Process for producing 8006 alloy high-strength food aluminum foil from recycled aluminum

Abstract

The application introduces a process method for producing 8006 alloy food aluminum foil by using recycled aluminum, which comprises the following steps: adding recycled aluminum solid material into a smelting furnace for smelting; setting up the parameters of a casting nozzle and a vertical plate according to the quality control requirements; homogenizing annealing the blank; cold rolling for 5 passes to a thickness of 0.48 mm; longitudinal shearing; secondary intermediate annealing; precision rolling from a thickness of 0.48 mm, rolling for 5 passes to a finished product thickness; thin shearing and finished product annealing. The application reduces the use of new aluminum resources, uses a new type of casting nozzle to produce the blank, improves the yield, reduces the production cost, reduces the blank production debugging time and the debugging times in the production process, optimizes the alloying and annealing process, ensures that the tensile strength of the finished product reaches 110-140 MPa, the elongation rate is greater than or equal to 3%, the brushing water is A grade or above, and the performance is stable.

Description

Technical Field

[0001] This invention relates to the field of aluminum foil production technology, and in particular to a process for producing 8006 alloy food aluminum foil from recycled aluminum. Background Technology

[0002] Alloy 8006 is based on alloy 8011, with a redistribution of Fe and Si content and the addition of a certain amount of Mn. This not only improves the strength of the material, but also allows Mn to act as a solid solution strengthener, increase the recrystallization temperature, refine the recrystallized grains, and improve the mechanical properties of the alloy. However, the amount of Mn must be controlled appropriately; otherwise, it easily forms a large amount of brittle compound MnAl6, making the alloy prone to cracking during deformation. In addition, Mn is prone to intragranular segregation under rapid cooling conditions, and at the same time, it causes MnAl4 to precipitate into Mn during the crystallization process. The peritectic transformation of the nAl6 phase is incomplete; this crystallization characteristic makes it difficult to obtain a uniform and fine grain structure in annealed materials; subsequent rolling processes easily lead to coarse grains, and the strips and foils exhibit tiger-skin "patina" patterns; and the following control difficulties exist in production: ① The casting and rolling zone is small, making it difficult to assemble the casting nozzle and increasing the difficulty of erecting the plate; ② The opening of the casting nozzle is small, which easily leads to color differences in production; ③ The gap between the nozzle and the roller is small, and the nozzle skin is easy to rub against the roller, which easily produces stripes and scratches in production; ④ The temperature control of subsequent annealing is strict, which easily leads to coarse grains. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a process for producing 8006 alloy food aluminum foil from recycled aluminum, thereby promoting the utilization of recycled aluminum, reducing production costs, ensuring stable product performance, and meeting quality requirements.

