阅读说明：本技术 一种镍钴基变形高温合金及其制备方法 (Nickel-cobalt-based wrought high-temperature alloy and preparation method thereof ) 是由 张瑞 王新广 崔传勇 周亦胄 孙晓峰 于 2020-05-09 设计创作，主要内容包括：本发明是关于一种镍钴基变形高温合金及其制备方法,涉及高温合金技术领域。主要采用的技术方案为：所述镍钴基变形高温合金中具有特殊晶界,特殊晶界的体积分数≥25％。所述镍钴基变形高温合金的制备方法,包括如下步骤：对热轧处理后的镍钴基高温合金进行固溶处理；将固溶处理后的镍钴基高温合金进行总变形量为50-80％的冷轧；在真空或氢还原环境中,将变形处理后的镍钴基高温合金在0.8-0.9Tm的温度下退火5-30min；对退火处理后的镍钴基高温合金进行时效处理,得到镍钴基变形高温合金。本发明主要用于将特殊晶界引入镍钴基变形高温合金中,并提高特殊晶界的体积分数,在不增加合金化程度的前提下,改善合金的强度,为镍钴基变形高温合金作为高温结构件提供强度保障。(The invention relates to a nickel-cobalt-based wrought high-temperature alloy and a preparation method thereof, relating to the technical field of high-temperature alloys. The main technical scheme adopted is as follows: the nickel-cobalt-based wrought superalloy has a special crystal boundary, and the volume fraction of the special crystal boundary is more than or equal to 25%. The preparation method of the nickel-cobalt-based wrought superalloy comprises the following steps: carrying out solution treatment on the nickel-cobalt-based high-temperature alloy subjected to hot rolling treatment; cold rolling the nickel-cobalt-based high-temperature alloy subjected to solution treatment with the total deformation of 50-80%; annealing the nickel-cobalt-based high-temperature alloy subjected to deformation treatment for 5-30min at the temperature of 0.8-0.9Tm in a vacuum or hydrogen reduction environment; and carrying out aging treatment on the nickel-cobalt-based high-temperature alloy after annealing treatment to obtain the nickel-cobalt-based wrought high-temperature alloy. The method is mainly used for introducing the special crystal boundary into the nickel-cobalt-based wrought high-temperature alloy, improving the volume fraction of the special crystal boundary, improving the strength of the alloy on the premise of not increasing the alloying degree, and providing strength guarantee for the nickel-cobalt-based wrought high-temperature alloy as a high-temperature structural member.)

1. The nickel-cobalt-based wrought superalloy is characterized in that the nickel-cobalt-based wrought superalloy has special crystal boundaries, and the volume fraction of the special crystal boundaries is more than or equal to 25%; the special grain boundary refers to a lattice grain boundary of Σ 3, Σ 9, and Σ 27 type overlapping positions.

2. The nickel-cobalt-based wrought superalloy according to claim 1, wherein the nickel-cobalt-based wrought superalloy comprises, in weight percent: 10-35% of Co, 0-5% of Ta, 10-25% of Cr, 3-7% of Ti, 0.2-5% of Al, 0.1-5% of W, 0.1-5% of Mo, 0.1-5% of Nb, 0.1-1% of Mn, 0.1-1% of V, 0.001-0.2% of C, 0.01-0.1% of ZrC, 0.01-0.1% of B and the balance of Ni and inevitable impurities.

3. The nickel-cobalt-based wrought superalloy according to claim 1, wherein γ' phases in grains of the nickel-cobalt-based wrought superalloy are multi-dimensionally distributed; wherein the dimension includes micro-scale and nano-scale.

4. The nickel-cobalt-based wrought superalloy according to any of claims 1-3,

the yield strength of the nickel-cobalt-based wrought high-temperature alloy at 750 ℃ is 850-1200 MPa; and/or

The tensile strength of the nickel-cobalt-based wrought high-temperature alloy at 750 ℃ is 980-1500 MPa; and/or

The service life of the nickel-cobalt-based wrought superalloy is 80-300h under the creep test conditions that the temperature is 750 ℃ and the tensile force is 530 MPa.

