Method for strengthening surface of cathode roller

Abstract

The invention relates to a method for strengthening the surface of a cathode roller, which is characterized in that turning, grinding, shot blasting and polishing are taken as the basis, a new machining method is formed by combining new working procedures, the coaxiality of the surface of a titanium cylinder of the machined cathode roller is less than or equal to 0.05 mm, the circle run-out degree is less than or equal to 0.05 mm, the straightness is less than or equal to 0.05 mm, and the surface roughness is less than Ra 0.3; the mirror surface effect is achieved, and surface defects such as cross grains, cross grains, chromatic aberration and bright spots are avoided; the stress corrosion resistance of the cathode roller titanium cylinder is improved, the time of surface defects in the electrolytic copper foil production process is greatly delayed, the service life of the cathode roller is prolonged, the production efficiency of the cathode roller is improved, the effect superior to that of an existing machining method is achieved, the corrosion resistance of the cathode roller is remarkably improved, and the service cycle of the cathode roller is greatly prolonged. And the product meets the use requirements of high-end copper foils with high tensile strength and high elongation. According to the method, the required equipment is high in maturity, the equipment purchase cost and the processing cost are not obviously increased, and the method has good operability and economical efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of electrolytic copper foil production equipment, and in particular to a processing method for strengthening the surface of a cathode roller titanium cylinder in the electrolytic copper foil manufacturing industry. Background Art

[0002] The manufacturing principle of electrolytic copper foil is electrochemical reaction. The process is to continuously deposit copper ions in the copper sulfate solution from the anode tank as the anode to the surface of the cathode roller as the cathode under the action of electric current. When a certain thickness is reached, it is peeled, surface treated and rolled up to finally produce electrolytic copper foil continuously. As an important component of the negative electrode material of lithium batteries, electrolytic copper foil has benefited from the high-quality development trend of the lithium battery industry chain and has continued to develop in the direction of high precision, ultra-thinness and high safety. High-end copper foils with high tensile strength and high elongation have been developed one after another, such as copper foil for high-frequency (speed) circuits, high-frequency flexible copper foil, and ultra-thin copper foil for high-precision energy storage. In order to meet the product quality requirements of electrolytic copper foil, large-size, high-performance cathode rollers have always been the focus and development direction of copper foil manufacturers. As the core component of the cathode roller, the surface quality of the titanium cylinder is the main factor determining the quality of the electrolytic copper foil. If the surface roughness of the titanium cylinder is low and the grains are fine and uniform, it is easy to generate electrolytic copper foil with fine grains, high tensile strength and high elongation. On the contrary, the electrolytic copper foil generated will have coarse grains, be thicker and have poor toughness. Therefore, it is particularly important to choose a suitable processing method.

[0003] In the prior art, the conventional processing methods used for the outer surface of the titanium cylinder after thermal assembly are turning and polishing. This method has the characteristics of long processing time, poor precision, and easy surface defects after use. At present, the processing methods commonly used by domestic cathode roller manufacturers for the outer surface of the titanium cylinder after thermal assembly are turning, grinding, ultrasonic rolling and polishing. This method produces plastic rheological structure on the outer surface of the titanium cylinder by adding an ultrasonic rolling process, and the grain structure is more compact, which effectively reduces the stress corrosion of the cathode roller. However, the plastic rheological structure layer produced by ultrasonic rolling is relatively thin. After a period of use, especially in the production process of lithium battery copper foil, surface defects will still appear on the surface of the titanium cylinder. According to statistics, the time for surface defects to appear on the titanium cylinder processed by ultrasonic rolling process is only 3 to 6 months longer than that of the titanium cylinder without ultrasonic rolling process, which has little effect on extending the service life of the cathode roller.

[0004] A method for processing the outer surface of a TA1 cathode roller is disclosed in the publication number CN 109333012 A, which includes four processes: turning, grinding, ultrasonic rolling and polishing. When turning, the surface defects such as oxidized black skin, spinning lines, peeling and cracks on the outer surface of the cathode roller are removed. When grinding, the outer surface of the cathode roller is continuously polished and knocked with a thousand-leaf wheel to reduce the surface roughness value, eliminate part of the processing residual stress, and reduce stress corrosion. When ultrasonic rolling, a plastic rheological structure is formed on the outer surface of the cathode roller to further reduce stress corrosion. When polishing, the surface roughness value is further reduced, so that the outer surface of the cathode roller is delicate, without color difference, any black spots, straight lines and diagonal lines and other surface defects. This patent mainly improves the surface structure of the cathode roller by adding an ultrasonic rolling process, eliminates part of the residual stress, and achieves the purpose of reducing stress corrosion and extending the service life. However, due to the thin thickness of the ultrasonic rolling action layer and the limited range of action, it has little effect on improving the surface structure and has not significantly extended the service life. Summary of the invention

[0005] In order to overcome the shortcomings of the cathode roller titanium cylinder in the prior art in the production of electrolytic copper foil, such as surface defects and short service life, the present invention provides a method for strengthening the cathode roller surface.

