Roller system structure and rolling method for rolling magnesium alloy thin strip

Abstract

The application discloses a rolling mill roller system structure and a rolling method for rolling magnesium alloy thin strips, which comprises upper supporting working rollers, lower supporting working rollers, upper working rollers, lower working rollers, front machine following steering rollers, rear machine following steering rollers, an uncoiler and a coiler, and magnesium alloy thin strips on the uncoiler pass through the upper supporting working rollers and the upper working rollers, the rear machine following steering rollers, the space between the upper working rollers and the lower working rollers, the front machine following steering rollers, the space between the lower supporting working rollers and the lower working rollers and are wound on the coiler in sequence in a rolling direction. The rolling mill roller system structure realizes one-time unwinding and winding of the magnesium alloy thin strips on a single-stand production line, three-pass rolling can be carried out in the unwinding and winding process, the number of heating and temperature compensation can be reduced, the four-drive asymmetric roller system body structure is adopted, the special requirements of the special lattice structure of the magnesium alloy thin strips on rolling deformation can be met, the anisotropy of the product can be reduced, and the product performance can be further improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal plate strip production technology and equipment technology in the metallurgical industry, in particular to a rolling mill roll system structure and rolling method for rolling magnesium alloy thin strips. BACKGROUND

[0002] Magnesium alloy plate has excellent characteristics such as light weight, high specific strength, good vibration damping performance, high shielding property, good heat dissipation performance, and affinity to the human body, and is widely used in the fields of national defense and military industry, aerospace, equipment manufacturing, and electronic product housings. At present, with the continuous change of market demand, magnesium alloy plate is developing in the direction of ultra-thin, wide, and high surface quality. However, the special lattice structure of magnesium alloy leads to a small number of slip systems at room temperature, easy cracking during cold rolling, low production efficiency, and low yield rate, and serious anisotropy. Generally, the magnesium alloy strip blank needs to be heated to 120-230℃ during cold rolling to complete the production with a small pass reduction rate (generally 5%-15%) and several passes.

[0003] Compared with the traditional block production method, the strip method has the advantages of strong continuous production, high consistency of product specifications and performance, high production efficiency and yield rate, and is suitable for large-scale batch production. Therefore, at present, magnesium alloy production enterprises begin to use the cold rolling mill and the strip method process previously mainly applied in the production of steel strips, copper strips, aluminum strips and other metal strips for the production of magnesium alloy thin strips.

[0004] Since magnesium alloy thin strips are difficult-to-deform metals with a special hexagonal close-packed lattice structure (other metals such as steel, copper, and aluminum are easy-to-deform metals with a body-centered cubic lattice structure), the rolling process requires characteristics such as short process, few passes, uniform temperature, and prevention of oxidation. During rolling, the contact between the hot magnesium alloy blank and the cold parts of the production equipment should be minimized to avoid temperature and deformation inhomogeneity, and the anisotropy caused by cumulative deformation during rolling should be reduced.

[0005] However, the roll system structure and rolling method of the conventional strip method cold rolling mill applied in the production of steel, copper, aluminum and other metal strips (see the attached drawings of the specification Figure 2 ) cannot meet the production requirements of magnesium alloy thin strips. The main reasons are as follows: 1. The single-stand cold rolling mill can only realize one pass during unwinding and winding, which requires multiple heating and temperature compensation during unwinding and winding; 2. The conventional roll system adopts a single support roll drive or a single working roll drive mode with completely symmetrical upper and lower structures, which makes the deformation of the magnesium alloy strip blank on the upper and lower sides completely symmetrical under the rolling pressure of the working roll, resulting in serious cumulative anisotropy and further reducing the performance of the product.

[0006] Therefore, the application provides a rolling mill roll train structure and rolling method for rolling magnesium alloy thin strips to solve the above problems. SUMMARY

[0007] The application aims to overcome the defects of the prior art and provide a rolling mill roll train structure and rolling method for rolling magnesium alloy thin strips, which has a compact structure and can realize one-time unwinding and coiling of magnesium alloy thin strips in a single stand production line, so that three passes of rolling can be performed, the number of heating and temperature compensation can be reduced, the eccentric configuration of the four-drive asymmetric roll train body structure can meet the special requirements of the special lattice structure of magnesium alloy thin strips on rolling deformation, can help reduce the anisotropy of the product, further improve the performance of the product, and effectively solve the problems in the background art.

