N08120 nickel-based high-temperature alloy steel ingot and preparation method thereof

Abstract

The invention provides an N08120 nickel-based high-temperature alloy steel ingot and a preparation method thereof, and belongs to the technical field of metallurgy. By adding Zr and limiting the content of Zr and B, the mechanical property of the nickel-based alloy can be improved on the basis of reducing the content of N and the content of Nb and Ta; by adding Hf and limiting the content of Hf and Cr, the mechanical property of the nickel-based alloy can be further improved; the mechanical property of the nickel-based alloy can be further improved by limiting the total content of Al and Mo; and by designing the alloy components, the mechanical property of the nickel-based alloy can be further improved.

Description

Technical Field

[0001] This invention belongs to the field of metallurgical technology, specifically relating to an N08120 nickel-based high-temperature alloy steel ingot and its preparation method. Background Technology

[0002] N08120 nickel-based alloy is a widely used high-temperature alloy, mainly used in the manufacture of high-temperature alloy steel forgings for polycrystalline silicon reactors for solar photovoltaic power generation, impellers and blades for new energy cycle energy storage systems of steam heat pump compressors, valve stems of medium-pressure regulating valves for double reheat ultra-supercritical steam turbines, condensate pipes for high-temperature gas-cooled reactors in nuclear power, sealing rings of various specifications, and components for new energy hydrogen atmosphere / hydrocarbon reforming processes and high-temperature resistant components for solar nuclear fusion, as well as other key parts in the aerospace and aircraft engine fields.

[0003] Currently, the chemical composition of N08120 nickel-based alloy, by mass percentage, includes Ni 35-39%, Cr 23-27%, C 0.02-0.10%, Si≤1.00%, Mn≤1.5%, P≤0.040%, S≤0.030%, Cu≤0.50%, Al≤0.40%, Ti≤0.20%, Nb+Ta 0.40-0.90%, Mo≤2.5%, W≤2.5%, Co≤3.0%, N 0.15-0.30%, B≤0.010%, and the balance iron (ASTM B366 standard). However, this nickel-based alloy has poor mechanical properties. Therefore, how to improve nickel-based alloys to enhance their mechanical properties has become an urgent technical problem to be solved in this field. Summary of the Invention

[0004] The purpose of this invention is to provide an N08120 nickel-based superalloy steel ingot and its preparation method. Forgings prepared from the nickel-based superalloy steel ingot provided by this invention possess excellent mechanical properties.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides an N08120 nickel-based high-temperature alloy steel ingot, the chemical composition of which, by mass percentage, includes: Ni 36.5~38%, Cr 25.0~25.4%, C 0.02~0.05%, Si 0.40~0.48%, Mn 0.60~0.70%, P≤0.020%, S≤0.005%, Cu 0.10~0.20%, Al 0.02~0.08%, Ti 0.02~0.05%, Nb+Ta 0.10~0.30%, Mo 0.50~0.75%, W 0.01~0.08%, Co 0.85~1.0%, N 0.15~0.30%, B 0.002~0.005%, O≤10ppm, H≤1.2ppm, Nb 0.60~0.90%, Zr 0.001~0.005%, Hf 0.01~0.05%, and the balance Fe; The total mass percentage of B and Zr is 0.004% to 0.006%; The total mass percentage of Al and Mo is 0.55~0.70%; The total mass percentage of Hf and Cr is 25.2% to 25.4%.

[0006] Preferably, the chemical composition, by mass percentage, includes: Ni 36.8~37.5%, Cr 25.1~25.3%, C 0.03~0.04%, Si 0.42~0.46%, Mn 0.62~0.68%, P≤0.020%, S≤0.005%, Cu 0.12~0.18%, Al 0.03~0.07%, Ti 0.03~0.04%, Nb+Ta 0.15~0.25%, Mo 0.55~0.70%, W 0.02~0.07%, Co 0.88~0.95%, N 0.20~0.25%, B 0.003~0.004%, O≤10ppm, H≤1.2ppm, Nb 0.65~0.85%, Zr 0.002~0.004%, Hf 0.02~0.04% and balance Fe.

[0007] Preferably, the chemical composition, by mass percentage, includes: Ni 37.0~37.3%, Cr 25.2~25.3%, C 0.03~0.04%, Si 0.43~0.45%, Mn 0.64~0.66%, P≤0.020%, S≤0.005%, Cu 0.14~0.16%, Al 0.04~0.06%, Ti 0.03~0.04%, Nb+Ta 0.18~0.22%, Mo 0.60~0.65%, W 0.03~0.06%, Co 0.90~0.93%, N 0.21~0.24%, B 0.003~0.004%, O≤10ppm, H≤1.2ppm, Nb 0.70~0.80%, Zr 0.003~0.004%, Hf 0.03~0.04% and balance Fe.

