A method for preventing the galvanized strip product from being scratched by the disc shear blade and suppressing the blade from being nubbed by the condensed zinc powder in the galvanizing line disc shear cutting

Abstract

The present application belongs to the technical field of galvanized strip processing, and particularly relates to a galvanizing line disc shear cutting method for preventing disc shear blade from scratching galvanized plate finished strip and inhibiting zinc powder condensation and nodule formation on the blade. The method comprises the steps of cutting preparation, cutting operation and post-cutting cleaning. In the cutting preparation, the upper blade is arranged outside the lower blade to only contact the scrap edge, the outer circle radius of the upper rubber ring is 3mm smaller than the radius of the upper blade, and the outer circle radius of the lower rubber ring is 0.05-0.08mm larger than the radius of the lower blade to achieve suspended material dragging, thereby eliminating blade marks and rubber ring marks from the physical structure. During the cutting operation, high-pressure air blowing is performed at an angle of 45° along the strip movement direction at the inlet side, and a scraper and lubricating device integrated structure is used to deliver SMD40 high-volatility cleaning agent at a rate of 1-3 drops per second to the occlusion of the cutting edge to achieve simultaneous scraping, lubricating and cooling, thereby inhibiting zinc powder condensation and nodule formation. The present application reduces the printing defect rate to below 0.5%, reduces the nodule formation rate to below 0.8%, prolongs the service life of the cutting edge by more than 60%, and significantly improves the surface quality of the galvanized plate and the production continuity.

Description

Technical Field

[0001] This invention belongs to the field of galvanized steel strip processing technology, and specifically relates to a galvanized steel strip cutting method using a disc shear to prevent the disc shear blades from scratching the finished galvanized steel strip and to inhibit zinc powder from condensing and forming blade nodules. Background Technology

[0002] Galvanized steel strip is widely used in automobile manufacturing, home appliances, electronics, and construction due to its excellent corrosion resistance. As a core edge-cutting device on the galvanizing production line, the disc shear is primarily responsible for removing edge defects in the steel strip and precisely controlling the width of the finished product. However, in actual shearing operations, the characteristics of the zinc layer on the surface of the galvanized steel strip have presented two key technical challenges that have long plagued the industry, severely impacting product quality and production efficiency.

[0003] Firstly, the scratching problem caused by the disc shear blades on finished galvanized steel strips is significant. The galvanized layer is relatively brittle, and during the shearing process, the contact between the blades and the finished strip, along with the pressure of the rubber rings on the strip surface, easily creates blade marks and rubber ring marks. Current processes often lack precise design for the arrangement of the upper and lower blades, the size of the upper and lower rubber rings, and the assembly structure. They only mitigate these defects by optimizing the shearing blade parameters or using manual lubrication, failing to eliminate them at their source. For automotive galvanized steel strips with high surface quality requirements, these marks directly lead to product scrap, and the protective effect is unstable, potentially even causing secondary contamination in subsequent processes.

[0004] Secondly, the formation of zinc powder condensation and blade nodules is a serious problem, accelerating blade wear and contaminating the finished product. During shearing, the zinc layer at the edge of the strip is detached due to shear stress, forming zinc powder. Simultaneously, the shearing friction generates a large amount of heat, causing the zinc layer to melt and condense and accumulate on the shear blade edge and surface, gradually evolving into hard nodules. These nodules not only dull the shear blade and cause abnormal shearing clearance, exacerbating burrs and zinc layer peeling at the strip edge, but also continuously wear down the blade edge and surface coating as the blade rotates, significantly shortening blade life. Furthermore, the nodules and detached zinc powder easily fall onto the surface of the running finished strip, forming indentations and zinc powder contamination, severely affecting product quality. Cleaning nodules often requires machine downtime, increasing maintenance costs and the risk of production interruption.