5. A method of making a nickel cobalt wrought superalloy as in any of claims 1 to 4, comprising the steps of:

solution treatment: carrying out solution treatment on the nickel-cobalt-based high-temperature alloy subjected to hot rolling treatment; preferably, the average grain size of the nickel-cobalt-based high-temperature alloy after hot rolling treatment is not more than 100 μm;

deformation treatment: cold rolling the nickel-cobalt-based high-temperature alloy subjected to solution treatment with the total deformation of 50-80%;

annealing treatment: annealing the nickel-cobalt-based high-temperature alloy subjected to deformation treatment for 5-30min at the temperature of 0.8-0.9Tm in a vacuum or hydrogen reduction environment; wherein Tm is the melting point temperature of the nickel-cobalt-based high-temperature alloy;

aging treatment: and carrying out aging treatment on the nickel-cobalt-based high-temperature alloy after annealing treatment to obtain the nickel-cobalt-based wrought high-temperature alloy.

6. The method of claim 5, wherein the solution treatment comprises the steps of: carrying out solution treatment on the nickel-cobalt-based high-temperature alloy subjected to hot rolling treatment at the temperature of 0.85-0.95Tm for 2-4h, and then cooling to room temperature; preferably, after cooling to room temperature, the nickel-cobalt-based high-temperature alloy after solution treatment is also subjected to acid cleaning and drying treatment;

and/or

In the step of deforming: the pressing rate of each pass is 10-15%; preferably, the emulsion is adopted for lubrication during cold rolling;

and/or

In the step of annealing treatment: before annealing, alkali washing and drying treatment are carried out on the nickel-cobalt-based high-temperature alloy after deformation treatment; and/or gas quenching the annealed nickel-cobalt-based high-temperature alloy to room temperature.

7. The method of claim 5, wherein the aging step comprises:

the first step of aging treatment: in a vacuum or hydrogen reduction environment, keeping the temperature of the annealed nickel-cobalt-based high-temperature alloy at a first temperature for 15-30h, and then performing gas quenching to room temperature; wherein the first temperature is lower than the precipitation phase solid solution temperature by 450-550 ℃;

the second step of aging treatment: in a vacuum or hydrogen reduction environment, keeping the temperature of the nickel-cobalt-based high-temperature alloy subjected to the aging treatment in the first step at a second temperature for 15-25h, and then performing gas quenching to room temperature; wherein the second temperature is lower than the solid solution temperature of the precipitated phase by 350-450 ℃.

8. The method of making a nickel-cobalt-based wrought superalloy according to any of claims 5-7, further comprising, prior to the step of solution treating:

preparing a nickel-cobalt-based high-temperature alloy ingot: after the raw materials are subjected to smelting treatment and refining treatment, casting the raw materials into ingots to obtain nickel-cobalt-based high-temperature alloy ingots;

preparing an electroslag refining ingot: carrying out electroslag remelting refining treatment on the nickel-cobalt-based high-temperature alloy cast ingot to obtain an electroslag refining cast ingot;

hot rolling treatment: and after homogenizing the electroslag refining cast ingot, cogging the cast ingot on a hot rolling mill, and carrying out hot rolling treatment to obtain the nickel-cobalt-based high-temperature alloy after the hot rolling treatment.

9. The method of claim 8, wherein the raw materials comprise, in weight percent: 10-35% of Co, 0-5% of Ta, 10-25% of Cr, 3-7% of Ti, 0.2-5% of Al, 0.1-5% of W, 0.1-5% of Mo, 0.1-5% of Nb, 0.1-1% of Mn, 0.1-1% of V, 0.001-0.2% of C, 0.01-0.1% of Zr, 0.01-0.1% of B and the balance of Ni; and/or

In the step of preparing the nickel-cobalt-based high-temperature alloy ingot, the smelting treatment temperature is 1450-1600 ℃, the refining treatment temperature is 1500-1800 ℃, the refining time is 5-8min, and the vacuum degree during the smelting treatment and the refining treatment is 0.5 × 10^-2Pa-0.6×10^-2Pa。

10. The method of producing a nickel-cobalt-based wrought superalloy according to claim 8, wherein in the hot rolling step:

heating the electroslag refining ingot to 0.85-0.9Tm, and preserving heat for 5-10h for homogenization treatment; and/or

And (3) during hot rolling treatment: the initial rolling temperature is 0.85-0.9Tm, the reduction rate is 80-100%, the final rolling temperature is more than or equal to 0.7Tm, and the steel is cooled to room temperature when the steel is rolled to the thickness of 3-5 mm.

