0058] Preferably, 1 ≤ Y / B ≤ 15.

[0059] The preparation method provided by this invention is an independent and complete process scheme. Its preparation process of "step-by-step addition of Y, two refining processes, and segmented atmosphere control" can be applied to various nickel-based alloy systems that require the addition of active trace elements, without relying on any specific composition. This invention precisely limits and coordinates the key parameters such as vacuum degree, temperature, time, and atmosphere pressure in the preparation process, forming a systematic and repeatable process window, ensuring the stability of product quality, and making it suitable for industrial production.

[0060] When the preparation method of this invention is combined with the specific composition design of the target nickel-based wrought superalloy proposed in this invention, a significant synergistic effect is produced. The preparation method provides a reliable process guarantee for the composition to realize its design potential (high purity, low segregation, fine grains), while the composition provides the optimal target for the method. Together, they ensure that the final alloy has a small secondary dendrite spacing (38-47 μm), extremely low impurity element content, and excellent high-temperature mechanical properties (reduction of area ≥7% at 1120℃). Specifically, by adding an appropriate amount of rare earth element Y to the nickel-based wrought superalloy, and through two refining and feeding processes, the low free energy of rare earth element Y combined with impurity elements such as O and S is utilized to form high-melting-point, low-density inclusions (such as Y2O3, YS, etc.). These inclusions float to the surface in the alloy liquid and are removed. With the control of key smelting parameters (refining temperature and time, feeding, vacuum degree), efficient removal of O, S, N, and P from rare earth Y can be achieved in the metallurgical process, resulting in a high-purity alloy. By controlling easily segregating elements... By utilizing the atomic size effect and unique physicochemical properties of rare earth element Y (Y), the Y element is segregated at the solid-liquid interface to hinder the diffusion of easily segregated elements into the liquid phase during solidification, thus reducing segregation. Simultaneously, the Y segregated at the solid-liquid interface can reduce the interfacial energy, surface tension, and critical nucleation undercooling, thereby promoting grain nucleation during solidification. Combined with a suitable casting temperature, this accelerates melt solidification, inhibits segregation, and refines dendrites, achieving the preparation of fine-dendritic, low-segregation alloys and significantly improving the metallurgical quality of the obtained vacuum induction melting alloys. The two refining and feeding processes ensure both the removal of impurities from rare earth Y and the effective addition of rare earth Y, achieving micro-alloying of rare earth Y.

[0061] The nickel-based wrought superalloy prepared by this invention has a tensile strength ≥150MPa (e.g., 152-172MPa), a yield strength ≥105MPa (e.g., 108-122MPa), an elongation ≥5.0% (e.g., 5.2-7.2%), and a reduction of area ≥7% (e.g., 7.2-9.0%) at 1120℃.

[0062] Example 1 This embodiment provides a method for preparing a nickel-based wrought superalloy. The chemical composition of the target nickel-based wrought superalloy, by mass percentage, is as follows: Y: 0.05%, Co: 14.91%, Cr: 10.95%, W: 3.09%, Mo: 4.59%, Al: 3.7%, Ti: 2.66%, Nb: 3.14%, V: 0.59%, C: 0.035%, B: 0.01%, with the remainder being Ni and unavoidable impurities. The mass percentages of Y+Ti+Nb+Mo+W are 13.53%; W+Mo is 7.68%; W / Mo is 0.673; Y / C is 1.429; and Y / B is 5.

[0063] The preparation method of the nickel-based wrought superalloy in this embodiment includes the following steps: S1: Raw material preparation and packaging: Weigh the raw materials according to the composition ratio of the target nickel-based high-temperature alloy. After wrapping the planned rare earth element Y raw material with Ni foil, evenly distribute it into two independent feeding bins of the vacuum induction furnace. Load the remaining alloy element raw materials into the crucible of the vacuum induction furnace, seal the vacuum induction furnace and perform vacuum treatment. Among them, the rare earth Y element raw material is elemental Y or Ni-Y master alloy; the purity of elemental Y is ≥99.99%, the mass fraction of Y in the Ni-Y master alloy raw material is between 20% and 80%; the O content in elemental Y or Ni-Y master alloy does not exceed 80ppm.