[0005] To address the aforementioned issues, some existing technologies employ conventional lubrication or single air blowing. However, improper selection of the lubricating medium, insufficient cooling effect, and unreasonable air blowing position and direction make it difficult to effectively reduce blade temperature and inhibit zinc layer melting and solidification, potentially even causing zinc powder contamination of the finished product. Other solutions fail to integrate the scraper and lubrication device, resulting in poor synergy and limited effectiveness in removing already adhered zinc powder and initial nodules. Furthermore, most solutions do not focus on optimizing the size and arrangement of the upper and lower blades and the adhesive ring, failing to simultaneously address blade and adhesive ring marks, and lacking a comprehensive control technology encompassing "temperature reduction and melting inhibition, adhesion removal, and nodule prevention." Therefore, the industry urgently needs a new shearing process that integrates precise structural design and multi-dimensional collaborative control. Summary of the Invention

[0006] To address the aforementioned problems, the purpose of this invention is to provide a galvanized steel wire disc shearing method that prevents the disc shear blades from scratching the finished galvanized steel strip and inhibits zinc powder condensation and blade nodule formation. This invention precisely solves the defects of blade marks and adhesive ring marks by optimizing the arrangement of the upper and lower blades, the size of the upper and lower adhesive rings, and the assembly structure. At the same time, high-pressure air is used to blow air at the inlet at a 45° angle to the direction of strip movement. Relying on the advantages of the integrated structure, this invention inhibits zinc powder condensation and nodule formation, avoids zinc powder contamination, extends the service life of the shear blades, and ensures product surface quality and production continuity.

[0007] The technical solution of the present invention is: a method for shearing galvanized steel strip by a disc shear blade to prevent the disc shear blade from scratching the finished galvanized steel strip and to inhibit the agglomeration of zinc powder and the formation of blade nodules, comprising the following steps: S1: Pre-shearing preparation: Apply TiN / TiCN composite ceramic coating to the disc shear blades. Arrange the upper blade of the disc shear outside the lower blade so that it only contacts the strip to be sheared into scrap edges. The inner diameter of the upper rubber ring of the disc shear is fitted with a clearance of 0.02~0.03mm to the shaft diameter of the upper shear blade and is assembled tightly against the upper blade. The outer radius of the upper rubber ring is 3mm smaller than the radius of the upper blade, and the width of the upper rubber ring is the same as the width of the upper blade shear blade. The inner diameter of the lower rubber ring is fitted with a clearance of 0.02~0.03mm to the shaft diameter of the lower shear blade and is assembled tightly against the lower blade. The outer radius of the lower rubber ring is 0.05~0.08mm larger than the radius of the lower blade, and the width of the lower rubber ring is the same as the width of the lower blade shear blade. According to the thickness of the galvanized strip and the weight of the zinc layer, calibrate the shear blade clearance of the disc shear to 8%~10% of the strip thickness, and the overlap to 1 / 3~1 / 2 of the strip thickness. Prepare SMD40 high-volatility cleaning agent as a lubricating and cooling medium. S2: Shearing Operation Process: Nozzles are installed on the upper and lower surfaces of the strip steel, using high-pressure air as the medium, with a pressure control of 0.4~0.6MPa. The blowing direction is at a 45° angle to the strip's movement direction, aimed at the shearing area and blade surface of the strip steel edge. While the disc shear blades are operating, SMD40 high-volatile cleaning agent is supplied to the shear blade engagement point and scraper edge at a drip rate of 1~3 drops / second. The scraper edge radius is R0.1~R0.2mm, and the contact pressure with the shear blade surface is 3~6N. The strip steel tension is controlled at 5~15N / mm². The upper and lower shear blades of the disc shear rotate in opposite directions at different speeds, with the upper shear blade's linear speed 0.5%~1% faster than the strip steel's running speed. The angle between the shear blades and the strip steel's running direction is set to 0.3°~0.5°. S3: Post-shear cleaning process: A dedicated collection device is set up below the high-pressure air purging area at the inlet to collect the zinc powder-containing airflow generated during purging. The zinc powder is screened, dried, and then returned to the zinc pot of the galvanizing line for recycling. The surface of the disc shear blade is wiped with a felt soaked in SMD40 high-volatile cleaning agent. The surface quality of the finished strip is monitored in real time by a machine vision inspection unit. When scratches or signs of zinc powder condensation are detected, the lubricant dripping rate, air blowing pressure, or shear blade gap is automatically adjusted to form a closed-loop control.