[0006] The specific process of the present invention is:

[0007] Step 1, turning:

[0008] The turning process of the outer surface of the cathode roller blank includes rough turning and fine turning.

[0009] Ⅰ Rough turning:

[0010] During rough turning, the cathode roller blank has a rotation speed of 8-10 r / min, a feed rate of 0.4-0.5 mm / r, and a turning depth of 2 mm. A cathode roller blank after rough turning is obtained.

[0011] After rough turning, measure the cathode roller diameter, which should be 2mm larger than the final size, leaving a 1mm margin for fine turning. The surface roughness should be less than Ra3.2.

[0012] Ⅱ Fine turning:

[0013] The circumferential surface of the cathode roller blank is fine-turned to obtain a cathode roller blank with an outer circumferential surface turned.

[0014] The process parameters of the fine turning process are: the rotation speed of the cathode roller blank is 10-12r / min, the feed rate is 0.2-0.3mm / r, and the turning depth is 0.5mm.

[0015] After the fine turning, the outer diameter of the cathode roller blank obtained has a processing allowance of 1 mm, of which 0.5 mm is the allowance for shot blasting and grinding.

[0016] The surface roughness of the cathode roller is less than Ra1.6, the coaxiality is ≤0.05mm, the roundness is ≤0.05mm, and the straightness is ≤0.05mm.

[0017] Step 2, Grinding:

[0018] The grinding is to grind the outer surface of the cathode roller blank after turning, including rough grinding and fine grinding.

[0019] Ⅰ Rough grinding. Turn on the grinder and check the roundness of the copper sleeves at both ends to be ≤0.05mm. Use 40# PVA grinding wheel for rough grinding. Turn on the spray device switch and use a diamond pen to grind the roundness of the PVA grinding wheel surface. Face the knife at the end of the cathode roller and start rough grinding. Roughly grind 5 to 10 times until there are no tool marks, scratches, ripples, spots, or bright spots on the surface of the cathode roller, and the two sides must not collapse or warp. Obtain the rough-ground cathode roller blank.

[0020] The process parameters of the rough grinding process are as follows: the cathode roller speed is 3-4 r / min, the grinding wheel speed is 500 r / min, the grinding wheel feed is 20-25 mm / r, and the flexible grinding head cylinder pressure is 0.3 MPa.

[0021] Ⅱ Fine grinding.

[0022] Use 60# PVA grinding wheel to fine grind the cathode roller blank after rough grinding; use diamond pen to grind the surface roundness of PVA grinding wheel, face the knife at the end of cathode roller, and start fine grinding. Fine grinding is performed 5 to 10 times until the surface of cathode roller reaches Ra0.8 or less.

[0023] The process parameters of the fine grinding process are: the cathode roller speed is 3-4r / min, the grinding wheel speed is 600r / min, the grinding wheel feed is 15-20mm / r, and the flexible grinding head cylinder pressure is 0.2MPa.

[0024] Step 3, shot blasting:

[0025] The shot blasting is to perform shot blasting on the outer surface of the cathode roller blank that has completed the grinding process, including primary shot blasting and secondary shot blasting.

[0026] Ⅰ One-time shot blasting. Shield the two end faces of the cathode roller blank, and completely shield and protect the shaft, copper sleeve and titanium sleeve. Hoist the protected cathode roller to the shot blasting station, so that the bearing and the bearing seat are tightly matched.

[0027] Use ceramic shot as the projectile for a shot blasting process;

[0028] Turn on the shot blasting station switch, turn on the shot blasting system and ventilation and dust removal system, and start shot blasting. After one shot blasting is completed, use cotton yarn or compressed air to blow away the projectiles and dust remaining on the surface of the cathode roller. Use a magnifying glass of more than 10 times to check the surface coverage, and the surface coverage should reach 100%.

