A method for producing an aluminum-magnesium alloy cold-rolled coil

Abstract

The application relates to a production method of an aluminum-magnesium alloy cold-rolled coil, and the technological process is as follows: smelting-casting-sawing-milling-heating-hot rolling-cold rolling-cleaning-annealing-drawing and straightening; the mechanical crown of the roller used in the cold rolling step is 0.10-0.15 mm, the roller type curve is sin70-75 DEG, and the pass processing rate is 25-30%; the crown in the strip after rolling is 0-0.02%; the crown in the cold-rolled strip is controlled, the middle crown can be effectively avoided from being too large, the middle part of the coil is not too tight after the coil is wound, the middle part is prone to layer dislocation during transportation, and white spot defects are generated; in the drawing and straightening step, the cleaning oil with a flash point of 40-60 DEG C is sprayed at the reel of the drawing and straightening machine, the oil spraying amount is 1.0-2.0 g / m 2 ; the finished product coil diameter is less than or equal to 1350 mm; the surface spraying cleaning oil can play a role in layer protection and avoid layer dislocation; through the synchronous optimization of the cold rolling step and the drawing and straightening step, the surface white spot defects of the generated product are effectively solved.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy sheet processing technology, and specifically to a method for producing cold-rolled aluminum-magnesium alloy coils. Background Technology

[0002] Aluminum-magnesium alloy is the most widely used type of rust-resistant aluminum. This alloy has high strength, especially fatigue strength; high plasticity and corrosion resistance; it cannot be strengthened by heat treatment; its plasticity is good during semi-cold work hardening, but low during cold work hardening; it has good corrosion resistance, good weldability, poor machinability, and can be polished. Aluminum-magnesium alloy strip is mainly used in chassis and cabinets, mobile phone and digital product components, instruments, etc., where extremely high surface quality requirements are necessary. With the intensification of market competition, end customers have increasingly stringent requirements for product surface quality. Inspection methods have changed from visual inspection at a distance of 1 meter under natural light to visual inspection at a distance of 200-300 mm under strong light. This has led to some minor defects, such as white spots, failing surface quality inspection.

[0003] Currently, the production process for aluminum alloy thin strip is as follows: smelting - casting - sawing - milling - heating - hot rolling - cold rolling - cleaning - annealing - tension leveling. This is currently the only production method that can stably produce 5052 alloy strip. However, products produced using this method are prone to white spot defects on their surface. The cause of white spot defects is slight interlayer misalignment during transportation of the finished cold-rolled aluminum-magnesium alloy strip after tension leveling.

[0004] A method for producing high-strength, high-bending-performance 5052 aluminum alloy cold-rolled sheet and strip, patent publication number CN117187636A, includes the following steps: melting and casting → sawing → milling → heating → hot rolling → cold rolling → annealing → leveling; the mass percentage of the aluminum alloy chemical composition is: Si≤0.20%, Fe≤0.30%, Cu≤0.10%, Mn0.05~0.10%, Mg2.70~2.80%, Cr0.15~0.20%, Zn≤0.10%, Ti0.01~0.05%, other impurity elements ≤0.05% individually, other impurity elements ≤0.15% in total, with the remainder being Al; the hot rolling final rolling temperature is 270~300℃; the total cold rolling processing rate is ≥70%; the annealing temperature is 240~260℃, and the holding time is 2~4 hours. By rationally matching the alloy element content, hot rolling final rolling temperature, cold rolling total processing rate, and annealing process, high strength, good plasticity, and bending properties of finished strips and sheets are achieved with fewer production steps and lower production costs. However, this method still suffers from the problem of white spot defects easily appearing on the surface of the produced products.

