5754 aluminum alloy coiled material and production method thereof

Abstract

The invention provides a 5754 aluminum alloy coiled material and a production method thereof. The production method comprises the following steps: carrying out hot rolling, cold rolling and heat treatment on a heated 5754 aluminum alloy cast ingot, wherein a roll type adopted for cold rolling is an original convexity roll type of + 0.10-0.12 mm; the cold rolling comprises three passes of rolling, the uncoiling tension of the first pass is 9-12 t, and the coiling tension of the first pass is 30-36 t; the uncoiling tension of the second pass is 28-36 t, and the coiling tension of the second pass is 30-36 t; and the uncoiling tension of the third pass is 24-28 t, and the coiling tension of the third pass is 16-24 t. By controlling the technological parameters of cold rolling, such as the original convexity, the pass setting and the tension setting of the roller shape, the geometric dimension precision of the finished 5754 aluminum alloy coiled material can be improved, the middle convexity is effectively reduced, the quality of the coiled material is more stable, the plate shape is more straight, and meanwhile the production efficiency is further improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of aluminum alloys, and particularly relates to a 5754 aluminum alloy coil and a production method thereof. Background Art

[0002] In recent years, with the development of technology, reducing the self-weight of automobiles and lowering fuel consumption have become the pursuit goals of automobile manufacturers. The main way to reduce the weight of automobiles is the lightweight of automobile materials. At present, as the main product of aluminum for automobile lightweight, the original production process of 5754 aluminum alloy coil is direct hot rolling, but there are problems such as large thickness tolerance, difficult control of plate shape, and unstable surface quality.

[0003] However, with the increasing degree of automation in the production of automobile parts, users' requirements for the plate shape and geometric dimensions of aluminum alloy coils are becoming more and more strict. Therefore, the hot-rolled aluminum alloy coils cannot meet the user's needs due to their disadvantages such as low dimensional accuracy, poor surface uniformity, and poor flatness of the plate shape. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a 5754 aluminum alloy coil and a production method thereof. The geometric dimension accuracy of the 5754 aluminum alloy coil obtained by this production method is improved, the plate shape is more flat, and the quality is more stable.

[0005] To achieve this purpose, the present invention adopts the following technical solutions:

[0006] In the first aspect, the present invention provides a production method of a 5754 aluminum alloy coil, including the following steps:

[0007] Hot rolling, cold rolling, and heat treatment are performed on the heated 5754 aluminum alloy ingot;

[0008] The roll profile used for cold rolling is a +0.10 - 0.12 mm original crown roll profile;

[0009] The cold rolling includes 3 passes of rolling. Among them, the uncoiling tension in the first pass is 9 - 12 t, and the coiling tension is 30 - 36 t; the uncoiling tension in the second pass is 28 - 36 t, and the coiling tension is 30 - 36 t; the uncoiling tension in the third pass is 24 - 28 t, and the coiling tension is 16 - 24 t.

[0010] Preferably, the roll profile is a +0.11 mm original crown roll profile.

[0011] Preferably, during the rolling process of the first pass, the roll gap is 5.55 ± 0.10 mm.

[0012] Preferably, during the rolling process of the second pass, the roll gap is 4.35 ± 0.10 mm.

[0013] Preferably, during the rolling process of the third pass, the roll gap is 3.72 ± 0.10 mm.

[0014] Preferably, the cross-section of the roll gap is rectangular.

[0015] Preferably, the reduction distribution for the three passes is as follows: from 8.0 ± 0.10 mm to 6.85 ± 0.10 mm; from 6.85 ± 0.10 mm to 5.70 ± 0.10 mm; from 5.70 ± 0.10 mm to 4.98 ± 0.10 mm.

[0016] The rolling speed of the first pass is 0.8 - 2 m / s, and the rolling force is 780 - 820 t; the rolling speed of the second pass is 1.5 - 2 m / s, and the rolling force is 815 - 830 t; the rolling speed of the third pass is 1 - 1.5 m / s, and the rolling force is 780 - 870 t.

