Aluminum alloy sheet for high-strength ultra-thin low-depth draw ear rate can body and preparation method thereof

Abstract

The application discloses a kind of high-strength ultra-thin low deep-drawing ear rate can body aluminum alloy plate and preparation method thereof, high-strength ultra-thin low deep-drawing ear rate can body aluminum alloy plate is obtained by being sequentially subjected to homogenization treatment, hot rolling and cold rolling to 3104 aluminum alloy ingot, the rolling speed of the hot rolling is determined according to the size of second phase particle in the ingot;The ear rate of the high-strength ultra-thin low deep-drawing ear rate can body aluminum alloy plate is less than or equal to 1.5%.The application can realize that high-strength ultra-thin tank material forms strong cubic texture after hot finish rolling and coiling, balances cold rolling deformation texture and reduces ear rate, solves the problem that ear rate is also significantly increased while high alloying improves strength of ultra-thin tank material.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy plastic processing technology, and more specifically, to a high-strength, ultra-thin aluminum alloy sheet for can bodies with low deep-drawing lug rate and its preparation method. The method mainly involves controlling the second phase particles and crystallographic texture through ingot heat treatment and multi-stand hot rolling to reduce the deep-drawing lug rate and the can breakage and leakage rate. Background Technology

[0002] 3104 aluminum alloy, due to its excellent formability and high strength, is an ideal material for manufacturing beverage can bodies, resulting in a huge market demand. Hot rolling of ingots is a crucial step in the production of can body materials. However, with the trend towards thinner profiles, the coarse compounds in the alloy have led to increasingly prominent issues such as can breakage / leakage during deep drawing. Simultaneously, during hot rolling, second-phase particles reduce the cubic texture content formed by "self-annealing" after multi-stand hot continuous rolling through grain boundary pinning and particle-induced nucleation (PSN) mechanisms, thereby increasing the rate of can breakage during deep drawing. The homogenization heat treatment method for aluminum alloy ingots used in beverage can bodies (CN 200610095103.6) proposes a high-temperature homogenization treatment in a pusher furnace equipped with a cooling device, first performing a high-temperature homogenization treatment at 550-620℃ for 12-24 hours to eliminate the segregation of Mn-dominant components. Then, it is forcibly cooled to 460℃-500℃ at a cooling rate of 20-60℃ / hour and held at this temperature for 6-12 hours to control the size and distribution of precipitated phases, thereby ensuring the high-quality production of AA3104 aluminum alloy thin plates and strips. The hot continuous rolling method for aluminum alloy sheet and strip for beverage can bodies (CN 200610095112.5) involves multi-pass hot rough rolling with a total reduction of 93-96% on the basis of the above homogenization, followed by continuous rolling to a thickness of 2.0-3.0 mm using a 4-stand mill. This method achieves precise control over the shape and thickness of 3104 aluminum alloy sheet with 0.20% Si, 0.52% Fe, 0.18% Cu, 1.02% Mn, and 1.30% Mg, and significantly reduces the ear-making rate.

[0003] With the trend towards thinner can fillers, it is necessary to increase the content of alloying elements to improve strength. However, increasing the degree of alloying easily leads to the formation of a large number of coarse-sized second-phase compound particles. Studies have found that during deformation, local high dislocation density deformation zones with particle sizes are easily formed around these coarse second-phase particles, thus promoting recrystallization. However, this does not produce preferred-oriented grains or strengthen the recrystallized cubic texture. Therefore, since the recrystallization caused by a large number of coarse particles results in a non-cubic texture, even if complete recrystallization occurs after hot continuous rolling of high-alloy high-strength can filler alloys, it cannot significantly reduce the deep-drawing ear rate of the cold-rolled finished sheet. In other words, with the increase of alloying degree, the deep-drawing ear rate of the finished sheet increases under current process conditions.