[0029] The process parameters of the shot blasting process are set as follows: cathode roller rotation speed is 0.5-1 r / min, nozzle moving speed is 2-3.7 mm / r, shot speed is 150 m / s, projectile angle is 90°, and projectile distance L=100 mm.

[0030] Ⅱ Secondary shot blasting.

[0031] After the first shot blasting is completed, glass shot is used as the projectile for the second shot blasting; turn on the shot blasting station switch, turn on the shot blasting system and ventilation and dust removal system, and start shot blasting. After the second shot blasting is completed, cotton yarn or compressed air is used to blow away the projectiles and dust remaining on the surface of the cathode roller blank. Use a magnifying glass of more than 10 times to check the surface coverage, and the surface coverage reaches 100%.

[0032] The process parameters of the secondary shot blasting are set as follows: the rotation speed of the cathode roller semi-finished blank is 1-1.2 r / min, the nozzle moving speed is 1.9-2.1 mm / r, the shot speed is 250 m / s, the projectile angle is 90°, and the projectile distance is 100 mm.

[0033] After the shot blasting is completed, a semi-finished product of the cathode roller is obtained.

[0034] The uniformity of the size of the ceramic shot is: when the standard screen allows a maximum of 0.5% of the weight to be retained, the number of meshes is 14 and the size of the mesh hole is 1.1 mm. When the standard screen allows a maximum of 20% of the weight to pass, the number of meshes is 20 and the size of the mesh hole is 0.85 mm. The uniformity of the shape of the ceramic shot is: the flat area of ​​the shot is 12.7×12.7 mm 2 ; The maximum number of projectiles with unqualified shapes allowed is 14.

[0035] The uniformity of the size of the glass pellets is: when the standard screen allows at most 0.5% of the weight to be retained, the number of meshes is 7 and the size of the mesh hole is 2.8mm. When the standard screen allows at most 20% of the weight to pass, the number of meshes is 12 and the size of the mesh hole is 1.7mm. The uniformity of the shape of the glass pellets is: the flat area of ​​the pellets is 25.4×25.4mm 2 ; The maximum number of projectiles with unqualified shapes allowed is 14.

[0036] Step 4, polishing:

[0037] The polishing is to polish the outer surface of the cathode roller semi-finished product after shot blasting, including rough polishing and fine polishing.

[0038] Ⅰ Rough polishing.

[0039] Use 120# PVA grinding wheel for rough polishing.

[0040] The process parameters of the rough polishing process are set as follows: the cathode roller semi-finished product rotation speed is 4-5r / min, the grinding wheel rotation speed is 700r / min, the grinding wheel feed rate is 10-12mm / r, and the flexible grinding head cylinder pressure is 0.2MPa.

[0041] Turn on the spray device switch and use a diamond pen to grind the roundness of the PVA grinding wheel surface. Face the semi-finished end of the cathode roller with a knife and start rough polishing. Rough polish 3 to 5 times until there is no shot blasting mark on the surface of the cathode roller.

[0042] Ⅱ Fine polishing.

[0043] A 220# PVA grinding wheel is selected to perform fine polishing on the roughly polished cathode roller blank.

[0044] The process parameters of the fine polishing process are set as follows: cathode roller speed is 4-5r / min, grinding wheel speed is 800r / min, grinding wheel feed is 5-6mm / r, and flexible grinding head cylinder pressure is 0.1MPa.

[0045] Use diamond pen to grind the roundness of PVA grinding wheel surface, face the knife at the end of cathode roller, and start fine polishing. Fine polish 3 to 5 times until there is no surface defect on the surface of cathode roller, and the surface roughness is less than Ra0.3.

