Method for coating pretreatment of band saw blade

Abstract

The invention relates to a method for band saw blade coating pretreatment, which comprises the following steps: saw cutting passivation treatment is carried out on a band saw blade to be coated, a chamfer of 20-100 microns is formed at a tooth tip, and the saw cutting passivation treatment comprises the step of sawing a saw cutting material by adopting the band saw blade. According to the technical scheme, the hardness of the sawteeth can be effectively improved, the service life of the band saw blade is prolonged, and the sawing efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of band saw blade production, and particularly to a method for pre-treatment before coating of a band saw blade. Background Art

[0002] Through coating treatment, the service life and sawing efficiency of the band saw blade can be improved. The quality of the coating treatment is closely related to the pre-treatment of the band saw blade. At present, there are still different defects in the pre-treatment process of the band saw blade, resulting in uneven quality of the produced coated band saw blades, and even negative effects after coating. Therefore, it is necessary to solve this problem to improve the quality of the band saw blade. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for pre-treatment before coating of a band saw blade, which can effectively improve the quality of the saw blade.

[0004] The technical solution adopted by the present invention is as follows.

[0005] A method for pre-treatment before coating of a band saw blade, characterized in that it includes performing sawing passivation treatment on the band saw blade to be coated, forming a chamfer of 20 - 100 μm at the tooth tip, and the sawing passivation treatment includes using the band saw blade to saw the sawing material.

[0006] A further solution is to perform welding treatment on the band saw blade so that the head and tail ends of the band saw blade are connected as a whole, and then install the band saw blade on a saw blade machine for sawing passivation treatment.

[0007] The sawing material is 45# steel.

[0008] During the sawing passivation treatment, adjust the linear speed of the band saw blade to 40 - 50 m / min and the feed rate to 10 - 20 mm / min.

[0009] During the sawing passivation treatment, the band saw blade runs for 2 - 5 cycles.

[0010] The length of the band saw blade is 75 - 100 m.

[0011] During the welding treatment, a spot welder is used to weld the band saw blade, and after the welding treatment, tempering, weld joint grinding, and weld joint sandblasting treatments are carried out in sequence.

[0012] Band saw blades of different models are welded and tempered according to the following parameters.

[0013] Saw blade type Butt welding current (A) Butt welding cooling time (s) First stage tempering temperature (℃) First stage tempering time (s) Second stage tempering temperature (℃) Second stage tempering time (s) Third stage tempering temperature (℃) Third stage tempering time (s) 19 65±3% 0 580±5 3 590±5 15 570±5 5 27 68±3% 1.5 580±5 3 590±5 15 570±5 5 34 70±3% 1.5 540±5 3 550±5 20 530±5 5 41 80±3% 1.5 550±5 3 560±5 25 540±5 5 54 85±3% 1.5 560±5 3 570±5 35 550±5 5 67 95±3% 1.5 580±5 3 590±5 35 570±5 5 After the sawing passivation treatment, cut the band saw blade, rewind it in the way that the back of the tooth faces forward to form a coil, weld a leading strip at the outermost joint of the coil, and then perform sandblasting treatment, cleaning treatment, drying treatment, and winding and assembling treatment on the band saw blade in sequence.

[0014] A further solution is that during the passivation treatment, cleaning treatment, and drying treatment, the band saw blade is conveyed in a state where the back of the teeth is in front and the tips of the teeth are behind along the conveying direction.

[0015] The sandblasting material used for sandblasting treatment is white fused alumina or brown fused alumina of 240 - 2000#. During sandblasting treatment, the mass ratio of water to sand is controlled at 5:1 - 10:1; the sandblasting pressure is 0.2 - 0.4 MPa; the linear speed of the band saw blade conveyance is 5 - 10 m / min. The number of spray guns is set to 2 - 6, the number of forward spray guns is 1 - 3; the number of reverse spray guns is 1 - 3, the distance between the spray gun and the saw teeth is 50 - 200 mm; the spray gun angle is 30 - 90 degrees.

[0016] The band saw blade is subjected to a cleaning treatment using a spraying process, and the cleaning treatment includes a chemical agent cleaning treatment and a pure water cleaning treatment carried out in sequence.

[0017] The cleaning solution used for the chemical agent cleaning treatment is an aqueous solution containing 1% NaOH by mass percentage and 0.2% Anticorr PLUS rust inhibitor by mass percentage, and the temperature of the cleaning solution is 55 - 65 °C.

