A high-toughness wear-resistant nickel-based alloy, preparation method and marine diesel engine frequency regulating wheel alloy casting

Abstract

The present invention belongs to the technical field of nickel-based alloys, and specifically relates to a high-toughness, wear-resistant nickel-based alloy, a preparation method, and a marine diesel engine frequency-regulating wheel alloy casting; the nickel-based alloy is a Ni-Mo series rare earth alloy, comprising Mo, Cr, Al, Fe, Ti, C, and rare earth elements La, Ce, Pr, Nd, with Ni as the balance by mass percentage. By optimizing the composition design and smelting parameters, combined with forging, solution treatment, and multi-stage aging treatment, the precipitation morphology of molybdenum carbide is controlled to achieve its uniform dispersion distribution in the α-Ni matrix; the alloy structure is dense, the molybdenum carbide particles have a particle size of 0.1 to 0.2 μm, a spacing of less than 1 μm, and a second phase volume fraction of 10 to 12%. The material has excellent impact toughness and wear resistance, and is suitable for important components such as marine diesel engine frequency-regulating wheels that bear impact and wear loads for a long time, and has good structural stability and application prospects.

Description

Technical Field

[0001] The present invention belongs to the technical field of nickel-based alloys, and in particular relates to a high-toughness, wear-resistant nickel-based alloy, a preparation method and a marine diesel engine frequency regulating wheel alloy casting. Background Art

[0002] As a key transmission component in marine diesel engines, the frequency regulator (French speed regulator) is widely used to adjust speed matching and power transmission smoothness during engine operation. Its service conditions are often accompanied by high-frequency impact loads, intense vibration, and complex friction and wear environments. Especially under the long-term, high-load operation conditions of ocean-going vessels, the French speed regulator's structural integrity, surface wear resistance, and core toughness directly affect the stability and safety of the entire engine.

[0003] Existing marine diesel engine frequency control impellers are mostly made of ductile iron or medium- and low-alloy steel castings. While these castings possess considerable mechanical properties, they still present numerous challenges in practical use: insufficient toughness leads to poor impact resistance and prone to cracking under complex loads; low wear resistance causes premature wear of the gear teeth or working surfaces, reducing service life; and casting defects such as coarse grains and uneven microstructure can easily lead to premature fatigue failure. Furthermore, conventional casting processes often fail to achieve a synergistic combination of strength and toughness through controlled composition and microstructure, making it difficult to balance surface strengthening with optimized overall mechanical properties.

[0004] In order to improve the service reliability of frequency-regulating wheel castings in harsh marine environments, it is urgent to develop a new type of alloy material with both high toughness and high wear resistance, and at the same time, to match it with innovative heat treatment and surface strengthening processes to further improve the structural uniformity, crack resistance and wear life of the castings, so as to meet the high requirements of modern high-power marine diesel engines for the performance of key transmission components. Summary of the Invention

[0005] In view of the above problems, the object of the present invention is to provide: a high-toughness wear-resistant nickel-based alloy, which comprises the following components in mass percentage: Mo: 11.0-15.0%, Cr: 6.0-9.0%, Al: 0.6-0.9%, Fe: 1.0-2.0%, Ti: 0.2-0.5%, C: 0.02-0.06%, Ni: balance; and further comprises the following rare earth elements as doping elements: La: 0.2-0.3%, Ce: 0.2-0.3%, Pr: 0.1-0.2%, Nd: 0.1-0.2%.

[0006] In a preferred technical solution, the content of oxygen element present as an impurity in the nickel-based alloy is less than 150 ppm.

[0007] In a preferred technical solution, the size of the carbide particles in the microstructure of the nickel-based alloy is 0.1 to 0.2 μm, and the average distance between the carbide particles is less than 5 μm.

[0008] The present invention also provides a method for preparing the high-toughness wear-resistant nickel-based alloy, comprising the following steps:

[0009] S1. Weigh the raw materials of Mo, Cr, Al, Fe, Ti, C, Ni and rare earth elements La, Ce, Pr, and Nd according to mass percentage;

[0010] S2. Melt the above raw materials in a vacuum induction furnace at a melting temperature of 1450-1550°C. Use argon protection to prevent oxidation during the melting process, and stir evenly.