[0004] This invention designs a high-strength, ultra-thin, low-deep-drawing lug-making rate aluminum alloy sheet for can bodies and its preparation method. Based on the alloy composition and particle size, it systematically increases the cubic texture content after hot continuous rolling and coiling, balances the cold-rolled deformation texture to reduce the lug-making rate, and solves the problem that while high alloying of ultra-thin can materials increases strength, the lug-making rate also increases significantly. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a high-strength, ultra-thin, low-deep-drawing lug-making rate aluminum alloy sheet for can bodies and its preparation method. Based on alloy composition and particle size, the cubic texture content after hot continuous rolling is systematically increased, and the cold-rolled deformation texture is balanced to reduce the lug-making rate. This solves the problem that while high alloying of ultra-thin can materials increases strength, the lug-making rate also increases significantly.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] The first aspect of the present invention provides an aluminum alloy sheet for high-strength, ultra-thin, low-depth-drawing can bodies with low lug ratios. The aluminum alloy sheet for high-strength, ultra-thin, low-depth-drawing can bodies with low lug ratios is prepared by sequentially homogenizing, hot-rolling, and cold-rolling a 3104 aluminum alloy ingot. The rolling speed of the hot rolling is determined according to the size of the second phase particles in the ingot.

[0008] The ear-making rate of the aluminum alloy sheet used for the high-strength, ultra-thin, low-depth drawing can body is ≤1.5%.

[0009] Preferably, the microstructure of the aluminum alloy sheet for the high-strength, ultra-thin, low-deep-drawing can body includes a strong cubic texture and a cold-rolled deformation texture, wherein the volume content of the strong cubic texture is 10-12% and the volume content of the cold-rolled deformation texture is 88-90%.

[0010] Preferably, the aluminum alloy sheet used for the high-strength, ultra-thin, low-deep-drawing can body has a thickness of 0.240–0.260 mm, a yield strength of 280–295 MPa, and a tensile strength of 300–320 MPa.

[0011] The second aspect of the present invention provides an aluminum alloy sheet for high-strength, ultra-thin, low-depth-drawing can bodies and a method for preparing the same, wherein a 3104 aluminum alloy ingot is subjected to homogenization treatment, hot rolling treatment and cold rolling treatment in sequence to obtain an aluminum alloy sheet for high-strength, ultra-thin, low-depth-drawing can bodies.

[0012] The homogenization process involves heating the 3104 aluminum alloy ingot to 450℃~610℃ at a heating rate of 100~120℃ / h and holding it at that temperature for 20~48h, followed by rapid cooling to the initial rolling temperature using strong air.

[0013] The rolling speed of the hot rolling process is determined based on the size of the second phase particles.

[0014] Preferably, during the homogenization process, the total cooling time and the holding time after cooling to the rolling temperature do not exceed 2 hours; the rolling temperature is 430–510°C.

[0015] Preferably, the hot rolling process includes hot roughing and hot finishing, wherein the rolling temperatures of the last three passes of the hot finishing are controlled at 390–440°C, 360–410°C and 320–340°C, respectively, and the deformation amounts of the last three passes of the hot finishing are controlled at 50±5%, 45±5% and 45±5%, respectively.

[0016] Preferably, during the hot rolling process, samples are taken before hot rolling and the average size of the second-phase particles is statistically analyzed using metallography or scanning electron microscopy. The rolling speed is determined based on the size of the second-phase particles. When the number density of particles larger than 1 μm in the second-phase particles is less than 10 particles / μm... 2 When the PSN effect is negligible, no control of the rolling speed is required, and it can generally be set to 2–7 m / s; when the number density of particles larger than 1 μm in the second phase is ≥10 particles / μm 2 hour.

[0017] The rolling speed is controlled as follows:

[0018] When the proportion of particles with an equivalent circular radius exceeding 5 μm exceeds 50%, the rolling speed is controlled according to the following formula:

[0019]

[0020] When the proportion of particles with an equivalent circular radius of 2–5 μm exceeds 50%, the rolling speed is controlled according to the following formula:

[0021]

[0022] When the proportion of particles with an equivalent circular radius < 1 μm exceeds 50%, the rolling speed is controlled according to the following formula:

[0023]

[0024] Where H and h are the plate thicknesses before and after the current rolling deformation, respectively, in meters; R is the gas constant, with a value of 8.314; T is the deformation temperature, in K; and R is the roll radius, in meters. The average radius of the second-phase particles is calculated based on the equivalent circle, in meters.