[0005] To address the shortcomings of existing technologies, this invention employs a hot rolling method to produce cold-rolled aluminum-magnesium alloy coils, thus resolving the white spot defect on the surface. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method for producing aluminum-magnesium alloy cold-rolled coils that do not produce white spot defects during transportation and can meet the surface quality requirements of end users.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a method for producing cold-rolled aluminum-magnesium alloy coils, wherein the process flow of the method is: melting - casting - sawing - milling - heating - hot rolling - cold rolling - cleaning - annealing - tension leveling; the cold rolling step is characterized by: the mechanical crown of the rolls used being 0.10-0.15 mm, the roll profile curve being sin70-75°, and the pass processing rate being 25-30%; the crown of the strip after rolling being 0-0.02%;

[0008] The tension straightening process is as follows: the cleaned and annealed roll material is subjected to tension straightening production; cleaning oil with a flash point of 40-60℃ is sprayed at the roll shaft of the tension straightening machine, and the oil spraying amount is 1.0-2.0 g / m. 2 Finished roll diameter ≤ 1350mm.

[0009] Furthermore, the cold rolling process is as follows: the mechanical crown of the rolls used is 0.12-0.15 mm, the roll profile curve is sin70-75°, and the pass processing rate is 27-30%; the crown of the strip after rolling is 0.01-0.02%.

[0010] Furthermore, the process of the tension straightening step is as follows: the cleaned and annealed roll material is subjected to tension straightening production, and cleaning oil with a flash point of 50-60℃ is sprayed at the roll shaft of the tension straightening machine, with an oil spraying amount of 1.5-2.0 g / m. 2 Finished roll diameter ≤ 1350mm.

[0011] Furthermore, in the smelting step, the mass percentage of the aluminum-magnesium alloy chemical composition is as follows: Si≤0.20%, Fe≤0.30%, Cu≤0.10%, Mn 0.05~0.10%, Mg 2.70~2.80%, Cr 0.15~0.20%, Zn≤0.10%, Ti 0.01~0.05%, other impurity elements individually ≤0.05%, other impurity elements total ≤0.15%, and the remainder is Al.

[0012] Furthermore, the heating temperature in the heating step is 480–510°C.

[0013] Furthermore, the heating and heat preservation time of the heating step is 2 to 8 hours.

[0014] Furthermore, in the hot rolling step, the final hot rolling temperature is 270–300°C.

[0015] Furthermore, in the hot rolling step, the aluminum-magnesium alloy ingot is hot rolled to 3.0–5.0 mm.

[0016] Furthermore, in the cold rolling step, the total cold rolling rate is ≥70%.

[0017] Furthermore, in the annealing step, the annealing temperature is 240–260°C, and the annealing holding time is 2–4 hours.

[0018] This invention discloses a method for producing cold-rolled aluminum-magnesium alloy coils, focusing on optimizing the cold rolling and tension leveling steps. In the cold rolling step, the mechanical crown of the rolls is 0.10–0.15 mm, the roll profile is sin70–75°, and the pass yield is 25–30%. The crown of the rolled strip is 0–0.02%. Controlling the crown of the cold-rolled strip effectively prevents excessive crown from causing the coil to be too tight in the center after winding, which can easily lead to interlayer misalignment and white spot defects during transportation. In the tension leveling step, cleaning oil with a flash point of 40–60°C is sprayed at the tension leveler's coil shaft at a rate of 1.0–2.0 g / m. 2 Finished coil diameter ≤ 1350mm; Surface spraying with cleaning oil can provide interlayer protection and prevent interlayer misalignment; Using a flash point of 40~60℃ and controlling the amount of oil sprayed, the strip is effectively protected while the oil can evaporate before the customer uses it, without affecting the customer's subsequent use; Controlling the finished coil diameter can reduce the shaking during the transportation of aluminum coils and prevent interlayer misalignment; Through the simultaneous optimization of the cold rolling and tension leveling steps, the white spot defect on the surface of the produced product is effectively solved.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. The production method of aluminum-magnesium alloy cold-rolled coil disclosed in this invention can effectively solve the white spot defect on the surface of the produced product; so that the produced aluminum-magnesium alloy cold-rolled strip does not produce white spot defects during transportation, and can meet the surface quality requirements of end users.

[0021] 2. The production method of aluminum-magnesium alloy cold-rolled coil disclosed in this invention is simple to operate, has low production and processing costs, and can effectively enhance the market competitiveness of the product. Attached Figure Description

[0022] Figure 1 The image shows a micrograph of the aluminum-magnesium alloy cold-rolled coil prepared in Comparative Example 1 of this invention. As can be seen from the micrograph, the aluminum-magnesium alloy cold-rolled coil prepared in Comparative Example 1 has white spot defects. Detailed Implementation

[0023] The following embodiments can help those skilled in the art to more fully understand the present invention, but should not be construed as limiting the present invention in any way.

