A method for controlling roller marks on the surface of cold-rolled copper strip

Abstract

The invention belongs to the technical field of cold-rolled steel strip, and specifically relates to a method for controlling roller marks on the surface of a cold-rolled copper strip, comprising: after the roller system is pressed and the roller gap is cleared, before the roller gap is opened, the bending roller force of the working roller and the intermediate roller is switched to 80% of the maximum bending roller force, and then the roller gap opening operation is performed; in the process of closing the roller gap of the strip: pressing down the oil cylinder for fast pressing until the distance between the working roller and the strip surface is less than 0.5 mm, and then switching to slow pressing; after the working roller contacts the strip surface, when the rolling force rises to 100 tons, pressing down the oil cylinder to stop the action; switching the bending roller force of the working roller and the intermediate roller to the bending roller force required by the production process table; establishing the first-stage tension of the strip, and the rolling force increases from 100 tons to the rolling force required by the production process table; in the starting stage, establishing the second-stage tension of the strip to the tension required by the production process table, and performing normal rolling. The technical solution of the invention provides a method for avoiding roller marks during the entire cold-rolled copper strip production process.

Description

Technical Field

[0001] The invention belongs to the technical field of cold-rolled strip steel, and in particular relates to a method for controlling roller marks on the surface of a cold-rolled copper strip. Background Art

[0002] The surface quality requirements of cold-rolled high-end copper foil and copper strip products are strict, and the roller marks on the surface of the rolled products seriously affect the improvement of product quality. The finished products after rolling have continuous or intermittent roller marks along the width direction of the strip, and there will be multiple roller marks along the length direction of the strip. After tracking, it was found that the roller marks in the width direction appear periodically in the length direction of the strip, and the marks on the rollers and the marks on the strip are consistent in shape and brightness. Therefore, it is necessary to find a way to avoid marks on the roller surface and the surface of the strip.

[0003] Since the surface roughness of the rollers used to produce high-end copper foil and copper strip reaches 0.05μm, the roller surface is as bright as a mirror. The contact between the rollers and the contact between the rollers and the strip will cause a significant change in the roughness of the roller surface in the contact area. The surface roughness of the area where contact is generated and the area where no contact is generated on the roller surface is obviously different. The "roller mark" on the roller surface can be seen from the appearance, and then it is printed on the surface of the strip.

[0004] It is found from public data that the previous understanding of this problem is limited to: after replacing the rolls, during the pressing process, the contact between the rolls in a stationary (non-rotating) state causes roll marks. Therefore, the purpose of eliminating roll marks is to keep the working rolls rotating during the pressing process.

[0005] However, it was found during production that the products produced by the above method in the rolling mill still had roller marks on the surface. When the copper coil was shone with side light, it could be observed that the roller marks were still obvious. This surface quality defect could not meet the quality requirements of IC frame copper alloy strips. Summary of the invention

[0006] In the cold-rolled copper strip production process, there are many rollers, and the contact and separation process between the rollers, as well as the contact and separation process between the working rollers and the copper strip, are likely to produce roller mark defects. Ignoring any of these links will lead to roller mark defects. In order to overcome the above technical problems, the purpose of the present invention is to provide a method for avoiding roller marks in the entire cold-rolled copper strip production process.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0008] A method for controlling roller marks on the surface of a cold-rolled copper strip, the method comprising:

[0009] S1, after the roller system is pressed against each other and the roller gap is cleared, the method of not producing roller marks during the roller gap opening process:

[0010] After the roll system is pressed against and the roll gap is cleared, before the roll gap is opened, the bending roll force of the upper working roll and the upper intermediate roll is switched to 80% of the maximum bending roll force, and the bending roll force of the lower working roll and the lower intermediate roll is switched to 80% of the maximum bending roll force, and then the roll gap opening operation is performed;

[0011] S2, a method for preventing roller marks from being produced during the strip closing roll gap process:

[0012] Press down the oil cylinder to press quickly until the upper working roll is less than 0.5mm from the strip surface, then switch to slow pressing, the slow pressing speed is 10% of the fast pressing speed;

[0013] After the upper working roll contacts the strip surface, when the rolling force rises to 100 tons, the oil cylinder is pressed down to stop the action;

[0014] Switch the bending force of the upper working roll and the upper intermediate roll to the bending force required by the production process table, and switch the bending force of the lower working roll and the lower intermediate roll to the bending force required by the production process table;

[0015] S3, a method for establishing the first-stage tension of the strip, in which no roller mark is produced during the process of increasing the current 100-ton rolling force to the rolling force required by the production process table:

[0016] First, establish a stage of tension before and after the strip. The stage of tension is 1 / 3 of the tension required by the production process table. Slowly press down the pressing cylinder to increase the rolling force from 100 tons to the rolling force required by the production process table.