[0018] The thickness of the guiding strip is the same as that of the band saw blade, the height is 2 - 3 mm lower than the height of the band saw blade, and the material is stainless steel or spring steel.

[0019] The winding and assembling treatment includes winding the accompanying tape and the band saw blade into a disk shape on the coating disk, and fixing the tails of the accompanying tape and the band saw blade through a fixing component. After winding and forming, the saw teeth of the band saw blade are arranged away from the coating disk, and the accompanying tape and the coated band saw blade are arranged in an alternating and spaced manner from the inside to the outside. The height of the accompanying tape is 2 - 4 mm lower than the height of the tooth tips. The material of the accompanying tape is stainless steel or carbon steel. The band saw blade consists of a blade body part and saw teeth on the blade body part, and the accompanying tape wraps the blade body part of the band saw blade.

[0020] The coating treatment is ion plating, and the coating film layer includes superhard TiN, AlCrN, AlTiN, TiSiN, TiAlSiN, TiCrAlSiN, DLC, with a hardness of HV2500 - HV4000 and a film thickness of 2 - 6 μm.

[0021] The above technical solution provided by the present invention can effectively improve the hardness of the saw teeth, and improve the service life and sawing efficiency of the band saw blade. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a process schematic diagram of the present invention.

[0023] Figure 2 It is a schematic diagram of the saw tooth orientation when the band saw blade is conveyed.

[0024] Figure 3It is a schematic structural diagram of forward spraying and reverse spraying.

[0025] Figure 4 It is a partial structural schematic diagram after the band saw blade and the coating companion tape are wound.

[0026] Figure 5 It is a schematic diagram of the principle of the saw blade sawing passivation machine.

[0027] The corresponding relationship between the drawing number and the component is as follows: 10 - band saw blade, 11 - driving wheel, 12 - driven wheel, 13 - band saw blade winding mechanism, 14 - sawing material. Specific implementation mode

[0028] In order to make the purpose and advantages of the present invention clearer, the present invention will be specifically described below in conjunction with embodiments. It should be understood that the following text only describes one or several specific implementation manners of the present invention, and does not strictly limit the scope of protection specifically claimed by the present invention.

[0029] As used herein, terms such as "parallel", "perpendicular", etc. are not limited to their strict geometric definitions, but include tolerances for machining or human errors that are reasonable and inconsistent.

[0030] The quality of the band saw blade coating treatment is closely related to the pretreatment process. Through passivation treatment, the tooth tips can be passivated, so that the force on the saw blade is uniform during cutting, reducing the probability of chipping, and having an obvious effect on improving the service life of the saw blade. In addition, pretreatment can remove surface oxides and contaminants, which is a necessary condition for improving the bonding force of the coating. The present invention mainly focuses on the improvement and research and development of the pretreatment before coating, and the equipment and operation parameters used for the coating treatment can be the same as the existing implementation manners.

[0031] As Figure 1 shown, the band saw blade coating process provided by the present invention specifically includes the following operations.

[0032] Incoming material inspection: Use a 5 - 40× magnifying glass with a lamp to check the tooth tip state of the incoming band saw blade. The inspection items include the chipping and rusting state of the incoming edge. The upper limit of the chipping amount at the tooth tip is 0.2 mm, and the number of chipped teeth cannot exceed 5% of the total number of teeth. For band saw blades with floating rust on the surface and no obvious damage to the substrate, there is no need for control. Chipped teeth on the band saw blade will affect the stability of sawing, resulting in breakage of the band due to excessive resistance or skewing due to uneven force. It is difficult to play a good role after coating, so incoming material control is particularly critical. Band saw blades with floating rust on the surface and no obvious damage to the substrate can be removed by sandblasting in the later stage, which has no impact on coating.

[0033] Saw Blade Welding: After the incoming saw blade coil is unrolled, the butt welder is used to weld the head and tail, temper, grind the weld joint, and perform sandblasting treatment on the weld joint to prepare for the subsequent sawing passivation. It is an essential process for the operation of the sawing passivation equipment. The welding requirements are that the belt should not break during the sawing and running-in process, there should be no weld bead residue at the weld joint, and the length needs to match the sawing passivation equipment. Saw blade welding is an essential process to meet the requirements of the sawing passivation equipment. Different welding processes are used for saw blades of different sizes, and the specific parameters are as follows.

