Method for manufacturing 7072 alloy high-performance air conditioner foil with low carbon, high efficiency and short process

Abstract

The invention discloses a method for manufacturing 7072 alloy high-performance air conditioner foil in a low-carbon, efficient and short-process mode, and relates to the technical field of aluminum foil machining. S2, continuous casting and rolling; s3, cold foil rolling; s4, finished product annealing; and S5, checking and packaging. Through component adjustment, iron and silicon alloy elements are controlled at the lower limit of the national standard, generation of coarse aluminum-iron-silicon phases is reduced, and low ductility caused by coarse grains after finished product annealing is avoided; in the cold foil rolling process, indexes of a working roll and rolling oil are adjusted, process parameters are optimized, the blank is directly rolled into a finished product, the direct rolling process is beneficial to improving the mechanical property of the finished product, and punching production of downstream customers is facilitated; and after triple continuous rolling is finished, subsequent cold foil rolling continuous rolling is rapidly arranged, deformation heat generated by triple continuous rolling and rolling of each pass is fully utilized, and large-machining-rate rolling of each pass is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of aluminum foil processing, and in particular to a method for manufacturing 7072 alloy high-performance air-conditioning foil with low carbon, high efficiency and short process. Background Art

[0002] 7072 alloy air-conditioning foil is widely used in the radiators of automobile air conditioners. This is because 7072 alloy contains an appropriate amount of zinc, which can reduce the corrosion potential of the alloy and can be used as a sacrificial anode material to protect adjacent pipes and extend the service life of the radiator. At the same time, 7072 alloy has good processing performance and has excellent mechanical properties after a series of processing. Air-conditioning radiators made of 7072 alloy air-conditioning foil have good corrosion resistance and a long service life, and can adapt to different usage environments and working conditions.

[0003] As people's requirements for air-conditioning performance and quality continue to increase, as well as their emphasis on environmental protection and energy conservation, the market demand for corrosion-resistant, high-performance 7072 alloy air-conditioning foil is expected to increase further; especially in some areas with high requirements for air-conditioning service life and reliability, such as high-end household air-conditioning, automotive air-conditioning and large-scale commercial air-conditioning systems, 7072 alloy air-conditioning foil will have a broader application space.

[0004] In recent years, some companies have used the casting and rolling method and the continuous casting and rolling method to produce 7072 alloy air-conditioning foil. The production process flow of 7072 alloy air-conditioning foil products using the casting and rolling method is roughly as follows: smelting → casting and rolling → homogenization annealing → 5 passes of cold rolling → intermediate annealing → 2 passes of foil rolling → finished product annealing → inspection and packaging; the production process flow of 7072 alloy air-conditioning foil products using the continuous casting and rolling method is as follows: smelting → continuous casting and rolling → homogenization annealing → 9 passes of cold foil rolling → finished product annealing; generally speaking, the production of 7072 alloy air-conditioning foil using the above two methods requires high-temperature homogenization annealing, and the casting and rolling method also requires secondary annealing; the aforementioned process scheme requires one or two intermediate annealings, which will cause a sharp increase in production costs and extended production time. At the same time, it will face the hidden danger of insufficient mechanical properties of the finished product, affecting the use of aluminum foil punching, and causing problems such as cumbersome post-processing technology and low yield. Summary of the Invention

[0005] The purpose of the present invention is to overcome the shortcomings of the existing technology and provide a low-carbon, high-efficiency, short-process method for manufacturing 7072 alloy high-performance air-conditioning foil, simplify the process flow, reduce the number of cold foil rolling production passes, and achieve low-carbon, high-efficiency, short-process production.

