WO2022217717A1

WO2022217717A1 - Rolling method for wide metal strip foil

Info

Publication number: WO2022217717A1
Application number: PCT/CN2021/097720
Authority: WO
Inventors: 刘洪勤; 马力; 徐继玲; 李毅
Original assignee: 上海五星铜业股份有限公司
Priority date: 2021-04-16
Filing date: 2021-06-01
Publication date: 2022-10-20
Also published as: CN113290052A; CN113290052B

Abstract

A rolling method for wide metal strip foil. A rolling mill provided with working rollers of unequal diameters is used, and the roller diameter of one working roller of the rolling mill is greater than the roller diameter of the other working roller; during rolling, the linear speeds of roller faces of the two working rollers (1,2) are the same, metal strip foil (5) is wrapped on the roller face of one working roller to form a wrapping arc at an inlet side or an outlet side of a roller gap formed by the two working rollers, and the tension is uniformly distributed on the cross section of the wrapping arc by means of the back support of the working roller on the metal strip foil. By means of the method, the rolling mill provided with the working rollers of unequal diameters is used, which is beneficial for thinning strip foil and obtaining a better plate shape. In addition, by means of the method, the strip foil forms a wrapping arc on the working roller, and by means of the back support of the working roller on the strip foil, the front tension is uniformly distributed on the cross section of the wrapping arc at the inlet side, thereby achieving uniform-tension rolling of the strip foil, and breaking through the bottleneck of the development of a strip foil into a wider, thinner and more ideal plate shape being restricted, thereby solving the technical problem in the industry.

Description

A rolling method of wide metal strip foil

technical field

The invention relates to the technical field of rolling, in particular to a rolling method for high-precision wide-width metal strips and foils, which is used to obtain a good plate shape.

Background technique

With the advancement of science and technology industry, the market demand for high-precision wide-width thin strips and foils (hereinafter referred to as strips and foils) is more and more urgent. Under the current technical background, the rolling technology for wide and thick strips is basically mature, but the rolling technology of high-precision wide and thinner strips and foils has shown technical bottlenecks, which are in urgent need of breakthroughs. For thicker strips, even if there are plate shape defects after rolling, the plate shape can still be corrected by tension leveling or other flattening means, while for thinner strip foils, especially very thin foils, due to the lack of follow-up The original rolling shape is the final shape of the product. Especially for the strip foil with high deformation resistance such as copper, copper alloy, stainless steel, etc., it is difficult to achieve stable high-quality production due to the restriction of the shape control ability of the existing rolling technology. According to known information, the thinnest rolling thickness that can be achieved by mass production of pure copper foil is 0.006mm and the maximum width is 650mm. The minimum rolling thickness that can be achieved by mass production of stainless steel foil is 0.02mm and the maximum width is 600mm. And the rolled shape is not very good, if the width continues to increase, the shape will become worse.

The three basic conditions for stable rolling of a rolling mill are roll accuracy, lubrication conditions and tension accuracy. For the rolling of ultra-thin strip foil, the reduction effect of the reduction amount is weakened, and the thickness reduction of the strip foil is basically achieved by the flattening rebound amount of the work roll, the rolling speed, and the larger unit tension. The tension selected for thicker strip rolling usually does not exceed 16% of the yield strength of the strip, so the effect of tension on strip thinning is not obvious, and its main role is to establish a stable rolling operation. The very thin thickness of the strip foil rolling is quite different. In order to make full use of the thinning effect of the tension on the strip foil, the unit tension used even reaches 60% of the yield strength of the material. Since the large tension has a great effect on the thinning of the strip foil, and naturally also has a large influence on the rolled sheet shape, the influence of the tension on the sheet shape is mainly manifested in the uniformity of the distribution of the tension on the cross section of the strip foil.

As shown in Figure 1, in an ideal situation, on the cross section (including the edge) of the foil, the tension per unit width is uniform and the size is the same, but this is not the case in actual production. The actual tension distribution is shown in Figure 2. In Figure 2, the distribution of tension on the cross section of the foil is not uniform. The tension value of the two edges of the foil is the largest, while the tension value in the middle part is small. ΔT in the figure is the tension The difference between the maximum value and the minimum value distributed in the direction of the width B of the tape foil can be referred to as the ratio ΔT/B as the unevenness of the tension. There are many factors that cause the non-uniform tension of the strip foil on the cross section. One type of factors comes from the non-uniformity of material composition, structure and annealing, and these factors are random; the other type of factors comes from rolling conditions, such factors There are rules to be found, such as the sudden reduction of the edge thickness of the strip foil in the process of multiple thinning and rolling, this phenomenon is recorded in the paper "Three-dimensional Analysis of Cold Rolled Strip Deformation", the paper The variation of the edge drop and lateral flow with the edge distance of the plate after rolling was simulated and calculated by the finite element method. According to the roll pressure formula:

It can be seen that the fluctuation of the thickness of the region is accompanied by the lateral flow of the metal material (macroscopically manifested as abnormal plate shape), and the lateral flow of the metal material causes the fluctuation of the rolling force P1 in the region, and the fluctuation of the rolling force P1 causes the The tension S1 fluctuates. Then, in turn, the fluctuation of the tension S1 in the area will lead to the fluctuation of the rolling force P1, and the fluctuation of the rolling force P1 will affect the lateral flow of the metal material, which are cause and effect. This shows that during the rolling process, the tension applied to the cross-section of the strip foil is not uniform, and the non-uniformity of this tension is ubiquitous.