[0011] S3. After smelting is completed, the melt is poured into a dry and preheated metal mold to obtain an alloy casting after molding.

[0012] In a preferred technical solution, the rare earth raw material is added in the form of a rare earth master alloy, and the rare earth master alloy is a mixed alloy of La-Ce-Pr-Nd, and the total rare earth content thereof is controlled at 0.6-1.0%.

[0013] In a preferred technical solution, the oxygen content in the furnace is controlled to be lower than 100 ppm during the entire smelting process, all raw materials are degreased and derusted before smelting, and the nickel-based raw materials are preheated to 200-300°C before being put into the smelting furnace.

[0014] The present invention also provides a marine diesel engine frequency control wheel alloy casting, which is made of the nickel-based alloy as a raw material through an enhanced forging process, wherein the enhanced forging process comprises the following steps:

[0015] A1. Forging process:

[0016] The nickel-based alloy is preheated in the range of 1100-1250° C. and kept warm for more than 30 minutes, and then hot die forged in the range of 500-700° C. using a marine diesel engine frequency control wheel die. After the hot forging is completed, the forging is placed in a slow cooling pit and slowly cooled to room temperature to obtain an initial forged structure;

[0017] A2. Heat treatment process:

[0018] A21. Heating step: placing the forging in a vacuum furnace, heating it to 1170-1220°C at a temperature rise rate of 5-10°C / min, and holding the temperature constant for 5-7 hours; the vacuum degree of the vacuum furnace is maintained at 0.5-1 Pa;

[0019] A22, solid solution step: the heated and heat-insulated forging is rapidly cooled to room temperature to form a solid solution structure;

[0020] A23. Aging step: Heat the cooled forging to 600-650°C and keep it at this temperature for 6-8 hours to promote the precipitation of molybdenum carbide and form a dispersed strengthening phase, then slowly cool it to room temperature in the furnace.

[0021] In a preferred technical solution, in the alloy casting, the particle size of the molybdenum carbide particles is controlled to be no greater than 0.2 μm; and the average spacing is controlled to be less than 1 μm.

[0022] In a preferred technical solution, in the α-Ni phase matrix formed in the alloy casting during the heat treatment process, molybdenum carbide exists in the form of a granular or strip-shaped second phase, the volume fraction of the second phase in the matrix is ​​10-12%, and the diameter of the molybdenum carbide particles is less than 0.2 μm, and the particle spacing is not greater than 1 μm.

[0023] Beneficial effects

[0024] The present invention provides a high-toughness, wear-resistant Ni-Mo rare earth alloy casting for a marine diesel engine frequency regulating wheel and a microstructure control and strengthening process thereof, which solves the technical problems of existing frequency regulating wheel materials such as easy fracture, easy wear, and unstable microstructure under high-load impact and long-term wear conditions, and has the following significant beneficial effects:

[0025] 1. Scientific alloy design and optimized composition matching:

[0026] By controlling the mass fraction range of strengthening elements such as Mo, Cr, Al, and Ti, and introducing a variety of rare earth elements such as La, Ce, Pr, and Nd, and uniformly doping them in the form of rare earth master alloys, the melt purity and grain refinement effect are significantly improved, the uniform precipitation of carbides is promoted, and the overall organizational stability and mechanical property balance of the material are improved.

[0027] 2. Molybdenum carbide strengthening phase is distributed finely and evenly:

[0028] After optimized heat treatment process, a dispersed molybdenum carbide strengthening phase with a particle size of 0.1-0.2μm and a spacing of less than 1μm is formed in the alloy. It is stably distributed in granular or strip form in the α-Ni matrix. The volume fraction of the second phase is controlled at 10-12%, effectively enhancing the wear resistance and crack toughness of the alloy.

[0029] 3. Synergistic improvement of toughness and wear resistance:

[0030] The alloy produced by this invention exhibits excellent energy absorption under impact loads, with an average impact energy absorption exceeding 50 J, and a typical plastic dimple fracture pattern. Furthermore, under high-load friction and wear conditions, it exhibits a low coefficient of friction and minimal wear weight loss, resulting in a smooth and uniform wear surface. Its wear resistance surpasses that of existing Ni-based materials and non-rare earth quenched and tempered alloys.

