High-entropy Ni-Fe-Cr-based high-temperature alloy designed based on cluster type method and preparation method and application of high-entropy Ni-Fe-Cr-based high-temperature alloy

Abstract

The invention relates to a high-entropy Ni-Fe-Cr-based high-temperature alloy designed based on a cluster type method and a preparation method and application of the high-entropy Ni-Fe-Cr-based high-temperature alloy. The alloy is designed based on a 16-atomic component formula of a cluster and connecting atom model, the components of the alloy fall within the range of Ni7-6Fe5-6 (Cr, Mo, Si, Nb and Mn) 4-5 in a Ni-Fe-Cr-like pseudo ternary diagram, a single-phase face-centered cubic structure is formed, and NbC is dispersed and separated out. The Cr-like element content is increased through high-entropy alloying, stability and high strength (the tensile strength is larger than or equal to 460 MPa) are kept at the high temperature on the premise of not depending on gamma-phase strengthening, and meanwhile excellent corrosion resistance is achieved. The alloy is low in cost, simple in process and suitable for force-bearing structural parts under the high-corrosion working condition of 600 DEG C or below, and has good industrial application prospects.

Description

Technical Field

[0001] This invention relates to the field of high-temperature alloys, and in particular to high-entropy Ni-Fe-Cr based high-temperature alloys designed based on a cluster-based method, their preparation methods, and applications. Background Technology

[0002] High-temperature alloys are a class of metallic materials capable of maintaining excellent performance over long periods in extreme high-temperature, high-stress, and corrosive environments. Their emergence and development are inseparable from the advancements in modern industrial technology. Since the beginning of the 20th century, with the rapid development of aerospace, energy industries, and other high-tech fields, the demand for materials capable of stable operation at temperatures above 600°C has been increasing, leading to the development of high-temperature alloys. These alloys, with their superior high-temperature strength, oxidation resistance, corrosion resistance, and fatigue resistance, have become a crucial cornerstone supporting modern engineering technology.

[0003] Nickel-based superalloys hold a particularly important position in the field of high-temperature alloys. Compared with iron-based and cobalt-based superalloys, nickel-based superalloys possess higher high-temperature strength and structural stability, and are widely used in the manufacture of hot-end components for aero-jet engines and industrial gas turbines. More than 50% of the materials used in modern gas turbine engines are superalloys, with nickel-based superalloys accounting for approximately 40% of the engine materials. Nickel-based alloys exhibit excellent comprehensive properties at medium to high temperatures, making them suitable for prolonged operation at high temperatures. They are resistant to corrosion and abrasion, making them the most widely used alloys in high-temperature components and a class of alloys of great interest to many metallurgists.

[0004] Nickel-based superalloys are high-temperature alloys with nickel as the base material (generally containing more than 50%), exhibiting high strength and good resistance to oxidation and gas corrosion in the temperature range of 650~1000℃. They are based on Cr... 20 Ni 80 Developed from alloys, high-temperature alloys incorporate numerous strengthening elements, such as W, Mo, Ti, Al, Nb, and Co, to meet the requirements of high-temperature strength (high-temperature strength, creep resistance, and high-temperature fatigue strength) at around 1000℃ and resistance to oxidation and corrosion in gaseous media, thus ensuring their superior high-temperature performance. Besides solid solution strengthening, high-temperature alloys also rely on Al, Ti, and other elements to form intermetallic compounds γ-rays with Ni. Precipitation strengthening of phases (such as Ni3Al or Ni3Ti) and partial fine stabilization of MC and M 23 The intragranular dispersion strengthening of C6 carbides, along with the purifying and strengthening effects of B, Zr, and Re on grain boundaries, further enhances the oxidation and high-temperature corrosion resistance of the high-temperature alloy. Nickel-based high-temperature alloys possess excellent comprehensive properties and are currently widely used in aerospace, automotive, communications, and electronics industries.

