A method for producing high-strength 8006 alloy container foil in a low-carbon and environmentally friendly manner

Abstract

This invention belongs to the field of aluminum alloy production technology, specifically disclosing a low-carbon and environmentally friendly method for producing high-strength 8006 alloy container foil. It optimizes the aluminum alloy composition ratio, melt treatment, and cold rolling process, enabling the large-scale utilization of recycled aluminum waste. Energy consumption is more than 50% lower than that of primary aluminum ingots. A 1.5mm thick billet is produced through three consecutive rolling mills, followed by 4-5 passes of cold foil rolling to produce the finished container foil. This reduces the number of rolling passes by 2-3 compared to conventional methods, saving processing costs of 500 yuan / ton. This production method can reduce the thickness of the billet and the number of cold foil rolling passes. High-temperature intermediate annealing is not required in the cold rolling process, saving approximately 280 kWh of annealing electricity per ton. This achieves low-carbon, short-process production. The finished product of this invention has a tensile strength ≥150 MPa and an elongation ≥18%, which is about 20 MPa higher than that of container foil produced by conventional methods. It is also less prone to deformation after stamping, resulting in better end-use performance.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of aluminum alloy production, and specifically discloses a low-carbon and environment-friendly method for producing high-strength 8006 alloy container foil. BACKGROUND

[0002] With the continuous promotion of the national plastic limit order and the increasing concern of people for food hygiene and safety issues, as a green packaging material, aluminum foil meal boxes are becoming the best choice for the catering industry and the food packaging industry. However, due to the high price of aluminum, the cost pressure faced by the use of aluminum foil meal boxes is also increasing. Thinning of aluminum foil meal boxes becomes the best solution to reduce costs, but thinning means that the meal boxes are weaker in deformation resistance and the use experience will be worse. The container foils on the market are mainly hot-rolled 3004 alloy and cast-rolled 3003, 8011 and 8006 alloy. Among them, the hot-rolled 3004 alloy container foil has a high production cost, and the cast-rolled 3003, 8011 and 8006 alloy container foils have low strength.

[0003] Under this background, manufacturing meal boxes that are thinner and more resistant to deformation becomes a good solution. Chinese patent CN116426794B uses continuous casting and rolling to produce 8006 alloy container foil, and the thickness of the produced container foil is 0.125-0.16mm, and the tensile strength is 110-140MPa. This scheme needs to perform high-temperature annealing once in the production of container foil, and the finished product is thick and has soft mechanical properties, which cannot meet the demand for manufacturing meal boxes that are thinner and more resistant to deformation, and is not conducive to market promotion and use. SUMMARY

[0004] To overcome the shortcomings of the prior art, the application discloses a low-carbon and environment-friendly method for producing high-strength 8006 alloy container foil, which uses continuous casting to produce 8006 alloy cast blanks, produces 1.5mm-thick blanks through three-continuous rolling, and produces high-strength container foil finished products through a new process flow different from the traditional process in the cold-foil rolling process, thereby reducing the thickness of the blanks, optimizing the cold rolling production process, reducing the cold-foil rolling production passes, and eliminating the need for high-temperature intermediate annealing, so that low-carbon short-flow production is realized.

[0005] To achieve the above-mentioned application purposes, the application adopts the following technical solutions:

[0006] A low-carbon and environment-friendly method for producing high-strength 8006 alloy container foil includes the following steps:

[0007] S1, smelting: 75%~85% recycled aluminum scrap and 15%~25% electrolytic aluminum liquid are put into a smelting furnace to prepare an aluminum melt, and after melting, the original sample is analyzed, and according to the analysis value, iron agent, titanium agent and manganese agent are added to adjust the alloy composition to be qualified, wherein the mass percentage of each component is: Si: ≤0.3%, Fe: 1.3-1.6%, Cu: ≤0.02%, Mn: 0.3-1.0%, Mg ≤0.02%, Zn ≤0.02%, Ti: 0.02%-0.03%, the total of impurity elements ≤0.03%, and the balance is aluminum, after adding the iron agent, fast-acting silicon and titanium agent, the melt is fully stirred, primary refining and local stirring are carried out by using a refiner, after primary refining, sampling and analysis are carried out, and after the composition is qualified, secondary refining is carried out, only argon gas is introduced as a refining gas during secondary refining, the melt is statically placed for 10 min after secondary refining, slagging is carried out, and the furnace is lifted after slagging for 30~40 min, and the lifting temperature is 715~725℃;

