Nickel-based high-temperature alloy with low cracking sensitivity coefficient, manufacturing method therefor and use thereof

Abstract

The present invention belongs to the technical field of alloys. Disclosed are a nickel-based high-temperature alloy with low cracking sensitivity coefficients, a manufacturing method therefor and the use thereof. The nickel-based high-temperature alloy comprises: 16.73-17.40% of Cr, 15.60-16.70% of Co, 0.00-0.01% of Mo, 5.90-6.30% of W, 1.80-2.12% of Ta, 1.40-1.62% of Nb, 1.90-2.10% of Al, 3.40-3.60% of Ti, 0.12-0.14% of C, 0.003-0.007% of B, 0.005-0.009% of Zr and the balance of Ni and inevitable impurity elements. The present invention obtains the nickel-based high-temperature alloy with low cracking sensitivity coefficients, high aluminum and titanium content, high Co+W solid solution strengthening element content and low oxygen content, and turbine blades made from the alloy by means of the additive manufacturing process exhibit high density, high creep strength and low oxygen content, thereby effectively meeting the technical requirements of high-power gas turbines.

Description

A nickel-based high-temperature alloy with low cracking sensitivity coefficient and its preparation method and use Technical Field

[0001] The present invention belongs to the technical field of alloys, and in particular relates to a nickel-based high-temperature alloy with a low cracking sensitivity coefficient and a high aluminum-titanium content, as well as a preparation method and application of the nickel-based high-temperature alloy. Background Art

[0002] Nickel-based alloys are the most widely used and have the highest high-temperature strength among high-temperature alloys. This is because:

[0003] 1. Nickel-based alloys can dissolve more alloying elements and maintain good structural stability;

[0004] 2. It can form coherent and ordered A3B type intermetallic compounds, with γ'[Ni3(Al,Ti)] phase as the strengthening phase, which effectively strengthens the alloy and obtains higher high temperature strength than iron-based and cobalt-based high temperature alloys;

[0005] 3. Nickel-based alloys containing chromium have better resistance to oxidation and gas corrosion than iron-based high-temperature alloys.

[0006] Therefore, nickel-based high-temperature alloys are widely used to manufacture high-temperature components such as turbine blades, guide blades, turbine discs, high-pressure compressor discs and combustion chambers for aviation, shipbuilding and industrial gas turbines.

[0007] In recent years, as gas turbine efficiency has steadily increased, the structural design of turbine blades has become increasingly complex. This complexity primarily manifests itself in the design of the cooling channels within the turbine blades, which increases the technical difficulty of the casting process, sometimes even making it impossible to achieve. The recent rise of laser additive manufacturing (AM) reliably addresses the technical limitations of traditional casting for turbine blades.

[0008] Gas turbines with high power efficiency require turbine blades with high creep strength. Due to the special characteristics of the above-mentioned nickel-based superalloys, turbine blades with high creep strength require nickel-based superalloys with high aluminum and titanium content to be formed, so that the formed turbine blades have an internal structure with a high content of γ' strengthening phase. However, paradoxically, nickel-based superalloys with high aluminum and titanium content have poor weldability and are prone to cracking during the welding process. Therefore, in the laser additive manufacturing process, the high aluminum and titanium content nickel-based superalloy powder will produce thermal cracking during the melting process under the action of the laser heat source, resulting in a large number of microcracks in the internal structure of the printed parts, which cannot meet the technical requirements of the design working condition performance. Therefore, it can be seen that the blind pursuit of high aluminum and titanium content in nickel-based superalloys will inevitably lead to the technical problem of microcracks that affect the molding quality of the laser additive manufacturing process.

[0009] This technical issue has also resonated with the industry. The industry uses the crack sensitivity of nickel-based high-temperature alloys as the basis for judgment to develop nickel-based high-temperature alloy materials with low crack sensitivity but high aluminum and titanium content. For example, the Chinese patent documents disclose the names of "A nickel-based high-temperature alloy for 3D printing and its powder preparation method" (publication number CN 111996414 A, publication date November 27, 2020), "A precipitation-hardening nickel-based high-temperature alloy for high-plasticity additive manufacturing and its design and preparation method" (publication number CN 116377286 A, publication date July 4, 2023) and other technologies. However, these developed nickel-based high-temperature alloy materials contain easily oxidized elements such as Y, La, Ce, and Mg. Specifically, the technology disclosed in Publication No. CN 111996414 A contains easily oxidized elements Y, La, and Ce, while the technology disclosed in Publication No. CN 116377286 A contains easily oxidized elements Mg. This results in a high oxygen content in the material and the amount of oxygen added during the laser additive manufacturing process. This is not conducive to reliably improving the creep strength of the molded components, and the resulting turbine blades have poor performance when used in high-efficiency gas turbines.

