A silicon steel sheet surface treatment process and device

Abstract

This invention discloses a silicon steel sheet surface treatment technology, specifically a silicon steel sheet surface treatment process and apparatus. First, the degreased silicon steel sheet undergoes a gradient pickling process consisting of a pre-stage weak acid pickling and a post-stage composite acid pickling. Next, the pickled silicon steel sheet is subjected to ultrasonic water washing. Subsequently, the silicon steel sheet undergoes passivation treatment. Based on this, this invention achieves gradient rust removal and activity enhancement on the silicon steel sheet surface through synergistic treatment of gradient pickling modification and vacuum plasma activation, combined with a silane passivation process after ultrasonic water washing. Simultaneously, a dense underlying adsorption layer is constructed, resulting in significantly enhanced adhesion between the coating and the substrate, a more uniform and dense internal structure of the coating, and effectively preventing coating voids and peeling under high-temperature conditions.

Description

Technical Field

[0001] This invention relates to the field of silicon steel sheet surface treatment technology, specifically to a silicon steel sheet surface treatment process and apparatus. Background Technology

[0002] Silicon steel sheets, as the core material for power equipment such as transformers and motors, directly determine the iron loss, insulation strength, and service life of the equipment through their surface properties. To reduce iron loss and improve insulation performance, surface treatment must be performed during the production of silicon steel sheets to form a uniform, dense, and strongly adherent insulating coating. Currently, the mainstream surface treatment process is mainly chemical coating, which achieves surface modification through steps such as degreasing, pickling, coating with insulating agents, and drying. With the development of new energy power equipment towards high power and miniaturization, higher requirements are placed on the temperature resistance, corrosion resistance, and film density of the silicon steel sheet surface coating.

[0003] Existing silicon steel sheet surface treatment processes suffer from the following core problems: First, it is difficult to simultaneously achieve coating adhesion and density. While traditional pickling processes can remove surface oxide scale, they can lead to irregular uneven structures on the silicon steel sheet surface, making it prone to voids after applying insulating agents. For example, in a motor factory, 30% of the 30Q130 silicon steel sheets treated with existing processes experienced partial coating peeling after six months of operation at 150℃, resulting in a 25% decrease in core insulation resistance. Second, they are environmentally unfriendly and energy-intensive. Traditional processes use strong acid pickling solutions containing large amounts of heavy metals such as chromium and nickel, with wastewater treatment costs accounting for 18% of the total process cost. Furthermore, the drying process often involves a single high-temperature baking step, consuming up to 120 kWh per ton of silicon steel sheet, which does not meet the requirements of green production. Therefore, this invention proposes a silicon steel sheet surface treatment process and apparatus. Summary of the Invention

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A surface treatment process for silicon steel sheets includes the following specific steps: S1, Conveying: When conveying silicon steel sheets to be processed, the thickness of the silicon steel sheets is detected in real time, and the conveying roller speed and clamping force are automatically adjusted according to the thickness data to ensure that the silicon steel sheets are conveyed smoothly and without deformation. At the same time, air blowing is performed to remove dust during the conveying process. S2, Ultrasonic Degreasing: The silicon steel sheet is immersed in the composite degreasing solution and ultrasonically treated, while the oil and impurities in the composite degreasing solution are filtered through circulation. S3, gradient pickling modification: gradient pickling of degreased silicon steel sheets by front-stage weak pickling and rear-stage composite pickling. S4, Ultrasonic water washing and passivation: First, the pickled silicon steel sheet is ultrasonically washed; then, the silicon steel sheet is passivated. S5, Vacuum Plasma Activation: First, the passivated silicon steel sheet is placed in a vacuum environment, then a mixture of argon and oxygen is introduced, and the plasma generator is started for activation treatment. S6, Nano-coating: Based on electrostatic spraying, the spraying material is sprayed onto the surface of the activated silicon steel sheet; S7, Segmented Gradient Curing: The coated silicon steel sheet is cured in three stages; the first stage is the pre-curing zone, which removes volatile solvents from the coating; the second stage is the curing zone, which promotes the cross-linking reaction of the coating; the third stage is the cooling zone, which avoids cracking of the coating due to excessive temperature difference; and nitrogen gas is introduced for protection during the curing process. S8, Inspection and Acceptance: The coating thickness, surface insulation resistance, and surface morphology of the cured silicon steel sheet are inspected. If they are qualified, the processing is completed.

