A high-strength, high-hardness high-temperature alloy and preparation method thereof

Abstract

The present invention relates to a high-strength, high-hardness high-temperature alloy and a preparation method thereof. The high-temperature alloy comprises, by weight percentage, the following components: C: 0.02-0.05%, Si: 0-0.1%, Mn: 0-0.1%, S: 0-0.015%, P: 0-0.015%, Cr: 17.5-18.5%, Fe: 0-10.0%, Al: 1.6-1.8%, Co: 4.0-4.5%, Ti: 0.75-1.15%, Nb: 5.6-5.8%, B: 0-0.006%, Mg: 0-0.01%, and the balance is Ni and unavoidable impurities. The preparation method comprises: step S1 of mixing raw materials according to the composition ratio, performing vacuum induction smelting, pouring molten steel, and obtaining steel ingots by vacuum consumable remelting; step S2 of heating, forging, solution treatment and aging treatment of the steel ingot; step S3 of polishing, vacuum consumable remelting, homogenization treatment and reheating and forging the forged vacuum induction electrode to obtain a high-strength, high-hardness high-temperature alloy. The smelting process and heat treatment process adopted by the present invention effectively improve the mechanical properties, hot working properties and corrosion resistance of the material, and solve the deficiencies of traditional high-temperature alloys in hardness and thermal strength.

Description

Technical Field

[0001] The present invention relates to the technical field of alloy preparation, and in particular to a high-strength, high-hardness high-temperature alloy and a preparation method thereof. Background Art

[0002] High-temperature alloy is a material that can be used for a long time in high temperature and high stress environment. It has good anti-oxidation, anti-corrosion and high strength properties. Therefore, it is widely used in aerospace, energy and chemical industries. For example, 718 high-temperature alloy plays an important role in the manufacture of aircraft engines, gas turbines, chemical containers and pipelines due to its excellent heat resistance and mechanical properties. In addition, 718 alloy is also widely used in the mold industry, such as injection molds and die-casting molds. The mold material needs to work for a long time under high temperature and high pressure, which places extremely high demands on the hardness, fatigue resistance and service life of the material.

[0003] However, the existing 718 high-temperature alloy has some obvious shortcomings. First, the hardness of ordinary 718 alloy is relatively low, usually only between 42 and 45HRC, which is difficult to meet the requirements of high-strength and high-hardness application scenarios, such as the manufacture of hot working punches, and its service life is usually less than 300 times. Secondly, the proportion of certain components of the existing 718 alloy limits the potential of its strengthening mechanism. For example, the total content of its strengthening elements Al+Ti+Nb is about 7.3%, and the strengthening effect is limited; at the same time, the control of the C content in the alloy is not precise enough, and segregation phases such as NbC are easily formed, resulting in the appearance of "black spot" defects, which in turn affects the mechanical properties and corrosion resistance of the material. In addition, the hot working temperature range of the 718 alloy is wide, but the hot working plasticity is insufficient, which increases the difficulty of the yield rate, especially in the manufacturing process, problems such as cracks and grain growth are prone to occur.

[0004] To solve the above problems, researchers have tried to improve the performance of 718 alloy by optimizing alloy composition and preparation process in recent years. For example, by increasing the content of strengthening elements (such as Al, Nb, Co) to increase the amount of γ′ and γ″ phases in the alloy, the high temperature strength and hardness of the material can be significantly improved. However, this composition optimization usually brings other challenges, such as an increased tendency to form Laves phase, resulting in decreased impact performance. In addition, high-strength and high-hardness materials have higher deformation resistance during processing, and processing plasticity is significantly reduced, further increasing manufacturing costs and process complexity.

[0005] In summary, the existing technology still has many bottlenecks in the development and preparation of high-strength, high-hardness high-temperature alloys, including insufficient hardness, unbalanced mechanical properties, difficulty in processing, and poor high-temperature stability. There is an urgent need for a new high-temperature alloy composition system and its preparation process to ensure the high strength and high hardness of the material while taking into account its processing performance and high-temperature fatigue resistance to meet the demand for high-performance alloy materials in modern industrial applications. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a high-strength, high-hardness high-temperature alloy to solve the problems of insufficient strength and hardness, poor hot working performance and short durability of conventional similar alloys in the prior art.

[0007] In order to overcome the above defects of the prior art, the present invention provides a high-strength, high-hardness high-temperature alloy, characterized in that its components by weight percentage include:

[0008] C: 0.02-0.05%, Si: 0-0.1%, Mn: 0-0.1%, S: 0-0.015%, P: 0-0.015%, Cr: 17.5-18.5%, Fe: 0-10.0%, Al: 1.6-1.8%, Co: 4.0-4.5%, Ti: 0.75-1.15%, Nb: 5.6-5.8%, B: 0-0.006%, Mg: 0-0.01%, and the balance is Ni and unavoidable impurities.

[0009] Compared with the prior art, the high-strength, high-hardness high-temperature alloy provided by the present application has the following advantages: on the basis of the existing 718 alloy, the content of strengthening elements such as Al, Nb, and Co is significantly increased by precisely controlling the alloy composition. The increase in the Al and Nb content increases the number of γ′ and γ″ strengthening phases in the alloy, thereby enhancing the solid solution strengthening and aging strengthening effects, and further improving the strength and hardness of the alloy. At the same time, by controlling the C content at a lower level (0.02-0.05%), the generation of NbC is effectively reduced, the probability of the occurrence of "black spot" defects is reduced, and the purity and uniformity of the material are improved; by further controlling the content of Al, Nb and Co, the strength and hardness of the alloy are synergistically improved: the Al content is increased to 1.6-1.8%, which strengthens the formation of the γ′ phase, inhibits the precipitation of the δ phase, and improves the mechanical properties of the alloy; the Nb content is increased to 5.6-5.8%, which increases the number of γ″ phases and improves the high-temperature strength and hardness; the Co content is increased to 4.0-4.5%, which helps to stabilize the γ′ strengthening phase, inhibit its coarsening, improve creep performance and thermal strength performance, and make the material have more stable deformation resistance in high temperature environment; by strictly controlling the content of impurity elements such as P, S, B, Mg, especially controlling P and S to less than 0.015%, B to less than 0.006%, and Mg to less than 0.01%, the purity of the material is significantly improved, the influence of inclusions is reduced, and the hot processing plasticity and comprehensive performance are improved. Compared with existing conventional alloys, the high-temperature alloy of the present invention has improved hardness and strength while maintaining good processing plasticity, especially has stronger stability and corrosion resistance at high temperature, and is suitable for high-temperature component applications in the fields of aerospace, energy equipment and chemical industry.