[0008] Furthermore, the TiN / TiCN composite ceramic coating has a coating thickness of 3~5μm and a rounded corner of the disc shear blade of R0.05~R0.1mm.

[0009] Furthermore, the disc shear blade is made of Cr12MoV alloy tool steel, which is vacuum quenched and cryogenically treated to prepare a ceramic coating. The coating hardness is ≥2000HV, the coefficient of friction is ≤0.1, the cutting edge accuracy is ≤0.01mm, and the flatness error is ≤0.005mm / m.

[0010] Furthermore, the surface roughness Ra of the upper and lower rubber rings is ≤0.2μm, the upper rubber ring is made of nitrile rubber with a Shore hardness of 80±5HA, and the lower rubber ring is made of fluororubber with a Shore hardness of 80±5HA.

[0011] Furthermore, in the shearing operation, when the strip running speed is ≤15m / s, the shear blade gap is finely adjusted in real time through the eccentric gap adjustment mechanism, with a response time ≤0.1s; when the strip running speed is >15m / s, the gap is pre-judged and adjusted 1~2 stations in advance based on the data from the previous thickness gauge.

[0012] Furthermore, in the post-cutting cleaning process, the contact pressure between the felt and the shear blade surface is controlled at 2~5N, and the evaporation rate of the SMD40 high-volatility cleaning agent at room temperature is ≥1.2g / (m²·min).

[0013] Furthermore, the post-cutting cleaning process is also accompanied by auxiliary air blowing, with an auxiliary air blowing pressure of 0.15~0.25MPa and a blowing direction consistent with the inlet high-pressure air blowing direction.

[0014] Furthermore, the machine vision inspection unit has a resolution of ≥20 million pixels, a detection speed of ≥30 frames / second, and collects parameters of scratches, edge burrs, and zinc powder indentations on the galvanized sheet surface in real time.

[0015] The technical effects of this invention are as follows: 1. By optimizing the arrangement of the upper and lower blades, the size and assembly structure of the upper and lower rubber rings, the lower rubber ring is closely attached to the lower blade, and its outer circle is 0.05-0.08mm larger than the blade. The material support forms a suspended shearing, eliminating the blade marks of the lower blade. The outer side of the upper blade is arranged to only contact the waste edge, and the upper rubber ring is closely attached to the upper blade, with its outer circle 3mm smaller than the blade radius. This precisely avoids the finished strip and prevents the rubber ring from squeezing marks, thus accurately solving the defects of blade marks and rubber ring marks. At the same time, by selecting nitrile / fluororubber materials, treating the surface roughness, and modifying the ceramic coating and rounded corners of the shear blade, the physical structure completely blocks the marks defects. Compared with the prior art, the scratch rate and marks defect rate of the finished strip are reduced from more than 15% to less than 0.5%. 2. This invention constructs a two-tiered synergistic prevention and control system: "Inlet high-pressure 45° directional air blowing to remove zinc powder + integrated structure of scraper and lubrication device + SMD40 cleaning agent cooling to inhibit melting and remove adhesion." This forms a complete chain of nodule prevention and pollution control logic. The inlet high-pressure air blowing is arranged at the inlet, blowing at a 45° angle along the strip movement direction, which can efficiently remove pre-detached and newly formed zinc powder, reducing the basis for zinc powder adhesion. The integrated structure enables the scraper to remove zinc powder and the cleaning agent to lubricate and cool down simultaneously. It not only inhibits zinc layer melting by cooling and prevents adhesion by lubrication, cutting off the source of nodule formation, but also avoids the accumulation of adhering substances into nodules by real-time scraping. The two work together to thoroughly inhibit blade nodule formation from the source to the end. Compared with the existing technology, the nodule rate of zinc powder condensation on the blade is reduced from more than 20% to less than 0.8%. At the same time, the cleaning agent cools down and protects the blade, extending the service life of the shear blade by more than 60%, and reducing the zinc powder contamination rate of the finished strip steel to less than 0.3%. 3. This invention is highly versatile and intelligent, and can be adapted to the shearing of galvanized sheets with different thicknesses of 0.3-2.0mm and different zinc layer weights of 40-275g / m². Through dynamic parameter adjustment and closed-loop control, it does not require frequent process adjustments and can meet the needs of high-speed galvanizing production lines.