[0004] The technical solution adopted in this invention is: A process for producing 8006 alloy food-grade aluminum foil from recycled aluminum, comprising the following steps: S1: Smelting; Add recycled aluminum solid material to the smelting furnace for smelting. When the molten aluminum reaches a depth of 200-300mm, perform the first manual stirring for at least 5 minutes at each furnace door, and then stir every 30 minutes until fully melted. Perform manual stirring at least three times. Before the third manual stirring, sprinkle 1.1-1.5 kg / t Al slagging agent evenly into the furnace doors. After stirring, remove the slag. Turn on the electromagnetic stirrer and heat up to 725-740℃. Take a sample for composition analysis. Add the alloy according to the composition analysis results to ensure that the composition is uniform and meets the standards: iron 1.35-1.55%, silicon 0.2-0.3%, manganese 0.45-0.65%, titanium 0.01-0.04%, copper ≤0.05%, magnesium ≤0.01%, zinc ≤0.02%, other impurities individual content ≤0.02%, total impurities content ≤0.1%; Argon gas is used as a carrier, and 2.0 kg / t Al of environmentally friendly refining agent is used for powder refining. After refining, slag is removed, samples are taken, and the composition is qualified. Aluminum-titanium alloy is added through two furnace doors and stirred with electromagnetic stirring in both directions. Argon gas is used as a carrier for refining, and the temperature is controlled within the range of 745-755℃ before the furnace is turned over. The system employs a rotary blowing method for online degassing and slag removal, regularly cleans floating slag, and performs dual-stage filtration in a filter box. S2: Casting and rolling; Main casting and rolling process parameters: billet thickness 7.2±0.2mm, casting speed 700-750mm / min, front box melt temperature 695±2℃, cooling water temperature 30-40℃, cooling water pressure 0.5-0.7MPa, cooling water inlet and outlet temperature rise 1-5℃; Degassing chamber settings: temperature 725±10℃, rotor speed 460±10r / min, main gas flow rate 15±5L / min, covering gas flow rate 15±5L / min, argon pressure 0.20-0.25MPa; the degassing rotor is a silicon nitride rotor. Based on quality control requirements, the following parameters for the casting nozzle and vertical plate are defined: casting nozzle width = production billet width + 5 mm; the flow distribution method of the casting nozzle is that the spacing between the flow distribution blocks increases by 5 mm from the middle flow distribution block to the edge flow distribution block; the aluminum inlet width is 100 mm; the casting and rolling zone is 45-52 mm; the roll gap is preset to 5.2 mm; the prestress is 400 KN; the water discharge temperature is 735-740℃; and the casting nozzle opening is 8.5-9.5 mm. S3: Billet homogenization annealing; The quality of incoming materials is checked during billet annealing; the billet homogenization process is as follows: first, the furnace gas temperature is raised to 580±3℃ for 3 hours and held for 33 hours, and then the furnace gas temperature is lowered to 170±3℃ and cooled before being taken out of the furnace. S4: Rough rolling; Cold rolling is performed from a thickness of 7.2±0.2 mm in 5 passes to a thickness of 0.48 mm, with the passes being 7.2±0.2-4.2-2.4-1.4-0.8-0.48. First pass: 7.2±0.2 mm -4.2 mm, inlet tension 8±2 N / mm 2 Outlet tension 14±2 N / mm 2Rolling speed ≤380mpm, rolling oil temperature 35±10℃; Second pass: 4.2 mm - 2.4 mm, inlet tension 11±2 N / mm 2 Outlet tension 17±2 N / mm 2 Rolling speed ≤380mpm, rolling oil temperature 35±10℃; Third pass: 2.4 mm - 1.4 mm, inlet tension 14 ± 2 N / mm 2 Outlet tension 20±2 N / mm 2 Rolling speed ≤380mpm, rolling oil temperature 35±10℃; Fourth pass: 1.4 mm - 0.8 mm, inlet tension 16±2 N / mm 2 Outlet tension 22±2 N / mm 2 Rolling speed ≤700mpm, rolling oil temperature 35±10℃; Fifth pass: 0.8mm-0.48mm, inlet tension 20±2N / mm 2 Outlet tension 24±2 N / mm 2 Rolling speed ≤750mpm, rolling oil temperature 35±10℃; S5: Longitudinal shear edge; The 0.48mm thick billet is transferred to a rewinding machine for edge trimming; the rewinding machine has a winding tension of 9-17kN, a disc cutter gap of 0.028-0.033mm, a disc cutter overlap of 0.035-0.045mm, and an edge trimming speed of 180-300m / min. S6: Secondary intermediate annealing; During the second annealing, the quality of the incoming material is checked according to the quality standard; the furnace gas temperature is raised to 380±3℃ in 3 hours and held for 21 hours, then cooled to 330±3℃ in 1 hour and held for 7 hours, and finally the furnace gas temperature is lowered to 170±3℃ and cooled out of the furnace. S7: Finish rolling; The finishing rolling process starts from a thickness of 0.48 mm and proceeds through 5 passes to achieve the final thickness. The passes are 0.48-0.25-0.13-0.065-0.031-0.015 mm. First pass: 0.48mm-0.25mm, inlet tension 35±10N / mm 2 Outlet tension 30±5 N / mm 2 Rolling speed 400-600mpm, rolling oil temperature 40±10℃; Second pass: 0.25mm-0.13mm, inlet tension 35±10N / mm 2 Outlet tension 30±5 N / mm 2Rolling speed 550-850mpm, rolling oil temperature 40±10℃; Third pass: 0.013mm-0.065mm, inlet tension 35±10N / mm 2 Outlet tension 30±5 N / mm 2 Rolling speed 650-950mpm, rolling oil temperature 40±10℃; Fourth pass: 0.065mm-0.031mm, inlet tension 35±10N / mm 2 Outlet tension 30±5 N / mm 2 Rolling speed 700-1000mpm, rolling oil temperature 40±10℃; Fifth pass: 0.031mm-0.015mm, inlet tension 40±10N / mm 2 Outlet tension 35±5 N / mm 2 Rolling speed 600-900mpm, rolling oil temperature 40±10℃; S8: Thin shearing and finishing annealing; Cut aluminum coils according to process requirements, ensure end face quality, and seal firmly with high-temperature aluminum foil tape; the annealing process is as follows: raise the furnace gas temperature to 205±3℃ and hold for 19 hours, then lower the furnace gas temperature to 60±3℃ and cool out of the furnace.