[0025] Preferably, during the cold rolling process, the total cold rolling deformation is controlled at 75-90%, the deformation per pass is controlled at 40-60%, and the final rolling temperature is controlled at 150-165℃.

[0026] Preferably, the high-strength, ultra-thin, low-deep-drawing aluminum alloy sheet for the can body has an ear-making rate of ≤1.5%, a thickness of 0.240~0.260mm, a yield strength of 280~295MPa, and a tensile strength of 300~320MPa.

[0027] Preferably, the microstructure of the aluminum alloy sheet for the high-strength, ultra-thin, low-deep-drawing can body includes a strong cubic texture and a cold-rolled deformation texture, wherein the volume content of the strong cubic texture is 10-12% and the volume content of the cold-rolled deformation texture is 88-90%.

[0028] The beneficial effects of this invention are as follows:

[0029] 1. This invention reduces the deep-drawing lug rate and the rate of broken or leaking containers by controlling the second-phase particles and crystallographic texture through ingot heat treatment and multi-stand hot rolling;

[0030] 2. This invention systematically increases the cubic texture content after hot continuous rolling and coiling based on the alloy composition and particle size of the material, thereby reducing the deep drawing earing rate of cold-rolled finished sheets;

[0031] 3. By controlling the second-phase particles in the alloy and the hot rolling process parameters, this invention reduces the adverse effects of the second-phase particles on the recrystallized cubic texture of hot-rolled coils while ensuring the strength of the can stock. It also increases the content of cubic texture after "self-annealing" of hot-rolled coils and reduces the deep drawing ear production rate of high-strength ultra-thin can stock. Attached Figure Description

[0032] Figure 1 This is a schematic flowchart of the method for preparing aluminum alloy sheet for ultra-thin, low-depth-drawing can bodies according to the present invention.

[0033] Figure 2 This is a particle size distribution diagram of the second phase ingot after homogenization treatment in Embodiment 1 of the present invention;

[0034] Figure 3 This is a particle size distribution diagram of the second phase ingot after homogenization treatment in Embodiment 2 of the present invention;

[0035] Figure 4 This is a scanning electron microscope image of the ingot after homogenization treatment in Embodiment 3 of the present invention. Detailed Implementation

[0036] To better understand the above-mentioned technical solutions of the present invention, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0037] This invention provides a high-strength, ultra-thin, low-depth-drawing aluminum alloy sheet for can bodies. The high-strength, ultra-thin, low-depth-drawing aluminum alloy sheet for can bodies is prepared by sequentially homogenizing, hot-rolling, and cold-rolling a 3104 aluminum alloy ingot. The rolling speed of the hot rolling is determined according to the size of the second-phase particles in the ingot. The ear-forming rate of the high-strength, ultra-thin, low-depth-drawing aluminum alloy sheet for can bodies is ≤1.5%.

[0038] The microstructure of the aforementioned high-strength, ultra-thin, low-depth-drawing aluminum alloy sheet for can bodies includes a strong cubic texture and a cold-rolled deformation texture. The volume content of the strong cubic texture is 10-12%, and the volume content of the cold-rolled deformation texture is 88-90%.

[0039] The aluminum alloy sheet used for the high-strength, ultra-thin, low-depth-drawing can body has a thickness of 0.240–0.260 mm, a yield strength of 280–295 MPa, and a tensile strength of 300–320 MPa.

[0040] The present invention also provides a method for preparing high-strength, ultra-thin, low-deep-drawing-ear-rate aluminum alloy sheet for tanks, which can systematically increase the cubic texture content after hot continuous rolling according to the alloy composition and the size of the second phase particles, thereby reducing the deep-drawing-ear-rate of the cold-rolled finished sheet.