[0016] The following will provide further explanation in conjunction with the accompanying drawings. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the disc shear of the present invention.

[0018] Figure 2 This is a schematic diagram showing the size configuration of the rubber ring and blade on the disc shear of the present invention.

[0019] Figure 3 This is a schematic diagram showing the size configuration of the disc-cutting rubber ring and blade of the present invention.

[0020] Figure 4 This is a schematic diagram of the integrated structure of the scraper and lubrication device of the disc shear of the present invention.

[0021] Figure 5 This is a partially enlarged view of the integrated structure of the scraper and lubrication device of the present invention on a disc shear.

[0022] Reference numerals: 1-Upper scraper and lubrication device; 11-Upper felt; 12-Upper scraper; 2-Upper rubber ring and blade structure; 21-Upper blade; 22-Upper rubber ring; 3-Upper air blower; 4-Lower rubber ring and blade structure; 41-Lower blade; 42-Lower rubber ring; 5-Lower air blower; 6-Lower scraper and lubrication device; 61-Lower felt; 62-Lower scraper. Detailed Implementation

[0023] Example 1 A method for shearing galvanized steel strip using a disc shear blade to prevent scratches on finished strip and to inhibit zinc powder agglomeration and blade nodule formation, comprising the following steps: S1: Pre-shearing preparation: Apply TiN / TiCN composite ceramic coating to the disc shear blades. Arrange the upper blade of the disc shear outside the lower blade so that it only contacts the strip to be sheared into scrap edges. The inner diameter of the upper rubber ring of the disc shear is fitted with a clearance of 0.02~0.03mm to the shaft diameter of the upper shear blade and is assembled tightly against the upper blade. The outer radius of the upper rubber ring is 3mm smaller than the radius of the upper blade, and the width of the upper rubber ring is the same as the width of the upper blade shear blade. The inner diameter of the lower rubber ring is fitted with a clearance of 0.02~0.03mm to the shaft diameter of the lower shear blade and is assembled tightly against the lower blade. The outer radius of the lower rubber ring is 0.05~0.08mm larger than the radius of the lower blade, and the width of the lower rubber ring is the same as the width of the lower blade shear blade. According to the thickness of the galvanized strip and the weight of the zinc layer, calibrate the shear blade clearance of the disc shear to 8%~10% of the strip thickness, and the overlap to 1 / 3~1 / 2 of the strip thickness. Prepare SMD40 high-volatility cleaning agent as a lubricating and cooling medium. S2: Shearing Operation Process: Nozzles are installed on the upper and lower surfaces of the strip steel, using high-pressure air as the medium, with a pressure control of 0.4~0.6MPa. The blowing direction is at a 45° angle to the strip's movement direction, aimed at the shearing area and blade surface of the strip steel edge. While the disc shear blades are operating, SMD40 high-volatile cleaning agent is supplied to the shear blade engagement point and scraper edge at a drip rate of 1~3 drops / second. The scraper edge radius is R0.1~R0.2mm, and the contact pressure with the shear blade surface is 3~6N. The strip steel tension is controlled at 5~15N / mm². The upper and lower shear blades of the disc shear rotate in opposite directions at different speeds, with the upper shear blade's linear speed 0.5%~1% faster than the strip steel's running speed. The angle between the shear blades and the strip steel's running direction is set to 0.3°~0.5°. S3: Post-shear cleaning process: A dedicated collection device is set up below the high-pressure air blowing area at the inlet to collect the zinc powder-containing airflow generated during blowing. The zinc powder is screened, dried, and then returned to the zinc pot of the galvanizing line for recycling. The surface of the disc shear blade is elastically wiped with a felt soaked in SMD40 high-volatility cleaning agent. The surface quality of the finished strip is monitored in real time by a machine vision inspection unit. When scratches or signs of zinc powder condensation are detected, the lubricant dripping rate, air blowing pressure, or shear blade gap is automatically adjusted to form a closed-loop control.

[0024] Furthermore, the TiN / TiCN composite ceramic coating has a coating thickness of 3~5μm and a rounded corner of the disc shear blade of R0.05~R0.1mm.