[0010] Based on this, in order to obtain turbine blades with high creep strength, it is necessary to improve nickel-based high-temperature alloy materials to obtain nickel-based high-temperature alloy materials with low cracking sensitivity coefficient, high aluminum and titanium content, and low oxygen content.

[0011] Summary of the Invention

[0012] The technical purpose of the present invention is to provide a nickel-based high-temperature alloy with a low crack sensitivity coefficient, high aluminum and titanium content, and low oxygen content, as well as a preparation method and use of the nickel-based high-temperature alloy, in view of the particularity of the above-mentioned nickel-based high-temperature alloy and the technical requirements of high-power gas turbines for high creep strength turbine blades.

[0013] In order to achieve the above technical objectives, the technical solution adopted by the present invention is a nickel-based high-temperature alloy with a low cracking sensitivity coefficient, wherein the nickel-based high-temperature alloy contains the following alloying elements in the following mass percentages:

[0014] Cr 16.73~17.40%, Co 15.60~16.70%, W 5.90~6.30%, Ta 1.80~2.12%, Nb 1.40~1.62%, Al 1.90~2.10%, Ti 3.40~3.60%, C 0.12~0.14%, B 0.003~0.007%, Zr 0.005~0.009%, balance Ni and inevitable impurity elements; balance Ni and inevitable impurity elements.

[0015] Furthermore, the nickel-based high-temperature alloy further contains Mo element; the maximum mass percentage of the Mo element in the nickel-based high-temperature alloy is 0.01%.

[0016] As one of the preferred options, the nickel-based high-temperature alloy contains the following alloying elements in percentage by mass: Cr 17.24%, Co 16.67%, Mo 0.01%, W 6.09%, Ta 1.95%, Nb 1.47%, Al 2.04%, Ti 3.60%, C 0.14%, B 0.003%, Zr 0.009%, and the balance is Ni and unavoidable impurity elements.

[0017] As one of the preferred options, the nickel-based high-temperature alloy contains the following alloying elements in percentage by mass: Cr 16.73%, Co 15.60%, Mo 0.005%, W 5.92%, Ta 2.12%, Nb 1.45%, Al 2.00%, Ti 3.54%, C 0.12%, B 0.005%, Zr 0.007%, and the balance is Ni and unavoidable impurity elements.

[0018] As one of the preferred options, the nickel-based high-temperature alloy contains the following alloying elements in percentage by mass: Cr 16.90%, Co 15.86%, Mo 0.009%, W 6.29%, Ta 1.93%, Nb 1.58%, Al 2.02%, Ti 3.54%, C 0.14%, B 0.005%, Zr 0.005%, and the balance is Ni and unavoidable impurity elements.

[0019] As one of the preferred solutions, the nickel-based high-temperature alloy contains the following alloying elements in percentage by mass: Cr 17.40%, Co 16.70%, Mo 0.008%, W 6.00%, Ta 1.99%, Nb 1.62%, Al 2.10%, Ti 3.49%, C 0.14%, B 0.007%, Zr 0.006%, and the balance is Ni and unavoidable impurity elements.

[0020] As one of the preferred options, the nickel-based high-temperature alloy contains the following alloying elements in percentage by mass: Cr 17.14%, Co 15.70%, Mo 0.01%, W 6.00%, Ta 1.99%, Nb 1.45%, Al 2.02%, Ti 3.52%, C 0.14%, B 0.005%, Zr 0.007%, and the balance is Ni and unavoidable impurity elements.

[0021] The applicant's research found that the cracking sensitivity of nickel-based high-temperature alloy materials is mainly considered by the cracking time during the liquid phase solidification process and the time used in the stress relief process. The cracking sensitivity coefficient can be expressed as the ratio between the two. The solidification process comprehensively considers parameters such as solidification rate, time, and phase change. Therefore, the cracking sensitivity coefficient can be obtained by non-equilibrium thermodynamic calculation. Based on the crack sensitivity of nickel-based high-temperature alloy materials as the basis for evaluation, nickel-based high-temperature alloy materials with low crack sensitivity but high aluminum and titanium content have been developed.