[0064] The raw material of element Y was wrapped with Ni foil and then placed into two different feeding bins of a vacuum induction furnace. The mass ratio of rare earth Y raw material in the two feeding bins was 1:1.

[0065] Raw materials containing other elements include carbon powder or carbon blocks (C), electrolytic cobalt (Co), high-purity chromium (Cr), molybdenum bars (Mo) or nickel-molybdenum master alloy (Ni-Mo), nickel-tungsten master alloy (Ni-W), nickel-boron master alloy (Ni-B), vanadium-aluminum master alloy (V-Al), sponge titanium or titanium ingots (Ti), aluminum briquettes (Al), nickel-niobium master alloy (Ni-Nb), and electrolytic nickel or nickel beads (Ni).

[0066] S2: Raw material melting: The raw materials in the crucible are heated under vacuum until they are completely melted into a homogeneous alloy liquid; Specifically, the vacuum level is 0.1 Pa, and the complete melting temperature is 1550℃.

[0067] S3: First refining, the first refining of the alloy liquid under specified vacuum and temperature; Specifically, the refining temperature is 1530℃ and the refining time is 10 minutes. The first stage of refining is carried out under a high vacuum of 0.1 Pa to remove harmful gases from the molten alloy as much as possible.

[0068] S4: After the first addition of Y raw material and impurity removal, and after completing one refining, the alloy liquid is cooled to the first preset temperature range. Argon gas is introduced into the vacuum induction furnace to control the vacuum degree in the furnace within the specified range. Then, rare earth Y raw material wrapped in Ni foil in a feeding bin in the vacuum induction furnace is added to the alloy liquid and the crucible is shaken to perform heat preservation and impurity removal treatment. After one refining process, the alloy liquid is cooled to the first preset temperature of 1450℃. After cooling, argon gas is introduced into the vacuum induction furnace. Under the protection of argon gas, the vacuum degree is 50Pa. Rare earth Y raw material wrapped in Ni foil in a feeding bin of the vacuum induction furnace is added to the alloy liquid and the crucible is shaken to make the inclusions float to the surface, thereby achieving heat preservation and impurity removal treatment. The heat preservation temperature is 1450℃ and the heat preservation time is 5min.

[0069] S5: Secondary refining, improving the vacuum level and temperature in the vacuum induction furnace to perform secondary refining of the alloy liquid; The process involves increasing the vacuum level and temperature in the vacuum induction furnace to perform secondary refining of the alloy liquid and further degassing. The vacuum level is 1 Pa, the refining temperature is 1500℃, and the refining time is 10 min.

[0070] S6: Second feeding. After completing the second refining, the alloy liquid is cooled to the second pre-review temperature range. Argon gas is introduced into the vacuum induction furnace to control the vacuum degree in the furnace within the specified range. Then, rare earth Y raw material wrapped in Ni foil in another feeding chamber in the vacuum induction furnace is added to the alloy liquid and the alloy liquid is electromagnetically stirred at the holding temperature. After the secondary refining, the alloy liquid is cooled to the second preset temperature of 1460℃. After cooling, argon gas is introduced into the vacuum induction furnace, and the vacuum degree is 5000Pa under argon protection. Then, rare earth Y raw material wrapped in Ni foil in another feeding chamber of the vacuum induction furnace is added to the alloy liquid, and the alloy liquid is electromagnetically stirred at the holding temperature to make the rare earth Y evenly distributed in the alloy liquid. During this time, the holding temperature is 1460℃ and the holding time is 5min.

[0071] S7: Casting and unloading: The alloy liquid that has been kept at a constant temperature in step S6 is cast. After casting, it is placed in the furnace for a certain period of time to allow the alloy liquid to completely solidify before being unloaded, thus obtaining the final alloy.