Technical Field

The invention relates to the technical field of high-temperature alloys, in particular to a nickel-cobalt-based wrought high-temperature alloy and a preparation method thereof.

Background

The high-temperature alloy is a key material in the fields of aviation power, gas turbines, supercritical power stations, nuclear energy, petrochemicals and the like, and the performance of the high-temperature alloy is an important mark for determining the national technological development level. The deformed high-temperature alloy plate or foil can be used as a thermal protection component of an outer panel of an aircraft, a flame tube or a combustion chamber of an engine; the service environment of the application fields is harsh, and the deformed high-temperature alloy is required to have the characteristics of light weight, heat corrosion resistance, long high-temperature durable service life and the like so as to meet the performance indexes of light weight and high Mach of the aircraft and have excellent maneuverability.

With the development of the technology, in order to meet increasingly demanding performance requirements of aerospace power systems or other high-end equipment, researchers improve the temperature bearing capacity or high-temperature strength level of materials by continuously improving the alloying degree or adding rare and precious metals. However, this method results in increased costs for raw metal materials and recycling, and increased difficulty in alloy smelting and hot working. Moreover, the traditional mode of improving the performance of the high-temperature alloy by improving the alloying degree also meets the bottleneck, and the updating speed of the high-temperature alloy is slowed down. Therefore, a special method for strengthening the nickel-cobalt-based wrought superalloy is urgently needed, so that the performance of the alloy meets the industrial development requirement.

In the nickel-cobalt-based wrought superalloy, an element such as W, Mo is added to improve the solid solution strengthening effect, Al, Ti, and Nb are added to improve the precipitation strengthening effect, and Co and Ta are added to reduce the stacking fault energy of the alloy. The low-stacking fault energy is an important material attribute of the nickel-cobalt-based wrought superalloy, and the attribute enables the alloy to generate a large amount of micro-twin crystals or stacking faults in the service process, and the alloy has excellent coordination and strengthening effects due to the interaction between the stacking faults (micro-twin crystals) and the action of the stacking faults (micro-twin crystals) and precipitated phases. How to further exert the strengthening effect of the nickel-cobalt-based alloy and improve the service temperature of the alloy is always a pursuit target of scientific workers.

The lattice grain boundary with low coincident position is a special large-angle grain boundary with lower free energy, higher stability and lower grain boundary mobility, and not only can effectively block the movement of dislocation and reduce the grain size of alloy, but also can play a role in strengthening the alloy. However, there is no current technique related to strengthening alloys by introducing special grain boundaries into nickel-cobalt-based wrought superalloy.

Disclosure of Invention

In view of the above, the present invention provides a nickel-cobalt-based wrought superalloy and a method for preparing the same, and the main object of the present invention is to provide or prepare a nickel-cobalt-based wrought superalloy with a special grain boundary to strengthen the alloy.

In order to achieve the purpose, the invention mainly provides the following technical scheme:

in one aspect, embodiments of the present invention provide a nickel-cobalt-based wrought superalloy, wherein the nickel-cobalt-based wrought superalloy has special grain boundaries therein; the special grain boundaries are Σ 3, Σ 9, and Σ 27 type overlapping position lattice grain boundaries (here, the Σ 3, Σ 9, and Σ 27 type overlapping position lattice grain boundaries are low overlapping position lattice grain boundaries).

Preferably, the volume fraction of the special crystal boundary in the nickel-cobalt-based wrought superalloy is more than or equal to 25%.

Preferably, the nickel-cobalt-based wrought superalloy comprises the following components in weight percent: 10-35% of Co, 0-5% of Ta, 10-25% of Cr, 3-7% of Ti, 0.2-5% of Al, 0.1-5% of W, 0.1-5% of Mo, 0.1-5% of Nb, 0.1-1% of Mn, 0.1-1% of V, 0.001-0.2% of C, 0.01-0.1% of Zr, 0.01-0.1% of B, and the balance of Ni and inevitable impurities.

