Method for eliminating embossing marks on surface of cold-rolled strip

Abstract

The invention discloses a method for eliminating knurling marks on the surface of a cold-rolled strip, which comprises the following steps of: designing and optimizing convexity of a roller and a roller system: simulating and analyzing the convexity of the roller and the roller system at a cold-rolling mill and the convexity of a roller system of a supporting roller by utilizing finite element analysis, predicting the thermal deformation condition of the roller and the roller system in the rolling process, and calculating the knurling marks on the surface of the cold-rolled strip according to a simulation result. And the convexity design of the roller and the roller system is adjusted to reduce the thermal deformation amount in the rolling process, and convexity parameter values are determined through multiple times of iterative optimization. By optimizing grinding of the aluminum and aluminum alloy cold-rolling mill roller and the roller system and optimizing parameter values of the roller and the roller system convexity of the thermal deformation amount of the roller deformation area in the rolling process, the thermal deformation amount of the roller and the roller system in the aluminum plate strip rolling process is reduced, heat accumulation during thermal deformation of the aluminum plate strip can be effectively controlled, embossing marks are prevented, and the service life of the aluminum plate strip is prolonged. The lubricating oil which is high in strength and uniform in heat dissipation of the deformation area of the aluminum plate is designed, the lubricating effect is improved, heat of the deformation area of the aluminum plate cannot be gathered, and the probability that plate face embossing marks are generated is reduced.

Description

Technical Field

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

[0002] When the aluminum plate is rolled by the roller, the thermal convexity of the roller deformation zone is uneven, the lubrication effect of the rolling lubricant is poor, the heat in the aluminum plate deformation zone is unevenly dispersed, and the heat is concentrated in some local areas, resulting in irregular pattern marks with inconsistent color differences on the aluminum plate surface. Eliminating the uneven thermal convexity of the roller deformation zone and reducing the probability of heat accumulation in the aluminum plate deformation zone are the key process technologies to solve the embossing marks on the surface of cold-rolled strips;

[0003] At the same time, without affecting the normal rolling of the cold-rolled sheet, the roller and roller system convexity process can be appropriately adjusted to reduce the thermal deformation of the roller deformation zone. The strength and thickness of the rolling lubricant can be appropriately adjusted to reduce the probability of uneven heat dispersion in the deformation zone of the aluminum plate. To this end, we propose a method for eliminating embossing marks on the surface of cold-rolled strip. Summary of the invention

[0004] The object of the present invention is to provide a method for removing embossing marks on the surface of a cold-rolled strip to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for removing embossing marks on the surface of a cold-rolled strip, comprising the following specific steps:

[0006] Step 1: Design and optimization of the crown of the rolls and roll system: Use finite element analysis to simulate and analyze the crown of the rolls and roll system and the roll system of the support rolls at the cold rolling mill to predict their thermal deformation during the rolling process. According to the simulation results, adjust the crown design of the rolls and roll system to reduce the thermal deformation during rolling. Determine the crown parameter value through multiple iterative optimizations;

[0007] Step 2: Implementation of roller and roller system grinding technology: According to the optimized crown parameter value, prepare the corresponding grinding tools and equipment, use high-precision grinding equipment to accurately grind the roller and roller system to ensure that the crown meets the design requirements, and conduct quality inspection on the ground roller and roller system, including crown measurement, surface roughness detection, etc., to ensure that they meet the process requirements;

[0008] Step 3: Set up a cooling system for the rolls and roll system to cool them down, lower their temperature and reduce thermal deformation;

[0009] Step 4: Adjustment of rolling process parameters: According to the material and thickness of the aluminum strip, reasonably set the rolling speed to reduce the heat generated during the rolling process, and adjust the rolling pressure according to the crown design of the roller and the roller system to ensure that the aluminum strip is evenly stressed during the rolling process;

[0010] Step 5: Design of rolling lubricant: Select lubricant with high strength and high heat dissipation performance to meet the lubrication requirements during the rolling process of aluminum strip, and ensure that the lubricant can evenly and fully cover the rollers and the aluminum strip to reduce friction and heat generation;

[0011] Step 6: Rolling: Connect the lubricating oil to the spray system, and arrange the nozzles above the rollers to ensure that the lubricating oil can evenly and fully cover the rollers and the aluminum strip to reduce friction and heat generation, and then roll the aluminum and aluminum alloys.

