Straightness control method for hot rolling waste heat online quenching aluminum alloy thick plate

Abstract

The invention discloses a straightness control method for a hot rolling waste heat online quenched aluminum alloy thick plate, relates to the field of aluminum alloy manufacturing, and can solve the problems that the straightness of the quenched aluminum alloy thick plate is poor, the plate shape cannot be effectively improved by means of traditional roller type leveling, and the production efficiency is low. The method comprises the following procedures of waste heat online quenching, flattening rolling, plate shearing and plate stretching, specifically, by controlling the quenching water pressure and the upper and lower water pressure difference during online quenching of the aluminum alloy thick plate, flattening rolling is conducted through a hot rolling mill after quenching, the sheared plate is subjected to stretching machining, and the aluminum alloy thick plate with the transverse and longitudinal unevenness smaller than or equal to 2.5 mm can be produced; and the production efficiency is high.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum alloys, and in particular to a method for controlling the flatness of an aluminum alloy thick plate subjected to online quenching by hot rolling residual heat. Background Art

[0002] Aluminum alloy has the characteristics of low density and good electrical and thermal conductivity. Heat treatment can strengthen the aluminum alloy thick plate. The strength is greatly improved after solid solution and aging heat treatment. It is widely used in machinery manufacturing, molds, transportation and other industries.

[0003] Straightness is an important quality indicator of aluminum alloy plates, which affects the processing efficiency, whether the processing allowance is sufficient and the final product quality during subsequent processing. Users hope to obtain plates with good straightness. Compared with the conventional production method of re-solutionizing and quenching the plates after hot rolling, online quenching with residual heat from hot rolling is more prone to lateral warping and waves after quenching due to the relatively greater temperature non-uniformity before quenching. For heat-treated aluminum alloy thick plates, the straightness problem is caused by the residual stress generated by the rolling and quenching processes, which needs to be controlled during the quenching process and the residual stress eliminated in the subsequent finishing process.

[0004] There are two main types of flatness defects in thick aluminum alloy plates: transverse warping caused by the length difference between the upper and lower surfaces, and waves caused by the length difference in the width direction. At present, the problem of transverse warping is mainly improved by straightening the plates with roller straighteners. This production method requires single-piece production and the straightener runs slowly, resulting in low production efficiency. When the plate shape is too poor, roller straightening cannot effectively straighten it, and the wave problem is mainly eliminated by stretching. Summary of the invention

[0005] In view of the above shortcomings, the present invention provides a method for controlling the flatness of an aluminum alloy thick plate quenched online by hot rolling residual heat, which can make the transverse and longitudinal unevenness of the aluminum alloy thick plate ≤2.5mm through the reasonable matching of the upper and lower water pressure difference in the online quenching high-pressure zone, the leveling rolling after quenching, and the plate stretching. The specific technical scheme is as follows:

[0006] The present invention provides a method for controlling the flatness of a thick aluminum alloy plate by online quenching with residual heat from hot rolling, comprising: online quenching with residual heat, temper rolling, plate shearing, and stretching, specifically comprising the following steps:

[0007] S1, residual heat online quenching, transferring the high-temperature aluminum alloy thick plate in the solid solution state after solution heating and hot rolling to the roller quenching zone of the hot rolling mill for cooling and quenching to obtain the quenched aluminum alloy thick plate; the residual heat online quenching process parameters are: controlling the quenching water pressure according to the plate thickness, specifically:

[0008] The quenching water pressure for plates with a thickness of 15 mm or less and ≤ 55 mm is 2.6 to 3.4 bar, and the water pressure at the upper end is 0.2 to 0.4 bar higher than the water pressure at the lower end;

[0009] The quenching water pressure for plates with a thickness of 55mm and a thickness of ≤85mm is 3.2 to 3.8 bar and the difference between the upper and lower water pressures is -0.1 to 0.1 bar;

[0010] The quenching water pressure for plates with a thickness of 85mm<≤150mm is 3.8~4.5bar and the difference between the upper and lower water pressures is -0.1~0.1bar;

[0011] S2, temper rolling, temper rolling the aluminum alloy thick plate after quenching in step S1 to obtain a temper rolled aluminum alloy thick plate;

[0012] S3, plate shearing, shearing the aluminum alloy thick plate smooth rolled in step S2 to obtain a sheared aluminum alloy thick plate;

[0013] S4, stretching, stretching the aluminum alloy thick plate sheared in step S3.