[0017] Preferably, the reduction distribution for the three passes is as follows: from 8.0 ± 0.10 mm to 5.60 ± 0.10 mm; from 5.60 ± 0.10 mm to 4.70 ± 0.10 mm; from 4.70 ± 0.10 mm to 4.00 ± 0.10 mm;

[0018] The rolling speed of the first pass is 0.8 - 2 m / s, and the rolling force is 650 - 670 t; the rolling speed of the second pass is 1.5 - 2 m / s, and the rolling force is 680 - 700 t; the rolling speed of the third pass is 1 - 1.5 m / s, and the rolling force is 680 - 700 t.

[0019] Preferably, it is hot-rolled to a thickness of 8.0 ± 0.10 mm, and then cold-rolled and heat-treated.

[0020] Preferably, the heating temperature is 460 ± 10 °C.

[0021] Preferably, the hot rolling includes hot rough rolling and hot finish rolling.

[0022] Preferably, the heat treatment is carried out in a cushion furnace.

[0023] Preferably, the heat treatment temperature is 300 - 350 °C, and the speed is 3 - 6 m / min.

[0024] Preferably, a milling step is also included before heating.

[0025] Preferably, after cold rolling, it is recoiled and cleaned, and then heat-treated.

[0026] In a second aspect, the present invention provides a 5754 aluminum alloy coil obtained according to the above production method, wherein the convexity of the 5754 aluminum alloy coil is within 0.02 mm.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The present invention provides a method for producing 5754 aluminum alloy coils. This method utilizes a cold rolling process. By controlling the roll profile during the cold rolling process to a primary crown profile of +0.10 to 0.12 mm, the resulting coils can be effectively prevented from exhibiting edge or center waving, resulting in a more uniform surface and a straighter plate shape. Furthermore, the geometric dimensional accuracy of the finished 5754 aluminum alloy coils is significantly improved, the center crown is effectively controlled, and the thickness difference between the center and the sides is controlled within 0.02 mm, eliminating the problem of excessive center crown and ensuring stable stamping deformation for users. Furthermore, by controlling the tension in each of the three cold rolling passes, the present invention significantly reduces common sticking defects during coil production, significantly improving the surface quality and yield rate of the coils. Furthermore, the three-pass production method saves time and improves production efficiency compared to the five-pass production method commonly used in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is an appearance diagram of the finished 5754 aluminum alloy coil obtained in Example 1;

[0030] Figure 2 This is the appearance of the finished 5754 aluminum alloy coil obtained in Comparative Example 1;

[0031] Figure 3 This is the appearance of the finished 5754 aluminum alloy coil obtained in Comparative Example 2;

[0032] Figure 4 This is the appearance of the finished 5754 aluminum alloy coil obtained in Comparative Example 3. DETAILED DESCRIPTION

[0033] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0034] In view of the problems in the prior art that the 5754 aluminum alloy coil produced by the hot rolling process has disadvantages such as low dimensional accuracy, poor surface uniformity, and poor flatness of the sheet shape, and cannot meet the needs of users, the present invention provides a cold rolling production method for 5754 aluminum alloy coils, and the process route is: milling machine → heating furnace → hot rolling (i.e., hot rough rolling → hot finish rolling) → cold rolling → recoiling → cushion furnace → packaging.

[0035] In the present invention, the raw material used in the production method is a 5754 aluminum alloy ingot, and its composition only needs to meet the industry standard. In some embodiments of the present invention, the 5754 aluminum alloy ingot is provided by the melting and casting plant of Southwest Aluminum (Group) Co., Ltd.

[0036] The specifications of the 5754 aluminum alloy ingot can be designed according to the specifications of the finished 5754 aluminum alloy coil to be prepared, and there is no special limitation. In some embodiments of the present invention, the specifications of the 5754 aluminum alloy ingot are 510 mm × 1360 mm × 4500 mm.

[0037] In the present invention, the 5754 aluminum alloy ingot with specific specifications is first milled on the milling machine (milling the large and small surfaces) to mill off defects such as the oxide skin and coarse grain layer on the surface of the ingot, and the milling can be carried out according to the technical means well-known to those skilled in the art. In some embodiments of the present invention, the ingot is milled from 510 mm to 490 mm.