[0034] Table 1 Operating Parameters of Welding Treatment and Tempering Treatment Saw blade type Butt welding current (A) Butt welding cooling time (s) First stage tempering temperature (℃) First stage tempering time (s) Second stage tempering temperature (℃) Second stage tempering time (s) Third stage tempering temperature (℃) Third stage tempering time (s) 19 65±3% 0 580±5 3 590±5 15 570±5 5 27 68±3% 1.5 580±5 3 590±5 15 570±5 5 34 70±3% 1.5 540±5 3 550±5 20 530±5 5 41 80±3% 1.5 550±5 3 560±5 25 540±5 5 54 85±3% 1.5 560±5 3 570±5 35 550±5 5 67 95±3% 1.5 580±5 3 590±5 35 570±5 5 Sawing Passivation: For new uncoated saw blades, a running-in stage is often experienced during normal sawing, that is, running at a lower wire speed and feed for a period of time. Generally, the sawing wire speed and feed during running-in are 50% of the normal sawing speed and feed. Then, the speed and feed are increased by 5% after each cut. Saw blade running-in can reduce the chipping of the tooth tips, remove unnecessary burrs, and evenly distribute the force on the tooth tips, thus achieving the best working state and effectively increasing the service life of the saw blade. Similar to the principle of sawing and running-in, in order to improve the operation efficiency, in the present invention, the welded saw blade is installed on the saw blade machine before coating. The length of the saw blade is usually the length of the coil, that is, 75 - 100 m. According to different saw blade models and lengths, the corresponding saw blade sawing passivation machine is used, such as Figure 5 shown. The wire speed of the saw blade of the sawing passivation equipment is 40 - 50 m / min, the feed is 10 - 20 mm / min, the sawing material is 45# steel, and the entire saw blade needs to go through 2 - 5 cycles.

[0035] Sawing passivation can effectively remove the burrs and sharp tooth tips at the tooth tips, make the left and right tooth spacing uniform, and can form a chamfer of 20 - 100 μm at the tooth tips. The subsequent super-hard coating is applied to the already run-in saw blade, reducing the running-in time of the coated saw blade, and reducing the risk of premature peeling of the local coating due to uneven stress on the coating. The sawing efficiency and sawing life are effectively improved.

[0036] The saw blade machine can be various equipment that can enable the band saw blade 10 to perform sawing operation. Specifically, equipment with the same and similar principles as shown in Figure 5 can be used. It consists of a driving wheel 11, a driven wheel 12, and a band saw blade winding mechanism 13. The straight long saw body between the driving wheel and the driven wheel saws the round bar-shaped sawing material 15.

[0037] Rewinding Treatment: For the movement direction of the saw blade, the coils of the saw blade generally have two forms, namely "tooth tip leading" and "tooth back leading", as shown in Figure 2As shown in the figure. During the sandblasting treatment, cleaning, and drying processes of the saw blade, if the tooth tips are in the front, when the saw blade passes through the slit of the sandblasting, cleaning, and drying line, the cutting edges will hit the side wall of the slit, resulting in jamming of the production line, chipping of the saw blade cutting edges, or damage to the slit. This should be avoided during the production process. If the tooth backs are in the front, there will be no cutting tendency, and no damage will be caused to the saw blade and the production line, so the rewinding process is not required. For the incoming saw blades with tooth tips in the front, the rewinding process is needed to make the tooth backs in the front, that is, just swap the head and tail positions of the saw blade using two working disks. The rewinding process can make the tooth backs of the saw blade in the front, and there will be no cutting tendency when passing through the production line, thus avoiding damage to the saw blade and the production line.

[0038] Leading strip welding: After sawing and passivation, the saw blade needs to be cut, rewound into a coil in the way that the tooth backs are in the front, and the leading strip is welded at the joint of the outermost circle of the coil. To ensure the consistency of saw blade production and avoid situations such as missed spraying, over-spraying, or uneven sandblasting, a 10 - 15 m long leading strip (ensuring the length exceeds the total length of the production line) needs to be welded to the front end of the saw blade after rewinding and before sandblasting and passivation. After the equipment runs, it will not directly spray on the saw blade first, but on the leading strip. The thickness of the leading strip is the same as that of the saw blade, the height is 2 - 3 mm lower than that of the saw blade, and the material is stainless steel or spring steel. The leading strip first passes through the sandblasting line, cleaning line, and drying line, which can avoid situations such as missed spraying, over-spraying, or uneven sandblasting on the front-end saw blade. In addition, when winding on the coating disk, the leading strip will wind around the innermost circle of the coating disk, forming a certain thickness, providing a certain buffer for the inner saw blade, and avoiding excessive deformation and overflow coating of the saw blade.

