A 5657 aluminum alloy sheet for cosmetic container caps and its preparation method

Abstract

This invention discloses a 5657 aluminum alloy sheet for cosmetic container caps and its preparation method. The alloy chemical composition of the 5657 aluminum alloy sheet is Si 0-0.075%, Fe 0-0.09%, Cu 0.04-0.08%, Mn 0-0.02%, Mg 0.65-0.8%, Cr 0-0.02%, Zn 0-0.03%, and Ti 0.015-0.025%, with the balance being Al and unavoidable impurities. Using pure aluminum ingots as raw material, the process involves smelting, refining, casting, milling, homogenization heat treatment, hot rough rolling, hot finish rolling, cold rolling, intermediate annealing, cold rolling, surface alkaline washing, and slitting and packaging to obtain the 5657 aluminum alloy sheet for cosmetic container caps. The product of this invention has excellent mechanical properties, low ear-making rate, and high gloss and good coloring ability after anodizing, which can fully meet the market requirements for aluminum alloy thin sheets in this application field.

Description

I. Technical Field:

[0001] This invention relates to the field of aluminum alloy manufacturing technology, and in particular to a 5657 aluminum alloy sheet for cosmetic container caps and its preparation method. II. Background Technology:

[0002] Aluminum and aluminum alloys are widely used in various aspects of life due to their high strength, tensile forming properties, and excellent physical and chemical properties. Aluminum alloy sheets for cosmetic container caps, after processes such as stamping, stretching, mechanical grinding, electrolytic polishing, and anodizing, can achieve a certain level of brightness and possess characteristics such as good color, metallic appearance, and strong stain resistance, making aluminum alloy sheets a suitable raw material for downstream production of cosmetic container caps.

[0003] The downstream process for traditional cosmetic container caps includes stamping, ear trimming, mechanical polishing, electrolytic polishing, anodizing, oxidation coloring, sealing, and drying. Currently, the mechanical polishing depth is 20-30μm, which generates a large amount of metal dust, causing significant harm to the health of production operators and the environment. If mechanical polishing is not used or the polishing degree is insufficient, the gloss level after electrolytic polishing will not meet the requirements, thus failing to satisfy the usage requirements of high-end cosmetic container caps.

[0004] Meanwhile, the chemical composition, microstructure uniformity, anisotropy, and manufacturing process of the aluminum alloy substrate all affect the final polishing and anodizing effect of the product. For example, traditional cosmetic container caps made of 1060 / 1070 / 1080 aluminum alloy sheets suffer from a combination of problems, including low aluminum substrate strength, low gloss after anodizing, poor coloring ability, poor anisotropy, unstable performance, and unstable surface, which seriously restricts the use and promotion of aluminum alloys in the field of high-end cosmetic container caps.

[0005] With the development of the high-end cosmetic container cap market, the requirements for raw materials are becoming increasingly stringent, creating an urgent need for a new material to meet the demands of high-end cosmetic container caps. The advantages of 5657 aluminum alloy sheet for cosmetic container caps are evident: the surface is free of visible defects such as material marks, black streaks, and color differences; it has good deep-drawing and stretching formability; a low ear-making rate; and after anodizing, it exhibits high gloss and uniform color, fully meeting the requirements of the high-end cosmetic container cap market for aluminum alloy sheet. III. Summary of the Invention:

[0006] The technical problem this invention aims to solve is: based on the requirements of high-end cosmetic technology for aluminum alloy sheet used in container caps, this invention provides a 5657 aluminum alloy sheet for cosmetic container caps and its preparation method. The 5657 aluminum alloy sheet product for cosmetic container caps prepared using this invention exhibits excellent mechanical properties, low ear-forming rate, and high gloss and good coloring ability after anodizing. Therefore, in this application field, the product prepared by this invention fully meets the requirements of the high-end cosmetic container cap market for aluminum alloy sheet.

[0007] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0008] This invention provides a 5657 aluminum alloy sheet for cosmetic container caps. The alloy chemical composition of the 5657 aluminum alloy sheet for cosmetic container caps, expressed as a percentage by mass, is: Si 0-0.075%, Fe 0-0.09%, Cu 0.04-0.08%, Mn 0-0.02%, Mg 0.65-0.8%, Cr 0-0.02%, Zn 0-0.03%, and Ti 0.015-0.025%, with the balance being Al and unavoidable impurities.

[0009] In addition, a method for preparing a 5657 aluminum alloy sheet for cosmetic container caps is provided, the method comprising the following steps:

[0010] 1) Smelting: Pure aluminum ingots are added to a flame reverberatory furnace for heating and smelting. The smelting temperature in the furnace is controlled at 720-760℃. After all the raw materials in the furnace have melted, the slag is removed by stirring to obtain the original alloy liquid. Then, 100% pure magnesium ingots, AL-75Cr, AL-75Cu and AL-5Ti-B are added to the original alloy liquid for batching at a temperature of 725-740℃. After batching, the alloy chemical composition of the alloy liquid obtained by smelting meets the above-mentioned alloy element chemical composition of 5657 aluminum alloy sheet blank for cosmetic container caps.

[0011] 2) Refining: The alloy liquid obtained after batching in step 1) is refined. The furnace induction time is 40-60 minutes. After the furnace induction is completed, the refining is carried out by mixing gas with environmentally friendly solid particle refining agent. The refining temperature is controlled at 725-740℃ and the refining time is 40-120 minutes. After the refining is completed, the slag is removed and the mixture is allowed to stand for 20-50 minutes.

[0012] 3) Casting: The aluminum alloy liquid obtained after refining in step 2) is subjected to online primary plate filtration, online degassing, secondary plate filtration and tubular filtration in sequence. The alloy liquid obtained after filtration is cast into aluminum alloy flat ingots.

[0013] 4) Sawing and milling: The aluminum alloy flat ingot obtained in step 3) is first sawed, with a saw head of 300-500mm and a saw tail of 100-200mm; then the surface is milled, with a single-sided milling amount of 15-25mm on the large surface and 5-10mm on the small surface (to ensure that the surface is free of obvious defects such as pores, slag inclusions, unmilled areas, cold shuts, cracks, dents, oil stains, etc.), and a clean ingot is obtained after milling.

[0014] 5) Homogenization heat treatment: The cleaned ingots obtained in step 4) are placed in a heating furnace for homogenization heat treatment;

[0015] 6) Hot rough rolling: The slab obtained after heat treatment in step 5) is rolled into an intermediate plate with a thickness of 33-37 mm by 19-23 passes of rough rolling. The entry temperature of the rough rolling is 480-510℃.

[0016] 7) Hot finishing rolling: The hot-rolled intermediate plate obtained in step 6) is rolled into a hot-rolled billet coil with a thickness of 7.0 mm through 4 passes of hot continuous rolling. The finishing rolling inlet temperature is 390~410℃ and the finishing rolling temperature is 285~300℃. After leaving the mill, it is allowed to cool down naturally.