[0010] In one possible embodiment, the composition includes by weight percentage: C: 0.025-0.035%, Si: 0-0.08%, Mn: 0-0.05%, S: 0-0.010%, P: 0-0.010%, Cr: 17.7-18.0%, Fe: 0-9.0%, Mo: 2.80-3.20%, Co: 4.20-4.40%, Al: 1.70-1.90%, Ti: 0.95-1.10%, Nb: 5.60-5.80%, B: 0.003-0 .006%, Mg: 0-0.010%, Ni: 56.50-58.50%, the impurity components include: Cu: 0-0.1%, Ca: 0-0.005%, Bi: 0-0.00003%, Sn: 0-0.005%, Pb: 0-0.0005%, Ag: 0-0.0005%, Se: 0-0.0003%, Te: 0-0.00005%, Tl: 0-0.0001%, H: 0-5ppm, O: 0-50ppm, N: 0-50ppm.

[0011] Compared with the prior art, the above technical scheme is adopted to further refine the alloy composition, especially under the precise control of strengthening elements such as C, Al, Nb and Co, which significantly improves the mechanical properties and high temperature stability of the alloy. By optimizing the C content (0.025-0.035%), the formation of carbides is reduced, black spot defects are effectively avoided, and the surface quality of the alloy is improved. At the same time, the content of Al (1.70-1.90%) and Nb (5.60-5.80%) is moderately increased, the formation of γ' and γ" phases is enhanced, the solid solution strengthening and aging strengthening effects of the alloy are improved, and the hardness and high temperature fatigue resistance of the alloy are further improved. The increase of Co (4.20-4.40%) effectively enhances the stability of the γ' phase of the alloy and inhibits its growth, thereby improving the creep performance and thermal strength performance of the alloy and extending the service life of the material. In addition, by precisely controlling the content of impurity elements such as S, P, H and O, the negative impact of harmful elements on the alloy performance is reduced, and the corrosion resistance and processing performance of the alloy are further improved.

[0012] Another technical problem to be solved by the present invention is to provide a method for preparing the high-strength, high-hardness high-temperature alloy, so as to solve the problems of insufficient strength at high temperature, low hardness, severe segregation and inclusions existing in the alloys prepared by conventional preparation methods in the prior art.

[0013] In order to overcome the above defects of the prior art, a method for preparing the high-strength and high-hardness high-temperature alloy is provided, which is characterized by comprising the following steps:

[0014] S1: Mix the raw materials according to the composition ratio of the high-strength, high-hardness high-temperature alloy, perform vacuum induction smelting, then pour molten steel and vacuum consumable remelting to obtain a steel ingot, wherein the refining temperature of the vacuum induction smelting is 1580±10°C, and the refining time is ≥60min;

[0015] S2: subjecting the steel ingot obtained in step S1 to heating forging, solution treatment and aging treatment to obtain a vacuum induction electrode;

[0016] S3: The vacuum induction electrode obtained in step S2 is subjected to lathing, vacuum consumable remelting, homogenization treatment and reheating and forging treatment to obtain a high-strength, high-hardness high-temperature alloy, wherein the melting rate of the vacuum consumable remelting is 3 kg / min.

[0017] Compared with the prior art, the preparation method of a high-strength and high-hardness high-temperature alloy provided by the present application has the following advantages: in step S1, by accurately controlling the process conditions of vacuum induction smelting, especially controlling the temperature at 1580±10℃ during the refining period, and the refining time ≥60min, the high purity of the molten steel is ensured, the harmful impurities and inclusions in the molten steel are effectively removed, and the performance stability of the alloy is further improved. In step S3, the vacuum consumable remelting process adopts a short arc melting technology with a melting rate of 3kg / min, combined with high vacuum conditions, to effectively remove residual gas and high vapor pressure impurities, reduce the segregation and inclusion defects of the ingot, and significantly improve the uniformity of the crystal structure. At the same time, by controlling the short arc melting of the droplet, the density and organizational stability of the ingot are enhanced. By optimizing the composition design and process control, the technical problems of the existing high-temperature alloys at high temperatures, such as insufficient strength, low hardness, severe segregation, and many inclusions, are solved, providing a high-temperature alloy material with excellent performance and controllable cost for high-end fields such as aerospace, energy, and chemical industry, with broad industrial application prospects.

[0018] In a possible implementation, in step S1, the conditions of the vacuum induction smelting are: the vacuum degree in the preheating period is controlled at ≤50Pa, the vacuum degree in the raw material melting period is controlled at ≤20Pa, and the vacuum degree in the refining period is ≤1.0Pa.

[0019] Compared with the prior art, the above technical solution can be used to gradually reduce the vacuum degree (preheating period ≤50Pa, melting period ≤20Pa, refining period ≤1.0Pa) in the vacuum smelting process, which can effectively remove gas impurities such as oxygen, nitrogen, and hydrogen in the raw materials. Especially when the vacuum degree is controlled at ≤1.0Pa in the refining stage, it is helpful to further reduce the oxygen content and nitrogen content in the molten steel to achieve a high purity effect. By gradually increasing the vacuum degree, the molten steel can volatilize and remove impurity elements with high vapor pressure at high temperature, reduce the formation of inclusions in the alloy, and inhibit the irregular precipitation of inclusions. Alloy elements such as Al, Ti, and Nb can be fully dissolved and evenly distributed in the matrix, effectively reducing the phenomenon of component segregation and structural inhomogeneity, and improving the component stability of the molten steel. .

[0020] In a possible implementation, in the step S1, the temperature of the pouring molten steel is 1530±10°C.

[0021] Compared with the existing technology, the above technical solution can improve the casting performance and crystallization quality of the alloy, reduce segregation and other casting defects, and improve the physical and mechanical properties of the ingot by optimizing the pouring temperature of the molten steel to 1530±10℃. Ultimately, the high-strength, high-hardness high-temperature alloy obtained has higher stability, high temperature resistance and longer service life, meeting the stringent requirements of high-end application fields for material performance, such as aerospace, energy and high-temperature industrial equipment.

[0022] In a possible implementation, in step S2, the heating forging conditions are: heating the steel ingot to 1120°C at a heating rate of ≤150°C / h, and keeping it warm for 30 hours; then continuing to heat it to 1160°C, and keeping it warm for 30 hours; heating it again to 1200°C, keeping it warm for 72 hours, performing homogenization heat treatment, and then cooling it to 1080-1110°C, keeping it warm for 3-4 hours, and forging it out of the furnace. During the forging, the start forging temperature is 1000-1050°C, and the final forging temperature is ≥900°C.

[0023] Compared with the prior art, the above technical solution is adopted to avoid the thermal stress problem caused by the large temperature gradient inside the steel ingot caused by a single rapid heating by gradually heating up in stages, and at the same time, the alloy elements are fully diffused, segregation is reduced, and the uniformity of the structure is improved. The homogenization treatment of keeping at 1200℃ for 72h further inhibits the formation of δ phase and other brittle phases, and promotes the formation of γ' and γ" strengthening phases. These strengthening phases can significantly improve the tensile strength and hardness of the material. At the same time, the opening forging temperature (1000-1050℃) ensures that the material has a low deformation resistance, which is convenient for large deformation forging and reduces the risk of cracks during processing; the final forging temperature (≥900℃) retains the δ phase to the maximum extent, and improves the high-temperature creep performance of the material; the above-mentioned heating forging scheme of the present invention achieves the excellent plasticity and toughness of the high-temperature alloy while maintaining high strength and high hardness, and overcomes the problems of easy segregation, brittle phase precipitation and poor processing performance of the high-temperature alloy in the prior art.

