A nickel-based corrosion-resistant alloy and its preparation method

Abstract

The present invention discloses a nickel-based corrosion-resistant alloy and a preparation method thereof, which relates to the technical field of alloy preparation. The nickel-based corrosion-resistant alloy comprises the following elements in weight percentages: Cr: 22-25 wt%; Mo: 8-10 wt%; Fe: 1-3 wt%; Cu: 1.8-3.5 wt%; Al: 0.5-1.2 wt%; Ti: 0.3-0.8 wt%; W: 1.5-3.5 wt%; B: 0.002-0.01 wt%; Y: 0.02-0.12 wt%; Ce: 0.02-0.07 wt%; and Ni: the balance. The present invention has the effect of improving the corrosion resistance of the nickel-based alloy by combining multi-element alloying and a fine preparation process.

Description

Technical Field

[0001] The present invention relates to the technical field of alloy preparation, and particularly to a nickel-based corrosion-resistant alloy and a preparation method thereof. Background Art

[0002] Although traditional nickel-based alloys have good corrosion resistance and high-temperature performance, their performance still needs to be improved in some extreme environments, such as high salinity, high acidity or high-temperature atmospheres. Especially in the fields of petrochemical industry, ocean engineering and nuclear reactors, the corrosion resistance and high-temperature performance of materials are particularly critical. Therefore, it is necessary to develop a new type of nickel-based alloy to meet the application requirements under these harsh environments. Summary of the Invention

[0003] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a nickel-based corrosion-resistant alloy and a preparation method thereof.

[0004] The above object of the present invention is achieved by the following technical solutions:

[0005] A nickel-based corrosion-resistant alloy, comprising the following elements in weight percentages:

[0006] Cr: 22 - 25 wt%;

[0007] Mo: 8 - 10 wt%;

[0008] Fe: 1 - 3 wt%;

[0009] Cu: 1.8 - 3.5 wt%;

[0010] Al: 0.5 - 1.2 wt%;

[0011] Ti: 0.3 - 0.8 wt%;

[0012] W: 1.5 - 3.5 wt%;

[0013] B: 0.002 - 0.01 wt%;

[0014] Y: 0.02 - 0.12 wt%;

[0015] Ce: 0.02 - 0.07 wt%;

[0016] Ni: the balance.

[0017] In the alloy of the present invention, 22 - 25 wt% of chromium (Cr) and 8 - 10 wt% of molybdenum (Mo) are added to form a stable passivation film, which can effectively improve the corrosion resistance of the alloy in a high-temperature oxidizing environment. The addition of molybdenum can particularly enhance the resistance to pitting and crevice corrosion, and is suitable for harsh working conditions in acidic media and high-temperature atmospheres. In addition, the synergistic effect of chromium and molybdenum can reduce the defects of the oxide film and improve the stability of high-temperature corrosion resistance. The addition of a small amount of tungsten (W, 1.5 - 3.5 wt%) further enhances the chemical stability of the alloy in high-temperature oxidation and corrosion environments. The rare earth elements yttrium (Y, 0.02 - 0.12 wt%) and cerium (Ce, 0.02 - 0.07 wt%) optimize the structure of the oxide film of the alloy and enhance its antioxidant ability in high-temperature environments.

[0018] Adding 1.8 - 3.5 wt% of copper (Cu) significantly improves the alloy's resistance to chloride ion corrosion. Copper can inhibit the diffusion of chloride ions and the occurrence of local corrosion, especially showing excellent stress corrosion cracking resistance in marine or chloride-containing corrosive environments. At the same time, the synergistic effect of molybdenum and tungsten improves the corrosion resistance of the alloy in chloride-containing acidic media and extends its service life in harsh environments.

[0019] By introducing 0.5 - 1.2 wt% of aluminum (Al) and 0.3 - 0.8 wt% of titanium (Ti), precipitation strengthening phases (such as γ' or Ni3(Al,Ti)) are formed in the alloy, significantly improving the strength and hardness of the material while maintaining good toughness. An appropriate amount of iron (Fe, 1 - 3 wt%) improves the plasticity and impact resistance while maintaining the high strength of the alloy, ensuring the reliability of the material under harsh conditions.

[0020] The addition of trace boron (B, 0.002 - 0.01 wt%) increases the grain boundary strength of the alloy, reducing stress concentration and corrosion risk at the grain boundaries. The rare earth elements yttrium and cerium can refine the grains and enhance the grain boundary stability, thereby improving the high-temperature creep resistance and fatigue resistance of the material.

[0021] Furthermore, it also includes niobium element, and the weight percentage of the niobium element is 0.8 - 1.8 wt%.

[0022] The introduction of niobium can jointly form stable Ni3(Al,Ti,Nb) precipitation phases with aluminum and titanium, further enhancing the strength and hardness of the alloy. At the same time, the thermal stability of this precipitation phase enables the material to maintain excellent mechanical properties under high-temperature conditions, making it particularly suitable for high-temperature equipment and structural components. Niobium can effectively inhibit the slip and propagation of grain boundaries, reduce creep deformation in high-temperature environments, and thus increase the high-temperature service life of the alloy. This improvement is particularly important for workpieces that are long-term exposed to high-temperature and high-stress environments. The micro-segregation of niobium at grain boundaries can inhibit the corrosion sensitivity of grain boundary precipitates, further enhancing the corrosion resistance of the alloy in acidic media. At the same time, the combined action of niobium with molybdenum and tungsten enhances the resistance to pitting and crevice corrosion, making the alloy perform better in chloride-containing environments.

[0023] Further, the weight percentage of the molybdenum element is 9 - 10 wt%; the weight percentage of the tungsten element is 3 - 3.5 wt%.

[0024] Higher content of molybdenum (9 - 10 wt%) further enhances the resistance to pitting and crevice corrosion, making the alloy perform better in strongly acidic and chloride-containing environments. The high molybdenum content can also enhance the stability of the passive film and reduce the risk of local corrosion. The increase in tungsten content (3 - 3.5 wt%) significantly enhances the strength of the alloy under high-temperature conditions. The high melting point and strengthening effect of tungsten enable the material to withstand higher mechanical stresses in high-temperature environments, making it particularly suitable for high-temperature and high-pressure working conditions.

[0025] Further, the weight percentage of the yttrium element is 0.08 - 0.12 wt%; the weight percentage of the cerium element is 0.05 - 0.07 wt%.

[0026] Higher contents of yttrium and cerium can further improve the compactness and uniformity of the oxide film, significantly enhancing the corrosion resistance of the alloy in high-temperature oxidation environments. These rare earth elements reduce the risk of oxide spalling by inhibiting the crack propagation of the oxide film. Yttrium and cerium can refine grains and form a stabilizing effect at grain boundaries, reducing the corrosion sensitivity caused by grain boundary precipitates, and are particularly suitable for long-term use scenarios in high-temperature corrosive media.

[0027] Further, it also includes zirconium element, and the weight percentage of the zirconium element is 0.01 - 0.1 wt%.

[0028] Zirconium can effectively reduce the tendency of grain boundary precipitate formation, inhibit the sensitivity of grain boundary corrosion, while enhancing the bonding strength of grain boundaries and improving the service reliability of alloys in harsh environments. The addition of zirconium optimizes the structure of the oxidation-resistant film of the alloy, further enhancing the stability and durability of the material in high-temperature oxidation environments. The addition of trace zirconium significantly extends the fatigue life of the material in high-temperature and high-stress environments while maintaining excellent corrosion resistance, making it suitable for critical equipment components under extreme conditions.