[0038] After the milling machine, according to the present invention, the milled 5754 aluminum alloy ingot is heated in a heating furnace to 440 - 480 °C and kept warm for 2 - 5 h, and preferably is taken out of the furnace after being kept warm at 460 °C for 3 h.

[0039] Then hot rolling treatment is carried out, and the hot rolling treatment includes hot rough rolling treatment and hot finish rolling treatment. In some embodiments of the present invention, the number of passes of the hot rough rolling is 25 - 35 passes, preferably 30 passes, the finishing pass temperature is 390 ± 20 °C, the number of passes of the hot finish rolling is 2 - 8 passes, preferably 3 passes, and the finishing pass temperature is 300 ± 20 °C.

[0040] The present invention preferably hot rolls to a blank thickness of 8.0 ± 0.10 mm, and then carries out cold rolling and heat treatment. This is beneficial to the regulation of the subsequent cold rolling process.

[0041] In the present invention, the cold rolling is carried out in a reversible cold rolling mill, preferably in a 2800 mm reversible four-high cold rolling mill, and the cold rolling processing of the metal strip is realized through the coordinated operation of multiple links such as uncoiling, rolling, and coiling.

[0042] During the cold rolling process, the shape of the roll gap determines the shape of the rolled coil. Ideally, the cross-section of the roll gap is rectangular during the rolling process, and the plastic deformation of the metal in the deformation zone of the rolled piece is uniform, which is conducive to rolling a coil with a flat shape. Generally, the working principle of a 2800mm reversible four-high cold rolling mill is as follows: Hydraulic cylinders on both sides of the rolling mill apply pressure to the upper backup roll, and the upper backup roll transfers the pressure to the upper work roll. The upper and lower work rolls are pressed against the upper and lower surfaces of the rolled piece to form a rolling roll gap, and the rotation of the upper and lower work rolls thins the rolled piece. However, during the pressing and rotational rolling process of the rolls of the cold rolling mill, elastic flattening and elastic bending (deflection) will occur to the rolls themselves. Therefore, in actual production, it is necessary to find a suitable original crown of the roll and the change in the roll gap caused by the bending deformation of the roll under force in the present invention.

[0043] During the experimental process of the present invention, rolls with original crown profiles of +0.07mm, +0.11mm, and +0.15mm were explored respectively. The results showed that when using the roll with an original crown profile of +0.07mm for rolling production, for the 5754 aluminum alloy of medium magnesium alloy with a deformation resistance far greater than that of the 1st, 3rd, and 6th series, it is necessary to adopt the method of reducing the reduction per pass and increasing the number of rolling passes to ensure good shape of the rolled coil. However, increasing the number of passes will increase the production cost, reduce the production efficiency, and increase the risk of layer shifting. At the same time, due to the small crown of the roll with an original crown profile of +0.07mm, it is unable to improve the influence of the large crown of the hot-rolled incoming sheet shape, resulting in the transverse thickness difference (i.e., the middle crown) of the coil exceeding the user's requirements, which affects the subsequent stamping deformation.

[0044] Specifically, in the present invention, the reduction distribution for cold rolling passes using the roll with an original crown profile of +0.07mm is: 8.0mm → 7.4mm → 6.7mm → 6.0mm → 5.45mm → 4.98mm, rolled in five passes, with a flat shape but a large transverse thickness difference (middle crown) and low production efficiency. However, if a three-pass rolling process is adopted: 8.0mm → 6.85mm → 5.70mm → 4.98mm, the reduction per pass increases, the contact area between the rolled piece and the roll increases, resulting in an increase in the rolling force. Using the roll with an original crown profile of +0.07mm cannot compensate for the bending of the roll caused by the increase in the reduction per pass, and a flat shape cannot be obtained, and edge waves will be generated (as Figure 2 shown).

[0045] For the roll with an original crown profile of +0.15mm used for rolling production, due to the excessive original crown, the middle part of the rolled coil extends more than the edges, resulting in middle waves (bulges), and it is not easy to flatten in the subsequent processes (as Figure 3As shown. Therefore, the present invention preferably uses a roll with an original crown roll profile of +0.11 mm for rolling production to ensure that the roll gap shape is straight during the rolling process, the cross-section of the rolled coil is rectangular, and the flatness is good, without edge waves or intermediate waves.