[0017] S4, the start-up phase, establishes the second-stage tension of the strip to the tension required by the production process table, and performs normal rolling.

[0018] Furthermore, before S1, the method further includes:

[0019] S0, when the roll system is pressed against each other and the roll gap is cleared, the speed of the upper working roll moving downward is reduced to the minimum speed.

[0020] Furthermore, before S0, the method further includes:

[0021] After the roll change is completed, during the rising process of the rolling line adjustment device, the rising speed of the rolling line adjustment device is reduced to the minimum speed.

[0022] Furthermore, after S1 and before S2, the method further includes:

[0023] After the roll gap opening operation is completed, the belt is threaded, and the threading speed is consistent with the roller line rotation speed.

[0024] Furthermore, after S4, the method further includes:

[0025] S5, after the rolling mill stops, the rolling mill is withdrawn in two stages:

[0026] In the first stage, the front and rear tension of the strip is reduced to 1 / 3 of the tension required by the production process table, the rolling force is adjusted to 100 tons, the bending force of the upper working roll and the upper intermediate roll is switched to 80% of the maximum bending force, and the bending force of the lower working roll and the lower intermediate roll is switched to 80% of the maximum bending force;

[0027] In the second phase, all the positions will be withdrawn.

[0028] Furthermore, after S5, the method further includes:

[0029] S6, when opening the roll gap, press down the oil cylinder to slow lifting speed until the upper working roll is at least 0.5mm away from the strip surface, then switch to fast lifting speed until the roll gap is fully opened. The slow lifting speed is 10% of the fast lifting speed.

[0030] The present invention adopts the above technical solution, which has the following advantages:

[0031] 1. This method covers the method of controlling roller marks in the entire cold-rolled copper strip production process, and has a good control effect.

[0032] 2. In this method, the rolling force and bending roll force have reached the process required values ​​before starting, the plate shape and thickness of the strip head can quickly meet the finished product requirements, and the yield rate is high.

[0033] 3. In the process of closing the roller gap, the speed of this method is slow pressing and fast pressing, and in the process of opening the roller gap, the speed is slow lifting and fast lifting. In the process of controlling the roller printing, it not only simply reduces the action speed of the pressing cylinder, but also improves the production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the structure of a six-roller cold rolling mill;

[0035] In the figure: 1 pressing cylinder, 2 upper support roll, 3 upper intermediate roll, 4 upper working roll, 5 lower working roll, 6 lower intermediate roll, 7 lower support roll, 8 upper support roll balancing cylinder, 9 upper intermediate roll bending cylinder, 10 upper working roll bending cylinder, 11 lower working roll bending cylinder, 12 lower intermediate roll bending cylinder, 13 rolling line adjustment device;

[0036] Figure 2 The present invention is a flow chart of a method for controlling roller marks on the surface of cold-rolled copper strip products. DETAILED DESCRIPTION

[0037] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and specific implementation methods.

[0038] An embodiment of the present invention provides a method for controlling the roller mark on the surface of a cold-rolled copper strip. The roller mark is controlled during the entire copper strip cold rolling production process, and the contact force state between the rollers and the contact force state between the rollers and the strip is changed and controlled, that is, all factors that cause a significant change in the surface roughness of the rollers are controlled.

[0039] Implementation case 1: For a six-high rolling mill:

[0040] Reference Figure 1 It is a schematic diagram of a six-roll rolling mill, including: a pressing cylinder 1, an upper supporting roll 2, an upper intermediate roll 3, an upper working roll 4, a lower working roll 5, a lower intermediate roll 6, a lower supporting roll 7, an upper supporting roll balancing cylinder 8, an upper intermediate roll bending cylinder 9, an upper working roll bending cylinder 10, a lower working roll bending cylinder 11, a lower intermediate roll bending cylinder 12, and a rolling line adjustment device 13.

[0041] In the entire copper strip cold rolling production process, the generation of roller marks is controlled, the contact force state between the rollers and the contact force state between the rollers and the strip is changed and controlled, that is, all factors that cause significant changes in the surface roughness of the rollers are controlled. There are nine key processes in total: ① After the roll change is completed, during the rising process of the rolling line adjustment device, a method for controlling the lower working roll, the lower intermediate roll and the lower support roll to prevent roll marks from being generated; ② During the process of roller system pressing and roll gap clearing, the rolls approach each other and the roll gap is closed. A method for controlling the roll marks not to be generated during the process; ③ During the process of opening the roll gap, the rolls move away from each other and the roll gap is opened. A method for controlling the roll marks not to be generated during the process of threading the strip; ⑤ A method for controlling the roll marks not to be generated during the process of closing the roll gap with the strip; ⑥ A method for controlling the roll marks not to be generated after the first-stage tension process of the strip is established and the rolling force is increased to the starting rolling force; ⑦ During the starting stage, the second-stage tension of the strip is established to the tension required by the production process table, and a method for controlling the roll marks not to be generated during this stage; ⑧ During the parking stage, a method for controlling the roll marks not to be generated; ⑨ After parking, a method for controlling the roll marks not to be generated during the roll gap opening stage.