[0017] 8) Cold rolling: The aluminum alloy billet obtained in step 7) is naturally cooled to ≤50℃, and then cold rolled to obtain a cold-rolled coil with an intermediate thickness of 2.0mm;

[0018] 9) Intermediate annealing: The intermediate thickness cold-rolled coil obtained in step 8) is subjected to intermediate annealing;

[0019] 10) Cold-rolled finished product: The intermediate thickness coil after intermediate annealing in step 9) is cooled to ≤40℃ by air cooling, and then cold-rolled to obtain a cold-rolled coil with a thickness of 0.4mm.

[0020] 11) Surface alkaline washing: The cold-rolled finished coil obtained in step 10) is subjected to surface alkaline washing treatment;

[0021] 12) Cutting and packaging: Cool the roll material obtained in step 11) to room temperature and then package the resulting sheet material horizontally.

[0022] According to the above-mentioned preparation method of 5657 aluminum alloy sheet for cosmetic container cap, expressed as a percentage by mass, the raw material pure aluminum ingot in step 1) consists of 65-70% aluminum ingot with a purity of 99.85% and 30-35% aluminum ingot with a purity of 99.90%.

[0023] According to the above-mentioned preparation method of 5657 aluminum alloy sheet for cosmetic container caps, the gas mentioned in step 2) is 100% pure argon, and the environmentally friendly solid particle refining agent is a sodium-free refining agent; during the refining process, the amount of sodium-free refining agent added to the furnace is 0.6-0.8 kg of sodium-free refining agent per 1000 kg of aluminum melt, so that the hydrogen content after refining in the static furnace is <0.20 ml / 100 g (Al), and the rotation speed of the degassing box rotor is 350-380 r / min; after refining, online degassing is performed to control the hydrogen content to ≤0.15 ml / 100 g (Al).

[0024] According to the above-mentioned method for preparing 5657 aluminum alloy sheet for cosmetic container caps, the primary and secondary plate filters in step 3) have a filter resolution of 40 ppi and 60 ppi, respectively. The casting temperature is 690–720℃, the casting speed is 46–48 mm / min, and the water flow rate is set to 50–70 m³ / min. 3 / piece, the length of the cast aluminum alloy flat ingot is 6200-6400mm. After casting, wait for the end of the ingot gate to cool fully, then turn off the water circulation cooling after 15 minutes, and then hoist it.

[0025] According to the above-mentioned preparation method of 5657 aluminum alloy sheet for cosmetic container caps, the specific process of homogenization heat treatment in step 5) is as follows: the heating process is carried out in stages, and the furnace gas temperature is set to 400℃-430℃-460℃-490℃-520℃ respectively. After each stage reaches the set furnace gas temperature target value, the temperature is held for 2 hours before starting the next stage. This continues until the final heating stage is completed. The heating time is 17-19 hours. The metal temperature is controlled at 485-505℃ and the holding time is 6-8 hours. The metal is then removed from the furnace.

[0026] According to the above-mentioned preparation method of 5657 aluminum alloy sheet for cosmetic container cap, in the cold rolling process described in step 8), the total rolling rate is 71%, the pass distribution is 7.0-3.8-2.0mm, the uncoiling tension is set to 40-45KN, the coiling tension is set to 60-100KN, and the rolling speed is 280-320m / min.

[0027] According to the above-mentioned preparation method of 5657 aluminum alloy sheet for cosmetic container cap, in the intermediate annealing process described in step 9), the furnace gas temperature is set to 240°C in the first stage, oil is blown for 2 hours, and nitrogen is used for protection; the furnace gas temperature is set to 380°C in the second stage, and the metal temperature is raised to 310°C; in the third stage, the furnace gas temperature is changed to 330°C, the temperature is held for 3 hours, and the metal is rapidly cooled by air after exiting the furnace.

[0028] According to the above-mentioned preparation method of 5657 aluminum alloy sheet for cosmetic container cap, in the cold rolling process described in step 10), the total rolling rate is 80%, the pass distribution is 2.0-1.3-0.8-0.58-0.4mm, the uncoiling tension is set to 22-45KN, the coiling tension is set to 20-55KN, and the rolling speed is 340-700m / min.

[0029] According to the above-mentioned preparation method of 5657 aluminum alloy sheet for cosmetic container cap, in the surface alkaline washing process described in step 11), the temperature is set to 60-75℃, the linear speed is set to 50-80m / min, and the alkaline concentration is set to 2%.

[0030] The positive and beneficial effects of this invention are:

[0031] 1. The 5657 aluminum alloy sheet product for cosmetic container caps prepared by the method of the present invention is achieved by strictly controlling the content of Si, Fe, Cu, and Mg and the Si / Fe ratio through chemical composition design, and by coordinating the process technology. The key processes include: (1) heat treatment to homogenize the billet and improve the microstructure segregation; (2) setting the final rolling temperature range to increase the proportion of re-forming texture after the hot-rolled billet is rolled off the line, thereby improving the anisotropy of the material; (3) increasing the thickness of the hot-rolled billet to 7.0 mm, increasing the total processing rate of the cold-rolled billet, increasing the driving force for microstructure recrystallization during intermediate annealing, improving the uniformity of grain size, and improving the processing performance of the finished product. Through the above process technology optimization and control, the 5657 aluminum alloy sheet product for cosmetic container caps prepared by the present invention has excellent mechanical properties and the ear-making rate is ≤5%, which can fully meet the requirements of the market for high-end cosmetic container caps for aluminum alloy sheet products.

[0032] 2. The 5657 aluminum alloy sheet product for cosmetic container caps prepared by the method of the present invention uses a mixed refining method of gas and environmentally friendly solid particle refining agent to purify the aluminum melt in the refining process of the preparation method. The refining medium is mainly environmentally friendly argon gas and environmentally friendly solid particle refining agent, which replaces the traditional chlorine-containing and sodium-containing refining agent, and meets the requirements of green development in the industry.

[0033] 3. The 5657 aluminum alloy sheet product for cosmetic container caps prepared using the method of this invention has high gloss and good coloring ability after anodizing. In this application field, the product prepared by this invention fully meets the requirements of the high-end cosmetic container cap market for aluminum alloy sheets, and can change the problem of traditional downstream processing requiring electrolytic polishing to increase brightness or resulting in insufficient brightness after electrolytic polishing. At the same time, it reduces manufacturing processes, lowers production costs, avoids the generation of large amounts of metal dust, improves the working environment, and has high market demand.

[0034] 4. The cosmetic container cap prepared using the technical solution of this invention was tested using a 5657 aluminum alloy sheet. The relevant performance parameters are detailed in Table 1.