[0024] In a possible embodiment, in step S2, the conditions of the solution treatment are: controlling the charging temperature to be less than or equal to 300°C, charging the steel ingot into the furnace, controlling the heating rate to be ≤100°C / h, raising the temperature of the steel ingot to 900°C±10°C and keeping it warm for 1.5h; then heating the steel ingot for 2 hours to further raise the temperature of the steel ingot to 980°C±10°C, keeping it warm for a×d+tmin, where a is 1.5-1.8, d is the diameter of the steel billet in mm, and t is 5-10; water cooling treatment; the conditions of the aging ...

[0025] ≤100℃ / h, raise the temperature of the ingot to 720±10℃ and keep it for 10h; then cool it down to 620±10℃ at a rate of 30-50℃ / h and keep it for 18h, then take it out of the furnace for air cooling.

[0026] Compared with the prior art, the above technical scheme allows the alloy elements to be fully dissolved into the austenite matrix by the solid solution treatment at 980℃±10℃ for a×d+t time, effectively eliminating the component segregation problem caused by hot working or casting; the water cooling treatment quickly "freezes" the solid solution strengthening phase in the matrix, avoiding the precipitation of secondary phases and the generation of δ phases, thereby maximizing the solid solution strengthening effect of the material; and the preliminary aging treatment at 720℃±10℃ for 10 hours promotes the precipitation and uniform distribution of γ′ and γ″ strengthening phases in the alloy. The precipitated phase significantly enhances the yield strength and hardness of the material; the subsequent secondary aging process of cooling the temperature to 620℃±10℃ at a rate of 30-50℃ / h and keeping it warm for 18 hours can further optimize the size and amount of the precipitated phase and improve the long-term creep resistance of the alloy. The air cooling treatment after the furnace effectively avoids the excessive growth of the precipitated phase, thereby maintaining the good mechanical properties of the alloy; through the synergistic effect of solution treatment and aging treatment, the above technical scheme solves the problems of composition segregation, insufficient strengthening effect and improper control of precipitation phase existing in high-temperature alloys in the prior art.

[0027] In a possible implementation, in the step S3, the vacuum degree of the vacuum consumable remelting is less than 0.1 Pa, and the vacuum consumable remelting adopts droplet-controlled short arc melting.

[0028] Compared with the existing technology, the above technical solution controls the vacuum degree below 0.1Pa, which helps to more efficiently remove gas impurities and high vapor pressure impurities (such as oxygen, nitrogen, etc.) in the molten steel, thereby improving the purity of the molten steel, helping to reduce adverse chemical reactions such as oxidation and nitridation, reduce the content of inclusions in the alloy, and improve the mechanical properties and corrosion resistance of the material; and the short arc melting technology makes the melting of the alloy more uniform by precisely controlling the size of the molten droplet and the short circuit between the molten droplet and the arc. Droplet control can effectively reduce excessive boiling and splashing of molten steel, reduce oxidation and other adverse reactions during the smelting process, and thus improve the purity and crystal quality of the alloy. .

[0029] In a possible implementation, in step S3, the homogenization treatment conditions are:

[0030] The charging temperature of the consumable steel ingot is controlled to be 700℃ before loading into the furnace, and the temperature in the furnace is controlled to rise to 750℃ and kept at this temperature for 10 hours;

[0031] Carry out the first heating, raise the temperature to 1120±10℃, the heating time is 10 hours, and the first heat preservation is 30 hours;

[0032] Carry out the second heating, raise the temperature to 1160±10℃, the heating time is 5 hours, and the second heating is kept for 24 hours;

[0033] The third heating is carried out to raise the temperature to 1195±10°C for 3 hours and the third heating is kept for 72 hours;

[0034] The first cooling is performed to reduce the temperature to 1120±10℃ for 6 hours, and the fourth heating is performed to keep the temperature for 10 hours;

[0035] Carry out the second cooling, lower the temperature to 550±10℃, the cooling time is 10 hours, and then take it out of the furnace and air cool it.

[0036] Compared with the prior art, the above technical solution can effectively promote the uniform diffusion of elements in the alloy, reduce component segregation and the formation of unfavorable phases such as δ phase and Laves phase, thereby optimizing the microstructure of the alloy by gradually increasing the temperature and keeping the temperature within a specific temperature range. In particular, long-term heat preservation at 1195℃±10℃ for 72 hours can fully eliminate dendrite segregation in the as-cast structure, promote the dissolution of the precipitated phase, and make the structure of the alloy more uniform and refined. Continuing to cool and keep the temperature for multiple times, especially the second cooling to 550℃±10℃, can stabilize the γ' and γ" strengthening phases in the alloy, and avoid the accumulation of thermal stress and organizational stress, thereby improving the subsequent processing performance and thermodynamic stability of the material. The homogenization treatment process greatly improves the uniformity and comprehensive performance of the alloy through fine temperature and time control, and shows significant advantages in solving the problems of segregation and poor processing performance in the prior art.

[0037] In a possible implementation, in step S3, the conditions for the reheating forging treatment are: charging the vacuum induction electrode into the furnace at a temperature of ≤300°C, and heating it to 900°C±10°C at a heating rate of not more than 100°C / h, and keeping it warm for 3 hours; further heating it to 1080°C±10°C, the heating time is 2 hours, and keeping it warm for 3.5 to 4 hours; the forging start temperature is 1050°C, and the forging treatment is carried out, and the forging temperature in the blanking stage is 1080-1110°C, the temperature in the later stage of forging is 1010-1050°C, and the final forging temperature is ≥880°C.