[0039] Sandblasting treatment: Adjust the left and right guide wheels of the sandblasting machine according to the height of different saw blades to ensure that the tooth tips are completely exposed on the sandblasting platform. The sandblasting material is 240 - 2000 # white fused alumina or brown fused alumina; the maximum water-sand mass ratio is 10:1, and the minimum is 5:1; the sandblasting pressure is 0.2 - 0.4 MPa; the linear speed of the saw blade is 5 - 10 m / min; the number of spray guns is 2 - 6; the number of forward spray guns (specified as the spray guns facing the direction of the tooth tips, as Figure 3 shown) is 1 - 3; the number of reverse spray guns (specified as the spray guns facing away from the direction of the tooth tips, or facing the direction of the tooth backs, as shown in the following figure) is 1 - 3; the gun base distance is 50 - 200 mm; the spray gun angle is 30 - 90 degrees; according to the different quantities of saw blades sandblasted, the water-sand replacement cycle is 3 - 5 days. The sandblasting rust and dirt removal process can remove oxides and pollutants. Through the combination of sandblasting materials, the number of spray guns, spray gun angles, forward and reverse spraying, sandblasting pressure, and gun base distance, different degrees of cleaning effects of the saw blade can be achieved, providing a guarantee for the bonding force of the coating process.

[0040] Cleaning process: Sandblasting, spraying, and drying are combined in a production line. After the sandblasting process is completed, the saw blade immediately passes through the spraying line, which includes one chemical spraying tank and two pure water spraying tanks to remove residual sand grains and contaminants on the surface. Chemical ratio: 1% NaOH by mass fraction + 0.2% Anticorr PLUS rust inhibitor by mass fraction; temperature: 55 - 65 °C; the linear speed of the saw blade passing through is the same as that of the sandblasting process. After chemical spraying, two pure water sprays are used to make the saw blade cleaner. After sandblasting, there are a small amount of sand grains and contaminants remaining on the surface of the saw blade, which can be removed completely and rust-proofed for a short time through the spraying and cleaning process, providing a good bonding force for the coating.

[0041] Drying process: The saw blade after spraying and cleaning passes through the drying tank, and high-temperature and high-speed air knives are used to remove the moisture on the surface. The temperature is 100 - 150 °C, the wind speed is 20 - 60 m / s, the width of the air outlet is 2 mm, and the number of air knives is 6. The high-temperature and high-speed air knives remove the moisture on the surface, making the saw blade dry quickly.

[0042] Winding and assembling process: Workers wear masks, dust-free gloves, and headgear. After the sandblasting machine has run for 5 minutes, set the linear speed of the saw blade at 0.5 - 10 m / min according to the pretreatment sandblasting process sheet, and click the counterclockwise or clockwise speed tracking on the linear speed meter. The saw blade and the accompanying tape are wound around the coating disk synchronously layer by layer, with one layer of saw blade and one layer of accompanying tape, and ensure that the saw blade and the accompanying tape are close to the large disk during operation. After winding, use a steel wire to tie the accompanying tape and the saw blade tightly at 5 cm from the tail of the accompanying tape, as Figure 4 shown, to prevent the end of the saw blade from spreading and touching the furnace wall to cause a short circuit inside the coating furnace. The installed saw blade is fixed with large disk fixing screws and saw blade fixing screws to prevent gaps from forming inside the saw blade, which may cause overcoating. After coating the tooth back of the saw blade, it will affect the sawing fatigue life. The role of the accompanying tape is to fix the coated area at the tooth tip area of the saw blade to prevent coating on the tooth back. With the cooperation of the fixing fixture, it can prevent the saw blade from spreading or forming gaps during the coating heating process.

[0043] Vacuum coating: The coating process includes pumping, heating, ion cleaning, metal etching, primer layer, transition layer, and functional layer. Superhard coatings such as TiN, AlCrN, AlTiN, TiSiN, TiAlSiN, TiCrAlSiN, DLC, etc. are coated on the cutting edge of the saw blade, with a hardness range of HV2500 - 4000 and a film thickness of 2 - 6 μm. The superhard coating can improve the wear resistance, heat insulation ability, reduce the friction coefficient, and provide certain corrosion resistance of the saw blade, thereby improving the cutting efficiency and service life of the saw blade.