[0035] Table 1 Performance testing data related to the product of this invention

[0036] IV. Detailed Implementation Methods:

[0037] The present invention will be further illustrated below with reference to the embodiments, but this does not limit the scope of protection of the technical solution of the present invention.

[0038] Example 1:

[0039] The cosmetic container cap of this invention is made of 5657 aluminum alloy sheet, expressed as a percentage by mass. Its alloy chemical composition is as follows: Si 0.030%, Fe 0.065%, Cu 0.048%, Mn 0.0021%, Mg 0.696%, Cr 0.0004%, Zn 0.0066%, and Ti 0.019%, with the balance being Al and unavoidable impurities.

[0040] Example 2:

[0041] The detailed steps of the preparation method of the 5657 aluminum alloy sheet for cosmetic container caps described in Embodiment 1 of the present invention are as follows:

[0042] 1) Smelting: The raw material, pure aluminum ingots, is added to a flame-reflective furnace for heating and smelting (the pure aluminum ingots consist of 70% aluminum ingots with a purity of 99.85% and 30% aluminum ingots with a purity of 99.90%). The smelting temperature in the furnace is controlled at 750℃. After all the raw materials in the furnace have melted, the slag is removed by stirring to obtain the original alloy liquid. Then, 100% pure magnesium ingots, Al-75Cr, Al-75Cu, and Al-5Ti-B are added to the obtained original alloy liquid for batching (Al-75... Cu refers to a 75% purity Al-Cu master alloy, in which Cu accounts for 75% by mass; Al-75Cr refers to a 75% purity Al-Cr master alloy, in which Cr accounts for 75% by mass. The batching temperature is 725℃, and the alloy chemical composition of the resulting molten alloy meets the alloy element composition of the 5657 aluminum alloy sheet blank for cosmetic container caps described in Example 1.

[0043] 2) Refining: The alloy liquid obtained after batching in step 1) is refined. The furnace induction time is 45 minutes. After the furnace induction is completed, 100% pure argon gas and sodium-free refining agent (environmentally friendly solid granular refining agent) are mixed to purify the aluminum melt. The amount of sodium-free refining agent added is 0.8 kg / 1000 kg of aluminum melt. After refining in the static furnace, the hydrogen content is controlled to be 0.17 ml / 100 g (Al). The rotor speed of the degassing box is 350 r / min. After degassing and purification, online degassing is performed, and the hydrogen content is controlled to be 0.121 ml / 100 g (Al). The refining temperature is controlled at 725℃ and the refining time is 40 minutes. After refining, slag is removed and the mixture is allowed to stand for 25 minutes.

[0044] 3) Casting: The aluminum alloy liquid obtained after refining in step 2) is subjected to online primary plate filtration, online degassing, secondary plate filtration and tubular filtration in sequence. The alloy liquid obtained after filtration is cast into aluminum alloy flat ingots.

[0045] The primary and secondary plate filters have a filter resolution of 40 ppi and 60 ppi, respectively. The casting temperature is 698℃, the casting speed is 46 mm / min, and the water flow rate is set to 55 m³ / min. 3 / piece, the length of the cast aluminum alloy flat ingot is 6300mm. After casting, wait for the end of the ingot gate to cool fully, then turn off the water circulation cooling after 15 minutes, and then hoist it.

[0046] 4) Sawing and milling: The aluminum alloy flat ingot obtained in step 3) is first sawed with a saw head of 300mm and a saw tail of 100mm; then it is milled, with a single-sided milling amount of 15mm on the large surface and 5mm on the small surface (to ensure that the surface is free of obvious defects such as pores, slag inclusions, unmilled areas, cold shuts, cracks, dents, oil stains, etc.). After milling, a clean ingot is obtained.

[0047] 5) Homogenization heat treatment: The cleaned ingots obtained in step 4) are placed in a heating furnace for homogenization heat treatment;

[0048] The specific process of the homogenization heat treatment is as follows: the heating process is carried out in stages, with the furnace gas temperature set at 400℃-430℃-460℃-490℃-520℃ respectively. After each stage reaches the set furnace gas temperature target value, the temperature is held for 2 hours before starting the next stage, until the final heating stage is completed. The heating time is 17 hours. At the beginning of the holding period, the metal temperature is controlled at 485℃ and the holding time is 8 hours, after which the metal is removed from the furnace.

[0049] 6) Hot rough rolling: The slab obtained after heat treatment in step 5) is rolled into an intermediate plate with a thickness of 34 mm through 23 passes of rough rolling. The entry temperature of the rough rolling is 490℃.

[0050] 7) Hot finishing rolling: The hot-rolled intermediate plate obtained in step 6) is rolled into a hot-rolled billet coil with a thickness of 7.0 mm through 4 passes of hot continuous rolling. The finishing rolling inlet temperature is 395℃ and the finishing rolling temperature is 286℃. After leaving the mill, it is allowed to cool down naturally.

[0051] 8) Cold rolling: The aluminum alloy billet obtained in step 7) is naturally cooled to 48°C and then cold rolled. The total rolling rate is 71%, the pass distribution is 7.0-3.8-2.0mm, the uncoiling tension is set to 40-45KN, the coiling tension is set to 60-100KN, and the rolling speed is 280-320m / min, to obtain a cold rolled coil with an intermediate thickness of 2.0mm.

[0052] 9) Intermediate annealing: The intermediate thickness cold-rolled coil obtained in step 8) is subjected to intermediate annealing. The furnace gas temperature is set to 240°C in the first stage, oil is blown for 2 hours, and nitrogen is used for protection. The furnace gas temperature is set to 380°C in the second stage, and the metal temperature is raised to 310°C. The furnace gas temperature is changed to 330°C in the third stage, and the temperature is held for 3 hours. After exiting the furnace, the metal is quickly cooled by air.

[0053] 10) Cold-rolled finished product: The intermediate thickness coil after intermediate annealing in step 9) is cooled to 40°C by air cooling, and then cold-rolled. The total rolling rate is 80%, the pass distribution is 2.0-1.3-0.8-0.58-0.4mm, the uncoiling tension setting range is 22~45KN, the coiling tension setting range is 20~55KN, and the stable rolling speed range is 340~700m / min. After cold rolling, a cold-rolled coil with a thickness of 0.4mm is obtained.

[0054] 11) Surface alkaline washing: The cold-rolled finished coil obtained in step 10) is subjected to surface alkaline washing treatment. The temperature is set to 60℃, the linear speed is set to 55m / min, and the alkaline concentration is set to 2%.

[0055] 12) Cutting and packaging: Cool the roll material obtained in step 11) to room temperature and then package the resulting sheet material horizontally.

[0056] The mechanical comparison data of the 5657 aluminum alloy sheet for cosmetic container caps prepared in Example 2 of this invention are detailed in Table 2.