Preferably, the gamma' phase in the crystal grains of the nickel-cobalt-based wrought superalloy is distributed in a multi-scale mode; wherein the dimension includes micro-scale and nano-scale.

Preferably, the yield strength of the nickel-cobalt-based wrought high-temperature alloy at 750 ℃ is 850-1200 MPa; and/or the tensile strength of the nickel-cobalt-based wrought high-temperature alloy at 750 ℃ is 980-1500 MPa; and/or the service life of the nickel-cobalt-based wrought superalloy is 80-300h under the creep test conditions that the temperature is 750 ℃ and the tensile force is 530 MPa.

In another aspect, an embodiment of the present invention provides a method for preparing a nickel-cobalt-based wrought superalloy, for preparing any of the nickel-cobalt-based wrought superalloys described above; the method comprises the following steps:

solution treatment: performing solution treatment on the nickel-cobalt-based high-temperature alloy after the hot rolling treatment (here, the nickel-cobalt-based high-temperature alloy after the hot rolling treatment is a hot rolled plate);

deformation treatment: cold rolling the nickel-cobalt-based high-temperature alloy subjected to solution treatment with the total deformation of 50-80%;

annealing treatment: annealing the nickel-cobalt-based high-temperature alloy subjected to deformation treatment for 5-30min at the temperature of 0.8-0.9Tm in a vacuum or hydrogen reduction environment; wherein Tm is the melting point temperature of the nickel-cobalt-based high-temperature alloy;

aging treatment: and carrying out aging treatment on the nickel-cobalt-based high-temperature alloy after annealing treatment to obtain the nickel-cobalt-based wrought high-temperature alloy.

Preferably, the average grain size of the nickel-cobalt-based high-temperature alloy after the hot rolling treatment is not more than 100 μm.

Preferably, the solution treatment step specifically comprises: carrying out solution treatment on the nickel-cobalt-based high-temperature alloy subjected to hot rolling treatment at the temperature of 0.85-0.95Tm for 2-4h, and then cooling to room temperature; preferably, after cooling to room temperature, the nickel-cobalt-based high-temperature alloy after solution treatment is also subjected to acid cleaning and drying treatment.

Preferably, in the deforming process: the pressing rate of each pass is 10-15%; preferably, the emulsion is used for lubrication during cold rolling.

Preferably, in the step of annealing treatment: before annealing, alkali washing and drying treatment are carried out on the nickel-cobalt-based high-temperature alloy after deformation treatment; and/or gas quenching the annealed nickel-cobalt-based high-temperature alloy to room temperature.

Preferably, the aging treatment step includes:

the first step of aging treatment: in a vacuum or hydrogen reduction environment, keeping the temperature of the annealed nickel-cobalt-based high-temperature alloy at a first temperature for 15-30h, and then performing gas quenching to room temperature; wherein the first temperature is lower than the precipitation phase solid solution temperature by 450-550 ℃ (wherein the precipitation phase solid solution temperature refers to the complete precipitation phase re-dissolution temperature);

the second step of aging treatment: in a vacuum or hydrogen reduction environment, keeping the temperature of the nickel-cobalt-based high-temperature alloy subjected to the aging treatment in the first step at a second temperature for 15-25h, and then performing gas quenching to room temperature; wherein the second temperature is lower than the solid solution temperature of the precipitated phase by 350-450 ℃.

Preferably, before the solution treatment step, the method further comprises:

preparing a nickel-cobalt-based high-temperature alloy ingot: after the raw materials are subjected to smelting treatment and refining treatment, casting the raw materials into ingots to obtain nickel-cobalt-based high-temperature alloy ingots;

preparing an electroslag refining ingot: carrying out electroslag remelting refining treatment on the nickel-cobalt-based high-temperature alloy cast ingot to obtain an electroslag refining cast ingot;

hot rolling treatment: and after homogenizing the electroslag refining cast ingot, cogging the cast ingot on a hot rolling mill, and carrying out hot rolling treatment to obtain the nickel-cobalt-based high-temperature alloy after the hot rolling treatment.