[0038] Compared with the prior art, the above technical scheme can slowly eliminate the stress inside the material through segmented heating and heat preservation operations, and at the same time, homogenize the distribution of components in the alloy, and reduce the crack sensitivity caused by work hardening and organizational stress; and reaching a high temperature of 1080-1110°C before forging helps to reduce the deformation resistance of the alloy, increase the plasticity of the material, and ensure the stability of the forging process; and large deformation forging at a high temperature of 1080-1110°C in the blanking stage can avoid crack propagation caused by low-temperature processing, and reduce grain coarsening. The temperature is reduced to 1010-1050°C in the later stage of forging, which is conducive to controlling the grain size and inhibiting the excessive growth of dynamic recrystallization; ensuring that the final forging temperature is not lower than 880°C, the appropriate content of δ phase in the alloy can be retained to the maximum extent, thereby improving the toughness and strength of the material; this embodiment solves the problems of forging cracks, uneven organization and insufficient mechanical properties in the prior art through reasonable segmented heating and precise forging temperature control, so that the alloy has higher strength, hardness and high temperature resistance, and at the same time achieves excellent balance between machinability and toughness. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a heat treatment curve diagram of the homogenization treatment in step S3 of the preparation method of the present invention;

[0040] Figure 2 It is a heat treatment curve diagram of reheating and forging in step S3 of the preparation method of the present invention;

[0041] Figure 3 is a heat treatment curve diagram of the solution treatment in step S3 of the preparation method of the present invention;

[0042] Figure 4 It is a heat treatment curve diagram of the aging treatment in step S3 of the preparation method of the present invention. DETAILED DESCRIPTION

[0043] First, those skilled in the art should understand that these implementations are only used to explain the technical principles of the embodiments of the present application, and are not intended to limit the protection scope of the embodiments of the present application. Those skilled in the art can make adjustments to them as needed to adapt to specific application scenarios.

[0044] The present invention provides a high-strength, high-hardness high-temperature alloy, the components of which include, by weight percentage:

[0045] C: 0.02-0.05%, Si: 0-0.1%, Mn: 0-0.1%, S: 0-0.015%, P: 0-0.015%, Cr: 17.5-18.5%, Fe: 0-10.0%, Al: 1.6-1.8%, Co: 4.0-4.5%, Ti: 0.75-1.15%, Nb: 5.6-5.8%, B: 0-0.006%, Mg: 0-0.01%, and the balance is Ni and unavoidable impurities.

[0046] A simple analysis is made of the improvement of the alloy composition system of the high-strength, high-hardness high-temperature alloy provided by the present invention. Compared with ordinary 718, the Al and Nb contents are further increased to increase the amount of γ′ and γ″ in the alloy, thereby improving the solid solution strengthening and aging strengthening effects, and improving the hardness and strength of the parts. Due to the increase in Nb content, C is further reduced on the basis of the original C content, from 0.03-0.05 to 0.01-0.02, thereby reducing the amount of NbC generated and reducing the probability of "black spot" defects in the material. The Al content is increased by about 0.6% compared to ordinary 718, which greatly inhibits the generation of δ phase, thereby indirectly promoting the amount of γ″ generated. However, excessive increase in Al will greatly increase the generation temperature and amount of LAVES phase, greatly reducing the impact performance, which needs to be improved by increasing and extending the high-temperature homogenization temperature and time. The Co content is increased by about 4%. The addition of Co increases the γ′ strength, inhibits the growth of γ′, and greatly reduces the stable creep rate of the alloy, thereby improving the thermal strength of the alloy.

[0047] The present invention optimizes and improves the alloy component system based on the 718 component, adds relatively high Al, Nb, and Co elements, reduces the content of P, S, C, and participating gases, and cooperates with each other to make the prepared high-temperature alloy have a hardness of 48-52HRC, a room temperature tensile strength of ≥1450Mpa, a room temperature yield strength of ≥1200Mpa, and a tensile strength of 650℃.

[0048] ≥1200Mpa, 650℃ yield strength ≥1000Mpa, and the room temperature impact can still be maintained at ≥30J.

[0049] As a preferred solution, its components include by weight percentage: C: 0.025-0.035%, Si: 0-0.08%, Mn: 0-0.05%, S: 0-0.010%, P: 0-0.010%, Cr: 17.7-18.0%, Fe: 0-9.0%, Mo: 2.80-3.20%, Co: 4.20-4.40%, Al: 1.70-1.90%, Ti: 0.95-1.10%, Nb: 5.60-5.80%, B: 0.003-0.0 06%, Mg: 0-0.010%, Ni: 56.50-58.50%, the impurity components include: Cu: 0-0.1%, Ca: 0-0.005%, Bi: 0-0.00003%, Sn: 0-0.005%, Pb: 0-0.0005%, Ag: 0-0.0005%, Se: 0-0.0003%, Te: 0-0.00005%, Tl: 0-0.0001%, H: 0-5ppm, O: 0-50ppm, N: 0-50ppm.

[0050] The present invention also provides a method for preparing the high-strength, high-hardness high-temperature alloy, comprising the following steps:

[0051] S1: Mix the raw materials according to the composition ratio of the high-strength, high-hardness high-temperature alloy, perform vacuum induction smelting, then pour molten steel and vacuum consumable remelting to obtain a steel ingot, wherein the refining temperature of the vacuum induction smelting is 1580±10°C, and the refining time is ≥60min;

[0052] S2: subjecting the steel ingot obtained in step S1 to heating forging, solution treatment and aging treatment to obtain a vacuum induction electrode;

[0053] S3: The vacuum induction electrode obtained in step S2 is subjected to lathing, vacuum consumable remelting, homogenization treatment and reheating and forging treatment to obtain a high-strength, high-hardness high-temperature alloy, wherein the melting rate of the vacuum consumable remelting is 3 kg / min.

[0054] As a preferred solution, in step S1, the conditions for vacuum induction smelting are: the vacuum degree in the preheating period is controlled at ≤50Pa, the vacuum degree in the raw material melting period is controlled at ≤20Pa, and the vacuum degree in the refining period is ≤1.0Pa.

[0055] As a preferred solution, in step S1, the temperature of the poured molten steel is 1530±10°C.

[0056] The specific operation details of step S1 are shown in Table 1 below:

[0057] Table 1: Specific operation details of step S1

[0058]

[0059] As a preferred solution, in step S2, the heating forging conditions are: heating the steel ingot at a heating rate of ≤150°C / h to 1120°C and keeping it warm for 30 hours; then continuing to heat it to 1160°C and keeping it warm for 30 hours; heating it again to 1200°C and keeping it warm for 72 hours, performing homogenization heat treatment, then cooling it to 1080-1110°C and keeping it warm for 3-4 hours, and then taking it out of the furnace for forging. During the forging, the start forging temperature is 1000-1050°C, and the final forging temperature is ≥900°C.

[0060] The key to the forging process of the present invention is to use a high temperature of 1080-1110°C for large deformation forging in the blanking stage, at which the alloy has a low deformation resistance. In the later stage of forging, a lower temperature of 1010-1050°C is used for structural inheritance, and a shorter tempering time is used to retain the fine grain structure in the blanking stage, while controlling the final forging temperature ≥880°C to retain the δ phase to the greatest extent.

[0061] As a preferred solution, in step S2, the conditions for the solution treatment are: controlling the charging temperature to be less than or equal to 300°C, charging the steel ingot into the furnace, controlling the heating rate to be ≤100°C / h, raising the temperature of the steel ingot to 900°C±10°C and keeping it warm for 1.5h; then heating the steel ingot for 2 hours to further raise the temperature of the steel ingot to 980°C±10°C, keeping it warm for a×d+t min, where a is 1.5-1.8, d is the diameter of the steel billet in mm, t is 5-10, and water cooling treatment; the conditions for the aging treatment are: controlling the charging temperature to be less than or equal to 300°C, charging the steel ingot into the furnace, controlling the heating rate to be ≤100°C / h, raising the temperature of the steel ingot to 720±10°C and keeping it warm for 10h; then cooling the temperature to 620±10°C at a cooling rate of 30-50°C / h and keeping it warm for 18h, and air cooling treatment after taking it out of the furnace. The heat treatment diagrams for solution treatment and aging treatment are as shown in FIG. Figure 3 / 4 as shown.