[0024] This invention discloses a method for producing cold-rolled aluminum-magnesium alloy coils. In the smelting step, the mass percentage of the aluminum-magnesium alloy chemical composition is as follows: Si ≤ 0.20%, Fe ≤ 0.30%, Cu ≤ 0.10%, Mn 0.05–0.10%, Mg 2.70–2.80%, Cr 0.15–0.20%, Zn ≤ 0.10%, Ti 0.01–0.05%, other impurity elements individually ≤ 0.05%, total other impurity elements ≤ 0.15%, and the remainder is Al. The composition of the aluminum-magnesium alloy chemical composition can be adjusted according to actual conditions.

[0025] Example 1

[0026] A method for producing cold-rolled aluminum-magnesium alloy coils includes the following steps: (1) smelting and casting; (2) sawing and milling; (3) heating; (4) hot rolling; (5) cold rolling; (6) cleaning, annealing, and tension leveling;

[0027] (1) Smelting and casting: The raw materials are mixed according to the following mass percentages; the prepared raw materials are added to the smelting furnace and mixed evenly before being smelted into liquid aluminum alloy to obtain aluminum-magnesium alloy melt. The aluminum-magnesium alloy melt is transferred to the holding furnace for refining. The refining time is 30 minutes. The refined aluminum-magnesium alloy melt is cast into aluminum-magnesium alloy ingots with a thickness of 300 mm.

[0028]

[0029] (2) Sawing and milling: Sawing and milling the aluminum-magnesium alloy ingot to obtain a milled aluminum-magnesium alloy ingot;

[0030] (3) Heating: The milled aluminum-magnesium alloy ingot is sent into a heating furnace and kept at 480°C for 8 hours to obtain a heat-treated aluminum-magnesium alloy ingot.

[0031] (4) Hot rolling: The aluminum alloy ingot that has undergone heat treatment is hot rolled to 3.0 mm. The final hot rolling temperature is 270°C to obtain hot rolled coil.

[0032] (5) Cold rolling: The hot-rolled coil is cold-rolled, and the mechanical crown of the rolls used is 0.10 mm, the roll profile curve is sin70°, and the pass processing rate is 25%; the crown of the strip after rolling is 0.01%; the total cold rolling processing rate is ≥70%; and a cold-rolled coil is obtained.

[0033] (6) Cleaning, annealing, and tension straightening: The cold-rolled coil is sequentially cleaned, annealed, and tension straightened; the annealing temperature is 240℃, and the annealing holding time is 2 hours; the cleaned and annealed coil is then subjected to tension straightening production, with cleaning oil with a flash point of 40℃ sprayed at the coil shaft of the tension straightening machine at a spraying rate of 1.0 g / m. 2Finished roll diameter ≤ 1350mm.

[0034]

[0035] As can be seen from the data in the table above, the method of this application achieves the goal of effectively solving the white spot defect on the surface of the produced product by simultaneously optimizing the cold rolling step and the tension leveling step.

[0036] Example 2

[0037] A method for producing cold-rolled aluminum-magnesium alloy coils includes the following steps: (1) smelting and casting; (2) sawing and milling; (3) heating; (4) hot rolling; (5) cold rolling; (6) cleaning, annealing, and tension leveling;

[0038] (1) Smelting and casting: The raw materials are mixed according to the following mass percentages; the prepared raw materials are added to the smelting furnace and mixed evenly before being smelted into liquid aluminum alloy to obtain aluminum-magnesium alloy melt. The aluminum-magnesium alloy melt is transferred to the holding furnace for refining. The refining time is 30 minutes. The refined aluminum-magnesium alloy melt is cast into aluminum-magnesium alloy ingots with a thickness of 300 mm.

[0039]

[0040] (2) Sawing and milling: Sawing and milling the aluminum-magnesium alloy ingot to obtain a milled aluminum-magnesium alloy ingot;

[0041] (3) Heating: The milled aluminum-magnesium alloy ingot is sent into a heating furnace and kept at 480°C for 2 hours to obtain a heat-treated aluminum-magnesium alloy ingot.