[0072] Specifically, the pouring temperature is 1460℃, and the placement time in the furnace is 30 minutes.

[0073] Example 2 This embodiment provides a method for preparing a nickel-based wrought superalloy, the chemical composition of which is the same as that in Example 1.

[0074] The preparation method is similar to that in Example 1, except that: In S3, the refining temperature is 1500℃ and the refining time is 15min; In S5, the refining temperature is 1480℃ and the refining time is 15min; In S6, the cooling temperature is 1450℃, the vacuum degree is 6000Pa, the holding temperature is 1450℃, and the holding time is 7min.

[0075] In S7, the pouring temperature is 1450℃.

[0076] Comparative Example 1 This comparative example provides a method for preparing a nickel-based wrought superalloy. The chemical composition of the target nickel-based wrought superalloy, by mass percentage, is as follows: Co: 14.96%, Cr: 10.97%, W: 3.06%, Mo: 4.57%, Al: 3.75%, Ti: 2.68%, Nb: 3.14%, V: 0.6%, C: 0.035%, B: 0.01%, with the remainder being Ni and unavoidable impurities. The mass percentage of Ti+Nb+Mo+W is 13.45%; W+Mo is 7.63%; and the W / Mo ratio is 0.669.

[0077] The preparation method of a nickel-based wrought superalloy in this comparative example includes the following steps: S1: Preparation of raw materials for smelting: Weigh the corresponding raw materials of Ni, Co, Cr, W, Mo, Al, Ti, Nb, V, C and B elements according to the element ratio principle of the nickel-based wrought high-temperature alloy, put the raw materials of the elements into the crucible of the vacuum induction furnace, seal the vacuum induction furnace and perform vacuum treatment.

[0078] S2: Raw material melting: The raw materials in the crucible are heated under vacuum conditions to completely melt them into a liquid. The vacuum level is 0.1 Pa, and the complete melting temperature is 1550 °C.

[0079] S3: Refining: Refining the molten alloy in the crucible after the raw materials have been completely melted; The refining temperature is 1530℃, the refining time is 15min, and the vacuum degree is 0.1Pa to carry out high vacuum degassing to remove as much harmful gas as possible from the alloy liquid.

[0080] S4: Casting and unloading: The refined alloy liquid is cast, and after casting, it is placed in the furnace for a certain period of time to allow the alloy liquid to completely solidify before being unloaded to finally obtain the alloy. The pouring temperature range is 1460℃, and the furnace placement time is 30 minutes.

[0081] Comparative Example 2 This comparative example provides a method for preparing a nickel-based wrought superalloy, the chemical composition of which is the same as that of Example 1.

[0082] The preparation method is similar to that in Example 1, except that: In step S4, the vacuum level is 500 Pa under argon protection. In step S6, the vacuum level is 3000 Pa under argon protection.

[0083] Comparative Example 3 This comparative example provides a method for preparing a nickel-based wrought superalloy. The chemical composition of the target nickel-based wrought superalloy, by mass percentage, is as follows: Y: 0.07%, Co: 14.85%, Cr: 10.92%, W: 3.06%, Mo: 4.63%, Al: 3.75%, Ti: 2.65%, Nb: 3.16%, V: 0.58%, C: 0.034%, B: 0.01%, with the remainder being Ni and unavoidable impurities. The mass percentages of Y+Ti+Nb+Mo+W are 13.57%; W+Mo is 7.69%; W / Mo is 0.661; Y / C is 2.059; and Y / B is 7.

[0084] The preparation method of this comparative example of a nickel-based wrought superalloy is similar to that of Example 1, except that it uses a single refining process and a single addition of Y raw materials, specifically: S3: Refining, which involves refining the molten alloy after the raw materials in the crucible have been completely melted; Specifically, the refining temperature is 1530℃, and the refining time is 15 minutes. The vacuum degree is 0.1 Pa, and high-vacuum degassing is performed to remove as many harmful gases as possible from the alloy liquid.