[0005] As a preferred embodiment of the silicon steel sheet surface treatment process described in this invention, in step S1 the conveying roller speed is set to 0.5-1.2 m / min and the clamping force is set to 0.3-0.8 MPa; in step S1 the air pressure during dust removal is set to 0.4-0.5 MPa and the angle between the airflow direction and the conveying direction is set to 45-60°.

[0006] As a preferred embodiment of the silicon steel sheet surface treatment process described in this invention, the composite degreasing solution in S2 is composed of 5% sodium hydroxide, 3% sodium carbonate, 2% surfactant, 1% sodium gluconate, 1.5% sodium citrate and deionized water; the temperature of the composite degreasing solution during ultrasonic treatment in S2 is set to 60-70℃, and the treatment time is set to 5-8 minutes.

[0007] As a preferred embodiment of the silicon steel sheet surface treatment process described in this invention, wherein: the pickling liquid in the front weak pickling zone of S3 is set to 10% dilute sulfuric acid, the temperature is set to 40-45℃, and the pickling time is set to 2-4 min; the pickling liquid in the rear composite pickling zone of S3 is set to 8% dilute sulfuric acid and 2% hydrofluoric acid, the temperature is set to 50-55℃, and the pickling time is set to 1-2 min; and the spray pressure of the pickling liquid during the pickling process in S3 is set to 0.2-0.3 MPa.

[0008] As a preferred embodiment of the silicon steel sheet surface treatment process described in this invention, wherein: the water temperature during ultrasonic water washing in step S4 is set to 30-40℃, the ultrasonic frequency is set to 30-40kHz, and the treatment time is set to 3-4min; the treatment temperature during passivation treatment in step S4 is set to 50-55℃, the time is set to 2-3min, and the passivation liquid is a 5% silane passivation liquid with a pH value of 7.5-8.5.

[0009] As a preferred embodiment of the silicon steel sheet surface treatment process described in this invention, the vacuum degree of the vacuum environment in S5 is set to 5-10 Pa; the volume ratio of argon to oxygen in S5 is set to 3:1, and the gas flow rate is controlled at 20-30 mL / min; the output power of the plasma generator in S5 is adjusted to 80-120 W according to the thickness of the silicon steel sheet, and the processing time is 1-2 min.

[0010] As a preferred embodiment of the silicon steel sheet surface treatment process described in this invention, wherein: the spraying material in S6 is a nano-grade magnesium oxide-alumina-silica composite insulating coating, the mass ratio of magnesium oxide:alumina:silica is set to 5:4:1, the particle size is set to 50-100nm, and the solid content is set to 40%; the spraying voltage in S6 is set to 60kV, the spraying distance is set to 15-20cm, and the coating thickness is set to 5-8μm.

[0011] As a preferred embodiment of the silicon steel sheet surface treatment process described in this invention, the temperature of the first stage in S7 is set to 120-125℃ and the time is set to 3-4 min; the temperature of the second stage in S7 is set to 200-210℃ and the time is set to 5-6 min; and the temperature of the third stage in S7 is set to 60-65℃ and the time is set to 4-5 min.

[0012] In a preferred embodiment of the silicon steel sheet surface treatment process described in this invention, the nitrogen flow rate in step S7 is set to 50-60 mL / min.