[0005] Through systematic engineering research and development, the international materials community has achieved industrial applications of over 200 standardized high-temperature alloy grades. The optimization of their composition systems and innovation in manufacturing processes effectively support material requirements under extreme operating conditions. Typical applications include: turbine components for aerospace propulsion systems (operating temperatures of 800~1100℃), thermal protection structures for reusable spacecraft, internal components of next-generation nuclear reactors, and key heat transfer components for supercritical thermal power generators. Each grade achieves performance adaptation in specific temperature-stress coupling fields through differentiated alloy design, forming a full-spectrum material solution covering a temperature range of 650~1200℃.

[0006] To improve corrosion resistance, Cr and Mo need to be increased, but this can easily lead to the precipitation of harmful phases (such as σ phase) in traditional designs, impairing mechanical properties. Furthermore, those skilled in the art, concerned about microstructural stability, have no incentive to increase the Cr content to levels close to Ni and Fe. However, traditional nickel-based superalloys typically rely on complex multi-element ratios, resulting in high production costs and poor process stability; simultaneously, their strengthening mechanisms (such as precipitated phases) may damage the material's corrosion resistance. In recent years, while the multi-principal alloy design concept has shown potential for performance regulation in some systems, in the field of high-temperature corrosion-resistant materials, how to achieve composition simplification and performance synergy still lacks effective structural design guidance, a technical problem urgently needing to be solved by those skilled in the art. Implementing alloy simplification, i.e., reducing the number of element types to lower costs and simplify the preparation process, while maintaining structural stability, uniform element distribution, and satisfactory mechanical and corrosion resistance properties, is of great significance for the development of superalloys. Currently, there is still a lack of an effective composition design method, fundamentally due to the lack of physical structural models. How to optimize the design of nickel-based superalloys from the compositional source, while simultaneously considering low cost and high performance, has become a key problem to be solved. Summary of the Invention

[0007] This invention addresses the problems mentioned in the background section, such as the high cost and poor process stability of traditional nickel-based superalloys due to their reliance on complex multi-element ratios, and the difficulty in simultaneously achieving high corrosion resistance and structural stability. This invention uses a cluster-plus-connection atomic model to limit the proportions of Ni, Fe, and Cr-like (Cr, Mo, Si, Nb, Mn) atoms in the Ni-Fe-Cr based system (e.g., Ni...). 7~6 Fe 5~6 Cr 4~5 The corrosion resistance is improved by increasing the content of Cr-like elements through high-entropy alloying, while stabilizing a single FCC phase and reducing the types of alloying elements.

[0008] The first aspect of this invention protects a high-entropy Ni-Fe-Cr based superalloy designed based on a clustering method, which is composed of the following components by mass percentage: Ni: 38~46%, Fe: 30~38%, Cr: 19~28%, Mo: 0~3%, Mn: 0~1%, Si: 0~1%, Nb: 0~1%, C: 0~0.06%, with the balance being unavoidable impurities, and the content being less than 0.07%.

[0009] For the technical solution described above, a further preferred embodiment is that the alloy has a single-phase face-centered cubic structure with dispersed NbC precipitation; and it can be formed under a common solution treatment and quenching process at 1050℃, and maintains structural stability even at 600℃.

[0010] For the technical solution described above, it is further preferred that the minimum mass percentage of Mo, C, and Nb is greater than 0.

[0011] For the technical solution described above, it is further preferred that the mass percentage of Mo is 2 to 3%.

[0012] For the technical solution described above, it is further preferred that the mass percentage of C is 0 < C ≤ 0.06%; more preferably, it is 0.03~0.06%, and the corresponding mass percentage of Nb is 0.5~1%.

[0013] For the technical solution described above, a further preferred embodiment is that the mass percentage of Cr is 19-28%.

[0014] Furthermore, for the technical solution described above, when the Mo content is 2-3%, the mass percentage of Cr is 21-26%.

[0015] For the technical solution described above, a further preferred embodiment is that the alloy is designed based on a 16-atom composition formula using a cluster-connecting atom model, and its composition falls within the Ni category of the "Ni-Fe-Cr-like" pseudo-ternary composition diagram. 7~6 Fe 5~6 (Cr,Mo,Si,Nb,Mn) 4~5 Within this range, the Cr-like elements include Cr, Mo, Si, Nb, and Mn, belonging to face-centered cubic single-phase alloys. The contents of the three main components, Ni, Fe, and Cr, are close, reflecting the characteristics of high-entropy alloying.