[0031] 4. Suitable for high-load and high-impact marine environments:

[0032] The material of the present invention is particularly suitable for the manufacture and strengthening of key structural parts such as frequency regulating wheels of marine diesel engines, meeting their service requirements of withstanding high-frequency vibration, impact load and friction and wear during long-term operation, and has good service stability and service life extension effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 EBSD images of Example 1 of the present invention, (a) is a 2000x magnification image, and (b) is a 10000x magnification image;

[0034] Figure 2 is the impact toughness test result of the present invention;

[0035] Figure 3 This is the wear resistance test result of the present invention. DETAILED DESCRIPTION

[0036] In order to deepen the understanding of the present invention, the present invention will be further described in detail below with reference to the examples. The examples are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0037] Example 1 (T1)

[0038] This embodiment provides a nickel-based alloy casting, which is specifically produced by the following steps:

[0039] Alloy ingredients and smelting:

[0040] The following raw materials were weighed according to mass percentage to prepare the alloy: Mo: 13.5%, Cr: 7.2%, Al: 0.8%, Fe: 1.5%, Ti: 0.3%, C: 0.045%, La: 0.25%, Ce: 0.25%, Pr: 0.15%, Nd: 0.15%, and Ni: balance.

[0041] The rare earth elements are added in the form of pre-synthesized La-Ce-Pr-Nd rare earth master alloy, and the total rare earth content is controlled at 0.8%.

[0042] The smelting is carried out in a medium-frequency vacuum induction furnace. The vacuum degree in the furnace is maintained at 0.8 Pa and high-purity argon is filled for protection. The raw materials are preheated to 200-250°C before smelting and are added to the furnace in sequence after degreasing and rust removal. The smelting temperature is controlled at 1500°C and the total smelting time is about 25 minutes.

[0043] After the melt is stirred evenly, it is immediately poured into a metal mold preheated to 350°C. After cooling, the mold is demolded to obtain an alloy casting, which is used as the raw material for subsequent forging.

[0044] Forging process:

[0045] The cast alloy was heated to 1200°C and kept warm for 40 minutes, then hot forged at 630°C with the deformation ratio controlled at 45% to 55%. The forging was then placed in a slow cooling pit and slowly cooled to room temperature to obtain a forged alloy with uniform structure.

[0046] Heat treatment process:

[0047] A21: Heating stage: Place the forging in a vacuum furnace and control the heating rate to 8°C / min. Raise the temperature to 1200°C and keep it constant for 6 hours. The vacuum degree of the vacuum furnace is maintained at 0.6 Pa.

[0048] A22: Solution treatment: After high temperature holding, quickly remove the forging and air cool to room temperature to obtain a solid solution structure;

[0049] A23: Aging treatment: Reheat the cooled forging to 620℃, keep it at this temperature for 7 hours, and then slowly cool it to room temperature in the furnace to promote the precipitation of dispersed molybdenum carbide phase.

[0050] Example 2 (T2)

[0051] This embodiment provides a second nickel-based alloy casting, which is specifically produced by the following steps:

[0052] Alloy ingredients and smelting:

[0053] The following raw materials were weighed according to mass percentage: Mo: 11.0%, Cr: 6.0%, Al: 0.6%, Fe: 1.0%, Ti: 0.2%, C: 0.02%, La: 0.2%, Ce: 0.2%, Pr: 0.1%, Nd: 0.1%, and Ni: balance.

[0054] Rare earth elements are added using La-Ce-Pr-Nd mixed rare earth master alloy, and the total rare earth content is controlled at 0.6%.

[0055] The raw materials were preheated at 200°C before smelting to thoroughly remove oil and scale. They were then smelted in a vacuum induction furnace at 1450°C, with a vacuum maintained at 0.5 Pa. High-purity argon was introduced as a protective atmosphere, and the furnace was stirred for 15 minutes to ensure uniform composition.