[0012] Furthermore, the cold rolling work roll crown parameter value determined in step 1 is 0.03-0.05 mm.

[0013] Furthermore, the roughness of the working roll system after grinding in the step 2 is between 0.35-0.45 μm, and the roughness of the backup roll system is between 0.8-1.0 μm.

[0014] Furthermore, the cold rolling working rolls and support rolls select materials with high thermal stability and low thermal expansion coefficient as the base material of the rolling rolls and the roll system, such as one of alloy forged steel with added Cr, Ni, Si, infinitely chilled cast iron and tungsten steel, so as to further improve the thermal deformation resistance of the rolling rolls and the roll system.

[0015] Furthermore, the cooling system is a water cooling system inside the roller or an external air cooling system, which effectively reduces the temperature of the roller and the roller system and reduces the thermal deformation by precisely controlling the flow and temperature of the cooling water, or the wind speed and direction of the fan.

[0016] Furthermore, the rolling speed in step four is like 1235 type aluminum material with an average thickness of 3.12mm. In the biting stage, a lower rolling speed, such as between 0.5m / s-1m / s, is adopted to facilitate biting and avoid rolling cracking. In the intermediate rolling stage, a higher rolling speed is adopted to improve production efficiency. For example, when the thickness of the aluminum plate and strip is reduced to between 1mm-2mm, the rolling speed can be increased to 2m / s-5m / s. In the final rolling stage, due to the long contact time between the plate and the roller and the large temperature drop loss, in order to obtain uniform structure and performance, excellent surface quality and good plate shape, the rolling speed will be appropriately reduced and maintained between 1m / s-2m / s.

[0017] Furthermore, in the step five, the lubricating oil is based on synthetic oil or mineral oil, and aromatic hydrocarbons are added as thickeners and components to enhance the strength of the oil film. In order to increase the viscosity and lubricating properties of the lubricating oil, hydrocarbon compounds with longer carbon chains can be added. These compounds help to form a stable oil film and reduce the friction between the aluminum plate and the roller. Antioxidants, rust inhibitors, and extreme pressure anti-wear agents can be added in appropriate amounts as needed to improve the performance of the lubricating oil and extend its service life.

[0018] Furthermore, the usage ratio of the base oil, aromatic hydrocarbons, hydrocarbon compounds with a longer carbon chain, antioxidants, rust inhibitors and extreme pressure and anti-wear agents is 9:0.3:0.3:0.05:0.1:0.1.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. By optimizing the grinding of the rolls and roll systems of the aluminum and aluminum alloy cold rolling mill, optimizing the parameter values ​​of the rolls and roll system convexity of the roll deformation zone during rolling, reducing the thermal deformation of the rolls and roll system during the rolling process of the aluminum strip, the heat accumulation during the thermal deformation of the aluminum strip can be effectively controlled, and the generation of embossing marks can be prevented.

[0021] 2. The lubricant is designed to have high strength and uniform heat dissipation in the deformation area of ​​the aluminum plate, which improves the lubrication effect, prevents heat from accumulating in the deformation area of ​​the aluminum plate, and reduces the probability of embossing marks on the plate surface. DETAILED DESCRIPTION

[0022] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Example 1

[0024] A method for removing embossing marks on the surface of a cold-rolled strip comprises the following specific steps:

[0025] Step 1: Design and optimization of the crown of the rolls and roll system: Use finite element analysis to simulate and analyze the crown of the rolls and roll system and the roll system of the support rolls at the cold rolling mill to predict their thermal deformation during the rolling process. According to the simulation results, adjust the crown design of the rolls and roll system to reduce the thermal deformation during rolling. Determine the crown parameter value through multiple iterative optimizations;

[0026] Step 2: Implementation of roller and roller system grinding technology: According to the optimized crown parameter value, prepare the corresponding grinding tools and equipment, use high-precision grinding equipment to accurately grind the roller and roller system to ensure that the crown meets the design requirements, and conduct quality inspection on the ground roller and roller system, including crown measurement, surface roughness detection, etc., to ensure that they meet the process requirements;

[0027] Step 3: Set up a cooling system for the rolls and roll system to cool them down, lower their temperature and reduce thermal deformation;