[0046] At this point, the processing of the outer surface of the cathode roller with a diameter of 2700mm to 3600mm has been completed.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] The present invention turns the outer surface of the cathode roller titanium cylinder after hot assembly, and the turning depth is ≥2.5mm, and the spinning pattern, oxide scale, black skin, etc. on the outer surface of the cathode roller titanium cylinder are removed. During grinding, a coarse-mesh PVA wheel is used to continuously grind the surface of the cathode roller titanium cylinder, and rough grinding removes the turning marks, and fine grinding reduces the surface roughness. During shot blasting, high-speed projectiles strongly impact the surface of the cathode roller titanium cylinder, resulting in strong plastic deformation, forming a strengthening layer with a depth of 2 to 2.5mm, and the organization structure in the strengthening layer is fine, and a higher residual compressive stress is introduced at the recrystallization temperature, which significantly improves the stress corrosion resistance. During polishing, a fine-mesh PVA wheel is used to continuously polish the surface of the cathode roller titanium cylinder, and rough polishing removes the shot blasting marks, and fine polishing further reduces the surface roughness, so that the surface has no surface defects such as diagonal lines, no horizontal lines, color difference, bright spots, etc., and meets the use requirements. The present invention provides a cathode roller reinforced titanium cylinder processing process method, wherein the surface coaxiality of the processed cathode roller titanium cylinder is ≤0.05mm, the roundness is ≤0.05mm, the straightness is ≤0.05mm, and the surface roughness is below Ra0.3; a mirror effect is achieved, and there are no surface defects such as diagonal lines, horizontal lines, color difference, and bright spots; the stress corrosion resistance of the cathode roller titanium cylinder is improved, and the time for the occurrence of surface defects in the electrolytic copper foil production process is greatly delayed, thereby improving the use time and production efficiency of the cathode roller. The copper foil produced by the present invention meets the use requirements of high-end copper foil with high tensile strength and high elongation.

[0049] At present, the processing methods commonly used by domestic cathode roller manufacturers for the outer surface of the titanium cylinder after thermal assembly are turning, grinding, ultrasonic rolling and polishing. The processing method of the present invention is turning, grinding, shot blasting and polishing. The difference between the two processing methods is that ultrasonic rolling is replaced by shot blasting, and the other processes are the same. In the processing method of the present invention, each process is conventional technology, the required equipment is common equipment, the equipment maturity is high, and there is no obvious increase in equipment purchase cost and processing cost. Therefore, the processing method of the present invention is highly operable and economical.

[0050] Table 1 Equipment comparison list

[0051] Ultrasonic rolling equipment Shot blasting machine price 500,000 to 600,000 yuan / unit 100,000 to 300,000 yuan / unit

[0052] The shot blasting process has not been applied in the processing of cathode rollers. The existing technology is ultrasonic rolling, the principle of which is to form plastic deformation and surface compressive stress on the outer surface of the cathode roller through ultrasonic rolling. A certain plastic deformation forms a certain thickness of plastic rheological structure on the outer surface of the cathode roller. After measurement, the thickness is about 0.5mm. The plastic rheological structure has a high grain size, uniform structure, and good corrosion resistance. The surface compressive stress can eliminate the processing residual stress again, so as to achieve the purpose of reducing the stress corrosion of the cathode roller during electrolytic foil production.

[0053] The effect of shot blasting is similar to that of ultrasonic rolling. It forms a certain thickness of plastic rheological structure by high-speed impact of the projectile on the outer surface of the cathode roller. The thickness is about 2 to 2.5 mm after simulation, which is 4 to 5 times the thickness of ultrasonic rolling. Therefore, the plastic deformation and surface compressive stress generated by shot blasting are greater than those of ultrasonic rolling, making the grain structure denser.

[0054] In summary, the present invention is based on conventional processing technology and forms a new processing method through a new process combination, which produces an effect that is superior to the existing processing method, significantly improves the corrosion resistance of the cathode roller, and greatly extends the service life of the cathode roller. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 It is a flow chart of the present invention.

[0056] Figure 2 is a schematic diagram of the structure of the cathode roller; Figure 2 a is the main view, where Figure 2 b is a local enlarged view of site I in 2a.

[0057] Figure 3 It is the front view of the rubber sheet.

[0058] Figure 4 It is a simulation model of projectile impact.

[0059] Figure 5 It is a simulation of the projectile impact result.

[0060] In the figure: 1. shaft; 2. copper sleeve; 3. titanium sleeve; 4. bolt; 5. rubber plate; 6. titanium cylinder; 7. roller core; 8. projectile; 9. test block; 10. action area of ​​the projectile on the test block. DETAILED DESCRIPTION

[0061] The invention is a method for processing the outer surface of a cathode roller with a diameter of 2700 mm to 3600 mm, and is mainly used for cathode rollers of three common diameters of 2700 mm, 3000 mm and 3600 mm.

[0062] The present invention will describe its technical solution in detail through three embodiments. The specific process is:

[0063] Step 1, Turning:

[0064] The outer surface of the cathode roller blank assembled from the titanium cylinder blank 6 and the roller core 7 blank is turned; the turning process includes rough turning and fine turning.