[0013] A silicon steel sheet surface treatment device, comprising: The conveying module is used to detect the thickness of the silicon steel sheets in real time during the conveying process, and automatically adjust the speed of the conveying rollers and the clamping force according to the thickness data to ensure that the silicon steel sheets are conveyed smoothly and without deformation. At the same time, it blows air to remove dust during the conveying process. The ultrasonic-assisted degreasing module is used to immerse silicon steel sheets in a composite degreasing solution and perform ultrasonic treatment, while simultaneously circulating and filtering oil and impurities from the composite degreasing solution. The gradient pickling modification module performs gradient pickling on degreased silicon steel sheets by first-stage weak pickling and second-stage composite pickling. The ultrasonic water washing and passivation module is used to perform ultrasonic water washing on the pickled silicon steel sheets; subsequently, the silicon steel sheets are passivated. The vacuum plasma activation module is used to first place the passivated silicon steel sheet in a vacuum environment, then introduce a mixture of argon and oxygen gas, and start the plasma generator for activation treatment. A nano-coating module is used to spray spray material onto the surface of activated silicon steel sheets using electrostatic spraying. The segmented gradient curing module is used to cure coated silicon steel sheets in three stages: the first stage is the pre-curing zone, which removes volatile solvents from the coating; the second stage is the curing zone, which promotes the cross-linking reaction of the coating; and the third stage is the cooling zone, which prevents the coating from cracking due to excessive temperature difference; and nitrogen gas is introduced for protection during the curing process. The receiving module is used to inspect the coating thickness, surface insulation resistance, and surface morphology of the cured silicon steel sheets. If they pass the inspection, the processing is completed.

[0014] Compared with existing technologies: 1. By combining gradient acid pickling modification with vacuum plasma activation and ultrasonic water washing followed by silane passivation, the surface of silicon steel sheet is subjected to gradient rust removal and activity enhancement. At the same time, a dense bottom adsorption layer is constructed, which significantly enhances the bonding force between the coating and the substrate, makes the internal structure of the coating more uniform and dense, and effectively avoids coating voids and peeling under high temperature conditions. 2. By using silane passivation liquid to replace the traditional passivation system containing heavy metals, and combining it with segmented gradient solidification, the amount of heavy metal wastewater generated is reduced. At the same time, the gradient heating and cooling design improves energy utilization efficiency. It has the advantages of reducing the difficulty and cost of process wastewater treatment, significantly reducing overall energy consumption, and conforming to the concept of green production. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall framework of the present invention. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0017] Example 1: This invention provides a surface treatment process for silicon steel sheets. Please refer to [link / reference]. Figure 1 The specific steps are as follows: S1, Conveying: When conveying silicon steel sheets to be processed, the thickness of the silicon steel sheets is detected in real time, and the conveying roller speed (0.5m / min) and clamping force (0.3MPa) are automatically adjusted according to the thickness data to ensure that the silicon steel sheets are conveyed smoothly and without deformation. At the same time, air blowing dust removal is carried out during the conveying process, with the air pressure set at 0.4MPa and the airflow direction at a 45° angle to the conveying direction. S2, Ultrasonic-assisted degreasing: The silicon steel sheet is immersed in a composite degreasing solution (composed of 5% sodium hydroxide, 3% sodium carbonate, 2% surfactant, 1% sodium gluconate, 1.5% sodium citrate and deionized water) and subjected to ultrasonic treatment. The ultrasonic frequency is adaptively adjusted according to the thickness of the silicon steel sheet (40kHz for 0.1-0.3mm thickness, 28kHz for 0.3-0.5mm thickness). The temperature of the degreasing solution is maintained at 60℃, and the treatment time is 5min. At the same time, the oil and impurities in the composite degreasing solution are circulated and filtered, with a filtration accuracy of 5μm. S3, Gradient pickling modification: The degreased silicon steel sheet is subjected to gradient pickling in the first stage of weak pickling and the second stage of composite pickling. The pickling liquid in the first stage of weak pickling is 10% dilute sulfuric acid and the temperature is set to 40℃. The pickling liquid in the second stage of composite pickling is 8% dilute sulfuric acid and 2% hydrofluoric acid and the temperature is set to 50℃. First, the silicon steel sheet is pickled in the first stage of weak pickling for 2 minutes, and then the silicon steel sheet is pickled in the second stage of composite pickling for 1 minute. The spray pressure of the pickling liquid during the pickling process is set to 0.2MPa to ensure uniform removal of the surface oxide scale and avoid excessive corrosion. S4, Ultrasonic Water Washing and Passivation: First, the pickled silicon steel sheet is ultrasonically washed with water at a temperature of 30℃, an ultrasonic frequency of 30kHz, and a treatment time of 3min to remove residual acid from the surface. Then, the silicon steel sheet is passivated with a 5% silane passivation solution (pH 7.5) at a temperature of 50℃ for 2min to form a dense silane adsorption layer on the surface of the silicon steel sheet, thereby improving the adhesion of subsequent coatings. S5, Vacuum Plasma Activation: First, the passivated silicon steel sheet is placed in a vacuum environment with a vacuum degree of 5 Pa. Then, a mixture of argon and oxygen (volume ratio 3:1) is introduced, with the gas flow rate controlled at 20 mL / min. The plasma generator is then started for activation treatment, with its output power adjusted to 80 W according to the thickness of the silicon steel sheet. The treatment time is 1 min, so as to increase the surface roughness and the number of active groups by bombarding the surface of the silicon steel sheet with plasma. S6, Nano-coating application: Electrostatic spraying is used to apply a coating material to the surface of the activated silicon steel sheet; the coating material is a nano-grade magnesium oxide-alumina-silica composite insulating coating (the mass ratio of magnesium oxide:alumina:silica is set to 5:4:1, the particle size is set to 50nm, and the solid content is set to 40%), the spraying voltage is set to 60kV, the spraying distance is set to 15cm, and the spraying flow rate can be adjusted according to the thickness of the silicon steel sheet (8-10mL / min for 0.1-0.3mm thickness, 12-15mL / min for 0.3-0.5mm thickness) to ensure that the coating thickness is uniformly controlled at 5μm; S7, Segmented Gradient Curing: The coated silicon steel sheet undergoes three-stage curing. The first stage is the pre-curing zone (temperature set at 120℃, time set at 3min) to remove volatile solvents from the coating; the second stage is the curing zone (temperature set at 200℃, time set at 5min) to promote the cross-linking reaction of the coating; the third stage is the cooling zone (temperature reduced to 60℃, time set at 4min) to prevent the coating from cracking due to excessive temperature difference; nitrogen gas is introduced for protection during the curing process, with a nitrogen flow rate of 50mL / min. S8, Inspection and Acceptance: The coating thickness, surface insulation resistance, and surface morphology of the cured silicon steel sheet are inspected. If they are qualified, the processing is completed.