[0057] Table 2. Performance test data of the product prepared in Example 2 of this invention.

[0058]

[0059] Example 3:

[0060] The cosmetic container cap of this invention is made of 5657 aluminum alloy sheet, expressed as a percentage by mass. Its alloy chemical composition is as follows: Si 0.035%, Fe 0.070%, Cu 0.047%, Mn 0.0022%, Mg 0.710%, Cr 0.0004%, Zn 0.0060%, and Ti 0.021%, with the balance being Al and unavoidable impurities.

[0061] Example 4:

[0062] The detailed steps of the preparation method of the 5657 aluminum alloy sheet for cosmetic container caps described in Embodiment 3 of the present invention are as follows:

[0063] 1) Smelting: The raw material, pure aluminum ingots, is added to a flame-reflective furnace for heating and smelting (the pure aluminum ingots consist of 68% aluminum ingots with a purity of 99.85% and 32% aluminum ingots with a purity of 99.90%). The smelting temperature in the furnace is controlled at 745℃. After all the raw materials in the furnace have melted, the slag is removed by stirring to obtain the original alloy liquid. Then, 100% pure magnesium ingots, Al-75Cr, Al-75Cu, and Al-5Ti-B are added to the obtained original alloy liquid for batching (Al-75... Cu refers to a 75% purity Al-Cu master alloy, in which Cu accounts for 75% by mass; Al-75Cr refers to a 75% purity Al-Cr master alloy, in which Cr accounts for 75% by mass. The batching temperature is 730℃, and the alloy chemical composition of the resulting molten alloy meets the alloy element composition of the 5657 aluminum alloy sheet blank for cosmetic container caps described in Example 3.

[0064] 2) Refining: The alloy liquid obtained after batching in step 1) is refined. The furnace induction time is 49 min. After the furnace induction is completed, 100% pure argon gas and sodium-free refining agent (environmentally friendly solid granular refining agent) are mixed to purify the aluminum melt. The amount of sodium-free refining agent added is 0.7 kg / 1000 kg of aluminum melt. After refining in the static furnace, the hydrogen content is controlled to be 0.18 ml / 100 g (Al). The rotor speed of the degassing box is 370 r / min. After degassing and purification, online degassing is performed, and the hydrogen content is controlled to be 0.120 ml / 100 g (Al). The refining temperature is controlled at 730℃ and the refining time is 50 min. After refining, slag is removed and the mixture is allowed to stand for 30 min.

[0065] 3) Casting: The aluminum alloy liquid obtained after refining in step 2) is subjected to online primary plate filtration, online degassing, secondary plate filtration and tubular filtration in sequence. The alloy liquid obtained after filtration is cast into aluminum alloy flat ingots.

[0066] The primary and secondary plate filters have a filter resolution of 40 ppi and 60 ppi, respectively. The casting temperature is 705℃, the casting speed is 47 mm / min, and the water flow rate is set to 60 m³ / min. 3 / piece, the length of the cast aluminum alloy flat ingot is 6350mm. After casting, wait for the end of the ingot gate to cool fully, then turn off the water circulation cooling after 15 minutes before hoisting.

[0067] 4) Sawing and milling: The aluminum alloy flat ingot obtained in step 3) is first sawed with a saw head of 400mm and a saw tail of 150mm; then the surface is milled, with a single-sided milling amount of 20mm on the large surface and 7.5mm on the small surface (to ensure that the surface is free of obvious defects such as pores, slag inclusions, unmilled areas, cold shuts, cracks, dents, oil stains, etc.), and a clean ingot is obtained after milling.

[0068] 5) Homogenization heat treatment: The cleaned ingots obtained in step 4) are placed in a heating furnace for homogenization heat treatment;

[0069] The specific process of the homogenization heat treatment is as follows: the heating process is carried out in stages, with the furnace gas temperature set at 400℃-430℃-460℃-490℃-520℃ respectively. After each stage reaches the set furnace gas temperature target value, the temperature is held for 2 hours before starting the next stage, until the final heating stage is completed. The heating time is 18 hours. At the beginning of the holding period, the metal temperature is controlled at 490℃ and the holding time is 7 hours, after which the metal is removed from the furnace.

[0070] 6) Hot rough rolling: The slab obtained after heat treatment in step 5) is rolled into an intermediate plate with a thickness of 35mm through 21 passes of rough rolling. The entry temperature of the rough rolling is 495℃.

[0071] 7) Hot finishing rolling: The hot-rolled intermediate plate obtained in step 6) is rolled into a hot-rolled billet coil with a thickness of 7.0 mm through 4 passes of hot continuous rolling. The finishing rolling inlet temperature is 400℃ and the finishing rolling temperature is 289℃. After leaving the mill, it is allowed to cool down naturally.

[0072] 8) Cold rolling: The aluminum alloy billet obtained in step 7) is naturally cooled to 45°C and then cold rolled. The total rolling rate is 71%, the pass distribution is 7.0-3.8-2.0mm, the uncoiling tension is set to 40-45KN, the coiling tension is set to 60-100KN, and the rolling speed is 280-320m / min, to obtain a cold rolled coil with an intermediate thickness of 2.0mm.

[0073] 9) Intermediate annealing: The intermediate thickness cold-rolled coil obtained in step 8) is subjected to intermediate annealing. The furnace gas temperature is set to 240°C in the first stage, oil is blown for 2 hours, and nitrogen is used for protection. The furnace gas temperature is set to 380°C in the second stage, and the metal temperature is raised to 310°C. The furnace gas temperature is changed to 330°C in the third stage, and the temperature is held for 3 hours. After exiting the furnace, the metal is quickly cooled by air.

[0074] 10) Cold-rolled finished product: The intermediate thickness coil after intermediate annealing in step 9) is cooled to 40°C by air cooling, and then cold-rolled. The total rolling rate is 80%, the pass distribution is 2.0-1.3-0.8-0.58-0.4mm, the uncoiling tension setting range is 22~45KN, the coiling tension setting range is 20~55KN, and the stable rolling speed range is 340~700m / min. After cold rolling, a cold-rolled coil with a thickness of 0.4mm is obtained.

[0075] 11) Surface alkaline washing: The cold-rolled finished coil obtained in step 10) is subjected to surface alkaline washing treatment. The temperature is set to 68℃, the linear speed is set to 70m / min, and the alkaline concentration is set to 2%.

[0076] 12) Cutting and packaging: Cool the roll material obtained in step 11) to room temperature and then package the resulting sheet material horizontally.

[0077] The mechanical comparison data of the 5657 aluminum alloy sheet for cosmetic container caps prepared in Example 4 of this invention are detailed in Table 3.

[0078] Table 3. Performance test data of the product prepared in Example 4 of the present invention.

