An advanced copper strip continuous rolling process

Abstract

The present application relates to copper plate strip processing technical field, provide a kind of advanced copper plate strip continuous rolling process, including S1.selecting the copper ingot of copper content above 99.9%, after sawing and surface polishing to obtain raw material;S2.copper ingot is heated in heating furnace, ensure the uniformity of copper ingot internal temperature;S3.using roughing mill to the copper ingot after heating is rolled through 2-3 passes roughing;S4.copper plate strip after roughing enters medium rolling mill, and medium rolling pass is 3-5 times;S5.copper plate strip after medium rolling enters finishing mill, and finishing pass is 3-4 times;S6.on-line cooling: copper plate strip after finishing immediately enters on-line cooling system.By early accurate sawing and polishing treatment, the initial quality of copper plate strip is guaranteed, the smooth progress of subsequent rolling process is ensured, the multi-pass continuous rolling process of roughing, medium rolling and finishing is combined with on-line cooling, through strict parameter control, not only improve production efficiency, but also effectively reduce energy consumption, reduce production cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of copper plate strip processing, in particular to an advanced copper plate strip continuous rolling process. BACKGROUND

[0002] As an important basic material, copper plate strip is widely used in many fields such as electronics, electrical appliances, automobiles, and construction. With the rapid development of modern industry, the quality and performance requirements of copper plate strip are increasingly improved. For example, in the electronics industry, high-precision and high-performance copper plate strip is crucial to ensure the stability and reliability of electronic products.

[0003] In the traditional process, the selection of roll material is not reasonable, and the hardness and cylindricity of the roll cannot meet the requirements of high-precision rolling, resulting in difficulty in controlling the thickness precision of the copper plate strip during continuous rolling, low production efficiency, and the lubrication method in the rolling process is relatively backward, increasing the friction between the roll and the copper plate strip, not only affecting the rolling efficiency, but also leading to poor surface quality of the product. SUMMARY

[0004] In view of the shortcomings of the prior art, the present application provides an advanced copper plate strip continuous rolling process, which solves the problem of difficulty in controlling the pressing precision of the copper plate strip in the prior art.

[0005] To achieve the above purpose, the present application realizes the following technical scheme: an advanced copper plate strip continuous rolling process, comprising the following steps:

[0006] S1. Plate strip blank preparation: select copper ingots with copper content of more than 99.9%, saw cut to make the size of the copper ingot meet the subsequent processing requirements, and control the sawing accuracy within ±0.5mm, then polish the surface of the copper ingot, and the polishing roughness reaches Ra0.8-Ra1.6μm;

[0007] S2. Heating treatment: heat the treated copper ingot in a heating furnace, the heating temperature range is 650-750℃, the heating rate is 30-50℃ / h, and the internal temperature uniformity of the copper ingot is ensured;

[0008] S3. Rough rolling process: use a rough rolling mill to roll the heated copper ingot, the roll diameter of the rough rolling mill is 800-1000mm, the rough rolling reduction is 20%-30%, the rolling speed is 30-50m / min, and after 2-3 passes of rough rolling, the thickness of the copper plate strip is reduced to 70%-80% of the original thickness;

[0009] S4. Intermediate rolling process: the rough-rolled copper plate strip enters the intermediate rolling mill, the surface hardness of the intermediate rolling mill roller is HRC58-HRC62, the intermediate rolling reduction is 15%-25%, the rolling speed is increased to 50-70 m / min, the intermediate rolling pass is 3-5 times, and the copper plate strip structure is further refined;

[0010] S5. Finishing rolling process: the intermediate-rolled copper plate strip enters the finishing rolling mill, the cylindrical error of the finishing rolling mill roller is less than 0.002 mm, the finishing rolling reduction is 10%-20%, the rolling speed is 70-100 m / min, the finishing rolling pass is 3-4 times, and the copper plate strip with target thickness and precision is obtained, and the target thickness tolerance is controlled within ±0.02 mm;

[0011] S6. Online cooling: the finishing-rolled copper plate strip immediately enters the online cooling system, the cooling medium is emulsion, the emulsion concentration is 3%-5%, the temperature is controlled at 20-30°C, the cooling speed is 50-100°C / s, and the copper plate strip temperature is reduced to 50-80°C.

[0012] Preferably, the sawed copper ingot in S1 is subjected to flaw detection, ultrasonic flaw detection method is adopted, the flaw detection frequency is 2-5 MHz, the detection sensitivity is φ2 mm flat bottom hole, and it is ensured that there is no obvious defect in the copper ingot.

[0013] Preferably, the atmosphere in the heating furnace in S2 is a mixed gas of inert gas and hydrogen, wherein the proportion of inert gas is 90%-95%, and the proportion of hydrogen is 5%-10%.