[0044] Example 1: Prepare a TiSiN coating on a 34 2 / 3 - tooth bimetal band saw blade, which is suitable for cutting hard materials such as stainless steel and die steel.

[0045] Use a 10× magnifying glass with a light to inspect the tip state of the incoming band saw blade. The inspection items include the chipping and rusting state of the incoming blade edge. The upper limit of the chipping amount at the tip is 0.2 mm, and the number of chipped teeth cannot exceed 5% of the total number of teeth. For band saw blades with floating rust on the surface and no obvious damage to the base material, there is no need for control.

[0046] After the incoming saw blade coil is unwound, the saw blade welding is to weld the head and tail, temper, grind the weld, and sandblast the weld using a spot welder to prepare for the subsequent sawing passivation. It is a necessary process for the sawing passivation equipment to operate. The welding requirement is that the saw blade should not break during the sawing running-in process, and there should be no residual weld beads at the weld. The length needs to match the sawing passivation equipment. The specific operation parameters are as follows: Table 2 Technical parameters of welding treatment and tempering in Example 1 Saw blade type Butt welding current (A) Butt welding cooling time (s) First stage tempering temperature (℃) First stage tempering time (s) Second stage tempering temperature (℃) Second stage tempering time (s) Third stage tempering temperature (℃) Third stage tempering time (s) 34 70 1.5 540 3 550 20 530 5 Use the corresponding sawing equipment for the length. The linear speed of the saw blade on the sawing machine is 45 m / min, the feed rate is 18 mm / min, the sawing material is 45# steel, and the entire saw blade needs to go through 3 cycles.

[0047] After sawing passivation, the saw blade should be cut, rewound into a coil in the way that the tooth back is in front, and an extension belt is welded at the outermost joint of the coil. That is, a 15 m long extension belt is welded at the front end of the saw blade. After the equipment runs, it will not directly spray on the saw blade first, but on the extension belt. The thickness of the extension belt is the same as that of the saw blade, the height is 2 mm lower than that of the saw blade, and the material is stainless steel or spring steel.

[0048] Adjust the left and right guide wheels of the sandblasting machine according to the height of different saw blades to ensure that the tooth tips are completely exposed on the sandblasting platform. The sandblasting material is 600# white fused alumina or brown fused alumina; the mass ratio of water to sand is 10:1; the sandblasting pressure is 0.35 MPa; the linear speed of the saw blade is 5 m / min; the number of spray guns is 2; the number of positive spray guns is 1; the number of negative spray guns is 1; the distance between the gun base and the saw blade is 150 mm; the spray gun angle is 45 degrees; the replacement cycle of water and sand is 4 days.

[0049] The sandblasting passivation, spraying, and drying are in a combined line. After the sandblasting passivation process is completed, the saw blade immediately passes through the spraying line. The spraying line includes a chemical spraying tank and two pure water spraying tanks to remove the residual sand grains and pollutants on the surface. Chemical ratio: 1% NaOH by mass fraction + 0.2% Anticorr PLUS rust inhibitor by mass fraction; temperature: 60 °C; the linear speed of the saw blade passing through is the same as that of sandblasting passivation. After chemical spraying, 2 pure water sprayings are used to make the saw blade cleaner.

[0050] The saw blade after spraying and cleaning passes through the drying tank, and the surface moisture is removed by high-temperature and high-speed air cutting. The temperature is 150 °C, the wind speed is 60 m / s, the width of the air outlet is 2 mm, and the number of air knives is 6.

[0051] Workers wear masks, dust-free gloves and headgear. After the sandblasting machine runs for 5 minutes, set the saw blade linear speed at 8 m / min according to the pretreatment sandblasting process sheet. Click the counterclockwise or clockwise speed tracking on the linear speed meter. The saw blade and the accompanying tape are wound around the coating disk synchronously layer by layer, with one layer of saw blade and one layer of accompanying tape. During the operation, ensure that the saw blade and the accompanying tape are tightly attached to the large disk. After the winding is completed, tie the accompanying tape and the saw blade tightly with steel wire at a position 5 cm from the tail of the accompanying tape, as Figure 4 shown, to prevent the end of the saw blade from spreading and touching the furnace wall, causing a short circuit inside the coating furnace. Fix the installed saw blade with the large disk fixing screws and special saw blade fixing screws to prevent gaps inside the saw blade from causing overplating.