[0006] The technical solution adopted in the present invention is: A method for manufacturing 7072 alloy high-performance air-conditioning foil in a low-carbon, high-efficiency and short process, comprising the following steps: S1: Smelting; 60-70% by mass of electrolytic aluminum liquid, 20-30% of remelted aluminum ingots and 5-10% of recycled aluminum scrap are placed in a smelting furnace for remelting to prepare an aluminum melt. The melt temperature of the smelting furnace is 770±5°C. Iron agent, quick-dissolving silicon, titanium agent and zinc ingot are added to the smelting furnace to adjust the alloy composition to meet the requirements. The mass percentages of the components are as follows: Si: 0.05-0.10%, Fe: 0.1-0.15%, Cu: ≤0.02%, Zn: 0.8-0.9%, Ti: 0.015-0.025%, other individual impurities ≤0.03% and total ≤0.15%, and the balance is Al; After refining, slagging and standing, the aluminum melt is qualified and ready for furnace starting. The melt flows into the degassing box through the diversion flow channel for online degassing, and then is filtered online through the plate filter box. The hydrogen content of the melt after degassing and filtration is ≤0.15ml / 100gAl, and the alkali metal Na content is ≤2ppm. S2: Continuous casting and rolling: The aluminum melt in the front box flows uniformly through the casting nozzle between the two steel belts, and the aluminum melt solidifies in the casting cavity to form a cast billet. During continuous casting, the front box temperature is maintained at 700±10℃, the casting speed is controlled at 7.2-7.8m / min, the billet thickness is controlled at 19±1mm, and the billet width is controlled at 1635±5mm. The slab enters the three-pass continuous rolling mill for rolling. The roughness of the work rolls in the first pass is 3-4µm, the rolling processing rate is controlled at 55-65%, and the slab outlet thickness is 6.7-8.5mm. The roughness of the work rolls in the second pass is 1-2µm, the rolling processing rate is controlled at 45-55%, and the slab outlet thickness is 3.3-3.8mm. The roughness of the work rolls in the third pass is 0.5-0.7µm, the rolling processing rate is controlled at 40-50%, the slab outlet thickness is 1.7-2.2mm, the outlet speed is controlled at 67-87m / min, and the final rolling temperature is controlled above 200℃. S3: Cold foil rolling: The aluminum coils after the three-pass rolling are transferred to the cold rolling unit without cooling for rolling, and the processing rate of each cold rolling pass is controlled at 50-60%; During the second rolling pass, the aluminum coil is trimmed using the trimming device provided with the rolling mill. After trimming, the aluminum coil is directly rolled into a 0.15-0.25mm cold-rolled coil. The 0.15-0.25mm cold rolled coil is foil rolled at a processing rate of 50-60%, and the aluminum foil coil with a thickness of 0.09-0.12mm is rolled. The thickness tolerance of the aluminum foil is ±4%. S4: Finished product annealing: Place the 0.09-0.12mm aluminum foil coil into the annealing furnace for finished product annealing, heat it to 220-250°C in 2 hours, keep it under negative pressure for 4-6 hours to remove oil; heat it to 260-330°C in 2-4 hours, keep it under positive pressure for 25-35 hours, then remove it from the furnace when the temperature drops to 170°C and let it cool naturally to room temperature; S5: Inspection and packaging; check that the thickness and width of the aluminum foil must not exceed the tolerance range, the end face must not have burrs, flanges, or bumps, and the layer misalignment must not exceed 0.5mm. The finished aluminum foil product is tested to have a tensile strength of 100-110Mpa and an elongation of ≥28% and is qualified. It is then packaged after passing the test.

[0007] Specifically, after adding iron agent, quick-dissolving silicon and titanium agent to the S1, electromagnetic stirring is turned on until the melt composition is uniform; after the furnace is started, the aluminum melt flows smoothly into the guide flow channel, and aluminum titanium boron wire is added to the melt at a uniform speed.

[0008] Specifically, in S2, before the steel strip contacts the aluminum liquid, it is evenly sprayed with nano-scale silicon dioxide powder by the ESP device to provide thermal insulation protection for the steel strip; and the steel strip is heated by electromagnetic induction to eliminate moisture on the surface of the steel strip.

[0009] Specifically, the ingot produced in S2 is required to have a flat shape, a thickness difference of ≤±1% throughout the roll, a layer thickness of less than 5mm, and a tower thickness of less than 10mm; the surface aluminum ash of the ingot needs to be strictly controlled to avoid serious black wire and black strip problems in the subsequent rolling process.