In the rolling process, the pre-tension and post-tension have a great influence on the shape of the strip, which is recorded in the paper "The Influence of Tension on the Deformation of Cold-Rolled Strip", which is discussed in detail through a three-dimensional simulation system. Increasing the front and rear tension limits the lateral flow of the metal, which can increase the thickness deformation of the strip and make the thickness of the section more uniform. For the tape foil, increasing the front tension and back tension has a greater effect on the shape of the tape foil. The tension of the strip foil is uneven per unit width, and the deformation resistance, roll gap, and material thickness of the local rolling will be uneven, which will eventually lead to defects (including potential defects) in the rolled sheet shape, such as often in the rolling process. Waves, wrinkles appear. What's more serious is that the drastic change in the tension of the two sides will cause the foil to have cracks on both sides. Once a crack occurs, it will rapidly extend laterally, thus causing the foil to break. The wider the foil, the greater the unevenness of tension, and the more difficult to control the shape of the strip. This is the technical bottleneck that restricts the development of the foil to a wider, thinner and more ideal shape. It is also difficult for the industry for a long time. The key to solving the problem is how to make the tension evenly distributed on the cross section of the foil.

As shown in Fig. 3, this is the typical layout of the current strip foil rolling. Regardless of domestic or foreign countries, the strip foil 5 enters horizontally along the rolling center line 6 after passing through the lifting roller 4 and the flattening roller 3. in the roll gap. It can be seen from Figure 3 that before the belt foil 5 enters the roll gap, the section of the belt foil between the lower work roll 2 and the flattening roll 3 is always in a suspended state, which solves the problem of the tension on the cross section of the belt foil. Uneven distribution is crucial and directly affects the success or failure of high-precision wide strip foil rolling. According to the national standard, the high level error of the rolling center line 6 is required to be within 0.05mm/m. The reason for such a high requirement is to ensure the stability of the neutral plane of the strip to achieve uniform mechanical properties of the strip. However, this is difficult to achieve in actual production. Factors such as the jitter of the lifting roll under the action of the oil cylinder, the roll diameter error of the flattening roll and the work roll, and the overhang of the strip will cause the neutral surface of the strip to deviate to a certain direction. On the other hand, this deviation phenomenon is particularly serious for thin strip foils, and there is no better solution at present.

In addition, as shown in Figure 4, the upper work roll 1 and the lower work roll 2 of the rolling mill are designed with equal diameters, both domestic and foreign, ranging from two-high rolling mills to twenty-high rolling mills. Such a design is conducive to the maintenance and exchange of work rolls, and for the rolling mill, its transmission structure is thus simplified. The size of the work roll diameter has an influence on the rolling of the strip. It is well known that the smaller the diameter of the work rolls, the more beneficial the thinning of the strip foil 5, but it also brings problems: in Fig. Large, the lateral component of the rolling force is large, and therefore, its lateral bending tendency is large. In addition, the length of the bite arc of the left work roll to the belt foil 5 is short, which is not conducive to evenly bringing the lubricating medium into the roll gap, resulting in uneven thickness of the oil film in the rolling arc area. These factors lead to the large fluctuation of the arc length of the rolled arc surface along the width direction of the strip foil, which eventually leads to defects in the rolled sheet shape. Under the same conditions, the diameter of the right work roll is large, the rigidity is large, the bite angle to the strip foil 5 is small, and the lateral component of the rolling force is small, so the lateral bending tendency is small. In addition, the bite arc length of the right work roll to the belt foil 5 is longer, which is conducive to bringing the lubricating medium into the roll gap uniformly, so that the thickness of the oil film in the rolling arc area is more uniform. These factors are all beneficial to reduce the arc length fluctuation of the rolled arc surface along the width direction of the strip foil, so as to obtain a better rolled sheet shape.

To sum up, work rolls with small diameters are beneficial for thinning, but are limited by the difficulty in controlling the rolling shape, so the rolling width should not be too large; while large-diameter work rolls are conducive to the control of rolling shape and are suitable for rolling. Wide, but not suitable for thinning. For wide strip foil with a thickness of less than 0.3mm, the diameter of the work roll must be small enough (usually 25-50mm in diameter) to obtain a large reduction in rolling, and the plate shape at this time will be very difficult to control , which is also the current bottleneck restricting the rolling of high-precision and wide-width strip foils.

SUMMARY OF THE INVENTION

In order to overcome the deficiencies in the background technology, the present invention discloses a rolling method of a wide metal strip foil, the purpose of which is:

1. The tension is evenly distributed on the cross section of the strip foil, and the metal strip foil is evenly rolled;

2. Overcome the technical difficulties in the background technology, break the technical bottleneck, and enable the strip foil to be rolled with wide width and high precision.

For realizing the above-mentioned purpose of the invention, the present invention adopts following technical scheme:

A rolling method of wide metal strip foil, using a rolling mill with unequal diameter work rolls, the roll diameter of one work roll of the rolling mill is larger than the roll diameter of another work roll; The linear velocity of the roll surface of the rolls is the same, and at the entrance or exit side of the roll gap formed by the two work rolls, the metal strip foil is wrapped on the roll surface of a certain work roll to form a wrapping arc, which passes through the pair of work rolls. The backing of the metal strip foil, so that the tension is evenly distributed over the cross section of the cladding arc.

In a further improvement of the technical scheme, the metal strip foil is wrapped on the roll surface of the work roll with a larger roll diameter to form a wrapping arc.

To further improve the technical solution, the cladding arc is obtained by changing the angle of the metal strip foil entering or exiting the roll gap.

To further improve the technical solution, the cladding angle of the cladding arc is α, 0°<α≤90°.

The technical solution is further improved. On the inlet side and the outlet side of the roll gap, the metal strip foil is wrapped on the roll surface of the same or different work rolls to form an inlet side cladding arc and an outlet side cladding arc.

In a further improvement of the technical solution, the metal strip foil is wrapped on the roll surface of the work roll with a larger roll diameter.