[0018] A silicon steel sheet surface treatment device, comprising: The conveying module is used to detect the thickness of the silicon steel sheets in real time during the conveying process, and automatically adjust the speed of the conveying rollers and the clamping force according to the thickness data to ensure that the silicon steel sheets are conveyed smoothly and without deformation. At the same time, it blows air to remove dust during the conveying process. The ultrasonic-assisted degreasing module is used to immerse silicon steel sheets in a composite degreasing solution and perform ultrasonic treatment, while simultaneously circulating and filtering oil and impurities from the composite degreasing solution. The gradient pickling modification module performs gradient pickling on degreased silicon steel sheets by first-stage weak pickling and second-stage composite pickling. The ultrasonic water washing and passivation module is used to perform ultrasonic water washing on the pickled silicon steel sheets; subsequently, the silicon steel sheets are passivated. The vacuum plasma activation module is used to first place the passivated silicon steel sheet in a vacuum environment, then introduce a mixture of argon and oxygen gas, and start the plasma generator for activation treatment. A nano-coating module is used to spray spray material onto the surface of activated silicon steel sheets using electrostatic spraying. The segmented gradient curing module is used to cure coated silicon steel sheets in three stages: the first stage is the pre-curing zone, which removes volatile solvents from the coating; the second stage is the curing zone, which promotes the cross-linking reaction of the coating; and the third stage is the cooling zone, which prevents the coating from cracking due to excessive temperature difference; and nitrogen gas is introduced for protection during the curing process. The receiving module is used to inspect the coating thickness, surface insulation resistance, and surface morphology of the cured silicon steel sheets. If they pass the inspection, the processing is completed.