[0029] A preparation method of a nickel-based corrosion-resistant alloy, comprising the following steps:

[0030] S1: Precision melting step;

[0031] The precision melting step includes three steps: vacuum induction melting of raw materials, vacuum arc remelting, and precise furnace cooling control;

[0032] S2: Directional solidification control step;

[0033] The directional solidification control step includes a heating stage, a first cooling and solidification stage, and a second cooling and solidification stage, and the cooling rate in the first cooling and solidification stage is lower than that in the second cooling and solidification stage;

[0034] S3: Variable-temperature multi-stage heat treatment step;

[0035] The variable-temperature multi-stage heat treatment step includes solution treatment, a first aging treatment stage, and a second aging treatment stage.

[0036] Through the above preparation method, the process design of vacuum induction melting combined with vacuum arc remelting ensures the uniformity and purity of the alloy composition. The directional solidification control step forms a columnar crystal structure through staged cooling and solidification, significantly improving the creep resistance and mechanical properties of the alloy. The variable-temperature multi-stage heat treatment optimizes the structure and properties of the alloy through solution treatment and two-stage aging treatment, thus realizing the optimization of the alloy structure and the improvement of properties.

[0037] Furthermore, the specific operation of the S1 precision melting step is as follows:

[0038] S1.1 Vacuum induction melting of raw materials: ① At 1400 - 1450 °C, while maintaining 10 -2Pre-melt the Ni matrix under low-pressure argon gas of Pa; ② After the Ni matrix is completely melted, raise the melting temperature to 1500 - 1550 °C, and add chromium, molybdenum, tungsten, and niobium elements in order from high melting point to low melting point; ③ After the elements are fully melted, add iron and copper elements at a temperature of 1550 °C; ④ After the elements are fully melted, lower the melting temperature to 1500 - 1520 °C, and add aluminum and titanium elements; ⑤ After it is completely melted, control the melting temperature to 1400 - 1450 °C, and then add yttrium, cerium, zirconium, and boron elements; ⑥ After it is completely melted, control the melting temperature at 1500 - 1550 °C, hold for 10 min, cool slowly at 3 - 5 °C / min to 1400 °C and then cool rapidly at 20 - 30 °C / min to 500 - 600 °C;

[0039] S1.2 Vacuum arc remelting: Carry out vacuum arc remelting on the ingot obtained by vacuum induction melting under the conditions of controlling the melting current at 6 - 8 kA, the melting speed at 10 - 15 mm / min, and the vacuum degree at 0.5 - 1 Pa to obtain a remelted ingot, and directly transfer the remelted ingot to furnace cooling at a temperature higher than 1000 °C;

[0040] S1.3 Furnace cooling control: Slowly cool the remelted ingot at 2 - 5 °C / min to 1000 °C first; then rapidly cool it at 20 - 30 °C / min to 500 °C.

[0041] The preferential addition of high melting point elements such as chromium, molybdenum, tungsten, and niobium, combined with strict temperature control (1500 - 1550 °C), ensures the complete melting of these elements and reduces microsegregation. Especially, tungsten and molybdenum are prone to form complex intermediate phases at high temperatures. If the temperature is insufficient or the addition sequence is improper, it may lead to the stabilization of these intermediate phases, thus affecting the performance of the alloy. The subsequent addition of rare earth elements (yttrium, cerium) and zirconium and boron significantly enhances the grain refinement effect through reactions with the molten metal matrix. Among them, yttrium and cerium help to capture impurities and oxides, while zirconium and boron further optimize the high-temperature performance and oxidation resistance by forming composite phases with the iron matrix.

[0042] The vacuum arc remelting step effectively eliminates the macrosegregation in the previous step, reduces the number of inclusions, and refines the grain structure by precisely controlling the melting current (6 - 8 kA) and melting speed (10 - 15 mm / min). The uniform structure formed during the remelting process provides a basis for the stable growth of columnar crystals in the directional solidification step. The combination of the arc energy input during remelting and the stability of the molten pool enables the ingot to form a denser structure, especially in the distribution of high melting point elements (such as molybdenum and tungsten), which has been significantly improved. The furnace cooling control after melting (slow cooling at 2 - 5 °C / min to 1000 °C, rapid cooling at 20 - 30 °C / min to 500 °C) further optimizes the distribution of molybdenum, tungsten, and rare earth elements in the matrix and avoids the premature formation of precipitation phases.

[0043] The precise temperature control strategy in the furnace cooling stage (slow cooling at 2 - 5 °C / min to 1000 °C, and then rapid cooling at 20 - 30 °C / min to 500 °C) further highlights its importance. The main function of the slow cooling stage is to eliminate the thermal stress in the crystal, and at the same time, enable the high melting point elements (such as molybdenum and tungsten) to gradually diffuse into the alloy matrix to form a uniform distribution. Rapid cooling inhibits the formation of low-temperature precipitation phases, and at the same time locks in the synergistic strengthening effect between rare earth elements and the matrix, ensuring both high-temperature strength and low-temperature toughness. In addition, the presence of rare earth elements can passivate grain boundaries, reduce grain boundary oxidation, and thus further improve the creep resistance of the material.

[0044] Furthermore, the specific operation of the S2 directional solidification control step is as follows:

[0045] S2.1 Heating stage: Heat the ingot from 500 °C to 1500 - 1550 °C at a rate of 3 - 5 °C / min;

[0046] S2.2 First cooling and solidification stage: Cool the ingot at a low speed of 2 - 5 °C / min to 1200 °C, and draw the ingot at a speed of 0.1 - 1 mm / min;

[0047] S2.3 Second cooling and solidification stage: Cool the ingot at a rapid rate of 20 - 30 °C / min to 800 °C.

[0048] By heating to 1500 - 1550 °C at a rate of 3 - 5 °C / min, the accumulation of thermal stress caused by excessive temperature gradient inside the ingot can be avoided, ensuring a uniform temperature distribution and creating a uniform molten pool environment for subsequent directional solidification. The high-temperature heating stage remelts the possible initial precipitation phases (such as brittle compounds) on the grain boundaries, laying the foundation for the stable growth of columnar crystals during the directional solidification process.

[0049] At a low cooling rate, the solute diffusion in the liquid metal is fully adjusted, which is beneficial to the growth of columnar crystals along the direction of directional drawing, and at the same time reduces the chemical composition segregation between dendrites. Controlling the drawing speed at 0.1 - 1 mm / min can promote the preferred orientation growth of grains, avoid the formation of equiaxed crystals, and thus improve the high-temperature creep resistance and grain boundary strength of the material.

[0050] Rapid cooling inhibits the non-uniform precipitation of the second phase by compressing the diffusion rate of elements at the grain boundaries. At the same time, it retains the structure in the high-temperature solid solution state, reduces the formation of brittle precipitates near the grain boundaries, and further optimizes the efficiency of subsequent heat treatment.

[0051] Furthermore, the specific operation of the S3 variable-temperature multi-stage heat treatment step is as follows:

[0052] S3.1 Solution treatment: Heat the ingot at a rate of 3 - 5 °C / min to 1120 - 1160 °C, hold for 2 - 4 hours, and immediately perform oil quenching for rapid cooling;

[0053] S3.2 The first aging treatment stage: Heat the ingot at a rate of 3 - 5 °C / min to 850 - 900 °C, hold for 8 - 12 hours, and then cool to room temperature at a rate of 5 - 10 °C / min;

[0054] S3.3 The second aging treatment stage: Heat the ingot at a rate of 3 - 5 °C / min to 700 - 750 °C, hold for 6 - 10 hours, and then cool to room temperature at a rate of 5 - 10 °C / min.