[0008] Preferably, the total mass percentage of B and Zr is 0.005~0.0055%.

[0009] Preferably, the total mass percentage of B and Zr is 0.0052~0.0054%.

[0010] Preferably, the total mass percentage of Al and Mo is 0.60~0.65%.

[0011] Preferably, the total mass percentage of Al and Mo is 0.62~0.64%.

[0012] Preferably, the total mass percentage of Hf and Cr is 25.25~25.35%.

[0013] Preferably, the total mass percentage of Hf and Cr is 25.3%.

[0014] The present invention also provides a method for preparing the N08120 nickel-based high-temperature alloy steel ingot described in the above technical solution, comprising: The raw materials are smelted and cast sequentially to obtain N08120 nickel-based high-temperature alloy steel ingots.

[0015] This invention provides an N08120 nickel-based high-temperature alloy steel ingot, the chemical composition of which, by mass percentage, includes: Ni 36.5~38%, Cr 25.0~25.4%, C 0.02~0.05%, Si 0.40~0.48%, Mn 0.60~0.70%, P≤0.020%, S≤0.005%, Cu 0.10~0.20%, Al 0.02~0.08%, Ti 0.02~0.05%, Nb+Ta 0.10~0.30%, Mo 0.50~0.75%, W 0.01~0.08%, Co 0.85~1.0%, N 0.15~0.30%, B 0.002~0.005%, O≤10ppm, H≤1.2ppm, Nb 0.60~0.90%, Zr The alloy composition comprises 0.001~0.005% B, 0.01~0.05% Hf, and the balance Fe; the total mass percentage of B and Zr is 0.004~0.006%; the total mass percentage of Al and Mo is 0.55~0.70%; and the total mass percentage of Hf and Cr is 25.2~25.4%. This invention improves the mechanical properties of nickel-based alloys by adding Zr and limiting the contents of Zr and B while reducing the contents of N and Nb+Ta; further improves the mechanical properties of nickel-based alloys by adding Hf and limiting the contents of Hf and Cr; further improves the mechanical properties of nickel-based alloys by limiting the total content of Al and Mo; and further improves the mechanical properties of nickel-based alloys by designing the alloy composition. Detailed Implementation

[0016] This invention provides an N08120 nickel-based high-temperature alloy steel ingot, the chemical composition of which, by mass percentage, includes: Ni 36.5~38%, Cr 25.0~25.4%, C 0.02~0.05%, Si 0.40~0.48%, Mn 0.60~0.70%, P≤0.020%, S≤0.005%, Cu 0.10~0.20%, Al 0.02~0.08%, Ti 0.02~0.05%, Nb+Ta 0.10~0.30%, Mo 0.50~0.75%, W 0.01~0.08%, Co 0.85~1.0%, N 0.15~0.30%, B 0.002~0.005%, O≤10ppm, H≤1.2ppm, Nb 0.60~0.90%, Zr 0.001~0.005%, Hf 0.01~0.05%, and the balance Fe; The total mass percentage of B and Zr is 0.004% to 0.006%; The total mass percentage of Al and Mo is 0.55~0.70%; The total mass percentage of Hf and Cr is 25.2% to 25.4%.

[0017] The N08120 nickel-based high-temperature alloy steel ingot provided by this invention comprises 36.5% to 38% Ni by mass percentage. As one embodiment, the mass percentage of Ni can be 36.6%, 36.7%, 36.8%, 36.9%, 37%, 37.1%, 37.2%, 37.3%, 37.4%, 37.5%, 37.6%, 37.7%, 37.8%, or 37.9%. In this invention, the Ni can improve the alloy's oxidation resistance at high temperatures, thereby improving the alloy's high-temperature mechanical properties; furthermore, a high Ni content can improve the alloy's mechanical properties.

[0018] The chemical composition of the N08120 nickel-based high-temperature alloy steel ingot provided by the present invention includes 25.0-25.4% Cr by mass percentage. As one embodiment, the mass percentage of Cr can be 25.1%, 25.2%, or 25.3%. In the present invention, the Cr can improve the alloy's oxidation resistance at high temperatures, thereby improving the alloy's high-temperature mechanical properties.