[0065] Ⅰ Rough turning: Turn on the CNC horizontal lathe, hoist the cathode roller blank on the lathe; clamp the steel shaft at one end with the chuck, clamp the steel shaft at the other end with the tailstock, align the two ends of the steel shaft, and make the roundness of the two ends of the steel shaft ≤0.03mm. Use YG8 carbide blades for rough turning.

[0066] The process parameters of rough turning are: cathode roller speed of 8-10r / min, feed rate of 0.4-0.5mm / r, and turning depth of 2mm.

[0067] After rough turning, measure the cathode roller diameter, which should be 2mm larger than the final size, leaving a 1mm margin for fine turning. Measure the surface roughness, which should be below Ra3.2.

[0068] Ⅱ Fine turning:

[0069] After the rough turning is completed, the YG8 carbide blade is replaced and the circumferential surface of the cathode roller is fine-turned to obtain a cathode roller whose outer circumferential surface has been turned.

[0070] The process parameters of the fine turning process are: the cathode roller rotation speed is 10-12 r / min, the feed rate is 0.2-0.3 mm / r, and the turning depth is 0.5 mm.

[0071] The outer diameter of the cathode roller obtained after fine turning has a processing allowance of 1 mm.

[0072] 1mm larger than the final size, of which 0.5mm is for shot blasting and grinding allowance.

[0073] The surface roughness of the cathode roller is less than Ra1.6, the coaxiality is ≤0.05mm, the roundness is ≤0.05mm, and the straightness is ≤0.05mm.

[0074] Table 2 Process parameters of each embodiment in step 1

[0075]

[0076] Step 2, Grinding:

[0077] The grinding is to grind the outer surface of the cathode roller after turning, including rough grinding and fine grinding.

[0078] After the turning process is completed, the cathode roller is removed from the lathe, bearings are installed on the copper sleeves 2 at both ends, and the cathode roller is hoisted on the grinder so that the bearings and the bearing seats are tightly matched.

[0079] Ⅰ Rough grinding. Turn on the grinder and check the roundness of the copper sleeves 2 at both ends to be ≤0.05mm. Use 40# PVA grinding wheel for rough grinding. Turn on the spray device switch and use a diamond pen to grind the roundness of the PVA grinding wheel surface. Face the knife at the end of the cathode roller and start rough grinding. Roughly grind 5 to 10 times until there are no tool marks, scratches, ripples, spots, or bright spots on the surface of the cathode roller, and the two sides must not collapse or warp. Get a rough-ground cathode roller.

[0080] The grinding process is to move the PVA grinding wheel to the vicinity of the diamond pen, face the knife at the end of the PVA grinding wheel, and start grinding. The outer cylindrical surface of the PVA grinding wheel is required to be completely ground. The grinding process parameters are set as follows: the grinding wheel speed is 500r / min, and the grinding wheel feed is 5mm / r. The diamond pen is located at one end of the grinding machine track.

[0081] The process parameters of the rough grinding process are as follows: the cathode roller speed is 3-4 r / min, the grinding wheel speed is 500 r / min, the grinding wheel feed is 20-25 mm / r, and the flexible grinding head cylinder pressure is 0.3 MPa.

[0082] Ⅱ Fine grinding.

[0083] After the rough grinding is completed, select 60# PVA grinding wheel for fine grinding. Use diamond pen to grind the roundness of the PVA grinding wheel surface, and start fine grinding at the end of the cathode roller. Fine grinding 5 to 10 times until the surface of the cathode roller reaches Ra0.8 or less.

[0084] The grinding process is to move the PVA grinding wheel to the vicinity of the diamond pen, face the knife at the end of the PVA grinding wheel, and start grinding. The outer cylindrical surface of the PVA grinding wheel is required to be completely ground. The grinding process parameters are set as follows: the grinding wheel speed is 500r / min, and the grinding wheel feed is 5mm / r. The diamond pen is located at one end of the grinding machine track.

[0085] The process parameters of the fine grinding process are: the cathode roller speed is 3-4r / min, the grinding wheel speed is 600r / min, the grinding wheel feed is 15-20mm / r, and the flexible grinding head cylinder pressure is 0.2MPa.

[0086] Table 3 Process parameters of each embodiment in step 2

[0087]

[0088] Step 3, shot blasting:

[0089] The shot blasting is to perform shot blasting on the outer surface of the cathode roller after grinding, including primary shot blasting and secondary shot blasting.