[0008] S2, online treatment of the melt: after the furnace is lifted, the aluminum melt flows smoothly into a flow guide chute, aluminum titanium boron wires are uniformly added into the aluminum melt to purify the aluminum melt, and after purification, the aluminum melt sequentially enters a degassing tank and a plate filter tank for degassing and filtering, and the aluminum melt directly flows into a forehearth after degassing and filtering;

[0009] S3, continuous casting: the temperature of the forehearth is 685℃~695℃, the aluminum melt in the forehearth flows into a casting cavity of a casting machine through a nozzle, the aluminum melt solidifies in the casting cavity to form a cast blank and then the cast blank is discharged as a plate, the casting speed is 7.2~8.0m / min, and the thickness of the cast blank is 19mm;

[0010] S4, continuous rolling: the cast blank enters a three-stand tandem rolling mill, the thickness of the plate blank at the outlet of the first stand of the three-stand tandem rolling mill is 7.0~8.0mm, the thickness of the plate blank at the outlet of the second stand of the three-stand tandem rolling mill is 3.0~4.0mm, the thickness of the plate blank at the outlet of the third stand of the three-stand tandem rolling mill is 1.5~2.0mm, and the plate blank at the outlet of the third stand of the three-stand tandem rolling mill is coiled;

[0011] S5, cold foil rolling: the 1.5-2.0mm thick aluminum coil directly enters a cold rolling mill train for 3-pass rolling, the rolling reduction of each cold rolling pass is 45%~55%, and after the cold rolling strip is trimmed, the cold rolling strip is prepared into an aluminum foil product by 1~2-pass cold rolling at a rolling reduction of 50%~55%;

[0012] S6, product annealing: the product aluminum foil coil is placed in an annealing furnace for product annealing, the temperature is uniformly raised to 200℃ within 2 hours, negative pressure holding is carried out for 4 hours, then the temperature is uniformly raised to 295℃ within 2 hours, positive pressure holding is carried out for 25-35 hours, then the furnace temperature is lowered to 170℃, the coil is discharged and naturally cooled to room temperature, the tensile strength of the aluminum foil product is 140MPa~60MPa, and the elongation is ≥18%.

[0013] Further, in the low-carbon and environmentally-friendly method for producing high-strength 8006 alloy container foil, in step S1, the recycled aluminum scrap is first added, and then the electrolytic aluminum liquid is added, and the electrolytic aluminum liquid can promote the melting of the recycled aluminum scrap, and the flow of the aluminum liquid can also play a role in uniform composition.

[0014] Further, in the low-carbon and environmentally-friendly method for producing high-strength 8006 alloy container foil, in step S1, the primary refining and secondary refining time is 30-40 min, the refining machine graphite rotor speed is set to 500-600 r / min, and the secondary refining gas pressure is 0.4-0.6 MPa.

[0015] Further, in the low-carbon and environmentally-friendly method for producing high-strength 8006 alloy container foil, in step S2, the argon gas is introduced into the degassing tank for online degassing, the three-rotor degassing is used in the degassing tank to ensure the degassing effect, the speed of the rotor of the degassing tank is 450-550 r / min, the rotor is immersed in the aluminum liquid at a height of more than 80 cm, and the furnace gas temperature of the plate filter tank is 735-745 DEG C.

[0016] Further, in the low-carbon and environmentally-friendly method for producing high-strength 8006 alloy container foil, in step S2, the aluminum-titanium-boron wire is added at a uniform speed of 3.0±1 m / min.

[0017] Further, in the low-carbon and environmentally-friendly method for producing high-strength 8006 alloy container foil, in step S4, the temperature of the aluminum strip metal plate at the outlet of the third rack of the three-stand rolling mill is 200-230 DEG C.

[0018] Further, in the low-carbon and environmentally-friendly method for producing high-strength 8006 alloy container foil, in step S4, the three racks of the three-stand rolling mill need to be cooled and lubricated using emulsion, and the emulsion concentration is 3.5±0.1%.