[0046] In the present invention, when the roll profile of the roll is preferably an original crown roll profile of +0.11 mm, three-pass rolling is adopted, and the rolling pass distribution is: 8.0 ± 0.10 mm → 6.85 ± 0.10 mm → 5.70 ± 0.10 mm → 4.98 ± 0.10 mm; or: 8.0 ± 0.10 mm → 5.60 ± 0.10 mm → 4.70 ± 0.10 mm → 4.00 ± 0.10 mm, and the flatness of the rolled coil better than that of the above-mentioned original crown roll profile of +0.07 mm with five-pass rolling and the flatness of the rolled coil with an original crown roll profile of +0.15 mm can be obtained.

[0047] In the present invention, for the processes of the above two pass distributions, during the rolling process of the first pass, the roll gap is preferably 5.55 ± 0.10 mm; during the rolling process of the second pass, the roll gap is preferably 4.35 ± 0.10 mm; during the rolling process of the third pass, the roll gap is preferably 3.72 ± 0.10 mm.

[0048] In the present invention, the rolling speed during the cold rolling process is 0.8 - 2 m / s and the rolling force is 780 - 870 tons (abbreviation: t), and it needs to match the reduction per pass. It should be noted that the faster the rolling speed, the faster the roll temperature rises. Since the middle of the roll body dissipates heat slower than the edges, the temperature in the middle of the roll body is higher, so that the roll crown increases and the roll profile increases, and intermediate waves are likely to occur; at the same speed, when the rolling force increases, the elastic bending of the roll increases, the roll deflection increases, and edge waves are likely to occur. Therefore, the present invention preferably controls the cold rolling within the above rolling speed and rolling force.

[0049] Therefore, preferably in the present invention, for the process with pass distribution of 8.0±0.10mm→6.85±0.10mm→5.70±0.10mm→4.98±0.10mm, the rolling speed in the first pass is 0.8 to 2 m / s, such as 0.8 m / s, 1.0 m / s, 1.2 m / s, 1.5 m / s, 1.8 m / s or 2 m / s, etc., and the rolling force is 780 to 820 t, such as 780 t, 790 t, 800 t, 810 t or 820 t, etc.; the rolling speed in the second pass is 1.5 to 2 m / s, such as 1.5 m / s, 1.6 m / s, 1.7 m / s, 1.8 m / s, 1.9 m / s or 2 m / s, etc., and the rolling force is 815 to 830 t, such as 815 t, 820 t, 825 t or 830 t, etc.; the rolling speed in the third pass is 1 to 1.5 m / s, such as 1 m / s, 1.1 m / s, 1.2 m / s, 1.3 m / s, 1.4 m / s or 1.5 m / s, etc., and the rolling force is 780 to 870 t, such as 780 t, 790 t, 800 t, 810 t, 820 t, 830 t, 840 t, 850 t, 860 t or 870 t, etc.

[0050] For the process with pass distribution of 8.0±0.10mm→5.60±0.10mm→4.70±0.10mm→4.00±0.10mm, the rolling speed in the first pass is 0.8 to 2 m / s, such as 0.8 m / s, 1.0 m / s, 1.2 m / s, 1.5 m / s, 1.8 m / s or 2 m / s, etc.; the rolling force is 650 to 670 t, such as 650 t, 655 t, 660 t, 665 t or 670 t, etc.; the rolling speed in the second pass is 1.5 to 2 m / s, such as 1 m / s, 1.1 m / s, 1.2 m / s, 1.3 m / s, 1.4 m / s or 1.5 m / s, etc., and the rolling force is 680 to 700 t, such as 680 t, 685 t, 690 t, 695 t or 700 t, etc.; the rolling speed in the third pass is 1 to 1.5 m / s, such as 1 m / s, 1.1 m / s, 1.2 m / s, 1.3 m / s, 1.4 m / s or 1.5 m / s, etc., and the rolling force is 680 to 700 t, such as 680 t, 685 t, 690 t, 695 t or 700 t, etc.

[0051] The above point values are only for listing, and other point values within the numerical range are applicable. To avoid complexity, they will not be elaborated one by one here.