To further improve the technical solution, the cladding arc on the inlet side is obtained by changing the angle at which the metal strip foil enters the roll gap, and the cladding arc on the outlet side is obtained by changing the angle at which the metal strip foil flows out of the roll gap.

Further improving the technical solution, the roll diameter of the work roll with a larger roll diameter is 1.5-5 times that of the work roll with a small roll diameter.

To further improve the technical scheme, before the next pass of rolling, the metal strip foil is turned over, and then enters the rolling mill for rolling.

To further improve the technical solution, the total number of rolling passes of the metal strip and foil is an even number.

Due to adopting the above-mentioned technical scheme, compared with the background technology, the present invention has the following beneficial effects:

It can be seen from Example 1 that the present invention uses a rolling mill with unequal diameter work rolls to roll the strip foil, which is not only conducive to the thinning of the strip foil, but also conducive to obtaining a better plate shape, breaking through the expectations of those skilled in the art. Awareness of mill work rolls. In addition, in the present invention, on the inlet side of the unequal diameter work roll gap, the belt foil forms a covering arc on the work roll, and the back support of the belt foil by the work roll makes the front tension cover the cross section of the arc at the inlet side. It is evenly distributed on the top of the strip, which realizes the uniform rolling of the strip foil, breaks through the bottleneck restricting the development of the strip foil to a wider, thinner and more ideal shape, and solves the technical problems that have been difficult to solve in the industry for a long time. Therefore, It has great application value and economic value. In addition, the fact that the strip foils are not placed horizontally along the rolling centerline breaks the perception within the industry, which is inherently inventive.

It can be seen from Example 2 that the present invention makes the belt foil form a covering arc on the roll surface of the work roll at the exit side of the roll gap of the unequal diameter work roll, and realizes the uniform distribution of the back tension on the covering arc on the exit side. The generation of defects such as waves and wrinkles is eliminated at the critical early stage of foil rolling, and then the backing of the foil by the work rolls stabilizes the shape of the foil in the later stage of rolling, thereby obtaining Preferred shape.

It can be seen from Examples 3 and 4 that the present invention combines the equalizing effect of the cladding arc on the inlet side and the cladding arc on the outlet side, and on the basis of the beneficial effects of Examples 1 and 2, it overcomes the unequal diameter work. The disadvantage brought about by roll rolling not only solves the problem of curling and deformation of the foil, but also unexpectedly solves the problem of different brightness of the upper and lower surfaces of the foil.

It is particularly important that the slip thinning of the present invention not only has the effect of extrusion thinning, but also has the effect of rolling thinning, and the neutral plane is stabilized at the middle layer of the foil, thereby ensuring the mechanical properties of the foil. uniformity. The invention breaks through the strict requirements on the rolling center line in the national standard, realizes the stability of the neutral plane in a real engineering manner, and solves the technical problems that cannot be solved by the prior art, so it is creative.

For the rolling of ultra-thin strip foil, it is basically zero roll gap or negative roll gap rolling, and it is very difficult to reduce its thickness while ensuring the stability of its plate shape, and this is also the problem to be solved in the present invention. core issue. The present invention adopts the rolling scheme of unequal diameter work rolls, which has more advantages than disadvantages, is generally beneficial to the thinning of the strip foil, and is also beneficial to obtain a better plate shape, which cannot be achieved by the existing equal diameter work rolls technical effect. The present invention is undoubtedly a technical breakthrough for the rolling of high-precision and wide-width strip foils that have been trapped in technical bottlenecks for a long time.

It is known that the thinner the strip foil, the more difficult it is to control the rolled shape. At present, the industry is doing everything possible to break through the limit, but no effective solution has been found. The significance of using unequal diameter work rolls in the present invention is that although a part of the thinning of the strip foil is sacrificed and the rolling passes (the number of reciprocating rolling) are slightly increased, the important thing is to keep the shape of the strip stable, The occurrence of rolling defects caused by the increase of the width is avoided or reduced, which is of great significance for the high-precision rolling of wide-width strip foils.

In addition, the present invention uses unequal diameter work rolls to roll the strip foil, which breaks through the knowledge and prejudice of those skilled in the art on the rolling mill work rolls, and provides a new idea for the design of the rolling mill and the improvement of the rolling process. The rolling method of the present invention also overcomes the shortcomings brought about by the rolling of unequal diameter work rolls, and provides a new technical solution for the rolling of wide-width high-precision strip foils.

The invention breaks through the technical bottleneck and provides a new technical solution for the rolling of wide-width high-precision strip foils.

Description of drawings

Figure 1 is a schematic diagram of the tension distribution applied to the cross section of the tape foil under ideal conditions.

Figure 2 is a schematic diagram of the tension distribution actually applied to the cross section of the tape foil.

Figure 3 shows a typical arrangement for current strip foil rolling.

FIG. 4 is a schematic structural diagram of a work roll of a conventional rolling mill.

FIG. 5 is a schematic structural diagram of the present invention in Embodiment 1. FIG.

Figure 6 is a schematic diagram of a belt drive.

Figure 7 is the force analysis diagram of a volume element on the cladding arc.

Figure 8 is a force analysis diagram of a volume unit when the foil is in the state of no backing.

Figure 9 is a force analysis diagram of a volume unit when the foil is in a back-supported state.

Fig. 10 is a diagram showing the distribution of tension in the thickness direction of a certain volume unit on the cladding arc on the entrance side of the roll gap in Example 1.

Figure 11 is a flow velocity distribution diagram of the upper and lower layers of the belt foil in the calendering zone.

FIG. 12 is a schematic structural diagram of the present invention in Embodiment 2. FIG.