[0014] Preferably, the roller of the rough rolling mill in S3 is made of high nickel-chromium-molybdenum infinite hard cast iron material, the nickel content is 3%-5%, the chromium content is 1.5%-2.5%, and the molybdenum content is 0.2%-0.5%.

[0015] Preferably, the entrance and exit of the intermediate rolling mill are respectively provided with tension rollers, the entrance tension is 5-8 kN, and the exit tension is 8-12 kN.

[0016] Preferably, the roller lubrication of the finishing rolling mill adopts nanoscale graphite lubricant, the graphite particle size is 50-100 nm, and the supply amount of the lubricant is 5-10 ml / min.

[0017] Preferably, the spraying mode of the emulsion in S6 is air mist spraying, the distance between the nozzle and the copper plate strip is 20-30 cm, and the spraying angle is 30°-60°.

[0018] Preferably, the surface treatment of the cooled copper plate strip is pickling and passivation, the pickling adopts nitric acid solution with a concentration of 8%-12%, the pickling time is 3-5 minutes, the passivation adopts chromate passivation solution, the passivation time is 2-3 minutes, and a protective film is formed on the surface of the copper plate strip.

[0019] The application provides an advanced copper plate strip continuous rolling process.

[0020] 1、The application controls the sawing precision, surface polishing roughness and heating temperature uniformity to ensure the initial quality of the copper plate strip, ensures the smooth progress of the subsequent rolling process, and the multi-pass continuous rolling process of rough rolling, intermediate rolling and finish rolling is combined with online cooling, so that the production efficiency is improved, the energy consumption is effectively reduced, and the production cost is reduced.

[0021] 2、The application innovatively uses a mixed atmosphere of inert gas and hydrogen in the heating treatment link, effectively prevents the oxidation of the copper ingot at high temperature, ensures the purity of the material, and the selection of the roll material and lubrication mode of the rough rolling mill and the finish rolling mill further improves the rolling efficiency and product quality. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0023] Embodiment one:

[0024] The embodiment of the application provides an advanced copper plate strip continuous rolling process, which comprises the following steps:

[0025] S1. Select a copper ingot with a copper content of 99.95%, use a high-precision sawing machine to saw, and control the sawing precision to be ±0.5mm. The size of the sawed copper ingot meets the feeding requirements of the subsequent rough rolling mill. Then, use a polishing device to polish the surface of the copper ingot, and the roughness after polishing reaches Ra1.2μm. Then, use an ultrasonic flaw detector to detect the sawed copper ingot, set the detection frequency to 3MHz, and the detection sensitivity to φ2mm flat bottom hole. The detected copper ingot has no obvious internal defects. The high-quality copper ingot and accurate size control reduce the stress concentration phenomenon in the rolling process and reduce the possibility of cracks and other defects in the copper plate strip. Accurate flaw detection can avoid copper ingots with internal problems from entering subsequent processing, thereby reducing the scrap rate, improving production efficiency and economic benefits;

[0026] S2. The processed copper ingot is placed in a heating furnace, which is filled with a mixture of 92% inert gas and 8% hydrogen. The copper ingot is heated from room temperature to 700°C at a rate of 40°C / hour. During this process, the internal temperature uniformity of the copper ingot is ensured by a temperature sensor and control system, with temperature fluctuations within the allowed range. Suitable heating atmosphere and rate, as well as precise temperature control, help maintain the good performance of the copper ingot, prevent oxidation and internal organizational defects, reduce surface defects caused by oxidation scale and mechanical property fluctuations caused by internal organizational unevenness, and improve product consistency and quality stability.

[0027] S3. The heated copper ingot is rolled using a rough rolling mill with a roll diameter of 900mm. The roll of the rough rolling mill is made of high nickel-chromium-molybdenum unlimited hard cast iron, with a nickel content of 4%, a chromium content of 2%, and a molybdenum content of 0.3%. The rough rolling reduction is 25%, and the rolling speed is 40m / min. After 3 passes of rough rolling, the thickness of the copper plate strip is reduced to 75% of the original thickness. The multi-pass and appropriate reduction rolling method can make the copper material deform uniformly during rolling, avoiding material rupture or internal stress concentration caused by excessive single reduction.

[0028] S4. The rough-rolled copper plate strip enters the intermediate rolling mill, and the surface hardness of the intermediate rolling mill roll is HRC60. Tension rolls are set at the inlet and outlet of the intermediate rolling mill, with an inlet tension of 6kN and an outlet tension of 10kN. The intermediate rolling reduction is 20%, and the rolling speed is increased to 60m / min. The intermediate rolling passes are 4 times, which further refines the copper plate strip organization. Suitable roll hardness and reasonable tension setting can ensure the stability of the intermediate rolling process and product quality, reduce the shape defects of the copper plate strip in the rolling process, such as wavy or side bending, and optimize the reduction, rolling speed and pass to further refine the copper plate strip organization, improve its flatness and dimensional accuracy, and make the copper plate strip closer to the requirements of the final product.