[0052] In the present invention, the cold rolling is carried out in a reversible rolling mill, and a front coiler and a rear coiler are arranged at the front and rear of the reversible rolling mill. In the present invention, the rolling directions in the cold rolling process of 3 passes can be as follows: in the first pass, from left to right; in the second pass, from right to left; in the third pass, from left to right;

[0053] Or

[0054] In the first pass, from right to left; in the second pass, from left to right; in the third pass, from right to left.

[0055] However, regardless of the rolling direction as described above, each pass needs to go through the steps of: uncoiling - rolling - coiling.

[0056] Exemplarily, in the first pass, from left to right, the uncoiling - rolling - coiling of the front coiler are carried out in sequence; in the second pass, from right to left, the uncoiling - rolling - coiling of the rear coiler are carried out in sequence; in the third pass, repeat the first pass, that is, the uncoiling - rolling - coiling of the front coiler are carried out in sequence.

[0057] Among them, both uncoiling and coiling involve the setting of the magnitude of the tension. In the actual production of the present invention, according to the quality feedback of the subsequent process, it is found that when the 5754 aluminum alloy coil is uncoiled in the subsequent process, interlayer adhesion defects often occur, and serious adhesion will directly cause scrapping. After analysis in the present invention, it is found that the main reason for the adhesion is that during the production of the 5754 aluminum alloy coil, the rolling speed is relatively fast and the heat generation is large. Under the condition of large tension, the interlayer pressure of the coil increases, resulting in surface adhesion and causing adhesion, as Figure 4 shown. Therefore, appropriately reducing the tension (mainly reducing the tension in the final pass, that is, the coiling tension in the third pass) is beneficial to eliminating the surface adhesion.

[0058] Therefore, preferably in the present invention, during the cold rolling process of 3 passes, the uncoiling tension in the first pass is 9 - 12t, such as 9t, 9.5t, 10t, 10.5t, 11t, 11.5t or 12t, etc., and the coiling tension is 30 - 36t, such as 30t, 31t, 32t, 33t, 34t, 35t or 36t, etc.; the uncoiling tension in the second pass is 28 - 36t, such as 28t, 30t, 32t, 34t or 36t, etc., and the coiling tension is 30 - 36t, such as 30t, 31t, 32t, 33t, 34t, 35t or 36t, etc.; the uncoiling tension in the third pass is 24 - 28t, such as 24t, 24.5t, 25t, 25.5t, 26t, 26.5t, 27t, 27.5t or 28t, etc., and the coiling tension is 16 - 24t, such as 16t, 17t, 18t, 19t, 20t, 21t, 22t, 23t or 24t, etc.

[0059] The above point values are only for enumeration. Other point values within the numerical range are applicable. To avoid complexity, they will not be listed here one by one.

[0060] The present invention uses the above-mentioned tension setting to produce coils with good plate shape. Through continuous tracking of the quality feedback of the subsequent process, it is found that the sticking defect is greatly reduced, and the sticking problem is effectively solved.

[0061] After the cold rolling is completed, according to the present invention, the obtained coil is handed over to the rewinder to clean the surface oil stains and then subjected to heat treatment, which is preferably carried out in an air cushion furnace; the heat treatment temperature is 300-350°C, such as 300, 310, 320, 330, 340 or 350°C; the speed is 3-6 m / min, such as 3 m / min, 4 m / min, 5 m / min or 6 m / min.

[0062] In the present invention, after the heat treatment is completed, the coiled material is packaged and shipped out of the factory.

[0063] As needed, the coiled material can be cut to length to obtain the corresponding sheet material.

[0064] The present invention tests the 5754 aluminum alloy coil obtained according to the above production method and finds that the convexity of the 5754 aluminum alloy coil is within 0.02 mm.

[0065] The present invention does not impose any particular limitation on the length, width and thickness of the coil, which can be designed as required.

[0066] In summary, the present invention provides an excellent cold rolling production method for 5754 aluminum alloy coil, which has the following advantages:

[0067] (1) The geometric dimensional accuracy of the coil is significantly improved, the convexity is effectively controlled, and the thickness difference between the middle and the two sides is controlled within 0.02mm, eliminating the phenomenon of excessive convexity in the coil and ensuring stable stamping deformation for users.