Fig. 13 is a diagram showing the distribution of tension in the thickness direction of a certain volume unit on the cladding arc on the exit side of the roll gap in Example 2.

FIG. 14 is a schematic structural diagram of the present invention in Embodiment 3. FIG.

FIG. 15 is a diagram showing the distribution of tension in the thickness direction of a certain volume unit on the cladding arc on the exit side of the roll gap in Example 3. FIG.

FIG. 16 is a schematic diagram of the principle of slip thinning.

FIG. 17 is a schematic structural diagram of the present invention in Embodiment 4. FIG.

FIG. 18 is a partial enlarged schematic view of the structure of FIG. 17 .

In the figure: 1. Upper working roll; 2. Lower working roll; 3. Flattening roll; 4. Lifting roll; 5. Belt foil; 6. Rolling center line; 7. Driving pulley; 8. Belt; 9. volume unit.

Detailed ways

Preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principle of the present invention, and are not intended to limit the protection scope of the present invention. It should be noted that, in the description of the present invention, the terms "front", "rear", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", The terms indicating the direction or positional relationship such as "outside" are based on the direction or positional relationship shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, a specific The orientation configuration and operation are therefore not to be construed as limitations of the present invention.

Example 1:

The invention discloses a rolling method of wide metal strip and foil, which is used for rolling copper alloy strip and foil. The final rolling thickness of copper alloy strip and foil is 0.01mm and the width is 800mm. The thickness of the boundary between the strip and the foil is 0.15mm, and the thickness of the copper alloy strip foil (hereinafter referred to as the strip foil) already belongs to the foil. Due to the large deformation resistance of copper alloys, it is difficult to ensure the flatness of the plate shape.

As shown in Fig. 5, a flattening roller 3 is arranged on the entrance side of the roll gap. The roll surface of the flattening roller 3 is lower than the rolling center line 6. In the roll gap formed by a pair of work rolls, the roll diameter of the upper work roll 1 is 30 mm, the roll diameter of the lower work roll 2 is 60 mm, and the roll diameter of the lower work roll 2 is twice the roll diameter of the upper work roll 1. In order to prevent the upper and lower sheet surfaces of the strip foil 5 from curling due to the difference in the linear velocity of rolling, the linear velocity of the roll surfaces of the upper work roll 1 and the lower work roll 2 is the same during rolling. Since the strip foil 5 forms a certain angle with the rolling centerline 6 before entering the roll gap, the strip foil 5 forms an entry-side cladding arc on the roll surface of the lower work roll 2, and the entry-side cladding arc is covered The angle is α, and α is 30°. Due to the existence of the cladding arc on the inlet side, the lower work roll 2 backs up the belt foil 5, and the tension is evenly distributed on the cross section of the cladding arc on the inlet side. The principle is as follows:

As shown in FIG. 6 , in the transmission of the belt 8, the driving pulley 7 drives the belt 8 to rotate clockwise. Point A is the entry point of the belt 8 into the driving pulley 7, and point B is the cutout of the belt 8 from the driving pulley 7. point. In the cladding arc on the entrance side from point A to point B, the frictional force generated by the driving pulley 7 on the belt 8 is cumulatively increased, so the tension F2 of the belt 8 at point B is smaller than its tension F1 at point A , and the larger the cladding angle of the cladding arc on the entrance side, the greater the difference between F1 and F2, which causes the belt 8 on the side of point B to be in a slack state all the time, while the belt on the side of point A is in a loose state. 8 is always under tension.

In the same way, as shown in Figure 7, during the rolling process, the strip foil 5 enters the roll gap from the left side, the neutral point P is in the rolling arc, and on the left side of the neutral point P, the line of the roll surface of the work roll The speed is greater than the linear speed of the belt foil 5 entering the roll gap, which produces a speed difference and friction force F3, that is, the lower work roll 2 drives the belt foil 5 to rotate along the wrapping arc on the entry side, just like the belt 8 drives. In the figure, a volume element 9 is arbitrarily selected on the cladding arc on the inlet side. Due to the action of friction force F3, the proximal tension F2 acting on this volume element 9 is smaller than its distal tension F1. The proximal tension and distal tension expressed here are Tension is relative to the distance from the roll gap. For the next volume unit 9 on the right side of the volume unit 9, due to the cumulative increase of the friction force F3, the magnitude of the distal tension acting on this volume unit 9 is equal to F2, and the magnitude of its proximal tension is less than F2, and so on. From this, it can be concluded that the frictional force F3 increases cumulatively from point A (the starting point of the cladding arc on the inlet side) to point B (the end point of the cladding arc on the inlet side), correspondingly, the amount of the belt foil 5 on the volume unit 9 increases. The proximal tension F2 received gradually decreases from point A to point B.

As shown in FIG. 8 , a volume unit 9 is arbitrarily taken from the tape foil 5 . Due to the unevenness of tension, the tension on both sides of the volume unit 9C and D is greater than the tension in the middle E part, and the E part rises to form ripples. When the belt foil 5 is suspended and tensioned, the proximal tension F2 is equal to the distal tension F1. At this time, the volume unit 9 shrinks inward in the width direction, and its internal force F4 is negative.