[0055] At a high temperature of 1120 - 1160 °C, carbides and other low - temperature precipitation phases (such as Laves phase or σ phase) can be fully dissolved, greatly improving the chemical homogeneity of the matrix. This process reduces the micro - segregation problem inside the material, providing a uniform elemental distribution basis for subsequent aging treatment.

[0056] Hold at a high temperature of 1120 - 1160 °C for 2 - 4 hours to fully dissolve carbides and other low - temperature precipitation phases, optimize the matrix uniformity, and create ideal conditions for aging treatment. Rapid oil quenching avoids the re - formation of precipitates at high temperatures. By holding at 850 - 900 °C for a long time (8 - 12 hours), the γ′ phase is fully precipitated, significantly improving the high - temperature strength and creep resistance of the alloy. By holding at 700 - 750 °C (6 - 10 hours), the morphology of the precipitation phase is optimized, further improving the toughness and fatigue resistance, making the material have more balanced mechanical properties. Slowly cooling to room temperature ensures the release of thermal stress and tissue stability.

[0057] Compared with the prior art, the beneficial effects of the present invention are mainly reflected in the following aspects:

[0058] 1. The nickel - based alloy of the present invention, through the combination of carefully designed alloy compositions (such as the addition of molybdenum, tungsten, niobium, and rare - earth elements yttrium and cerium) and processes, forms an optimized passivation film and microstructure, significantly improving the corrosion resistance and durability in high - temperature and corrosive environments. This characteristic makes the alloy particularly suitable for harsh environments such as marine, petrochemical, and nuclear energy. The copper element in the alloy significantly improves the ability to resist chloride ion corrosion, and the synergistic effect of chromium and molybdenum further enhances the stability of the alloy in acidic and chloride - containing environments. This synergistic effect between elements makes the nickel - based alloy of the present invention exhibit excellent performance in various corrosive environments.

[0059] 2. Through precise melting and directional solidification techniques, the crystal growth and the formation of precipitation phases are precisely controlled during the alloy preparation process, thereby optimizing the high-temperature strength and creep resistance of the material. This innovation in the process ensures the stability and reliability of the material in long-term high-temperature applications.

[0060] 3. Through reasonable element ratios and preparation processes, the high-temperature strength and low-temperature toughness in the alloy are simultaneously optimized. In particular, the high content of molybdenum and tungsten combined with the use of copper and niobium significantly improves the pitting and crevice corrosion resistance of the alloy, making the alloy perform excellently in corrosive environments containing chlorine, etc. Detailed implementation manners

[0061] The present invention will be described in detail below in conjunction with embodiments.

[0062] Embodiment 1

[0063] Embodiment 1 discloses a preparation method of a nickel-based corrosion-resistant alloy, and the raw materials are configured as follows by weight percentage:

[0064] Chromium (Cr): 23.5 wt%

[0065] Molybdenum (Mo): 8.5 wt%

[0066] Iron (Fe): 2.5 wt%

[0067] Copper (Cu): 3.0 wt%

[0068] Aluminum (Al): 0.8 wt%

[0069] Titanium (Ti): 0.5 wt%

[0070] Tungsten (W): 2.5 wt%

[0071] Boron (B): 0.005 wt%

[0072] Yttrium (Y): 0.05 wt%

[0073] Cerium (Ce): 0.04 wt%

[0074] Nickel (Ni): the balance

[0075] The preparation steps are as follows:

[0076] S1: Precise melting step

[0077] S1.1 Vacuum induction melting of raw materials:

[0078] ① Pre-melt the Ni matrix in a low-pressure argon environment of 1400 °C and 10 -2 Pa

[0079] ② After the Ni matrix is completely melted, raise the melting temperature to 1550 °C, and successively add chromium, molybdenum, and tungsten elements, and stir until fully dissolved;

[0080] ③ At 1550 °C, add iron and copper, and continue to stir until fully dissolved;

[0081] ④ Lower the melting temperature to 1520 °C, add aluminum and titanium elements, and stir evenly;

[0082] ⑤ Lower the temperature to 1450 °C, and add yttrium, cerium, and boron elements;

[0083] ⑥ Control the melting temperature to 1550 °C, keep it warm for 10 minutes, then cool it to 1400 °C at a rate of 5 °C / min, and then quickly cool it to 600 °C at a rate of 30 °C / min.

[0084] S1.2 Vacuum arc remelting:

[0085] Place the ingot obtained by vacuum induction melting in a vacuum arc furnace with the following conditions: the melting current is 7 kA, the melting speed is 12 mm / min, and the vacuum degree is 0.8 Pa. The remelted ingot is directly transferred to furnace cooling under the condition of higher than 1000 °C.

[0086] S1.3 Furnace cooling control:

[0087] The remelted ingot is slowly cooled to 1000 °C at a rate of 2 °C / min, and then quickly cooled to 500 °C at a rate of 30 °C / min.

[0088] S2: Directional solidification control steps

[0089] S2.1 Heating stage:

[0090] Heat the ingot from 500 °C to 1520 °C at a rate of 3 °C / min.

[0091] S2.2 First cooling and solidification stage:

[0092] Cool the ingot to 1200 °C at a rate of 2 °C / min, and draw the ingot at a rate of 0.5 mm / min to control the cooling and crystallization evenly.

[0093] S2.3 Second cooling and solidification stage:

[0094] Quickly cool the ingot to 800 °C at a rate of 25 °C / min.

[0095] S3: Variable temperature multi-stage heat treatment steps

[0096] S3.1 Solution treatment:

[0097] Heat the ingot to 1140 °C at a rate of 4 °C / min, keep it warm for 3 hours, and then perform oil quenching immediately.

[0098] S3.2 First aging treatment stage:

[0099] The ingot is heated to 875 °C at a rate of 4 °C / min, held for 10 hours, and then cooled to room temperature at a rate of 7 °C / min.

[0100] S3.3 Second aging treatment stage:

[0101] The ingot is heated to 725 °C at a rate of 4 °C / min, held for 8 hours, and then cooled to room temperature at a rate of 7 °C / min.

[0102] Example 2

[0103] Example 2 discloses a preparation method of a nickel-based corrosion-resistant alloy, and the raw materials are configured as follows by weight percentage:

[0104] Chromium (Cr): 23.5 wt%;

[0105] Molybdenum (Mo): 9.5 wt%;

[0106] Iron (Fe): 2.5 wt%;

[0107] Copper (Cu): 3.0 wt%;

[0108] Aluminum (Al): 0.8 wt%;

[0109] Titanium (Ti): 0.5 wt%;

[0110] Tungsten (W): 3.5 wt%;

[0111] Boron (B): 0.005 wt%;

[0112] Yttrium (Y): 0.05 wt%;

[0113] Cerium (Ce): 0.04 wt%;

[0114] Nickel (Ni): the balance.