[0085] S4: After the refining is completed, the alloy liquid is cooled down. After cooling down, argon gas is introduced into the vacuum induction furnace. Then, the rare earth Y raw material wrapped in Ni foil in the feeding chamber of the vacuum induction furnace is added to the alloy liquid and the crucible is shaken to carry out heat preservation and impurity removal treatment. After refining, the alloy liquid is cooled to 1490℃. After cooling, argon gas is introduced into the vacuum induction furnace. Under argon protection, the vacuum degree is 3000Pa. All the rare earth Y raw materials wrapped in Ni foil in the feeding bin of the vacuum induction furnace are added into the alloy liquid and the crucible is shaken to make the inclusions float to the surface, thus achieving heat preservation and impurity removal treatment. The heat preservation temperature is 1490℃ and the heat preservation time is 5 minutes.

[0086] S5: Casting and unloading from the furnace. The alloy liquid that has been kept at a constant temperature in step S4 is cast. After casting, it is placed in the furnace for a certain period of time to allow the alloy liquid to completely solidify before being unloaded from the furnace, thus obtaining the final alloy.

[0087] Specifically, the pouring temperature is 1490℃, and the furnace placement time is 30 minutes.

[0088] Application Example 1 This application example prepares the target nickel-based wrought superalloy using the preparation method of Example 1. The chemical composition of the prepared target nickel-based wrought superalloy, by mass percentage, is as follows: Y: 0.015%, Co: 14.91%, Cr: 11%, W: 3.05%, Mo: 4.48%, Al: 3.81%, Ti: 2.71%, Nb: 3.27%, V: 0.62%, C: 0.034%, B: 0.01%, with the remainder being Ni and unavoidable impurities. The mass percentages of Y+Ti+Nb+Mo+W are 13.53%; W+Mo is 7.53%; W / Mo is 0.681; Y / C is 0.441; and Y / B is 1.5.

[0089] Application Example 2 This application example prepares the target nickel-based wrought superalloy using the preparation method of Example 1. The chemical composition of the prepared target nickel-based wrought superalloy, by mass percentage, is as follows: Y: 0.01%, Co: 14.81%, Cr: 11.01%, W: 3.05%, Mo: 4.41%, Al: 3.81%, Ti: 2.69%, Nb: 3.24%, V: 0.62%, C: 0.034%, B: 0.01%, with the remainder being Ni and unavoidable impurities. The mass percentages of Y+Ti+Nb+Mo+W are 13.40%; W+Mo is 7.46%; W / Mo is 0.692; Y / C is 0.294; and Y / B is 1.

[0090] Application Example 3 This application example prepares the target nickel-based wrought superalloy using the preparation method of Example 1. The chemical composition of the prepared target nickel-based wrought superalloy, by mass percentage, is as follows: Y: 0.07%, Co: 14.85%, Cr: 10.92%, W: 3.06%, Mo: 4.63%, Al: 3.75%, Ti: 2.65%, Nb: 3.16%, V: 0.58%, C: 0.034%, B: 0.01%, with the remainder being Ni and unavoidable impurities. The mass percentages of Y+Ti+Nb+Mo+W are 13.57%; W+Mo is 7.69%; W / Mo is 0.661; Y / C is 2.059; and Y / B is 7.

[0091] Application Example 4 This application example prepares the target nickel-based wrought superalloy using the preparation method of Example 1. The chemical composition of the prepared target nickel-based wrought superalloy, by mass percentage, is as follows: Y: 0.1%, Co: 14.9%, Cr: 10.94%, W: 3.06%, Mo: 4.57%, Al: 3.70%, Ti: 2.65%, Nb: 3.14%, V: 0.59%, C: 0.035%, B: 0.01%, with the remainder being Ni and unavoidable impurities. The mass percentages of Y+Ti+Nb+Mo+W are 13.52%; W+Mo is 7.63%; W / Mo is 0.67; Y / C is 2.857; and Y / B is 10.