[0016] The alloy contains a large amount of Cr, which gives it excellent corrosion resistance; it contains a large amount of inexpensive Fe, which gives it a cost advantage over nickel-based alloys; and it has excellent face-centered cubic structure stability because Ni is the most enriched element, and it still maintains a single phase (dispersed NbC precipitation) and sufficient strength (tensile strength 460 MPa) even at 600℃.

[0017] The alloy, in addition to the main alloying elements Ni-Fe-Cr, also contains anti-pitting Mo and metallurgical residues Si and Mn, and contains a certain amount of C to ensure solid solution strengthening and the dispersion precipitation of NbC strengthening phase together with Nb. The content of these elements is comparable to that in conventional stainless steel and nickel-based high-temperature alloys.

[0018] Another aspect of this invention protects the preparation method of the alloy described above, comprising the following steps: obtaining an alloy ingot by vacuum induction melting; subjecting the alloy ingot to homogenization heat treatment; subjecting the homogenized alloy to cold rolling deformation; and subjecting the cold-rolled alloy to solution treatment.

[0019] For the technical solution described above, a further preferred embodiment of the preparation method includes the following steps: (1) Weigh the raw materials according to the stated composition ratio and prepare alloy ingots by vacuum induction melting; (2) The ingot is homogenized at 1150°C and then cooled to room temperature in the furnace; cold rolling is then performed. (3) The cold-rolled alloy is solution treated at 1050°C and then cooled to obtain the final product. More preferably, the processing time of step (2) or (3) is 5-8 hours.

[0020] For the technical solution described above, it is further preferred that the total deformation of cold rolling in step (2) of the preparation method is 60%~80%, and the single-pass reduction is no more than 10%; more preferably, the total deformation is 70%.

[0021] Another aspect of this invention protects the application of the aforementioned alloy in the preparation of corrosion-resistant structural components (load-bearing structural components operating under high corrosion conditions below 600℃). The Ni-Fe-Cr based superalloy described herein possesses a tensile strength of not less than 400 MPa at 600℃ and a corrosion current density in a 3.5% NaCl solution not exceeding 1 × 10⁻⁶ MPa. -5 A·cm - ², it has extremely broad application prospects in manufacturing corrosion-resistant load-bearing components that operate below 600℃.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The present invention is characterized in that the high-entropy Ni-Fe-Cr based superalloy composition designed based on the 16-atom composition method of the cluster plus connecting atom model unexpectedly possesses the following characteristics: it does not require the introduction of γ... Under conditions of precipitation strengthening, i.e. on a single face-centered cubic solid solution matrix, the alloy can achieve high strength at 600℃. Simultaneously, through precise control of the total amount of "Cr-like" elements in the aforementioned composition formula, the alloy effectively maintains long-term structural stability while exhibiting high corrosion resistance through the solidification of a large amount of corrosion-resistant elements, thus preventing the precipitation of harmful phases such as the σ phase.

[0023] 2. This invention, through the aforementioned cluster composition formula, designates Mo as a crucial component of the Cr-like element and limits its content within a specific range. Unexpectedly, within this model framework, the Mo-containing alloy not only exhibits significantly enhanced pitting corrosion resistance, but also, through the global constraint of the Ni, Fe, and Cr-like proportions in the model, effectively suppresses the σ-phase precipitation that is typically induced by Mo addition. This resolves the traditional contradiction between high Mo content and microstructural stability, synergistically optimizing the alloy's corrosion resistance and mechanical properties.