[0056] After the melt is degassed and allowed to stand, it is immediately poured into a metal mold preheated to 300° C., and demolded after natural cooling to obtain a cast nickel-based alloy.

[0057] Forging process:

[0058] The cast nickel-based alloy ingot is heated to 1100℃ and kept warm for 30 minutes, and then hot forged at 500℃ with a deformation ratio of not less than 40%. After completion, the forging is slowly placed in a slow cooling pit and cooled to room temperature to obtain the initial forged structure.

[0059] Heat treatment process:

[0060] A21: Heating step: Place the forging in a vacuum furnace and heat it to 1170°C at a heating rate of 5°C / min. Keep it at this temperature for 5 hours. The vacuum degree is controlled at 0.5 Pa.

[0061] A22: Solution treatment: After high temperature holding, the forging is immediately taken out and air-cooled to room temperature to form a solid solution structure;

[0062] A23: Aging treatment: Heat the cooled forging to 600°C, keep it at this temperature for 6 hours, and then slowly cool it to room temperature in the furnace.

[0063] Example 3 (T3)

[0064] This embodiment provides a third nickel-based alloy casting, which is specifically produced by the following steps:

[0065] Alloy ingredients and smelting:

[0066] The following raw materials were weighed according to mass percentage: Mo: 15.0%, Cr: 9.0%, Al: 0.9%, Fe: 2.0%, Ti: 0.5%, C: 0.06%, La: 0.3%, Ce: 0.3%, Pr: 0.1%, Nd: 0.1%, and Ni: balance.

[0067] Rare earth elements are added in the form of La-Ce-Pr-Nd mixed rare earth master alloy, and the total rare earth content is controlled at 1.0%.

[0068] Before smelting, all metal raw materials should be preheated to 300℃ and surface impurities should be thoroughly removed.

[0069] The smelting was carried out in a vacuum induction furnace with the smelting temperature controlled at 1550°C and the vacuum degree controlled at 0.6 Pa. Argon gas was introduced for protection. The smelting process lasted for 30 minutes and strong stirring was performed to ensure uniform composition.

[0070] After smelting, the melt is quickly poured into a metal mold preheated to 400°C, and after natural cooling and demoulding, a cast alloy ingot is obtained.

[0071] Forging process:

[0072] The cast alloy ingot is heated to 1250℃ and kept warm for 45 minutes, and then hot forged at 700℃ with a deformation ratio of more than 60%. After completion, the forging is placed in a slow cooling pit and slowly cooled to room temperature to form a dense forged structure.

[0073] Heat treatment process:

[0074] A21: Heating stage: Place the forging in a vacuum furnace and heat it to 1220°C at a heating rate of 10°C / min. Keep the temperature constant for 7 hours. The vacuum degree is controlled at 1Pa.

[0075] A22: Solution treatment: After the heat preservation, air cool to room temperature immediately to obtain a complete solid solution structure;

[0076] A23: Aging treatment: The cooled forgings are heated to 650°C, kept at this temperature for 8 hours, and then slowly cooled to room temperature in the furnace to promote the full precipitation and dispersion distribution of the molybdenum carbide strengthening phase.

[0077] Comparative Example 1 (C1)

[0078] In order to verify the scientific nature of the ratio range of each element in the present invention and its influence on the alloy structure and properties, this comparative example 1 is designed to provide a nickel-based alloy forging, which is prepared and processed according to conventional processes, as follows:

[0079] The alloy of this comparative example was prepared according to the following mass percentages:

[0080] Mo: 16.5%, Cr: 9.0%, Al: 0.9%, Fe: 2.0%, Ti: 0.5%, C: 0.08%, La: 0.35%, Ce: 0.35%, Pr: 0.25%, Nd: 0.25%, Ni: balance.

[0081] Rare earth elements are added in the form of a La-Ce-Pr-Nd mixed rare earth master alloy with a total rare earth content of 1.2%. Before smelting, the raw materials are preheated to 300°C and the surface is degreased and rust-proofed.

[0082] The alloy was melted in a vacuum induction furnace at 1550°C, with a vacuum level of 0.8 Pa and an argon protective atmosphere. The melting time was 30 minutes. After stirring, the melt was poured into a mold preheated to 400°C and cooled to remove the mold to obtain the cast alloy.