[0014] Furthermore, the waste heat online quenching process parameters are:

[0015] The quenching water pressure for plates with a thickness of 15 mm or less and ≤ 55 mm is 2.8 to 3.2 bar, and the water pressure at the upper end is 0.2 to 0.3 bar higher than that at the lower end;

[0016] The quenching water pressure for plates with a thickness of 55mm<≤85mm is 3.4~3.6bar and the difference between the upper and lower water pressures is -0.1~0.1bar;

[0017] The quenching water pressure for plates with a thickness of 85mm<≤150mm is 3.9~4.3bar and the difference between the upper and lower water pressures is -0.1~0.1bar.

[0018] Furthermore, in the flat rolling process, the rolling force is 200 to 400 tons.

[0019] Furthermore, in the flat rolling process, the working roll bending force is -120 to 120 tons.

[0020] Furthermore, in the temper rolling process, the temper rolling speed is 40 to 80 m / min.

[0021] Furthermore, in the stretching process, a plate stretching machine is used to stretch the aluminum alloy thick plate, and the stretching elongation is 1.8-2.7%.

[0022] Furthermore, the thickness of the high-temperature aluminum alloy thick plate in a solid solution state after solid solution heating and hot rolling is 20 to 150 mm.

[0023] Furthermore, the transverse and longitudinal unevenness of the aluminum alloy thick plate is ≤2.5 mm.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The present invention provides a method for controlling the flatness of an aluminum alloy thick plate by online quenching with residual heat from hot rolling. After online quenching water pressure control, post-quenching leveling rolling and stretching, the aluminum alloy thick plate has high flatness, and the transverse and longitudinal unevenness is ≤2.5mm.

[0026] 2. When aluminum alloy thick plates are quenched, internal stress is inevitably generated due to uneven cooling due to the fast cooling speed. When the internal stress is too large, it will cause uneven deformation in the thickness, length and width directions, forming plate defects such as lateral warping and waves. The present invention can improve the cooling uniformity of the upper and lower surfaces and reduce the lateral warping formed during quenching by reasonably controlling the upper and lower cooling water pressures during quenching. After quenching, flat rolling with a small reduction can eliminate some of the internal stress and uneven deformation generated during quenching, and improve the lateral and longitudinal straightness of the thick plate. Stretching the plate can effectively eliminate the internal stress of the plate and improve the longitudinal straightness of the plate. Therefore, by reasonably controlling the online quenching water pressure and performing flat rolling and stretching after quenching, aluminum alloy hot-rolled thick plates with good flatness can be produced.

[0027] 3. The conventional straightening process requires that the plate be cut into shorter single pieces first, and then transported to a roller straightening machine for single piece straightening. When the plate shape is too poor, roller straightening cannot effectively straighten. Compared with the conventional roller straightening process, the present invention utilizes the residual heat after hot rolling to directly flatten the long plate after hot rolling on a hot rolling mill at one time. The three processes of hot rolling, online quenching, and flattening are integrated in the hot rolling production line for continuous processing. First, the flattening rolling speed is faster than the plate straightening speed. Second, the stacking and transportation of plates are reduced. The overall speed can be increased by more than 3 times, and the production efficiency is higher. DETAILED DESCRIPTION

[0028] The specific embodiments of the present invention are described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0029] Example 1

[0030] A method for controlling the flatness of a thick aluminum alloy plate subjected to online quenching by residual heat of hot rolling in this embodiment comprises the following steps: online quenching by residual heat → temper rolling → plate shearing → stretching, and the specific steps include:

[0031] (1) Residual heat online quenching: The 6061 aluminum alloy plate with a thickness of 30.5 mm and a width of 1600 mm in the solid solution state after solution heating or hot rolling is transferred to the roller quenching zone of the hot rolling mill for cooling and quenching. The water pressure at the upper end of the quenching zone is 2.8 bar and the water pressure at the lower end is 2.6 bar to obtain the quenched aluminum alloy plate.

[0032] (2) Tempering: The quenched plate is tempered with a rolling force of 200 tons, a working roll bending force of 30 tons, and a tempering speed of 80 m / min to obtain a tempered plate.

[0033] (3) Sheet shearing: Shearing the flat rolled sheet to obtain a sheared sheet;

[0034] (4) Stretching: The sheared sheet was stretched using a sheet stretching machine, with a stretching elongation of 2.7%.