[0008] To achieve the above object, the application provides the following technical scheme: a rolling mill roll train structure for rolling magnesium alloy thin strips, comprising upper support work rolls, lower support work rolls, upper work rolls, lower work rolls, front machine follow-up deflection rolls, rear machine follow-up deflection rolls, an unwinder and a coiler, and the magnesium alloy thin strips on the unwinder pass through the upper support work rolls and the upper work rolls, the rear machine follow-up deflection rolls, the space between the upper work rolls and the lower work rolls, the front machine follow-up deflection rolls, the space between the lower support work rolls and the lower work rolls in sequence along the rolling direction, and are coiled on the coiler.

[0009] As a preferred technical scheme of the application, the upper support work rolls, the lower support work rolls, the upper work rolls and the lower work rolls are all motor-driven driving rolls.

[0010] As a preferred technical scheme of the application, the upper support work rolls and the lower support work rolls are eccentric to the front side of the unwinder and the rear side of the coiler along the vertical center lines of the upper work rolls and the lower work rolls by a distance of 10-50 mm, forming a four-drive asymmetric roll train body structure.

[0011] As a preferred technical scheme of the application, the relationship between the radius R of the upper support work rolls and the lower support work rolls and the radius r of the upper work rolls and the lower work rolls is R=1.8-2.2r.

[0012] As a preferred technical scheme of the application, the front machine follow-up deflection rolls and the rear machine follow-up deflection rolls are both electromagnetic induction heating rolls, the center elevations and the roll radii of the front machine follow-up deflection rolls and the rear machine follow-up deflection rolls are the same as the center elevations and the work roll radii r of the lower work rolls and the upper work rolls, which are used to heat the magnesium alloy thin strips to 90-300 DEG C, change the wrapping angle of the magnesium alloy thin strips to 180 DEG and deflect the running direction of the magnesium alloy thin strips by 180 DEG, and heat the magnesium alloy thin strips to the process rolling temperature while the magnesium alloy thin strips are deflected by the front machine follow-up deflection rolls and the rear machine follow-up deflection rolls.

[0013] As a preferred technical scheme of the present application, the upper support work roll and the upper work roll form an upper roll gap, the lower support work roll and the lower work roll form a lower roll gap, and the upper work roll and the lower work roll form a center roll gap.

[0014] As a preferred technical scheme of the present application, the uncoiler and the front follow-up deflector roll and the coiler and the rear follow-up deflector roll are respectively provided with a front deflector roll and a rear deflector roll, the front deflector roll is used for deflecting the magnesium alloy thin strip in the angle and direction between the uncoiler and the upper roll gap, and the rear deflector roll is used for deflecting the magnesium alloy thin strip in the angle and direction between the lower roll gap and the coiler, and the center elevations of the front deflector roll and the rear deflector roll are the same as the rolling line elevation of the center roll gap.

[0015] A rolling method of a rolling mill roll train structure for rolling magnesium alloy thin strips, the rolling method comprising: during rolling of the magnesium alloy thin strips, one uncoiling and coiling in one single rolling pass realizes continuous three-pass deformation, i.e., three passes, the first pass is deformed between the upper support work roll and the upper work roll, the second pass is deformed between the upper work roll and the lower work roll, and the third pass is deformed between the lower support work roll and the lower work roll.

[0016] As a preferred technical scheme of the present application, the first pass of the single-pass continuous three-pass rolling is that the upper support work roll rotates counterclockwise and the upper work roll rotates clockwise, the second pass is that the upper work roll rotates clockwise and the lower work roll rotates counterclockwise, and the third pass is that the lower work roll rotates counterclockwise and the lower support work roll rotates clockwise.

[0017] Compared with the prior art, the present application has the following beneficial effects:

[0018] 1. The rolling mill roll train structure and the rolling method for rolling magnesium alloy thin strips realize one uncoiling and coiling process in one single stand production line, and three-pass rolling can be realized, so that the production efficiency is improved, and the uniformity of the temperature and deformation in the magnesium alloy thin strip production process is ensured.

[0019] 2. The rolling mill roll train structure and the rolling method for rolling magnesium alloy thin strips increase the one-pass deformation from one-pass deformation force to three-pass deformation, greatly reduce the power consumption and other energy consumption, and reduce the production cost.