Preferably, the raw materials comprise the following components in percentage by weight: 10-35% of Co, 0-5% of Ta, 10-25% of Cr, 3-7% of Ti, 0.2-5% of Al, 0.1-5% of W, 0.1-5% of Mo, 0.1-5% of Nb, 0.1-1% of Mn, 0.1-1% of V, 0.001-0.2% of C, 0.01-0.1% of Zr, 0.01-0.1% of B and the balance of Ni.

Preferably, in the step of preparing the nickel-cobalt-based superalloy ingot: the temperature of the smelting treatment is 1450-1600 ℃; the temperature of the refining treatment is 1500-The vacuum degree during smelting and refining is 0.5 × 10^-2Pa-0.6×10^-2Pa。

Preferably, in the hot rolling treatment step:

heating the electroslag refining ingot to 0.85-0.9Tm, and preserving heat for 5-10h for homogenization treatment; and/or

And (3) during hot rolling treatment: the initial rolling temperature is 0.85-0.9Tm, the reduction rate is 80-100%, the final rolling temperature is more than or equal to 0.7Tm, and the steel is cooled to room temperature when the steel is rolled to the thickness of 3-5 mm.

Compared with the prior art, the nickel-cobalt-based wrought superalloy and the preparation method thereof have at least the following beneficial effects:

in one aspect, embodiments of the present invention provide a nickel-cobalt-based wrought superalloy, which has special grain boundaries (i.e., lattice grain boundaries of the Σ 3, Σ 9, and Σ 27 types of overlapping positions) in the nickel-cobalt-based wrought superalloy, and a volume fraction of the special grain boundaries is not less than 25%; in this case, the nickel-cobalt-based wrought superalloy has excellent hot corrosion resistance due to the low free energy of the special grain boundaries. Meanwhile, the grain boundary segregation of trace elements such as C, Zr, B and the like in the alloy is utilized, the stable distribution of special grain boundaries in a high-temperature environment is realized, the aim of strengthening the alloy is fulfilled, the service temperature of the nickel-cobalt-based wrought high-temperature alloy is finally improved, and the strength guarantee is provided for the nickel-cobalt-based wrought high-temperature alloy as a high-temperature structural member.

On the other hand, the embodiment of the invention provides a preparation method of the nickel-cobalt-based wrought high-temperature alloy, which is characterized in that the nickel-cobalt-based wrought high-temperature alloy (hot rolled plate) after hot rolling treatment is subjected to solution treatment, deformation treatment, annealing treatment and aging treatment, a special crystal boundary is introduced into the nickel-cobalt-based wrought high-temperature alloy by controlling the deformation, the annealing temperature and the annealing time, the volume fraction of the lattice crystal boundary at the low coincident position in the alloy is effectively regulated and controlled, and the purpose of improving the high-temperature strength of the alloy is realized.

Further, the solution treatment step in the preparation method of the nickel-cobalt-based wrought superalloy provided by the embodiment of the invention aims to completely recrystallize a hot rolled plate, so that a large amount of gamma' phase in a matrix is dissolved back, residual internal stress generated in the alloy due to hot rolling is eliminated, a uniform structure is provided for the next cold rolling deformation process, and the deformation resistance of the alloy in the cold rolling deformation process is reduced. The selection of the solid solution temperature and the heat preservation time is based on eliminating residual stress, redissolving gamma 'phase and controlling the grain size, so the solid solution treatment is carried out for 2-4h at the temperature of 0.85-0.95Tm, on one hand, sufficient time is provided to ensure that the recrystallization is sufficient, the residual internal stress is completely recovered, and the gamma' phase is largely redissolved, on the other hand, the growth of alloy grains is inhibited, and the abnormal growth of the grains is prevented.

Further, the purpose of the deformation treatment step in the preparation method of the nickel-cobalt-based wrought superalloy provided by the embodiment of the invention is to introduce deformation distortion energy and provide power for inducing recrystallization by the subsequent annealing treatment. The step is to ensure that uniform and sufficient deformation distortion energy is introduced, and simultaneously inhibit the alloy temperature rise caused by deformation, so that cold rolling with the total deformation of 50-80% is selected, the reduction rate of each pass is 10-15%, the reduction rate of each pass can be controlled to inhibit deformation and temperature rise, and the deformation is uniform, and the total deformation amount is controlled to ensure that the sufficient deformation distortion energy is introduced.