[0019] The chemical composition of the N08120 nickel-based high-temperature alloy steel ingot provided by this invention, by mass percentage, includes 0.02-0.05% C. As one embodiment, the mass percentage of C can be 0.03% or 0.04%. In this invention, C is a grain boundary strengthening element. Carbides generally agglomerate at grain boundaries as fine dispersions, which can effectively pin dislocations, increase the resistance to dislocation movement, and improve the overall performance of the alloy. By limiting the mass percentage of C within the above range, the room temperature and high-temperature mechanical properties of the alloy can be further improved.

[0020] The N08120 nickel-based high-temperature alloy steel ingot provided by this invention comprises 0.40-0.48% Si by mass percentage. As one embodiment, the mass percentage of Si can be 0.41%, 0.42%, 0.43%, 0.44%, 0.45%, 0.46%, or 0.47%. In this invention, limiting the mass percentage of Si within the above range further improves the room temperature and high-temperature mechanical properties of the alloy.

[0021] The N08120 nickel-based high-temperature alloy steel ingot provided by this invention comprises 0.60-0.70% Mn by mass percentage. As one embodiment, the mass percentage of Mn can be 0.61%, 0.62%, 0.63%, 0.64%, 0.65%, 0.66%, 0.67%, 0.68%, or 0.69%. In this invention, limiting the mass percentage of Mn within the above range further improves the room temperature and high-temperature mechanical properties of the alloy.

[0022] The chemical composition of the N08120 nickel-based high-temperature alloy steel ingot provided by this invention, by mass percentage, includes P ≤ 0.020%. As one embodiment, the mass percentage of P can be ≤ 0.015%. In this invention, P is a harmful element; by reducing its content, the room temperature and high-temperature mechanical properties of the alloy can be further improved.

[0023] The chemical composition of the N08120 nickel-based high-temperature alloy steel ingot provided by this invention, by mass percentage, includes S ≤ 0.005%. As one embodiment, the mass percentage of S can be ≤ 0.004% or even ≤ 0.003%. In this invention, S is a harmful element; by reducing its content, the room temperature and high-temperature mechanical properties of the alloy can be further improved.

[0024] The chemical composition of the N08120 nickel-based high-temperature alloy steel ingot provided by this invention, by mass percentage, includes 0.10~0.20% Cu. As one embodiment, the mass percentage of Cu can be 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, or 0.19%. In this invention, limiting the mass percentage of Cu within the above range can further improve the room temperature and high-temperature mechanical properties of the alloy.

[0025] The chemical composition of the N08120 nickel-based high-temperature alloy steel ingot provided by this invention, by mass percentage, includes 0.02-0.08% Al. As one embodiment, the mass percentage of Al can be 0.03%, 0.04%, 0.05%, 0.06%, or 0.07%. In this invention, the Al can form sufficient γ′ phase, increasing the solid solution temperature and volume fraction of the γ′ phase, effectively improving the alloy's resistance to high-temperature oxidation, and simultaneously increasing its density, thereby improving the alloy's mechanical properties at both room temperature and high temperature.

[0026] The N08120 nickel-based high-temperature alloy steel ingot provided by this invention comprises 0.02-0.05% Ti by mass percentage. As one embodiment, the mass percentage of Ti can be 0.03% or 0.04%. In this invention, the Ti can form sufficient γ′ phase, increasing the γ′ phase solution temperature and volume fraction, effectively improving the alloy's resistance to high-temperature oxidation, and simultaneously increasing density, thereby improving the alloy's mechanical properties at both room temperature and high temperature.

[0027] The N08120 nickel-based superalloy steel ingot provided by this invention comprises 0.10-0.30% Nb+Ta by mass percentage. As one embodiment, the mass percentage of Nb+Ta can be 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.20%, 0.21%, 0.22%, 0.23%, 0.24%, 0.25%, 0.26%, 0.27%, 0.28%, or 0.29%. In this invention, limiting the Nb+Ta content further improves the mechanical properties of the alloy.

[0028] In this invention, the mass ratio of Nb to Ta is preferably 1:(1~3), more preferably 1:2. Limiting the mass ratio of Nb to Ta within the above range further improves the mechanical properties of the alloy.