[0020] 3. The rolling mill roll train structure and the rolling method for rolling magnesium alloy thin strips, the entire roll train includes the upper support work roll, the lower support work roll, the upper work roll, and the lower work roll, which are all driving rolls, and the upper support work roll and the lower support work roll are respectively eccentric to the front and rear of the machine by a certain distance, so that the special requirements of the special lattice structure of the magnesium alloy thin strip on the rolling deformation are met, and the anisotropy of the product is reduced.

[0021] 4. The rolling mill roll train structure and rolling method of the example of the application, the production line is compactly arranged, compared with the traditional 3-stand continuous rolling production line capable of realizing single-rolling-process 3-passes, the equipment investment and workshop floor area are reduced.

[0022] 5. The rolling mill roll train structure and rolling method of the example of the application, the structure is compact, the single-stand production line realizes the once-unwinding and coiling process of the magnesium alloy thin strip, that is, the rolling can be performed in 3 passes, the heating and temperature compensation times are reduced, meanwhile, the four-drive asymmetric roll train body structure is adopted, after the roll train is eccentrically arranged, the special requirements of the special lattice structure of the magnesium alloy thin strip on the rolling deformation can be met, the anisotropy of the product is reduced, and the product performance is further improved. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of the application;

[0024] Figure 2 It is a schematic diagram of the roll train structure of a traditional cold rolling mill.

[0025] In the figure, 1 is an upper supporting work roll, 2 is a lower supporting work roll, 3 is an upper work roll, 4 is a lower work roll, 5 is a front follow-up deflector roll, 6 is a rear follow-up deflector roll, 7 is a front deflector roll, 8 is a rear deflector roll, 9 is an unwinder, and 10 is a coiler. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0027] Please refer to Figures 1-2 The application provides a technical solution: a rolling mill roll train structure for rolling a magnesium alloy thin strip, which comprises an upper supporting work roll 1, a lower supporting work roll 2, an upper work roll 3, a lower work roll 4, a front follow-up deflector roll 5, a rear follow-up deflector roll 6, an unwinder 9 and a coiler 10, as shown in Figure 1 The magnesium alloy thin strip on the unwinder 9 passes through the upper supporting work roll 1 and the upper work roll 3, the rear follow-up deflector roll 6, the space between the upper work roll 3 and the lower work roll 4, the front follow-up deflector roll 5, the space between the lower supporting work roll 2 and the lower work roll 4 in sequence along the rolling direction, and is coiled on the coiler 10, so that the single-stand production line realizes the once-unwinding and coiling process of the magnesium alloy thin strip, that is, the rolling can be performed in 3 passes, the production efficiency is improved, and the uniformity of the temperature and deformation in the production process of the magnesium alloy thin strip is ensured.

[0028] The conventional one-time press-down deformation force is increased from one time to three times, the energy consumption such as power consumption is greatly reduced, and the production cost is reduced; the production line is compactly arranged, compared with the traditional three-stand continuous rolling production line capable of realizing single rolling process three passes, the equipment investment and workshop floor area are reduced.

[0029] Further, for the mode of driving only one pair of work rolls in the traditional rolling roller system and the back-up roll is a back-up dynamic roll or the mode of driving only one pair of back-up rolls and the work roll is a dynamic roll, only the linear speed of the upper and lower deformation layers of the magnesium alloy strip can be completely consistent, which is not suitable for the process requirements of magnesium alloy thin strip production, in the invention, the upper back-up work roll 1, the lower back-up work roll 2, the upper work roll 3 and the lower work roll 4 are all motor-driven driving rolls, and the speed of each driving motor can be adjusted according to the speed difference of the upper and lower deformation layers of the magnesium alloy thin strip.

[0030] Further, the upper back-up work roll 1 and the lower back-up work roll 2 are eccentric to the vertical center lines of the upper work roll 3 and the lower work roll 4 by a distance of 10-50mm to the front side of the decoiler 9 and the rear side of the coiler 10 respectively, forming a four-drive asymmetric roller system body structure, after the eccentric configuration of the roller system, the running direction of the magnesium alloy thin strip can be process deflected by a certain angle, and the deformation layer can be formed into an asymmetric structure.

[0031] The rollers of the whole roller system include the upper back-up work roll 1, the lower back-up work roll 2, the upper work roll 3 and the lower work roll 4, which are all driving rollers, and the upper back-up work roll 1 and the lower back-up work roll 2 are eccentric to the front and rear of the machine by a certain distance, which meets the special requirements of the special lattice structure of the magnesium alloy thin strip on rolling deformation, and is beneficial to reduce the anisotropy of the product.