Further, the annealing step in the method for preparing the nickel-cobalt-based wrought superalloy provided by the embodiment of the present invention mainly aims to induce recrystallization, and the alloy with lower layer fault energy induces generation of a large amount of lattice grain boundaries with low coincident positions in the static recrystallization process. The process prevents abnormal growth of crystal grains on the premise of ensuring full recrystallization, and simultaneously slows down the migration rate of crystal boundaries as much as possible to achieve the purpose of inducing more lattice crystal boundaries with low coincident positions. Therefore, annealing is carried out for 5-30min in a vacuum or hydrogen reduction environment at the temperature of 0.8-0.9Tm, so that the grain boundary migration rate in the recrystallization process is controlled, the recrystallization is ensured to be fully carried out, and abnormal growth of grains is inhibited.

Further, the purpose of the aging treatment in the preparation method of the nickel-cobalt-based wrought superalloy provided by the embodiment of the present invention is to fully precipitate the γ 'phase in the matrix, so that the alloy has an excellent precipitation strengthening effect, and the γ' phase is distributed in a multi-scale manner in the process, so that the dual aging treatment is performed: keeping the temperature for 15-30h in a vacuum or hydrogen reduction environment at the temperature of 450-550 ℃ below the solid solution temperature of the precipitated phase, and then keeping the temperature for 10-25h in a vacuum or hydrogen reduction environment at the temperature of 350-450 ℃ below the solid solution temperature of the precipitated phase. The first step of aging treatment ensures that the gamma 'phase is fully precipitated, and the second step of aging treatment enables partial gamma' phase to grow up.

In summary, the preparation method of the nickel-cobalt-based wrought high-temperature alloy provided by the embodiment of the invention introduces a large amount of special grain boundaries into the alloy through deformation and heat treatment means with few steps, easy operation, no pollution and low cost on the basis of not changing the alloying degree of the material, thereby achieving the purposes of improving the heat strength and the heat corrosion resistance of the alloy.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical solutions of the present invention more clearly understood and to implement them in accordance with the contents of the description, the following detailed description is given with reference to the preferred embodiments of the present invention and the accompanying drawings.

Drawings

FIG. 1 is a microstructure diagram of a nickel-cobalt-based wrought superalloy prepared in comparative example 1 of the present invention;

FIG. 2 is a microstructure of a nickel-cobalt-based wrought superalloy prepared in example 1 of the present invention;

FIG. 3 is a microstructure of a nickel-cobalt-based wrought superalloy prepared in example 2 of the present invention;

FIG. 4 is a microstructure of a nickel-cobalt-based wrought superalloy prepared in example 3 of the present invention;

FIG. 5 is a microstructure of a nickel-cobalt-based wrought superalloy prepared in example 4 of the present invention;

fig. 6 is a microstructure diagram of a nickel-cobalt-based wrought superalloy prepared in example 5 of the present invention.

Detailed Description

To further explain the technical means and effects of the present invention adopted to achieve the predetermined object, the following detailed description of the embodiments, structures, features and effects according to the present invention will be made with reference to the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "an embodiment" refers to not necessarily the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

The embodiment of the invention mainly provides a nickel-cobalt-based wrought high-temperature alloy and a preparation method thereof, and particularly can effectively improve the proportion of special grain boundaries in the alloy by mainly regulating and controlling the methods of deformation and heat treatment, the alloy has excellent hot corrosion resistance due to the fact that the special grain boundaries have lower free energy, and meanwhile, the grain boundary segregation of trace elements such as C, Zr, B and the like in the alloy is utilized to realize the stable distribution of the special grain boundaries in a high-temperature environment, so that the aim of strengthening the alloy is fulfilled, the use temperature of the nickel-cobalt-based wrought high-temperature alloy is improved, the strength guarantee is provided for the wrought high-temperature alloy serving as a high-temperature structural member, and the weight of the member is reduced.