[0092] Application Example 5 This application example prepares the target nickel-based wrought superalloy using the preparation method of Example 1. The chemical composition of the prepared target nickel-based wrought superalloy, by mass percentage, is as follows: Y: 0.15%, Co: 14.91%, Cr: 10.91%, W: 3.07%, Mo: 4.59%, Al: 3.72%, Ti: 2.67%, Nb: 3.15%, V: 0.6%, C: 0.034%, B: 0.01%, with the remainder being Ni and unavoidable impurities. The mass percentages of Y+Ti+Nb+Mo+W are 13.63%; W+Mo is 7.66%; W / Mo is 0.669; Y / C is 4.412; and Y / B is 15.

[0093] Application Example 6 This application example prepares the target nickel-based wrought superalloy using the preparation method of Example 1. The chemical composition of the prepared target nickel-based wrought superalloy, by mass percentage, is as follows: Y: 0.2%, Co: 14.9%, Cr: 10.94%, W: 3.07%, Mo: 4.59%, Al: 3.72%, Ti: 2.67%, Nb: 3.12%, V: 0.59%, C: 0.034%, B: 0.01%, with the remainder being Ni and unavoidable impurities. The mass percentages of Y+Ti+Nb+Mo+W are 13.65%; W+Mo is 7.66%; W / Mo is 0.669; Y / C is 5.882; and Y / B is 20.

[0094] Table 1 shows the chemical composition of the alloys in the examples, comparative examples, and application examples. Table 2 shows the test results for the impurity element content in the alloys in the examples, comparative examples, and application examples. Table 3 shows the secondary dendrite spacing and segregation coefficients of Ti, Nb, Mo, and W in the alloys in the examples, comparative examples, and application examples. Table 4 shows the tensile properties of the alloys in the examples, comparative examples, and application examples at 1120°C.

[0095] Table 1 shows the chemical composition (wt, %) of the alloys in the examples, comparative examples, and application examples.

[0096] Table 2. Test table of impurity element content in alloys of examples, comparative examples and application examples.

[0097] Table 3. Secondary dendrite spacing and segregation coefficients of some elements in the alloys of the Examples, Comparative Examples and Application Examples.

[0098] Table 4. Tensile properties at 1120°C of alloys from Examples, Comparative Examples, and Application Examples.

[0099] The O, N, S, and P impurity element contents of the alloys from vacuum induction melting in Examples 1-2, Comparative Examples 1-3, and Application Examples 1-6 were tested, and the results are shown in Table 2. Dendritic structures were observed at half the radius of the alloys from Examples 1-2, Comparative Examples 1-3, and Application Examples 1-6, and the results are shown in Table 2. Figures 1-11 As shown in Table 3, the secondary dendrite spacing and segregation coefficients of Ti, Nb, Mo, and W elements in the alloys of Examples 1-2, Comparative Examples 1-3, and Application Examples 1-6 were tested.

[0100] As shown in Tables 2-4, the target nickel-based wrought superalloy of Comparative Example 1 does not contain Y element. Its preparation method uses conventional one-time melting, refining, and casting, without performing the stepwise Y addition, secondary refining, and secondary feeding steps of this invention. Comparative Example 2 aims to prepare the same target nickel-based wrought superalloy as Example 1, but some process parameters do not meet the requirements of this invention. The target proportion of the nickel-based wrought superalloy to be prepared in Comparative Example 3 meets the requirements, but its preparation method is one-time refining and one-time feeding, which does not meet the requirements of this invention. The impurity element content in the alloys of Comparative Examples 1-3 is greater than that in Examples 1-2. The secondary dendrite spacing of the alloys of Comparative Examples 1-3 is coarser than that in Examples 1-2. The segregation coefficient of some elements in Comparative Examples 1-3 deviates more from 1 than that in Examples 1-2, indicating more severe segregation than in Examples 1-2. The tensile properties of the alloys of Comparative Examples 1-3 at 1120℃ are weaker than those of Examples 1-2.