[0090] Ⅰ. One-time shot blasting. After the grinding process is completed, the cathode roller is removed from the grinder and transported to the shot blasting room. The two end faces of the cathode roller are shielded with rubber sheets, and the shaft 1, copper sleeve 2 and titanium sleeve 3 are completely shielded and protected with plastic film. The protected cathode roller is hoisted to the shot blasting station so that the bearing and the bearing seat are tightly matched.

[0091] Ceramic shot AZB850 is selected as the projectile for a shot blasting process; the process parameters of the shot blasting process are set as follows: the cathode roller speed is 0.5-1r / min, the nozzle moving speed is 2-3.7mm / r, the projectile speed is 150m / s, the projectile angle is 90°, and the projectile distance L=100mm.

[0092] Turn on the shot blasting station switch, turn on the shot blasting system and ventilation and dust removal system, and start shot blasting. After one shot blasting is completed, use cotton yarn or compressed air to blow away the projectiles and dust remaining on the surface of the cathode roller. Use a magnifying glass of more than 10 times to check the surface coverage, and the surface coverage should reach 100%.

[0093] Ⅱ Secondary shot blasting.

[0094] After the first shot blasting process is completed, glass shot AGB200 is selected as the projectile for the second shot blasting process; the process parameters of the second shot blasting process are set as follows: cathode roller speed is 1-1.2r / min, nozzle moving speed is 1.9-2.1mm / r, projectile speed is 250m / s, projectile angle is 90°, and projectile distance is 100mm.

[0095] Turn on the shot blasting station switch, turn on the shot blasting system and ventilation and dust removal system, and start shot blasting. After the second shot blasting is completed, use cotton yarn or compressed air to blow away the remaining projectiles and dust on the surface of the cathode roller. Use a magnifying glass of more than 10 times to check the surface coverage, and the surface coverage should reach 100%.

[0096] Table 4 Process parameters of each embodiment in step 3

[0097]

[0098] After the shot blasting is completed, the plastic film and rubber sheet used for shielding protection are removed, and the offset print left by the tape or adhesive tape is removed.

[0099] The rubber sheet is made of PVC, with a thickness of 10 mm, an outer diameter consistent with the diameter of the cathode roller, and an inner diameter of 500 mm. A circle of threaded holes is processed near the outer edge, the number of which is consistent with the threaded holes on the end face of the cathode roller, and the rubber sheet is fixed to the side of the cathode roller by bolts.

[0100] The ceramic pellets used in the first shot blasting are AZB850 ceramic pellets. The glass pellets used in the second shot blasting are AGB200 glass pellets.

[0101] The uniformity of the size of the ceramic shot is: when the standard screen allows a maximum of 0.5% of the weight to be retained, the number of meshes is 14 and the size of the mesh hole is 1.1 mm. When the standard screen allows a maximum of 20% of the weight to pass, the number of meshes is 20 and the size of the mesh hole is 0.85 mm. The uniformity of the shape of the ceramic shot is: the flat area of ​​the shot is 12.7×12.7 mm 2 ; The maximum number of projectiles with unqualified shapes allowed is 14.

[0102] The uniformity of the size of the glass pellets is: when the standard screen allows at most 0.5% of the weight to be retained, the number of meshes is 7 and the size of the mesh hole is 2.8mm. When the standard screen allows at most 20% of the weight to pass, the number of meshes is 12 and the size of the mesh hole is 1.7mm. The uniformity of the shape of the glass pellets is: the flat area of ​​the pellets is 25.4×25.4mm 2 ; The maximum number of projectiles with unqualified shapes allowed is 14.

[0103] Before the shot blasting process, check whether the nozzle is usable and ensure that the nozzle has no obvious damage and uneven wear.

[0104] Step 4, polishing:

[0105] The polishing is to polish the outer surface of the cathode roller after the shot blasting, including rough polishing and fine polishing.

[0106] Ⅰ Rough polishing.

[0107] After the shot blasting is completed, the cathode roller is transferred from the shot blasting room to the grinding machine so that the bearing and the bearing seat fit tightly. Turn on the grinding machine and detect that the circular runout of the copper sleeves at both ends is ≤0.05mm. A 120# PVA grinding wheel is used for rough blasting. The process parameters of the rough blasting are set as follows: the cathode roller speed is 4-5r / min, the grinding wheel speed is 700r / min, the grinding wheel feed is 10-12mm / r, and the flexible grinding head cylinder pressure is 0.2MPa.