[0083] The ingot was heated to 1250°C and held for 45 minutes. It was then hot forged at 700°C with a 60% deformation ratio and slowly cooled to room temperature. Heat treatment then followed: heating to 1220°C and holding for 7 hours, followed by air cooling, followed by aging at 650°C for 8 hours, and finally furnace cooling.

[0084] Comparative Example 2 (C2)

[0085] This comparative example provides a nickel-based alloy forging, which is prepared by mixing the raw materials according to the following mass percentages:

[0086] Mo: 13.0%, Cr: 7.5%, Al: 0.8%, Fe: 1.5%, Ti: 0.3%, C: 0.045%, Y: 0.3%, Sm: 0.3%, Gd: 0.2%, Ni: balance

[0087] The rare earth elements are added in the form of a mixed rare earth master alloy of Y, Sm and Gd, and the total rare earth content is 0.8%.

[0088] After preheating the raw materials to 300°C and degreasing and rusting the surface, they were melted in a vacuum induction furnace at 1500°C. The vacuum level was controlled at 0.7 Pa and high-purity argon was used for protection. The melting time was 25 minutes. After the melt was thoroughly stirred, it was poured into a metal mold preheated to 350°C and naturally cooled before demolding to obtain the cast alloy.

[0089] The as-cast ingot was heated to 1200°C and kept at this temperature for 40 minutes, hot forged at 650°C with a deformation ratio of 50%, and then slowly cooled to room temperature.

[0090] The heat treatment process includes: heating to 1200℃ and keeping it for 6 hours, then air cooling, then heating to 620℃ and keeping it for 7 hours for aging treatment, and finally cooling with the furnace.

[0091] Comparative Example 3 (C3)

[0092] This comparative example provides a nickel-based alloy forging, which is prepared by mixing the raw materials according to the following mass percentages:

[0093] Mo: 13.0%, Cr: 7.0%, Al: 0.8%, Fe: 1.5%, Ti: 0.3%, C: 0.045%, Ni: balance. This alloy does not contain any rare earth elements. All raw materials are preheated to 250°C, degreased, and derusted. They are then melted in a vacuum induction furnace at 1500°C, maintained at a vacuum of 0.6 Pa, and protected by high-purity argon gas. The melt is then thoroughly stirred for 20 minutes and poured into a mold preheated to 350°C. After natural cooling, the mold is removed to produce the cast alloy.

[0094] The ingot was heated to 1200°C, kept at this temperature for 40 minutes, and then hot forged at 600°C with a deformation ratio of 50%, and then slowly cooled to room temperature.

[0095] The heat treatment adopts the scheme of heating to 1200℃, keeping it for 6 hours, air cooling, and then keeping it at 620℃ for 7 hours and then slowly cooling it in the furnace for strengthening treatment.

[0096] Comparative experiment

[0097] In order to verify the comprehensive performance advantages of the alloy castings provided by the embodiments of the present invention, samples obtained from Example 1 (T1), Example 2 (T2), Example 3 (T3) and Comparative Example 1 (C1), Comparative Example 2 (C2), and Comparative Example 3 (C3) were selected respectively, standard specimens were prepared according to the same size, and impact toughness and wear resistance tests were carried out under the same test conditions.

[0098] (1) Impact toughness test

[0099] Impact toughness test was performed on standard metal impact specimens (10 mm × 10 mm × 55 mm with V-notch) using a standard pendulum impact tester at room temperature. Each sample was tested three times and the average value was taken. The results are shown in Table 1 and plotted. Figure 2 .

[0100] Table 1 Impact toughness test results

[0101]

[0102] (2) Wear resistance test

[0103] The wear resistance test adopts the end face wear method. Under the conditions of room temperature, load 200 N and rotation speed 300 rpm, each sample is rubbed for 60 minutes, and the friction coefficient and wear weight loss are recorded. The test results are shown in Table 2 and plotted. Figure 3 .