[0115] The preparation steps are as follows:

[0116] S1: Precise melting step

[0117] S1.1 Vacuum induction melting of raw materials:

[0118] ① In a low-pressure argon environment of 1400 °C and 10 -2 Pa, pre-melt the Ni matrix;

[0119] ② After the Ni matrix is completely melted, raise the melting temperature to 1550 °C, and add chromium, molybdenum, and tungsten elements in sequence, and stir until fully dissolved;

[0120] ③ Add iron and copper at 1550 °C, and continue to stir until fully dissolved;

[0121] ④ Reduce the melting temperature to 1520°C, add aluminum and titanium elements, and stir evenly;

[0122] ⑤ Reduce the temperature to 1450°C, and add yttrium, cerium, and boron elements;

[0123] ⑥ Control the melting temperature to 1550°C, keep it warm for 10 minutes, then cool it to 1400°C at a rate of 5°C / min, and then quickly cool it to 600°C at a rate of 30°C / min.

[0124] S1.2 Vacuum arc remelting:

[0125] Place the ingot obtained by vacuum induction melting in a vacuum arc furnace with the following conditions: the melting current is 7 kA, the melting speed is 12 mm / min, and the vacuum degree is 0.8 Pa. The remelted ingot is directly transferred to furnace cooling under the condition of higher than 1000°C.

[0126] S1.3 Furnace cooling control:

[0127] The remelted ingot is slowly cooled to 1000°C at a rate of 2°C / min, and then quickly cooled to 500°C at a rate of 20°C / min.

[0128] S2: Directional solidification control steps

[0129] S2.1 Heating stage:

[0130] Heat the ingot from 500°C to 1520°C at a rate of 3°C / min.

[0131] S2.2 First cooling and solidification stage:

[0132] Cool the ingot to 1200°C at a rate of 2°C / min, and draw the ingot at a rate of 0.5 mm / min to control the cooling and crystallization evenly.

[0133] S2.3 Second cooling and solidification stage:

[0134] Quickly cool the ingot to 800°C at a rate of 25°C / min.

[0135] S3: Variable temperature multi-stage heat treatment steps

[0136] S3.1 Solution treatment:

[0137] Heat the ingot to 1140°C at a rate of 4°C / min, keep it warm for 3 hours, and then perform oil quenching immediately.

[0138] S3.2 First aging treatment stage:

[0139] Heat the ingot to 875°C at a rate of 4°C / min, keep it warm for 10 hours, and then cool it to room temperature at a rate of 7°C / min.

[0140] S3.3 Second aging treatment stage:

[0141] The ingot is heated to 725 °C at 4 °C / min, held for 8 hours, and then cooled to room temperature at 7 °C / min.

[0142] Example 3

[0143] Example 3 discloses a preparation method of a nickel-based corrosion-resistant alloy, and the raw materials are configured according to the following weight percentages:

[0144] Chromium (Cr): 23.5 wt%;

[0145] Molybdenum (Mo): 8.5 wt%;

[0146] Iron (Fe): 2.5 wt%;

[0147] Copper (Cu): 3.0 wt%;

[0148] Aluminum (Al): 0.8 wt%;

[0149] Titanium (Ti): 0.5 wt%;

[0150] Tungsten (W): 2.5 wt%;

[0151] Boron (B): 0.005 wt%;

[0152] Yttrium (Y): 0.1 wt%;

[0153] Cerium (Ce): 0.06 wt%;

[0154] Nickel (Ni): the balance.

[0155] The preparation steps are as follows:

[0156] S1: Precision melting step

[0157] S1.1 Vacuum induction melting of raw materials:

[0158] ① In a low-pressure argon environment of 1400 °C and 10 -2 Pa, pre-melt the Ni matrix;

[0159] ② After the Ni matrix is completely melted, raise the melting temperature to 1550 °C, and successively add chromium, molybdenum, and tungsten elements, and stir until fully dissolved;

[0160] ③ Add iron and copper at 1550 °C, and continue to stir until fully dissolved;

[0161] ④ Lower the melting temperature to 1520 °C, add aluminum and titanium elements, and stir evenly;

[0162] ⑤ Reduce the temperature to 1450 °C and add yttrium, cerium, and boron elements;

[0163] ⑥ Control the melting temperature to 1550 °C, hold for 10 minutes, then cool to 1400 °C at a rate of 3 °C / min, and then quickly cool to 600 °C at a rate of 30 °C / min.

[0164] S1.2 Vacuum arc remelting:

[0165] Place the ingot obtained by vacuum induction melting in a vacuum arc furnace with the following conditions: melting current is 7 kA, melting speed is 12 mm / min, and vacuum degree is 0.8 Pa. The remelted ingot is directly transferred to furnace cooling under the condition of higher than 1000 °C.

[0166] S1.3 Furnace cooling control:

[0167] The remelted ingot is slowly cooled to 1000 °C at a rate of 2 °C / min, and then quickly cooled to 500 °C at a rate of 30 °C / min.

[0168] S2: Directional solidification control step

[0169] S2.1 Heating stage:

[0170] Heat the ingot from 500 °C to 1520 °C at a rate of 3 °C / min.

[0171] S2.2 First cooling and solidification stage:

[0172] Cool the ingot to 1200 °C at a rate of 2 °C / min and draw the ingot at a rate of 0.5 mm / min to control the uniformity of cooling and crystallization.

[0173] S2.3 Second cooling and solidification stage:

[0174] Quickly cool the ingot to 800 °C at a rate of 25 °C / min.

[0175] S3: Variable temperature multi-stage heat treatment step

[0176] S3.1 Solution treatment:

[0177] Heat the ingot to 1140 °C at a rate of 4 °C / min, hold for 3 hours, and then immediately perform oil quenching.

[0178] S3.2 First aging treatment stage:

[0179] Heat the ingot to 875 °C at a rate of 4 °C / min, hold for 10 hours, and then cool to room temperature at a rate of 7 °C / min.

[0180] S3.3 Second aging treatment stage:

[0181] Heat the ingot to 725 °C at a rate of 4 °C / min, hold for 8 hours, and then cool to room temperature at a rate of 7 °C / min.

[0182] Example 4

[0183] Example 4 discloses a preparation method of a nickel-based corrosion-resistant alloy, and the raw materials are configured as follows by weight percentage:

[0184] Chromium (Cr): 23.5 wt%;

[0185] Molybdenum (Mo): 9.5 wt%;

[0186] Iron (Fe): 2.5 wt%;

[0187] Copper (Cu): 3.0 wt%;

[0188] Aluminum (Al): 0.8 wt%;

[0189] Titanium (Ti): 0.5 wt%;

[0190] Tungsten (W): 3.5 wt%;

[0191] Boron (B): 0.005 wt%;

[0192] Yttrium (Y): 0.1 wt%;

[0193] Cerium (Ce): 0.06 wt%;

[0194] Nickel (Ni): the balance.

[0195] The preparation steps are as follows:

[0196] S1: Precision melting step

[0197] S1.1 Vacuum induction melting of raw materials:

[0198] ① Pre-melt the Ni matrix in a low-pressure argon environment of 1400 °C and 10 -2 Pa;

[0199] ② After the Ni matrix is completely melted, raise the melting temperature to 1550 °C, and sequentially add chromium, molybdenum, and tungsten elements, and stir until fully dissolved;

[0200] ③ Add iron and copper at 1550 °C, and continue to stir until fully dissolved;

[0201] ④ Lower the melting temperature to 1520 °C, add aluminum and titanium elements, and stir evenly;

[0202] ⑤ Lower to 1450 °C, and add yttrium, cerium, and boron elements;

[0203] ⑥ Control the melting temperature to 1550 °C, keep it warm for 10 minutes, then cool it to 1400 °C at a rate of 3 °C / min, and then quickly cool it to 600 °C at a rate of 30 °C / min.