[0079]

[0080] Example 5:

[0081] The cosmetic container cap of this invention is made of 5657 aluminum alloy sheet, expressed as a percentage by mass. Its alloy chemical composition is: Si 0.029%, Fe 0.066%, Cu 0.042%, Mn 0.0020%, Mg 0.712%, Cr 0.0005%, Zn 0.0059%, and Ti 0.022%, with the balance being Al and unavoidable impurities.

[0082] Example 6:

[0083] The detailed steps of the preparation method of the 5657 aluminum alloy sheet for cosmetic container caps described in Embodiment 5 of the present invention are as follows:

[0084] 1) Smelting: The raw material, pure aluminum ingots, is added to a flame-reflective furnace for heating and smelting (the pure aluminum ingots consist of 65% aluminum ingots with a purity of 99.85% and 35% aluminum ingots with a purity of 99.90%). The smelting temperature in the furnace is controlled at 740℃. After all the raw materials in the furnace have melted, the slag is removed by stirring to obtain the original alloy liquid. Then, 100% pure magnesium ingots, Al-75Cr, Al-75Cu, and Al-5Ti-B are added to the obtained original alloy liquid for batching (Al-75... Cu refers to a 75% purity Al-Cu master alloy, in which Cu accounts for 75% by mass; Al-75Cr refers to a 75% purity Al-Cr master alloy, in which Cr accounts for 75% by mass. The batching temperature is 735℃, and the alloy chemical composition of the resulting molten alloy meets the alloy element composition of the 5657 aluminum alloy sheet blank for cosmetic container caps described in Example 5.

[0085] 2) Refining: The alloy liquid obtained after batching in step 1) is refined. The furnace induction time is 50 minutes. After the furnace induction is completed, 100% pure argon gas and sodium-free refining agent (environmentally friendly solid granular refining agent) are mixed to purify the aluminum melt. The amount of sodium-free refining agent added is 0.6 kg / 1000 kg of aluminum melt. After refining in the static furnace, the hydrogen content is controlled to be 0.20 ml / 100 g (Al). The rotor speed of the degassing box is 380 r / min. After degassing and purification, online degassing is performed, and the hydrogen content is controlled to be 0.118 ml / 100 g (Al). The refining temperature is controlled at 735℃ and the refining time is 60 minutes. After refining, slag is removed and the mixture is allowed to stand for 40 minutes.

[0086] 3) Casting: The aluminum alloy liquid obtained after refining in step 2) is subjected to online primary plate filtration, online degassing, secondary plate filtration and tubular filtration in sequence. The alloy liquid obtained after filtration is cast into aluminum alloy flat ingots.

[0087] The primary and secondary plate filters have a filter resolution of 40 ppi and 60 ppi, respectively. The casting temperature is 715℃, the casting speed is 48 mm / min, and the water flow rate is set to 65 m³ / min. 3 / piece, the length of the cast aluminum alloy flat ingot is 6400mm. After casting, wait for the end of the ingot gate to cool fully and solidify. After cooling for 15 minutes, turn off the water circulation cooling and then hoist it.

[0088] 4) Sawing and milling: The aluminum alloy flat ingot obtained in step 3) is first sawed with a saw head of 450mm and a saw tail of 200mm; then it is milled, with a single-sided milling amount of 25mm on the large surface and 10mm on the small surface (to ensure that the surface is free of obvious defects such as pores, slag inclusions, unmilled areas, cold shuts, cracks, dents, oil stains, etc.). After milling, a clean ingot is obtained.

[0089] 5) Homogenization heat treatment: The cleaned ingots obtained in step 4) are placed in a heating furnace for homogenization heat treatment;

[0090] The specific process of the homogenization heat treatment is as follows: the heating process is carried out in stages, with the furnace gas temperature set at 400℃-430℃-460℃-490℃-520℃ respectively. After each stage reaches the set furnace gas temperature target value, the temperature is held for 2 hours before starting the next stage, until the final heating stage is completed. The heating time is 19 hours. At the beginning of the holding period, the metal temperature is controlled at 495℃ and the holding time is 6.5 hours, after which the metal is removed from the furnace.

[0091] 6) Hot rough rolling: The slab obtained after heat treatment in step 5) is rolled into an intermediate plate with a thickness of 37mm through 19 passes of rough rolling. The entry temperature of the rough rolling is 505℃.

[0092] 7) Hot finishing rolling: The hot-rolled intermediate plate obtained in step 6) is rolled into a hot-rolled billet coil with a thickness of 7.0 mm through 4 passes of hot continuous rolling. The finishing rolling inlet temperature is 410℃ and the finishing rolling temperature is 300℃. After leaving the mill, it is allowed to cool down naturally.

[0093] 8) Cold rolling: The aluminum alloy billet obtained in step 7) is naturally cooled to 40°C and then cold rolled. The total rolling rate is 71%, the pass distribution is 7.0-3.8-2.0mm, the uncoiling tension is set to 40-45KN, the coiling tension is set to 60-100KN, and the rolling speed is 280-320m / min to obtain a cold rolled coil with an intermediate thickness of 2.0mm.

[0094] 9) Intermediate annealing: The intermediate thickness cold-rolled coil obtained in step 8) is subjected to intermediate annealing. The furnace gas temperature is set to 240°C in the first stage, oil is blown for 2 hours, and nitrogen is used for protection. The furnace gas temperature is set to 380°C in the second stage, and the metal temperature is raised to 310°C. The furnace gas temperature is changed to 330°C in the third stage, and the temperature is held for 3 hours. After exiting the furnace, the metal is quickly cooled by air.

[0095] 10) Cold-rolled finished product: The intermediate thickness coil after intermediate annealing in step 9) is cooled to 40°C by air cooling, and then cold-rolled. The total rolling rate is 80%, the pass distribution is 2.0-1.3-0.8-0.58-0.4mm, the uncoiling tension setting range is 22~45KN, the coiling tension setting range is 20~55KN, and the stable rolling speed range is 340~700m / min. After cold rolling, a cold-rolled coil with a thickness of 0.4mm is obtained.

[0096] 11) Surface alkaline washing: The cold-rolled finished coil obtained in step 10) is subjected to surface alkaline washing treatment. The temperature is set to 70℃, the linear speed is set to 80m / min, and the alkaline concentration is set to 2%.

[0097] 12) Cutting and packaging: Cool the roll material obtained in step 11) to room temperature and then package the resulting sheet material horizontally.

[0098] The mechanical comparison data of the 5657 aluminum alloy sheet for cosmetic container caps prepared in Example 6 of this invention are detailed in Table 4.

[0099] Table 4. Performance test data of the product prepared in Example 6 of the present invention.