[0019] Example 2: This invention provides a surface treatment process for silicon steel sheets. Please refer to [link / reference]. Figure 1 The specific steps are as follows: S1, Conveying: When conveying the silicon steel sheets to be processed, the thickness of the silicon steel sheets is detected in real time, and the conveying roller speed (0.8m / min) and clamping force (0.55MPa) are automatically adjusted according to the thickness data to ensure that the silicon steel sheets are conveyed smoothly and without deformation. At the same time, air blowing dust removal is carried out during the conveying process, with the air pressure set at 0.45MPa and the airflow direction at a 50° angle to the conveying direction. S2, Ultrasonic Degreasing: The silicon steel sheet is immersed in a composite degreasing solution (composed of 5% sodium hydroxide, 3% sodium carbonate, 2% surfactant, 1% sodium gluconate, 1.5% sodium citrate and deionized water) and subjected to ultrasonic treatment. The ultrasonic frequency is adaptively adjusted according to the thickness of the silicon steel sheet (40kHz for 0.1-0.3mm thickness, 28kHz for 0.3-0.5mm thickness). The temperature of the degreasing solution is maintained at 65℃, and the treatment time is 6.5min. At the same time, the oil and impurities in the composite degreasing solution are circulated and filtered, with a filtration accuracy of 5μm. S3, Gradient pickling modification: The degreased silicon steel sheet is subjected to gradient pickling in the first stage of weak pickling and the second stage of composite pickling. The pickling liquid in the first stage of weak pickling is 10% dilute sulfuric acid and the temperature is set to 42.5℃. The pickling liquid in the second stage of composite pickling is 8% dilute sulfuric acid and 2% hydrofluoric acid and the temperature is set to 52.5℃. First, the silicon steel sheet is pickled in the first stage of weak pickling for 3 minutes, and then the silicon steel sheet is pickled in the second stage of composite pickling for 1.5 minutes. The spray pressure of the pickling liquid during the pickling process is set to 0.25MPa to ensure uniform removal of the surface oxide scale and avoid excessive corrosion. S4, Ultrasonic Water Washing and Passivation: First, the pickled silicon steel sheet is ultrasonically washed at a water temperature of 35℃, an ultrasonic frequency of 35kHz, and a treatment time of 3.5min to remove residual acid from the surface. Then, the silicon steel sheet is passivated with a 5% silane passivation solution (pH 8.0) at a treatment temperature of 52.5℃ for 2.5min to form a dense silane adsorption layer on the surface of the silicon steel sheet, thereby improving the adhesion of subsequent coatings. S5, Vacuum Plasma Activation: First, the passivated silicon steel sheet is placed in a vacuum environment with a vacuum degree of 7.5 Pa. Then, a mixture of argon and oxygen (volume ratio 3:1) is introduced, with the gas flow rate controlled at 25 mL / min. The plasma generator is then started for activation treatment, with its output power adjusted to 100 W according to the thickness of the silicon steel sheet. The treatment time is 1.5 min, in order to increase the surface roughness and the number of active groups by bombarding the surface of the silicon steel sheet with plasma. S6, Nano-coating application: Electrostatic spraying is used to apply a coating material to the surface of the activated silicon steel sheet; the coating material is a nano-grade magnesium oxide-alumina-silica composite insulating coating (the mass ratio of magnesium oxide:alumina:silica is set to 5:4:1, the particle size is set to 75nm, and the solid content is set to 40%), the spraying voltage is set to 60kV, the spraying distance is set to 17.5cm, and the spraying flow rate can be adjusted according to the thickness of the silicon steel sheet (8-10mL / min for 0.1-0.3mm thickness, 12-15mL / min for 0.3-0.5mm thickness) to ensure that the coating thickness is uniformly controlled at 6.5μm; S7, Segmented Gradient Curing: The coated silicon steel sheet undergoes three-stage curing. The first stage is the pre-curing zone (temperature set at 122.5℃, time set at 3.5min), which removes volatile solvents from the coating. The second stage is the curing zone (temperature set at 205℃, time set at 5.5min), which promotes the cross-linking reaction of the coating. The third stage is the cooling zone (temperature reduced to 62.5℃, time set at 4.5min), which prevents the coating from cracking due to excessive temperature difference. Nitrogen gas is introduced for protection during the curing process, with a nitrogen flow rate of 55mL / min. S8, Inspection and Acceptance: The coating thickness, surface insulation resistance, and surface morphology of the cured silicon steel sheet are inspected. If they are qualified, the processing is completed.