[0005] Due to the adoption of the technical solution described above, the present invention has the following advantages: The process for producing 8006 alloy food-grade aluminum foil from recycled aluminum of this invention reduces the use of new aluminum resources, adopts a new type of casting nozzle flow production billet, improves the yield, reduces production costs, reduces billet production debugging time and the number of debugging times during production, and greatly improves the surface quality, meeting the quality requirements of downstream rolling processes; the optimized alloy composition and annealing process ensure that the finished product has a tensile strength of 110-140 MPa, an elongation of ≥3%, a water-brushing grade of A or above, and stable performance. Attached Figure Description

[0006] Figure 1 This is a schematic diagram of the casting nozzle distribution method in S2 of the present invention.

[0007] In the diagram, 1-aluminum inlet, 2-rear baffle, 3-side triangular baffle, 4-diverter block. Detailed Implementation

[0008] The present invention will be further explained and described below with reference to the accompanying drawings and embodiments. However, this should not be construed as limiting 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

[0009] A process for producing 8006 alloy food-grade aluminum foil from recycled aluminum, comprising the following steps: S1: Smelting; Add recycled aluminum solids to the smelting furnace for smelting. Recycled materials include, but are not limited to, 3003 alloy scrap, 3102 alloy scrap, 8011 alloy scrap, 8006 alloy scrap, and 1060 alloy scrap. Scrap materials are added in the order of lower grade scrap first and higher grade scrap last. The amount of scrap below grade four ladle is ≤30%. When the aluminum melt reaches a depth of 200-300mm, perform the first manual stirring for at least 5 minutes at each furnace door, and then stir every 30 minutes until fully melted. Perform manual stirring at least three times. Before the third manual stirring, sprinkle 1.1-1.5 kg / t Al slagging agent evenly into the furnace doors. After stirring, remove the slag.

[0010] Turn on the electromagnetic stirrer and heat up to 725-740℃. Take a sample for composition analysis. Add the alloy according to the composition analysis results to ensure that the composition is uniform and meets the standards: iron 1.35-1.55%, silicon 0.2-0.3%, manganese 0.45-0.65%, titanium 0.01-0.04%, copper ≤0.05%, magnesium ≤0.01%, zinc ≤0.02%, other impurities individual content ≤0.02%, total impurities content ≤0.1%.

[0011] Argon gas is used as a carrier, and 2.0 kg / t Al of environmentally friendly refining agent is used for powder refining. After refining, slag is removed, samples are taken, and the composition is qualified. Aluminum-titanium alloy is added through two furnace doors and stirred with electromagnetic stirring in both directions. Argon gas is used as a carrier for refining again, and the temperature is controlled within the range of 745-755℃ before the furnace is turned over. Before turning over the furnace, it must be confirmed that the composition and temperature are qualified and that the furnace is completely emptied.