[0041] In this invention, since recrystallization is essentially the formation and migration process of large-angle grain boundaries, and the driving force comes from deformation energy storage with dislocation density as the key parameter, the following grain boundary motion model is proposed, taking into account the local deformation region of coarse second-phase particles:

[0042] v = mP = m(P) av +P d -P Z )

[0043] Where v is the grain boundary migration velocity, m is the grain boundary mobility related to the grain boundary orientation difference, and P av To disregard uniform deformation energy storage in the case of local deformation regions around second-phase particles, P d For the additional deformation energy storage in the local deformation zone around the second-phase particles, P Z The magnitude of the pinning resistance of the second-phase particles to the grain boundaries is:

[0044]

[0045] Where f is the fraction of second-phase particles, γ is the interfacial energy between the second phase and the aluminum matrix, and r is the size of the second-phase particles; during deformation, the local deformation zone near the second-phase particles requires the particle size to reach a certain size so that the size of the local deformation zone is comparable to the critical nucleus size, that is, the critical size can be described by the following formula:

[0046]

[0047] Therefore, increasing the matrix dislocation density, i.e., P av This is the most important means to reduce the adverse effects of second-phase particles on recrystallization texture. This invention regulates the size of second-phase particles and the content of Mn element in the solid solution by controlling the homogenization of the ingot. It leverages the thermo-mechanical coupling effect of the interaction between solid solution atoms and dislocations during the hot working process to highlight the dislocation proliferation and suppress the dislocation reduction process, thereby controlling the dislocation density. Furthermore, by controlling the matching of the temperature and speed of the hot continuous rolling mill stand, the adverse effects of second-phase particles on the recrystallized cubic texture after hot continuous rolling are significantly reduced.

[0048] Combination Figure 1 As shown, the method for preparing high-strength, ultra-thin, low-depth-drawing aluminum alloy sheet for can bodies of the present invention involves sequentially subjecting a 3104 aluminum alloy ingot to homogenization treatment, hot rolling treatment, and cold rolling treatment to obtain a high-strength, ultra-thin, low-depth-drawing aluminum alloy sheet for can bodies; specifically as follows:

[0049] (1) Homogenization treatment: The 3104 aluminum alloy ingot is heated to 450℃~610℃ at a heating rate of 100~120℃ / h and held for 20~48h. Then it is rapidly cooled to the rolling temperature by strong wind.

[0050] In this step, the melting of non-equilibrium solidified AlFeMnSi compounds is avoided by controlling the heating rate. Holding at 450℃~610℃ ensures maximum dissolution of the semi-continuous casting process to form coarse compound particles and promotes the transformation of the insoluble β-AlFeMnSi phase to the α-AlFeMnSi phase, thus avoiding its adverse effects on the formation of cubic texture after subsequent hot rolling coiling and on deep drawing leaks / breaks.

[0051] In the homogenizing / heating furnace, a strong air rapid cooling method is used to rapidly cool the ingot from the homogenizing temperature of 450℃~610℃ to the rolling temperature of 430~510℃. The total cooling time and the holding time after cooling to the rolling temperature do not exceed 2 hours, so as to reduce the large amount of precipitation during the process.

[0052] (2) Hot rolling treatment

[0053] Hot rolling includes hot roughing and hot finishing. The rolling temperatures of the last three passes of hot finishing are controlled at 390–440℃, 360–410℃ and 320–340℃, respectively. If the temperature is higher than the target temperature range, spray cooling is required to bring the rolling temperature back to the target temperature range. The deformation of the last three passes of hot finishing is controlled at 50±5%, 45±5% and 45±5%, respectively.

[0054] Before hot rolling, samples are taken and the average size of the second-phase particles is statistically analyzed using metallography or scanning electron microscopy. The rolling speed is then determined based on the size of the second-phase particles.