[0100]

[0101] Example 7:

[0102] The cosmetic container cap of this invention is made of 5657 aluminum alloy sheet, expressed as a percentage by mass. Its alloy chemical composition is as follows: Si 0.038%, Fe 0.068%, Cu 0.046%, Mn 0.0022%, Mg 0.720%, Cr 0.0005%, Zn 0.0061%, and Ti 0.020%, with the balance being Al and unavoidable impurities.

[0103] Example 8:

[0104] The detailed steps of the preparation method of the 5657 aluminum alloy sheet for cosmetic container caps described in Embodiment 7 of the present invention are as follows:

[0105] 1) Smelting: The raw material, pure aluminum ingots, is added to a flame-reflective furnace for heating and smelting (the pure aluminum ingots consist of 66% aluminum ingots with a purity of 99.85% and 34% aluminum ingots with a purity of 99.90%). The smelting temperature in the furnace is controlled at 745℃. After all the raw materials in the furnace have melted, the slag is removed by stirring to obtain the original alloy liquid. Then, 100% pure magnesium ingots, Al-75Cr, Al-75Cu, and Al-5Ti-B are added to the obtained original alloy liquid for batching (Al-75... Cu refers to a 75% purity Al-Cu master alloy, in which Cu accounts for 75% by mass; Al-75Cr refers to a 75% purity Al-Cr master alloy, in which Cr accounts for 75% by mass. The batching temperature is 740℃, and the alloy chemical composition of the resulting molten alloy meets the alloy element composition of the 5657 aluminum alloy sheet blank for cosmetic container caps described in Example 7.

[0106] 2) Refining: The alloy liquid obtained after batching in step 1) is refined. The furnace induction time is 40 minutes. After the furnace induction is completed, 100% pure argon gas and sodium-free refining agent (environmentally friendly solid granular refining agent) are mixed to purify the aluminum melt. The amount of sodium-free refining agent added is 0.65 kg / 1000 kg of aluminum melt. After refining in the static furnace, the hydrogen content is controlled to be 0.175 ml / 100 g (Al). The rotor speed of the degassing box is 360 r / min. After degassing and purification, online degassing is performed, and the hydrogen content is controlled to be 0.122 ml / 100 g (Al). The refining temperature is controlled at 740℃ and the refining time is 55 minutes. After refining, slag is removed and the mixture is allowed to stand for 20 minutes.

[0107] 3) Casting: The aluminum alloy liquid obtained after refining in step 2) is subjected to online primary plate filtration, online degassing, secondary plate filtration and tubular filtration in sequence. The alloy liquid obtained after filtration is cast into aluminum alloy flat ingots.

[0108] The primary and secondary plate filters have a filter resolution of 40 ppi and 60 ppi, respectively. The casting temperature is 699℃, the casting speed is 47 mm / min, and the water flow rate is set to 55 m³ / min. 3 / piece, the length of the cast aluminum alloy flat ingot is 6400mm. After casting, wait for the end of the ingot gate to cool fully and solidify. After cooling for 15 minutes, turn off the water circulation cooling and then hoist it.

[0109] 4) Sawing and milling: The aluminum alloy flat ingot obtained in step 3) is first sawed with a saw head of 300mm and a saw tail of 150mm; then it is milled, with a single-sided milling amount of 20mm on the large surface and 7mm on the small surface (to ensure that the surface is free of obvious defects such as pores, slag inclusions, unmilled areas, cold shuts, cracks, dents, oil stains, etc.). After milling, a clean ingot is obtained.

[0110] 5) Homogenization heat treatment: The cleaned ingots obtained in step 4) are placed in a heating furnace for homogenization heat treatment;

[0111] The specific process of the homogenization heat treatment is as follows: the heating process is carried out in stages, with the furnace gas temperature set at 400℃-430℃-460℃-490℃-520℃ respectively. After each stage reaches the set furnace gas temperature target value, the temperature is held for 2 hours before starting the next stage, until the final heating stage is completed. The heating time is 18 hours. At the beginning of the holding period, the metal temperature is controlled at 485℃ and the holding time is 8 hours, after which the metal is removed from the furnace.

[0112] 6) Hot rough rolling: The slab obtained after heat treatment in step 5) is rolled into an intermediate plate with a thickness of 34 mm through 21 passes of rough rolling. The entry temperature of the rough rolling is 497℃.

[0113] 7) Hot finishing rolling: The hot-rolled intermediate plate obtained in step 6) is rolled into a hot-rolled billet coil with a thickness of 7.0 mm through 4 passes of hot continuous rolling. The finishing rolling inlet temperature is 399℃ and the finishing rolling temperature is 290℃. After leaving the mill, it is allowed to cool down naturally.

[0114] 8) Cold rolling: The aluminum alloy billet obtained in step 7) is naturally cooled to 40°C and then cold rolled. The total rolling rate is 71%, the pass distribution is 7.0-3.8-2.0mm, the uncoiling tension is set to 40-45KN, the coiling tension is set to 60-100KN, and the rolling speed is 280-320m / min to obtain a cold rolled coil with an intermediate thickness of 2.0mm.

[0115] 9) Intermediate annealing: The intermediate thickness cold-rolled coil obtained in step 8) is subjected to intermediate annealing. The furnace gas temperature is set to 240°C in the first stage, oil is blown for 2 hours, and nitrogen is used for protection. The furnace gas temperature is set to 380°C in the second stage, and the metal temperature is raised to 310°C. The furnace gas temperature is changed to 330°C in the third stage, and the temperature is held for 3 hours. After exiting the furnace, the metal is quickly cooled by air.

[0116] 10) Cold-rolled finished product: The intermediate thickness coil after intermediate annealing in step 9) is cooled to 40°C by air cooling, and then cold-rolled. The total rolling rate is 80%, the pass distribution is 2.0-1.3-0.8-0.58-0.4mm, the uncoiling tension setting range is 22~45KN, the coiling tension setting range is 20~55KN, and the stable rolling speed range is 340~700m / min. After cold rolling, a cold-rolled coil with a thickness of 0.4mm is obtained.

[0117] 11) Surface alkaline washing: The cold-rolled finished coil obtained in step 10) is subjected to surface alkaline washing treatment. The temperature is set to 71℃, the linear speed is set to 65m / min, and the alkaline concentration is set to 2%.

[0118] 12) Cutting and packaging: Cool the roll material obtained in step 11) to room temperature and then package the resulting sheet material horizontally.

[0119] The mechanical comparison data of the 5657 aluminum alloy sheet for cosmetic container caps prepared in Example 8 of this invention are detailed in Table 5.

[0120] Table 5. Performance test data of the product prepared in Example 8 of this invention.