As shown in FIG. 9 , when the volume unit 9 enters the cladding arc on the inlet side, the lower work roll 2 applies a backing force T to it, so that the volume unit 9 is bent and deformed. As the proximal tension F2 gradually decreases, the internal force F4 acting on the width direction of the volume unit 9 changes from negative to positive and gradually increases. The increase of the internal force F4 causes the volume unit 9 to expand outward in the width direction, just like a loose elastic band widens in the width direction, thereby flattening the corrugated portion of the belt foil 5 . During the flattening process, the proximal tension acting on the two sides of the volume unit 9C and D is rapidly reduced, and the two sides of C and D are extended outward in the width direction, so that the middle E part is in contact with the roll surface of the lower work roll 2 , After the E part is in contact with the lower work roll 2 , the proximal tension of the middle part of the volume unit 9 is correspondingly increased, thereby realizing the uniform distribution of the proximal tension F2 on the cross section of the volume unit 9 . It can be seen from Figure 6 that the proximal tension F2 in the roll gap calendering zone is the pre-rolling tension, where the pre-tension is the smallest, and the pre-tension distributed on the cross-section here is the most uniform. It can also be known that the larger the cladding angle of the cladding arc on the inlet side, the smaller the front tension in the calendering area of the roll gap, and the more uniform the front tension is distributed.

In rolling, the larger front tension is beneficial to the control of the flat shape. The existence of the cladding arc on the entrance side makes the front tension evenly distributed on the cross section of the belt foil 5, but part of the front tension is lost, so the coiler or the flattening roller 3 needs to increase the appropriate front tension to the belt foil 5 to compensation for losses. During rolling, the tension at the front end of the cladding arc on the inlet side can be increased to 50-60% of the yield strength of the material, and the strip foil 5 can be thinned by taking full advantage of the thinning effect of the tension on the strip foil 5 . For the rolling of the strip foil 5, it is basically seamless rolling. The rolling process of the strip foil 5 by the work rolls can be regarded as the repeated thinning and widening process of the strip foil 5. The coiler and the flattening roll 3 can be regarded as a process of repeated stretching and narrowing of the tape foil 5, so appropriately increasing the front tension of the tape foil 5 is more conducive to the thinning of the tape foil 5 and the control of the plate shape.

It should be noted that the proximal tension F2 changes in a gradient in the thickness direction. As shown in Figure 10, the side of the cladding arc on the entrance side that is in contact with the lower work roll 2 has a small tension and is far away from the lower work roll 2. , its tension is large, which compensates the loss of front tension to a certain extent, especially for thicker strips, the compensation effect is more obvious.

As shown in Figure 11, the shaded part in the figure is the deformation area. When the belt foil 5 enters the deformation zone of the roll gap, the belt foil 5 is squeezed by the work rolls and begins to deform. Due to the existence of the cladding arc on the entrance side, the deformation amount of the upper layer of the belt foil 5 is greater than that of the lower layer, and the particle point of the upper plate surface is at The linear velocity at the neutral point P is consistent with the linear velocity of the upper work roll 1 roll surface, while the lower plate surface lags, the linear velocity of the particle at point E is consistent with the linear velocity of the lower work roll 2 roll surface, resulting in The outflow speed of the upper layer of the belt foil 5 is greater than that of the lower layer of the belt foil 5, and the belt foil 5 is curled to the side of the lower work roll 2, which indicates that there is a layer shift phenomenon in the calendering area. The delamination phenomenon causes the neutral surface of the tape foil 5 to deviate to the lower layer, and causes the tape foil 5 to curl and deform. The curling deformation is more obvious on strips with larger plate thickness, but it is not obvious on foils with a thickness of less than 0.15mm, which can be corrected by subsequent processes such as flattening and straightening.

The offset of the neutral plane will cause uneven mechanical properties of the foil. It can be seen from the background technology that it is difficult to achieve the stability of the neutral plane in actual production. Since it is difficult to achieve, there is no need to comply with the national standard. requirements to specify the way the strip foil enters the roll gap. For some application fields, the requirements for the mechanical properties of the foil are not high, such as the use of copper foil for electrical conduction, or for decoration, anti-corrosion, etc., it is absolutely unnecessary to make the uniformity of the mechanical properties of the foil too high. requirements. Therefore, in the present invention, the strip foil 5 does not enter the roll gap horizontally along the rolling center line 6, which itself has broken the knowledge in the industry, and thus is creative.

It can be seen from FIG. 11 that the roll diameter of the upper work roll 1 is small, and the amount of indentation to the strip foil 5 is large, which is particularly beneficial to the thinning of the strip foil 5 and can reduce the total number of rolling passes. The tendency to bend is large, which is not conducive to bringing the lubricating medium into the roll gap evenly. The lower work roll 2 has a small lateral bending tendency, which is conducive to uniformly bringing the lubricating medium into the roll gap, and the superimposed wrapping arc has an equalizing effect on the belt foil 5, so that the belt foil 5 can obtain a better shape, but the lower The roll diameter of the work roll 2 is large, and the pressing amount to the strip foil 5 is small, which is not conducive to the thinning of the strip foil 5 . This embodiment combines the advantages of large-diameter work rolls and small-diameter work rolls: compared with the traditional work rolls with the same diameter as the upper work roll 1, the increase in the roll diameter of the lower work roll 2 is conducive to obtaining a better plate Compared with the traditional work roll with the same diameter as the lower work roll 2, the reduction of the roll diameter of the upper work roll 1 increases the pressing amount of the strip foil 5, which is beneficial to the thinning of the strip foil 5. Correspondingly, this embodiment also concentrates the shortcomings of the large-diameter work rolls and the small-diameter work rolls: compared with the traditional work rolls with the same diameter as the upper work roll 1, the increase in the roll diameter of the lower work roll 2 is not conducive to Thinning of strip foil 5. Compared with the traditional work roll with the same diameter as the lower work roll 2, the reduction of the roll diameter of the upper work roll 1 is not conducive to obtaining a better plate shape. It can be said that the advantages and disadvantages of large-diameter work rolls and small-diameter work rolls are a set of irreconcilable contradictions.