[0204] S1.2 Vacuum arc remelting:

[0205] Place the ingot obtained by vacuum induction melting in a vacuum arc furnace with the following conditions: melting current is 7 kA, melting speed is 12 mm / min, and vacuum degree is 0.8 Pa. The remelted ingot is directly transferred to furnace cooling at a temperature higher than 1000 °C.

[0206] S1.3 Furnace cooling control:

[0207] The remelted ingot is slowly cooled to 1000 °C at 2 °C / min, and then quickly cooled to 500 °C at 30 °C / min.

[0208] S2: Directional solidification control steps

[0209] S2.1 Heating stage:

[0210] Heat the ingot from 500 °C to 1520 °C at 3 °C / min.

[0211] S2.2 First cooling and solidification stage:

[0212] Cool the ingot to 1200 °C at 2 °C / min and draw the ingot at 0.5 mm / min to control the uniformity of cooling and crystallization.

[0213] S2.3 Second cooling and solidification stage:

[0214] Quickly cool the ingot to 800 °C at 25 °C / min.

[0215] S3: Variable temperature multi-stage heat treatment steps

[0216] S3.1 Solution treatment:

[0217] Heat the ingot to 1140 °C at 4 °C / min, hold for 3 hours, and then perform oil quenching immediately.

[0218] S3.2 First aging treatment stage:

[0219] Heat the ingot to 875 °C at 4 °C / min, hold for 10 hours, and then cool to room temperature at 7 °C / min.

[0220] S3.3 Second aging treatment stage:

[0221] Heat the ingot to 725 °C at 4 °C / min, hold for 8 hours, and then cool to room temperature at 7 °C / min.

[0222] Example 5

[0223] Example 5 discloses a preparation method of a nickel-based corrosion-resistant alloy, and the raw materials are configured as follows by weight percentage:

[0224] Chromium (Cr): 23.5 wt%;

[0225] Molybdenum (Mo): 9.5 wt%;

[0226] Iron (Fe): 2.5 wt%;

[0227] Copper (Cu): 3.0 wt%;

[0228] Aluminum (Al): 0.8 wt%;

[0229] Titanium (Ti): 0.5 wt%;

[0230] Tungsten (W): 3.5 wt%;

[0231] Boron (B): 0.005 wt%;

[0232] Yttrium (Y): 0.1 wt%;

[0233] Cerium (Ce): 0.06 wt%;

[0234] Niobium (Nb): 0.9 wt%;

[0235] Nickel (Ni): the balance.

[0236] The preparation steps are as follows:

[0237] S1: Precision melting step

[0238] S1.1 Vacuum induction melting of raw materials:

[0239] ① Pre-melt the Ni matrix in a low-pressure argon environment of 10 -2 Pa at 1400 °C;

[0240] ② After the Ni matrix is completely melted, raise the melting temperature to 1550 °C, and sequentially add chromium, molybdenum, tungsten, and niobium elements, and stir until fully dissolved;

[0241] ③ Add iron and copper at 1550 °C, and continue to stir until fully dissolved;

[0242] ④ Lower the melting temperature to 1520 °C, add aluminum and titanium elements, and stir evenly;

[0243] ⑤ Lower the temperature to 1450 °C, and add yttrium, cerium, and boron elements;

[0244] ⑥ Control the melting temperature to 1550 °C, keep it warm for 10 minutes, then cool it to 1400 °C at a rate of 5 °C / min, and then quickly cool it to 600 °C at a rate of 30 °C / min.

[0245] S1.2 Vacuum arc remelting:

[0246] The ingot obtained by vacuum induction melting is placed in a vacuum arc furnace under the following conditions: the melting current is 7 kA, the melting speed is 12 mm / min, and the vacuum degree is 0.8 Pa. The remelted ingot is directly transferred to furnace cooling at a temperature higher than 1000 °C.

[0247] S1.3 Furnace cooling control:

[0248] The remelted ingot is slowly cooled to 1000 °C at 2 °C / min, and then rapidly cooled to 500 °C at 30 °C / min.

[0249] S2: Directional solidification control steps

[0250] S2.1 Heating stage:

[0251] The ingot is heated from 500 °C to 1520 °C at 3 °C / min.

[0252] S2.2 First cooling and solidification stage:

[0253] The ingot is cooled to 1200 °C at 2 °C / min, and the ingot is drawn at 0.5 mm / min to control the cooling and crystallization evenly.

[0254] S2.3 Second cooling and solidification stage:

[0255] The ingot is rapidly cooled to 800 °C at 25 °C / min.

[0256] S3: Variable temperature multi-stage heat treatment steps

[0257] S3.1 Solution treatment:

[0258] The ingot is heated to 1140 °C at 4 °C / min, held for 3 hours, and then quenched in oil immediately.

[0259] S3.2 First aging treatment stage:

[0260] The ingot is heated to 875 °C at 4 °C / min, held for 10 hours, and then cooled to room temperature at 7 °C / min.

[0261] S3.3 Second aging treatment stage:

[0262] The ingot is heated to 725 °C at 4 °C / min, held for 8 hours, and then cooled to room temperature at 7 °C / min.

[0263] Example 6

[0264] Example 6 discloses a preparation method of a nickel-based corrosion-resistant alloy, and the raw materials are configured as follows by weight percentage:

[0265] Chromium (Cr): 23.5 wt%;

[0266] Molybdenum (Mo): 9.5 wt%;

[0267] Iron (Fe): 2.5 wt%;

[0268] Copper (Cu): 3.0 wt%;

[0269] Aluminum (Al): 0.8 wt%;

[0270] Titanium (Ti): 0.5 wt%;

[0271] Tungsten (W): 3.5 wt%;

[0272] Boron (B): 0.005 wt%;

[0273] Yttrium (Y): 0.1 wt%;

[0274] Cerium (Ce): 0.06 wt%;

[0275] Niobium (Nb): 0.9 wt%;

[0276] Zirconium (Zr): 0.05 wt%;

[0277] Nickel (Ni): the balance.

[0278] The preparation steps are as follows:

[0279] S1: Precision melting step

[0280] S1.1 Vacuum induction melting of raw materials:

[0281] ① Pre-melt the Ni matrix in a low-pressure argon environment of 10 -2 Pa at 1400 °C;

[0282] ② After the Ni matrix is completely melted, raise the melting temperature to 1550 °C, and successively add chromium, molybdenum, tungsten, and niobium elements, and stir until fully dissolved;

[0283] ③ Add iron and copper at 1550 °C and continue to stir until fully dissolved;

[0284] ④ Lower the melting temperature to 1520 °C, add aluminum and titanium elements, and stir evenly;

[0285] ⑤ Lower the temperature to 1450 °C, and add yttrium, cerium, zirconium, and boron elements;

[0286] ⑥ Control the melting temperature to 1550 °C, keep it warm for 10 minutes, then cool it to 1400 °C at a rate of 5 °C / min, and then quickly cool it to 600 °C at a rate of 30 °C / min.

[0287] S1.2 Vacuum arc remelting:

[0288] The ingot obtained by vacuum induction melting is placed in a vacuum arc furnace under the following conditions: the melting current is 7 kA, the melting speed is 12 mm / min, and the vacuum degree is 0.8 Pa. The remelted ingot is directly transferred to furnace cooling at a temperature higher than 1000 °C.

[0289] S1.3 Furnace cooling control:

[0290] The remelted ingot is slowly cooled to 1000 °C at 2 °C / min and then rapidly cooled to 500 °C at 30 °C / min.