[0121]

[0122] Example 9:

[0123] The cosmetic container cap of this invention is made of 5657 aluminum alloy sheet, expressed as a percentage by mass. Its alloy chemical composition is as follows: Si 0.026%, Fe 0.061%, Cu 0.043%, Mn 0.0024%, Mg 0.725%, Cr 0.0004%, Zn 0.0063%, and Ti 0.0189%, with the balance being Al and unavoidable impurities.

[0124] Example 10:

[0125] The detailed steps of the preparation method of the 5657 aluminum alloy sheet for cosmetic container caps described in Embodiment 9 of the present invention are as follows:

[0126] 1) Smelting: The raw material, pure aluminum ingots, is added to a flame-reflective furnace for heating and smelting (the pure aluminum ingots consist of 69% aluminum ingots with a purity of 99.85% and 31% aluminum ingots with a purity of 99.90%). The smelting temperature in the furnace is controlled at 735℃. After all the raw materials in the furnace have melted, the slag is removed by stirring to obtain the original alloy liquid. Then, 100% pure magnesium ingots, Al-75Cr, Al-75Cu, and Al-5Ti-B are added to the obtained original alloy liquid for batching (Al-75... Cu refers to a 75% purity Al-Cu master alloy, in which Cu accounts for 75% by mass; Al-75Cr refers to a 75% purity Al-Cr master alloy, in which Cr accounts for 75% by mass. The batching temperature is 736℃. After batching, the alloy liquid obtained by melting the alloy meets the alloy element composition of the 5657 aluminum alloy sheet blank for cosmetic container caps described in Example 9.

[0127] 2) Refining: The alloy liquid obtained after batching in step 1) is refined. The furnace induction time is 60 minutes. After the furnace induction is completed, 100% pure argon gas and sodium-free refining agent (environmentally friendly solid granular refining agent) are mixed to purify the aluminum melt. The amount of sodium-free refining agent added is 0.75 kg / 1000 kg of aluminum melt. After refining in the static furnace, the hydrogen content is controlled to be 0.185 ml / 100 g (Al). The rotor speed of the degassing box is 375 r / min. After degassing and purification, online degassing is performed, and the hydrogen content is controlled to be 0.119 ml / 100 g (Al). The refining temperature is controlled at 735℃ and the refining time is 45 minutes. After refining, slag is removed and the mixture is allowed to stand for 35 minutes.

[0128] 3) Casting: The aluminum alloy liquid obtained after refining in step 2) is subjected to online primary plate filtration, online degassing, secondary plate filtration and tubular filtration in sequence. The alloy liquid obtained after filtration is cast into aluminum alloy flat ingots.

[0129] The primary and secondary plate filters have a filter resolution of 40 ppi and 60 ppi, respectively. The casting temperature is 709℃, the casting speed is 46 mm / min, and the water flow rate is set to 50 m³ / min. 3 / piece, the length of the cast aluminum alloy flat ingot is 6400mm. After casting, wait for the end of the ingot gate to cool fully and solidify. After cooling for 15 minutes, turn off the water circulation cooling and then hoist it.

[0130] 4) Sawing and milling: The aluminum alloy flat ingot obtained in step 3) is first sawed with a saw head of 300mm and a saw tail of 100mm; then it is milled, with a single-sided milling amount of 20mm on the large surface and 10mm on the small surface (to ensure that the surface is free of obvious defects such as pores, slag inclusions, unmilled areas, cold shuts, cracks, dents, oil stains, etc.). After milling, a clean ingot is obtained.

[0131] 5) Homogenization heat treatment: The cleaned ingots obtained in step 4) are placed in a heating furnace for homogenization heat treatment;

[0132] The specific process of the homogenization heat treatment is as follows: the heating process is carried out in stages, with the furnace gas temperature set at 400℃-430℃-460℃-490℃-520℃ respectively. After each stage reaches the set furnace gas temperature target value, the temperature is held for 2 hours before starting the next stage, until the final heating stage is completed. The heating time is 18 hours. At the beginning of the holding period, the metal temperature is controlled at 485℃ and the holding time is 8 hours, after which the metal is removed from the furnace.

[0133] 6) Hot rough rolling: The slab obtained after heat treatment in step 5) is rolled into an intermediate plate with a thickness of 34 mm through 21 passes of rough rolling. The entry temperature of the rough rolling is 499℃.

[0134] 7) Hot finishing rolling: The hot-rolled intermediate plate obtained in step 6) is rolled into a hot-rolled billet coil with a thickness of 7.0 mm through 4 passes of hot continuous rolling. The finishing rolling inlet temperature is 396℃ and the finishing rolling temperature is 295℃. After leaving the mill, it is allowed to cool down naturally.

[0135] 8) Cold rolling: The aluminum alloy billet obtained in step 7) is naturally cooled to 40°C and then cold rolled. The total rolling rate is 71%, the pass distribution is 7.0-3.8-2.0mm, the uncoiling tension is set to 40-45KN, the coiling tension is set to 60-100KN, and the rolling speed is 280-320m / min to obtain a cold rolled coil with an intermediate thickness of 2.0mm.

[0136] 9) Intermediate annealing: The intermediate thickness cold-rolled coil obtained in step 8) is subjected to intermediate annealing. The furnace gas temperature is set to 240°C in the first stage, oil is blown for 2 hours, and nitrogen is used for protection. The furnace gas temperature is set to 380°C in the second stage, and the metal temperature is raised to 310°C. The furnace gas temperature is changed to 330°C in the third stage, and the temperature is held for 3 hours. After exiting the furnace, the metal is quickly cooled by air.

[0137] 10) Cold-rolled finished product: The intermediate thickness coil after intermediate annealing in step 9) is cooled to 40°C by air cooling, and then cold-rolled. The total rolling rate is 80%, the pass distribution is 2.0-1.3-0.8-0.58-0.4mm, the uncoiling tension setting range is 22~45KN, the coiling tension setting range is 20~55KN, and the stable rolling speed range is 340~700m / min. After cold rolling, a cold-rolled coil with a thickness of 0.4mm is obtained.

[0138] 11) Surface alkaline washing: The cold-rolled finished coil obtained in step 10) is subjected to surface alkaline washing treatment. The temperature is set to 65℃, the linear speed is set to 75m / min, and the alkaline concentration is set to 2%.

[0139] 12) Cutting and packaging: Cool the roll material obtained in step 11) to room temperature and then package the resulting sheet material horizontally.

[0140] The mechanical comparison data of the 5657 aluminum alloy sheet for cosmetic container caps prepared in Example 10 of this invention are detailed in Table 6.

[0141] Table 6. Performance test data of the product prepared in Example 10 of the present invention.

