A method for preparing a nickel-based alloy strip for photo-thermal power generation and energy storage

Abstract

The application provides a preparation method of a nickel-based alloy strip for photo-thermal power generation and energy storage, and the preparation method comprises the following steps: S1: placing a first metal and a second metal into a vacuum induction melting furnace, heating to uniformly melt the metals into a whole under air isolation, naturally cooling to room temperature after melting, and obtaining an intermediate layer; S2: hot-rolling the upper surface nickel-based alloy layer and the intermediate layer to be compounded, and hot-rolling the upper surface nickel-based alloy layer and the intermediate layer to be compounded into a composite strip under first rolling, first intermediate annealing, second rolling, second intermediate annealing, third rolling and first heat treatment. The nickel-based alloy strip prepared by the preparation method has high strength, good corrosion resistance, excellent phase change energy storage performance, good heat conductivity, and fills the gap of high-performance materials for photo-thermal power generation and energy storage in China.

Description

Technical Field

[0001] This invention belongs to the field of alloy material processing technology, and particularly relates to a method for preparing nickel-based alloy strips for solar thermal power generation and energy storage. Background Technology

[0002] Solar thermal power generation is a completely clean power generation method that does not produce secondary pollution. Furthermore, solar thermal power generation technology is suitable for large-scale applications, with low unit cost and relatively mature technology, and it has already been widely put into commercial operation abroad. Heat transfer and storage technology is one of the key technologies in solar thermal power generation. The characteristics of the heat transfer and storage medium directly affect the system's heat absorption, heat transfer, and heat storage performance. Chloride salts have attracted attention due to their numerous advantages, such as wide variety, low price, the ability to be made into mixed molten salts with different melting points as needed, high latent heat of phase change, low viscosity in the molten state, good high-temperature thermal stability, and an operating temperature up to 900℃. Therefore, chloride salts are very suitable as high-temperature heat transfer and storage materials. The biggest drawback of chloride salts is their strong corrosiveness, which is the most critical problem for their application in solar thermal power plants. Overcoming this drawback would extend the service life of key components such as pipes and containers, reduce the operating and maintenance costs of power plants, and have a very promising application prospect. Among existing commercial metal materials, nickel-based alloys have relatively good resistance to chloride corrosion. For example, 625 nickel-chromium alloy is used in solar thermal power generation projects. Since all materials are sourced from abroad, we have conducted process research and development on its welded pipe strip to fill the technological gap. Summary of the Invention

[0003] This invention provides a method for preparing nickel-based alloy strips for solar thermal power generation and energy storage: the nickel-based alloy strips prepared by this method have high strength, good corrosion resistance, excellent phase change energy storage performance, and good thermal conductivity, thus solving the problem of the lack of high-performance material preparation technology for solar thermal power generation and energy storage.

[0004] To achieve the above objectives, the present invention provides a method for preparing nickel-based alloy strip for solar thermal power generation and energy storage. The nickel-based alloy strip is formed by hot rolling and composite lamination of an intermediate layer and nickel-based alloy layers located on the upper and lower surfaces of the intermediate layer. The intermediate layer includes a first metal and a second metal. The first metal is one or more of magnesium, aluminum, and zinc, and the second metal is one or more of indium, lead, cadmium, and copper. The preparation method includes the following steps:

[0005] S1: The first metal and the second metal are placed in a vacuum induction melting furnace. Under air-isolated conditions, they are heated to melt each metal uniformly into a whole. After melting, the metal is naturally cooled to room temperature to obtain the intermediate layer.

[0006] S2: The nickel-based alloy layer on the upper surface and the intermediate layer are hot-rolled together. The upper surface nickel-based alloy layer and the intermediate layer are hot-rolled together into a composite strip under the conditions of first rolling, first intermediate annealing, second rolling, second intermediate annealing, third rolling and first heat treatment.

[0007] S3: The lower surface nickel-based alloy layer is hot-rolled and bonded to the composite strip in step S2. The lower surface nickel-based alloy layer and the composite strip are hot-rolled and bonded to form a nickel-based alloy strip under the following conditions: fourth rolling, third intermediate annealing, fifth rolling, fourth intermediate annealing, sixth rolling, and second heat treatment.

[0008] As a further description of the above technical solution:

[0009] The temperatures of each zone in the first heat treatment and the second heat treatment are as follows: Zone 1: 1040℃-1060℃, Zone 2: 1070℃-1090℃, Zone 3: 1110℃-1130℃, Zone 4: 1110℃-1140℃, Zone 5: 1110℃-1130℃, and Zone 6: 1100℃-1120℃.

[0010] As a further description of the above technical solution:

[0011] The pressing speed for both the first and fourth rolling processes is 2–10 m / min.

[0012] As a further description of the above technical solution:

[0013] The pressing speed for both the second and fifth rolling processes is 3–8 m / min.