[0020] A silicon steel sheet surface treatment device, comprising: The conveying module is used to detect the thickness of the silicon steel sheets in real time during the conveying process, and automatically adjust the speed of the conveying rollers and the clamping force according to the thickness data to ensure that the silicon steel sheets are conveyed smoothly and without deformation. At the same time, it blows air to remove dust during the conveying process. The ultrasonic-assisted degreasing module is used to immerse silicon steel sheets in a composite degreasing solution and perform ultrasonic treatment, while simultaneously circulating and filtering oil and impurities from the composite degreasing solution. The gradient pickling modification module performs gradient pickling on degreased silicon steel sheets by first-stage weak pickling and second-stage composite pickling. The ultrasonic water washing and passivation module is used to perform ultrasonic water washing on the pickled silicon steel sheets; subsequently, the silicon steel sheets are passivated. The vacuum plasma activation module is used to first place the passivated silicon steel sheet in a vacuum environment, then introduce a mixture of argon and oxygen gas, and start the plasma generator for activation treatment. A nano-coating module is used to spray spray material onto the surface of activated silicon steel sheets using electrostatic spraying. The segmented gradient curing module is used to cure coated silicon steel sheets in three stages: the first stage is the pre-curing zone, which removes volatile solvents from the coating; the second stage is the curing zone, which promotes the cross-linking reaction of the coating; and the third stage is the cooling zone, which prevents the coating from cracking due to excessive temperature difference; and nitrogen gas is introduced for protection during the curing process. The receiving module is used to inspect the coating thickness, surface insulation resistance, and surface morphology of the cured silicon steel sheets. If they pass the inspection, the processing is completed.