[0142]

Claims

1. A 5657 aluminum alloy sheet for a cosmetic container cap, characterized in that, The alloy chemical composition of the 5657 aluminum alloy sheet used for the cosmetic container cap, expressed as a percentage by mass, is as follows: Si 0-0.075%, Fe 0-0.09%, Cu 0.04-0.08%, Mn 0-0.02%, Mg 0.65-0.8%, Cr 0-0.02%, Zn 0-0.03%, and Ti 0.015-0.025%, with the balance being Al and unavoidable impurities. The method for preparing the 5657 aluminum alloy sheet for the cosmetic container cap includes the following steps: 1) Smelting: Pure aluminum ingots are added to a flame reverberatory furnace for heating and smelting. The smelting temperature in the furnace is controlled at 720-760℃. After all the raw materials in the furnace have melted, the slag is removed by stirring to obtain the original alloy liquid. Then, 100% pure magnesium ingots, Al-75Cr, Al-75Cu and Al-5Ti-B are added to the original alloy liquid for batching at a temperature of 725-740℃. After batching, the alloy chemical composition of the alloy liquid obtained by smelting meets the alloy element chemical composition of the 5657 aluminum alloy sheet blank for cosmetic container caps. 2) Refining: The alloy liquid obtained after batching in step 1) is refined. The furnace induction time is 40-60 minutes. After the furnace induction is completed, the refining is carried out by mixing gas with environmentally friendly solid particle refining agent. The refining temperature is controlled at 725-740℃ and the refining time is 40-120 minutes. After the refining is completed, the slag is removed and the mixture is allowed to stand for 20-50 minutes. 3) Casting: The aluminum alloy liquid obtained after refining in step 2) is subjected to online primary plate filtration, online degassing, secondary plate filtration and tubular filtration in sequence. The alloy liquid obtained after filtration is cast into aluminum alloy flat ingots. 4) Sawing and milling: The aluminum alloy flat ingot obtained in step 3) is first sawed, with a saw head of 300-500mm and a saw tail of 100-200mm; then the surface is milled, with a single-sided milling amount of 15-25mm for the large surface and 5-10mm for the small surface, and a clean ingot is obtained after milling. 5) Homogenization heat treatment: The cleaned ingots obtained in step 4) are placed in a heating furnace for homogenization heat treatment; the specific process of homogenization heat treatment is as follows: the heating process is carried out in stages, and the furnace gas temperature is set to 400℃-430℃-460℃-490℃-520℃ respectively. After each stage reaches the set furnace gas temperature target value, the temperature is held for 2 hours before starting the next stage, until the final heating stage is completed. The heating time is 17-19 hours; the metal temperature is controlled at 485-505℃ and the holding time is 6-8 hours, after which the ingots are removed from the furnace. 6) Hot rough rolling: The slab obtained after heat treatment in step 5) is rolled into an intermediate plate with a thickness of 33-37 mm by 19-23 passes of rough rolling. The entry temperature of the rough rolling is 480-510℃. 7) Hot finishing rolling: The hot-rolled intermediate plate obtained in step 6) is rolled into a hot-rolled billet coil with a thickness of 7.0 mm through 4 passes of hot continuous rolling. The finishing rolling inlet temperature is 390-410℃ and the finishing rolling temperature is 285-300℃. After leaving the mill, it is allowed to cool down naturally. 8) Cold rolling: The aluminum alloy billet obtained in step 7) is naturally cooled to ≤50℃, and then cold rolled to obtain a cold-rolled coil with an intermediate thickness of 2.0mm; 9) Intermediate annealing: The intermediate thickness cold-rolled coil obtained in step 8) is subjected to intermediate annealing; 10) Cold-rolled finished product: The intermediate thickness coil after intermediate annealing in step 9) is cooled to ≤40℃ by air cooling, and then cold-rolled. The total rolling processing rate is 80%. After cold rolling, a cold-rolled coil with a thickness of 0.4mm is obtained. 11) Surface alkaline washing: The cold-rolled finished coil obtained in step 10) is subjected to surface alkaline washing treatment; 12) Cutting and packaging: Cool the roll material obtained in step 11) to room temperature and then package the resulting sheet material horizontally.

2. The 5657 aluminum alloy sheet for cosmetic container caps according to claim 1, characterized in that: Expressed as a percentage by mass, the raw material pure aluminum ingots mentioned in step 1) consist of 65-70% aluminum ingots with a purity of 99.85% and 30-35% aluminum ingots with a purity of 99.90%.

3. The 5657 aluminum alloy sheet for cosmetic container caps according to claim 1, characterized in that: In step 2), the gas is 100% pure argon, and the environmentally friendly solid particle refining agent is a sodium-free refining agent. During the refining process, the amount of sodium-free refining agent added to the furnace is 0.6-0.8 kg of sodium-free refining agent per 1000 kg of aluminum melt, so that the hydrogen content after refining in the static furnace is <0.20 ml / 100 g Al, and the rotor speed of the degassing box is 350-380 r / min. After refining, online degassing is performed to control the hydrogen content to ≤0.15 ml / 100 g Al.

4. The 5657 aluminum alloy sheet for cosmetic container caps according to claim 1, characterized in that: In step 3), the primary and secondary plate filters have a filter resolution of 40 ppi and 60 ppi, respectively. The casting temperature is 690–720℃, the casting speed is 46–48 mm / min, and the water flow rate is set to 50–70 m³ / min. 3 / piece, the length of the cast aluminum alloy flat ingot is 6200-6400mm. After casting, wait for the end of the ingot gate to cool fully, then turn off the water circulation cooling after 15 minutes before hoisting.

5. The 5657 aluminum alloy sheet for cosmetic container caps according to claim 1, characterized in that: In step 8), during the cold rolling process, the pass distribution is 7.0-3.8-2.0 mm, the uncoiling tension is set to 40-45 KN, the coiling tension is set to 60-100 KN, and the rolling speed is 280-320 m / min.

6. The 5657 aluminum alloy sheet for cosmetic container caps according to claim 1, characterized in that: In the intermediate annealing process described in step 9), the furnace gas temperature is set to 240°C in the first stage, oil is blown for 2 hours, and nitrogen is used for protection; the furnace gas temperature is set to 380°C in the second stage, and the metal temperature is raised to 310°C; in the third stage, the furnace gas temperature is changed to 330°C, the temperature is held for 3 hours, and the metal is rapidly cooled by air after being taken out of the furnace.

7. The 5657 aluminum alloy sheet for cosmetic container caps according to claim 1, characterized in that: In step 10), during the cold rolling process, the pass distribution is 2.0-1.3-0.8-0.58-0.4mm, the uncoiling tension is set to 22-45KN, the coiling tension is set to 20-55KN, and the rolling speed is 340-700m / min.

8. The 5657 aluminum alloy sheet for cosmetic container caps according to claim 1, characterized in that: In step 11), the surface alkaline washing process is set to a temperature of 60-75°C, a linear speed of 50-80 m / min, and an alkaline concentration of 2%.

Images