[0014] As a further description of the above technical solution:

[0015] The pressing speed for both the third and sixth rolling processes is 2–3 m / min.

[0016] As a further description of the above technical solution:

[0017] The first and third intermediate annealings are both carried out in an annealing furnace at a temperature of 950℃ to 1000℃ and a holding time of 8 to 12 hours.

[0018] As a further description of the above technical solution:

[0019] The second and fourth intermediate annealings were both carried out in an annealing furnace at a temperature of 1050℃ to 1100℃ and a holding time of 4 to 6 hours.

[0020] As a further description of the above technical solution:

[0021] Rare earth elements are added to the upper and lower nickel-based alloy layers during smelting. During the smelting process, the rare earth elements react with oxygen and sulfur to generate rare earth oxysulfides. After quenching, the rare earth oxides and sulfides are removed from the steel. After multiple cold pressing and intermediate heat treatments, a strip that meets the requirements is obtained.

[0022] As a further description of the above technical solution:

[0023] In step S1, one or more of magnesium, aluminum, and zinc are smelted with one or more of indium, lead, and cadmium, and then cooled to room temperature to obtain an intermediate. The intermediate is then melted again, and copper powder is added to the molten intermediate and stirred evenly until it cools and solidifies.

[0024] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0025] 1. The nickel-based alloy strip prepared by this invention is made by hot rolling and composite stacking of an intermediate layer and nickel-based alloy layers disposed on both sides of the intermediate layer, which can reduce the amount of nickel used. The product prepared by this invention has high bonding strength and strong composite, unlike the electroplating or chemical nickel plating process which emits a large amount of acid, alkali and other chemical substances that pollute the environment. Moreover, the intermediate layer is formed by melting one or more of magnesium, aluminum and zinc and one or more of indium, lead and cadmium, which has excellent phase change energy storage performance.

[0026] 2. In this invention, rare earth elements are added to the nickel-based alloy layer during smelting. During the smelting process, rare earth elements react with oxygen and sulfur to generate rare earth oxysulfides. After quenching, rare earth oxides and sulfides are removed from the steel, which can effectively increase the purity of the billet and refine the as-cast grains of the billet, laying the foundation for avoiding coarse grains in subsequent processing. The resulting strip grain size is generally grade 7. Cold rolling is used to fully break down the material microstructure, and continuous heat treatment is used to anneal the material to ensure that the material performance meets the requirements. The material microstructure is precisely controlled, resulting in the following material properties: tensile strength 786MPa, yield strength 440MPa, elongation 40%, and grain size grade 7.

[0027] 3. In this invention, by adding copper in the intermediate layer, copper acts as a nucleating agent for the phase change energy storage alloy, promoting the solidification of the alloy and keeping the solidification and melting phase change heat hysteresis within a small range, which is beneficial for the precise control of the phase change temperature. Detailed Implementation

[0028] The preferred embodiments of the present invention will now be described in detail.

[0029] This invention provides a method for preparing nickel-based alloy strip for solar thermal power generation and energy storage. The nickel-based alloy strip is formed by hot rolling and composite bonding of an intermediate layer and nickel-based alloy layers located on the upper and lower surfaces of the intermediate layer. The intermediate layer includes a first metal and a second metal. The first metal is one or more of magnesium, aluminum, and zinc, and the second metal is one or more of indium, lead, cadmium, and copper. The preparation method includes the following steps:

[0030] S1: The first metal and the second metal are placed in a vacuum induction melting furnace. Under air-isolated conditions, they are heated to melt each metal uniformly into a whole. After melting, the metal is naturally cooled to room temperature to obtain the intermediate layer.

[0031] S2: The nickel-based alloy layer on the upper surface and the intermediate layer are hot-rolled together. The upper surface nickel-based alloy layer and the intermediate layer are hot-rolled together into a composite strip under the conditions of first rolling, first intermediate annealing, second rolling, second intermediate annealing, third rolling and first heat treatment.

[0032] S3: The lower surface nickel-based alloy layer is hot-rolled and bonded to the composite strip in step S2. The lower surface nickel-based alloy layer and the composite strip are hot-rolled and bonded to form a nickel-based alloy strip under the following conditions: fourth rolling, third intermediate annealing, fifth rolling, fourth intermediate annealing, sixth rolling, and second heat treatment.

[0033] The temperatures of each zone in the first heat treatment and the second heat treatment are as follows: Zone 1: 1040℃-1060℃, Zone 2: 1070℃-1090℃, Zone 3: 1110℃-1130℃, Zone 4: 1110℃-1140℃, Zone 5: 1110℃-1130℃, and Zone 6: 1100℃-1120℃.

[0034] The pressing speed for both the first and fourth rolling processes is 2–10 m / min.

[0035] The pressing speed for both the second and fifth rolling processes is 3–8 m / min.