[0022] The nickel-based superalloy material obtained by the above-mentioned technical measures has an alloy solidification crack sensitivity coefficient calculated by Thermo-Calc software to be below 0.3, which is much lower than that of traditional high-aluminum-titanium nickel-based superalloy materials, such as the nickel-based superalloy materials with grades IN738LC (1.11) and Mar-M247 (1.08). Reducing the crack sensitivity coefficient can ensure that solidification cracks are effectively controlled during the melting process of the laser additive manufacturing process.

[0023] These technical measures differ from the traditional practice of simply evaluating a material's printability in laser additive manufacturing based on its Al and Ti content. Instead, they comprehensively consider the contributions of all elements to the crack sensitivity coefficient during solidification, ensuring maximum Al and Ti additions and the maximum precipitation of γ' phase in the resulting material, thereby optimizing high-temperature performance and improving the creep strength of the molded parts. Furthermore, while maintaining a high Al and Ti content, these measures boast a higher content of Co+W solid-solution strengthening elements than nickel-based superalloys such as IN738LC and Mar-M247, ensuring the alloy possesses excellent high-temperature creep resistance. Furthermore, these measures do not contain easily oxidizable elements such as Hf, La, Ce, Y, and Mg, minimizing the oxygen content of the powder and the oxygen increment during the additive process.

[0024] Therefore, the above technical measures are aimed at the particularity of the above-mentioned nickel-based high-temperature alloys and the technical requirements of high-power-efficiency gas turbines for high creep strength turbine blades, and have obtained nickel-based high-temperature alloy materials with the technical characteristics of low cracking sensitivity coefficient, high aluminum and titanium content, high Co+W solid solution strengthening element content, and low oxygen content, which effectively meet the technical requirements of high creep strength turbine blades required by high-power-efficiency gas turbines through laser additive manufacturing process.

[0025] A method for preparing the above-mentioned nickel-based high-temperature alloy with low cracking sensitivity coefficient, the preparation method comprising the following process steps:

[0026] Step 1. Add the formulated amount of alloying elements into a crucible, place the crucible in a vacuum induction furnace, use induction heating at a vacuum degree below 0.1 Pa, raise the temperature to 1550°C-1700°C, and perform high-temperature vacuum melting for 20min-40min;

[0027] Step 2. Place the alloy ingot into a vacuum consumable arc furnace as a consumable electrode, make the vacuum degree in the furnace lower than 0.3 Pa, turn on the power to form an arc, perform vacuum consumable remelting on the alloy ingot, and cool naturally to obtain a vacuum consumable alloy billet without secondary shrinkage cavity in the center;

[0028] Step 3. Place the alloy rod blank into the plasma rotating electrode powder making equipment, evacuate the powder making chamber to below 0.1 Pa, and fill the powder making chamber with 0.7MPa-0.9MPa of He and Ar mixed gas; the plasma gun current is 1100A-1500A, the voltage is 50V-65V, the rotation speed of the alloy rod blank is 14000r / min-18000r / min, and the distance between the plasma gun and the alloy rod is 30mm-50mm. The end of the ultra-high-speed rotating alloy rod is melted into a liquid film under the action of the coaxial plasma arc heating source, and is thrown toward the outer edge of the electrode end under the action of centrifugal force, broken into balls in the air and rapidly solidified, and finally falls into the powder collector below the powder making chamber to obtain spherical powder of nickel-based high-temperature alloy.

[0029] The above technical measures utilize a nickel-based superalloy material with a low crack sensitivity coefficient, high aluminum and titanium content, high Co+W solid solution strengthening element content, and low oxygen content, through vacuum consumable remelting. This further reduces the content of impurity elements, increases alloy purity, and reduces the content of trace elements enriched at grain boundaries. This further enhances the alloy's crack resistance, eliminates secondary shrinkage cavities in the center, and achieves a dense, high-density nickel-based superalloy. The resulting nickel-based superalloy material boasts high purity, good density, and excellent crack resistance.

[0030] One application of the low-cracking-susceptibility nickel-based superalloy spherical powder produced by the aforementioned preparation method involves screening the powder from the nickel-based superalloy spherical powder to select a powder with a particle size of 15 to 53 μm in a high-purity argon atmosphere. This powder is then used as raw material for forming high-temperature turbine blades for gas turbines using a laser additive manufacturing process. The resulting turbine blades exhibit excellent density, high creep strength, and low oxygen content (the increase in impurity oxygen is less than 80 ppm), effectively meeting the technical requirements of high-power gas turbines.