[0019] Further, in the low-carbon and environmentally-friendly method for producing high-strength 8006 alloy container foil, in step S5, the edge quality is strictly controlled during edge cutting, and problems such as layering, tower-shaped edge defects, etc. are not allowed.

[0020] Further, in the low-carbon and environmentally-friendly method for producing high-strength 8006 alloy container foil, in step S6, the temperature difference between the metal in each heating zone of the annealing furnace during annealing of the finished product is ≤2 DEG C.

[0021] Due to the adoption of the above technical solutions, the present application has the following advantages:

[0022] The application discloses a low-carbon and environment-friendly production method of high-strength 8006 alloy container foil, and relates to the technical field of aluminum alloy production. DETAILED DESCRIPTION

[0023] The application is further explained in connection with the embodiments below, which cannot limit the protection scope of the application, and the purpose of the application is to protect all technical improvements within the scope of the application. Embodiment 1

[0024] A low-carbon and environment-friendly production method of high-strength 8006 alloy container foil, and relates to the technical field of aluminum alloy production.

[0025] S1, melting: 76.6% of recycled aluminum scrap, 23.4% of electrolytic aluminum liquid are sequentially put into a smelting furnace to prepare an aluminum melt, the single furnace loading capacity is 108.2t, after melting, the original sample is taken for analysis, according to the analysis value, iron agent, titanium agent and manganese agent are added to adjust the alloy composition to be qualified, wherein the mass percentage of each component is: Si: 0.21%, Fe: 1.36%, Cu: 0.012%, Mn: 0.68%, Mg: 0.017%, Zn: 0.018%, Ti: 0.023%, the total of impurity elements is less than or equal to 0.03%, and the balance is aluminum, after adding the iron agent, the quick-dissolved silicon and the titanium agent, the electromagnetic stirring is turned on to ensure that the melt is fully stirred, so as to avoid the enrichment and segregation of the alloy composition; an HD2000 refiner is used for primary refining and local stirring, the primary refining time is 32min, the rotating speed of the graphite rotor matched with the HD2000 refiner is 520r / min, after primary refining, the sample is taken for analysis, after the composition is qualified, secondary refining is carried out, only argon gas is used as the refining gas in the secondary refining, the gas pressure is 0.45MPa, the refining time is 310min, after refining, the aluminum melt is statically placed for 10min, a slag skimming vehicle is used for slag skimming operation, so that the floating slag with an area of more than 20mm*20mm on the surface of the aluminum melt is completely removed, after slag skimming, the furnace is produced after being statically placed for 32min, and the furnace temperature is 718℃;

[0026] S2, melt online processing: after the furnace, the aluminum melt flows into the flow tank, according to the 3.0±1m / min adding speed to the aluminum melt uniform speed adding two groups of aluminum titanium boron wire; The aluminum melt added with aluminum titanium boron wire flows into the degassing tank, and argon is introduced into the degassing tank for online degassing. The degassing tank adopts three rotor degassing to ensure the degassing effect. The rotating speed of the rotor of the degassing tank is 450r / min. The rotor is immersed in the aluminum liquid above 80cm height. After degassing, the aluminum melt enters the plate filter tank for filtration. The plate filter tank needs to be heated and kept warm. The furnace gas temperature in the plate filter tank is 738℃. The aluminum melt filtered by degassing flows directly into the front tank;

[0027] S3, continuous casting: the temperature of the front tank is set to 688℃ during continuous casting. The aluminum melt in the front tank flows into the casting cavity of the casting machine through the casting nozzle. The casting cavity is composed of upper and lower steel belts and side blocks. The aluminum melt solidifies in the casting cavity to form a casting blank. The heat of the aluminum melt can be transferred to the cooling water through the steel belt. With the same direction rotation of the upper and lower steel belts, the heat of the stable aluminum melt is taken away by the cooling water to form a casting blank and then out of the plate. The casting speed is 7.3m / min, and the thickness of the casting blank is 19mm.