[0029] The N08120 nickel-based superalloy steel ingot provided by this invention comprises 0.50-0.75% Mo by mass percentage. As one embodiment, the mass percentage of Mo can be 0.51%, 0.52%, 0.53%, 0.54%, 0.55%, 0.56%, 0.57%, 0.58%, 0.59%, 0.60%, 0.61%, 0.62%, 0.63%, 0.64%, 0.65%, 0.66%, 0.67%, 0.68%, 0.69%, 0.70%, 0.71%, 0.72%, 0.73%, or 0.74%. In this invention, Mo has a strong solid solution effect on the γ-matrix and can simultaneously improve the interatomic bonding force, increase the recrystallization temperature and diffusion activation energy of the alloy, thereby effectively improving the mechanical properties of the alloy.

[0030] The chemical composition of the N08120 nickel-based superalloy steel ingot provided by this invention, by mass percentage, includes 0.01~0.08% W. As one embodiment, the mass percentage of W can be 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, or 0.07%. In this invention, W can provide solid solution strengthening to the matrix. The addition of W causes lattice expansion, restricting dislocation movement and enhancing the alloy's strength, thereby improving its mechanical properties.

[0031] The N08120 nickel-based superalloy steel ingot provided by this invention comprises 0.85-1.0% Co by mass percentage. As one embodiment, the mass percentage of Co can be 0.86%, 0.87%, 0.88%, 0.89%, 0.90%, 0.91%, 0.92%, 0.93%, 0.94%, 0.95%, 0.96%, 0.97%, 0.98%, or 0.99%. In this invention, the addition of Co can reduce the stacking fault energy of the γ matrix, playing a role in solid solution strengthening, thereby improving the alloy's creep strength and creep resistance.

[0032] The chemical composition of the N08120 nickel-based superalloy steel ingot provided by this invention, by mass percentage, includes 0.15-0.30% N. As one embodiment, the mass percentage of N can be 0.16%, 0.17%, 0.18%, 0.19%, 0.20%, 0.21%, 0.22%, 0.23%, 0.24%, 0.25%, 0.26%, 0.27%, 0.28%, or 0.29%. In this invention, by limiting the N content, the refinement of the solidification structure of the material is promoted, thereby further improving the mechanical properties of the alloy.

[0033] The chemical composition of the N08120 nickel-based superalloy steel ingot provided by this invention, by mass percentage, includes 0.002% to 0.005% B. As one embodiment, the mass percentage of B can be 0.003% or 0.004%. In this invention, B, as an important grain boundary and interdendritic strengthening element, can be added to the alloy as a microstructure stabilizing element, which is beneficial to improving the microstructure stability of the alloy, refining the grain size of the microstructure, and thus improving the mechanical properties of the alloy.

[0034] The chemical composition of the N08120 nickel-based high-temperature alloy steel ingot provided by this invention, by mass percentage, includes O ≤ 10 ppm. In this invention, O is a harmful element; by reducing its content, the inclusion content of the molten steel is reduced, the purity of the molten steel is improved, and the room temperature and high temperature mechanical properties of the alloy can be further improved.

[0035] The chemical composition of the N08120 nickel-based high-temperature alloy steel ingot provided by this invention, by mass percentage, includes H ≤ 1.2 ppm. In this invention, H is a harmful element; by reducing its content, hydrogen embrittlement and white spot defects in the internal structure of the steel ingot are avoided, thereby further improving the room temperature and high temperature mechanical properties of the alloy.

[0036] The N08120 nickel-based superalloy steel ingot provided by this invention comprises 0.60-0.90% Nb by mass percentage. As one embodiment, the mass percentage of Nb can be 0.61%, 0.62%, 0.63%, 0.64%, 0.65%, 0.66%, 0.67%, 0.68%, 0.69%, 0.70%, 0.71%, 0.72%, 0.73%, 0.74%, 0.75%, 0.76%, 0.77%, 0.78%, 0.79%, 0.80%, 0.81%, 0.82%, 0.83%, 0.84%, 0.85%, 0.86%, 0.87%, 0.88%, or 0.89%. In this invention, controlling the Nb content within the above range can further improve the mechanical properties of the alloy.

[0037] The chemical composition of the N08120 nickel-based superalloy steel ingot provided by this invention, by mass percentage, includes 0.001~0.005% Zr. As one embodiment, the mass percentage of Zr can be 0.002%, 0.003%, or 0.004%. In this invention, the Zr segregation at grain boundaries can improve grain boundary strength, improve carbide morphology and distribution, thereby enhancing the mechanical properties of the alloy.

[0038] The chemical composition of the N08120 nickel-based superalloy steel ingot provided by this invention includes 0.01-0.05% Hf by mass percentage. As one embodiment, the mass percentage of Hf can be 0.02%, 0.03%, or 0.04%. In this invention, the Hf further enhances the high-temperature properties of the alloy, especially its plasticity.