[0028] Step 4: Adjustment of rolling process parameters: According to the material and thickness of the aluminum strip, reasonably set the rolling speed to reduce the heat generated during the rolling process, and adjust the rolling pressure according to the crown design of the roller and the roller system to ensure that the aluminum strip is evenly stressed during the rolling process;

[0029] Step 5: Design of rolling lubricant: Select lubricant with high strength and high heat dissipation performance to meet the lubrication requirements during the rolling process of aluminum strip, and ensure that the lubricant can evenly and fully cover the rollers and the aluminum strip to reduce friction and heat generation;

[0030] Step 6: Rolling: Connect the lubricating oil to the spray system, and arrange the nozzles above the rollers to ensure that the lubricating oil can evenly and fully cover the rollers and the aluminum strip to reduce friction and heat generation, and then roll the aluminum and aluminum alloys.

[0031] Among them, the cold rolling work roll crown parameter value determined in step one is 0.03mm.

[0032] Wherein, the roughness of the working roll system after grinding in the step 2 is 0.35 μm, and the roughness of the backup roll system is 0.8 μm.

[0033] Among them, the cold rolling working rolls and support rolls are selected from materials with high thermal stability and low thermal expansion coefficient as the base materials of the rolling rolls and the roll system, such as alloy forged steel with Cr, Ni, and Si added, so as to further improve the thermal deformation resistance of the rolling rolls and the roll system.

[0034] The cooling system is a water cooling system inside the roller or an external air cooling system, which can effectively reduce the temperature of the roller and roller system and reduce thermal deformation by precisely controlling the flow and temperature of the cooling water or the wind speed and direction of the fan.

[0035] Among them, the rolling speed in the step four is like 1235 type aluminum material, with an average thickness of 3.12mm. In the biting stage, a lower rolling speed, such as 0.5m / s, is adopted to facilitate biting and avoid rolling cracking. In the intermediate rolling stage, a higher rolling speed is adopted to improve production efficiency. For example, when the thickness of the aluminum plate and strip is reduced to 1mm, the rolling speed can be increased to 2m / s. In the final rolling stage, due to the long contact time between the plate and the roller and the large temperature drop loss, in order to obtain uniform structure and performance, excellent surface quality and good plate shape, the rolling speed will be appropriately reduced and maintained at 1m / s.

[0036] Among them, the lubricating oil in step five is based on synthetic oil or mineral oil, and aromatic hydrocarbons are added as thickeners and components to enhance the strength of the oil film. In order to increase the viscosity and lubricating properties of the lubricating oil, hydrocarbon compounds with longer carbon chains can be added. These compounds help to form a stable oil film and reduce the friction between the aluminum plate and the roller. Antioxidants, rust inhibitors, and extreme pressure anti-wear agents can be added in appropriate amounts as needed to improve the performance of the lubricating oil and extend its service life.

[0037] The usage ratio of the base oil, aromatic hydrocarbons, hydrocarbon compounds with a longer carbon chain, antioxidants, rust inhibitors and extreme pressure and anti-wear agents is 9:0.3:0.3:0.05:0.1:0.1.

[0038] Example 2

[0039] A method for removing embossing marks on the surface of a cold-rolled strip comprises the following specific steps:

[0040] Step 1: Design and optimization of the crown of the rolls and roll system: Use finite element analysis to simulate and analyze the crown of the rolls and roll system and the roll system of the support rolls at the cold rolling mill to predict their thermal deformation during the rolling process. According to the simulation results, adjust the crown design of the rolls and roll system to reduce the thermal deformation during rolling. Determine the crown parameter value through multiple iterative optimizations;

[0041] Step 2: Implementation of roller and roller system grinding technology: According to the optimized crown parameter value, prepare the corresponding grinding tools and equipment, use high-precision grinding equipment to accurately grind the roller and roller system to ensure that the crown meets the design requirements, and conduct quality inspection on the ground roller and roller system, including crown measurement, surface roughness detection, etc., to ensure that they meet the process requirements;

[0042] Step 3: Set up a cooling system for the rolls and roll system to cool them down, lower their temperature and reduce thermal deformation;