[0035] After the above processing, the plate obtained in this embodiment has a transverse unevenness of 1.7 mm and a longitudinal unevenness of 2.0 mm.

[0036] Example 2

[0037] A method for controlling the flatness of a thick aluminum alloy plate subjected to online quenching by residual heat of hot rolling in this embodiment comprises the following steps: online quenching by residual heat → temper rolling → plate shearing → stretching, and the specific steps include:

[0038] (1) Residual heat online quenching: The 6061 aluminum alloy plate with a thickness of 131.9 mm and a width of 1750 mm in the solid solution state after solution heating or hot rolling is transferred to the roller quenching zone of the hot rolling mill for cooling and quenching. The water pressure at the upper end of the quenching zone is 4.2 bar and the water pressure at the lower end is 4.1 bar to obtain the quenched aluminum alloy plate.

[0039] (2) Temper rolling: The quenched plate is tempered with a rolling force of 400 tons, a working roll bending roll of 120 tons, and a tempering speed of 60 m / min to obtain a tempered plate.

[0040] (3) Plate shearing: Shearing the flat rolled plate to obtain a sheared plate.

[0041] (4) Stretching: The sheared sheet was stretched using a sheet stretching machine, with a stretching elongation of 1.8%.

[0042] After the above processing, the plate obtained in this embodiment has a transverse unevenness of 1.2 mm and a longitudinal unevenness of 1.5 mm.

[0043] Example 3

[0044] A method for controlling the flatness of a thick aluminum alloy plate subjected to online quenching by residual heat of hot rolling in this embodiment comprises the following steps: online quenching by residual heat → temper rolling → plate shearing → stretching, and the specific steps include:

[0045] (1) Residual heat online quenching: The 6061 aluminum alloy plate with a thickness of 76.1 mm and a width of 2100 mm in the solid solution state after solution heating or hot rolling is transferred to the roller quenching zone of the hot rolling mill for cooling and quenching. The water pressure at the upper end of the quenching zone is 3.4 bar and the water pressure at the lower end is 3.5 bar to obtain the quenched aluminum alloy plate.

[0046] (2) Tempering: The quenched plate is tempered with a rolling force of 300 tons, a working roll bending roll of -120 tons, and a tempering speed of 40 m / min to obtain a tempered plate.

[0047] (3) Plate shearing: Shearing the flat rolled plate to obtain a sheared plate.

[0048] (4) Stretching: The sheared sheet was stretched using a sheet stretching machine, with a stretching elongation of 2.2%.

[0049] After the above processing, the plate obtained in this embodiment has a transverse unevenness of 1.0 mm and a longitudinal unevenness of 1.3 mm.

[0050] Comparative Example 1

[0051] The present comparative example provides a method for controlling the flatness of a hot-rolled residual heat online quenching aluminum alloy thick plate, comprising the following steps: residual heat online quenching → leveling rolling → plate shearing → stretching, and the specific steps include:

[0052] (1) Residual heat online quenching: The 6061 aluminum alloy plate with a thickness of 30.5 mm and a width of 1600 mm in the solid solution state after solution heating or hot rolling is transferred to the roller quenching zone of the hot rolling mill for cooling and quenching. The water pressure at the upper end of the quenching zone is 3.6 bar and the water pressure at the lower end is 3.8 bar to obtain the quenched aluminum alloy plate.

[0053] (2) Temper rolling: The quenched plate is tempered with a rolling force of 200 tons, a working roll bending force of 30 tons, and a tempering speed of 80 m / min to obtain a tempered plate.

[0054] (3) Plate shearing: Shearing the flat rolled plate to obtain a sheared plate.

[0055] (4) Stretching: The sheared sheet was stretched using a sheet stretching machine, with a stretching elongation of 2.7%.

[0056] Compared with Example 1, the water pressure in the quenching zone is increased and the water pressure difference between the upper and lower ends is adjusted from 0.2 bar to -0.2 bar. After the above processing, the obtained plate has a transverse unevenness of 4.8 mm and a longitudinal unevenness of 3.5 mm.

[0057] Comparative Example 2

[0058] The present comparative example provides a method for controlling the flatness of a hot-rolled residual heat online quenching aluminum alloy thick plate, comprising the following steps: residual heat online quenching → leveling rolling → plate shearing → stretching, and the specific steps include:

[0059] (1) Residual heat online quenching: The 6061 aluminum alloy plate with a thickness of 30.5 mm and a width of 1600 mm in the solid solution state after solution heating or hot rolling is transferred to the roller quenching zone of the hot rolling mill for cooling and quenching. The water pressure at the upper end of the quenching zone is 2.3 bar and the water pressure at the lower end is 2.5 bar to obtain the quenched aluminum alloy plate.