[0024] 3. The alloy composition provided by this invention, while achieving the aforementioned high performance, unexpectedly also possesses low cost and excellent industrial feasibility. Through precise control of the Ni-Fe ratio via the cluster composition formula, the content of expensive Ni is reduced to a minimum of 38% while significantly increasing the content of inexpensive Fe to over 30%, thus achieving a significant cost advantage at the raw material level, while ensuring the stability of the face-centered cubic structure. More importantly, this composition system can achieve a uniform and stable ideal microstructure through conventional vacuum melting, thermomechanical treatment, and solution treatment processes, avoiding the dependence of traditional high-alloy materials on complex heat treatment or extreme process conditions. This gives it both high performance and enormous potential for large-scale industrial production and application.

[0025] 4. This invention represents a fundamental shift from "experience-based design" to "model-driven design," providing a new paradigm for high-performance alloy development. For the first time, this invention successfully applies a cluster-plus-connection atomic model to the compositional design of high-entropy Ni-Fe-Cr-based superalloys. This method transforms traditional R&D, which relies on expert experience and extensive trial-and-error, into a rational design based on a physical picture of atomic stacking, which is computationally achievable and predictable. This is achieved through the construction of a "Ni-Fe-Cr-like" pseudo-ternary system and Ni... 7~6 Fe 5~6 (Cr,Mo,Si,Nb,Mn) 4~5 The establishment of the composition formula ensures the rationality of the composition from the physical source, significantly shortens the research and development cycle, reduces development costs and risks, and provides a universal design tool for developing a series of new high-performance alloys.

[0026] 5. Exhibiting superior comprehensive performance compared to conventional alloys, meeting the material requirements of specific harsh environments. The comprehensive performance of this alloy in the mid-temperature range of 600℃ successfully fills the market gap between the insufficient temperature resistance of traditional stainless steel and the excessive cost of all-grade nickel-based alloys. It not only boasts excellent strength and corrosion resistance, but its single FCC phase matrix also ensures good plasticity and processing formability, facilitating subsequent component manufacturing. Ultimately, this alloy is precisely positioned for "mid-temperature (approximately 600℃) - high-corrosion (e.g., containing Cl)" environments. - The harsh operating condition of "environmental conditions - certain loads" provides an invaluable and ideal material solution for lightweight and long-life design in fields such as marine propulsion, chemical reactors, and deep-sea equipment. Attached Figure Description

[0027] Figure 1 XRD pattern of the alloy.

[0028] Figure 2 Metallographic image of the alloy.

[0029] Figure 3 SEM images of Cr4Ni7Fe5-Mo alloy, where a shows the elemental distribution; b shows the dispersed NbC precipitation.

[0030] Figure 4 Hardness-temperature curve of the alloy.

[0031] Figure 5 : Room temperature and high temperature tensile curves of the alloy.

[0032] Figure 6 Electrochemical Tafel polarization curves of the alloy. Detailed Implementation

[0033] The following embodiments will further illustrate the present invention.

[0034] Using the 16-atom composition formula, the contents of Ni, Fe, and Cr were varied, with those containing Mo and those without Mo serving as control groups. The composition of the examples is shown in Table 1.

[0035] Table 1. Ingredients of the Examples

[0036] 1. Alloy Preparation Raw materials: High-purity Ni, Fe, Cr, Mo, Mn, Si, Nb, and C powders (purity ≥ 99.9%).

[0037] Process: (1) Weigh the raw materials according to the composition in Table 1; (2) Alloy samples were prepared using an FJ21-02 non-consumable vacuum induction furnace.

[0038] (3) The sample was subjected to a vacuum box furnace of ZMF-1200C-M for 6 hours under vacuum and then slowly cooled to room temperature.

[0039] (4) The sample was subjected to cold rolling deformation treatment using a twin-roll mill. The total deformation was controlled to about 70% through multiple rolling passes, and the single-pass pressing was strictly limited to less than 10%. The surface of the sample was smoothed after each rolling pass.

[0040] (5) The cold-rolled sample was placed in a vacuum furnace again and subjected to a 6-hour solution treatment at 1050°C in a vacuum environment, followed by air cooling in the furnace.