[0052] Inside the vacuum coating equipment, after evacuation, heating, ion cleaning, metal etching, primer layer, transition layer, and functional layer, a super-hard TiSiN coating with a hardness range of HV3500 - 4500 and a film thickness of 5 μm is plated on the saw blade edge.

[0053] Example 2: Prepare an AlTiN coating on a 41 2 / 3 - tooth bimetal band saw blade, which is suitable for cutting hard materials such as die steel and alloy steel.

[0054] Use a 10× magnifying glass with a light to check the tip state of the incoming band saw blade. The inspection items include the notch and rust state of the incoming edge. The upper limit of the notch amount at the tip is 0.2 mm, and the number of broken teeth cannot exceed 5% of the total number of teeth. For band saw blades with floating rust on the surface and no obvious damage to the substrate, there is no need for control.

[0055] Saw blade welding is carried out after the incoming saw blade coil is unwound. Use a spot welder to weld the head and tail, temper, grind the weld, and perform sandblasting treatment on the weld to prepare for the subsequent sawing passivation. It is a necessary process for the sawing passivation equipment to operate. The welding requirements are that the band cannot break during the sawing and running - in process, there should be no weld bead residue at the weld, and the length needs to match the sawing passivation equipment. The specific operating parameters are as follows: Table 3 Technical parameters of welding treatment and tempering in Example 2 Saw blade type Butt welding current (A) Butt welding cooling time (s) First stage tempering temperature (℃) First stage tempering time (s) Second stage tempering temperature (℃) Second stage tempering time (s) Third stage tempering temperature (℃) Third stage tempering time (s) 41 80 1.5 550 3 560 25 540 5 Install the welded saw blade on the sawing machine. The length of the saw blade is usually the length of the coil, that is, 75 - 100 m. Use the corresponding sawing equipment according to different saw blade models and lengths. The linear speed of the saw blade on the sawing machine is 40 m / min, the feed rate is 15 mm / min, the sawing material is 45# steel, and the entire saw blade needs to go through 2 cycles.

[0056] After sawing and passivation, the saw blade needs to be cut, and rewound in the way that the back of the teeth is in front to form a coiled strip. The leading strip is welded at the joint of the outermost circle of the coiled strip. That is, a 15m long leading strip is welded at the front end of the saw blade (ensuring that the length exceeds the total length of the production line). After the equipment runs, it will not directly spray on the saw blade first, but on the leading strip. The thickness of the leading strip is the same as that of the saw blade, the height is 2.5mm lower than that of the saw blade, and the material is stainless steel or spring steel.

[0057] Adjust the left and right guide wheels of the sandblasting machine according to the height of different saw blades to ensure that the tooth tips are completely exposed on the sandblasting platform. The sandblasting material is 600# white fused alumina or brown fused alumina; the mass ratio of water to sand is 10:1; the sandblasting pressure is 0.35MPa; the linear speed of the saw blade is 8m / min; the number of spray guns is 2; the number of forward spray guns is 1; the number of reverse spray guns is 1; the gun base distance is 150mm; the spray gun angle is 45 degrees; the replacement cycle of water and sand is 4 days.

[0058] The sandblasting passivation, spraying, and drying are in a combined line. After the sandblasting passivation process is completed, the saw blade immediately passes through the spraying line, which includes a chemical spraying tank and two pure water spraying tanks to remove the remaining sand grains and pollutants on the surface. Chemical ratio: 1% NaOH by mass fraction + 0.2% Anticorr PLUS rust inhibitor by mass fraction; temperature: 60°C; the linear speed of the saw blade passing through is the same as that of sandblasting passivation. After chemical spraying, 2 passes of pure water spraying are used to make the saw blade cleaner.

[0059] The saw blade after spray cleaning passes through the drying tank, and the surface moisture is removed by high-temperature and high-speed air cutting. The temperature is 150°C, the wind speed is 60m / s, the width of the air outlet is 2mm, and the number of air knives is 6.