[0010] Specifically, in the S3, a working roll with a crown of 10µm is used during cold rolling, and the additive content in the rolling oil is ≥16%; the disc cutter is required to be wiped with a clean rag before trimming, and the trimming quality requires smooth edges, no aluminum powder, and no warping; a working roll with a crown of 8µm is used during foil rolling, and the additive content in the rolling oil is ≥12%.

[0011] Specifically, during the annealing of the finished product in S4, the axial flow fan is required to rotate at a speed of 500 r / min to achieve a temperature difference of less than 3° C. in each area of the furnace.

[0012] Due to the adoption of the above technical solution, the present invention has the following advantages: 1. By adjusting the composition, the iron and silicon alloy elements are controlled within the lower limit of the national standard, reducing the generation of coarse aluminum-iron-silicon phases and avoiding low elongation due to coarse grains after annealing of the finished product; at the same time, the zinc element is also controlled within the lower limit of the national standard to weaken the alloy strengthening effect, reduce the subsequent deformation resistance, and avoid problems such as edge cracking during continuous rolling; 2. During the cold foil rolling process, the working rolls and rolling oil indicators are adjusted to optimize process parameters to achieve direct rolling from billet to finished product. This direct rolling process is beneficial to improving the mechanical properties of the finished product and facilitating punching production for downstream customers. 3. Increase the casting speed of billet production to ensure that the final rolling temperature of the three-stage rolling product is controlled above 200°C, improve the metal plasticity, reduce deformation resistance, and facilitate subsequent cold foil rolling; 4. After the three-pass rolling mill is finished, the subsequent cold foil rolling process is quickly arranged to fully utilize the deformation heat generated by the three-pass rolling and each rolling pass to achieve high processing rate rolling in each pass; 5. Adjust the production parameters of three-roll rolling to achieve thinning of billets in three-roll rolling. The finished product can be rolled in 4 passes in the latter process, which greatly reduces the production cost. 6. Using a high proportion of 60%-70% electrolytic aluminum liquid to prepare aluminum melt and adopting appropriate melt refining process, the quality of aluminum melt can be completely equivalent to that of melt produced by using remelting aluminum ingots. This production plan can eliminate the remelting process of electrolytic aluminum liquid ingots. It is calculated that each ton of product can save about 1% of metal aluminum burnout, 30kW·h of electricity, 9-12 tons of production water and 60 cubic meters of natural gas; 7. This production plan adopts a billet direct rolling production method, rationally adjusts process parameters, and achieves high processing rate rolling. Compared with the production method of the existing technical solution that requires billet homogenization, it can save 300kW·H of homogenization annealing power consumption and reduce production time by more than 5 days, achieving efficient, short-process production and fast delivery. DETAILED DESCRIPTION

[0013] The present invention will be further explained below with reference to the embodiments, which are not intended to limit the scope of protection of the present invention. The purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention. Example 1

[0014] A method for manufacturing 7072 alloy high-performance air-conditioning foil in a low-carbon, high-efficiency and short process, comprising the following steps: S1: smelting; 60% by mass of electrolytic aluminum liquid, 30% of remelted aluminum ingots and 10% of recycled aluminum scrap are put into a smelting furnace for remelting to prepare an aluminum melt. The melt temperature of the smelting furnace is 770±5°C. Iron agent, instant silicon, titanium agent and zinc ingot are added to the smelting furnace. Electromagnetic stirring is turned on to ensure that the melt is fully stirred. The alloy composition is adjusted to meet the requirements, wherein the mass percentage of each component is: Si: 0.05%, Fe: 0.1%, Cu: 0.012%, Zn: 0.8%, Ti: 0.015%, other individual impurities ≤ 0.03%, total ≤ 0.15%, and the balance is Al; After refining, slagging and standing, aluminum melt is obtained; after starting the furnace, the aluminum melt flows smoothly into the diversion trough, and four groups of aluminum titanium boron wires are added to the melt at a uniform speed. The melt is introduced into the SNIF degassing box through the diversion trough for online degassing, and then filtered online through the plate filter box. The hydrogen content of the melt after degassing and filtration is 0.12ml / 100gAl, and the alkali metal Na content is 1ppm.