[0104] Table 2 Wear resistance test results

[0105]

[0106] Data Analysis

[0107] Combining the impact toughness and wear resistance test data of each group of samples in the table, the following analysis conclusions can be drawn:

[0108] 1. Microscopic morphology:

[0109] like Figure 1 As shown in Example 1, EBSD (electron backscatter diffraction) analysis of the alloy of the present invention reveals a uniform and dense grain structure exhibiting a typical equiaxed morphology. Grain sizes are concentrated between 5 and 12 μm, with no apparent coarse grains or abnormally large regions. A grain boundary misorientation map reveals a high proportion of high-angle grain boundaries and good grain boundary continuity, indicating that the forging and heat treatment processes effectively promote recrystallization and enhance structural stability. Furthermore, the lack of significant texture orientation in the orientation distribution map indicates a random distribution of grain orientations, which promotes isotropic mechanical properties under multiaxial stress states and further enhances the alloy's toughness and service reliability under complex loading conditions.

[0110] 2. Impact toughness performance

[0111] like Figure 2 As shown, the impact absorption energies of T1, T2, and T3 are all greater than 49 J, with T1 achieving the best performance at 52.6 J. The fracture surface features primarily fibrous plastic fracture, indicating the alloy's good plasticity and crack resistance. In contrast, the impact absorption energies of C1 to C3 are all below 40 J, with the lowest being 28.7 J for C3. The fracture surfaces are mostly characterized by cleavage fracture or coarse carbide interpenetration, indicating a strong tendency towards brittle fracture.

[0112] From an alloy design perspective, the synergistic effect of the appropriate Mo content and multiple rare earth elements in the example alloys effectively inhibited carbide coarsening and promoted fine, uniform precipitation, thereby enhancing the alloy's energy absorption capacity under impact loads. However, C1, due to its high Mo and rare earth element content, resulted in excessive precipitation and agglomeration of coarse carbides in the structure, weakening fracture toughness. C2, due to its use of a non-optimized rare earth combination of Y and Sm, exhibited suboptimal carbide precipitation morphology and failed to achieve effective refinement. C3, without the addition of rare earth elements, exhibited a coarse structure and significantly insufficient matrix strengthening.

[0113] 3. Wear resistance performance

[0114] like Figure 3 As shown in the wear test, T1 achieved the lowest wear weight loss of only 6.2 mg, maintaining a stable coefficient of friction at a low 0.38. The wear scars were smooth and had sharp edges, demonstrating excellent wear resistance. The wear weight losses of T2 and T3 were slightly higher than T1, but still far superior to the comparative samples.

[0115] Wear weight loss for C1 to C3 increased significantly, with C3 experiencing the highest wear loss of 13.2 mg. The friction coefficient fluctuated significantly, and the wear scar exhibited severe wear signs such as flaking, galling, and carbide shedding. Analysis revealed that the aging treatment in the examples promoted the uniform and dispersed precipitation of the molybdenum carbide reinforcement phase, effectively preventing abrasive erosion. In contrast, the coarse particles and uneven microstructure in the comparative examples easily formed localized wear channels at stress concentrations, leading to worsening wear.

[0116] 4. Comprehensive performance comparison

[0117] Experimental data shows that T1 exhibits the best overall performance, followed by T2 and T3, all of which offer both high toughness and good wear resistance. T1, through a comprehensive balance of Mo content, rare earth ratio, and heat treatment parameters, forms a dispersed molybdenum carbide reinforcement phase with a particle size of approximately 0.1 to 0.2 μm and an average spacing of less than 1 μm. This forms a stable network structure within the α-Ni matrix, providing the structural support for the material's excellent toughness and stable wear resistance.

[0118] The comparative samples showed varying degrees of performance degradation, including:

[0119] C1: heavier composition and coarser texture;

[0120] C2: The rare earth system is mismatched, and the carbide precipitation morphology is disordered;

[0121] C3: No rare earth added, lack of strengthening mechanism.

[0122] In summary, the experimental data fully verifies the comprehensive advantages of the Ni-Mo rare earth alloy proposed in the present invention in terms of ratio optimization, rare earth synergy, microstructure regulation and heat treatment strengthening. Its performance stability under high-load impact and high-wear service environments is significantly better than that of traditional solutions, and it is particularly suitable for harsh working conditions such as marine diesel engine frequency regulation wheels.