[0031] The beneficial technical effect of the present invention is: the above-mentioned technical measures are aimed at the particularity of the above-mentioned nickel-based high-temperature alloy and the technical requirements of high-power gas turbines for high creep strength turbine blades, and a nickel-based high-temperature alloy material with technical characteristics of low cracking sensitivity coefficient, high aluminum and titanium content, high Co+W solid solution strengthening element content, and low oxygen content (the increase in impurity element oxygen is less than 80ppm) is obtained. The turbine blades formed by the nickel-based high-temperature alloy material through the laser additive manufacturing process have good density, high creep strength, and low oxygen content, which effectively meet the technical requirements of high-power gas turbines. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The present invention will now be described by way of example with reference to the accompanying drawings, in which:

[0033] FIG1 is a morphology diagram of the powder of the present invention prepared by the ultra-high-speed rotating electrode method in Example 1.

[0034] FIG2 is a comparison chart of the cracking sensitivity coefficients of the nickel-based high-temperature alloy materials obtained in Examples 1 to 5 and commercially available nickel-based high-temperature alloy materials.

[0035] FIG3 is a microscopic metallographic image of the nickel-based high-temperature alloy material obtained in Example 1, obtained by laser additive manufacturing process.

[0036] FIG4 is a microstructure diagram of the nickel-based high-temperature alloy material obtained in Example 1 obtained by laser additive manufacturing process. DETAILED DESCRIPTION

[0037] All features disclosed in this specification, or all steps in the disclosed methods or processes, except mutually exclusive features and / or steps, can be combined in any manner.

[0038] Any feature disclosed in this specification, unless otherwise stated, may be replaced by other equivalent or similar features. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

[0039] The present invention belongs to the field of alloy technology, and specifically relates to a nickel-based high-temperature alloy with a low cracking sensitivity coefficient and a high aluminum-titanium content, as well as a preparation method and use of the nickel-based high-temperature alloy. The main technical solution of the present invention is specifically described below with reference to multiple embodiments.

[0040] Example 1

[0041] The nickel-based high-temperature alloy material of the present invention is used for forming high-temperature turbine blades for gas turbines using a laser additive manufacturing process, and specifically contains the following alloying elements in the following mass percentages (the purity of each element is not less than 99.99%): 17.24% Cr, 16.67% Co, 0.01% Mo, 6.09% W, 1.95% Ta, 1.47% Nb, 2.04% Al, 3.60% Ti, 0.14% C, 0.003% B, 0.009% Zr, and the balance is Ni and unavoidable impurity elements.

[0042] The nickel-based high-temperature alloy material with the above formula is made into spherical powder for laser additive manufacturing process. The specific preparation method includes the following process steps:

[0043] Step 1. Add the formulated amount of alloying elements into a crucible, place the crucible in a vacuum induction furnace, use induction heating at a vacuum degree below 0.1 Pa, raise the temperature to 1680°C and perform high-temperature vacuum melting for 25 minutes;

[0044] The vacuum induction furnace is closed and casting is performed at 1600°C to form an alloy ingot;

[0045] Step 2. Place the alloy ingot into a vacuum consumable arc furnace as a consumable electrode, make the vacuum degree in the furnace lower than 0.3 Pa, turn on the power to form an arc, perform vacuum consumable remelting on the alloy ingot, and cool naturally to obtain a vacuum consumable alloy billet without secondary shrinkage cavity in the center;

[0046] Step 3. Place the alloy rod into the plasma rotating electrode powder making equipment, evacuate the powder making chamber to below 0.1 Pa, and fill the powder making chamber with a He and Ar mixed gas at 0.8 MPa;

[0047] The plasma gun current is 1400A, the voltage is 55V, the rotation speed of the alloy rod is 17000r / min, and the distance between the plasma gun and the alloy rod is 40mm. The end of the ultra-high-speed rotating alloy rod is melted into a liquid film under the action of the coaxial plasma arc heating source. It is thrown toward the outer edge of the electrode end under the action of centrifugal force, broken into balls in the air and quickly solidified, and finally fell into the powder collector below the powder making chamber to obtain the nickel-based high-temperature alloy spherical powder shown in Figure 1;

[0048] Step 4. Under a high-purity argon atmosphere, a powder with a particle size range of 15 to 53 μm is screened from the nickel-based high-temperature alloy spherical powder, and the powder is used as a raw material for the laser additive manufacturing process.