[0042] Referring to Figure 2, the purpose and methods of nine key processes are described as follows:

[0043] ① Reduce the rising speed of the rolling line adjustment device to the minimum speed to reduce the impact of the lower support roll inertia on the lower intermediate roll and the lower working roll causing roll marks.

[0044] ② When the roller system is pressed against and the roller gap is cleared, there is inertia and impact force when the upper and lower working rollers contact each other, causing roller marks. The speed of the upper working roller moving downward is reduced to the minimum speed to reduce the inertia and impact of the upper working roller, thereby achieving the purpose of eliminating roller marks.

[0045] ③ After the roller system is pressed and the roller gap is cleared, before the roller gap is opened, the bending force of the upper working roller and the upper intermediate roller is switched to 80% of the maximum bending force, and the bending force of the lower working roller and the lower intermediate roller is switched to 80% of the maximum bending force. This is to make the upper three rollers fit closely together, and the lower three rollers fit closely together; eliminate the gap between the roller bearings and the bearing seats, and maintain a certain prestress between the rollers. In order to avoid repeated contact, separation, impact and friction between the rollers during the process of opening and closing the roller gap, the above gap will cause roller marks on the roller surface, and then the roller gap opening operation will be carried out (the roll gap opening operation means that the upper three rollers move upward at the same time, and the lower three rollers remain stationary).

[0046] ④ After the roll gap operation is completed, the strip is threaded. During the threading process, the strip will rub against the working roll surface, causing local roughness changes on the roll surface, which will also be printed on the strip surface during rolling. Therefore, ensuring that the threading speed is consistent with the rolling speed of the roll line can minimize the friction between the strip and the roll surface.

[0047] ⑤ After the strip is threaded, the strip is closed. During the closing of the roll gap (the closing of the roll gap means that the three upper rolls move downward at the same time, and the three lower rolls remain stationary), when the working rolls are pressed quickly on the strip, impact will occur, causing roll marks; at the same time, during the closing of the roll gap, when the rolling force of the working rolls on the strip is too large, it will also cause roll marks. Therefore, press the cylinder quickly until the upper working roll is about to touch the strip (when the upper working roll is less than 0.5mm from the strip surface), and then switch to slow pressing (the slow pressing speed is 10% of the fast pressing speed). After the upper working roll touches the strip surface, the rolling force rises to 100 tons, and the cylinder is pressed down to stop (100 tons of rolling force is less than the rolling force required by the production process table, but in order to avoid excessive rolling force of the working rolls on the strip causing roll marks, it is set to 100 tons). After closing the roll gap, since the rolling force between the rolls has reached 100 tons, it is no longer necessary to use the large bending roll force of the working roll and the intermediate roll as the prestress between the rolls; and when the rolling force is 100 tons, switching the bending roll force will not cause impact between the rolls. Therefore, the bending roll force can be switched to the bending roll force required by the production process table at this time.

[0048] ⑥ Strip tensioning. Since the strip is tensioned in one step, that is, a large tension is directly applied to the strip, the strip undergoes a large elastic deformation relative to the working roll, and the friction between the strip and the working roll will cause roller marks on the strip surface. To solve this problem, two-stage tensioning is required. First, a small tension is established before and after the strip. The tension is 1 / 3 of the tension required by the production process table. Since the strip has a certain tension as prestress, the effect of the change in rolling force on the roughness of the roller surface is suppressed, and the problem of "roller marks will also be caused when the working roll acts on the strip with too large a rolling force" will not occur. At this time, the pressing cylinder can be slowly pressed down, increasing from 100 tons to the rolling force required by the production process table.

[0049] ⑦ After the rolling mill starts (rolling mill starts means the rolls start to rotate), the tension is built up in the second stage. The front and rear tension of the strip is quickly increased to the tension required by the production process table, and normal rolling (normal rolling force, tension, bending roll force) is carried out. At the same time, the working rolls are rotating after the mill starts, and the change in tension will not cause roll marks on the working rolls.