[0060] (2) Temper rolling: The quenched plate is tempered with a rolling force of 200 tons, a working roll bending force of 30 tons, and a tempering speed of 80 m / min to obtain a tempered plate.

[0061] (3) Plate shearing: Shearing the flat rolled plate to obtain a sheared plate.

[0062] (4) Stretching: The sheared sheet was stretched using a sheet stretching machine, with a stretching elongation of 2.7%.

[0063] Compared with Example 1, the water pressure in the quenching zone of Comparative Example 2 is reduced and the water pressure difference between the upper and lower ends is adjusted from 0.2 bar to -0.2 bar. After the above processing, the obtained plate has a transverse unevenness of 5.0 mm and a longitudinal unevenness of 3.3 mm.

[0064] Comparative Example 3

[0065] The present comparative example provides a method for controlling the flatness of a hot-rolled residual heat online quenching aluminum alloy thick plate, comprising the following steps: residual heat online quenching → leveling rolling → plate shearing → stretching, and the specific steps include:

[0066] (1) Residual heat online quenching: The 6061 aluminum alloy plate with a thickness of 131.9 mm and a width of 1750 mm in the solid solution state after solution heating or hot rolling is transferred to the roller quenching zone of the hot rolling mill for cooling and quenching. The water pressure at the upper end of the quenching zone is 4.6 bar and the water pressure at the lower end is 4.8 bar to obtain the quenched aluminum alloy plate.

[0067] (2) Temper rolling: The quenched plate is tempered with a rolling force of 300 tons, a working roll bending roll of -120 tons, and a tempering speed of 40 m / min to obtain a tempered plate.

[0068] (3) Plate shearing: Shearing the flat rolled plate to obtain a sheared plate.

[0069] (4) Stretching: The sheared sheet was stretched using a sheet stretching machine, with a stretching elongation of 1.8%.

[0070] Compared with Example 2, the water pressure in the quenching zone is increased and the water pressure difference between the upper and lower ends is adjusted from 0.1 bar to -0.2 bar. After the above processing, the obtained plate has a transverse unevenness of 3.5 mm and a longitudinal unevenness of 2.9 mm.

[0071] Comparative Example 4

[0072] The present comparative example provides a method for controlling the flatness of a hot-rolled residual heat online quenching aluminum alloy thick plate, comprising the following steps: residual heat online quenching → leveling rolling → plate shearing → stretching, and the specific steps include:

[0073] (1) Residual heat online quenching: The 6061 aluminum alloy plate with a thickness of 131.9 mm and a width of 1750 mm in the solid solution state after solution heating or hot rolling is transferred to the roller quenching zone of the hot rolling mill for cooling and quenching. The water pressure at the upper end of the quenching zone is 3.5 bar and the water pressure at the lower end is 3.7 bar to obtain the quenched aluminum alloy plate.

[0074] (2) Temper rolling: The quenched plate is tempered with a rolling force of 400 tons, a working roll bending roll of 120 tons, and a tempering speed of 60 m / min to obtain a tempered plate.

[0075] (3) Plate shearing: Shearing the flat rolled plate to obtain a sheared plate.

[0076] (4) Stretching: The sheared sheet was stretched using a sheet stretching machine, with a stretching elongation of 1.8%.

[0077] Compared with Example 2, the water pressure in the quenching zone is reduced in this comparative example, and the water pressure difference between the upper and lower ends is adjusted from 0.1 bar to -0.2 bar. After the above processing, the obtained plate has a transverse unevenness of 4.0 mm and a longitudinal unevenness of 2.8 mm.

[0078] Comparative Example 5

[0079] The present comparative example provides a method for controlling the flatness of a hot-rolled residual heat online quenching aluminum alloy thick plate, comprising the following steps: residual heat online quenching → leveling rolling → plate shearing → stretching, and the specific steps include:

[0080] (1) Residual heat online quenching: The 6061 aluminum alloy plate with a thickness of 76.1 mm and a width of 2100 mm in the solid solution state after solution heating or hot rolling is transferred to the roller quenching zone of the hot rolling mill for cooling and quenching. The water pressure at the upper end of the quenching zone is 4.1 bar and the water pressure at the lower end is 3.9 bar to obtain the quenched aluminum alloy plate.