[0049] The nickel-based high-temperature alloy powder (designated DFNC-1) produced in this embodiment was tested to have a weld opening crack sensitivity of 0.16443, as compared with the cracking sensitivity coefficient of commercially available nickel-based high-temperature alloy materials as shown in FIG2 . The microstructured metallographic images of the components obtained by laser additive manufacturing are shown in FIG3 and FIG4 , indicating that selective melting and solidification cracks can be effectively controlled during the laser additive manufacturing process.

[0050] Example 2

[0051] The nickel-based high-temperature alloy material of the present invention is used for forming high-temperature turbine blades for gas turbines using a laser additive manufacturing process, and specifically contains the following alloying elements in the following mass percentages (the purity of each element is not less than 99.99%): 16.73% Cr, 15.60% Co, 0.005% Mo, 5.92% W, 2.12% Ta, 1.45% Nb, 2.00% Al, 3.54% Ti, 0.12% C, 0.005% B, 0.007% Zr, and the balance is Ni and unavoidable impurity elements.

[0052] The nickel-based high-temperature alloy material with the above formula is made into spherical powder for laser additive manufacturing process. The specific preparation method includes the following process steps:

[0053] Step 1. Add the formulated amount of alloying elements into a crucible, place the crucible in a vacuum induction furnace, use induction heating at a vacuum degree below 0.1 Pa, raise the temperature to 1550°C and perform high-temperature vacuum melting for 40 minutes;

[0054] The vacuum induction furnace is closed and casting is performed at 1500°C to form an alloy ingot;

[0055] Step 2. Place the alloy ingot into a vacuum consumable arc furnace as a consumable electrode, make the vacuum degree in the furnace lower than 0.3 Pa, turn on the power to form an arc, perform vacuum consumable remelting on the alloy ingot, and cool naturally to obtain a vacuum consumable alloy billet without secondary shrinkage cavity in the center;

[0056] Step 3. Place the alloy rod into the plasma rotating electrode powder making equipment, evacuate the powder making chamber to below 0.1 Pa, and fill the powder making chamber with a He and Ar mixed gas at 0.7 MPa;

[0057] The plasma gun has a current of 1100A and a voltage of 50V. The alloy rod billet rotates at a speed of 18,000 rpm and a distance of 30mm between the plasma gun and the alloy rod. The end of the ultra-high-speed rotating alloy rod melts into a liquid film under the action of a coaxial plasma arc heating source. The liquid film is then thrown toward the outer edge of the electrode under the action of centrifugal force. It breaks into balls in the air and quickly solidifies. It eventually falls into the powder collector below the powder making chamber to obtain spherical nickel-based high-temperature alloy powder.

[0058] Step 4. Under a high-purity argon atmosphere, a powder with a particle size range of 15 to 53 μm is screened from the nickel-based high-temperature alloy spherical powder, and the powder is used as a raw material for the laser additive manufacturing process.

[0059] The nickel-based high-temperature alloy powder (designated DFNC-2) prepared in this embodiment was tested and found to have a weld opening crack sensitivity of 0.19778. A comparison of the cracking sensitivity coefficient of commercially available nickel-based high-temperature alloy materials is shown in FIG2 . This indicates that selective melting and solidification cracking can be effectively controlled during the laser additive manufacturing process.

[0060] Example 3

[0061] The nickel-based high-temperature alloy material of the present invention is used for forming high-temperature turbine blades for gas turbines using a laser additive manufacturing process, and specifically contains the following alloying elements in the following mass percentages (the purity of each element is not less than 99.99%): 16.90% Cr, 15.86% Co, 0.009% Mo, 6.29% W, 1.93% Ta, 1.58% Nb, 2.02% Al, 3.54% Ti, 0.14% C, 0.005% B, 0.005% Zr, and the balance is Ni and unavoidable impurity elements.

[0062] The nickel-based high-temperature alloy material with the above formula is made into spherical powder for laser additive manufacturing process. The specific preparation method includes the following process steps:

[0063] Step 1. Add the formulated amount of alloying elements into a crucible, place the crucible in a vacuum induction furnace, use induction heating at a vacuum degree below 0.1 Pa, raise the temperature to 1700°C and perform high-temperature vacuum melting for 20 minutes;

[0064] The vacuum induction furnace was closed and casting was performed at 1620°C to form an alloy ingot;

[0065] Step 2. Place the alloy ingot into a vacuum consumable arc furnace as a consumable electrode, make the vacuum degree in the furnace lower than 0.3 Pa, turn on the power to form an arc, perform vacuum consumable remelting on the alloy ingot, and cool naturally to obtain a vacuum consumable alloy billet without secondary shrinkage cavity in the center;