The three basic conditions for stable rolling of a rolling mill are roll accuracy, lubrication conditions and tension accuracy. In the case that the accuracy of the roll system and the tension accuracy cannot be further improved, improving the lubrication conditions plays a crucial role in the stability of the plate shape. As can be seen from Fig. 11, the lubrication condition is related to the size of the bite angle. At the entrance of the deformation zone, the bite angle of the lower work roll 2 is small, and the wedge-shaped gap formed with the lower plate surface of the belt foil 5 is more conducive to the entry of lubricating oil, resulting in an oil wedge effect and establishing a stable bearing capacity. In addition, the lower rolling arc length is longer, the contact surface is large, and the arc length fluctuation along the width direction of the foil is small, all of which are beneficial to the stability of the plate shape. Compared with the lower work roll 2, although the wedge-shaped gap formed between the upper work roll 1 and the upper plate surface of the belt foil 5 is not conducive to establishing a stable bearing capacity, the stability of the lower plate plate shape of the belt foil 5 has a restraining effect on the upper plate surface. It is beneficial to the stability of the plate shape as a whole. To sum up, the main contribution of the small diameter work rolls is to reduce the thickness of the belt foil, while the main contribution of the large diameter work rolls is to stabilize the overall shape of the belt foil and reduce the occurrence of defects such as waves and wrinkles. In general, although a small amount of thinning is sacrificed, it is beneficial to the stability of the overall plate shape.

For ultra-thin strip foils with a thickness of 0.01mm and below, it is basically negative roll gap rolling, and the reduction amount no longer plays a decisive role. Coupled with the rebound of the deformation zone, the existing equal-diameter work rolls with larger roll diameters can no longer effectively achieve thinning of the belt foil, and only work rolls with smaller roll diameters can be used. However, if the existing equal-diameter work rolls with smaller roll diameters are used, the rolling width of the strip foil cannot be achieved, and the rolling width will cause sheet surface defects, which is the current bottleneck restricting the rolling of high-precision wide strip foils. It is well known in the industry that the thinner the strip foil, the more difficult to control the rolled shape. At present, in order to break through the limit, the industry is doing everything possible, but no effective solution has been found. The significance of using unequal diameter work rolls in the present invention is that although a part of the thinning of the strip foil is sacrificed and the rolling passes (the number of reciprocating rolling) are slightly increased, the important thing is to keep the shape of the strip stable, The occurrence of rolling defects caused by the increase of the width is avoided or reduced, which is of great significance for the high-precision rolling of wide-width strip foils.

It can be seen from Example 1 that the present invention makes the belt foil 5 form an entrance side covering arc on the lower work roll 2 at the entrance side of the roll gap, and through the back support of the belt foil 5 by the lower work roll 2, the tension is wrapped on the entrance side. The cross-section of the covered arc is evenly distributed, which realizes the uniform rolling of the strip foil 5, breaks through the bottleneck restricting the development of the strip foil 5 in the direction of wider, thinner and more ideal shape, and solves the problem in the industry for a long time. It is a difficult technical problem to solve, so it has great application value and economic value. The invention adopts a rolling mill with unequal diameter work rolls to roll the strip foil, which is not only beneficial to the thinning of the strip foil, but also beneficial to obtain a better plate shape.

It should be noted that what causes the belt foil 5 to form the entry-side cladding arc on the lower work roll 2 is not limited to the flattening roll 3, but also includes all pre-machine rolls, such as S rolls, high and low rolls, or a combination thereof. As long as the adjustment roll in front of the machine closest to the roll gap is adjusted so that the strip foil 5 forms a certain angle with the rolling center line 6 before entering the roll gap, the strip foil 5 can form the entrance side coating on the lower work roll 2 arc. In this embodiment, the entry-side cladding arc is formed on the lower work roll 2 . Based on the same reason, the entry-side cladding arc may also be formed on the upper work roll 1 .

Example 2:

As shown in FIG. 12 , the difference between this embodiment and Embodiment 1 is that the strip foil 5 enters the roll gap horizontally along the rolling center line 6 , and a flattening roller 3 is arranged on the exit side of the roll gap. The roll surface is higher than the rolling center line 6 . The flattening roll 3 back-stretches the tape foil 5 so that the tape foil 5 forms an exit-side cladding arc on the roll surface of the upper work roll 1. Due to the existence of the cladding arc on the outlet side, the upper work roll 1 produces a back support for the belt foil 5, and the tension is evenly distributed on the cross-section of the cladding arc on the outlet side. The principle is as follows:

As shown in FIG. 13 , the tape foil 5 flowing out from the roll gap is wrapped around the upper work roll 1 to form a wrapping arc on the exit side. Since the linear velocity V of the belt foil 5 flowing out is greater than the linear velocity of the roll surface of the upper work roll 1, the upper work roll 1 generates a reverse friction force F4 on any volume unit 9 on the cladding arc on the exit side, and the volume unit 9 also generates a reverse friction force F4. There is a proximal tension F5 and a distal tension F6. According to the description in Embodiment 1, the friction force F4 increases gradually from point M to point N, and similarly, the distal tension F6 also increases accordingly. The distal tension F6 reaches the maximum at the N point, and the distal tension F6 here is the post tension. The post tension can not only prevent the strip foil 5 from deviating, but also can reduce the rolling pressure and facilitate the high-speed rolling of the strip foil 5 . Since the belt foil 5 flows out of the roll gap, its outflow linear velocity is greater than the linear velocity of the roll surface of the work roll, so the belt foil 5 can be understood as a belt, and the upper work roll 1 can be understood as a driven pulley, then, the belt foil 5 Drive the upper work roll 1 to rotate, just like the belt drives the driven pulley to rotate, the larger the cladding arc on the outlet side, the greater the transmission torque, thus reducing the torque of the upper work roll 1 and reducing the energy consumption of the main motor .