[0108] Turn on the spray device switch and use a diamond pen to grind the roundness of the PVA grinding wheel surface. Face the knife at the end of the cathode roller and start rough polishing. Rough polish 3 to 5 times until there is no shot blasting mark on the surface of the cathode roller.

[0109] The grinding process is to move the PVA grinding wheel to the vicinity of the diamond pen, face the knife at the end of the PVA wheel, and start grinding. The outer cylindrical surface of the PVA grinding wheel is required to be completely ground. The grinding process parameters are set as follows: the grinding wheel speed is 500r / min, and the grinding wheel feed is 5mm / r. The diamond pen is located at one end of the grinding machine track.

[0110] Ⅱ Fine polishing.

[0111] After the rough polishing, 220# PVA grinding wheel is used for fine polishing. The process parameters of the fine polishing are set as follows: cathode roller speed is 4-5r / min, grinding wheel speed is 800r / min, grinding wheel feed is 5-6mm / r, and flexible grinding head cylinder pressure is 0.1MPa.

[0112] Use diamond pen to grind the roundness of PVA grinding wheel surface, face the knife at the end of cathode roller, and start fine polishing. Fine polish 3 to 5 times until there are no surface defects such as diagonal lines, color difference, bright spots, etc. on the surface of cathode roller, and measure the surface roughness to reach Ra0.3 or less.

[0113] The grinding process is to move the PVA grinding wheel to the vicinity of the diamond pen, face the knife at the end of the PVA grinding wheel, and start grinding. The outer cylindrical surface of the PVA grinding wheel is required to be completely ground. The grinding process parameters are set as follows: the grinding wheel speed is 500r / min, and the grinding wheel feed is 5mm / r. The diamond pen is located at one end of the grinding machine track.

[0114] Table 5 Process parameters of each embodiment in step 4

[0115]

[0116] At this point, the outer surface strengthening process of cathode rollers with diameters of 2700mm to 3600mm has been completed.

Claims

1. A method for strengthening the surface of a cathode roller, characterized in that: The specific process is: Step 1, turning: The turning process of the outer surface of the cathode roller blank includes rough turning and fine turning; Ⅰ Rough turning: After rough turning, the cathode roller blank diameter needs to be 2mm larger than the final size, leaving a 1mm allowance for fine turning; the surface roughness is less than Ra3.2; Ⅱ Fine turning: Finish turning the circumferential surface of the cathode roller blank to obtain a cathode roller blank; After finishing, the outer diameter of the cathode roller blank has a machining allowance of 1mm, of which 0.5mm is for shot blasting and grinding. The surface roughness of the cathode roller blank is less than Ra1.6, the coaxiality is ≤0.05mm, the roundness is ≤0.05mm, and the straightness is ≤0.05mm; Step 2, Grinding: The grinding is to grind the outer surface of the cathode roller blank after turning, including rough grinding and fine grinding; Ⅰ Rough grinding; Use 40# PVA grinding wheel for rough grinding; Turn on the spray device switch, use diamond pen to grind the roundness of the PVA grinding wheel surface; Face the cathode roller end with the knife and start rough grinding; Rough grinding 5 to 10 times; Get the rough ground cathode roller blank; Ⅱ Fine grinding; Use 60# PVA grinding wheel to fine-grind the cathode roller blank after rough grinding; use diamond pen to grind the surface roundness of PVA grinding wheel, face the knife at the end of cathode roller, and start fine grinding; fine grinding 5 to 10 times, so that the surface of cathode roller blank reaches below Ra0.8; Step 3, shot blasting: Shot blasting is performed on the outer surface of the cathode roller blank that has completed the grinding process; the shot blasting process includes primary shot blasting and secondary shot blasting; Ⅰ One shot blasting process; shielding the two end faces of the cathode roller blank, and shielding the protective shaft, copper sleeve and titanium sleeve; Lift the cathode roller blank to the shot blasting station so that the bearing and the bearing seat fit tightly; Use ceramic shot as the projectile for a shot blasting process; After one shot blasting is completed, use cotton yarn or compressed air to blow away the remaining projectiles and dust on the surface of the cathode roller; the shot blasting surface coverage rate is 100%; Ⅱ Secondary shot blasting; After the first shot blasting is completed, glass shot is used as the shot for the second shot blasting. After the second shot blasting is completed, cotton yarn or compressed air is used to blow away the shot and dust remaining on the surface of the cathode roller blank, and the shot blasting surface coverage rate is 100%. After the shot blasting is completed, a semi-finished product of the cathode roller is obtained; Step 4, Polishing: The polishing is to polish the outer surface of the cathode roller semi-finished product after shot blasting, including rough polishing and fine polishing; Ⅰ Rough polishing; Use 120# PVA grinding wheel for rough polishing; Turn on the spray device switch and use a diamond pen to grind the roundness of the PVA grinding wheel surface; rough polish 3 to 5 times until there is no shot blasting mark on the surface of the cathode roller; Ⅱ Fine polishing; Selecting a 220# PVA grinding wheel to perform fine polishing on the roughly polished cathode roller blank; Use diamond pen to grind the surface roundness of PVA grinding wheel; polish 3 to 5 times until there is no surface defect on the cathode roller and the surface roughness is less than Ra0.3; At this point, the processing of the outer surface of the cathode roller with a diameter of 2700mm to 3600mm has been completed.