[0012] The rotary blowing method is used for online degassing and slag removal. The floating slag is cleaned regularly, and the mixture undergoes two-stage filtration in a filter box with a filter mesh size of 50 mesh + 50 mesh. The smelting process ensures that the degassing and slag removal are thorough, the mixing is uniform, and the melt quality is guaranteed to be uniform and of qualified composition.

[0013] S2: Casting and rolling; Main casting and rolling process parameters: billet thickness 7.2±0.2mm, casting speed 700-750mm / min, front box melt temperature 695±2℃, cooling water temperature 30-40℃, cooling water pressure 0.5-0.7MPa, cooling water inlet and outlet temperature rise 1-5℃.

[0014] Degassing chamber settings: temperature 725±10℃, rotor speed 460±10r / min, main gas flow rate 15±5L / min, cover gas flow rate 15±5L / min, argon pressure 0.20-0.25MPa; the degassing rotor is a silicon nitride rotor.

[0015] Parameters for the casting nozzle and vertical plate are determined based on quality control requirements: Quality control requirements include: no casting and rolling stripes, visible intermediate segregation, or surface segregation on the surface; no corrosion, loose layers, dents, or rollovers; and no black spots with a diameter greater than 3mm. Each roll must be inspected under low magnification, and the hydrogen content of each roll must be ≤0.12%. The surface must not have dark black or uneven oxide scale pressed in. Export-grade aluminum-titanium-boron wire must be used at the degassing box inlet. Before loading the finished product and after the first roll is unloaded, a sample of the center segregation must be cut. Only after the center segregation sample is qualified can the finished product be loaded.

[0016] The following specific experiments were conducted when determining the parameters for the casting nozzle and the vertical plate: First test: Filter box temperature 800℃, water discharge temperature: 753℃, prestress: 600KN, roll gap preset: 4.8mm, casting and rolling zone: 45mm, casting nozzle opening: 7.5mm, casting nozzle flow distribution method, flow divider interval is 16 / 21 / 28 / 35 mm. Second test: Filter box temperature 800℃, water discharge temperature: 748℃, prestress: 600KN, roll gap preset: 5.2mm, casting and rolling zone: 45mm, casting nozzle opening: 7.5mm, casting nozzle flow distribution method, flow divider interval is 16 / 21 / 28 / 35. Third time: Filter box temperature 790℃, water discharge temperature: 735℃, prestress: 400KN, roll gap preset: 5.4mm, casting and rolling zone: 51mm, casting nozzle opening: 9mm, casting nozzle flow distribution method, flow divider interval is 20 / 30 / 40 / 50. Fourth time: Filter box temperature 780℃, water discharge temperature: 740℃, prestress: 400KN, roll gap preset: 5.2mm, casting and rolling zone: 48mm, casting nozzle opening: 9mm, casting nozzle flow distribution method, flow divider interval is 20 / 25 / 30 / 35. Fifth time: Filter box temperature 780℃, water discharge temperature: 735℃, prestress: 400KN, roll gap preset: 5.3mm, casting and rolling zone: 46mm, casting nozzle opening: 9mm, casting nozzle flow distribution method, flow divider interval is 20 / 25 / 30 / 35. In the experiment, the first time the board surface had a slight color difference and the scribing was serious, resulting in a production stoppage of 2 rolls; the second time the board surface had a serious color difference and the production was stopped immediately; the third time the board was successfully erected, but the adjustment time was too long due to a slight color difference; the fourth and fifth times the board was erected successfully and the board surface quality was good. Combination Figure 1 As shown, the optimal casting nozzle parameters are detailed in the table below: 100mm 50mm 70*140mm 400mm 140mm 120 / 100mm 20mm 25mm 30mm 35mm 50-60mm Therefore, the optimal parameters for the casting nozzle and the vertical plate are determined as follows: The nozzle width is equal to the width of the production billet plus 5 mm. The nozzle flow distribution method is that the spacing between the flow dividers increases by 5 mm from the middle flow divider to the edge flow divider, which are 20 / 25 / 30 / 35 mm respectively. The aluminum inlet width is 100 mm. The casting and rolling zone is 45-52 mm. The roll gap is preset to 5.2 mm. The prestress is 400 KN. The water discharge temperature is 735-740℃. The nozzle opening is 8.5-9.5 mm.