[0081] (2) Tempering: The quenched plate is tempered with a rolling force of 300 tons, a working roll bending roll of -120 tons, and a tempering speed of 40 m / min to obtain a tempered plate.

[0082] (3) Plate shearing: Shearing the flat rolled plate to obtain a sheared plate.

[0083] (4) Stretching: The sheared sheet was stretched using a sheet stretching machine, with a stretching elongation of 2.2%.

[0084] Compared with Example 3, the water pressure in the quenching zone is increased and the water pressure difference between the upper and lower ends is adjusted from 0.1 bar to 0.2 bar. After the above processing, the obtained plate has a transverse unevenness of 4.3 mm and a longitudinal unevenness of 3.2 mm.

[0085] Comparative Example 6

[0086] A method for controlling the flatness of a thick aluminum alloy plate subjected to online quenching by residual heat of hot rolling in this embodiment comprises the following steps: online quenching by residual heat → temper rolling → plate shearing → stretching, and the specific steps include:

[0087] (1) Residual heat online quenching: The 6061 aluminum alloy plate with a thickness of 76.1 mm and a width of 2100 mm in the solid solution state after solution heating or hot rolling is transferred to the roller quenching zone of the hot rolling mill for cooling and quenching. The water pressure at the upper end of the quenching zone is 3.0 bar and the water pressure at the lower end is 2.8 bar to obtain the quenched aluminum alloy plate.

[0088] (2) Tempering: The quenched plate is tempered with a rolling force of 300 tons, a working roll bending roll of -120 tons, and a tempering speed of 40 m / min to obtain a tempered plate.

[0089] (3) Plate shearing: Shearing the flat rolled plate to obtain a sheared plate.

[0090] (4) Stretching: The sheared sheet was stretched using a sheet stretching machine, with a stretching elongation of 2.2%.

[0091] Compared with Example 3, the water pressure in the quenching zone is reduced in this comparative example, and the water pressure difference between the upper and lower ends is adjusted from 0.1 bar to 0.2 bar. After the above processing, the obtained plate has a transverse unevenness of 4.1 mm and a longitudinal unevenness of 3.0 mm.

[0092] Comparative Example 7

[0093] The present comparative example provides a method for controlling the flatness of a hot-rolled residual heat online quenching aluminum alloy thick plate, comprising the following steps: residual heat online quenching → leveling rolling → plate shearing → stretching, and the specific steps include:

[0094] (1) Residual heat online quenching: The 6061 aluminum alloy plate with a thickness of 30.5 mm and a width of 1600 mm in the solid solution state after solution heating or hot rolling is transferred to the roller quenching zone of the hot rolling mill for cooling and quenching. The water pressure at the upper end of the quenching zone is 2.8 bar and the water pressure at the lower end is 2.6 bar to obtain the quenched aluminum alloy plate.

[0095] (2) Sheet shearing: Shear the quenched sheet to obtain a sheared sheet.

[0096] (3) Stretching: The sheared sheet was stretched using a sheet stretching machine, with a stretching elongation of 2.7%.

[0097] Compared with Example 1, this comparative example does not perform flattening rolling, but only performs stretching. After the above processing, the obtained plate has a transverse unevenness of 7.5 mm and a longitudinal unevenness of 3.0 mm.

[0098] Comparative Example 8

[0099] The present comparative example provides a method for controlling the flatness of a hot-rolled residual heat online quenching aluminum alloy thick plate, comprising the following steps: residual heat online quenching → leveling rolling → plate shearing → stretching, and the specific steps include:

[0100] (1) Residual heat online quenching: The 6061 aluminum alloy plate with a thickness of 30.5 mm and a width of 1600 mm in the solid solution state after solution heating or hot rolling is transferred to the roller quenching zone of the hot rolling mill for cooling and quenching. The water pressure at the upper end of the quenching zone is 2.8 bar and the water pressure at the lower end is 2.6 bar to obtain the quenched aluminum alloy plate.

[0101] (2) Sheet shearing: Shear the quenched sheet to obtain a sheared sheet.

[0102] (3) Stretching: The sheared sheet was stretched using a sheet stretching machine, with a stretching elongation of 3.0%.

[0103] Compared with Example 1, the tensile elongation of this comparative example is adjusted from 2.7% to 3.0%. After the above processing, the transverse unevenness of the obtained plate is 3.2 mm and the longitudinal unevenness is 2.5 mm.