Specifically, the preparation method of the nickel-cobalt-based wrought superalloy provided by the embodiment of the invention comprises the following steps:

solution treatment: the hot rolled plate (namely, the nickel-cobalt-based high-temperature alloy after hot rolling treatment) is subjected to solution treatment for 2 to 4 hours at the temperature of 0.85 to 0.95Tm, then is cooled to room temperature by water, and is subjected to acid cleaning and drying. Here, Tm in the present invention refers to a melting point temperature of the nickel-cobalt-based superalloy.

Deformation treatment: and (3) cold rolling the plate subjected to solution treatment with the total deformation of 50-80%, and lubricating the plate by using an emulsion, wherein the reduction rate of each pass is 10-15%.

Annealing treatment: before annealing, alkali washing and drying the cold-rolled sheet, then annealing the cold-rolled sheet for 5-30min in a vacuum or hydrogen reduction environment at the temperature of 0.8-0.9Tm, and then carrying out gas quenching to room temperature.

Aging treatment: keeping the temperature for 15-30h in a vacuum or hydrogen reduction environment at the temperature of 450-550 ℃ below the solid solution temperature of the precipitated phase, and performing gas quenching to room temperature; then continuously keeping the temperature for 10-25h in a vacuum or hydrogen reduction environment at the temperature of 350-450 ℃ below the solid solution temperature of the precipitated phase, and carrying out gas quenching to the room temperature.

The nickel-cobalt-based high-temperature alloy aimed at by the preparation method comprises the following components in percentage by weight: co 10-35%, Ta 0-5%, Cr 10-25%, Ti 3-7%, Al 0.2-5%, W0.1-5%, Mo 0.1-5%, Nb 0.1-5%, Mn 0.1-1%, V0.1-1%, C0.001-0.2%, Zr 0.01-0.1%, B0.01-0.1%, and the balance Ni., wherein the hot rolled plate (i.e. the hot rolled Ni-Co-based high temperature alloy) is prepared by placing the raw materials into a high frequency vacuum induction melting furnace according to the above ratio, heating to 1450-^-2Pa-0.6×10^-2Pa, refining at the temperature of 1500-1800 ℃ for 5-8min after the raw materials are completely melted, then introducing inert gas, and casting a crucible into an ingot. And after the cast ingot is cooled, cutting a dead head of the cast ingot and polishing the surface of the cast ingot, and obtaining an electroslag refining cast ingot by respectively performing three stages of arc striking, fluxing agent full melting, capping and feeding and the like by using the polished cast ingot as an electrode for electroslag remelting. Keeping the temperature of the electroslag refining cast ingot at 0.85-0.9Tm for 5-10h, homogenizing, cogging on a hot mill at the rolling temperature of 0.85-0.9Tm and the rolling reduction rate of 80-100%, wherein the final rolling temperature is not less than 0.7Tm, and cooling to room temperature by water when the thickness is 3-5 mm.