[0025] Furthermore, the disc shear blade is made of Cr12MoV alloy tool steel, which is vacuum quenched and cryogenically treated to prepare a ceramic coating. The coating hardness is ≥2000HV, the coefficient of friction is ≤0.1, the cutting edge accuracy is ≤0.01mm, and the flatness error is ≤0.005mm / m.

[0026] Furthermore, the surface roughness Ra of the upper and lower rubber rings is ≤0.2μm, the upper rubber ring is made of nitrile rubber with a Shore hardness of 80±5HA, and the lower rubber ring is made of fluororubber with a Shore hardness of 80±5HA.

[0027] Furthermore, in the shearing operation, when the strip running speed is ≤15m / s, the shear blade gap is finely adjusted in real time through the eccentric gap adjustment mechanism, with a response time ≤0.1s; when the strip running speed is >15m / s, the gap is pre-judged and adjusted 1~2 stations in advance based on the data from the previous thickness gauge.

[0028] Furthermore, in the post-cutting cleaning process, the contact pressure between the felt and the shear blade surface is controlled at 2~5N, and the evaporation rate of the SMD40 high-volatility cleaning agent at room temperature is ≥1.2g / (m²·min).

[0029] Furthermore, the post-cutting cleaning process is also accompanied by auxiliary air blowing, with an auxiliary air blowing pressure of 0.15~0.25MPa and a blowing direction consistent with the inlet high-pressure air blowing direction.

[0030] Furthermore, the machine vision inspection unit has a resolution of ≥20 million pixels, a detection speed of ≥30 frames / second, and collects parameters of scratches, edge burrs, and zinc powder indentations on the galvanized sheet surface in real time.