[0028] S4, continuous rolling: the casting blank enters the three continuous rolling mill through the rolling mill rack pinch roll. The thickness of the plate blank at the outlet of the first rack of the three continuous rolling mill is 7.8mm. The thickness of the plate blank at the outlet of the second rack of the three continuous rolling mill is 3.8mm. The thickness of the plate blank at the outlet of the third rack of the three continuous rolling mill is 1.8mm. Emulsion is used for cooling and lubrication during three continuous rolling. The emulsion concentration is 3.55%. The plate blank at the outlet of the third rack of the three continuous rolling mill is coiled. The temperature of the plate blank at the outlet of the third rack of the three continuous rolling mill is 221℃.

[0029] S5, cold foil rolling: the 1.8mm thick aluminum coil is directly fed into the cold rolling mill group for 3 passes. The processing rate of each cold rolling pass is controlled at about 55%. The 0.17mm thick cold rolled strip after rolling is arranged on the slitting machine for edge trimming. The single edge trimming amount is 20-30mm. The edge quality is strictly controlled during edge trimming. No problems such as layering, tower-shaped edge defects are allowed. The cold rolled coil after edge trimming is rolled to a thickness of 0.082mm in one pass with a processing rate of 52%.

[0030] S6, finished product annealing: the finished aluminum foil coil is placed in the annealing furnace for finished product annealing. The temperature difference between each heating zone of the annealing furnace is ≤2℃. The temperature is uniformly raised to 200℃ for 4 hours under negative pressure. Then the temperature is uniformly raised to 295℃ for 32 hours under positive pressure. Then the furnace temperature is reduced to 170℃ and the product is taken out and naturally cooled to room temperature. The thickness and width of the aluminum foil after annealing should not exceed the required range. The surface quality should not have defects such as butter spots, roll marks and scratches. The end face quality should not have defects such as burrs, flanging and bruising. The tensile strength of the aluminum foil product is 156MPa, and the elongation is 23%. The final product is packaged according to the packaging requirements of the container aluminum foil. Example 2

[0031] A method for producing high-strength 8006 alloy container foil with low carbon and environmental protection, the specific steps are:

[0032] S1, smelting: 84.3% recycled aluminum scrap, 15.7% electrolytic aluminum liquid are sequentially put into a smelting furnace to prepare an aluminum melt, the single furnace loading capacity is 109.3t, after melting, the original sample is taken for analysis, according to the analysis value, iron agent, titanium agent and manganese agent are added to adjust the alloy composition to be qualified, wherein the mass percentage of each component is: Si: 0.18%, Fe: 1.42%, Cu: 0.019%, Mn: 0.78%, Mg: 0.018%, Zn: 0.011%, Ti: 0.026%, the total of impurity elements is ≤0.03%, and the balance is aluminum. After adding the iron agent, the fast-dissolved silicon and the titanium agent, the electromagnetic stirring is turned on to ensure that the melt is stirred fully to avoid the enrichment and segregation of the alloy composition; the HD2000 refiner is used for primary refining and local stirring, the primary refining time is set to 39min, the rotating speed of the graphite rotor matched with the HD2000 is set to 550r / min, the composition is analyzed after primary refining, and the secondary refining is carried out after the composition is qualified, only argon gas is introduced as the refining gas for the secondary refining, the gas pressure is 0.52MPa, the secondary refining time is 39min, the secondary refining is statically placed for 10min, the slag removal operation is carried out using a slag removal vehicle to ensure that the floating slag with a surface area of more than 20mm*20mm is removed completely, and the production is started after the slag removal for 38min, and the starting temperature is 723℃;

[0033] S2, online treatment of the melt: after the furnace is started, the aluminum melt flows into the flow guide chute smoothly, two groups of aluminum titanium boron wires are added into the aluminum melt at a uniform speed according to the adding speed of 3.0±1m / min; the aluminum melt added with the aluminum titanium boron wires flows into the degassing box, argon gas is introduced into the degassing box for online degassing, the degassing box adopts three rotors for degassing, the rotating speed of the rotors of the degassing box is 550r / min, the rotors are immersed in the aluminum liquid above 80cm to ensure the degassing effect, and after degassing, the aluminum melt enters the plate filter box for filtration, the plate filter box needs to be heated and kept warm, the furnace gas temperature in the plate filter box is 742℃, and the aluminum melt after degassing and filtration directly flows into the front box;