[0068] (2) The coil shape is straighter. After the roller profile is adjusted to +0.11mm original crown, the cross section of the roll gap during rolling becomes closer to a rectangle, ensuring more uniform metal flow across the entire cross section, reducing edge waves, and making the finished coil shape straighter.

[0069] (3) Production efficiency is significantly improved. After the innovative cold rolling process, the number of cold rolling passes was reduced from 5 to 3, saving 8 to 10 minutes per coil, and significantly improving production efficiency.

[0070] (4) More stable quality. Common sticking defects are greatly reduced, and the surface quality and yield rate of the coil are greatly improved.

[0071] To further illustrate the present invention, the following examples are provided. The 5754 aluminum alloy ingots used in the following examples of the present invention have a size of 510×1360×4500 mm and are provided by the Southwest Aluminum (Group) Co., Ltd. Foundry. The composition of the 5754 aluminum alloy ingots meets industry standards.

[0072] Example 1

[0073] This embodiment provides a production method for 5754 aluminum alloy coils, wherein the process route is: milling machine → heating furnace → hot rough rolling → hot finish rolling → cold rolling → recoiling → air cushion furnace → packaging. The specific steps are as follows:

[0074] The 5754 aluminum alloy ingot is milled on a milling machine (the thickness is reduced from 510mm to 490mm), then heated to 460℃ in a heating furnace and taken out of the furnace after insulation. It is hot rough rolled through 30 passes to a hot finishing rough material thickness of 22mm (final rolling temperature ≥350℃), and then transported to the finishing mill through a roller table. The finishing mill is rolled through 3 passes to a thickness of 8.0mm±0.1mm (final rolling temperature ≥300℃). After the temperature is cooled to below 60℃, the coil is rolled to a thickness of 4.98mm in three passes on a cold rolling mill (with a roll profile of +0.11mm original crown). The coil is then re-rolled to clean the surface oil and dirt, and heat-treated in an air cushion furnace (at a temperature of 330℃ and a speed of 4m / min). The coil is then packaged and shipped. The specifications of the finished 5754 aluminum alloy coil are 4.98 (thickness) × 1258 (width) × C mm, where C is the abbreviation of Coil, representing the delivery of the finished coil. The length is not specifically limited and can be designed according to subsequent needs.

[0075] The cold rolling parameters are shown in Table 2 below:

[0076] Table 2

[0077] Pass Thickness / mm Roll Gap / mm Coiling Tension / t Uncoiling Tension / t Speed / (m / s) Rolling Force / t Crown / mm 1 6.85 5.55 35.4 9 0.8 795 - 2 5.8 4.45 33.2 35.3 2 828 - 3 4.98 3.5 23.1 26.6 1 870 +0.02

[0078] The appearance of the finished 5754 aluminum alloy coil obtained in this embodiment is shown in FIG. Figure 1 As shown, the production method of the present invention achieves a flatter finished coil, significantly reducing surface sticking defects, significantly improving the surface quality and yield rate of the coil. Furthermore, the finished coil exhibits a center crown of +0.02mm, indicating that the thickness difference between the center and sides of the coil is within 0.02mm, eliminating excessive center crown and ensuring stable deformation during subsequent stamping.

[0079] Example 2

[0080] This embodiment provides a production method for 5754 aluminum alloy coils. Compared with Example 1, the only difference is the cold rolling parameters, and the other parameters and steps remain the same. The cold rolling parameters are shown in Table 3 below:

[0081] Table 3

[0082] Pass Thickness / mm Roll Gap / mm Coiling Tension / t Uncoiling Tension / t Speed / (m / s) Rolling Force / t Crown / mm 1 6.85 5.48 35.4 9 1.5 800 - 2 5.7 4.30 35 35 2 826 - 3 4.98 3.75 22 24 1 780 +0.02

[0083] The specifications of the finished coil are 4.98×1258×C mm.

[0084] The finished coil has a straight plate shape, surface adhesion defects are greatly reduced, and the surface quality and yield rate of the coil are greatly improved.