[0043] Step 4: Adjustment of rolling process parameters: According to the material and thickness of the aluminum strip, reasonably set the rolling speed to reduce the heat generated during the rolling process, and adjust the rolling pressure according to the crown design of the roller and the roller system to ensure that the aluminum strip is evenly stressed during the rolling process; preheat the aluminum strip to reduce the temperature difference between it and the roller;

[0044] Step 5: Design of rolling lubricant: Select lubricant with high strength and high heat dissipation performance to meet the lubrication requirements during the rolling process of aluminum strip, and ensure that the lubricant can evenly and fully cover the rollers and the aluminum strip to reduce friction and heat generation;

[0045] Step 6: Rolling: Connect the lubricating oil to the spray system, and arrange the nozzles above the rollers to ensure that the lubricating oil can evenly and fully cover the rollers and the aluminum strip to reduce friction and heat generation, and then roll the aluminum and aluminum alloys.

[0046] Wherein, the convexity parameter value of the cold rolling work roll determined in step one is 0.05 mm.

[0047] Wherein, the roughness of the working roll system after grinding in the step 2 is 0.45 μm, and the roughness of the backup roll system is 1 μm.

[0048] Among them, the cold rolling working rolls and support rolls are selected from materials with high thermal stability and low thermal expansion coefficient as the base materials of the rolling rolls and the roll system, such as tungsten steel, to further improve the thermal deformation resistance of the rolling rolls and the roll system.

[0049] The cooling system is a water cooling system inside the roller or an external air cooling system, which can effectively reduce the temperature of the roller and roller system and reduce thermal deformation by precisely controlling the flow and temperature of the cooling water or the wind speed and direction of the fan.

[0050] Among them, the rolling speed in the step four is like 1235 type aluminum material, with an average thickness of 3.12mm. In the biting stage, a lower rolling speed, such as 1m / s, is adopted to facilitate biting and avoid rolling cracking. In the intermediate rolling stage, a higher rolling speed is adopted to improve production efficiency. For example, when the thickness of the aluminum plate and strip is reduced to 2mm, the rolling speed can be increased to 5m / s. In the final rolling stage, due to the long contact time between the plate and the roller and the large temperature drop loss, in order to obtain uniform structure and performance, excellent surface quality and good plate shape, the rolling speed will be appropriately reduced and maintained at 2m / s.

[0051] Among them, the lubricating oil in step five is based on synthetic oil or mineral oil, and aromatic hydrocarbons are added as thickeners and components to enhance the strength of the oil film. In order to increase the viscosity and lubricating properties of the lubricating oil, hydrocarbon compounds with longer carbon chains can be added. These compounds help to form a stable oil film and reduce the friction between the aluminum plate and the roller. Antioxidants, rust inhibitors, and extreme pressure anti-wear agents can be added in appropriate amounts as needed to improve the performance of the lubricating oil and extend its service life.

[0052] The usage ratio of the base oil, aromatic hydrocarbons, hydrocarbon compounds with a longer carbon chain, antioxidants, rust inhibitors and extreme pressure and anti-wear agents is 9:0.3:0.3:0.05:0.1:0.1.

[0053] The working principle of the present invention is as follows: by optimizing the grinding of the rollers and roller systems of the cold rolling mill for aluminum and aluminum alloys, optimizing the parameter values ​​of the rollers and roller system convexity of the thermal deformation of the roller deformation zone during rolling, reducing the thermal deformation of the rollers and roller system during the rolling process of the aluminum plate and strip, being able to effectively control the accumulation of heat during the thermal deformation of the aluminum plate and strip, and preventing the production of embossing marks. The lubricating oil is designed to have high strength and to meet the requirements of uniform heat dissipation in the deformation zone of the aluminum plate, thereby improving the lubrication effect, preventing heat from gathering in the deformation zone of the aluminum plate, and reducing the probability of embossing marks on the plate surface.