[0031] Example 2 like Figures 1-5 As shown, the hot-dip galvanized automotive sheet with a thickness of 1.0 mm and a zinc layer weight of 120 g / m² was cut using the method described in Example 1. The specific steps are as follows: S1: Pre-cutting preparation procedures: Cr12MoV alloy tool steel disc shear blades are selected. After vacuum quenching and deep cryogenic treatment, a TiN / TiCN composite ceramic coating is prepared on the surface of the shear blade. The coating thickness is controlled at 4μm, the coating hardness is ≥2000HV, and the friction coefficient is ≤0.1. The shear blade edge is rounded with a radius of R0.08mm, the edge accuracy is controlled within 0.01mm, and the flatness error is ≤0.005mm / m. The upper blade 21 in the upper rubber ring and blade structure 2 is arranged outside the lower blade 41 in the lower rubber ring and blade structure, ensuring that the upper blade only contacts the strip that is sheared into waste edges. The upper rubber ring 22 is made of nitrile rubber with a Shore hardness of 80HA. Its inner diameter is 0.025mm away from the upper shear blade shaft diameter. It is assembled tightly against the upper blade. Its outer radius is 3mm smaller than the upper blade radius, and its width is the same as the shear blade width of the upper blade. The lower rubber ring 42 is made of fluororubber with a Shore hardness of 80HA. Its inner diameter is 0.025mm away from the lower shear blade shaft diameter. It is assembled tightly against the lower blade. Its outer radius is 0.06mm larger than the lower blade radius, and its width is the same as the shear blade width of the lower blade. The surfaces of the rubber rings are all polished, with a roughness Ra≤0.15μm. Based on the galvanized strip thickness of 1.0 mm and the zinc layer weight of 120 g / m², the shear blade gap is calibrated to 0.1 mm (10% of the strip thickness) using an eccentric adjustment mechanism, and the overlap is 0.45 mm (approximately half the strip thickness). SMD40 high-volatility cleaning agent is prepared as the lubricating and cooling medium. This cleaning agent has an evaporation rate ≥1.2 g / (m²·min) at room temperature, and is residue-free and non-corrosive. S2: Shearing operation procedure: Upper air blower 3 and lower air blower 5 are respectively installed on the upper and lower surfaces of the strip. The high-pressure air blowing mechanism is arranged on the inlet side of the disc shear. High-pressure air is used as the medium, and the pressure is controlled at 0.5MPa. The blowing direction is at a 45° angle to the strip movement direction and is aimed at the shearing area and shear blade surface of the strip edge. The scraper and lubrication device are integrated into one structure. The upper scraper 12 is connected to the lubrication device 1, and the lower scraper 62 is connected to the lubrication device 6. This structure integrates a polytetrafluoroethylene elastic scraper and a special drip lubrication module. The scraper blade has a radius of 0.15mm and a contact pressure of 4.5N with the shear blade surface. When the disc shear blade is working, SMD40 high-volatile cleaning agent is delivered to the shear blade engagement point and the scraper blade edge at a drip rate of 2 drops / second, so as to achieve scraping, lubrication and cooling at the same time. The strip running speed is controlled at 12m / s, the strip tension is 10N / mm², the upper and lower shear blades rotate in opposite directions at different speeds, the linear speed of the upper shear blade is 0.8% faster than the strip running speed, the linear speed of the lower shear blade is the same as the strip running speed, and the angle between the shear blade and the running direction of the strip is set to 0.4°. S3: Post-cutting cleaning process: A dedicated collection device is installed below the high-pressure air purging area at the inlet to collect the zinc powder-containing airflow generated by the purging. The zinc powder blown up is guided into the collection device. The zinc powder scraped off by the scraper is settled by gravity and assisted by air blowing at a pressure of 0.2 MPa in the same direction as the high-pressure purging, and then flows into the collection device. The collected zinc powder is screened, dried and returned to the zinc pot of the galvanizing line for recycling. The upper felt 11 and lower felt 61, which are soaked in SMD40 high-volatile cleaning agent, are used to elastically wipe the surface of the scissor blade. The contact pressure between the felt and the scissor blade surface is controlled at 3N to avoid damaging the ceramic coating. A machine vision inspection unit with a resolution of ≥20 million pixels and an inspection speed of ≥30 frames / second is installed on the shear exit side. It collects parameters of scratches, burrs on the edge and zinc powder indentation on the galvanized sheet surface in real time and establishes a process parameter-quality correlation database. When scratch defects or signs of zinc powder condensation are detected, the lubricant dripping rate, air blowing pressure or shear blade gap is automatically adjusted to form a closed loop control. After the above-mentioned shearing process, the disc shear blades do not scratch the galvanized steel strip, effectively inhibiting the formation of zinc powder condensation and blade nodules, and preventing nodules from damaging the blades. The surface of the finished strip is free of zinc powder contamination and indentation defects, and the edge burr height is ≤0.02mm. After testing, the printing defect rate is reduced to below 0.3%, the zinc powder condensation and blade nodule rate is ≤0.5%, the zinc powder contamination rate of the finished strip is ≤0.2%, the service life of the shear blade is extended by more than 65% compared with the traditional process, the zinc powder recovery rate reaches 96%, and the qualified rate of the finished strip is increased to over 99.8%.