[0055] When the number density of particles larger than 1 μm in the second phase is less than 10 particles / μm 2 When the PSN effect is negligible, no control of the rolling speed is required, and it can generally be set to 2–7 m / s; when the number density of particles larger than 1 μm in the second phase is ≥10 particles / μm 2 The rolling speed is controlled as follows:

[0056] a. When the proportion of particles with an equivalent circular radius exceeding 5μm exceeds 50%, the rolling speed is controlled according to the following formula:

[0057]

[0058] b. When the proportion of particles with an equivalent circular radius of 2–5 μm exceeds 50%, the rolling speed is controlled according to the following formula:

[0059]

[0060] c. When the proportion of particles with an equivalent circular radius < 1 μm exceeds 50%, the rolling speed is controlled according to the following formula:

[0061]

[0062] Where H and h are the plate thicknesses before and after the current rolling deformation, respectively, in meters; R is the gas constant, with a value of 8.314; T is the deformation temperature, in K; and R is the roll radius, in meters. The average radius of the second-phase particles is calculated based on the equivalent circle, in meters.

[0063] (3) Cold rolling

[0064] During the cold rolling process, the total cold rolling deformation is controlled at 75-90% to ensure that the remaining cubic texture is sufficient to "balance" the rolling texture, thereby controlling the earing rate to within 1.5%; the deformation per pass is controlled at 40-60%, and by controlling the deformation per pass and the rolling speed, the final rolling temperature is controlled at 150-165℃ to reduce the deep drawing breakage rate.

[0065] The high-strength, ultra-thin, low-deep-drawing aluminum alloy sheet for can bodies prepared by the above method has an ear-making rate of ≤1.5%, a thickness of 0.240~0.260mm, a yield strength of 280~295MPa, and a tensile strength of 300~320MPa.

[0066] The microstructure of the aforementioned high-strength, ultra-thin, low-depth-drawing aluminum alloy sheet for can bodies includes a strong cubic texture and a cold-rolled deformation texture. The volume content of the strong cubic texture is 10-12%, and the volume content of the cold-rolled deformation texture is 88-90%.

[0067] This invention controls the second-phase particles in the alloy and the hot rolling process parameters to reduce the adverse effects of the second-phase particles on the recrystallized cubic texture of hot-rolled coils while ensuring the strength of the can stock. This increases the content of cubic texture after "self-annealing" of hot-rolled coils and reduces the deep-drawing ear production rate of high-strength ultra-thin can stock.

[0068] Implementation Plan

[0069] Referring to Table 1, according to the method of this invention, different homogenization heat treatment processes are used to heat the 3104 ingot to 450℃~610℃ at a rate of 100~120℃ / h and hold it for 20~48h. Then, it is rapidly cooled to the initial rolling temperature of 430~510℃ using strong air. The total cooling time and the holding time to the initial rolling temperature do not exceed 2h. The size of the second phase particles in the ingot is detected using a scanning electron microscope, and the rolling speed for hot rolling is calculated accordingly. During hot rolling, a four-high mill with a roll diameter of 750mm (r=0.375m) is used for hot rolling on a three-stand hot rolling mill. Continuous rolling: First, hot roughing is performed to 25mm, followed by hot finishing rolling. In the last three passes of hot finishing rolling, the rolling temperatures are controlled at 390–440℃, 360–410℃, and 320–340℃, respectively, with a reduction of 50% per pass. Subsequently, cold rolling is performed, with the total deformation controlled at 75–90% and the deformation per pass controlled at 40–60%. The final rolling temperature is controlled at 150–165℃ to obtain high-strength, ultra-thin, low-depth-drawing aluminum alloy sheet for tank bodies. The earing rate can be tested according to the national standard "Test Method for Earing of Thin Plates and Strips of Metallic Materials" (GB / T 24183-2021), and the results are shown in Table 2.

[0070] Table 1

[0071] Homogenization heat treatment regime Continuous rolling start temperature Continuous rolling speed Example 1 600℃×20h 430℃ 3.0m / s Example 2 450℃×30h 430℃ 1.0m / s Example 3 610℃×48h 510℃ 2.0m / s Comparative Example 1 600℃×20h 430℃ 5.0m / s Comparative Example 2 450℃×30h 430℃ 2.0m / s