[0066] Step 3. Place the alloy rod into the plasma rotating electrode powder making equipment, evacuate the powder making chamber to below 0.1 Pa, and fill the powder making chamber with a He and Ar mixed gas of 0.9 MPa;

[0067] The plasma gun has a current of 1500A and a voltage of 65V. The alloy rod billet rotates at a speed of 14000r / min. The distance between the plasma gun and the alloy rod is 50mm. The end of the ultra-high-speed rotating alloy rod is melted into a liquid film under the action of a coaxial plasma arc heating source. The liquid film is then thrown toward the outer edge of the electrode under the action of centrifugal force. It breaks into balls in the air and quickly solidifies. It eventually falls into the powder collector below the powder making chamber to obtain spherical nickel-based high-temperature alloy powder.

[0068] Step 4. Under a high-purity argon atmosphere, a powder with a particle size range of 15 to 53 μm is screened from the nickel-based high-temperature alloy spherical powder, and the powder is used as a raw material for the laser additive manufacturing process.

[0069] The nickel-based high-temperature alloy powder (designated DFNC-3) prepared in this embodiment was tested and found to have a weld opening crack sensitivity of 0.17461. A comparison of the cracking sensitivity coefficient of commercially available nickel-based high-temperature alloy materials is shown in FIG2 . This indicates that selective melting and solidification cracking can be effectively controlled during the laser additive manufacturing process.

[0070] Example 4

[0071] The nickel-based high-temperature alloy material of the present invention is used for forming high-temperature turbine blades for gas turbines using a laser additive manufacturing process, and specifically contains the following alloying elements in the following mass percentages (the purity of each element is not less than 99.99%): 17.40% Cr, 16.70% Co, 0.008% Mo, 6.00% W, 1.99% Ta, 1.62% Nb, 2.10% Al, 3.49% Ti, 0.14% C, 0.007% B, 0.006% Zr, and the balance is Ni and unavoidable impurity elements.

[0072] The nickel-based high-temperature alloy material with the above formula is made into spherical powder for laser additive manufacturing process. The specific preparation method includes the following process steps:

[0073] Step 1. Add the formulated amount of alloying elements into a crucible, place the crucible in a vacuum induction furnace, use induction heating at a vacuum degree below 0.1 Pa, raise the temperature to 1600°C and perform high-temperature vacuum melting for 35 minutes;

[0074] The vacuum induction furnace was closed and casting was performed at 1550°C to form an alloy ingot;

[0075] Step 2. Place the alloy ingot into a vacuum consumable arc furnace as a consumable electrode, make the vacuum degree in the furnace lower than 0.3 Pa, turn on the power to form an arc, perform vacuum consumable remelting on the alloy ingot, and cool naturally to obtain a vacuum consumable alloy billet without secondary shrinkage cavity in the center;

[0076] Step 3. Place the alloy rod into the plasma rotating electrode powder making equipment, evacuate the powder making chamber to below 0.1 Pa, and fill the powder making chamber with a He and Ar mixed gas at 0.8 MPa;

[0077] The plasma gun has a current of 1300A and a voltage of 60V. The alloy rod billet rotates at a speed of 16,000 rpm. The distance between the plasma gun and the alloy rod is 40mm. The end of the ultra-high-speed rotating alloy rod is melted into a liquid film under the action of a coaxial plasma arc heating source. The liquid film is then thrown toward the outer edge of the electrode under the action of centrifugal force. It breaks into balls in the air and quickly solidifies. It eventually falls into the powder collector below the powder making chamber to obtain spherical nickel-based high-temperature alloy powder.

[0078] Step 4. Under a high-purity argon atmosphere, a powder with a particle size range of 15 to 53 μm is screened from the nickel-based high-temperature alloy spherical powder, and the powder is used as a raw material for the laser additive manufacturing process.

[0079] The nickel-based high-temperature alloy powder (designated DFNC-4) prepared in this embodiment was tested and found to have a weld opening crack sensitivity of 0.07958. A comparison of the cracking sensitivity coefficient of commercially available nickel-based high-temperature alloy materials is shown in FIG2 . This indicates that selective melting and solidification cracking can be effectively controlled during the laser additive manufacturing process.

[0080] Example 5

[0081] The nickel-based high-temperature alloy material of the present invention is used for forming high-temperature turbine blades for gas turbines using a laser additive manufacturing process, and specifically contains the following alloying elements in the following mass percentages (the purity of each element is not less than 99.99%): 17.14% Cr, 15.70% Co, 0.01% Mo, 6.00% W, 1.99% Ta, 1.45% Nb, 2.02% Al, 3.52% Ti, 0.14% C, 0.005% B, 0.007% Zr, and the balance is Ni and unavoidable impurity elements.