[0042] (4) Hot rolling: The heat-treated aluminum alloy ingot is hot rolled to 5.0 mm, and the final hot rolling temperature is 300℃ to obtain hot rolled coil.

[0043] (5) Cold rolling: The hot-rolled coil is cold-rolled, and the mechanical crown of the rolls used is 0.15 mm, the roll profile curve is sin75°, and the pass processing rate is 30%; the crown of the strip after rolling is 0.02%; the total cold rolling processing rate is ≥70%; and a cold-rolled coil is obtained.

[0044] (6) Cleaning, annealing, and tension straightening: The cold-rolled coil is sequentially cleaned, annealed, and tension straightened; the annealing temperature is 260℃, and the annealing holding time is 4 hours; the cleaned and annealed coil is then subjected to tension straightening production, with cleaning oil with a flash point of 60℃ sprayed at the tension straightening machine shaft at a spray rate of 2.0 g / m. 2 Finished roll diameter ≤ 1350mm.

[0045]

[0046] As can be seen from the data in the table above, the method of this application achieves the goal of effectively solving the white spot defect on the surface of the produced product by simultaneously optimizing the cold rolling step and the tension leveling step.

[0047] Example 3

[0048] A method for producing cold-rolled aluminum-magnesium alloy coils includes the following steps: (1) smelting and casting; (2) sawing and milling; (3) heating; (4) hot rolling; (5) cold rolling; (6) cleaning, annealing, and tension leveling;

[0049] (1) Smelting and casting: The raw materials are mixed according to the following mass percentages; the prepared raw materials are added to the smelting furnace and mixed evenly before being smelted into liquid aluminum alloy to obtain aluminum-magnesium alloy melt. The aluminum-magnesium alloy melt is transferred to the holding furnace for refining. The refining time is 30 minutes. The refined aluminum-magnesium alloy melt is cast into aluminum-magnesium alloy ingots with a thickness of 300 mm.

[0050]

[0051] (2) Sawing and milling: Sawing and milling the aluminum-magnesium alloy ingot to obtain a milled aluminum-magnesium alloy ingot;

[0052] (3) Heating: The milled aluminum-magnesium alloy ingot is sent into a heating furnace and kept at 500°C for 6 hours to obtain a heat-treated aluminum-magnesium alloy ingot.

[0053] (4) Hot rolling: The aluminum alloy ingot that has undergone heat treatment is hot rolled to 4.0 mm. The final hot rolling temperature is 280°C to obtain hot rolled coil.

[0054] (5) Cold rolling: The hot-rolled coil is cold-rolled, and the mechanical crown of the rolls used is 0.12 mm, the roll profile curve is sin70°, and the pass processing rate is 27%; the crown of the strip after rolling is 0.01%; the total cold rolling processing rate is ≥70%; and a cold-rolled coil is obtained.

[0055] (6) Cleaning, annealing, and tension straightening: The cold-rolled coil is sequentially cleaned, annealed, and tension straightened; the annealing temperature is 250℃, and the annealing holding time is 3 hours; the cleaned and annealed coil is then subjected to tension straightening production, and cleaning oil with a flash point of 50℃ is sprayed at the coil shaft of the tension straightening machine at a spraying rate of 1.5g / m. 2 Finished roll diameter ≤ 1350mm.

[0056]

[0057]

[0058] As can be seen from the data in the table above, the method of this application achieves the goal of effectively solving the white spot defect on the surface of the produced product by simultaneously optimizing the cold rolling step and the tension leveling step.

[0059] Example 4

[0060] A method for producing cold-rolled aluminum-magnesium alloy coils includes the following steps: (1) smelting and casting; (2) sawing and milling; (3) heating; (4) hot rolling; (5) cold rolling; (6) cleaning, annealing, and tension leveling;

[0061] (1) Smelting and casting: The raw materials are mixed according to the following mass percentages; the prepared raw materials are added to the smelting furnace and mixed evenly before being smelted into liquid aluminum alloy to obtain aluminum-magnesium alloy melt. The aluminum-magnesium alloy melt is transferred to the holding furnace for refining. The refining time is 30 minutes. The refined aluminum-magnesium alloy melt is cast into aluminum-magnesium alloy ingots with a thickness of 300 mm.