[0034] S3, continuous casting: the temperature of the front box is set to 694℃ during continuous casting, the aluminum melt in the front box flows into the casting cavity of the casting machine through the nozzle, the casting cavity is composed of upper and lower steel belts and edge blocks, the aluminum melt solidifies to form a casting blank in the casting cavity, the heat of the aluminum melt can be transferred to the cooling water through the steel belts, with the same direction rotation of the upper and lower steel belts, the heat of the stably supplied aluminum melt is taken away by the cooling water to form a casting blank and then out of the plate, the casting speed is 7.8m / min, and the thickness of the casting blank is 19mm;

[0035] S4, continuous rolling: the cast blank enters the three continuous rolling mill through the roller of the rolling mill stand, the slab outlet thickness of the first mill stand of the three continuous rolling mill is 7.2 mm, the slab outlet thickness of the second mill stand of the three continuous rolling mill is 3.3 mm, the slab outlet thickness of the third mill stand of the three continuous rolling mill is 1.6 mm, emulsion needs to be used for cooling and lubrication during the three continuous rolling, the emulsion concentration is 3.48%, and the slab at the outlet of the third mill stand of the three continuous rolling mill is coiled; the slab temperature at the outlet of the third mill stand of the three continuous rolling mill is 212℃;

[0036] S5, cold foil rolling: the 1.6 mm thick aluminum coil is directly rolled on the cold rolling mill group for 3 passes, the processing rate of each cold rolling pass is controlled at about 52%, the 0.18 mm thick cold rolling strip after rolling is arranged to cut the edge on the slitting machine, the single edge cutting amount is 20-30 mm, the edge quality is strictly controlled during cutting, and problems such as layering, tower-shaped cutting defects are not allowed; the cold rolling coil after cutting is rolled for 2 passes to 0.045 mm thickness with a processing rate of 50%;

[0037] S6, product annealing: the product aluminum foil coil is placed in the annealing furnace for product annealing, the temperature difference between each heating zone of the annealing furnace is ≤2℃, the temperature is raised to 200℃ for 2 hours, and then the temperature is raised to 295℃ for 28 hours under positive pressure, then the furnace temperature is reduced to 170℃, and the coil is taken out and naturally cooled to room temperature, the aluminum foil thickness and width after annealing need to be checked and cannot exceed the required range, the surface quality needs to be checked and cannot have defects such as butter stains, roll marks and scratches, the end face quality needs to be checked and cannot have defects such as burrs, flanging and bruising, the tensile strength of the aluminum foil product is 159 MPa, the elongation is 18%, and finally the aluminum foil product is packaged according to the packaging requirements of the container aluminum foil.

[0038] The part of the application not described in detail is the prior art.

[0039] The examples selected in the present text in order to disclose the inventive purpose of the present application are currently considered appropriate, but it should be understood that the present application is intended to include all the variations and improvements of the examples that fall within the scope of the present concept and invention.