[0062] The preferred solid solution + aging heat treatment method in the present invention can fully dissolve the alloy elements into austenite, making the alloy composition more uniform, reducing the anisotropy of the material caused by uneven composition, stabilizing the alloy strengthening effect, and improving the comprehensive performance of the material. At the same time, the alloy strong phase is dissolved, while ensuring its basic mechanical properties, it also improves the subsequent processing plasticity of the material.

[0063] As a preferred solution, in step S3, the vacuum degree of the vacuum consumable remelting is less than 0.1 Pa, and the vacuum consumable remelting adopts droplet-controlled short arc melting.

[0064] As a preferred solution, in step S3, the homogenization treatment is as follows: Figure 1 As shown, the conditions are:

[0065] The charging temperature of the consumable steel ingot is controlled to be 700℃ before loading into the furnace, and the temperature in the furnace is controlled to rise to 750℃ and kept at this temperature for 10 hours;

[0066] Carry out the first heating, raise the temperature to 1120±10℃, the heating time is 10 hours, and the first heat preservation is 30 hours;

[0067] Carry out the second heating, raise the temperature to 1160±10℃, the heating time is 5 hours, and the second heating is kept for 24 hours;

[0068] The third heating is carried out to raise the temperature to 1195±10°C for 3 hours and the third heating is kept for 72 hours;

[0069] The first cooling is performed to reduce the temperature to 1120±10℃ for 6 hours, and the fourth heating is performed to keep the temperature for 10 hours;

[0070] Carry out the second cooling, lower the temperature to 550±10℃, the cooling time is 10 hours, and then take it out of the furnace and air cool it.

[0071] As a preferred solution, in step S3, the conditions for the reheating forging treatment are: the vacuum induction electrode is charged into the furnace at a temperature of ≤300°C, and the temperature is increased to 900°C±10°C at a heating rate of not more than 100°C / h, and the temperature is kept for 3 hours; the temperature is further increased to 1080°C±10°C, the heating time is 2 hours, and the temperature is kept for 3.5 to 4 hours; the forging start temperature is 1050°C, and the forging treatment is carried out, and the forging temperature in the blanking stage is 1080-1110°C, the temperature in the later stage of forging is 1010-1050°C, and the final forging temperature is ≥880°C, such as Figure 4 shown.

[0072] In combination with the above technical solution, an embodiment combined with specific data is provided below to further explain the above technical solution of the present invention:

[0073] Embodiment 1:

[0074] This embodiment provides a high-strength, high-hardness high-temperature alloy and a preparation method thereof. The high-strength, high-hardness high-temperature alloy includes the following components in mass fraction:

[0075] C: 0.025%, Mn: ≤0.053%, P: 0.006%, S: 0.001%, Si: ≤0.03%, Cr: 17.70~18.00%, Fe: 8.25%, Mo: 3.05%, Co: 4.32%, Al: 1.78%, Ti: 1.05%, Nb: 5.72%, B: 0.004%, Mg: ≤0.010%, Cu: ≤0.1%, Ca: ≤0.005%, Bi: ≤0.00003%, Sn: ≤0.005%, Pb: ≤0.0005%, Ag: ≤0.0005%, Se: ≤0.0003%, Te: ≤0.00005%, Tl: ≤0.0001%, H: ≤2ppm, O: ≤17ppm, N: ≤25ppm, and the balance is Ni.

[0076] The preparation method comprises the following steps:

[0077] S1: Vacuum induction smelting and pouring:

[0078] Raw material ratio and furnace charging: according to the ratio of the alloy components, the raw materials are loaded into the vacuum induction furnace layer by layer. First add the main raw materials such as Ni, Cr, Mo, and then add the carburizer and other trace elements.

[0079] Smelting conditions: complete preheating and raw material melting under a vacuum degree of ≤50Pa; control the vacuum degree during melting to ≤20Pa, and perform refining after full melting; control the temperature during refining to 1580℃, the time ≥60min, maintain the vacuum degree ≤1.0Pa during refining, and in the vacuum induction furnace smelting process, start melting the materials at a vacuum induction furnace below ≤50Pa, deduct metal chromium, aluminum, and titanium alloy, and add metal chromium after the nitrogen of the fully melted materials is measured to be ≤50ppm. After all materials are melted, perform refining in the vacuum induction furnace at ≤1.0Pa for 75min, and add metal aluminum and titanium when the oxygen content and nitrogen content are both lower than 30PPM;

[0080] Casting conditions: Pour the molten steel into a steel ingot mold preheated to 800°C, and control the casting temperature to 1530°C to obtain a steel ingot.

[0081] S2: Heating forging and heat treatment:

[0082] Heating forging:

[0083] Homogenization treatment:

[0084] The steel ingot is heated to 1120°C at a heating rate of ≤150°C / h and kept at this temperature for 30 hours; the temperature is further raised to 1160°C and kept at this temperature for 30 hours; the temperature is again raised to 1200°C and kept at this temperature for 72 hours.

[0085] Forging stage: the steel ingot after homogenization treatment is cooled to 1095℃, kept at this temperature for 3.5 hours and then taken out of the furnace for forging; the forging starting temperature is 1025℃, and the final forging temperature is ≥900℃.

[0086] Solution treatment:

[0087] The forged steel billet is loaded into the furnace, and the loading temperature is controlled to be ≤300°C; the heating rate is controlled to be ≤100°C / h, the temperature of the steel billet is raised to 900°C, and kept at this temperature for 1.5 hours; the temperature is raised to 980°C again, and the heating time is 2 hours. The holding time is calculated according to the formula a×d+t, where a is 1.65, d is the diameter of the steel billet (in mm), and t is 7.5; and then water-cooled.

[0088] Aging treatment:

[0089] The billet after solution treatment is loaded into the furnace, and the loading temperature is controlled to be ≤300°C; the temperature is raised to 720°C and kept at this temperature for 10 hours; the temperature is lowered to 620°C at a rate of 40°C / h, and kept at this temperature for 18 hours, and then the billet is taken out of the furnace for air cooling.

[0090] S3: Reheating, forging and homogenization treatment:

[0091] After the steel ingot obtained in step S2 is polished, vacuum consumable remelting is performed: vacuum consumable remelting is performed under a vacuum condition of ≤0.1 Pa, a droplet-controlled short arc melting method is adopted, and the melting rate is controlled to be 3 kg / min.