[0041] In specific implementation, the "balance of unavoidable impurities" in the alloy composition refers to inclusion elements that may be introduced in trace amounts during the smelting of high-purity raw materials and alloy preparation, and are difficult to completely remove by conventional industrial means. Based on industrial practice and material performance considerations, the total mass percentage of unavoidable impurities in this invention should be less than 0.07%. "Impurities < 0.07%" is a standard industrial purity control and does not contradict the composition design. Generally, the impurities in this application mainly include phosphorus (P) and sulfur (S), and their contents are preferably controlled as follows: P ≤ 0.040%, S ≤ 0.030%. Strict control of impurity content helps to ensure the purity of the alloy, thereby ensuring that its high-temperature mechanical properties, corrosion resistance, and structural stability are not compromised.

[0042] The alloy microstructure characterization method involved in this application is as follows: Phase analysis was performed using an Empyrean X-ray diffractometer (PANACO, Netherlands) to compare and study the phase composition evolution of as-cast and final-state samples. Key experimental parameters were set as follows: the radiation source was a Cu target. K Alpha rays (λ = 0.15406 nm); tube voltage / current 40 kV / 40 mA; scanning angle 2θ 20°–90°; scanning speed 2° / min. Background subtraction and smoothing were performed on the diffraction patterns using MID Jade 6 analysis software, and phase identification was performed based on a database. Phase content was calculated using the Rietveld refinement method with full-spectrum fitting; a matching factor Rwp < 5% indicated reliable results.

[0043] Typical samples were cut using a wire EDM machine under continuous coolant flushing, ensuring the cut surface was perpendicular to the original surface at a 90° angle. Immediately after cutting, the samples were immersed in anhydrous ethanol for ultrasonic cleaning (15 min) to remove cutting residue. Finally, the sample surface was polished using SiC water-resistant sandpaper of grades 240#, 400#, 600#, 800#, 1000#, 1200#, 1500#, and 2000#. Each pass of polishing was performed until only scratches in one direction were visible before rotating the sample 90° to proceed to the next pass, preventing confusion between scratches from different directions and ensuring complete removal. The samples were then polished sequentially with 1.5 μm diamond polishing paste until a mirror-like, scratch-free finish was achieved. Water polishing for 4 minutes removed residue, followed by alcohol cleaning and drying. When preparing the etching solution, it should be done in a constant temperature and humidity experimental environment. Mix the chemical reagents according to the formula: 3g FeCl3 + 2ml HCl + 95ml C2H5OH, and stir thoroughly to prepare the etching solution. Due to the volatility of ethanol, immediately use a dropper to apply a small amount of the etching solution to the sample surface. After waiting 30 seconds, immediately rinse with deionized water for 15 seconds and use a drying device to quickly dry the sample surface. Observe the phases and structure of the alloy sample using a Leica DMi8 metallurgical microscope and a SUPRA 55 scanning electron microscope.

[0044] The alloy performance testing method involved in this application is: The hardness of the sample was tested using a ZD-HVZHT-10 high-temperature Vickers hardness tester with a load of 200g and a holding time of 15s. Before testing, the sample was placed in the experimental chamber, and then the chamber was purged. First, the mechanical pump was turned on to reduce the vacuum level inside the chamber, and then high-purity argon gas was introduced. This purging process was repeated three times to maintain a low oxygen content in the chamber and prevent oxidation of the sample surface during the high-temperature experiment. The temperature program was then set on the computer, with experimental temperatures of 20℃, 100℃, 200℃, 300℃, 400℃, 500℃, 600℃, 700℃, 800℃, 900℃, and 1000℃, each held for 30 minutes. The sample was fixed in the center of the test platform, ensuring a flat surface. The experimental parameters were then adjusted, and the focal length was quickly adjusted until the sample surface could be clearly observed. The current coordinates were then input into the device to ensure the lens automatically adjusted to the current position. Finally, switch to the indenter and apply pressure. After 60 seconds, once the edge of the prismatic indentation on the sample is clearly visible through the lens, use the four-point method to collect the hardness value of the current area. During measurement, each alloy sample is measured three times at the same temperature, and the average value is taken.