[0015] S2: Continuous casting and rolling. During continuous casting, the aluminum melt in the front box flows through the casting nozzle at a uniform speed between two steel strips. Before the steel strips come into contact with the aluminum liquid, they are sprayed with a uniform layer of nano-scale silicon dioxide powder by an ESP device to provide thermal insulation and protection. In addition, the steel strips are heated by electromagnetic induction to remove moisture from the surface. Under the combined action of two steel belts and two pairs of side blocks, the heat of the aluminum melt is carried away by the circulating cooling water inside the steel belts, and the aluminum melt solidifies in the casting cavity to form a billet. During continuous casting, the front box temperature must be maintained at 710°C, the casting speed is controlled at 7.2m / min, the billet thickness is controlled at 19mm, and the billet width is controlled at 1630mm. The ingot enters the three-pass continuous rolling mill for rolling. The roughness of the working rolls in the first pass is 3-4µm, the rolling processing rate is controlled at 55-65%, and the slab outlet thickness is 6.7mm; the roughness of the working rolls in the second pass is 1-2µm, the rolling processing rate is controlled at 45-55%, and the slab outlet thickness is 3.4mm; the roughness of the working rolls in the third pass is 0.5-0.7µm, the rolling processing rate is controlled at 40-50%, the slab outlet thickness is 1.7mm, the outlet speed is controlled at 80m / min, and the final rolling temperature is 223℃; the slab is required to have a layer string less than 5mm, a tower shape less than 10mm, a flat plate, and a thickness difference of ≤±1% for the whole roll. The surface aluminum ash is strictly controlled to avoid serious black wire and black strip problems in the subsequent rolling process.

[0016] S3: Cold foil rolling: After the three-pass rolling, the aluminum coil is quickly transferred to the cold rolling unit without cooling. During cold rolling, the work roll crown is 10µm, the additive content in the rolling oil is ≥16%, and the processing rate of each cold rolling pass is controlled at 50-60%. The specific rolling passes are: 1.7-0.8-0.37-0.18. When rolling 0.37mm, the aluminum coil is trimmed using the mill's supporting trimming device. Before trimming, the disc knife must be wiped with a clean rag. The trimming quality requires smooth edges, no aluminum powder, and no warping. The edges must be smooth and burr-free after trimming. The aluminum coils after trimming are directly rolled into 0.18mm cold-rolled coils. The 0.18mm cold-rolled coil is foil-rolled at a processing rate of 50-60%. The working roll crown is 8µm and the additive content in the rolling oil is ≥12%. The foil rolling produces an aluminum foil coil with a thickness of 0.09mm and a thickness tolerance of ±4%. The finished aluminum foil is required to have controlled surface oil content and no visible oil spots or oil marks.

[0017] S4: Finished product annealing; first seal with high-temperature resistant aluminum foil tape to ensure that there is no loose layer before loading the material rack into the furnace for annealing, place the 0.09mm aluminum foil roll into the annealing furnace for finished product annealing, the axial flow fan is required to rotate at 500r / min to achieve a temperature difference of less than 3°C in each area of the furnace; heat up to 220°C in 2 hours, keep under negative pressure for 4 hours to remove oil, heat up to 285°C in 2 hours, keep under positive pressure for 28 hours, then remove from the furnace when the furnace temperature drops to 170°C and cool naturally to room temperature.

[0018] S5: Inspection and packaging; check that the thickness and width of the aluminum foil must not exceed the tolerance range, the end face must not have burrs, flanges, or bumps, and the layer misalignment must not exceed 0.5mm. The finished aluminum foil product must have a tensile strength of 100Mpa and an elongation of 28%. It will be qualified and packaged after it is qualified. Comparative Example 1

[0019] Comparative Example 1 adopts the existing process flow of smelting → continuous casting and rolling → homogenization annealing → 9-pass cold foil rolling → finished product annealing to produce a product with a thickness of 0.095 mm corresponding to Example 1 with the following properties: tensile strength 110 / Mpa, elongation 20%. Example 2