[0029] S5. The intermediate-rolled copper plate strip enters the finishing rolling mill, and the cylindrical error of the finishing rolling mill roll is 0.0015mm. The roll lubrication of the finishing rolling mill uses nanoscale graphite lubricant, with a graphite particle size of 80nm and a lubricant supply amount of 8ml / min. The finishing rolling reduction is 15%, the rolling speed is 80m / min, and the finishing rolling passes are 3 times to obtain the target thickness and precision of the copper plate strip, with a target thickness tolerance controlled within ±0.02mm. The use of high-precision roll cylindrical and nanoscale graphite lubricant can significantly improve the quality of the finished product, uniform pressure distribution reduces thickness deviation, good lubrication effect reduces the friction between the roll and the copper plate strip, reduces the possibility of roll wear and copper plate strip surface scratches, improves the surface finish and dimensional accuracy of the copper plate strip, and makes it suitable for applications with high precision requirements.

[0030] S6. The copper strip after finish rolling immediately enters an online cooling system, the cooling medium is emulsion, the emulsion concentration is 4%, and the temperature is controlled at 25 DEG C. The emulsion is sprayed in the form of gas mist, the distance between the nozzle and the copper strip is 25 cm, the spraying angle is 45 DEG, the cooling speed is 80 DEG C / s, the temperature of the copper strip is reduced to 65 DEG C, and uniform cooling can avoid deformation of the copper strip due to local temperature difference, improve the flatness and dimensional stability of the product, and ensure that the product quality meets the requirements.

[0031] Example two:

[0032] The embodiment of the application provides a kind of advanced copper strip continuous rolling process, comprising the following steps:

[0033] S1. Selecting copper ingot with copper content of 99.98%, it is processed by sawing, and sawing accuracy is strictly controlled within ±0.5mm, then the surface of copper ingot is carefully polished to roughness of Ra0.8 μm. Ultrasonic flaw detection is carried out on the sawed copper ingot, the flaw detection frequency is set to 5MHz, the detection sensitivity is φ2mm flat bottom hole, and after confirming that there is no defect in the copper ingot, the next step is prepared.

[0034] S2. The copper ingot is placed in a heating furnace, and the atmosphere in the heating furnace is a mixed gas composed of 95% inert gas and 5% hydrogen. The copper ingot is heated to 650 DEG C at a heating rate of 30 DEG C / hour, to ensure uniform internal temperature of the copper ingot, and the temperature deviation is within the allowable range.

[0035] S3. The heated copper ingot is rolled using a rough rolling mill with a roll diameter of 800 mm, the rough rolling mill roll is high nickel-chromium-molybdenum unlimited cold hardening cast iron material, the nickel content is 3%, the chromium content is 1.5%, and the molybdenum content is 0.2%, the rough rolling reduction is 20%, and the rolling speed is 30 m / min, after 2 passes of rough rolling, the copper strip thickness is reduced to 70% of the original thickness.

[0036] S4. The copper strip after rough rolling enters the intermediate rolling mill, and the surface hardness of the intermediate rolling mill roll is HRC58. Tension rolls are arranged at the inlet and outlet of the intermediate rolling mill, the inlet tension is 5 kN, and the outlet tension is 8 kN. The intermediate rolling reduction is 15%, the rolling speed is 50 m / min, the intermediate rolling pass is 3 times, and the copper strip organization is refined.

[0037] S5. The copper strip after intermediate rolling enters the finish rolling mill, and the cylindrical error of the finish rolling mill roll is less than 0.002 mm. The finish rolling mill roll lubrication uses nanoscale graphite lubricant, the graphite particle size is 50 nm, and the lubricant supply amount is 5 ml / min. The finish rolling reduction is 10%, the rolling speed is 70 m / min, the finish rolling pass is 3 times, so that the copper strip reaches the target thickness and precision, and the thickness tolerance is within ±0.02 mm.

[0038] S6. The copper plate strip after finish rolling enters an online cooling system, and the cooling medium is emulsion with a concentration of 3% and a temperature of 20 DEG C. The emulsion is sprayed by air spray, the nozzle is 20 cm away from the copper plate strip, the spray angle is 30 DEG, the cooling speed is 50 DEG / s, and the temperature of the copper plate strip is reduced to 50 DEG C.