[0045] The C45-105EY microcomputer-controlled electronic universal testing machine was used to test the room temperature and high temperature tensile properties of alloy samples. The thickness of the room temperature tensile sample was 2 mm. Before performing room temperature tensile testing, the cut tensile sample surface was polished with 80# and 240# sandpaper to remove scratches and oxide scale, ensuring accurate tensile test results. The polished sample was placed in the testing machine and pre-tightened with clamps to prevent sample slippage from affecting the experiment. The tensile speed was set to 0.5 mm / min in the experimental parameters on the computer, and all values ​​were reset to zero before the experiment began. During the experiment, the surrounding environment was kept quiet to reduce experimental errors. The experiment was stopped immediately after the sample broke, and the current stress-engineering strain test data was saved. For high temperature tensile testing, a high temperature tensile fixture was prepared in advance. The prepared sample was fixed in the fixture and ensured that the sample was in a stress-free state. Then, three thermocouple wires were connected to the upper and lower ends of the fixture and the middle area of ​​the sample, respectively. Finally, the furnace was closed tightly, and asbestos was stuffed into the gaps of the furnace to ensure that the temperature inside the furnace remained stable within a certain range. Set the experimental temperature in advance, start the heating program, and keep the temperature for 10 minutes after all three thermocouples have reached the set temperature. After ensuring that the extensometer output is stable, start the tensile test. Immediately turn off the heating after the sample breaks, stop the experiment, save the data, and wait for the furnace to cool to room temperature before removing the sample.

[0046] The corrosion resistance of the samples was tested using a Gamry Reference 600+ electrochemical workstation. To simulate a seawater environment, the three-electrode electrochemical system was immersed in a 3.5% NaCl solution. The anode in the three-electrode electrochemical system was a copper sheet in contact with the sample, the cathode was a platinum electrode, and the reference electrode was a saturated calomel electrode. After immersing the samples in the solution for 10 minutes, the open-circuit potential was measured. Corrosion resistance testing was then performed when a stable potential was reached. The Tafel polarization test was selected, with a scan rate of 1 mV / s and a scan range of -0.5 to 1.3 V relative to the open-circuit potential, from negative to positive. The Tafel polarization curves of the samples were then obtained.

[0047] XRD and metallographic analysis showed that all the examples exhibited a face-centered cubic single phase after solution treatment, with no harmful precipitates found. This verifies the promoting effect of high-entropy design on phase stability. (See [link to relevant documentation]). Figure 1 and Figure 2 The alloy microstructures of the examples are similar. Taking the Cr4Ni7Fe5-Mo alloy as an example, the SEM-EDS results are as follows: Figure 3 As shown in a and b, except for Nb, which exhibits local segregation at grain boundaries due to carbide precipitation, the other elements (Cr, Ni, Fe, Mo) are uniformly distributed in the matrix, indicating that the 16-atom composition design effectively suppresses compositional segregation.

[0048] according to Figure 4 It can be seen that the room temperature hardness of the Ni6Fe5Cr5-Mo alloy reaches 260 HV, significantly higher than that of the nickel-based alloy NS1401 (190 ~ 210 HV, whose composition is similar to that of the alloy in the example). At 600℃, the tensile strength of the Ni6Fe5Cr5-Mo alloy still reaches 460.2 MPa, while its tensile strength at room temperature can reach 570 MPa. Although this is lower than the highest tensile strength of 602.4 MPa (Ni7Fe5Cr4-Mo), the comprehensive mechanical properties show that the alloy can maintain the stability of key mechanical properties under both room temperature and high temperature environments. Figure 5 As shown, high Cr content significantly improves hardness and high-temperature strength, while high Ni content optimizes plasticity by stabilizing the FCC phase; the two work synergistically to achieve a balance between strength and toughness. In high-temperature tensile tests, the alloys in the examples all exhibited dynamic strain aging phenomena (serrated stress-strain curves) below 600°C, see [reference needed]. Figure 5 The dissolution strength of the Ni3Nb phase drops sharply above 750°C, indicating that the applicable temperature of the alloy in the example should be controlled below 750°C.