The embodiment of the invention provides a preparation method of a nickel-cobalt-based wrought high-temperature alloy, which effectively regulates and controls the volume fraction of a lattice grain boundary at a low coincident position in the alloy by controlling the deformation, the annealing temperature and the annealing time, and achieves the purpose of improving the high-temperature strength of the alloy. Specifically, the purpose of the solution treatment is to completely recrystallize a hot rolled plate, so that a large amount of gamma' phase in a matrix is dissolved back, the residual internal stress generated in the alloy due to hot rolling is eliminated, a uniform structure is provided for the next cold rolling deformation process, and the deformation resistance of the alloy in the cold rolling deformation process is reduced; the selection of the solid solution temperature and the heat preservation time is based on eliminating residual stress, redissolving gamma 'phase and controlling the grain size, so the solid solution treatment is carried out for 2-4h at the temperature of 0.85-0.95Tm, on one hand, sufficient time is provided to ensure that the recrystallization is sufficient, the residual internal stress is completely recovered, and the gamma' phase is largely redissolved, on the other hand, the growth of alloy grains is inhibited, and the abnormal growth of the grains is prevented. Further, the purpose of the deformation treatment is to introduce deformation distortion energy to provide a motive force for inducing recrystallization by the subsequent annealing treatment. The step is to ensure that uniform and sufficient deformation distortion energy is introduced, and simultaneously inhibit the alloy temperature rise caused by deformation, so that cold rolling with the total deformation of 50-80% is selected, the reduction rate of each pass is 10-15%, the reduction rate of each pass can be controlled to inhibit deformation and temperature rise, and the deformation is uniform, and the total deformation amount is controlled to ensure that the sufficient deformation distortion energy is introduced. Further, the purpose of the annealing treatment is mainly to induce recrystallization, and the alloy with lower stacking fault energy induces the generation of a large amount of lattice boundaries with low coincident sites during the static recrystallization. The process prevents abnormal growth of crystal grains on the premise of ensuring full recrystallization, and simultaneously slows down the migration rate of crystal boundaries as much as possible to achieve the purpose of inducing more lattice crystal boundaries with low coincident positions. Therefore, annealing is carried out for 5-30min in a vacuum or hydrogen reduction environment at the temperature of 0.8-0.9Tm, so that the grain boundary migration rate in the recrystallization process is controlled, the recrystallization is ensured to be fully carried out, and abnormal growth of grains is inhibited. Further, the purpose of aging treatment is mainly to fully precipitate a gamma 'phase in a matrix, so that the alloy has excellent precipitation strengthening effect, and the gamma' phase is distributed in a multi-scale manner in the process, so that double aging treatment is performed: keeping the temperature for 15-30h in a vacuum or hydrogen reduction environment at the temperature of 450-550 ℃ below the solid solution temperature of the precipitated phase, and then keeping the temperature for 10-25h in the vacuum or hydrogen reduction environment at the temperature of 350-450 ℃ below the solid solution temperature of the precipitated phase. The first step of aging treatment ensures that the gamma 'phase is fully precipitated, and the second step of aging treatment enables partial gamma' phase to grow up.

In summary, the embodiment of the present invention provides a method for preparing a nickel-cobalt-based wrought high-temperature alloy, which induces a lattice grain boundary with a high volume fraction and a low coincidence position by using a heat treatment means of cold rolling and annealing to achieve the purpose of optimizing the strength of the nickel-cobalt-based wrought high-temperature alloy; the whole process has fewer steps and is simple to operate; meanwhile, no chemical reagent and toxic and polluted gas are introduced, so that the method has the advantage of environmental friendliness; in addition, the process is a combination of traditional processing means, and the cost for optimizing the strength of the alloy is greatly reduced. Most importantly, the invention realizes the purpose of optimizing the alloy performance on the premise of hardly increasing the alloy cost because other alloy elements are not added. Compared with the prior art, the preparation method of the nickel-cobalt-based wrought high-temperature alloy provided by the embodiment of the invention introduces a large amount of special crystal boundaries into the alloy through deformation and heat treatment means with few steps, easy operation, no pollution and low cost on the basis of not changing the alloying degree of the material, thereby achieving the purposes of improving the heat strength and resisting heat corrosion of the alloy.

The invention is described in further detail below by way of specific embodiments:

examples 1-5 and comparative example 1 below prepare a nickel-cobalt-based wrought superalloy. And observing the microstructure of the prepared nickel-cobalt-based wrought superalloy by adopting an Axiovert 200MAT optical microscope. The strength of the nickel-cobalt-based wrought high-temperature alloy is tested by using an INSTRON 5582 uniaxial tensile testing machine. And testing the endurance life of the nickel-cobalt-based deformed high-temperature alloy by adopting an F-25 type endurance creep testing machine. And (3) testing the solid solution temperature and the melting point temperature of the precipitated phase of the nickel-cobalt-based high-temperature alloy by adopting a Q1000 differential scanning calorimeter. Observing the microstructure of the nickel-cobalt-based wrought superalloy by adopting an SEM (scanning electron microscope) loaded with an EBSD (Electron microscope) probe, and processing EBSD data by utilizing TSL-OIM (time series-optical-interface-analysis) post-processing software to obtain the volume fraction of a special crystal boundary in the nickel-cobalt-based wrought superalloy. With respect to the term "volume fraction of specific grain boundaries" it is meant: in the nickel-cobalt-based wrought superalloy, the proportion of special grain boundaries in all grain boundaries is high.