[0072] Figure 2 , Figure 3 The results show the particle size distribution of the second phase ingot after homogenization treatment in Examples 1 and 2, respectively. Since it is difficult to accurately count particles smaller than 1 μm, only particles larger than 1 μm are counted here. Figure 2 The image shows the particle statistical distribution after holding at 600℃ for 20 hours using scanning electron microscopy. As can be seen from the figure, the proportion of particles larger than 5μm reaches 89%, and the average particle size is 6.57μm. According to the formula, the critical rolling speed is calculated to be 4.0m / s. Therefore, the rolling speed for hot rolling is determined to be 3.0m / s. Figure 3 The image shows the particle statistical distribution after holding at 450℃ for 30 hours using scanning electron microscopy. As can be seen from the image, particles in the range of 2 to 5 μm account for 77%, and the average particle size is 4.26 μm. Based on the formula, the critical rolling speed is calculated to be 1.1 m / s. Therefore, the rolling speed for hot rolling is determined to be 1.0 m / s.

[0073] Figure 4 This is a scanning electron microscope (SEM) image of the hot-rolled sample from Example 3 after holding at 610℃ for 48 hours. The image shows that the particle number density (PDN) of particles larger than 1 μm is 8.9 particles / μm. 2 Therefore, the rolling speed for subsequent hot rolling can be 2.0 m / s.

[0074] Comparative Example 1 follows the preparation method in Example 1, except that the rolling speed for hot rolling is 5.0 m / s. Because the proportion of particles larger than 5 μm in the second phase of the ingot reaches 89% after homogenization, and the average particle size is 6.57 μm, according to the formula... The critical rolling speed was calculated to be 4.0 m / s; Comparative Example 2 followed the preparation method of Example 2, the difference being that the hot rolling speed was 2.0 m / s. Because the proportion of particles in the second phase of the ingot within the 2–5 μm range was 77% after homogenization, and the average particle size was 4.26 μm, according to the formula… The critical rolling speed was calculated to be 1.1 m / s. Therefore, according to Table 2, the rolling speeds of Comparative Example 1 and Comparative Example 2 exceeded the critical speed during hot rolling, resulting in a higher earing rate in the prepared plates.

[0075] Table 2

[0076]

[0077] As shown in Table 2, the high-strength, ultra-thin, low-depth-drawing aluminum alloy sheet for cans prepared in the embodiments of the present invention has an earing rate of ≤1.5%, a yield strength of 280-295 MPa, and a tensile strength of 300-320 MPa. The microstructure of the high-strength, ultra-thin, low-depth-drawing aluminum alloy sheet for cans prepared in the embodiments of the present invention is mainly a strong cubic texture and a cold-rolled deformation texture, with a volume content of 10-12% for the strong cubic texture and 88-90% for the cold-rolled deformation texture.

[0078] In summary, by controlling the second-phase particles in the alloy and the hot rolling process parameters, this invention reduces the adverse effects of the second-phase particles on the recrystallized cubic texture of the hot-rolled coil while ensuring the strength of the can stock, increases the content of the cubic texture after the hot-rolled coil "self-annealing", and reduces the deep drawing ear production rate of high-strength ultra-thin can stock.

[0079] Those skilled in the art should recognize that the above embodiments are merely illustrative of the present invention and are not intended to limit the present invention. Any variations or modifications to the above embodiments that are within the spirit and essence of the present invention will fall within the scope of the claims of the present invention.

Claims

1. A high-strength, ultra-thin, low-depth-drawing aluminum alloy sheet for can bodies, characterized in that, The high-strength, ultra-thin, low-deep-drawing aluminum alloy sheet for the can body is prepared by sequentially homogenizing, hot-rolling, and cold-rolling a 3104 aluminum alloy ingot. The rolling speed of the hot rolling is determined according to the size of the second phase particles in the ingot. The ear-making rate of the aluminum alloy sheet used for the high-strength, ultra-thin, low-depth drawing can body is ≤1.5%.

2. The high-strength, ultra-thin, low-depth-drawing aluminum alloy sheet for can bodies according to claim 1, characterized in that, The microstructure of the aluminum alloy sheet for high-strength, ultra-thin, low-deep-drawing can body includes a strong cubic texture and a cold-rolled deformation texture. The volume content of the strong cubic texture is 10-12%, and the volume content of the cold-rolled deformation texture is 88-90%.