[0039] The chemical composition of the N08120 nickel-based superalloy steel ingot provided by this invention, by weight percentage, includes the balance Fe. In this invention, the Fe is a matrix element.

[0040] In this invention, the total mass percentage of B and Zr is 0.004~0.006%. As one embodiment, the total mass percentage of B and Zr can be 0.005%, 0.0052%, 0.0054%, or 0.0055%. This invention, by limiting the content of Zr and B, can improve the mechanical properties of nickel-based alloys while reducing the N and Nb+Ta content.

[0041] In this invention, the total mass percentage of Al and Mo is 0.55% to 0.70%. As one embodiment, the total mass percentage of Al and Mo can be 0.56%, 0.57%, 0.58%, 0.59%, 0.60%, 0.61%, 0.62%, 0.63%, 0.64%, 0.65%, 0.66%, 0.67%, 0.68%, or 0.69%. This invention, by limiting the total content of Al and Mo, can further improve the mechanical properties of nickel-based alloys.

[0042] In this invention, the total mass percentage of Hf and Cr is 25.2% to 25.4%. As one embodiment, the total mass percentage of Hf and Cr can be 25.24%, 25.25%, 25.30%, 25.31%, 25.32%, 25.33%, 25.35%, or 25.38%. This invention, by limiting the content of Hf and Cr, can further improve the corrosion resistance of nickel-based alloys.

[0043] This invention improves the mechanical properties of nickel-based alloys by adding Zr and limiting the content of Zr and B while reducing the content of N and Nb+Ta; it further improves the mechanical properties of nickel-based alloys by adding Hf and limiting the content of Hf and Cr; it further improves the mechanical properties of nickel-based alloys by limiting the total content of Al and Mo; and it further improves the corrosion resistance and high temperature resistance of N08120 nickel-based alloys by designing the alloy composition.

[0044] The present invention also provides a method for preparing the N08120 nickel-based high-temperature alloy steel ingot described in the above technical solution, comprising: The raw materials are smelted and cast sequentially to obtain N08120 nickel-based high-temperature alloy steel ingots.

[0045] The present invention does not have any special limitations on the source of the raw materials, and commercially available products known to those skilled in the art can be used.

[0046] This invention involves smelting and casting the raw materials sequentially to obtain N08120 nickel-based high-temperature alloy steel ingots.

[0047] This invention does not impose any specific limitations on the types of raw materials; adjustments can be made based on the actual required alloy composition.

[0048] The present invention does not impose any special limitations on the smelting operation, and any smelting operation known to those skilled in the art can be used.

[0049] The present invention does not impose any special limitations on the pouring operation; any operation known to those skilled in the art can be used.

[0050] The preparation method provided by this invention is simple and suitable for industrial production.

[0051] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0052] Example 1 The chemical composition of an N08120 nickel-based high-temperature alloy steel ingot, by mass percentage, is as follows: Ni 36.5%, Cr 25.3%, C 0.02%, Si 0.48%, Mn 0.60%, P 0.015%, S 0.004%, Cu 0.20%, Al 0.02%, Ti 0.05%, Nb+Ta 0.10%, Mo 0.68%, W 0.01%, Co 1.0%, N 0.15%, B 0.005%, O 10ppm, H 1.0ppm, Nb 0.60%, Zr 0.001%, Hf 0.01%, and the balance Fe; The mass ratio of Nb to Ta is 1:1; The total mass percentage of B and Zr is 0.006%; The total mass percentage of Al and Mo is 0.70%; The total mass percentage of Hf and Cr is 25.31%; The preparation method of the N08120 nickel-based high-temperature alloy steel ingot is as follows: According to the required alloy composition, the raw materials are smelted and cast in sequence to obtain N08120 nickel-based high-temperature alloy steel ingot.

[0053] Comparative Example 1 Based on Example 1, the mass percentage of B was modified to 0.002%, the mass percentage of Zr was modified to 0.005%, the total mass percentage of B and Zr was 0.007%, and Fe was made up to 100%, while other conditions remained unchanged.

[0054] Comparative Example 2 Based on Example 1, the mass percentage of B was modified to 0.002%, the total mass percentage of B and Zr was 0.003%, Fe was added to make up 100%, and other conditions remained unchanged.

[0055] Example 2 Based on Example 1, the mass percentage of B was modified to 0.002%, the mass percentage of Zr was modified to 0.002%, the total mass percentage of B and Zr was 0.004%, and Fe was added to make up 100%, while other conditions remained unchanged.