[0085] Example 3

[0086] This embodiment provides a production method for 5754 aluminum alloy coils. Compared with Example 1, the only difference is the cold rolling parameters, and the other parameters and steps remain the same. The cold rolling parameters are shown in Table 4 below:

[0087] Table 4

[0088] Pass Thickness / mm Roll Gap / mm Coiling Tension / t Uncoiling Tension / t Speed / (m / s) Rolling Force / t Crown / mm 1 6.85 5.50 35 9 1.5 810 - 2 5.7 4.30 35.4 35.4 2 820 - 3 4.98 3.72 22 26 1 780 +0.02

[0089] The specifications of the finished coil are 4.98×1258×C mm.

[0090] The finished coil has a straight plate shape, surface adhesion defects are greatly reduced, and the surface quality and yield rate of the coil are greatly improved.

[0091] Example 4

[0092] This embodiment provides a method for producing a 5754 aluminum alloy coil. Compared with Example 1, the only difference is the cold rolling parameters, and the other parameters and steps remain the same. The cold rolling parameters are shown in Table 5 below:

[0093] Table 5

[0094] Pass Thickness / mm Roll Gap / mm Coiling Tension / t Uncoiling Tension / t Speed / (m / s) Rolling Force / t Crown / mm 1 5.6 4.7 31 9 1.5 670 - 2 4.7 3.7 30 28 2 696 - 3 4.0 3.1 17 26 1.2 690 +0.02

[0095] The specifications of the finished coil are 4.00×1200×C mm.

[0096] The finished coil has a straight plate shape, surface adhesion defects are greatly reduced, and the surface quality and yield rate of the coil are greatly improved.

[0097] Example 5

[0098] Compared with Example 1, the only difference is that the roller profile of the cold rolling mill is a +0.10mm original crown roller profile, and the other parameters and steps are consistent with Example 1.

[0099] Example 6

[0100] Compared with Example 1, the only difference is that the roll profile of the cold rolling mill is a +0.12 mm original crown roll profile, and the other parameters and steps are the same as those in Example 1.

[0101] Comparative Example 1

[0102] Compared with Example 1, the difference is that the roll profile of the cold rolling mill is a +0.07 mm original crown roll profile, and the parameters of the cold rolling are shown in Table 6 below:

[0103] Table 6

[0104] Pass Thickness / mm Roll Gap / mm Coiling Tension / t Uncoiling Tension / t Speed / (m / s) Rolling Force / t Crown / mm 1 7.3 6.5 35 35 1.5 630 - 2 6.7 5.9 35 35 2 650 - 3 6 5.2 35 35 2 650 - 4 5.45 4.7 35 35 2 650 - 5 4.98 4.2 30 33 1 600 0.045

[0105] The other parameters and steps are the same as those in Example 1.

[0106] The appearance diagram of the finished 5754 aluminum alloy coil obtained in this comparative example is as Figure 2 shown, and there are edge waves. Combining with Table 5, it can be seen that when using a +0.07 mm original crown roll profile for 5 passes of production, the crown of the obtained coil is relatively large, and the middle is about 0.05 mm thicker than both sides.

[0107] From the comparison between Example 1 and Comparative Example 1, it can be seen that when producing 5754 aluminum alloy coils with a +0.07 mm original crown roll profile, 5 passes of rolling are required to complete, and there are often edge waves. The crown of the cold-rolled finished aluminum alloy coil reaches +0.05 mm. While for the same specification of 5754 aluminum alloy coil produced with a +0.11 mm original crown roll profile, it only needs 3 passes to roll to the finished thickness, and the production time of each roll is shortened by 8 - 10 minutes, significantly improving the production efficiency. Moreover, the shape of the coil is excellent, the middle crown is +0.02 mm, and the control level of the middle crown is significantly improved, solving the contradiction between production supply and user needs.

[0108] Comparative Example 2

[0109] Compared with Example 1, the only difference is that the roll profile of the cold rolling mill is a +0.15 mm original crown roll profile, and the other parameters and steps are the same as those in Example 1.