3. The high-strength, ultra-thin, low-depth-drawing aluminum alloy sheet for can bodies according to claim 1, characterized in that, The aluminum alloy sheet used for the high-strength, ultra-thin, low-deep-drawn can body has a thickness of 0.240–0.260 mm, a yield strength of 280–295 MPa, and a tensile strength of 300–320 MPa.

4. A method for preparing a high-strength, ultra-thin, low-depth-drawing aluminum alloy sheet for can bodies, characterized in that, The 3104 aluminum alloy ingot is subjected to homogenization treatment, hot rolling treatment and cold rolling treatment in sequence to obtain high-strength ultra-thin low-deep-drawing aluminum alloy sheet for can body. The homogenization process involves heating the 3104 aluminum alloy ingot to 450℃~610℃ at a heating rate of 100~120℃ / h and holding it at that temperature for 20~48h, followed by rapid cooling to the initial rolling temperature using strong air. The rolling speed of the hot rolling process is determined based on the size of the second phase particles.

5. The method for preparing high-strength, ultra-thin, low-depth-drawing aluminum alloy sheet for can bodies according to claim 4, characterized in that, During the homogenization process, the total cooling time and the holding time after cooling to the rolling temperature shall not exceed 2 hours; the rolling temperature is 430-510℃.

6. The method for preparing high-strength, ultra-thin, low-depth-drawing aluminum alloy sheet for can bodies according to claim 4, characterized in that, The hot rolling process includes hot roughing and hot finishing. The rolling temperatures of the last three passes of the hot finishing are controlled at 390–440°C, 360–410°C and 320–340°C, respectively, and the deformation amounts of the last three passes of the hot finishing are controlled at 50±5%, 45±5% and 45±5%, respectively.

7. The method for preparing high-strength, ultra-thin, low-depth-drawing aluminum alloy sheet for can bodies according to claim 4, characterized in that, During the hot rolling process, when the number density of particles larger than 1 μm in the second phase is <10 particles / μm 2 At that time, the rolling speed is 2-7 m / s; when the number density of particles larger than 1 μm in the second phase is ≥10 particles / μm 2 The rolling speed is controlled as follows: When the proportion of particles with an equivalent circular radius exceeding 5 μm exceeds 50%, the rolling speed is controlled according to the following formula: When the proportion of particles with an equivalent circular radius of 2–5 μm exceeds 50%, the rolling speed is controlled according to the following formula: When the proportion of particles with an equivalent circular radius < 1 μm exceeds 50%, the rolling speed is controlled according to the following formula: Where H and h are the plate thicknesses before and after the current rolling deformation, respectively, in meters; R is the gas constant, with a value of 8.314; T is the deformation temperature, in K; and R is the roll radius, in meters. The average radius of the second-phase particles is calculated based on the equivalent circle, in meters.

8. The method for preparing high-strength, ultra-thin, low-depth-drawing aluminum alloy sheet for can bodies according to claim 4, characterized in that, During the cold rolling process, the total cold rolling deformation is controlled at 75-90%, the deformation per pass is controlled at 40-60%, and the final rolling temperature is controlled at 150-165℃.

9. The method for preparing high-strength, ultra-thin, low-depth-drawing aluminum alloy sheet for can bodies according to any one of claims 4 to 8, characterized in that, The high-strength, ultra-thin, low-deep-drawing aluminum alloy sheet for the can body has an ear-making rate of ≤1.5%, a thickness of 0.240~0.260mm, a yield strength of 280~295MPa, and a tensile strength of 300~320MPa.

10. The method for preparing high-strength, ultra-thin, low-depth-drawing aluminum alloy sheet for can bodies according to any one of claims 4 to 8, characterized in that, The microstructure of the high-strength, ultra-thin, low-deep-drawing aluminum alloy sheet for can bodies includes a strong cubic texture and a cold-rolled deformation texture, wherein the content of the strong cubic texture is 10-12% and the content of the cold-rolled deformation texture is 88-90%.

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