[0062]

[0063] (2) Sawing and milling: Sawing and milling the aluminum-magnesium alloy ingot to obtain a milled aluminum-magnesium alloy ingot;

[0064] (3) Heating: The milled aluminum-magnesium alloy ingot is sent into a heating furnace and kept at 500°C for 6 hours to obtain a heat-treated aluminum-magnesium alloy ingot.

[0065] (4) Hot rolling: The aluminum alloy ingot that has undergone heat treatment is hot rolled to 4.0 mm. The final hot rolling temperature is 280°C to obtain hot rolled coil.

[0066] (5) Cold rolling: The hot-rolled coil is cold-rolled, and the mechanical crown of the rolls used is 0.12 mm, the roll profile curve is sin70°, and the pass processing rate is 27%; the crown of the strip after rolling is 0.01%; the total cold rolling processing rate is ≥70%; and a cold-rolled coil is obtained.

[0067] (6) Cleaning, annealing, and tension straightening: The cold-rolled coil is sequentially cleaned, annealed, and tension straightened; the annealing temperature is 250℃, and the annealing holding time is 3 hours; the cleaned and annealed coil is then subjected to tension straightening production, and cleaning oil with a flash point of 50℃ is sprayed at the coil shaft of the tension straightening machine at a spraying rate of 1.5g / m. 2 Finished roll diameter ≤ 1350mm.

[0068]

[0069]

[0070] As can be seen from the data in the table above, the method of this application achieves the goal of effectively solving the white spot defect on the surface of the produced product by simultaneously optimizing the cold rolling step and the tension leveling step.

[0071] Comparative Example 1

[0072] A method for producing cold-rolled aluminum-magnesium alloy coils includes the following steps: (1) smelting and casting; (2) sawing and milling; (3) heating; (4) hot rolling; (5) cold rolling; (6) cleaning, annealing, and tension leveling;

[0073] (1) Smelting and casting: The raw materials are mixed according to the following mass percentages; the prepared raw materials are added to the smelting furnace and mixed evenly before being smelted into liquid aluminum alloy to obtain aluminum-magnesium alloy melt. The aluminum-magnesium alloy melt is transferred to the holding furnace for refining. The refining time is 30 minutes. The refined aluminum-magnesium alloy melt is cast into aluminum-magnesium alloy ingots with a thickness of 300 mm.

[0074]

[0075] (2) Sawing and milling: Sawing and milling the aluminum-magnesium alloy ingot to obtain a milled aluminum-magnesium alloy ingot;

[0076] (3) Heating: The milled aluminum-magnesium alloy ingot is sent into a heating furnace and kept at 500°C for 6 hours to obtain a heat-treated aluminum-magnesium alloy ingot.

[0077] (4) Hot rolling: The aluminum alloy ingot that has undergone heat treatment is hot rolled to 4.0 mm. The final hot rolling temperature is 280°C to obtain hot rolled coil.

[0078] (5) Cold rolling: The hot-rolled coil is cold-rolled, and the mechanical crown of the rolls used is 0.07 mm, the roll profile curve is sin55°, and the pass processing rate is 27%; the total cold rolling processing rate is ≥70%; and a cold-rolled coil is obtained.

[0079] (6) Cleaning, annealing, and tension straightening: The cold-rolled coil is sequentially cleaned, annealed, and tension straightened; the annealing temperature is 250℃, and the annealing holding time is 3 hours; the cleaned and annealed coil is then subjected to tension straightening production, and cleaning oil with a flash point of 50℃ is sprayed at the coil shaft of the tension straightening machine at a spraying rate of 1.5g / m. 2 Finished roll diameter ≤ 1350mm.

[0080]

[0081]

[0082] As can be seen from the data in the table above, the method in this embodiment cannot solve the problem of white spot defects on the surface of the produced product.