[0032] Example 3 like Figures 1-5 As shown, the electro-galvanized sheet with a thickness of 0.5 mm and a zinc layer weight of 60 g / m² was cut using the method described in Example 1. The specific steps are as follows: S1: Pre-cutting preparation procedures: Cr12MoV alloy tool steel disc shear blades are selected. After vacuum quenching and deep cryogenic treatment, a TiN / TiCN composite ceramic coating is prepared on the surface of the shear blade. The coating thickness is controlled at 3μm, the coating hardness is ≥2000HV, and the friction coefficient is ≤0.1. The shear blade edge is rounded with a radius of R0.05mm, the edge accuracy is controlled within 0.01mm, and the flatness error is ≤0.005mm / m. In the upper rubber ring and blade structure 2, the upper blade 21 is arranged outside the lower blade 41 of the lower rubber ring and blade structure 4, only contacting the waste edge. The upper rubber ring 22 is made of nitrile rubber with a Shore hardness of 78HA. Its inner diameter is 0.02mm away from the upper shear blade shaft diameter and is assembled tightly against the upper blade. Its outer radius is 3mm smaller than the upper blade radius and its width is the same as the shear blade. The lower rubber ring 42 is made of fluororubber with a Shore hardness of 82HA. Its inner diameter is 0.02mm away from the lower shear blade shaft diameter and is assembled tightly against the lower blade. Its outer radius is 0.05mm larger than the lower blade radius and its width is the same as the shear blade. The surface of the rubber ring is polished to Ra≤0.18μm. Based on the galvanized strip thickness of 0.5mm and zinc layer weight of 60g / m², the shear blade gap is calibrated to 0.05mm (10% of the strip thickness) and the overlap is 0.25mm (1 / 2 of the strip thickness) using an eccentric gap adjustment mechanism. SMD40 high-volatility cleaning agent is prepared as a lubricating and cooling medium. S2: Shearing operation procedure: The high-pressure air purging mechanism is arranged on the inlet side of the disc shear, with the pressure controlled at 0.45MPa. The purging direction is at a 45° angle to the strip movement direction, aimed at the shearing area of ​​the strip edge and the shear blade surface. The scraper and lubrication device are integrated into one structure. The scraper blade has a radius of 0.1mm and a contact pressure of 3N with the shear blade surface. When the disc shear blade is working, SMD40 highly volatile cleaning agent is delivered to the shear blade engagement point and the scraper blade edge at a drip rate of 1 drop / second, achieving simultaneous scraping, lubrication, and cooling. The strip running speed is controlled at 8 m / s, and the strip tension is 8 N / mm². The upper shear blade linear speed is 0.5% faster than the strip running speed, while the lower shear blade linear speed is the same as the strip running speed. The angle between the shear blade and the strip running direction is set to 0.3°. S3: Post-cutting cleaning process: Similar to Example 1, a dedicated collection device is installed below the high-pressure air purging area at the inlet to collect the zinc powder-containing airflow generated during purging. The zinc powder is then sieved, dried, and recycled. The upper felt 11 and lower felt 61, soaked in SMD40 highly volatile cleaning agent, are used to elastically wipe the surface of the shear blade, with the felt contact pressure controlled at 2N. The surface quality of the finished strip is monitored in real time by a machine vision inspection unit, forming a closed-loop control. Implementation Results: After the above-described shearing process, the scratch rate of the galvanized steel strip by the disc shear blades is 0%, there is no zinc powder agglomeration or blade nodule formation, and no accelerated blade wear. There is no contamination of the finished product caused by zinc powder or nodule debris. Edge quality meets standards, fully satisfying the high surface cleanliness requirements for galvanized steel sheets used in electronic components. The printing defect rate is reduced to below 0.2%, the zinc powder agglomeration rate is ≤0.3%, the zinc powder contamination rate of the finished steel strip is ≤0.1%, the shear blade lifespan is extended by more than 70% compared to traditional processes, the zinc powder recovery rate reaches 97%, and the shear blade maintenance cycle is extended, resulting in a significant improvement in production efficiency.

[0033] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for shearing galvanized steel strip using a disc shear blade to prevent scratches on the finished strip and to inhibit zinc powder agglomeration and blade nodule formation, characterized in that: Includes the following steps: S1: Pre-shearing preparation: Apply TiN / TiCN composite ceramic coating to the disc shear blades. Arrange the upper blade of the disc shear outside the lower blade so that it only contacts the strip to be sheared into scrap edges. The inner diameter of the upper rubber ring of the disc shear is fitted with a clearance of 0.02~0.03mm to the shaft diameter of the upper shear blade and is assembled tightly against the upper blade. The outer radius of the upper rubber ring is 3mm smaller than the radius of the upper blade, and the width of the upper rubber ring is the same as the width of the upper blade shear blade. The inner diameter of the lower rubber ring is fitted with a clearance of 0.02~0.03mm to the shaft diameter of the lower shear blade and is assembled tightly against the lower blade. The outer radius of the lower rubber ring is 0.05~0.08mm larger than the radius of the lower blade, and the width of the lower rubber ring is the same as the width of the lower blade shear blade. According to the thickness of the galvanized strip and the weight of the zinc layer, calibrate the shear blade clearance of the disc shear to 8%~10% of the strip thickness, and the overlap to 1 / 3~1 / 2 of the strip thickness. Prepare SMD40 high-volatility cleaning agent as a lubricating and cooling medium. S2: Shearing Operation Process: Nozzles are installed on the upper and lower surfaces of the strip steel, using high-pressure air as the medium, with a pressure control of 0.4~0.6MPa. The blowing direction is at a 45° angle to the strip's movement direction, aimed at the shearing area and blade surface of the strip steel edge. While the disc shear blades are operating, SMD40 high-volatile cleaning agent is supplied to the shear blade engagement point and scraper edge at a drip rate of 1~3 drops / second. The scraper edge radius is R0.1~R0.2mm, and the contact pressure with the shear blade surface is 3~6N. The strip steel tension is controlled at 5~15N / mm². The upper and lower shear blades of the disc shear rotate in opposite directions at different speeds, with the upper shear blade's linear speed 0.5%~1% faster than the strip steel's running speed. The angle between the shear blades and the strip steel's running direction is set to 0.3°~0.5°. S3: Post-shear cleaning process: A dedicated collection device is set up below the high-pressure air purging area at the inlet to collect the zinc powder-containing airflow generated during purging. The zinc powder is screened, dried, and then returned to the zinc pot of the galvanizing line for recycling. The surface of the disc shear blade is wiped with a felt soaked in SMD40 high-volatile cleaning agent. The surface quality of the finished strip is monitored in real time by a machine vision inspection unit. When scratches or signs of zinc powder condensation are detected, the lubricant dripping rate, air blowing pressure, or shear blade gap is automatically adjusted to form a closed-loop control.