[0056] The N08120 nickel-based high-temperature alloy steel ingots prepared in Examples 1-2 and Comparative Examples 1-2 were used to prepare forgings, and then room temperature and high temperature strength tests were conducted. The results are shown in Table 1. Among them, the room temperature tensile test used a standard Φ5mm specimen and a WE-300 tensile testing machine at a test temperature of 25℃ to determine the tensile strength, yield strength and elongation. Ultrasonic testing was performed according to the requirements of NB / T47013 quality grade 2. The grain size of the forging was ≤5. The intergranular corrosion rate (mm / a) was tested according to the ASTM G28A method.

[0057] The method for preparing forgings involves sequentially forging, annealing, rough machining, solution treatment, and aging treatment of N08120 nickel-based high-temperature alloy steel ingots to obtain forgings. The initial forging temperature is 1200℃, the final forging temperature is 1000℃, the forging ratio is 3.0, the elongation ratio is 2.0, and the total ratio is 4.0. The annealing holding temperature is 700℃, the holding time is 15 hours, and the cooling method is air cooling. The solution treatment holding temperature is 1200℃, the holding time is 1 hour, and the cooling method is air cooling. The aging treatment holding temperature is 800℃, the holding time is 3 hours, and the cooling method is air cooling.

[0058] Table 1. Mechanical properties of forgings made from N08120 nickel-based superalloy steel ingots of Examples 1-2 and Comparative Examples 1-2

[0059] As can be seen from Table 1, the present invention can improve the mechanical properties of N08120 nickel-based alloy by controlling the content of Zr and B, while changing the content of both will lead to a decrease in mechanical properties.

[0060] Comparative Example 3 Based on Example 1, the mass percentage of Mo was modified to 0.50%, the total mass percentage of Al and Mo was 0.52%, and Fe was made up to 100%, while other conditions remained unchanged.

[0061] Comparative Example 4 Based on Example 1, the mass percentage of Al was modified to 0.08%, the mass percentage of Mo was modified to 0.70%, the total mass percentage of Al and Mo was 0.78%, and Fe was added to make up 100%, while other conditions remained unchanged.

[0062] Example 3 Based on Example 1, the mass percentage of Mo was modified to 0.53%, the total mass percentage of Al and Mo was 0.55%, and Fe was made up to 100%, while other conditions remained unchanged.

[0063] The N08120 nickel-based high-temperature alloy steel ingots prepared in Examples 1, 3, and Comparative Examples 3-4 were prepared into forgings according to the aforementioned method, and then room temperature and high temperature strength tests were performed. The results are shown in Table 2.

[0064] Table 2. Mechanical properties of forgings made from N08120 nickel-based superalloy steel ingots of Examples 1, 3, and Comparative Examples 3-4.

[0065] As can be seen from Table 2, the mechanical properties of N08120 nickel-based alloy can be improved by controlling the content of Al and Mo. Changing the content of Al and Mo will lead to a decrease in mechanical properties.

[0066] Comparative Example 5 Based on Example 1, the mass percentage of Cr was modified to 25.0%, the total mass percentage of Hf and Cr was 25.01%, and Fe was made up to 100%, while other conditions remained unchanged.

[0067] Comparative Example 6 Based on Example 1, the mass percentage of Cr was modified to 25.4%, the mass percentage of Hf was modified to 0.05%, the total mass percentage of Hf and Cr was 25.45%, and Fe was made up to 100%, while other conditions remained unchanged.

[0068] The N08120 nickel-based high-temperature alloy steel ingots prepared in Example 1 and Comparative Examples 5-6 were prepared into forgings according to the aforementioned method, and then room temperature and high temperature strength tests were performed. The results are shown in Table 3.

[0069] Table 3 Mechanical properties of forgings made from N08120 nickel-based superalloy steel ingots of Example 1 and Comparative Examples 5-6

[0070] As can be seen from Table 3, the present invention can improve the mechanical properties of N08120 nickel-based alloy by controlling the content of Hf and Cr, while changing the content of the two will lead to a decrease in mechanical properties.

[0071] Example 4 Based on Example 1, the mass ratio of Nb to Ta was changed to 1:2, while other conditions remained unchanged.

[0072] Example 5 Based on Example 1, the mass ratio of Nb to Ta was changed to 1:3, while other conditions remained unchanged.

[0073] The N08120 nickel-based high-temperature alloy steel ingots prepared in Examples 1 and 4-5 were forged into forgings according to the aforementioned method, and then subjected to room temperature and high temperature strength tests. The results are shown in Table 4.