[0104] In summary, in the present embodiment, a method for controlling the flatness of an aluminum alloy thick plate subjected to online quenching by residual heat from hot rolling is used. After online quenching water pressure control, leveling rolling and stretching after quenching, the transverse and longitudinal unevenness of the aluminum alloy plate are both ≤2.5mm. It can be seen from Examples 1-3 and Comparative Examples 1-6 that, compared with the embodiments of the present invention, the unevenness of the plate obtained by increasing or decreasing the upper and lower water pressures of online quenching and changing the water pressure difference increases; it can be seen from Examples 1-3 and Comparative Example 7 that the unevenness is reduced when leveling rolling is not performed and only stretching processing is performed; it can be seen from Examples 1-3 and Comparative Example 8 that an excessively high stretching rate will not reduce the unevenness in the present invention. In addition, compared with the conventional roller straightening process, the present invention utilizes the waste heat after hot rolling to directly flat-roll the long plates after hot rolling on the hot rolling mill at one time. The three processes of hot rolling, online quenching and flat-rolling are integrated in the hot rolling production line for continuous processing. First, the flat-rolling speed is faster than the plate straightening speed. Second, the stacking and transportation of plates are reduced. The overall speed can be increased by more than 3 times, and the production efficiency is higher.

[0105] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. The scope of the present invention is intended to be limited by the claims and their equivalents.

Claims

1. A method for controlling the flatness of aluminum alloy thick plates quenched online by hot rolling residual heat, characterized in that: include: Residual heat online quenching, temper rolling, plate shearing and stretching. The residual heat online quenching process parameters are: controlling the quenching water pressure according to the plate thickness, specifically: The quenching water pressure for plates with a thickness of 15 mm or less and ≤ 55 mm is 2.6 to 3.4 bar, and the water pressure at the upper end is 0.2 to 0.4 bar higher than the water pressure at the lower end; The quenching water pressure for plates with a thickness of 55mm and a thickness of ≤85mm is 3.2 to 3.8 bar and the difference between the upper and lower water pressures is -0.1 to 0.1 bar; The quenching water pressure for plates with a thickness of 85mm<≤150mm is 3.8~4.5bar and the difference between the upper and lower water pressures is -0.1~0.1bar.

2. The method for controlling the flatness of aluminum alloy thick plates subjected to online quenching by hot rolling residual heat according to claim 1, characterized in that: The residual heat online quenching process parameters are: The quenching water pressure for plates with a thickness of 15 mm or less and ≤ 55 mm is 2.8 to 3.2 bar, and the water pressure at the upper end is 0.2 to 0.3 bar higher than that at the lower end; The quenching water pressure for plates with a thickness of 55mm<≤85mm is 3.4~3.6bar and the difference between the upper and lower water pressures is -0.1~0.1bar; The quenching water pressure for plates with a thickness of 85mm<≤150mm is 3.9~4.3bar and the difference between the upper and lower water pressures is -0.1~0.1bar.

3. The method for controlling the flatness of aluminum alloy thick plates subjected to online quenching by hot rolling residual heat according to claim 1, characterized in that: In the temper rolling process, the rolling force is 200 to 400 tons.

4. The method for controlling the flatness of aluminum alloy thick plates subjected to online quenching by hot rolling residual heat according to claim 1, characterized in that: In the stretching process, a plate stretching machine is used to stretch the aluminum alloy thick plate, and the stretching elongation is 1.8-2.7%.

5. The method for controlling the flatness of aluminum alloy thick plates subjected to online quenching by hot rolling residual heat according to claim 1, characterized in that: In the temper rolling process, the working roll bending weight is -120 to 120 tons.

6. The method for controlling the flatness of aluminum alloy thick plates subjected to online quenching by hot rolling residual heat according to claim 1, characterized in that: In the temper rolling process, the temper rolling speed is 40 to 80 m / min.

7. The method for controlling the flatness of aluminum alloy thick plates subjected to online quenching by hot rolling residual heat according to claim 1, characterized in that: The thickness of the high-temperature aluminum alloy thick plate in a solid solution state after solid solution heating or hot rolling is 20 to 150 mm.

8. The method for controlling the flatness of aluminum alloy thick plates subjected to online quenching by hot rolling residual heat according to claim 1, characterized in that: The transverse and longitudinal unevenness of the aluminum alloy thick plate is ≤2.5mm.