[0032] Further, the relationship between the radius R of the upper back-up work roll 1 and the lower back-up work roll 2 and the radius r of the upper work roll 3 and the lower work roll 4 is R=1.8-2.2r.

[0033] Further, the front dynamic deflection roller 5 and the rear dynamic deflection roller 6 are both electromagnetic induction heating rollers, the center elevation and roller radius of the front dynamic deflection roller 5 and the rear dynamic deflection roller 6 are the same as those of the lower work roll 4 and the upper work roll 3, which are used for heating the magnesium alloy thin strip to 90-300℃ and 180° wrapping angle, and changing the running direction of the strip by 180°, the magnesium alloy thin strip is heated to the process rolling temperature while being deflected by 180° by the front dynamic deflection roller 5 and the rear dynamic deflection roller 6, and the front dynamic deflection roller 5 and the rear dynamic deflection roller 6 with electromagnetic heating function only heat the magnesium alloy thin strip, adjust the temperature and wrapping angle, and change the running direction by 180°.

[0034] Further, the upper support work roll 1 and the upper work roll 3 form an upper roll gap, the lower support work roll 2 and the lower work roll 4 form a lower roll gap, and the upper work roll 3 and the lower work roll 4 form a center roll gap.

[0035] Further, a front deflector roll 7 and a rear deflector roll 8 are arranged between the uncoiler 9 and the front follow-up turn roll 5 and between the coiler 10 and the rear follow-up turn roll 6, respectively. The front deflector roll 7 is used to deflect the magnesium alloy thin strip by an angle and a direction between the uncoiler 9 and the upper roll gap, and the rear deflector roll 8 is used to deflect the magnesium alloy thin strip by an angle and a direction between the lower roll gap and the coiler 10. The center elevation of the front deflector roll 7 and the rear deflector roll 8 is the same as the rolling line elevation of the center roll gap.

[0036] A rolling method of a rolling roll system structure for rolling a magnesium alloy thin strip, which comprises: during rolling of the magnesium alloy thin strip, one uncoiling and coiling per single rolling pass realizes continuous three-pass deformation, i.e., three passes of rolling. The first pass is deformed between the upper support work roll 1 and the upper work roll 3, the second pass is deformed between the upper work roll 3 and the lower work roll 4, and the third pass is deformed between the lower support work roll 2 and the lower work roll 4.

[0037] Further, the first pass of the single rolling pass continuous three-pass rolling is that the upper support work roll 1 rotates counterclockwise and the upper work roll 3 rotates clockwise; the second pass is that the upper work roll 3 rotates clockwise and the lower work roll 4 rotates counterclockwise; and the third pass is that the lower work roll 4 rotates counterclockwise and the lower support work roll 2 rotates clockwise.

[0038] During the above single rolling pass three-pass rolling of the magnesium alloy thin strip, in addition to the upper work roll 3 and the lower work roll 4 directly participating in contact with the strip for rolling, compared with the conventional method, the upper support work roll 1 and the lower support work roll 2 only support the work roll. In the present application, the upper support work roll 1 and the lower support work roll 2 also contact the strip and participate in rolling.

[0039] As Figure 1 , the process of the single rolling pass three-pass rolling of the magnesium alloy thin strip is as follows:

[0040] The magnesium alloy thin strip is guided to the upper support work roll 1 and the upper work roll 3 under the action of the front deflector roll 7 of the uncoiler 9 to complete the first-pass rolling;

[0041] Then, the magnesium alloy thin strip is guided to the upper work roll 3 and the lower work roll 4 under the angle and 180° turning action of the rear follow-up turn roll 6 to complete the second-pass rolling;

[0042] Then, the magnesium alloy thin strip is guided to the lower work roll 4 and the lower support work roll 2 under the angle and 180° turning action of the front follow-up turn roll 5 to complete the third-pass rolling;

[0043] Finally, the magnesium alloy thin strip is guided to the coiler 10 under the action of the deflector roller 8 after the machine, and the single rolling process 3-pass production is completed.

[0044] The application has compact structure, and realizes the once-unwinding and coiling process of the magnesium alloy thin strip by the single stand production line, so that the 3-pass rolling can be performed, the heating and temperature compensation times can be reduced, the four-drive asymmetric roller system body structure is adopted, the roller system is eccentrically arranged, the special requirements of the special lattice structure of the magnesium alloy thin strip on the rolling deformation can be met, the anisotropy of the product can be reduced, and the product performance is further improved.