[0074] Table 4. Mechanical properties of forgings made from N08120 nickel-based superalloy steel ingots of Examples 1 and 4-5.

[0075] As can be seen from Table 4, the mechanical properties of N08120 nickel-based alloy can be further improved by controlling the mass ratio of Nb and Ta in this invention.

[0076] Comparative Example 7 The chemical composition of an N08120 nickel-based high-temperature alloy steel ingot, by mass percentage, is as follows: Ni 35%, Cr 27%, C 0.10%, Si 1.00%, Mn 1.0%, P 0.040%, S 0.02%, Cu 0.40%, Al 0.30%, Ti 0.10%, Nb+Ta 0.60%, Mo 2.0%, W 2.0%, Co 2.0%, N 0.30%, B 0.010%, O 10ppm, H 1.0ppm, Nb 0.60%, Zr 0.001%, Hf 0.01%, and the balance Fe; The preparation method of the N08120 nickel-based high-temperature alloy steel ingot is as follows: According to the required alloy composition, the raw materials are smelted and cast in sequence to obtain N08120 nickel-based high-temperature alloy steel ingot.

[0077] Comparative Example 8 The chemical composition of an N08120 nickel-based high-temperature alloy steel ingot, by mass percentage, is as follows: Ni 39%, Cr 23%, C 0.09%, Si 0.6%, Mn 0.9%, P 0.040%, S 0.02%, Cu 0.30%, Al 0.20%, Ti 0.09%, Nb+Ta 0.50%, Mo 1.0%, W 1.0%, Co 1.5%, N 0.30%, B 0.009%, O 10ppm, H 1.0ppm, Nb 0.60%, Zr 0.001%, Hf 0.01%, and the balance Fe; The preparation method of the N08120 nickel-based high-temperature alloy steel ingot is as follows: According to the required alloy composition, the raw materials are smelted and cast in sequence to obtain N08120 nickel-based high-temperature alloy steel ingot.

[0078] The N08120 nickel-based high-temperature alloy steel ingots prepared in Example 1 and Comparative Examples 7-8 were prepared into forgings according to the aforementioned method, and then room temperature and high temperature strength tests were performed. The results are shown in Table 5.

[0079] Table 5 Mechanical properties of forgings made from nickel-based superalloy steel ingots of Example 1 and Comparative Examples 7-8

[0080] As can be seen from Table 5, chemical compositions outside the scope of this invention but within the ASTM B366 standard range lead to a decrease in the mechanical properties of N08120 nickel-based alloy, proving that this invention can further improve the mechanical properties of nickel-based alloys by designing the alloy composition.

[0081] Example 6 A N08120 nickel-based high-temperature alloy steel ingot, the chemical composition of which, by mass percentage, includes: Ni 38%, Cr 25.2%, C 0.05%, Si 0.40%, Mn 0.60%, P 0.015%, S 0.004%, Cu 0.10%, Al 0.08%, Ti 0.02%, Nb+Ta 0.30%, Mo 0.50%, W 0.08%, Co 0.85%, N 0.30%, B 0.002%, O 10ppm, H 1.1ppm, Nb 0.90%, Zr 0.004%, Hf 0.05%, and the balance Fe; The total mass percentage of B and Zr is 0.006%; The total mass percentage of Al and Mo is 0.58%; The total mass percentage of Hf and Cr is 25.25%; The preparation method of the N08120 nickel-based high-temperature alloy steel ingot is as follows: According to the required alloy composition, the raw materials are smelted and cast in sequence to obtain N08120 nickel-based high-temperature alloy steel ingot.

[0082] Example 7 A nickel-based high-temperature alloy steel ingot, N08120, has the following chemical composition by mass percentage: Ni 37.2%, Cr 25.3%, C 0.03%, Si 0.44%, Mn 0.65%, P 0.015%, S 0.004%, Cu 0.15%, Al 0.05%, Ti 0.04%, Nb+Ta 0.20%, Mo 0.60%, W 0.05%, Co 0.95%, N 0.26%, B 0.003%, O 10ppm, H 1.0ppm, Nb 0.75%, Zr 0.003%, Hf 0.03%, and the balance Fe; The total mass percentage of B and Zr is 0.006%; The total mass percentage of Al and Mo is 0.65%; The total mass percentage of Hf and Cr is 25.33%; The preparation method of the N08120 nickel-based high-temperature alloy steel ingot is as follows: According to the required alloy composition, the raw materials are smelted and cast in sequence to obtain N08120 nickel-based high-temperature alloy steel ingot.