[0083] Comparative Example 2

[0084] A method for producing cold-rolled aluminum-magnesium alloy coils includes the following steps: (1) smelting and casting; (2) sawing and milling; (3) heating; (4) hot rolling; (5) cold rolling; (6) cleaning, annealing, and tension leveling;

[0085] (1) Smelting and casting: The raw materials are mixed according to the following mass percentages; the prepared raw materials are added to the smelting furnace and mixed evenly before being smelted into liquid aluminum alloy to obtain aluminum-magnesium alloy melt. The aluminum-magnesium alloy melt is transferred to the holding furnace for refining. The refining time is 30 minutes. The refined aluminum-magnesium alloy melt is cast into aluminum-magnesium alloy ingots with a thickness of 300 mm.

[0086]

[0087] (2) Sawing and milling: Sawing and milling the aluminum-magnesium alloy ingot to obtain a milled aluminum-magnesium alloy ingot;

[0088] (3) Heating: The milled aluminum-magnesium alloy ingot is sent into a heating furnace and kept at 500°C for 6 hours to obtain a heat-treated aluminum-magnesium alloy ingot.

[0089] (4) Hot rolling: The aluminum alloy ingot that has undergone heat treatment is hot rolled to 4.0 mm. The final hot rolling temperature is 280°C to obtain hot rolled coil.

[0090] (5) Cold rolling: The hot-rolled coil is cold-rolled, and the mechanical crown of the rolls used is 0.22 mm, the roll profile curve is sin80°, and the pass processing rate is 27%; the total cold rolling processing rate is ≥70%; and a cold-rolled coil is obtained.

[0091] (6) Cleaning, annealing, and tension straightening: The cold-rolled coil is sequentially cleaned, annealed, and tension straightened; the annealing temperature is 250℃, and the annealing holding time is 3 hours; the cleaned and annealed coil is then subjected to tension straightening production, and cleaning oil with a flash point of 50℃ is sprayed at the coil shaft of the tension straightening machine at a spraying rate of 1.5g / m. 2 Finished roll diameter ≤ 1350mm.

[0092]

[0093] As can be seen from the data in the table above, the method in this embodiment cannot solve the problem of white spot defects on the surface of the produced product.

[0094] Comparative Example 3

[0095] A method for producing cold-rolled aluminum-magnesium alloy coils includes the following steps: (1) smelting and casting; (2) sawing and milling; (3) heating; (4) hot rolling; (5) cold rolling; (6) cleaning, annealing, and tension leveling;

[0096] (1) Smelting and casting: The raw materials are mixed according to the following mass percentages; the prepared raw materials are added to the smelting furnace and mixed evenly before being smelted into liquid aluminum alloy to obtain aluminum-magnesium alloy melt. The aluminum-magnesium alloy melt is transferred to the holding furnace for refining. The refining time is 30 minutes. The refined aluminum-magnesium alloy melt is cast into aluminum-magnesium alloy ingots with a thickness of 300 mm.

[0097]

[0098] (2) Sawing and milling: Sawing and milling the aluminum-magnesium alloy ingot to obtain a milled aluminum-magnesium alloy ingot;

[0099] (3) Heating: The milled aluminum-magnesium alloy ingot is sent into a heating furnace and kept at 500°C for 6 hours to obtain a heat-treated aluminum-magnesium alloy ingot.

[0100] (4) Hot rolling: The aluminum alloy ingot that has undergone heat treatment is hot rolled to 4.0 mm. The final hot rolling temperature is 280°C to obtain hot rolled coil.

[0101] (5) Cold rolling: The hot-rolled coil is cold-rolled, and the mechanical crown of the rolls used is 0.12 mm, the roll profile curve is sin70°, and the pass processing rate is 27%; the crown of the strip after rolling is 0.01%; the total cold rolling processing rate is ≥70%; and a cold-rolled coil is obtained.

[0102] (6) Cleaning, annealing, and tension straightening: The cold-rolled coil is cleaned, annealed, and tension straightened in sequence; the annealing temperature is 250℃ and the annealing holding time is 3 hours; the cleaned and annealed coil is tension straightened and the finished coil diameter is ≤1350mm.

[0103]

[0104] As can be seen from the data in the table above, the method in this embodiment cannot solve the problem of white spot defects on the surface of the produced product.