[0017] S3: Billet homogenization annealing; The quality of incoming materials is checked during billet annealing; the billet homogenization process is as follows: first, the furnace gas temperature is raised to 580±3℃ for 3 hours and held for 33 hours, and then the furnace gas temperature is lowered to 170±3℃ and cooled before being taken out of the furnace.

[0018] S4: Rough rolling; Cold rolling is performed from a thickness of 7.2±0.2 mm in 5 passes to a thickness of 0.48 mm, with the passes being 7.2±0.2-4.2-2.4-1.4-0.8-0.48. First pass: 7.2±0.2 mm -4.2 mm, inlet tension 8±2 N / mm 2 Outlet tension 14±2 N / mm 2 Rolling speed ≤380mpm, rolling oil temperature 35±10℃; Second pass: 4.2 mm - 2.4 mm, inlet tension 11±2 N / mm 2 Outlet tension 17±2 N / mm 2 Rolling speed ≤380mpm, rolling oil temperature 35±10℃; Third pass: 2.4 mm - 1.4 mm, inlet tension 14 ± 2 N / mm 2 Outlet tension 20±2 N / mm 2 Rolling speed ≤380mpm, rolling oil temperature 35±10℃; Fourth pass: 1.4 mm - 0.8 mm, inlet tension 16±2 N / mm 2 Outlet tension 22±2 N / mm 2 Rolling speed ≤700mpm, rolling oil temperature 35±10℃; Fifth pass: 0.8mm-0.48mm, inlet tension 20±2N / mm 2 Outlet tension 24±2 N / mm 2 Rolling speed ≤750mpm, rolling oil temperature 35±10℃.

[0019] S5: Longitudinal shear edge; The 0.48mm thick billet is transferred to a rewinding machine for edge trimming; the rewinding machine has a winding tension of 9-17kN, a disc cutter gap of 0.028-0.033mm, a disc cutter overlap of 0.035-0.045mm, and an edge trimming speed of 180-300m / min.

[0020] S6: Secondary intermediate annealing; During the second annealing, the quality of the incoming material is checked according to the quality standards. The condition of the incoming material end face is checked, whether the end cap is made of high-temperature tape and whether it is firm, whether there is any collision between aluminum coils, and whether there is any aluminum foil stuck on the circulating fan cover of the furnace. If there is, the aluminum foil must be cleaned before the material can be put into the furnace for annealing. The furnace gas temperature is raised to 380±3℃ for 3 hours and held for 21 hours. Then it is cooled to 330±3℃ for 1 hour and held for 7 hours. Finally, the furnace gas temperature is lowered to 170±3℃ and the material is cooled and taken out of the furnace.

[0021] S7: Finish rolling; The finishing rolling process starts from a thickness of 0.48 mm and proceeds through 5 passes to achieve the final thickness. The passes are 0.48-0.25-0.13-0.065-0.031-0.015 mm. First pass: 0.48mm-0.25mm, inlet tension 35±10N / mm 2 Outlet tension 30±5 N / mm 2 Rolling speed 400-600mpm, rolling oil temperature 40±10℃; Second pass: 0.25mm-0.13mm, inlet tension 35±10N / mm 2 Outlet tension 30±5 N / mm 2 Rolling speed 550-850mpm, rolling oil temperature 40±10℃; Third pass: 0.013mm-0.065mm, inlet tension 35±10N / mm 2 Outlet tension 30±5 N / mm 2 Rolling speed 650-950mpm, rolling oil temperature 40±10℃; Fourth pass: 0.065mm-0.031mm, inlet tension 35±10N / mm 2 Outlet tension 30±5 N / mm 2 Rolling speed 700-1000mpm, rolling oil temperature 40±10℃; Fifth pass: 0.031mm-0.015mm, inlet tension 40±10N / mm 2 Outlet tension 35±5 N / mm 2 The rolling speed is 600-900mpm and the rolling oil temperature is 40±10℃.