[0110] The appearance diagram of the finished 5754 aluminum alloy coil obtained in this comparative example is as Figure 3 shown. It can be seen that due to the excessive original crown, the middle part of the coil extends more than the edge part, resulting in middle waves (bulges), and it is not easy to flatten in the subsequent processes.

[0111] Comparative Example 3

[0112] Compared with Example 1, the only difference is that during the cold rolling process, the uncoiling tension in the first pass is 15t and the coiling tension is 40t; the uncoiling tension in the second pass is 40t and the coiling tension is 40t; the uncoiling tension in the third pass is 33t and the coiling tension is 30t; the remaining parameters and steps are the same as those in Example 1.

[0113] The appearance diagram of the finished 5754 aluminum alloy coil obtained in this comparative example is as Figure 4 shown. It can be seen that due to the relatively large coiling tension in the finishing pass, sticking defects will be caused on the surface of the produced coil (i.e., Figure 4 the points indicated by the arrows in).

[0114] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A production method of 5754 aluminum alloy coil, characterized in that, It includes the following steps: Hot-rolling, cold-rolling and heat treatment are carried out on the heated 5754 aluminum alloy ingot; The roll profile used for the cold rolling is an original crown roll profile of +0.10 to 0.12 mm; The cold rolling includes 3 passes of rolling. Among them, the uncoiling tension in the first pass is 9 to 12 t, and the coiling tension is 30 to 36 t; the uncoiling tension in the second pass is 28 to 36 t, and the coiling tension is 30 to 36 t; the uncoiling tension in the third pass is 24 to 28 t, and the coiling tension is 16 to 24 t.

2. The production method according to claim 1, characterized in that, The roll profile is an original crown roll profile of +0.11 mm.

3. The production method according to claim 1 or 2, characterized in that, During the rolling process of the first pass, the roll gap is 5.55 ± 0.10 mm; During the rolling process of the second pass, the roll gap is 4.35 ± 0.10 mm; During the rolling process of the third pass, the roll gap is 3.72 ± 0.10 mm; The cross-section of the roll gap is rectangular.

4. The production method according to any one of claims 1 to 3, characterized in that, The reduction distribution of the 3 passes is: from 8.0 ± 0.10 mm to 6.85 ± 0.10 mm; from 6.85 ± 0.10 mm to 5.70 ± 0.10 mm; from 5.70 ± 0.10 mm to 4.98 ± 0.10 mm; The rolling speed of the first pass is 0.8 to 2 m / s, and the rolling force is 780 to 820 t; the rolling speed of the second pass is 1.5 to 2 m / s, and the rolling force is 815 to 830 t; the rolling speed of the third pass is 1 to 1.5 m / s, and the rolling force is 780 to 870 t.

5. The production method according to any one of claims 1 to 4, characterized in that, The reduction distribution of the 3 passes is: from 8.0 ± 0.10 mm to 5.60 ± 0.10 mm; from 5.60 ± 0.10 mm to 4.70 ± 0.10 mm; from 4.70 ± 0.10 mm to 4.00 ± 0.10 mm; The rolling speed of the first pass is 0.8 to 2 m / s, and the rolling force is 650 to 670 t; the rolling speed of the second pass is 1.5 to 2 m / s, and the rolling force is 680 to 700 t; the rolling speed of the third pass is 1 to 1.5 m / s, and the rolling force is 680 to 700 t.

6. The production method according to any one of claims 1 to 5, characterized in that, Hot-roll to a thickness of 8.0 ± 0.10 mm, and then carry out cold rolling and heat treatment.

7. The production method according to any one of claims 1 to 6, characterized in that, The heating temperature is 460 ± 10 °C; The hot rolling includes hot rough rolling and hot finish rolling.

8. The production method according to any one of claims 1 to 7, characterized in that, The heat treatment is carried out in a cushion furnace; The temperature of the heat treatment is 300 to 350 °C, and the speed is 3 to 6 m / min.

9. The production method according to any one of claims 1 to 8, characterized in that, Before heating, it also includes the step of milling; After cold rolling, it is recoiled and cleaned, and then heat treatment is carried out. The 5754 aluminum alloy coil produced by the production method according to any one of claims 1 to 9, characterized in that, The mid-crown of the 5754 aluminum alloy coil is within 0.02 mm.

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