[0039] S7. The copper plate strip after cooling is subjected to surface treatment, pickling is performed by using nitric acid solution with a concentration of 8%, the pickling time is 3 minutes, passivation is performed by using chromate passivation solution, the passivation time is 2 minutes, a protective film is formed on the surface of the copper plate strip, and pickling and passivation treatment can significantly improve the surface quality and corrosion resistance of the copper plate strip. The copper plate strip after removal of surface impurities is more in line with the requirements of high-quality products in appearance and performance, and the formation of the passivation film can prolong the service life of the copper plate strip, so that the copper plate strip can maintain good performance under different environmental conditions, and the application range of the copper plate strip is widened.

[0040] In summary, the continuous rolling process of the embodiment of the application is closely matched at each link, the production efficiency, product quality and performance of the copper plate strip are effectively improved through accurate parameter control and advanced process means, and high-precision and high-quality continuous rolling production of the copper plate strip can be realized.

[0041] Although the embodiments of the application have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirits of the application, the scope of the application is defined by the appended claims and their equivalents.

Claims

1. An advanced continuous rolling process for copper strip, characterized in that, Includes the following steps: S1. Preparation of sheet and strip billet: Select copper ingots with a copper content of 99.9% or higher, and cut them to make the dimensions of the copper ingots meet the requirements of subsequent processing. The sawing accuracy is controlled within ±0.5mm. Then, the copper ingots are surface-polished to achieve a roughness of Ra0.8-Ra1.6μm. S2. Heat treatment: The polished copper ingot is heated in a heating furnace at a temperature range of 650℃-750℃ and a heating rate of 30-50℃ / hour to ensure uniform temperature inside the copper ingot. S3. Rough rolling process: The heated copper ingot is rolled using a rough rolling mill. The diameter of the rolls of the rough rolling mill is 800-1000mm, the rough rolling reduction rate is 20%-30%, and the rolling speed is 30-50m / min. After 2-3 passes of rough rolling, the thickness of the copper strip is reduced to 70%-80% of the original thickness. S4. Intermediate rolling process: The copper strip after rough rolling enters the intermediate rolling mill. The surface hardness of the intermediate rolling mill rolls is HRC58-HRC62, the intermediate rolling reduction rate is 15%-25%, the rolling speed is increased to 50-70m / min, and the intermediate rolling passes are 3-5 times to further refine the copper strip structure. S5. Finishing Rolling Process: The copper strip after intermediate rolling enters the finishing mill. The cylindricity error of the finishing mill rolls is less than 0.002mm. The finishing rolling reduction rate is 10%-20%, the rolling speed is 70-100m / min, and the finishing rolling passes are 3-4 times to obtain copper strip with the target thickness and accuracy. The target thickness tolerance is controlled within ±0.02mm. S6. Online cooling: The finished copper strip immediately enters the online cooling system. The cooling medium is an emulsion with a concentration of 3%-5%. The temperature is controlled at 20℃-30℃, and the cooling rate is 50-100℃ / second, reducing the temperature of the copper strip to 50℃-80℃.

2. The advanced continuous rolling process for copper strip according to claim 1, characterized in that, The copper ingots cut in S1 are subjected to flaw detection using ultrasonic testing. The testing frequency is 2-5MHz, and the detection sensitivity is φ2mm flat-bottomed hole, to ensure that there are no obvious defects inside the copper ingots.

3. The advanced continuous rolling process for copper strip according to claim 1, characterized in that, The atmosphere inside the heating furnace in S2 is a mixture of inert gas and hydrogen, with inert gas accounting for 90%-95% and hydrogen accounting for 5%-10%.

4. The advanced continuous rolling process for copper strip according to claim 1, characterized in that, The rolls of the roughing mill in S3 are made of high-nickel-chromium-molybdenum indefinite chilled cast iron, with a nickel content of 3%-5%, a chromium content of 1.5%-2.5%, and a molybdenum content of 0.2%-0.5%.

5. The advanced continuous rolling process for copper strip according to claim 1, characterized in that, Tension rollers are installed at the inlet and outlet of the intermediate rolling mill, with an inlet tension of 5-8 kN and an outlet tension of 8-12 kN.

6. The advanced continuous rolling process for copper strip according to claim 1, characterized in that, The rolling mill rolls are lubricated with nano-grade graphite lubricant, with graphite particles having a diameter of 50-100 nm and a lubricant supply rate of 5-10 ml / min.

7. The advanced continuous rolling process for copper strip according to claim 1, characterized in that, The emulsion in S6 is sprayed as an aerosol, with the nozzle 20-30cm away from the copper strip and the spray angle 30°-60°.

8. The advanced continuous rolling process for copper strip according to claim 1, characterized in that, It also includes surface treatment of the copper strip after online cooling. The surface treatment is pickling and passivation. Pickling uses a nitric acid solution with a concentration of 8%-12% and a pickling time of 3-5 minutes. Passivation uses a chromate passivation solution and a passivation time of 2-3 minutes to form a protective film on the surface of the copper strip.