[0092] Then homogenize:

[0093] Control the charging temperature of the furnace at 700℃ and then load the furnace, heat it to 750℃ and keep it warm for 10 hours; heat it to 1120℃ for the first time, heat it up for 10 hours and keep it warm for 30 hours; heat it to 1160℃ for the second time, heat it up for 5 hours and keep it warm for 24 hours; heat it to 1195℃ for the third time, heat it up for 3 hours and keep it warm for 72 hours; cool it down to 1120℃, cool it down for 6 hours and keep it warm for 10 hours; cool it down to 550℃ for 10 hours and air cool it out of the furnace.

[0094] Then heat and forge again:

[0095] Place the vacuum induction electrode in a furnace at ≤300℃, heat it to 900±10℃, keep it warm for 3 hours, and heat it up at a rate of ≤100℃ / h; further heat it to 1080℃, heat it up for 2 hours, heat it up for 2 hours, and keep it warm for 3.5-4 hours;

[0096] Forging treatment is carried out, the starting forging temperature is 1050℃, the temperature in the blanking stage is 1095℃, the temperature in the later stage of forging is controlled at 1030℃, and the final forging temperature is ≥880℃.

[0097] Embodiment 2:

[0098] This embodiment provides a high-strength, high-hardness high-temperature alloy and a preparation method thereof. The high-strength, high-hardness high-temperature alloy includes the following components in mass fraction:

[0099] C: 0.02%, Cr: 17.5%, Al: 1.6%, Co: 4.0%, Ti: 0.75%, Nb: 5.6%, and the balance is Ni.

[0100] The preparation method comprises the following steps:

[0101] S1: Vacuum induction smelting and pouring:

[0102] Raw material ratio and furnace charging: according to the ratio of the alloy components, the raw materials are loaded into the vacuum induction furnace layer by layer. First add the main raw materials such as Ni and Cr, and then add the carburizer and other trace elements.

[0103] Smelting conditions: complete preheating and raw material melting under a vacuum degree of ≤50Pa; control the vacuum degree during melting to ≤20Pa, and perform refining after full melting; control the temperature during refining to 1570℃, the time ≥60min, maintain the vacuum degree ≤1.0Pa during refining, and in the vacuum induction furnace smelting process, start melting the materials at a vacuum induction furnace below ≤50Pa, remove metal chromium, aluminum, and titanium alloy, and add metal chromium after the nitrogen content of the fully melted materials is ≤50ppm. After all materials are melted, the vacuum induction furnace is kept at ≤1.0Pa for refining for 60min, and metal aluminum and titanium are added when the oxygen content and nitrogen content are both lower than 30PPM.

[0104] Casting conditions: Pour the molten steel into a steel ingot mold preheated to 800°C, and control the casting temperature to 1520°C to obtain a steel ingot.

[0105] S2: Heating forging and heat treatment:

[0106] Heating forging:

[0107] Homogenization treatment:

[0108] The steel ingot is heated to 1120°C at a heating rate of ≤150°C / h and kept at this temperature for 30 hours; the temperature is further raised to 1160°C and kept at this temperature for 30 hours; the temperature is again raised to 1200°C and kept at this temperature for 72 hours.

[0109] Forging stage: the steel ingot after homogenization treatment is cooled to 1080℃, kept warm for 3-4 hours and then taken out of the furnace for forging; the forging starting temperature is 1000℃, and the final forging temperature is ≥900℃.

[0110] Solution treatment:

[0111] The forged steel billet is loaded into the furnace, and the loading temperature is controlled to be ≤300°C; the heating rate is controlled to be ≤100°C / h, the temperature of the steel billet is raised to 890°C, and kept at this temperature for 1.5 hours; the temperature is raised to 970°C again, and the heating time is 2 hours. The holding time is calculated according to the formula a×d+t, where a is 1.5, d is the diameter of the steel billet (in mm), and t is 5; and then water-cooled.

[0112] Aging treatment:

[0113] The solution treated steel billet is loaded into the furnace, and the loading temperature is controlled to be ≤300°C; the temperature is raised to 710°C and kept at this temperature for 10 hours; the temperature is lowered to 610°C at a rate of 30°C / h, and kept at this temperature for 18 hours, and then the billet is air-cooled after being taken out of the furnace.

[0114] S3: Reheating, forging and homogenization treatment:

[0115] After the steel ingot obtained in step S2 is polished, vacuum consumable remelting is performed: vacuum consumable remelting is performed under a vacuum condition of ≤0.1 Pa, a droplet-controlled short arc melting method is adopted, and the melting rate is controlled to be 3 kg / min.

[0116] Then homogenize:

[0117] Control the charging temperature of the furnace at 700℃ and then load the furnace, heat it to 750℃ and keep it warm for 10 hours; heat it to 1110℃ for the first time, heat it up for 10 hours and keep it warm for 30 hours; heat it to 1150℃ for the second time, heat it up for 5 hours and keep it warm for 24 hours; heat it to 1185℃ for the third time, heat it up for 3 hours and keep it warm for 72 hours; cool it down to 1110℃, cool it down for 6 hours and keep it warm for 10 hours; cool it down to 540℃ for 10 hours and air cool it out of the furnace.

[0118] Then heat and forge again:

[0119] The vacuum induction electrode is charged into a furnace at ≤300°C, heated to 900°C, kept warm for 3 hours, and the heating rate is ≤100°C / h; further heated to 1070°C, the heating time is 2 hours, the heating time is 2 hours, and kept warm for 3.5 hours; forging treatment is carried out, the starting forging temperature is 1050°C, the temperature in the blanking stage is 1080°C, the temperature in the later forging stage is controlled at 1010°C, and the final forging temperature is ≥880°C.

[0120] Embodiment 3:

[0121] This embodiment provides a high-strength, high-hardness high-temperature alloy and a preparation method thereof. The high-strength, high-hardness high-temperature alloy includes the following components in mass fraction:

[0122] C: 0.05%, Si: 0.1%, Mn: 0.1%, S: 0.015%, P: 0.015%, Cr: 18.5%, Fe: 10.0%, Mo: 3.20%, Co: 4.5%, Al: 1.8%, Ti: 1.15%, Nb: 5.80%, B: 0.006%, Mg: 0.01%, the impurity components include: Cu: 0-0.1%, Ca: 0-0.005%, Bi: 0-0.00003%, Sn: 0-0.005%, Pb: 0-0.0005%, Ag: 0-0.0005%, Se: 0-0.0003%, Te: 0-0.00005%, Tl: 0-0.0001%, H: 0-5ppm, O: 0-50ppm, N: 0-50ppm, and the balance is Ni. The preparation method comprises the following steps:

[0123] S1: Vacuum induction smelting and pouring:

[0124] Raw material ratio and furnace charging: according to the ratio of the alloy components, the raw materials are loaded into the vacuum induction furnace layer by layer. First add the main raw materials such as Ni, Cr, Mo, and then add the carburizer and other trace elements.