[0083] The N08120 nickel-based high-temperature alloy steel ingots prepared in Examples 1 and 7-8 were prepared into forgings according to the aforementioned method, and then room temperature and high temperature strength tests were performed. The results are shown in Table 6.

[0084] Table 6. Mechanical properties of forgings made from nickel-based superalloy steel ingots of Examples 1 and 7-8

[0085] As can be seen from Table 6, the mechanical properties of N08120 nickel-based alloy can be further improved by designing the alloy composition.

[0086] As can be seen from the above embodiments and comparative examples, the forgings prepared from the N08120 nickel-based high-temperature alloy steel ingot provided by the present invention have excellent mechanical properties.

[0087] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An N08120 nickel-based high-temperature alloy steel ingot, the chemical composition of which, by mass percentage, comprises: Ni 36.5~38%, Cr 25.0~25.4%, C 0.02~0.05%, Si 0.40~0.48%, Mn 0.60~0.70%, P≤0.020%, S≤0.005%, Cu 0.10~0.20%, Al 0.02~0.08%, Ti 0.02~0.05%, Nb+Ta 0.10~0.30%, Mo 0.50~0.75%, W 0.01~0.08%, Co 0.85~1.0%, N 0.15~0.30%, B 0.002~0.005%, O≤10ppm, H≤1.2ppm, Nb 0.60~0.90%, Zr 0.001~0.005%, Hf 0.01~0.05%, and the balance Fe; The total mass percentage of B and Zr is 0.004% to 0.006%; The total mass percentage of Al and Mo is 0.55~0.70%; The total mass percentage of Hf and Cr is 25.2% to 25.4%.

2. The N08120 nickel-based high-temperature alloy steel ingot according to claim 1, characterized in that, The chemical composition, by mass percentage, includes: Ni 36.8~37.5%, Cr 25.1~25.3%, C 0.03~0.04%, Si 0.42~0.46%, Mn 0.62~0.68%, P≤0.020%, S≤0.005%, Cu 0.12~0.18%, Al 0.03~0.07%, Ti 0.03~0.04%, Nb+Ta 0.15~0.25%, Mo 0.55~0.70%, W 0.02~0.07%, Co 0.88~0.95%, N 0.20~0.25%, B 0.003~0.004%, O≤10ppm, H≤1.2ppm, Nb 0.65~0.85%, Zr 0.002~0.004%, Hf 0.02~0.04% and balance Fe.

3. The N08120 nickel-based high-temperature alloy steel ingot according to claim 2, characterized in that, The chemical composition, by mass percentage, includes: Ni 37.0~37.3%, Cr 25.2~25.3%, C 0.03~0.04%, Si 0.43~0.45%, Mn 0.64~0.66%, P≤0.020%, S≤0.005%, Cu 0.14~0.16%, Al 0.04~0.06%, Ti 0.03~0.04%, Nb+Ta 0.18~0.22%, Mo 0.60~0.65%, W 0.03~0.06%, Co 0.90~0.93%, N 0.21~0.24%, B 0.003~0.004%, O≤10ppm, H≤1.2ppm, Nb 0.70~0.80%, Zr 0.003~0.004%, Hf 0.03~0.04% and balance Fe.

4. The N08120 nickel-based high-temperature alloy steel ingot according to claim 1, characterized in that, The total mass percentage of B and Zr is 0.005~0.0055%.

5. The N08120 nickel-based high-temperature alloy steel ingot according to claim 4, characterized in that, The total mass percentage of B and Zr is 0.0052~0.0054%.

6. The N08120 nickel-based high-temperature alloy steel ingot according to claim 1, characterized in that, The total mass percentage of Al and Mo is 0.60~0.65%.

7. The N08120 nickel-based high-temperature alloy steel ingot according to claim 6, characterized in that, The total mass percentage of Al and Mo is 0.62~0.64%.

8. The N08120 nickel-based high-temperature alloy steel ingot according to claim 1, characterized in that, The total mass percentage of Hf and Cr is 25.25% to 25.35%.

9. The N08120 nickel-based high-temperature alloy steel ingot according to claim 8, characterized in that, The total mass percentage of Hf and Cr is 25.3%.

10. A method for preparing the N08120 nickel-based superalloy steel ingot according to any one of claims 1 to 9, comprising: The raw materials are smelted and cast sequentially to obtain N08120 nickel-based high-temperature alloy steel ingots.

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