[0049] Electrochemical tests showed that the self-corrosion potential of the high-Cr Mo alloy in 3.5% NaCl solution shifted significantly to the positive direction (Ni6Fe5Cr5-Mo). E corr = -0.06 V), corrosion current density ( I corr As low as 10 -6 A·cm 2 Furthermore, the alloys with added Mo in the examples all exhibited significant passivation zones, indicating that Cr and Mo work together to more effectively resist Cl. - Erosion, see Figure 6 .

[0050] Experiments show that the room temperature hardness of the Ni6Fe5Cr5-Mo alloy (containing Mo) reaches 260 HV, significantly higher than that of the traditional nickel-based alloy NS1401 (190 ~ 210 HV) with similar composition. Its room temperature tensile strength reaches 570 MPa, and even at 600℃, the tensile strength still reaches 460.2 MPa. Above 750℃, the strength drops sharply due to the dissolution of the Ni3Nb phase, indicating that its applicable temperature should be controlled below 750℃, and it does not require γ-ray diffusivity. Phase precipitation strengthening can maintain high-temperature strength. Electrochemical tests show that the alloy's self-corrosion potential... E corr = -0.06 V, corrosion current density I corr = 10 -6 A·cm -2This patent provides an alloy composition and corresponding preparation process that enables the production of a new high-entropy Ni-Fe-Cr type superalloy with excellent corrosion resistance. Furthermore, it allows for the addition of precipitated strengthening phases to the face-centered cubic matrix to enhance high-temperature mechanical properties, providing a material reserve for engineering applications. Compared to traditional nickel-based superalloys with Ni content >50%, this invention reduces the Ni content to a minimum of 38% while maintaining a tensile strength exceeding 460 MPa at 600°C, and reduces its corrosion current density in 3.5% NaCl solution to 10 MPa. -6 A·cm - On the order of 2, it achieves a balance between low cost and high corrosion resistance.

[0051] The above-described embodiments are merely illustrative of the implementation methods of the present invention, but should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the protection scope of the present invention.

Claims

1. A high-entropy Ni-Fe-Cr-based superalloy, characterized in that: It is composed of the following ingredients in mass percentage Ni: 38~46%, Fe: 30~38%, Cr: 19~28%, Mo: 0~3%, Mn: 0~1%, Si: 0~1%, Nb: 0~1%, C: 0~0.06%, impurities: <0.07%.

2. The alloy of claim 1 wherein: The alloy is single-phase face-centered cubic structure and dispersively precipitates NbC.

3. The alloy of claim 1 wherein, The minimum mass percentage of Mo, C and Nb is greater than 0.

4. The alloy of claim 1 wherein, The mass percentage of Cr is 19~28%.

5. The alloy of claim 1 wherein, The mass percentage of C is 0 6. The alloy of claim 1 wherein: The alloy is based on a 16-atom compositional design of cluster-plus-bonding-atom model, whose composition falls in the range of Ni 7~6 Fe 5~6 (Cr, Mo, Si, Nb, Mn) 4~5 range.

7. A method of producing the alloy as claimed in claim 1, characterized in that, The mass percentage of C is 0 The steps include:

8. The preparation method according to claim 7, characterized in that, Vacuum induction melting is used to obtain alloy ingot; the alloy ingot is subjected to homogenization heat treatment; the homogenized alloy is subjected to cold rolling deformation; and the cold-rolled alloy is subjected to solid solution treatment to obtain the alloy. The steps include: (1) raw materials are weighed according to the ingredient proportioning, and vacuum induction melting is used to prepare alloy ingot; (2) the ingot is homogenized at 1150℃, and then cooled to room temperature in the furnace; and cold rolling is performed; 9. The preparation method according to claim 7, characterized in that, (3) the cold-rolled alloy is subjected to solid solution treatment at 1050℃, and then cooled to obtain the alloy. The total deformation amount of the cold rolling in step (2) is 60%~80%, and the single pass reduction is not more than 10%.

10. Use of the alloy of claim 1 in preparing load-bearing structural parts under high corrosion conditions below 600℃.

Images