[0036] The pressing speed for both the third and sixth rolling processes is 2–3 m / min.

[0037] The first and third intermediate annealings are both carried out in an annealing furnace at a temperature of 950℃ to 1000℃ and a holding time of 8 to 12 hours.

[0038] The second and fourth intermediate annealings were both carried out in an annealing furnace at a temperature of 1050℃ to 1100℃ and a holding time of 4 to 6 hours.

[0039] Rare earth elements are added to the upper and lower nickel-based alloy layers during smelting. During the smelting process, the rare earth elements react with oxygen and sulfur to generate rare earth oxysulfides. After quenching, the rare earth oxides and sulfides are removed from the steel. After multiple cold pressing and intermediate heat treatments, a strip that meets the requirements is obtained.

[0040] In step S1, one or more of magnesium, aluminum, and zinc are smelted with one or more of indium, lead, and cadmium, and then cooled to room temperature to obtain an intermediate. The intermediate is then melted again, and copper powder is added to the molten intermediate and stirred evenly until it cools and solidifies.

[0041] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are that the nickel-based alloy strip prepared by the present invention is made by hot rolling composite of an intermediate layer and nickel-based alloy layers disposed on both sides of the intermediate layer, which can reduce the amount of nickel used. The product prepared by the present invention has high bonding strength and strong composite, unlike the electroplating or chemical nickel plating manufacturing process which emits a large amount of acid, alkali and other chemical substances that pollute the environment. Moreover, the intermediate layer is formed by melting one or more of magnesium, aluminum and zinc and one or more of indium, lead and cadmium, which has excellent phase change energy storage performance. This invention incorporates rare earth elements into the nickel-based alloy layer during smelting. During smelting, these rare earth elements react with oxygen and sulfur to form rare earth oxysulfides. After quenching, the rare earth oxides and sulfides are removed from the steel, effectively increasing the purity of the billet and refining the as-cast grains. This lays the foundation for avoiding coarse grains in subsequent processing, resulting in strips with a grain size generally around grade 7. Cold rolling is used to fully break down the material's microstructure, and continuous heat treatment is employed to anneal the material, ensuring that its performance meets requirements. Precise control of the material's microstructure results in the following properties: tensile strength 786 MPa, yield strength 440 MPa, elongation 40%, and grain size grade 7.

[0042] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto: one or more of magnesium, aluminum, and zinc, wherein the second metal is indium, lead, cadmium, or copper.

[0043] Example 1

[0044] Example 1 provides a method for preparing nickel-based alloy strips for solar thermal power generation and energy storage, which includes the following steps:

[0045] S1: Magnesium, aluminum, zinc, indium, lead, and cadmium are placed in a vacuum induction melting furnace. Under air-isolated conditions, the metals are heated to melt uniformly into a whole. After melting, the mixture is naturally cooled to room temperature to obtain the intermediate layer. The intermediate is then melted again, and copper powder is added to the melted intermediate. The mixture is stirred until it cools and solidifies.

[0046] S2: The nickel-based alloy layer on the upper surface and the intermediate layer are hot-rolled together. The upper surface nickel-based alloy layer and the intermediate layer are hot-rolled together into a composite strip under the conditions of first rolling, first intermediate annealing, second rolling, second intermediate annealing, third rolling and first heat treatment.

[0047] S3: The lower surface nickel-based alloy layer is hot-rolled and bonded to the composite strip in step S2. The lower surface nickel-based alloy layer and the composite strip are hot-rolled and bonded to form a nickel-based alloy strip under the following conditions: fourth rolling, third intermediate annealing, fifth rolling, fourth intermediate annealing, sixth rolling, and second heat treatment.

[0048] The temperatures of each zone in the first heat treatment and the second heat treatment are as follows: Zone 1 1040℃, Zone 2 1070℃, Zone 3 1110℃, Zone 4 1110℃, Zone 5 1110℃, and Zone 6 1100℃.

[0049] The pressing speed for both the first and fourth rolling processes is 2 m / min.

[0050] The pressing speed for both the second and fifth rolling processes is 3 m / min.

[0051] The pressing speed for both the third and sixth rolling processes is 2 m / min.

[0052] The first and third intermediate annealings were both carried out in an annealing furnace at a temperature of 950°C for 8 hours.

[0053] The second and fourth intermediate annealings were both carried out in an annealing furnace at a temperature of 1050°C for 4 hours.

[0054] Example 2

[0055] Example 2 provides a method for preparing nickel-based alloy strips for solar thermal power generation and energy storage, which is basically the same as that in Example 1, except that the temperatures in each heat treatment zone are as follows:

[0056] The temperatures of each zone in the first heat treatment and the second heat treatment are as follows: Zone 1 1050℃, Zone 2 1080℃, Zone 3 1120℃, Zone 4 1120℃, Zone 5 1120℃, and Zone 6 1110℃.