[0291] S2: Directional solidification control steps

[0292] S2.1 Heating stage:

[0293] The ingot is heated from 500 °C to 1520 °C at 3 °C / min.

[0294] S2.2 First cooling and solidification stage:

[0295] The ingot is cooled to 1200 °C at 2 °C / min and the ingot is drawn at 0.5 mm / min to control uniform cooling and crystallization.

[0296] S2.3 Second cooling and solidification stage:

[0297] The ingot is rapidly cooled to 800 °C at 25 °C / min.

[0298] S3: Variable temperature multi-stage heat treatment steps

[0299] S3.1 Solution treatment:

[0300] The ingot is heated to 1140 °C at 4 °C / min, held for 3 hours, and then immediately oil quenched.

[0301] S3.2 First aging treatment stage:

[0302] The ingot is heated to 875 °C at 4 °C / min, held for 10 hours, and then cooled to room temperature at 7 °C / min.

[0303] S3.3 Second aging treatment stage:

[0304] The ingot is heated to 725 °C at 4 °C / min, held for 8 hours, and then cooled to room temperature at 7 °C / min.

[0305] The difference between Example 7 and Example 6 lies in the setting of some process parameters in the preparation steps. The specific preparation steps are as follows:

[0306] S1: Precision melting steps

[0307] S1.1 Vacuum induction melting of raw materials:

[0308] ① At 1450 °C, keep for 10 -2 Pa in a low-pressure argon environment, pre-melt the Ni matrix;

[0309] ② After the Ni matrix is completely melted, raise the smelting temperature to 1550 °C, and add chromium, molybdenum, tungsten, and niobium elements in sequence, and stir until fully dissolved;

[0310] ③ Add iron and copper at 1525 °C, and continue to stir until fully dissolved;

[0311] ④ Lower the smelting temperature to 1500 °C, add aluminum and titanium elements, and stir evenly;

[0312] ⑤ Lower to 1400 °C, and add yttrium, cerium, zirconium, and boron elements;

[0313] ⑥ Control the smelting temperature to 1550 °C, keep warm for 10 minutes, then cool to 1400 °C at 4 °C / min, and then quickly cool to 500 °C at 20 °C / min.

[0314] S1.2 Vacuum arc remelting:

[0315] Place the ingot obtained by vacuum induction melting in a vacuum arc furnace, with the following conditions: the melting current is 6 kA, the melting speed is 15 mm / min, and the vacuum degree is 0.5 Pa. The remelted ingot is directly transferred to furnace cooling under the condition of higher than 1000 °C.

[0316] S1.3 Furnace cooling control:

[0317] The remelted ingot is slowly cooled to 1000 °C at 3 °C / min, and then quickly cooled to 500 °C at 20 °C / min.

[0318] S2: Directional solidification control steps

[0319] S2.1 Heating stage:

[0320] Heat the ingot from 500 °C to 1500 °C at 5 °C / min.

[0321] S2.2 First cooling and solidification stage:

[0322] Cool the ingot to 1200 °C at 2 °C / min, and draw the ingot at 0.5 mm / min to control the cooling and crystallization evenly.

[0323] S2.3 Second cooling and solidification stage:

[0324] Cool the ingot to 800 °C at 30 °C / min quickly.

[0325] S3: Variable-temperature multi-stage heat treatment steps

[0326] S3.1 Solution treatment:

[0327] The ingot was heated to 1120 °C at 5 °C / min, held for 3 hours, and then oil quenched.

[0328] S3.2 First aging treatment stage:

[0329] The ingot was heated to 850 °C at 3 °C / min, held for 10 hours, and then cooled to room temperature at 7 °C / min.

[0330] S3.3 Second aging treatment stage:

[0331] The ingot was heated to 750 °C at 4 °C / min, held for 8 hours, and then cooled to room temperature at 7 °C / min.

[0332] Example 8

[0333] Example 8 discloses a preparation method of a nickel-based corrosion-resistant alloy, and the raw materials are configured as follows by weight percentage:

[0334] Chromium (Cr): 22 wt%;

[0335] Molybdenum (Mo): 8 wt%;

[0336] Iron (Fe): 1 wt%;

[0337] Copper (Cu): 1.8 wt%;

[0338] Aluminum (Al): 0.5 wt%;

[0339] Titanium (Ti): 0.3 wt%;

[0340] Tungsten (W): 1.5 wt%;

[0341] Boron (B): 0.002 wt%;

[0342] Yttrium (Y): 0.02 wt%;

[0343] Cerium (Ce): 0.02 wt%;

[0344] Niobium (Nb): 0.8 wt%;

[0345] Zirconium (Zr): 0.01 wt%;

[0346] Nickel (Ni): the balance.

[0347] The preparation steps are as follows:

[0348] S1: Precision melting step

[0349] S1.1 Vacuum induction melting of raw materials:

[0350] ① At 1430 °C, hold for 10-2 In an argon environment with a low pressure of Pa, pre-melt the Ni matrix;

[0351] ② After the Ni matrix is completely melted, raise the melting temperature to 1520 °C, and successively add chromium, molybdenum, tungsten, and niobium elements, and stir until fully dissolved;

[0352] ③ Raise the temperature to 1550 °C, add iron and copper at 1550 °C, and continue to stir until fully dissolved;

[0353] ④ Lower the melting temperature to 1510 °C, add aluminum and titanium elements, and stir evenly;

[0354] ⑤ Lower the temperature to 1420 °C, and add yttrium, cerium, zirconium, and boron elements;

[0355] ⑥ Control the melting temperature to 1530 °C, keep it warm for 10 minutes, then cool it to 1400 °C at a rate of 5 °C / min, and then quickly cool it to 550 °C at a rate of 25 °C / min.

[0356] S1.2 Vacuum arc remelting:

[0357] Place the ingot obtained by vacuum induction melting in a vacuum arc furnace, with the following conditions: the melting current is 7 kA, the melting speed is 12 mm / min, and the vacuum degree is 0.8 Pa. The remelted ingot is directly transferred to furnace cooling under the condition of higher than 1000 °C.

[0358] S1.3 Furnace cooling control:

[0359] The remelted ingot is slowly cooled to 1000 °C at a rate of 2 °C / min, and then quickly cooled to 500 °C at a rate of 25 °C / min.

[0360] S2: Directional solidification control steps

[0361] S2.1 Heating stage:

[0362] Heat the ingot from 500 °C to 1500 °C at a rate of 3 °C / min.

[0363] S2.2 First cooling and solidification stage:

[0364] Cool the ingot to 1200 °C at a rate of 4 °C / min, and draw the ingot at a rate of 0.6 mm / min to control the cooling and crystallization evenly.

[0365] S2.3 Second cooling and solidification stage:

[0366] Cool the ingot to 800 °C at a rate of 25 °C / min.

[0367] S3: Variable temperature multi-stage heat treatment steps

[0368] S3.1 Solution treatment:

[0369] The ingot was heated to 1140 °C at 4 °C / min, held for 3 hours, and then oil quenched.

[0370] S3.2 First aging treatment stage:

[0371] The ingot was heated to 870 °C at 3 °C / min, held for 10 hours, and then cooled to room temperature at 5 °C / min.

[0372] S3.3 Second aging treatment stage:

[0373] The ingot was heated to 730 °C at 3 °C / min, held for 8 hours, and then cooled to room temperature at 5 °C / min.