[0101] Application Examples 1-5 show that the target nickel-based wrought superalloys prepared by the inventive method of this application exhibit good performance. Application Example 6 shows that the target nickel-based wrought superalloy contains an excessive amount of Y, resulting in weaker performance compared to Application Examples 1-5.

[0102] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a nickel-based wrought superalloy, characterized in that, Includes the following steps: S1: Raw material preparation and packaging: Weigh the raw materials according to the composition ratio of the target nickel-based high-temperature alloy. After wrapping the planned rare earth element Y raw material with Ni foil, evenly distribute it into two independent feeding bins of the vacuum induction furnace. Load the remaining alloy element raw materials into the crucible of the vacuum induction furnace, seal the vacuum induction furnace and perform vacuum treatment. S2: Raw material melting: The raw materials in the crucible are heated under vacuum until they are completely melted into a homogeneous alloy liquid; S3: First refining, the first refining of the alloy liquid under specified vacuum and temperature; S4: After the first addition of Y raw material and impurity removal, and after completing one refining, the alloy liquid is cooled to the first preset temperature range. Argon gas is introduced into the vacuum induction furnace to control the vacuum degree in the furnace within the specified range. Then, rare earth Y raw material wrapped in Ni foil in a feeding bin in the vacuum induction furnace is added to the alloy liquid and the crucible is shaken to perform heat preservation and impurity removal treatment. S5: Secondary refining, improving the vacuum level and temperature in the vacuum induction furnace to perform secondary refining of the alloy liquid; S6: Second feeding. After completing the second refining, the alloy liquid is cooled to the second preset temperature range. Argon gas is introduced into the vacuum induction furnace to control the vacuum degree in the furnace within the specified range. Then, rare earth Y raw material wrapped in Ni foil in another feeding chamber in the vacuum induction furnace is added to the alloy liquid and the alloy liquid is electromagnetically stirred at the holding temperature. S7: Casting, solidification, and removal from the furnace. The alloy liquid that has been kept at a constant temperature in step S6 is cast. After casting, the alloy liquid is left to stand in the furnace for a certain period of time to allow it to solidify completely before being removed from the furnace, thus obtaining the final alloy.

2. The preparation method according to claim 1, characterized in that, In step S1, the rare earth element Y raw material is elemental Y and / or Ni-Y master alloy; the purity of elemental Y is ≥99.99%, and the mass fraction of Y in the Ni-Y master alloy raw material is 20%-80%.

3. The preparation method according to claim 1, characterized in that, In step S2, the vacuum conditions are a vacuum degree ≤ 1 Pa and a complete melting temperature of 1500℃~1580℃.

4. The preparation method according to claim 1, characterized in that, In step S3, the refining temperature is 1450℃~1530℃, the refining time is ≥10min, and the vacuum degree is ≤0.1Pa.

5. The preparation method according to claim 1, characterized in that, In step S4, the first preset temperature range is 1430~1450℃, and the vacuum degree is 50±10Pa.

6. The preparation method according to claim 1, characterized in that, In step S5, the refining temperature is 1450℃~1500℃, the refining time is ≥10min, and the vacuum degree is ≤1Pa.

7. The preparation method according to claim 1, characterized in that, In step S6, the second preset temperature range is 1430~1480℃.

8. The preparation method according to claim 7, characterized in that, In step S6, The vacuum degree is ≥5000Pa.

9. The preparation method according to claim 1, characterized in that, In step S7, the pouring temperature is 1430~1480℃, and the standing time is ≥30min.

10. A nickel-based wrought superalloy, prepared by any one of the preparation methods of claims 1-9, characterized in that, The chemical composition of the nickel-based wrought superalloy, by mass percentage, is as follows: Y: 0.005–0.15%, Co: 14.0–16.0%, Cr: 10–12%, W: 2.5–3.5%, Mo: 4.0–5.0%, Al: 3.5–4.0%, Ti: 2.5–3.1%, Nb: 3.0–3.5%, V: 0.4–0.8%, C: 0.01–0.08%, B: 0.005–0.02%, with the remainder being Ni and unavoidable impurities.

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