[0105] The experimental results from the above embodiments show that the production method of aluminum-magnesium alloy cold-rolled coil of the present invention focuses on optimizing the cold rolling step and the tension leveling step. In the cold rolling step, the mechanical crown of the rolls is 0.10–0.15 mm, the roll profile curve is sin70–75°, and the pass processing rate is 25–30%. The crown of the strip after rolling is 0–0.02%. Controlling the crown of the cold-rolled strip effectively avoids excessive crown, which can lead to excessive tightness in the center of the finished coil after winding, making it prone to interlayer misalignment and white spot defects during transportation. In the tension leveling step, cleaning oil with a flash point of 40–60°C is sprayed at the tension leveler's coil shaft at a spraying rate of 1.0–2.0 g / m. 2 Finished coil diameter ≤ 1350mm; Surface spraying with cleaning oil provides interlayer protection and prevents interlayer misalignment; Using a flash point of 40~60℃ and controlling the amount of oil sprayed ensures effective protection of the strip while allowing the oil to evaporate before customer use, without affecting subsequent use; Controlling the finished coil diameter reduces shaking during aluminum coil transportation and prevents interlayer misalignment; Through simultaneous optimization of the cold rolling and tension leveling steps, the white spot defect on the surface of the produced product is effectively solved, meeting the surface quality requirements of end users. The process is simple, with low production and processing costs, effectively enhancing the product's market competitiveness.

[0106] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A method for producing cold-rolled aluminum-magnesium alloy coils, the process flow of which is: melting - casting - sawing - milling - heating - hot rolling - cold rolling - cleaning - annealing - tension leveling; characterized in that, In the smelting step, the mass percentage of the aluminum-magnesium alloy chemical composition is as follows: Si≤0.20%, Fe≤0.30%, Cu≤0.10%, Mn 0.05~0.10%, Mg 2.70~2.80%, Cr 0.15~0.20%, Zn≤0.10%, Ti 0.01~0.05%, other impurity elements ≤0.05% individually, other impurity elements ≤0.15% in total, and the remainder is Al; The cold rolling process is as follows: the mechanical crown of the rolls used is 0.10-0.15 mm, the roll profile curve is sin70-75°, and the pass processing rate is 25-30%; the crown of the strip after rolling is 0-0.02%; the total cold rolling processing rate is ≥70%. The tension straightening process is as follows: the cleaned and annealed roll material is subjected to tension straightening production; cleaning oil with a flash point of 40-60℃ is sprayed at the roll shaft of the tension straightening machine, and the oil spraying amount is 1.0-2.0 g / m. 2 Finished roll diameter ≤ 1350mm.

2. The method for producing cold-rolled aluminum-magnesium alloy coils according to claim 1, characterized in that, The cold rolling process is as follows: the mechanical crown of the rolls used is 0.12-0.15 mm, the roll profile is sin70-75°, and the pass processing rate is 27-30%; the crown of the strip after rolling is 0.01-0.02%.

3. The method for producing cold-rolled aluminum-magnesium alloy coils according to claim 1, characterized in that, The tension straightening process is as follows: the cleaned and annealed roll material is subjected to tension straightening production; cleaning oil with a flash point of 50-60℃ is sprayed at the roll shaft of the tension straightening machine, and the oil spraying amount is 1.5-2.0 g / m. 2 Finished roll diameter ≤ 1350mm.

4. The method for producing cold-rolled aluminum-magnesium alloy coils according to claim 1, characterized in that, In the hot rolling step, the final hot rolling temperature is 270–300°C.

5. The method for producing cold-rolled aluminum-magnesium alloy coils according to claim 1, characterized in that, In the hot rolling step, the aluminum-magnesium alloy ingot is hot rolled to 3.0-5.0 mm.

6. The method for producing cold-rolled aluminum-magnesium alloy coils according to claim 1, characterized in that, In the annealing step, the annealing temperature is 240-260℃, and the annealing holding time is 2-4 hours.

7. The method for producing cold-rolled aluminum-magnesium alloy coils according to claim 1, characterized in that, The heating temperature in the heating step is 480–510°C.

8. The method for producing cold-rolled aluminum-magnesium alloy coils according to claim 7, characterized in that, The heating and heat preservation time for the heating step is 2 to 8 hours.

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