2. The method for shearing galvanized steel strip using a disc shear blade to prevent scratches on the finished strip and inhibit zinc powder agglomeration and blade nodule formation, as described in claim 1, is characterized in that... The thickness of the TiN / TiCN composite ceramic coating is 3~5μm, and the radius of the disc shear blade is R0.05~R0.1mm.

3. The method for shearing galvanized steel strip using a disc shear blade to prevent scratches on the finished strip and inhibit zinc powder agglomeration and blade nodule formation, as described in claim 1, is characterized in that... The disc shear blade is made of Cr12MoV alloy tool steel, which is vacuum quenched and cryogenically treated to prepare a ceramic coating. The coating hardness is ≥2000HV, the friction coefficient is ≤0.1, the cutting edge accuracy is ≤0.01mm, and the flatness error is ≤0.005mm / m.

4. The method for shearing galvanized steel strip by disc shear blades according to claim 1, characterized in that, The surface roughness Ra of the upper and lower rubber rings is ≤0.2μm. The upper rubber ring is made of nitrile rubber with a Shore hardness of 80±5HA, and the lower rubber ring is made of fluororubber with a Shore hardness of 80±5HA.

5. The method for shearing galvanized steel strip using a disc shear blade to prevent scratches on the finished strip and inhibit zinc powder agglomeration and blade nodule formation, as described in claim 1, is characterized in that... In the shearing process, when the strip running speed is ≤15m / s, the shear blade gap is finely adjusted in real time through the eccentric gap adjustment mechanism, with a response time ≤0.1s; when the strip running speed is >15m / s, the gap is pre-judged and adjusted 1 to 2 stations in advance based on the data from the previous thickness gauge.

6. The method for shearing galvanized steel strip by disc shear blades according to claim 1, characterized in that, In the post-cutting cleaning process, the contact pressure between the felt and the shear blade surface is controlled at 2~5N, and the SMD40 highly volatile cleaning agent has an evaporation rate of ≥1.2g / (m²·min) at room temperature.

7. The method for shearing galvanized steel strip using a disc shear blade to prevent scratches on the finished strip and inhibit zinc powder agglomeration and blade nodule formation, as described in claim 1, is characterized in that... The post-shear cleaning process is also accompanied by auxiliary air blowing, with an auxiliary air blowing pressure of 0.15~0.25MPa and a blowing direction consistent with the inlet high-pressure air blowing direction.

8. The method for shearing galvanized steel strip using a disc shear blade to prevent scratches on the finished strip and inhibit zinc powder agglomeration and blade nodule formation, as described in claim 1, is characterized in that... The machine vision inspection unit has a resolution of ≥20 million pixels and a detection speed of ≥30 frames / second, and collects parameters of scratches, edge burrs and zinc powder indentations on the galvanized sheet surface in real time.

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