[0057] The pressing speed for both the first and fourth rolling processes is 2 m / min.

[0058] The pressing speed for both the second and fifth rolling processes is 2 m / min.

[0059] The pressing speed for both the third and sixth rolling processes is 2 m / min.

[0060] The first and third intermediate annealings were both carried out in an annealing furnace at a temperature of 1000℃ for 8 hours.

[0061] The second and fourth intermediate annealings were both carried out in an annealing furnace at a temperature of 1100°C for 4 hours.

[0062] Comparative Example 1

[0063] Comparative Example 1 provides a method for preparing nickel-based alloy strip for solar thermal power generation and energy storage, which is basically the same as Example 1, except that there is no first rolling or first intermediate annealing.

[0064] Comparative Example 2

[0065] Comparative Example 2 provides a method for preparing nickel-based alloy strip for solar thermal power generation and energy storage, which is basically the same as that of Example 1, except that there is no second rolling or second intermediate annealing.

[0066] Comparative Example 3

[0067] Comparative Example 3 provides a method for preparing nickel-based alloy strips for solar thermal power generation and energy storage, which is basically the same as that of Example 1, except that no heat treatment is performed.

[0068] The product performance of the above embodiments and comparative examples was tested; the test results are shown in Table 1; the test methods were carried out in accordance with the relevant national standards.

[0069] Table 1

[0070] project Tensile strength (MPa) Yield strength (MPa) Elongation (%) Average grain diameter dn x 100 (mm) Example 1 750 420 36 6.5 Example 2 786 440 40 7 Comparative Example 1 726 400 30 6.0 Comparative Example 2 727 390 29 6.2 Comparative Example 3 730 406 25 4

[0071] As can be seen from the table above, the nickel-based alloys prepared by the method disclosed in the embodiments of the present invention have good mechanical properties.

[0072] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing nickel-based alloy strip for solar thermal power generation and energy storage, characterized in that, The nickel-based alloy strip is hot-rolled and laminated from an intermediate layer and nickel-based alloy layers located on the upper and lower surfaces of the intermediate layer. The intermediate layer includes a first metal and a second metal. The first metal is one or more of magnesium, aluminum, and zinc, and the second metal is one or more of indium, lead, cadmium, and copper. The preparation method includes the following steps: S1: The first metal and the second metal are placed in a vacuum induction melting furnace. Under air-isolated conditions, they are heated to melt each metal uniformly into a whole. After melting, the metal is naturally cooled to room temperature to obtain the intermediate layer. S2: The nickel-based alloy layer on the upper surface and the intermediate layer are hot-rolled together. The upper surface nickel-based alloy layer and the intermediate layer are hot-rolled together into a composite strip under the conditions of first rolling, first intermediate annealing, second rolling, second intermediate annealing, third rolling and first heat treatment. S3: The lower surface nickel-based alloy layer is hot-rolled and bonded to the composite strip in step S2. The lower surface nickel-based alloy layer and the composite strip are hot-rolled and bonded to form a nickel-based alloy strip under the conditions of fourth rolling, third intermediate annealing, fifth rolling, fourth intermediate annealing, sixth rolling, and second heat treatment. Rare earth elements are added to the upper and lower nickel-based alloy layers during smelting. During smelting, the rare earth elements react with oxygen and sulfur to generate rare earth oxides and sulfides. After quenching, the rare earth oxides and sulfides are removed from the steel. After multiple cold pressings and intermediate heat treatments, a strip meeting the requirements is obtained. In step S1, one or more of magnesium, aluminum, and zinc are smelted with one or more of indium, lead, and cadmium, and then cooled to room temperature to obtain an intermediate. The intermediate is then remelted, and copper powder is added to the molten intermediate and stirred until it cools and solidifies. The first heat treatment and the... The temperatures of each zone in the second heat treatment are as follows: Zone 1 1040℃-1060℃, Zone 2 1070℃-1090℃, Zone 3 1110℃-1130℃, Zone 4 1110℃-1140℃, Zone 5 1110℃-1130℃, and Zone 6 1100℃-1120℃. The pressing speed of the first and fourth rolling processes is 2-10 m / min, the pressing speed of the second and fifth rolling processes is 3-8 m / min, and the pressing speed of the third and sixth rolling processes is 2-3 m / min.

2. The method for preparing nickel-based alloy strip for solar thermal power generation and energy storage according to claim 1, characterized in that, The first and third intermediate annealings are both carried out in an annealing furnace at a temperature of 950℃ to 1000℃ and a holding time of 8 to 12 hours.

3. The method for preparing nickel-based alloy strip for solar thermal power generation and energy storage according to claim 1, characterized in that, The second and fourth intermediate annealings were both carried out in an annealing furnace at a temperature of 1050℃ to 1100℃ and a holding time of 4 to 6 hours.