[0060] The staff wear masks, dust-free gloves and headgear. After the sandblasting machine runs for 5 minutes, set the linear speed of the saw blade to 8m / min according to the pretreatment sandblasting process sheet, and click the counterclockwise or clockwise speed tracking on the linear speed meter. The saw blade and the accompanying tape are wound on the coating disk synchronously layer by layer of saw blade and layer of accompanying tape. During the operation, ensure that the saw blade and the accompanying tape are tightly attached to the large disk. After the winding is completed, use a steel wire to tie the accompanying tape and the saw blade tightly at 5cm from the tail of the accompanying tape, as Figure 4 shown, to prevent the end of the saw blade from spreading and touching the furnace wall to cause a short circuit inside the coating furnace. The installed saw blade is fixed with a large disk fixing screw and a special saw blade fixing screw to prevent gaps inside the saw blade from causing overplating.

[0061] Inside the vacuum coating equipment, after pumping, heating, ion cleaning, metal etching, underlayer, transition layer, and functional layer, a superhard AlTiN coating is deposited on the cutting edge of the saw blade, with a hardness range of HV3000 - 4000 and a film thickness of 6μm.

[0062] Example 3: Prepare an AlTiN coating on a 54 2 / 3 tooth bimetal band saw blade, suitable for cutting hard materials such as die steel and alloy steel Use a 20× magnifying glass with a light to inspect the tip state of the incoming band saw blade. The inspection items include the chipping and rusting state of the incoming blade edge. The upper limit of the chipping amount at the tip is 0.2 mm, and the number of chipped teeth shall not exceed 5% of the total number of teeth. For band saw blades with floating rust on the surface and no obvious damage to the base material, no control is required.

[0063] After the incoming saw blade coil is unwound, the saw blade welding is carried out using a spot welder to weld the head and tail, temper, grind the weld, and sandblast the weld, preparing for the subsequent sawing passivation. It is a necessary process for the sawing passivation equipment to operate. The welding requirements are that the band cannot break during the sawing running-in process, there should be no weld bead residue at the weld, and the length needs to match the sawing passivation equipment. The specific operating parameters are as follows: Table 4 Technical parameters of welding treatment and tempering in Example 3 Saw blade type Butt welding current (A) Butt welding cooling time (s) First stage tempering temperature (℃) First stage tempering time (s) Second stage tempering temperature (℃) Second stage tempering time (s) Third stage tempering temperature (℃) Third stage tempering time (s) 54 85 1.5 560 3 570 35 550 5 Install the welded saw blade on the saw blade machine. The length of the saw blade is usually the length of the coil, that is, 75 - 100 m. Select the corresponding sawing machine according to different saw blade models and lengths. Adjust the linear speed of the saw blade to 50 m / min, the feed speed to 20 mm / min, the sawing material is 45# steel, and the whole saw blade needs to go through 3 cycles.

[0064] After sawing passivation, cut the saw blade and rewind it into a coil in the way that the tooth back is in front. Weld the leader tape at the outermost joint of the coil. That is, weld a 15 - m long leader tape at the front end of the saw blade (ensure the length exceeds the total length of the production line). After the equipment starts running, it will not directly spray on the saw blade first, but on the leader tape. The thickness of the leader tape is the same as that of the saw blade, the height is 3 mm lower than that of the saw blade, and the material is stainless steel or spring steel.

[0065] Adjust the left and right guide wheels of the sandblaster according to different saw blade heights to ensure that the tooth tips are completely exposed on the sandblasting platform. The sandblasting material is 500# white corundum or brown corundum; the mass ratio of water to sand is 10:1; the sandblasting pressure is 0.35 MPa; the linear speed of the saw blade is 5 m / min; the number of spray guns is 4; the number of forward spray guns is 2; the number of reverse spray guns is 2; the gun base distance is 110 mm; the spray gun angle is 45 degrees; the water - sand replacement cycle is 3 days.

[0066] The sandblasting, spraying, and drying are in a combined line. After the sandblasting process is completed, the saw blade immediately passes through the spraying line. The spraying line includes a chemical spraying tank and two pure water spraying tanks to remove the residual sand grains and pollutants on the surface. Chemical ratio: 1% NaOH by mass fraction + 0.2% Anticorr PLUS rust inhibitor by mass fraction; temperature: 60°C; the linear speed of the saw blade passing through is the same as that of sandblasting. After chemical spraying, 2 - pass pure water spraying is used to make the saw blade cleaner.

[0067] The saw blade after spray cleaning passes through a drying tank, and high-temperature and high-speed air cutting is used to remove the moisture on the surface. The temperature is 150°C, the wind speed is 60 m / s, the width of the air outlet is 2 mm, and the number of air knives is 6.