[0020] A method for manufacturing 7072 alloy high-performance air-conditioning foil in a low-carbon, high-efficiency and short process, comprising the following steps: S1: smelting; 70% by mass of electrolytic aluminum liquid, 25% of remelted aluminum ingots and 5% of recycled aluminum scrap are put into a smelting furnace for remelting to prepare an aluminum melt. The melt temperature of the smelting furnace is 770±5°C. Iron agent, instant silicon, titanium agent and zinc ingot are added to the smelting furnace. Electromagnetic stirring is turned on to ensure that the melt is fully stirred. The alloy composition is adjusted to meet the requirements, wherein the mass percentage of each component is: Si: 0.10%, Fe: 0.15%, Cu: 0.012%, Zn: 0.9%, Ti: 0.025%, other individual impurities ≤ 0.03%, total ≤ 0.15%, and the balance is Al; After refining, slagging and standing, aluminum melt is obtained; after starting the furnace, the aluminum melt flows smoothly into the diversion trough, and four groups of aluminum titanium boron wires are added to the melt at a uniform speed. The melt is introduced into the SNIF degassing box through the diversion trough for online degassing, and then filtered online through the plate filter box. The hydrogen content of the melt after degassing and filtration is 0.15ml / 100gAl, and the alkali metal Na content is 2ppm.

[0021] S2: Continuous casting and rolling. During continuous casting, the aluminum melt in the front box flows through the casting nozzle at a uniform speed between two steel strips. Before the steel strips come into contact with the aluminum liquid, they are sprayed with a uniform layer of nano-scale silicon dioxide powder by an ESP device to provide thermal insulation and protection. In addition, the steel strips are heated by electromagnetic induction to remove moisture from the surface. Under the combined action of two steel belts and two pairs of side blocks, the heat of the aluminum melt is carried away by the circulating cooling water inside the steel belts, and the aluminum melt solidifies in the casting cavity to form a billet. During continuous casting, the front box temperature must be maintained at 690°C, the casting speed is controlled at 7.8m / min, the billet thickness is controlled at 19mm, and the billet width is controlled at 1640mm. The ingot enters the three-pass continuous rolling mill for rolling. The roughness of the working rolls in the first pass is 3-4µm, the rolling processing rate is controlled at 55-65%, and the slab outlet thickness is 8.0mm; the roughness of the working rolls in the second pass is 1-2µm, the rolling processing rate is controlled at 45-55%, and the slab outlet thickness is 3.8mm; the roughness of the working rolls in the third pass is 0.5-0.7µm, the rolling processing rate is controlled at 40-50%, the slab outlet thickness is 2.2mm, the outlet speed is controlled at 67m / min, and the final rolling temperature is 235℃; the slab is required to have a layer string less than 5mm, a tower shape less than 10mm, a flat plate, and a thickness difference of ≤±1% for the whole roll. The surface aluminum ash is strictly controlled to avoid serious black wire and black strip problems in the subsequent rolling process.

[0022] S3: Cold foil rolling: After the three-pass rolling, the aluminum coil is quickly transferred to the cold rolling unit without cooling. During cold rolling, the work roll crown is 10µm, the additive content in the rolling oil is ≥16%, and the processing rate of each cold rolling pass is controlled at 50-60%. The specific rolling passes are: 2.2-1.0-0.5-0.25. When rolling 0.5mm, the aluminum coil is trimmed using the trimming device equipped with the rolling mill; Before trimming, the disc knife must be wiped with a clean rag. The trimming quality requires smooth edges, no aluminum powder, and no warping. The edges must be smooth and burr-free after trimming. The aluminum coils after trimming are directly rolled into 0.25mm cold-rolled coils. 0.25mm cold-rolled coils are foil rolled at a processing rate of 50-60%. The working roll crown is 8µm and the additive content in the rolling oil is ≥12%. The foil rolling produces aluminum foil coils with a thickness of 0.12mm and a thickness tolerance of ±4%. The finished aluminum foil is required to have controlled surface oil content and no visible oil spots or oil marks.