[0054] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

[0055] The above embodiments are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for removing embossing marks on the surface of a cold-rolled strip, characterized in that: The specific steps include: Step 1: Design and optimization of the crown of the rolls and roll system: Use finite element analysis to simulate and analyze the crown of the rolls and roll system and the roll system of the support rolls at the cold rolling mill to predict their thermal deformation during the rolling process. According to the simulation results, adjust the crown design of the rolls and roll system to reduce the thermal deformation during rolling. Determine the crown parameter value through multiple iterative optimizations; Step 2: Implementation of roller and roller system grinding technology: According to the optimized crown parameter value, prepare the corresponding grinding tools and equipment, use high-precision grinding equipment to accurately grind the roller and roller system to ensure that the crown meets the design requirements, and conduct quality inspection on the ground roller and roller system, including crown measurement, surface roughness detection, etc., to ensure that they meet the process requirements; Step 3: Set up a cooling system for the rolls and roll system to cool them down, lower their temperature and reduce thermal deformation; Step 4: Adjustment of rolling process parameters: According to the material and thickness of the aluminum strip, reasonably set the rolling speed to reduce the heat generated during the rolling process, and adjust the rolling pressure according to the crown design of the roller and the roller system to ensure that the aluminum strip is evenly stressed during the rolling process; Step 5: Design of rolling lubricant: Select lubricant with high strength and high heat dissipation performance to meet the lubrication requirements during the rolling process of aluminum strip, and ensure that the lubricant can evenly and fully cover the rollers and the aluminum strip to reduce friction and heat generation; Step 6: Rolling: Connect the lubricating oil to the spray system, and arrange the nozzles above the rollers to ensure that the lubricating oil can evenly and fully cover the rollers and the aluminum strip to reduce friction and heat generation, and then roll the aluminum and aluminum alloys.

2. A method for removing embossing marks on the surface of a cold-rolled strip according to claim 1, characterized in that: The cold rolling work roll crown parameter value determined in step 1 is 0.03-0.05 mm.

3. A method for removing embossing marks on the surface of a cold-rolled strip according to claim 1, characterized in that: The roughness of the working roll system after grinding in the step 2 is between 0.35-0.45 μm, and the roughness of the backup roll system is between 0.8-1.0 μm.

4. A method for removing embossing marks on the surface of a cold-rolled strip according to claim 1, characterized in that: The cold rolling working rolls and support rolls are made of materials with high thermal stability and low thermal expansion coefficient as the base materials of the rolling rolls and the roll system, such as alloy forged steel with Cr, Ni, Si, infinitely chilled cast iron and tungsten steel, so as to further improve the thermal deformation resistance of the rolling rolls and the roll system.

5. The method for removing embossing marks on the surface of a cold-rolled strip according to claim 1, characterized in that: The cooling system is a water cooling system inside the roller or an external air cooling system, which effectively reduces the temperature of the roller and the roller system and reduces the thermal deformation by accurately controlling the flow and temperature of the cooling water or the wind speed and direction of the fan.

6. A method for removing embossing marks on the surface of a cold-rolled strip according to claim 1, characterized in that: The rolling speed in step 4 is like 1235 type aluminum material, with an average thickness of 3.12mm. In the biting stage, a lower rolling speed, such as between 0.5m / s-1m / s, is adopted to facilitate biting and avoid rolling cracking. In the intermediate rolling stage, a higher rolling speed is adopted to improve production efficiency. For example, when the thickness of the aluminum plate and strip is reduced to between 1mm-2mm, the rolling speed can be increased to 2m / s-5m / s. In the final rolling stage, due to the long contact time between the plate and the roller and the large temperature drop loss, in order to obtain uniform structure and performance, excellent surface quality and good plate shape, the rolling speed will be appropriately reduced and maintained between 1m / s-2m / s.

7. A method for removing embossing marks on the surface of a cold-rolled strip according to claim 1, characterized in that: In the step 5, the lubricating oil is based on synthetic oil or mineral oil, and aromatic hydrocarbons are added as thickeners and components to enhance the strength of the oil film. In order to increase the viscosity and lubricating properties of the lubricating oil, hydrocarbon compounds with longer carbon chains can be added. These compounds help to form a stable oil film and reduce the friction between the aluminum plate and the roller. Antioxidants, rust inhibitors, and extreme pressure anti-wear agents can be added in appropriate amounts as needed to improve the performance of the lubricating oil and extend its service life.

8. A method for removing embossing marks on the surface of a cold-rolled strip according to claim 7, characterized in that: The usage ratio of the base oil, aromatic hydrocarbons, hydrocarbon compounds with a longer carbon chain, antioxidants, rust inhibitors and extreme pressure and anti-wear agents is 9:0.3:0.3:0.05:0.1:0.1.