[0125] Smelting conditions: complete preheating and raw material melting under a vacuum degree of ≤50Pa; control the vacuum degree during melting to ≤20Pa, and perform refining after full melting; control the temperature during refining to 1590℃, the time ≥60min, maintain the vacuum degree ≤1.0Pa during refining, and in the vacuum induction furnace smelting process, start melting the materials at a vacuum induction furnace below ≤50Pa, remove metal chromium, aluminum, and titanium alloy, and add metal chromium after the nitrogen content of the fully melted materials is ≤50ppm. After all materials are melted, the vacuum induction furnace is kept at ≤1.0Pa for 90min for refining, and metal aluminum and titanium are added when the oxygen content and nitrogen content are both lower than 30PPM.

[0126] Casting conditions: Pour the molten steel into a steel ingot mold preheated to 800°C, and control the casting temperature to 1530±10°C to obtain a steel ingot.

[0127] S2: Heating forging and heat treatment:

[0128] Heating forging:

[0129] Homogenization treatment:

[0130] The steel ingot is heated to 1120°C at a heating rate of ≤150°C / h and kept at this temperature for 30 hours; the temperature is further raised to 1160°C and kept at this temperature for 30 hours; the temperature is again raised to 1200°C and kept at this temperature for 72 hours.

[0131] Forging stage: the steel ingot after homogenization treatment is cooled to 1110℃, kept at this temperature for 4 hours and then taken out of the furnace for forging; the forging starting temperature is 1050℃ and the final forging temperature is ≥900℃.

[0132] Solution treatment:

[0133] The forged steel billet is loaded into the furnace, and the loading temperature is controlled to be ≤300°C; the heating rate is controlled to be ≤100°C / h, the temperature of the steel billet is raised to 910°C, and kept at this temperature for 1.5 hours; the temperature is raised to 990°C again, and the heating time is 2 hours. The holding time is calculated according to the formula a×d+t, where a is 1.8, d is the diameter of the steel billet (in mm), and t is 10; and then water-cooled.

[0134] Aging treatment:

[0135] Load the solution treated steel billet into the furnace and control the furnace temperature to ≤300℃;

[0136] Heat up to 730℃ and keep it for 10 hours; cool down to 630℃ at a rate of 30-50℃ / h, keep it for 18 hours, and then air cool it out of the furnace.

[0137] S3: Reheating, forging and homogenization treatment:

[0138] After the steel ingot obtained in step S2 is polished, vacuum consumable remelting is performed: vacuum consumable remelting is performed under a vacuum condition of ≤0.1 Pa, a droplet-controlled short arc melting method is adopted, and the melting rate is controlled to be 3 kg / min.

[0139] Then homogenize:

[0140] Control the charging temperature of the furnace at 700℃ and then load the furnace, heat it to 750℃ and keep it warm for 10 hours; heat it to 1130℃ for the first time, heat it up for 10 hours and keep it warm for 30 hours; heat it to 1170℃ for the second time, heat it up for 5 hours and keep it warm for 24 hours; heat it to 1205℃ for the third time, heat it up for 3 hours and keep it warm for 72 hours; cool it down to 1130℃, cool it down for 6 hours and keep it warm for 10 hours; cool it down to 560℃ for 10 hours and air cool it out of the furnace.

[0141] Then heat and forge again:

[0142] Place the vacuum induction electrode in a furnace at ≤300°C, heat it to 900±10°C, keep it warm for 3 hours, and heat it up at a rate of ≤100°C / h; then heat it up to 1090°C for 2 hours, heat it up for 2 hours, and keep it warm for 4 hours;

[0143] Forging treatment is carried out, the starting forging temperature is 1050℃, the temperature in the blanking stage is 1110℃, the temperature in the later stage of forging is controlled at 1050℃, and the final forging temperature is ≥880℃.

[0144] The high strength and high hardness high temperature alloy prepared in the above-mentioned embodiment 1 of the present invention was tested for mechanical properties, and the test standards and results are shown in the following table:

[0145] Table 2 Mechanical properties

[0146]

[0147] It can be seen from the above table that compared with the existing 718 alloy, the alloy prepared in the embodiment of the present invention has higher tensile strength, and the elongation after fracture and the cross-sectional shrinkage rate are slightly reduced, but both are higher than the standard values, and the main performance indicators hardness and tensile strength are higher. This further illustrates that the present invention obtains a high-temperature alloy with higher tensile strength and high hardness through the preparation method controlled by composition and process.

[0148] The metallographic examination of the high-strength, high-hardness and high-temperature alloys in the above-mentioned embodiments 1-3 of the present invention and those not mentioned in the present invention can meet the following standards:

[0149] 1) There are no visible metallurgical defects such as looseness, pinholes, cracks, shrinkage holes, segregation, slag inclusions, etc. on the transverse low-magnification specimen in the delivery state.

[0150] 2) The evaluation of purity carbides shall refer to GB / T 14999.5. The carbides shall be based on the most serious field of view on the test piece and rated according to the Class B spectrum. ≤Level 2 is qualified.

[0151] 3) The purity inclusion assessment refers to ASTM E45. The inclusion is based on the most serious field of view on the test piece. Class A and C are level 0, Class B is level 0.5, and Class D is level 1.5.

[0152] 4) Grain size rating refers to GB / T 14999.4 Class B (ASTM E112), the average grain size is 6.5, and there are no double grains.

[0153] The present invention provides a high-strength, high-hardness high-temperature alloy and a preparation method thereof, aiming to solve the problem of insufficient strength and hardness of high-temperature alloy materials in the prior art, especially unstable performance under high-temperature environment: existing high-temperature alloys, such as Inconel 718, although having good high-temperature resistance, have relatively low hardness and tensile strength, and cannot meet the higher requirements of certain high-end application fields for high hardness, strength and high-temperature fatigue resistance.

[0154] The core principle of the present invention is to optimize the composition ratio of the alloy, especially to increase the content of Al, Nb and Co elements, strengthen the amount of γ′ and γ″ phases in the alloy, thereby improving the effect of solid solution strengthening and aging strengthening. This improvement significantly improves the hardness and strength of the alloy material. In particular, by adjusting the content of elements such as aluminum and molybdenum in the alloy, not only the deformation resistance at high temperature is optimized, but also the strength and corrosion resistance at high temperature are improved. In view of the problem of poor hot working plasticity of traditional high-temperature alloys, the present invention effectively improves the processability and final mechanical properties of the material through innovative homogenization treatment, forging heating process and reasonable solid solution and aging heat treatment methods.

[0155] The preparation method of the present invention includes precise vacuum induction smelting, vacuum consumable remelting, homogenization treatment and advanced forging and heat treatment processes, which make the composition of the alloy more uniform, reduce the anisotropy of the material, and enhance its comprehensive performance. At the same time, the use of efficient atmosphere control and low-temperature heating forging processes not only improves the mechanical properties of the alloy, but also ensures the high-temperature performance and long-term stability of the material. Through the preparation method and alloy of the present invention, the deficiencies of existing high-temperature alloy materials in high strength, high hardness and high-temperature durability are solved, and a high-performance material that is more suitable for aviation, aerospace, high-end precision instruments and other fields is provided, which has broad application prospects.