[0023] S4: Annealing of finished products; first seal with high-temperature resistant aluminum foil tape to ensure that there is no loose layer before loading the material rack into the furnace for annealing, place the 0.12mm aluminum foil roll into the annealing furnace for finished product annealing, the axial flow fan is required to rotate at 500r / min to achieve a temperature difference of less than 3°C in each area of the furnace; heat up to 220°C in 2 hours, keep under negative pressure for 4 hours to remove oil, heat up to 285°C in 2 hours, keep under positive pressure for 28 hours, then remove from the furnace when the furnace temperature drops to 170°C and cool naturally to room temperature.

[0024] S5: Inspection and packaging; check that the thickness and width of the aluminum foil must not exceed the tolerance range, the end face must not have burrs, flanges, or bumps, and the layer misalignment must not exceed 0.5mm. The finished aluminum foil product must have a tensile strength of 100Mpa and an elongation of 32%. It will be qualified and packaged after it is qualified. Comparative Example 2

[0025] Comparative Example 2 adopts the existing process flow of smelting → continuous casting and rolling → homogenization annealing → 9-pass cold foil rolling → finished product annealing to produce the same 0.12 mm thick product as Example 2 with the following properties: tensile strength 95 / Mpa, elongation 27%.

[0026] Table 1 is a performance comparison table of products produced by the technical solutions of Examples 1 and 2 of the present invention and the technical solutions of Comparative Examples 1 and 2.

[0027] Table 1 Thickness / mm Tensile strength / Mpa Elongation / % Example 1 0.09 100 28 Comparative Example 1 0.095 110 20 Example 2 0.12 100 32 Comparative Example 2 0.12 95 27 From the comparison of the data in Table 1, it can be seen that the 0.09mm thick material produced by the technical solution of the present invention has a higher elongation than the 0.095mm thick material produced by the solution of Comparative Example 1. For the same 0.12mm thick material produced by Example 2 of the present invention, the elongation of the product produced by the present invention is 32%, while the elongation of the material produced by the solution of Comparative Example 2 is only 27%; In addition, the tensile strength of the materials produced by the schemes of Comparative Examples 1 and 2 is 95 and 115 MPa, respectively, while the tensile strength of the materials produced by the technical scheme of the present invention is stable at 100 MPa. The stable tensile strength makes it easier for end customers to adjust the punching molds, which is conducive to stable production and stable quality. In summary, the performance of the materials produced by the technical scheme of the present invention is better, more stable, and more suitable for customer use.

[0028] The parts not described in detail in this invention are prior art.

[0029] The embodiments selected herein for the purpose of disclosing the invention are presently considered suitable, but it should be understood that the invention is intended to include all variations and modifications of the embodiments that fall within the scope of the concept and invention.