[0022] S8: Thin shearing and finished product annealing; Slit aluminum coils according to process requirements. During slitting, all guide rollers in the guide path must be cleaned with alcohol or acetone. Ensure that the surface of the aluminum coil is free of marks, aluminum residue, scratches, and abrasions. The end face must not have burrs, pyramidal shapes, wavy edges, or small ripples on the edge. Slit aluminum coils must not be placed directly on the ground; cardboard must be placed on the floor. During slitting, check the surface of the aluminum foil for oil stains. Coils with oil stains on the surface must not be sent to the annealing process.

[0023] The cut rolls must have clean and tidy ends; the batch number and specifications of the cut rolls must be written on the surface of the aluminum rolls with chalk; the cut rolls must be sealed firmly with high-temperature aluminum foil tape to prevent them from loosening during annealing.

[0024] The finished product annealing process is as follows: the furnace gas temperature is raised to 205±3℃ and held for 19 hours, and then the furnace gas temperature is lowered to 60±3℃ to cool and remove the product from the furnace.

[0025] After the finished product is completed, it will be inspected and packaged. During inspection, the main checks are that the aluminum foil thickness and width must not exceed the tolerance range, and the end face must be free of burrs, flanging, and damage; misalignment must not exceed 0.5mm. The sleeve specifications and material must meet customer requirements, with each side of the sleeve extending 5mm beyond the aluminum foil end face; the tensile strength must be 110-140Mpa, the elongation ≥3%, and the surface water treatment must reach Grade A or above; after passing inspection, it will be packaged according to household foil packaging requirements.

[0026] The parts of this invention not described in detail are prior art.

[0027] The embodiments selected herein for the purpose of disclosing the inventive objectives are currently considered suitable; however, it should be understood that the invention is intended to include all variations and modifications of the embodiments that fall within the scope of this concept and invention.

Claims

1. A process for producing 8006 alloy food-grade aluminum foil from recycled aluminum, characterized in that, The specific steps include the following: S1: Smelting; Add recycled aluminum solid material to the smelting furnace for smelting. When the molten aluminum reaches a depth of 200-300mm, perform the first manual stirring for at least 5 minutes at each furnace door, and then stir every 30 minutes until fully melted. Perform manual stirring at least three times. Before the third manual stirring, sprinkle 1.1-1.5 kg / t Al slagging agent evenly into the furnace doors. After stirring, remove the slag. Turn on the electromagnetic stirrer and heat up to 725-740℃. Take a sample for composition analysis. Add the alloy according to the composition analysis results to ensure that the composition is uniform and meets the standards: iron 1.35-1.55%, silicon 0.2-0.3%, manganese 0.45-0.65%, titanium 0.01-0.04%, copper ≤0.05%, magnesium ≤0.01%, zinc ≤0.02%, other impurities individual content ≤0.02%, total impurities content ≤0.1%; Argon gas is used as a carrier, and 2.0 kg / t Al of environmentally friendly refining agent is used for powder refining. After refining, slag is removed, samples are taken, and the composition is qualified. Aluminum-titanium alloy is added through two furnace doors and stirred with electromagnetic stirring in both directions. Argon gas is used as a carrier for refining, and the temperature is controlled within the range of 745-755℃ before the furnace is turned over. The system employs a rotary blowing method for online degassing and slag removal, regularly cleans floating slag, and performs dual-stage filtration in a filter box. S2: Casting and rolling; Main casting and rolling process parameters: billet thickness 7.2±0.2mm, casting speed 700-750mm / min, front box melt temperature 695±2℃, cooling water temperature 30-40℃, cooling water pressure 0.5-0.7MPa, cooling water inlet and outlet temperature rise 1-5℃; Degassing chamber settings: temperature 725±10℃, rotor speed 460±10r / min, main gas flow rate 15±5L / min, covering gas flow rate 15±5L / min, argon pressure 0.20-0.25MPa; the degassing rotor is a silicon nitride rotor. Based on quality control requirements, the following parameters for the casting nozzle and vertical plate are defined: casting nozzle width = production billet width + 5mm; the flow distribution method of the casting nozzle is that the spacing between the flow dividers increases by 5mm from the middle flow divider to the edge flow divider; the aluminum inlet width is 100mm; the casting and rolling zone is 45-52mm; the roll gap is preset to 5.2mm; the prestress is 400KN; the water discharge temperature is 735-740℃; and the casting nozzle opening is 8.5-9.5mm. S3: Billet homogenization annealing; The quality of incoming materials is checked during billet annealing; the billet homogenization process is as follows: first, the furnace gas temperature is raised to 580±3℃ for 3 hours and held for 33 hours, and then the furnace gas temperature is lowered to 170±3℃ and cooled before being taken out of the furnace. S4: Rough rolling; Cold rolling is performed from a thickness of 7.2±0.2mm, with 5 passes to a thickness of 0.48mm. The passes are 7.2±0.2-4.2-2.4-1.4-0.8-0.