[0374] Example 9

[0375] Example 9 discloses a preparation method of a nickel-based corrosion-resistant alloy, and the raw materials are configured with the following raw materials by weight percentage:

[0376] Chromium (Cr): 25 wt%

[0377] Molybdenum (Mo): 10 wt%

[0378] Iron (Fe): 3 wt%

[0379] Copper (Cu): 3.5 wt%

[0380] Aluminum (Al): 1.2 wt%

[0381] Titanium (Ti): 0.8 wt%

[0382] Tungsten (W): 3.5 wt%

[0383] Boron (B): 0.01 wt%

[0384] Yttrium (Y): 0.12 wt%

[0385] Cerium (Ce): 0.07 wt%

[0386] Niobium (Nb): 1.8 wt%

[0387] Zirconium (Zr): 0.1 wt%

[0388] Nickel (Ni): the balance.

[0389] The preparation steps are as follows:

[0390] S1: Precision melting step

[0391] S1.1 Vacuum induction melting of raw materials:

[0392] ① At 1450 °C, hold for 10 -2In a low-pressure argon environment of Pa, pre-melt the Ni matrix;

[0393] ② After the Ni matrix is completely melted, raise the melting temperature to 1550 °C, and sequentially add chromium, molybdenum, tungsten, and niobium elements, and stir until fully dissolved;

[0394] ③ At 1550 °C, add iron and copper, and continue to stir until fully dissolved;

[0395] ④ Lower the melting temperature to 1520 °C, add aluminum and titanium elements, and stir evenly;

[0396] ⑤ Lower the temperature to 1450 °C, and add yttrium, cerium, zirconium, and boron elements;

[0397] ⑥ Control the melting temperature to 1500 °C, hold for 10 minutes, then cool to 1400 °C at a rate of 3 °C / min, and then quickly cool to 600 °C at a rate of 30 °C / min.

[0398] S1.2 Vacuum arc remelting:

[0399] Place the ingot obtained by vacuum induction melting in a vacuum arc furnace, with the following conditions: melting current is 8 kA, melting speed is 15 mm / min, and vacuum degree is 1 Pa. The remelted ingot is directly transferred to furnace cooling under the condition of higher than 1000 °C.

[0400] S1.3 Furnace cooling control:

[0401] The remelted ingot is slowly cooled to 1000 °C at a rate of 5 °C / min, and then quickly cooled to 500 °C at a rate of 30 °C / min.

[0402] S2: Directional solidification control steps

[0403] S2.1 Heating stage:

[0404] Heat the ingot from 500 °C to 1550 °C at a rate of 4 °C / min.

[0405] S2.2 First cooling and solidification stage:

[0406] Cool the ingot to 1200 °C at a rate of 5 °C / min, and draw the ingot at a rate of 1 mm / min to control the cooling and crystallization evenly.

[0407] S2.3 Second cooling and solidification stage:

[0408] Quickly cool the ingot to 800 °C at a rate of 30 °C / min.

[0409] S3: Variable-temperature multi-stage heat treatment steps

[0410] S3.1 Solution treatment:

[0411] The ingot was heated to 1160 °C at 5 °C / min, held for 2 hours, and then oil quenched.

[0412] S3.2 First aging treatment stage:

[0413] The ingot was heated to 900 °C at 5 °C / min, held for 8 hours, and then cooled to room temperature at 10 °C / min.

[0414] S3.3 Second aging treatment stage:

[0415] The ingot was heated to 750 °C at 5 °C / min, held for 6 hours, and then cooled to room temperature at 10 °C / min.

[0416] Comparative example 1

[0417] Comparative example 1 discloses a preparation method of a nickel-based corrosion-resistant alloy. The raw materials are configured as follows by weight percentage:

[0418] Chromium (Cr): 23.5 wt%;

[0419] Iron (Fe): 2.5 wt%;

[0420] Copper (Cu): 3.0 wt%;

[0421] Aluminum (Al): 0.8 wt%;

[0422] Titanium (Ti): 0.5 wt%;

[0423] Boron (B): 0.005 wt%;

[0424] Nickel (Ni): the balance.

[0425] The preparation steps are as follows:

[0426] S1: Precision melting step

[0427] S1.1 Vacuum induction melting of raw materials:

[0428] ① In a low-pressure argon environment of 1400 °C and 10 -2 Pa, pre-melt the Ni matrix;

[0429] ② After the Ni matrix is completely melted, raise the melting temperature to 1550 °C, add chromium, and stir until fully dissolved;

[0430] ③ At 1550 °C, add iron and copper, and continue to stir until fully dissolved;

[0431] ④ Lower the melting temperature to 1520 °C, add aluminum and titanium elements, and stir evenly;

[0432] ⑤ Lower to 1450 °C and add boron element;

[0433] ⑥ Control the melting temperature to 1550 °C. After holding for 10 minutes, cool it to 1400 °C at a rate of 5 °C / min, and then quickly cool it to 600 °C at a rate of 30 °C / min.

[0434] S1.2 Vacuum arc remelting:

[0435] Place the ingot obtained by vacuum induction melting in a vacuum arc furnace with the following conditions: melting current is 7 kA, melting speed is 12 mm / min, and vacuum degree is 0.8 Pa. The remelted ingot is directly transferred to furnace cooling under the condition of higher than 1000 °C.

[0436] S1.3 Furnace cooling control:

[0437] The remelted ingot is slowly cooled to 1000 °C at a rate of 2 °C / min, and then quickly cooled to 500 °C at a rate of 30 °C / min.

[0438] S2: Directional solidification control steps

[0439] S2.1 Heating stage:

[0440] Heat the ingot from 500 °C to 1520 °C at a rate of 3 °C / min.

[0441] S2.2 First cooling and solidification stage:

[0442] Cool the ingot to 1200 °C at a rate of 2 °C / min, and draw the ingot at a rate of 0.5 mm / min to control the uniformity of cooling and crystallization.

[0443] S2.3 Second cooling and solidification stage:

[0444] Quickly cool the ingot to 800 °C at a rate of 25 °C / min.

[0445] S3: Variable temperature multi-stage heat treatment steps

[0446] S3.1 Solution treatment:

[0447] Heat the ingot to 1140 °C at a rate of 4 °C / min, hold for 3 hours, and then perform oil quenching immediately.

[0448] S3.2 First aging treatment stage:

[0449] Heat the ingot to 875 °C at a rate of 4 °C / min, hold for 10 hours, and then cool it to room temperature at a rate of 7 °C / min.

[0450] S3.3 Second aging treatment stage:

[0451] Heat the ingot to 725 °C at a rate of 4 °C / min, hold for 8 hours, and then cool it to room temperature at a rate of 7 °C / min.

[0452] Comparative Example 2

[0453] Comparative Example 2 discloses a preparation method of a nickel-based corrosion-resistant alloy, and the raw materials are configured according to the following weight percentages:

[0454] Chromium (Cr): 23.5 wt%;

[0455] Molybdenum (Mo): 8.5 wt%;

[0456] Iron (Fe): 2.5 wt%;

[0457] Copper (Cu): 3.0 wt%;

[0458] Aluminum (Al): 0.8 wt%;

[0459] Titanium (Ti): 0.5 wt%;

[0460] Tungsten (W): 2.5 wt%;

[0461] Boron (B): 0.005 wt%;

[0462] Yttrium (Y): 0.05 wt%;

[0463] Cerium (Ce): 0.04 wt%;

[0464] Nickel (Ni): the balance.