[0082] The nickel-based high-temperature alloy material with the above formula is made into spherical powder for laser additive manufacturing process. The specific preparation method includes the following process steps:

[0083] Step 1. Add the formulated amount of alloying elements into a crucible, place the crucible in a vacuum induction furnace, use induction heating at a vacuum degree below 0.1 Pa, raise the temperature to 1700°C and perform high-temperature vacuum melting for 35 minutes;

[0084] The vacuum induction furnace is closed and casting is performed at 1600°C to form an alloy ingot;

[0085] Step 2. Place the alloy ingot into a vacuum consumable arc furnace as a consumable electrode, make the vacuum degree in the furnace lower than 0.3 Pa, turn on the power to form an arc, perform vacuum consumable remelting on the alloy ingot, and cool naturally to obtain a vacuum consumable alloy billet without secondary shrinkage cavity in the center;

[0086] Step 3. Place the alloy rod into the plasma rotating electrode powder making equipment, evacuate the powder making chamber to below 0.1 Pa, and fill the powder making chamber with a He and Ar mixed gas of 0.9 MPa;

[0087] The plasma gun has a current of 1400A and a voltage of 50V. The alloy rod billet rotates at a speed of 17000r / min. The distance between the plasma gun and the alloy rod is 45mm. The end of the ultra-high-speed rotating alloy rod is melted into a liquid film under the action of a coaxial plasma arc heating source. The liquid film is then thrown toward the outer edge of the electrode under the action of centrifugal force. It breaks into balls in the air and quickly solidifies. It eventually falls into the powder collector below the powder making chamber to obtain spherical nickel-based high-temperature alloy powder.

[0088] Step 4. Under a high-purity argon atmosphere, a powder with a particle size range of 15 to 53 μm is screened from the nickel-based high-temperature alloy spherical powder, and the powder is used as a raw material for the laser additive manufacturing process.

[0089] The nickel-based high-temperature alloy powder (designated DFNC-5) prepared in this embodiment was tested and found to have a weld opening crack sensitivity of 0.08387. A comparison of the cracking sensitivity coefficient with commercial nickel-based high-temperature alloy materials on the market is shown in FIG2 . This indicates that selective melting and solidification cracking can be effectively controlled during the laser additive manufacturing process.

[0090] Example 6

[0091] The nickel-based high-temperature alloy material of the present invention specifically contains the following alloying elements in percentage by mass (the purity of each element is not less than 99.99%): 16.80% Cr, 16.45% Co, 6.10% W, 1.80% Ta, 1.40Nb, 1.90% Al, 3.40Ti, 0.13% C, 0.006% B, 0.008% Zr, and the balance is Ni and unavoidable impurity elements.

[0092] The nickel-based high-temperature alloy material with the above formula is used for forming turbine blades of a gas turbine by a traditional casting method.

[0093] The above embodiments are only used to illustrate the present invention, rather than to limit it.

[0094] The present invention is not limited to the aforementioned specific embodiments, but extends to any new features or any new combination disclosed in this specification, as well as any new method or process steps or any new combination disclosed.

Claims

1. A nickel-based high-temperature alloy with low cracking sensitivity, characterized in that: The nickel-based high-temperature alloy contains the following alloy elements in percentage by mass: Cr 16.73-17.40%, Co 15.60-16.70%, W 5.90-6.30%, Ta 1.80-2.12%, Nb 1.40-1.62%, Al 1.90-2.10%, Ti 3.40-3.60%, C 0.12-0.14%, B 0.003-0.007%, Zr 0.005-0.009%, and the balance is Ni and unavoidable impurity elements.

2. The nickel-based high-temperature alloy with low crack sensitivity according to claim 1, characterized in that: The nickel-based high-temperature alloy further contains Mo element; the maximum mass percentage of the Mo element in the nickel-based high-temperature alloy is 0.01%.

3. The nickel-based high-temperature alloy with low cracking sensitivity according to claim 2, characterized in that: The nickel-based high-temperature alloy contains the following alloy elements in percentage by mass: Cr 17.24%, Co 16.67%, Mo 0.01%, W 6.09%, Ta 1.95%, Nb 1.47%, Al 2.04%, Ti 3.60%, C 0.14%, B 0.003%, Zr 0.009%, and the balance is Ni and unavoidable impurity elements.