[0045] The non-disclosed parts in the application are all prior art, and the specific structure, material and working principle are not described in detail. Although the embodiments of the application have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirits of the application, and the scope of the application is defined by the appended claims and their equivalents.

Claims

1. A roll system structure for rolling magnesium alloy thin strips, characterized in that, The machine includes an upper support work roll (1), a lower support work roll (2), an upper work roll (3), a lower work roll (4), a front follow-up steering roll (5), a rear follow-up steering roll (6), an uncoiler (9), and a coiler (10). The magnesium alloy strip on the uncoiler (9) passes sequentially along the rolling direction between the upper support work roll (1) and the upper work roll (3), the rear follow-up steering roll (6), the upper work roll (3) and the lower work roll (4), the front follow-up steering roll (5), and the lower support work roll (2) and the lower work roll (4). And it is wound onto the winding machine (10). The upper support working roller (1) and the lower support working roller (2) are eccentrically positioned 10-50mm from the vertical center line of the upper working roller (3) and the lower working roller (4) to the front side of the machine where the uncoiler (9) is located and the rear side of the machine where the winding machine (10) is located, respectively, forming a four-drive asymmetric roller system body structure. The relationship between the radius R of the upper support working roller (1) and the lower support working roller (2) and the radius r of the upper working roller (3) and the lower working roller (4) is: R=1.8-2.2r.

2. The roll system structure for rolling magnesium alloy thin strip according to claim 1, characterized in that: The upper support working roller (1), lower support working roller (2), upper working roller (3) and lower working roller (4) are all motor-driven active rollers.

3. The roll system structure for rolling magnesium alloy thin strip according to claim 1, characterized in that: The front follow-up turning roller (5) and the rear follow-up turning roller (6) are both electromagnetic induction heating rollers. The center elevation and roller radius of the front follow-up turning roller (5) and the rear follow-up turning roller (6) are the same as the center elevation and working roller radius r of the lower working roller (4) and the upper working roller (3), respectively. They are used to heat the magnesium alloy strip to 90℃-300℃ and make a 180° wrap angle, and change the running direction of the strip in one pass to a 180° deflection. The magnesium alloy strip is heated to the process rolling temperature while the wrap angle of the front follow-up turning roller (5) and the rear follow-up turning roller (6) is turned.

4. The roll system structure for rolling magnesium alloy thin strip according to claim 1, characterized in that: An upper roller gap is formed between the upper support working roller (1) and the upper working roller (3), a lower roller gap is formed between the lower support working roller (2) and the lower working roller (4), and a central roller gap is formed between the upper working roller (3) and the lower working roller (4).

5. The roll system structure for rolling magnesium alloy thin strip according to claim 4, characterized in that: Between the uncoiler (9) and the front follower roller (5), and between the coiler (10) and the rear follower roller (6), a front deflector roller (7) and a rear deflector roller (8) are respectively provided. The front deflector roller (7) is used to deflect the magnesium alloy strip between the uncoiler (9) and the upper roll gap. The rear deflector roller (8) is used to deflect the magnesium alloy strip between the lower roll gap and the coiler (10). The center elevation of the front deflector roller (7) and the rear deflector roller (8) is the same as the rolling line elevation of the center roll gap.

6. A rolling method based on the roll system structure for rolling magnesium alloy thin strip according to any one of claims 1-5, characterized in that: The rolling method includes: when rolling magnesium alloy strip, each single rolling stroke involves one uncoiling and one winding to achieve three consecutive pressing deformations, i.e., three passes of rolling. The first pass is the deformation between the upper support work roll (1) and the upper work roll (3), the second pass is the deformation between the upper work roll (3) and the lower work roll (4), and the third pass is the deformation between the lower support work roll (2) and the lower work roll (4).

7. The rolling method for the roll system structure for rolling magnesium alloy thin strip according to claim 6, characterized in that: In a single rolling process with three consecutive passes, the first pass involves the upper support work roll (1) rotating counterclockwise and the upper work roll (3) rotating clockwise; the second pass involves the upper work roll (3) rotating clockwise and the lower work roll (4) rotating counterclockwise; and the third pass involves the lower work roll (4) rotating counterclockwise and the lower support work roll (2) rotating clockwise.

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