[0465] The preparation steps are as follows:

[0466] S1: Melting step

[0467] S1.1 Vacuum induction melting of raw materials: At 1550 °C, in a low-pressure argon environment of 10 -2 Pa, nickel, chromium, molybdenum, tungsten, iron, copper, aluminum, titanium, yttrium, cerium, and boron are heated and melted and mixed evenly. After holding for 10 minutes, it is cooled to room temperature at 30 °C;

[0468] S1.2 Vacuum arc remelting:

[0469] The ingot obtained by vacuum induction melting is placed in a vacuum arc furnace, and the conditions are as follows: the melting current is 7 kA, the melting speed is 12 mm / min, and the vacuum degree is 0.8 Pa. The remelted ingot is directly transferred to furnace cooling under the condition of higher than 1000 °C.

[0470] S1.3 Furnace cooling control:

[0471] The remelted ingot is slowly cooled to 1000 °C at 2 °C / min, and then quickly cooled to 500 °C at 30 °C / min.

[0472] S2: Directional solidification control step

[0473] S2.1 Heating stage:

[0474] The ingot was heated from 500 °C to 1520 °C at a rate of 3 °C / min.

[0475] S2.2 First cooling and solidification stage:

[0476] The ingot was cooled to 1200 °C at a rate of 2 °C / min, and the ingot was drawn at a rate of 0.5 mm / min to control uniform cooling and crystallization.

[0477] S2.3 Second cooling and solidification stage:

[0478] The ingot was rapidly cooled to 800 °C at a rate of 25 °C / min.

[0479] S3: Variable-temperature multi-stage heat treatment step

[0480] S3.1 Solution treatment:

[0481] The ingot was heated to 1140 °C at a rate of 4 °C / min, held for 3 hours, and then oil quenched.

[0482] S3.2 First aging treatment stage:

[0483] The ingot was heated to 875 °C at a rate of 4 °C / min, held for 10 hours, and then cooled to room temperature at a rate of 7 °C / min.

[0484] S3.3 Second aging treatment stage:

[0485] The ingot was heated to 725 °C at a rate of 4 °C / min, held for 8 hours, and then cooled to room temperature at a rate of 7 °C / min.

[0486] Testing method

[0487] The following tests were carried out on Examples 1-9 and Comparative Examples 1-2:

[0488] 1. Tensile strength and elongation were tested according to GB / T228.1-2021 "Metallic materials - Tensile testing - Part 1: Method of test at room temperature".

[0489] 2. Hardness was tested according to GB / T230.1-2018 "Metallic materials - Rockwell hardness test - Part 1: Test method".

[0490] 3. Corrosion resistance was tested according to ASTM G28-2002.

[0491] 4. Pitting corrosion rate was tested according to ASTM G48-2011 "Standard test method for pitting and crevice corrosion resistance of stainless steels and related alloys by use of ferric chloride solution".

[0492]

[0493] According to the above test results, it can be seen that the element ratio design of the nickel-based alloy of the present invention is combined with the fine preparation process, achieving a better corrosion resistance effect.

[0494] The above are only the preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the idea of the present invention belong to the protection scope of the present invention. It should be pointed out that for those of ordinary skill in the art, several improvements and refinements made without departing from the principle of the present invention should also be regarded as within the protection scope of the present invention.

Claims

1. A nickel-based corrosion-resistant alloy, characterized in that: The following elements are included in weight percentage: Chromium: 22-25wt%; Molybdenum: 8-10wt%; Iron: 1-3wt%; Copper: 1.8-3.5wt%; Aluminum: 0.5-1.2wt%; Titanium: 0.3-0.8wt%; Tungsten: 1.5-3.5wt%; Boron: 0.002-0.01wt%; Yttrium: 0.02-0.12wt%; Cerium: 0.02-0.07wt%; Nickel: balance; The preparation method of the nickel-based corrosion-resistant alloy is as follows: S1: precision melting step; The precise melting step includes three steps: vacuum induction melting of raw materials, vacuum arc remelting and precise furnace cooling control; The specific operation of the S1 precision smelting step is as follows: S1.1 Vacuum induction melting of raw materials: ① at 1400-1450℃, keep for 10 -2 ② After the Ni matrix is ​​completely melted, the melting temperature is increased to 1500-1550°C, and chromium, molybdenum, and tungsten elements are added in order from high melting point to low melting point; ③After the elements are fully melted, add iron and copper elements at a temperature of 1550℃; ④ After the elements are fully melted, the melting temperature is lowered to 1500-1520℃, and aluminum and titanium elements are added; ⑤ After they are completely melted, the melting temperature is controlled to 1400-1450℃, and yttrium, cerium and boron elements are added; ⑥ After they are completely melted, the melting temperature is controlled to 1500-1550℃, kept warm for 10 minutes, cooled to 1400℃ at a low speed of 3-5℃ / min, and then quickly cooled to 500-600℃ at 20-30℃ / min; S1.2 Vacuum arc remelting: vacuum induction melted ingots are subjected to vacuum arc remelting under the conditions of controlling the melting current to 6-8kA, melting speed to 10-15mm / min, and vacuum degree to 0.5-1Pa to obtain remelted ingots, which are directly transferred to furnace cooling at a temperature higher than 1000°C; S1.3 Furnace cooling control: first slowly cool the remelted ingot to 1000°C at 2-5°C / min; then quickly cool it to 500°C at 20-30°C / min; S2: directional solidification control step; The directional solidification control step includes a heating stage, a first cooling and solidification stage, and a second cooling and solidification stage, wherein the cooling rate of the first cooling and solidification stage is lower than the cooling rate of the second cooling and solidification stage; The specific operation of the S2 directional solidification control step is as follows: S2.1 Heating stage: heat the ingot from 500°C to 1500-1550°C at 3-5°C / min; S2.2 The first cooling and solidification stage: the ingot is cooled to 1200°C at a low speed of 2-5°C / min, and the ingot is pulled at a speed of 0.1-1mm / min; S2.3 Second cooling and solidification stage: the ingot is rapidly cooled to 800°C at 20-30°C / min; S3: variable temperature multi-stage heat treatment step; The variable temperature multi-stage heat treatment step includes a solution treatment, a first aging treatment stage, a second aging treatment stage The specific operation of the S3 variable temperature multi-stage heat treatment step is as follows: S3.1 Solution treatment: heat the ingot to 1120-1160℃ at a rate of 3-5℃ / min, keep it at this temperature for 2-4 hours, and immediately perform oil quenching and rapid cooling; S3.2 First aging treatment stage: heat the ingot to 850-900°C at a rate of 3-5°C / min, keep it at that temperature for 8-12 hours, and then cool it to room temperature at a rate of 5-10°C / min; S3.3 Second aging treatment stage: heat the ingot to 700-750°C at a rate of 3-5°C / min, keep it at that temperature for 6-10 hours, and then cool it to room temperature at a rate of 5-10°C / min.

2. A nickel-based corrosion-resistant alloy according to claim 1, characterized in that: It also includes niobium element, and the weight percentage of the niobium element is 0.8-1.8wt%.

3. A nickel-based corrosion-resistant alloy according to claim 1, characterized in that: The weight percentage of the molybdenum element is 9-10wt%; the weight percentage of the tungsten element is 3-3.5wt%.

4. The nickel-based corrosion-resistant alloy according to claim 1, characterized in that: The weight percentage of the yttrium element is 0.08-0.12wt%; the weight percentage of the cerium element is 0.05-0.07wt%.

5. The nickel-based corrosion-resistant alloy according to claim 1, characterized in that: It also includes zirconium element, and the weight percentage of the zirconium element is 0.01-0.1wt%.

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