2. The method for strengthening the surface of a cathode roller according to claim 1, characterized in that: In the turning process described in step 1, during rough turning, the rotation speed of the cathode roller blank is 8-10 r / min, the feed rate is 0.4-0.5 mm / r, and the turning depth is 2 mm; During the fine turning process, the rotation speed of the cathode roller blank is 10-12 r / min, the feed rate is 0.2-0.3 mm / r, and the turning depth is 0.5 mm.

3. The method for strengthening the surface of a cathode roller according to claim 1, characterized in that: The process parameters of the rough grinding process are: the cathode roller blank rotation speed is 3-4r / min, the grinding wheel rotation speed is 500r / min, the grinding wheel feed rate is 20-25mm / r, and the flexible grinding head cylinder pressure is 0.3MPa; The process parameters of the fine grinding are: the cathode roller blank rotation speed is 3-4r / min, the grinding wheel rotation speed is 600r / min, the grinding wheel feed rate is 15-20mm / r, and the flexible grinding head cylinder pressure is 0.2MPa.

4. The method for strengthening the surface of a cathode roller according to claim 1, characterized in that: During the one shot blasting process, the cathode roller blank rotation speed is 0.5-1r / min, the nozzle moving speed is 2-3.7mm / r, the projectile speed is 150m / s, the projectile angle is 90°, and the projectile distance L=100mm; During the secondary shot blasting, the rotation speed of the cathode roller blank is 1-1.2 r / min, the nozzle moving speed is 1.9-2.1 mm / r, the shot speed is 250 m / s, the projectile angle is 90°, and the projectile distance is 100 mm.

5. The method for strengthening the surface of a cathode roller according to claim 1, characterized in that: The uniformity of the size of the ceramic shot is: when the standard screen allows a maximum of 0.5% of the weight to be retained, the number of meshes is 14 and the size of the mesh hole is 1.1 mm; when the standard screen allows a maximum of 20% of the weight to be passed, the number of meshes is 20 and the size of the mesh hole is 0.85 mm; the uniformity of the shape of the ceramic shot is: the flat area of ​​the shot is 12.7×12.7 mm 2 ; The maximum number of projectiles with unqualified shapes allowed is 14.

6. The method for strengthening the surface of a cathode roller according to claim 1, characterized in that: The uniformity of the size of the glass pellets is: when the standard screen allows a maximum of 0.5% of the weight to be retained, the number of meshes is 7 and the size of the mesh hole is 2.8 mm; when the standard screen allows a maximum of 20% of the weight to be passed, the number of meshes is 12 and the size of the mesh hole is 1.7 mm; the uniformity of the shape of the glass pellets is: the flat area of ​​the pellets is 25.4×25.4 mm 2 ; The maximum number of projectiles with unqualified shapes allowed is 14.

7. The method for strengthening the surface of a cathode roller according to claim 1, characterized in that: In step 4, during the rough polishing, the cathode roller semi-finished product rotation speed is 4-5 r / min, the grinding wheel rotation speed is 700 r / min, the grinding wheel feed rate is 10-12 mm / r, and the flexible grinding head cylinder pressure is 0.2 MPa; During the fine polishing, the cathode roller speed is 4-5 r / min, the grinding wheel speed is 800 r / min, the grinding wheel feed is 5-6 mm / r, and the flexible grinding head cylinder pressure is 0.1 MPa.

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