[0156] In the description of the present application, the description with reference to the terms "one embodiment", "some embodiments", "in the present embodiment", "specific example", or "some examples" etc. means that the specific features, mechanisms, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, mechanisms, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0157] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A high-strength, high-hardness high-temperature alloy, characterized in that: Its ingredients by weight percentage include: C: 0.02-0.05%, Si: 0-0.1%, Mn: 0-0.1%, S: 0-0.015%, P: 0-0.015%, Cr: 17.5-18.5%, Fe: 0-10.0%, Al: 1.6-1.8%, Co: 4.0-4.5%, Ti: 0.75-1.15%, Nb: 5.6-5.8%, B: 0-0.006%, Mg: 0-0.01%, and the balance is Ni and unavoidable impurities.

2. The high-strength, high-hardness high-temperature alloy according to claim 1, characterized in that: Its components by weight percentage include: C: 0.025-0.035%, Si: 0-0.08%, Mn: 0-0.05%, S: 0-0.010%, P: 0-0.010%, Cr: 17.7-18.0%, Fe: 0-9.0%, Mo: 2.80-3.20%, Co: 4.20-4.40%, Al: 1.70-1.90%, Ti: 0.95-1.10%, Nb: 5.60-5.80%, B: 0.003-0.006%, Mg: 0-0.010%, Ni: 56.50-58.50%, the impurity components include: Cu: 0-0.1%, Ca: 0-0.005%, Bi: 0-0.00003%, Sn: 0-0.005%, Pb: 0-0.0005%, Ag: 0-0.0005%, Se: 0-0.0003%, Te: 0-0.00005%, Tl: 0-0.0001%, H: 0-5ppm, O: 0-50ppm, N: 0-50ppm.

3. A method for preparing the high-strength, high-hardness high-temperature alloy according to any one of claims 1 to 2, characterized in that: The following steps are involved: S1: Mix the raw materials according to the composition ratio of the high-strength, high-hardness high-temperature alloy, perform vacuum induction smelting, then pour molten steel and vacuum consumable remelting to obtain a steel ingot, wherein the refining temperature of the vacuum induction smelting is 1580±10°C, and the refining time is ≥60min; S2: subjecting the steel ingot obtained in step S1 to heating forging, solution treatment and aging treatment to obtain a vacuum induction electrode; S3: The vacuum induction electrode obtained in step S2 is subjected to lathing, vacuum consumable remelting, homogenization treatment and reheating and forging treatment to obtain a high-strength, high-hardness high-temperature alloy, wherein the melting rate of the vacuum consumable remelting is 3 kg / min.

4. The method for preparing the high-strength, high-hardness high-temperature alloy according to claim 3, characterized in that: In step S1, the conditions of vacuum induction smelting are: the vacuum degree in the preheating period is controlled at ≤50Pa, the vacuum degree in the raw material melting period is controlled at ≤20Pa, and the vacuum degree in the refining period is ≤1.0Pa.

5. The method for preparing the high-strength, high-hardness high-temperature alloy according to claim 3, characterized in that: In the step S1, the temperature of the poured molten steel is 1530±10°C.

6. The method for preparing the high-strength, high-hardness high-temperature alloy according to claim 3, characterized in that: In step S2, the heating forging conditions are as follows: heating the steel ingot to 1120°C at a heating rate of ≤150°C / h and keeping it warm for 30 hours; then continuing to heat it to 1160°C and keeping it warm for 30 hours; heating it again to 1200°C and keeping it warm for 72 hours for homogenization heat treatment, then cooling it to 1080-1110°C and keeping it warm for 3-4 hours, and then taking it out of the furnace for forging. During the forging, the start forging temperature is 1000-1050°C, and the final forging temperature is ≥900°C.

7. The method for preparing the high-strength, high-hardness high-temperature alloy according to claim 3, characterized in that: In the step S2, the conditions of the solution treatment are: controlling the charging temperature to be less than or equal to 300°C, charging the steel ingot into the furnace, controlling the heating rate to be ≤100°C / h, raising the temperature of the steel ingot to 900°C±10°C and keeping it warm for 1.5h; then heating the temperature of the steel ingot for 2 hours to further raise it to 980°C±10°C, keeping it warm for a×d+t min, where a is 1.5-1.8, d is the diameter of the steel billet in mm, and t is 5-10; water cooling treatment; the conditions of the aging treatment are: controlling the charging temperature to be less than or equal to 300°C, charging the steel ingot into the furnace, controlling the heating rate to be ≤100°C / h, raising the temperature of the steel ingot to 720±10°C and keeping it warm for 10h; then cooling the temperature to 620±10°C at a cooling rate of 30-50°C / h and keeping it warm for 18h, and air cooling treatment after taking it out of the furnace.

8. The method for preparing the high-strength, high-hardness high-temperature alloy according to claim 3, characterized in that: In the step S3, the vacuum degree of the vacuum consumable remelting is less than 0.1 Pa, and the vacuum consumable remelting adopts droplet-controlled short arc melting.

9. The method for preparing a high-strength, high-hardness high-temperature alloy according to claim 3, characterized in that: In step S3, the conditions for the homogenization treatment are: The charging temperature of the consumable steel ingot is controlled to be 700℃ before loading, and the temperature in the furnace is controlled to rise to 750℃ and kept at this temperature for 10 hours; Carry out the first heating, raise the temperature to 1120±10℃, the heating time is 10 hours, and the first heat preservation is 30 hours; Carry out the second heating, raise the temperature to 1160±10℃, the heating time is 5 hours, and the second heating is kept for 24 hours; The third heating is carried out to raise the temperature to 1195±10°C for 3 hours and the third heating is kept for 72 hours; The first cooling is performed to reduce the temperature to 1120±10℃ for 6 hours, and the fourth heating is performed for 10 hours; The temperature was lowered to 550±10℃ for 10 hours and then air-cooled.

10. The method for preparing a high-strength, high-hardness high-temperature alloy according to claim 3, characterized in that: In step S3, the conditions for the reheating forging treatment are: the vacuum induction electrode is charged into the furnace at a temperature of ≤300°C, and the temperature is increased to 900°C±10°C at a heating rate of not more than 100°C / h, and the temperature is kept for 3 hours; the temperature is further increased to 1080°C±10°C, the heating time is 2 hours, and the temperature is kept for 3.5 to 4 hours; the start forging temperature of the forging is 1050°C, Forging is performed, and the forging temperature in the blanking stage is 1080-1110°C, and the temperature in the later stage of forging is 1010-1050°C. Final calcination temperature ≥880℃.

Images