Claims

1. A method for low carbon, environmentally friendly production of high strength 8006 alloy can foil, characterized by, It comprises the following steps: S1, smelting: put 75%-85% recycled aluminum scrap and 15%-25% electrolytic aluminum liquid into a smelting furnace to prepare an aluminum melt, take a sample for analysis after melting, and add iron agent, titanium agent and manganese agent to adjust the alloy composition to be qualified, wherein the mass percentage of each component is: Si: ≤0.3%, Fe: 1.3-1.6%, Cu: ≤0.02%, Mn: 0.3-1.0%, Mg ≤0.02%, Zn ≤0.02%, Ti: 0.02%-0.03%, the total of impurity elements ≤0.03%, and the balance is aluminum, after adding the iron agent, fast-dissolving silicon and titanium agent, ensure that the melt is fully stirred, use a refiner to perform primary refining, take a sample for analysis after primary refining, and perform secondary refining after the composition is qualified, only argon gas is used as the refining gas for secondary refining, the melt is placed for 10 minutes after secondary refining, slagging operation is performed, and the furnace is raised after slagging for 30-40 minutes, the furnace raising temperature is 715-725℃; S2, online melt treatment: after the furnace is raised, the aluminum melt flows smoothly into a flow guide chute, aluminum titanium boron wire is uniformly added into the aluminum melt to purify the aluminum melt, and the purified aluminum melt enters a degassing tank and a plate filter tank in sequence for degassing and filtering, and the aluminum melt directly flows into a forehearth after degassing and filtering; S3, continuous casting: the temperature of the forehearth is 685℃-695℃, the aluminum melt in the forehearth flows into a casting nozzle and then into a casting cavity of a casting machine, the aluminum melt solidifies in the casting cavity to form a cast slab and then is discharged as a plate, the casting speed is 7.2-8.0m / min, and the thickness of the cast slab is 19mm; S4, continuous rolling: the cast slab enters a three-stand tandem rolling mill, the thickness of the plate slab at the outlet of the first stand of the three-stand tandem rolling mill is 7.0-8.0mm, the thickness of the plate slab at the outlet of the second stand of the three-stand tandem rolling mill is 3.0-4.0mm, the thickness of the plate slab at the outlet of the third stand of the three-stand tandem rolling mill is 1.5-2.0mm, and the plate slab at the outlet of the third stand of the three-stand tandem rolling mill is coiled; S5, cold foil rolling: the 1.5-2.0mm thick aluminum coil is directly fed into a cold rolling mill train for 3-pass rolling, the rolling reduction of each cold rolling pass is 45%-55%, and the cold rolled strip after edge cutting is cold rolled for 1-2 passes at a rolling reduction of 50%-55% to prepare an aluminum foil product; S6, product annealing: the product aluminum foil coil is placed in an annealing furnace for product annealing, the temperature is uniformly raised to 200℃ within 2 hours, the temperature is kept at 200℃ under negative pressure for 4 hours, then the temperature is uniformly raised to 295℃ within 2 hours, the temperature is kept at 295℃ under positive pressure for 25-35 hours, then the furnace temperature is lowered to 170℃, the coil is discharged and naturally cooled to room temperature, and the tensile strength of the aluminum foil product is 140Mpa-60Mpa and the elongation is ≥18%.

2. The method of low carbon, environmentally friendly production of high strength 8006 alloy container foil according to claim 1, characterized in that, In step S1, the recycled aluminum scrap is added first, and then the electrolytic aluminum liquid is added.

3. The method of low carbon, environmentally friendly production of high strength 8006 alloy container foil according to claim 1, characterized in that, In step S1, the primary refining and secondary refining times are 30-40 minutes respectively, the graphite rotor speed of the refiner is set to 500-600r / min, and the secondary refining gas pressure is 0.4-0.6MPa.

4. The method of low carbon, environmentally friendly production of high strength 8006 alloy container foil according to claim 1, characterized in that, In step S2, the rotor speed of the degassing tank is 450-550r / min, the rotor is immersed in the aluminum liquid by more than 80cm, and the plate filter tank furnace gas temperature is 735℃-745℃.

5. The method of low carbon, environmentally friendly production of high strength 8006 alloy container foil according to claim 1, characterized in that, In step S2, the aluminum titanium boron wire is added at a uniform speed of 3.0±1 m / min.

6. The method of low carbon, environmentally friendly production of high strength 8006 alloy container foil according to claim 1, characterized in that, In step S4, the temperature of the aluminum strip metal plate at the outlet of the third stand of the three-stand rolling mill is 200-230℃.

7. The method of low carbon, environmentally friendly production of high strength 8006 alloy container foil according to claim 1, characterized in that, In step S4, emulsion is used for cooling and lubrication of the three stands of the three-stand rolling mill, and the concentration of the emulsion is 3.5±0.1%.

8. The method of low carbon, environmentally friendly production of high strength 8006 alloy container foil according to claim 1, characterized in that, In step S5, the edge quality is strictly controlled during trimming, and problems such as layering and tower-shaped bad trimming are not allowed.

9. The method of low carbon, environmentally friendly production of high strength 8006 alloy container foil according to claim 1, characterized in that, In step S6, the temperature difference between the heating zones of the annealing furnace is ≤2℃ during annealing of the finished product.