4. The nickel-based high-temperature alloy with low crack sensitivity according to claim 2, characterized in that: The nickel-based high-temperature alloy contains the following alloy elements in percentage by mass: Cr 16.73%, Co 15.60%, Mo 0.005%, W 5.92%, Ta 2.12%, Nb 1.45%, Al 2.00%, Ti 3.54%, C 0.12%, B 0.005%, Zr 0.007%, and the balance is Ni and unavoidable impurity elements.

5. The nickel-based high-temperature alloy with low crack sensitivity according to claim 2, characterized in that: The nickel-based high-temperature alloy contains the following alloy elements in percentage by mass: Cr 16.90%, Co 15.86%, Mo 0.009%, W 6.29%, Ta 1.93%, Nb 1.58%, Al 2.02%, Ti 3.54%, C 0.14%, B 0.005%, Zr 0.005%, and the balance is Ni and unavoidable impurity elements.

6. The nickel-based high-temperature alloy with low crack sensitivity according to claim 2, characterized in that: The nickel-based high-temperature alloy contains the following alloy elements in percentage by mass: Cr 17.40%, Co 16.70%, Mo 0.008%, W 6.00%, Ta 1.99%, Nb 1.62%, Al 2.10%, Ti 3.49%, C 0.14%, B 0.007%, Zr 0.006%, and the balance is Ni and unavoidable impurity elements.

7. The nickel-based high-temperature alloy with low crack sensitivity according to claim 2, characterized in that: The nickel-based high-temperature alloy contains the following alloy elements in percentage by mass: Cr 17.14%, Co 15.70%, Mo 0.01%, W 6.00%, Ta 1.99%, Nb 1.45%, Al 2.02%, Ti 3.52%, C 0.14%, B 0.005%, Zr 0.007%, and the balance is Ni and unavoidable impurity elements.

8. A method for preparing the nickel-based high-temperature alloy with low cracking sensitivity coefficient according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following process steps: Step 1. Smelting the alloy elements in the formula into alloy ingots in a vacuum induction furnace; Step 2. The alloy ingot is remelted in a vacuum consumable manner to form an alloy billet having no secondary shrinkage cavity in the center; Step 3. The alloy rod blank is made into nickel-based high-temperature alloy spherical powder through an ultra-high-speed rotating electrode.

9. The preparation method according to claim 8, characterized in that: In step 1, the vacuum degree of the vacuum induction furnace is lower than 0.1Pa.

10. The preparation method according to claim 8, characterized in that: In step 1, the alloy is smelted in a vacuum furnace at a smelting temperature of 1550° C. to 1700° C. and a smelting time of 20 min to 40 min.

11. The preparation method according to claim 8, characterized in that: In step 1, after smelting, pouring is performed at 1500° C.-1620° C. to form an alloy ingot.

12. The preparation method according to claim 8, characterized in that: In step 2, a vacuum consumable arc furnace is used to perform vacuum consumable remelting, and the vacuum degree of the vacuum consumable remelting is lower than 0.3Pa.

13. The preparation method according to claim 8, characterized in that: In step 2, the alloy rod is formed by vacuum consumable remelting and natural cooling.

14. The preparation method according to claim 8, characterized in that: In step 3, a plasma rotating electrode powder making device is used to prepare nickel-based high-temperature alloy spherical powder.

15. The preparation method according to claim 14, characterized in that: The powder making chamber in the plasma rotating electrode powder making equipment was evacuated to below 0.1 Pa, and a mixed gas of He and Ar at 0.9 MPa was filled into the powder making chamber.

16. The preparation method according to claim 14, characterized in that: The current of the plasma gun is 1100A-1500A, the voltage is 50V-65V, the rotation speed of the alloy billet is 14000r / min-18000r / min, and the distance between the plasma gun and the alloy billet is 30mm-50mm.

17. Use of a spherical powder of a nickel-based high-temperature alloy with low cracking sensitivity coefficient obtained by the method for preparing a nickel-based high-temperature alloy with low cracking sensitivity coefficient according to any one of claims 8 to 16, characterized in that: Used as raw material for high-temperature turbine blades of gas turbines formed by laser additive manufacturing process.

18. The use according to claim 17, characterized in that The raw material is powder with a particle size of 15 to 53 μm selected from nickel-based high-temperature alloy spherical powder.

19. The use according to claim 17, characterized in that The powder is screened under a high-purity argon atmosphere.

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