[0123] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A high toughness wear-resistant nickel-based alloy, characterized in that: The high-toughness wear-resistant nickel-based alloy comprises the following components by mass percentage: Mo: 11.0~15.0%, Cr: 6.0~9.0%, Al: 0.6~0.9%, Fe: 1.0~2.0%, Ti: 0.2~0.5%, C: 0.02~0.06%, Ni: balance; The following rare earth elements are also included as doping elements: La: 0.2-0.3%, Ce: 0.2-0.3%, Pr: 0.1-0.2%, Nd: 0.1-0.2%; The size of carbide particles in the microstructure of the nickel-based alloy is 0.1 to 0.2 μm, and the average spacing between carbide particles is less than 5 μm; The high toughness wear-resistant nickel-based alloy is prepared according to the following method: S1. Weigh the raw materials of Mo, Cr, Al, Fe, Ti, C, Ni and rare earth elements La, Ce, Pr, and Nd according to mass percentage; S2. Melt the above raw materials in a vacuum induction furnace at a melting temperature of 1450-1550°C. Use argon protection to prevent oxidation during the melting process, and stir evenly. S3, after smelting is completed, pouring the melt into a dry and preheated metal mold, and obtaining the nickel-based alloy after molding; The rare earth raw material is added in the form of a rare earth master alloy, which is a mixed alloy of La-Ce-Pr-Nd, and the total rare earth content is controlled at 0.6-1.0%.

2. A high toughness wear-resistant nickel-based alloy according to claim 1, characterized in that: The content of oxygen element present as impurities in the nickel-based alloy is less than 150 ppm.

3. The high toughness wear-resistant nickel-based alloy according to claim 1, characterized in that: During the entire smelting process, the oxygen content in the furnace is controlled below 100ppm. All raw materials are degreased and derusted before smelting. The nickel-based raw materials are preheated to 200-300℃ before being put into the smelting furnace.

4. A marine diesel engine frequency control wheel alloy casting, characterized in that: Made of high-toughness wear-resistant nickel-based alloy, the high-toughness wear-resistant nickel-based alloy comprises the following components by mass percentage: Mo: 11.0-15.0%, Cr: 6.0-9.0%, Al: 0.6-0.9%, Fe: 1.0-2.0%, Ti: 0.2-0.5%, C: 0.02-0.06%, Ni: balance; the following rare earth elements are also included as doping elements: La: 0.2-0.3%, Ce: 0.2-0.3%, Pr: 0.1-0.2%, Nd: 0.1-0.2%; The forging process comprises the following steps: A1. Forging process: The nickel-based alloy is preheated in the range of 1100-1250° C. and kept warm for more than 30 minutes, and then hot die forged in the range of 500-700° C. using a marine diesel engine frequency control wheel die. After the hot forging is completed, the forging is placed in a slow cooling pit and slowly cooled to room temperature to obtain an initial forged structure; A2. Heat treatment process: A21. Heating step: placing the forging in a vacuum furnace, heating it to 1170-1220°C at a temperature rise rate of 5-10°C / min, and holding the temperature constant for 5-7 hours; the vacuum degree of the vacuum furnace is maintained at 0.5-1 Pa; A22, solid solution step: the heated and heat-insulated forging is rapidly cooled to room temperature to form a solid solution structure; A23, aging step: the cooled forging is heated to 600-650℃ and kept at this temperature for 6-8 hours to promote the precipitation of molybdenum carbide and form a dispersed strengthening phase, and then slowly cooled to room temperature in the furnace; In the α-Ni phase matrix formed in the alloy casting during the heat treatment process, molybdenum carbide exists in the form of a granular or strip-shaped second phase, the volume fraction of the second phase in the matrix is ​​10-12%, the diameter of the molybdenum carbide particles is less than 0.2 μm, and the particle spacing is no more than 1 μm.

5. The marine diesel engine frequency regulating wheel alloy casting according to claim 4, characterized in that: In the alloy casting, the particle size of the molybdenum carbide particles is controlled to be no greater than 0.2 μm; and the average spacing is controlled to be less than 1 μm.

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