[0068] The staff wear masks, dust-free gloves and headgear. After the sandblasting machine runs for 5 minutes, set the linear speed of the saw blade to 8 m / min according to the pretreatment sandblasting process sheet, click the counterclockwise or clockwise speed tracking on the linear speed meter, and the saw blade and the accompanying tape are wound around the coating disc synchronously layer by layer of saw blade and layer of accompanying tape. During the operation, ensure that the saw blade and the accompanying tape are tightly attached to the large disc. After the winding is completed, use a steel wire to tie the accompanying tape and the saw blade tightly at 5 cm from the tail of the accompanying tape, as Figure 4 shown, to prevent the end of the saw blade from spreading and touching the furnace wall to cause a short circuit inside the coating furnace. The installed saw blade is fixed with large disc fixing screws and saw blade fixing screws to prevent gaps from forming inside the saw blade and causing overcoating.

[0069] Move the wound band saw blade into the vacuum coating equipment, and through evacuation, heating, ion cleaning, metal etching, underlayer, transition layer, and functional layer, deposit a super-hard AlTiN coating on the cutting edge of the saw blade, with a hardness range of HV3000 - 4000 and a film thickness of 6 μm.

[0070] Detect the performance of the uncoated band saw blade and the coated band saw blade in Example 1, and the results are shown in the following table.

[0071] Table 5 Comparison results of performance parameters Saw blade type Passivation method Coating type and performance parameters Sawing cutting speed Sawing cutting feed Sawing material Diameter of sawing material (mm) Hardness of sawing material (HRC) Average sawing life (knives) Single-pass sawing time (min) 34 2 / 3 teeth Naked saw No coating 50 m / min 25 mm / min 45# steel 110 38 (core) + 60 (outer ring) 2.5 4.4 34 2 / 3 teeth Sawing passivation AlTiN, HV3000, 6 μm 50 m / min 25 mm / min 45# steel 110 38 (core) + 60 (outer ring) 11 4 As can be seen from the above, although the ordinary band saw blade (bare saw) has a low production cost, its cutting life for hard materials is short. The coated band saw blade has a cutting life 4.4 times that of the ordinary band saw blade, and the cutting efficiency is increased by 9%.

[0072] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention. The structures, devices, and operation methods not specifically described and explained in the present invention, unless otherwise specified and limited, are implemented according to the conventional means in the art.

Claims

1. A method for pre-treatment of band saw blade coating, characterized in that: The method comprises performing sawing passivation treatment on the band saw blade to be coated, and the sawing passivation treatment comprises using the band saw blade to saw the sawing material.

2. The method for pre-treatment of band saw blade coating according to claim 1, characterized in that: The band saw blade is welded so that the head and tail ends of the band saw blade are connected as a whole, and then the band saw blade is installed on a saw blade machine for sawing passivation treatment.

3. The method for pre-treatment of band saw blade coating according to claim 2, characterized in that: The sawing material is 45# steel.

4. The method for pre-treatment of band saw blade coating according to claim 2, characterized in that: During sawing passivation treatment, adjust the linear speed of the band saw blade to 40-50m / min and the feed rate to 10-20mm / min.

5. The method for pre-treatment of band saw blade coating according to claim 2, characterized in that: When sawing the passivation treatment, the band saw blade runs 2-5 cycles.

6. The method for pre-treatment of band saw blade coating according to claim 2, characterized in that: The length of the band saw blade is 75 to 100 m.

7. The method for pre-treatment of band saw blade coating according to claim 2, characterized in that: During the welding process, a butt welding machine is used to weld the band saw blades. After welding, tempering, weld grinding and weld sandblasting are carried out in sequence.

8. The method for pre-treatment of band saw blade coating according to claim 7, characterized in that: Different types of band saw blades are welded and tempered according to the following parameters: 。 9. The method for pre-treatment of band saw blade coating according to claim 2, characterized in that: After the sawing passivation treatment, the band saw blade is cut and rewound with the back of the teeth facing forward to form a coil. The lead tape is welded at the outermost joint of the coil, and then the band saw blade is sandblasted, cleaned, dried and coiled and assembled in sequence.

10. The method for pre-treatment of band saw blade coating according to claim 9, characterized in that: The blasting material used for sandblasting is 240-2000# white corundum or brown corundum.

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