It is particularly important that after the belt foil 5 flows out of the roll gap, the back tension it receives gradually increases. Based on the mechanism in Example 1, the back tension is the smallest at the exit of the roll gap, and the cross section here is The post tension distribution is also the most uniform, which is important for the control of the strip shape. It can be seen from the discussion in the background art that only when the tension is evenly distributed on the cross section of the belt foil can the defects such as waves and wrinkles appear in the plate shape. The uniform distribution of tension at the exit of the roll gap is realized, and the generation of defects such as waves and wrinkles can be eliminated at the early stage of rolling with foil, so that a better plate shape can be obtained. As the volume unit 9 continues to flow out, the distal tension F6 acting on the cross section of the volume unit 9 gradually increases, and the uneven tension trend becomes obvious. The foil 5 is no longer suspended and shakes, and the plate shape is stabilized during the critical forming period of foil rolling, thereby preventing defects such as waves and wrinkles due to uneven tension of the plate shape.

It can be seen from Example 2 that in the present invention, at the exit side of the roll gap, the belt foil 5 forms an exit side cladding arc on the roll surface of the upper work roll 1, and realizes the uniformity of the back tension on the exit side cladding arc on the exit side. distribution, the generation of defects such as waves and wrinkles is eliminated at the critical early stage of strip foil rolling, and then through the back support of the strip foil 5 by the upper work roll 1, the plate shape of the strip foil 5 is formed in the rolling process. It can be stabilized in the later stage, so as to obtain a better plate shape. In addition, the torque of the upper work roll 1 is reduced, reducing the energy consumption of the rolling mill.

It should be noted that what causes the belt foil 5 to form the exit-side cladding arc on the upper work roll 1 is not limited to the flattening roll 3, but also includes all post-machine adjustment rolls, such as S rolls, high and low rolls, or a combination thereof . As long as the 2-machine rear adjustment roll closest to the roll gap is adjusted so that the strip foil 5 emerges from the roll gap and forms a certain angle with the rolling center line 6, the strip foil 5 can form the exit side on the upper work roll 1. Wrap Arc. In this embodiment, the cladding arc on the outlet side is formed on the upper work roll 1 , and based on the same reason, the cladding arc on the outlet side can also be formed on the lower work roll 2 .

Example 3:

This embodiment can be regarded as a combination of Embodiment 1 and Embodiment 2. As shown in FIG. 14 , the belt foil 5 forms an entrance-side cladding arc with the lower work roll 2 at the entrance side of the roll gap. The wrapping angle α is 30°; the belt foil 5 forms an exit-side wrapping arc with the upper work roll 1 at the exit side of the roll gap, and the wrapping angle β of the exit-side wrapping arc is also 30°. Due to the existence of the cladding arc on the inlet side and the cladding arc on the outlet side, the lower work roll 2 and the upper work roll 1 are respectively back-supported to the belt foil 5 .

The function and influence of the cladding arc on the inlet side in rolling have been described in Embodiment 1, and the function and influence of the cladding arc on the outlet side in rolling have been described in Embodiment 2, and will not be repeated here. It is worth noting that, as shown in Figure 13, on the exit side of the roll gap, the linear velocity of the lower layer of the volume unit 9 is greater than the linear velocity of the upper layer of the volume unit 9, and the friction force F4 acts on the upper plate surface of the volume unit 9, so that it can be It is concluded that the wrapping arc has a reverse straightening effect on the curling deformation of the tape foil 5 , which eliminates the curling effect of the tape foil 5 caused by the delamination phenomenon to a certain extent.

In the production of the strip foil 5, it is necessary to repeatedly roll the strip foil 5 for multiple passes. Due to the phenomenon of delamination, after each pass of rolling, the unidirectional curling deformation of the strip foil 5 will occur. Although the upper work roll 1 can reversely straighten the curling deformation, it is not enough to completely eliminate the curling deformation, so the rolling method needs to be improved.

11, 14, and 15, it can be seen that after the first pass of the strip foil 5 is rolled from left to right, the outflow speed of the upper layer of the strip foil 5 is greater than the outflow speed of the lower layer of the strip foil 5, and the strip foil 5 goes down to the work roll. 2 curled on one side. When the strip foil 5 completes the second pass rolling from right to left, the outflow speed of the upper layer of the strip foil 5 is lower than the outflow speed of the lower layer of the strip foil 5, and the strip foil 5 is curled up to the side of the work roll 1, so that the first pass The curl of the secondary roll is reverse corrected, and so on. It can be seen from the above that setting the total number of rolling passes of the strip foil 5 to an even number can eliminate the curling deformation of the strip foil 5 to the maximum extent.

It is especially important that after the first pass of rolling, the neutral plane of the strip foil 5 deviates from a certain side, then the second pass of rolling makes a reverse correction to the deviated neutral plane. After rolling with an even number of passes, the neutral plane is stabilized at the middle portion of the strip foil 5 , thereby ensuring the uniformity of the mechanical properties of the strip foil 5 . Through this method, the strict requirements for the rolling center line 6 in the national standard are bypassed, and the stability of the neutral plane of the strip foil 5 is realized in a real engineering manner, which solves the problems that cannot be solved in the prior art and Embodiment 1. technical difficulties.

As shown in FIG. 4 , in traditional rolling, there is no speed difference in the speed of the strip foil 5 flowing out of the roll gap, and the thinning process can be regarded as extrusion, just like squeezing toothpaste. In the present invention, the speed of the belt foil 5 flowing out of the roll gap has a speed difference, and the thinning process of the belt foil 5 is more like the reverse rolling of the upper and lower layers of the belt foil 5, just like rolling with a rolling pin. cake. As shown in Fig. 16, during the repeated rolling and pressing process, the upper and lower layers of the belt foil 5 are not only squeezed by the roll gap, but also subjected to a relative tensile force, so that the upper and lower layers of the belt foil 5 are compressed. slip, ultimately reducing the thickness. This sliding thinning has the effect of extrusion thinning and rolling thinning. Compared with the traditional extrusion thinning, the plate shape is better and it is easier to control the plate shape.