[0050] ⑧ After the rolling mill stops, the same principle is followed to remove the tension in two stages. In the first stage, the front and rear tension of the strip is reduced to 1 / 3 of the tension required by the production process table. The rolling force is adjusted to 100 tons. The bending force of the working roll and the intermediate roll is switched to 80% of the maximum bending force. In the second stage, all the tension is removed.

[0051] ⑨ When opening the roll gap, the same principle is used, pressing down the oil cylinder to slow lifting speed until the working roll leaves the strip surface, then switching to fast lifting speed until the roll gap is fully opened.

[0052] Implementation Case 2: For a four-roll mill or a skin-pass mill, the difference from a six-roll mill is that there is no need for an intermediate roll and an intermediate roll bending device, and the remaining steps are the same as those of Implementation Case 1.

[0053] In addition, extracting several processes from the 9 key processes of the technical solution and combining them can achieve a certain roller printing control effect. The best effect is achieved when all 9 key processes are controlled.

[0054] The present invention adopts the above technical scheme and has the following advantages: 1. This method covers the method of controlling the roller mark during the entire cold-rolled copper strip production process, and the control effect is good. 2. In this method, the rolling force and the bending roll force have reached the process required values ​​before starting the machine, and the plate shape and thickness of the strip head can quickly meet the finished product requirements, and the yield rate is high. 3. In the process of closing the roll gap, the speed of this method has slow pressing and fast pressing, and in the process of opening the roll gap, the speed has slow lifting and fast lifting. In the process of controlling the roller mark, it not only simply reduces the action speed of the pressing cylinder, but also improves the production efficiency.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for controlling the roller mark on the surface of a cold-rolled copper strip, characterized in that: The method comprises: S1, after the roller system is pressed against each other and the roller gap is cleared, the method of not generating roller marks during the roller gap opening process: After the roll system is pressed against and the roll gap is cleared, before the roll gap is opened, the bending roll force of the upper working roll and the upper intermediate roll is switched to 80% of the maximum bending roll force, and the bending roll force of the lower working roll and the lower intermediate roll is switched to 80% of the maximum bending roll force, and then the roll gap opening operation is performed; S2, a method for preventing roller marks from being produced during the strip closing roll gap process: Press down the oil cylinder to press quickly until the upper working roll is less than 0.5mm from the strip surface, then switch to slow pressing, the slow pressing speed is 10% of the fast pressing speed; After the upper working roll contacts the strip surface, when the rolling force rises to 100 tons, the oil cylinder is pressed down to stop the action; Switch the bending force of the upper working roll and the upper intermediate roll to the bending force required by the production process table, and switch the bending force of the lower working roll and the lower intermediate roll to the bending force required by the production process table; S3, a method for establishing the first-stage tension of the strip, in which no roller mark is produced during the process of increasing the current 100-ton rolling force to the rolling force required by the production process table: First, establish a stage of tension before and after the strip. The stage of tension is 1 / 3 of the tension required by the production process table. Slowly press down the pressing cylinder to increase the rolling force from 100 tons to the rolling force required by the production process table. S4, the start-up phase, establishes the second-stage tension of the strip to the tension required by the production process table, and performs normal rolling; S5, after the rolling mill stops, the rolling mill is withdrawn in two stages: In the first stage, the front and rear tension of the strip is reduced to 1 / 3 of the tension required by the production process table, the rolling force is adjusted to 100 tons, the bending force of the upper working roll and the upper intermediate roll is switched to 80% of the maximum bending force, and the bending force of the lower working roll and the lower intermediate roll is switched to 80% of the maximum bending force; In the second phase, all the positions will be withdrawn.

2. A method for controlling the roller mark on the surface of a cold-rolled copper strip according to claim 1, characterized in that: Before S1, the method further includes: S0, when the roll system is pressed against each other and the roll gap is cleared, the speed of the upper working roll moving downward is reduced to the minimum speed.

3. A method for controlling the roller mark on the surface of a cold-rolled copper strip according to claim 2, characterized in that: Before S0, the method further includes: After the roll change is completed, during the rising process of the rolling line adjustment device, the rising speed of the rolling line adjustment device is reduced to the minimum speed.

4. A method for controlling the roller mark on the surface of a cold-rolled copper strip according to claim 1, characterized in that: After S1 and before S2, the method further includes: After the roll gap opening operation is completed, the belt is threaded, and the threading speed is consistent with the rotation speed of the roll line.

5. A method for controlling the roller mark on the surface of a cold-rolled copper strip according to claim 1, characterized in that: After S5, the method further includes: S6, when opening the roll gap, press down the oil cylinder to slow lifting speed until the upper working roll is at least 0.5mm away from the strip surface, then switch to fast lifting speed until the roll gap is fully opened. The slow lifting speed is 10% of the fast lifting speed.

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