48. First pass: 7.2±0.2mm-4.2mm, inlet tension 8±2N / mm2, outlet tension 14±2N / mm2, rolling speed ≤380mpm, rolling oil temperature 35±10℃; Second pass: 4.2mm-2.4mm, inlet tension 11±2N / mm2, outlet tension 17±2N / mm2, rolling speed ≤380mpm, rolling oil temperature 35±10℃; Third pass: 2.4mm-1.4mm, inlet tension 14±2N / mm2, outlet tension 20±2N / mm2, rolling speed ≤380mpm, rolling oil temperature 35±10℃; Fourth pass: 1.4mm-0.8mm, inlet tension 16±2N / mm2, outlet tension 22±2N / mm2, rolling speed ≤700mpm, rolling oil temperature 35±10℃; Fifth pass: 0.8mm-0.48mm, inlet tension 20±2N / mm2, outlet tension 24±2N / mm2, rolling speed ≤750mpm, rolling oil temperature 35±10℃; S5: Longitudinal shear edge; The 0.48mm thick billet is transferred to a rewinding machine for edge trimming; the rewinding machine has a winding tension of 9-17kN, a disc cutter gap of 0.028-0.033mm, a disc cutter overlap of 0.035-0.045mm, and an edge trimming speed of 180-300m / min. S6: Secondary intermediate annealing; During the second annealing, the quality of the incoming material is checked according to the quality standard; the furnace gas temperature is raised to 380±3℃ in 3 hours and held for 21 hours, then cooled to 330±3℃ in 1 hour and held for 7 hours, and finally the furnace gas temperature is lowered to 170±3℃ and cooled out of the furnace. S7: Finish rolling; The finishing rolling process starts from a thickness of 0.48 mm and proceeds through 5 passes to achieve the final thickness. The passes are 0.48-0.25-0.13-0.065-0.031-0.015 mm. First pass: 0.48mm-0.25mm, inlet tension 35±10N / mm2, outlet tension 30±5N / mm2, rolling speed 400-600mpm, rolling oil temperature 40±10℃; Second pass: 0.25mm-0.13mm, inlet tension 35±10N / mm2, outlet tension 30±5N / mm2, rolling speed 550-850mpm, rolling oil temperature 40±10℃; Third pass: 0.013mm-0.065mm, inlet tension 35±10N / mm2, outlet tension 30±5N / mm2, rolling speed 650-950mpm, rolling oil temperature 40±10℃; Fourth pass: 0.065mm-0.031mm, inlet tension 35±10N / mm2, outlet tension 30±5N / mm2, rolling speed 700-1000mpm, rolling oil temperature 40±10℃; Fifth pass: 0.031mm-0.015mm, inlet tension 40±10N / mm2, outlet tension 35±5N / mm2, rolling speed 600-900mpm, rolling oil temperature 40±10℃; S8: Thin shearing and finishing annealing; Cut aluminum coils according to process requirements, ensure end face quality, and seal firmly with high-temperature aluminum foil tape; the annealing process is as follows: raise the furnace gas temperature to 205±3℃ and hold for 19 hours, then lower the furnace gas temperature to 60±3℃ and cool out of the furnace.

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