It can be seen from Example 3 that the present invention better solves the problem of curling and deformation of the belt foil 5, and it is particularly important that the slip thinning of the present invention has both the effect of extrusion thinning and the effect of rolling thinning. , and the neutral plane is stabilized at the middle portion of the tape foil 5 , thereby ensuring the uniformity of the mechanical properties of the tape foil 5 . The invention breaks through the strict requirements on the rolling center line in the national standard, realizes the stability of the neutral plane in a real engineering manner, and solves the technical problems that cannot be solved by the prior art.

In Example 3, the cladding arc on the outlet side reduces the torque of the upper work roll 1, but the cladding arc on the inlet side increases the torque of the lower work roll 2, resulting in the difference in the driving torque of the upper and lower work rolls, which will increase the torque of the upper and lower work rolls. The overall energy consumption of the large rolling mill. To this end, continue to improve technical solutions:

Example 4:

As shown in FIG. 17 , the present embodiment differs from Embodiment 3 in that both the entry-side cladding arc and the exit-side cladding arc are formed on the lower work roll 2 . It can be seen from Fig. 17 that the cladding arc on the inlet side increases the torque of the lower work roll 2, while the cladding arc on the outlet side reduces the torque of the lower work roll 2. Therefore, the driving torque applied to the lower work roll 2 is not as a whole. Change.

As shown in Fig. 18, since the roll diameter of the upper work roll 1 is smaller than that of the lower work roll 2, both the cladding arc on the entrance side and the cladding arc on the exit side are formed on the lower work roll 2, so that the upper work roll 1 has a negative effect on the belt foil. The thinning effect of 5 is the largest. However, the disadvantage of this construction is that, due to the superposition effect, the unidirectional crimping deformation of the tape foil 5 is greater than in the above-described embodiment. In order to overcome this shortcoming, the solution is to turn over the strip foil 5 before each pass of rolling, and then send the strip foil 5 into the roll gap for rolling. In this way, the curling deformation of the strip foil 5 during the previous pass rolling can be eliminated by the reverse rolling. The difference between the rollover rolling and the existing rolling is that in two adjacent passes of rolling, the sheet surfaces of the strip foil 5 rolled by the upper work roll 1 and the lower work roll 2 are different. In order to ensure the consistency of the properties of the upper and lower plate surfaces of the strip foil 5, similarly, the total number of rolling passes of the strip foil 5 is set to an even number.

After adopting the above method, on the one hand, the torques of the upper and lower work rolls are balanced, and on the other hand, the curling deformation of the strip foil 5 during rolling is eliminated. It is especially worth noting that due to the rollover, the contact length and force between the upper and lower plate surfaces of the belt foil 5 and the upper and lower work rolls are the same, so the problem of different brightness of the upper and lower plate surfaces of the belt foil 5 is unexpectedly solved. , which is also a problem that cannot be solved in the above-mentioned embodiments.

It should be noted that the above-mentioned embodiments all take the rolling of a strip with a thickness of 0.01 mm as an example, which does not prevent the present invention from being able to roll a thicker strip, and the principles and functions are the same.

Parts not described in detail are prior art. Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, and substitutions can be made in these embodiments without departing from the principle and spirit of the invention and modifications, the scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

A rolling method of wide metal strip foil is characterized in that: a rolling mill with unequal diameter work rolls is used, and the roll diameter of a certain work roll of the rolling mill is larger than that of another work roll; , so that the linear velocity of the roll surface of the two work rolls is the same, and at the entrance or exit side of the roll gap formed by the two work rolls, the metal strip foil is wrapped on the roll surface of a certain work roll to form a wrapping arc. The backing of the work roll to the metal strip foil makes the tension evenly distributed across the cross section of the cladding arc.
The rolling method of a wide-width metal strip foil according to claim 1, wherein the metal strip foil is wrapped on the roll surface of the work roll with a larger roll diameter to form a wrapping arc.
The rolling method of a wide metal strip foil according to claim 1, wherein the cladding arc is obtained by changing the angle at which the metal strip foil enters or exits the roll gap.
The rolling method of a wide metal strip foil according to claim 1, wherein the cladding angle of the cladding arc is α, and 0°<α≤90°.
The rolling method of a wide-width metal strip foil according to claim 1, characterized in that: on the inlet side and the outlet side of the roll gap, the metal strip foil is wrapped on the roll surface of the same or different work rolls, An inlet-side cladding arc and an outlet-side cladding arc are formed.
The rolling method of a wide-width metal strip foil according to claim 5, wherein the metal strip foil is wrapped on the roll surface of the work roll with a larger roll diameter.
The rolling method of a wide metal strip foil according to claim 5, wherein the cladding arc on the inlet side is obtained by changing the angle at which the metal strip enters the roll gap, and the cladding arc on the outlet side is obtained by changing the angle of the metal strip foil entering the roll gap. The metal strip foil is obtained from the angle of outflow from the roll gap.
The rolling method of a wide-width metal strip foil according to claim 1, wherein the roll diameter of the work roll with the larger roll diameter is 1.5-5 times the roll diameter of the work roll with the smaller roll diameter.
The rolling method of a wide-width metal strip foil according to any one of claims 1-8, characterized in that: before the next pass of rolling, the metal strip foil is turned over, and then enters a rolling mill for rolling .
The rolling method of a wide metal strip and foil according to claim 9, wherein the total number of rolling passes of the metal strip and foil is an even number.