Claims

1. A method for manufacturing 7072 alloy high-performance air conditioning foil in a low-carbon, high-efficiency and short process, characterized in that: The specific steps are: S1: Smelting; 60-70% by mass of electrolytic aluminum liquid, 20-30% of remelted aluminum ingots and 5-10% of recycled aluminum scrap are placed in a smelting furnace for remelting to prepare an aluminum melt. The melt temperature of the smelting furnace is 770±5°C. Iron agent, quick-dissolving silicon, titanium agent and zinc ingot are added to the smelting furnace to adjust the alloy composition to meet the requirements. The mass percentages of the components are as follows: Si: 0.05-0.10%, Fe: 0.1-0.15%, Cu: ≤0.02%, Zn: 0.8-0.9%, Ti: 0.015-0.025%, other individual impurities ≤0.03% and total ≤0.15%, and the balance is Al; After refining, slagging and standing, the aluminum melt is qualified and ready for furnace starting. The melt flows into the degassing box through the diversion flow channel for online degassing, and then is filtered online through the plate filter box. The hydrogen content of the melt after degassing and filtration is ≤0.15ml / 100gAl, and the alkali metal Na content is ≤2ppm. S2: Continuous casting and rolling: The aluminum melt in the front box flows uniformly through the casting nozzle between the two steel belts, and the aluminum melt solidifies in the casting cavity to form a cast billet. During continuous casting, the front box temperature is maintained at 700±10℃, the casting speed is controlled at 7.2-7.8m / min, the billet thickness is controlled at 19±1mm, and the billet width is controlled at 1635±5mm. The slab enters the three-pass continuous rolling mill for rolling. The roughness of the work rolls in the first pass is 3-4µm, the rolling processing rate is controlled at 55-65%, and the slab outlet thickness is 6.7-8.5mm. The roughness of the work rolls in the second pass is 1-2µm, the rolling processing rate is controlled at 45-55%, and the slab outlet thickness is 3.3-3.8mm. The roughness of the work rolls in the third pass is 0.5-0.7µm, the rolling processing rate is controlled at 40-50%, the slab outlet thickness is 1.7-2.2mm, the outlet speed is controlled at 67-87m / min, and the final rolling temperature is controlled above 200℃. S3: Cold foil rolling: The aluminum coils after the three-pass rolling are transferred to the cold rolling unit without cooling for rolling, and the processing rate of each cold rolling pass is controlled at 50-60%; During the second rolling pass, the aluminum coil is trimmed using the trimming device provided with the rolling mill. After trimming, the aluminum coil is directly rolled into a 0.15-0.25mm cold-rolled coil. The 0.15-0.25mm cold rolled coil is foil rolled at a processing rate of 50-60%, and the aluminum foil coil with a thickness of 0.09-0.12mm is rolled. The thickness tolerance of the aluminum foil is ±4%. S4: Finished product annealing: Place the 0.09-0.12mm aluminum foil coil into the annealing furnace for finished product annealing, heat it to 220-250°C in 2 hours, keep it under negative pressure for 4-6 hours to remove oil; heat it to 260-330°C in 2-4 hours, keep it under positive pressure for 25-35 hours, then remove it from the furnace when the temperature drops to 170°C and let it cool naturally to room temperature; S5: Inspection and packaging; check that the thickness and width of the aluminum foil must not exceed the tolerance range, the end face must not have burrs, flanges, or bumps, and the layer misalignment must not exceed 0.5mm. The finished aluminum foil product is tested to have a tensile strength of 100-110Mpa and an elongation of ≥28% and is qualified. It is then packaged after passing the test.

2. The method for manufacturing 7072 alloy high-performance air-conditioning foil by a low-carbon, high-efficiency, short-process method according to claim 1, characterized in that: After adding iron agent, quick-dissolving silicon and titanium agent into the S1, electromagnetic stirring is fully started; after starting the furnace, the aluminum melt flows smoothly into the guide flow channel, and aluminum titanium boron wire is added into the melt at a uniform speed.

3. The method for producing 7072 alloy high-performance air-conditioning foil with a low-carbon, high-efficiency, short process according to claim 1, characterized in that: In the above-mentioned S2, before the steel strip contacts the aluminum liquid, it is evenly sprayed with nano-scale silicon dioxide powder by the ESP equipment; and the steel strip is heated by electromagnetic induction.

4. The method for manufacturing 7072 alloy high-performance air-conditioning foil with low carbon and high efficiency in a short process according to claim 1 is characterized in that: The ingot produced in S2 is required to have a flat shape, a thickness difference of the entire roll ≤±1%, a layer thickness less than 5mm, and a tower thickness less than 10mm.

5. The method for manufacturing 7072 alloy high-performance air-conditioning foil with low carbon and high efficiency in a short process according to claim 1 is characterized in that: In the S3 described above, a working roll with a crown of 10µm is used during cold rolling, and the additive content in the rolling oil is ≥16%; the disc cutter is required to be wiped with a clean rag before trimming, and the trimming quality requires smooth edges, no aluminum powder, and no warping; a working roll with a crown of 8µm is used during foil rolling, and the additive content in the rolling oil is ≥12%.

6. The method for manufacturing 7072 alloy high-performance air-conditioning foil with low carbon and high efficiency in a short process according to claim 1, characterized in that: During the annealing of the finished product in S4, the axial flow fan is required to rotate at a speed of 500 r / min to achieve a temperature difference of less than 3°C in each area of the furnace.