[0021] Example 3: This invention provides a surface treatment process for silicon steel sheets. Please refer to [link / reference]. Figure 1 The specific steps are as follows: S1, Conveying: When conveying silicon steel sheets to be processed, the thickness of the silicon steel sheets is detected in real time, and the conveying roller speed (1.2m / min) and clamping force (0.8MPa) are automatically adjusted according to the thickness data to ensure that the silicon steel sheets are conveyed smoothly and without deformation. At the same time, air blowing dust removal is carried out during the conveying process, with the air pressure set at 0.5MPa and the airflow direction at a 60° angle to the conveying direction. S2, Ultrasonic Degreasing: The silicon steel sheet is immersed in a composite degreasing solution (composed of 5% sodium hydroxide, 3% sodium carbonate, 2% surfactant, 1% sodium gluconate, 1.5% sodium citrate and deionized water) and subjected to ultrasonic treatment. The ultrasonic frequency is adaptively adjusted according to the thickness of the silicon steel sheet (40kHz for 0.1-0.3mm thickness, 28kHz for 0.3-0.5mm thickness). The temperature of the degreasing solution is maintained at 70℃, and the treatment time is 8 minutes. At the same time, the oil and impurities in the composite degreasing solution are circulated and filtered, with a filtration accuracy of 5μm. S3, Gradient pickling modification: The degreased silicon steel sheet is subjected to gradient pickling in the first stage of weak pickling and the second stage of composite pickling. The pickling liquid in the first stage of weak pickling is 10% dilute sulfuric acid and the temperature is set to 45℃. The pickling liquid in the second stage of composite pickling is 8% dilute sulfuric acid and 2% hydrofluoric acid and the temperature is set to 55℃. First, the silicon steel sheet is pickled in the first stage of weak pickling for 4 minutes, and then the silicon steel sheet is pickled in the second stage of composite pickling for 2 minutes. The spray pressure of the pickling liquid during the pickling process is set to 0.3MPa to ensure uniform removal of the oxide scale on the surface and avoid excessive corrosion. S4, Ultrasonic Water Washing and Passivation: First, the pickled silicon steel sheet is ultrasonically washed with water at a temperature of 40℃, an ultrasonic frequency of 40kHz, and a treatment time of 4min to remove residual acid from the surface. Then, the silicon steel sheet is passivated with 5% silane passivation solution (pH 8.5) at a temperature of 55℃ for 3min to form a dense silane adsorption layer on the surface of the silicon steel sheet, thereby improving the adhesion of subsequent coatings. S5, Vacuum Plasma Activation: First, the passivated silicon steel sheet is placed in a vacuum environment with a vacuum degree of 10 Pa. Then, a mixture of argon and oxygen (volume ratio 3:1) is introduced, with the gas flow rate controlled at 30 mL / min. The plasma generator is then started for activation treatment, with its output power adjusted to 120 W according to the thickness of the silicon steel sheet. The treatment time is 2 min, in order to increase the surface roughness and the number of active groups by bombarding the surface of the silicon steel sheet with plasma. S6, Nano-coating application: Electrostatic spraying is used to apply a coating material to the surface of the activated silicon steel sheet; the coating material is a nano-grade magnesium oxide-alumina-silica composite insulating coating (the mass ratio of magnesium oxide:alumina:silica is set to 5:4:1, the particle size is set to 100nm, and the solid content is set to 40%), the spraying voltage is set to 60kV, the spraying distance is set to 20cm, and the spraying flow rate can be adjusted according to the thickness of the silicon steel sheet (8-10mL / min for 0.1-0.3mm thickness, 12-15mL / min for 0.3-0.5mm thickness) to ensure that the coating thickness is uniformly controlled at 8μm; S7, Segmented Gradient Curing: The coated silicon steel sheet undergoes three-stage curing. The first stage is the pre-curing zone (temperature set at 125℃, time set at 4min) to remove volatile solvents from the coating. The second stage is the curing zone (temperature set at 210℃, time set at 6min) to promote the cross-linking reaction of the coating. The third stage is the cooling zone (temperature reduced to 65℃, time set at 5min) to prevent the coating from cracking due to excessive temperature difference. Nitrogen gas is introduced for protection during the curing process, with a nitrogen flow rate of 60mL / min. S8, Inspection and Acceptance: The coating thickness, surface insulation resistance, and surface morphology of the cured silicon steel sheet are inspected. If they are qualified, the processing is completed.

[0022] A silicon steel sheet surface treatment device, comprising: The conveying module is used to detect the thickness of the silicon steel sheets in real time during the conveying process, and automatically adjust the speed of the conveying rollers and the clamping force according to the thickness data to ensure that the silicon steel sheets are conveyed smoothly and without deformation. At the same time, it blows air to remove dust during the conveying process. The ultrasonic-assisted degreasing module is used to immerse silicon steel sheets in a composite degreasing solution and perform ultrasonic treatment, while simultaneously circulating and filtering oil and impurities from the composite degreasing solution. The gradient pickling modification module performs gradient pickling on degreased silicon steel sheets by first-stage weak pickling and second-stage composite pickling. The ultrasonic water washing and passivation module is used to perform ultrasonic water washing on the pickled silicon steel sheets; subsequently, the silicon steel sheets are passivated. The vacuum plasma activation module is used to first place the passivated silicon steel sheet in a vacuum environment, then introduce a mixture of argon and oxygen gas, and start the plasma generator for activation treatment. A nano-coating module is used to spray spray material onto the surface of activated silicon steel sheets using electrostatic spraying. The segmented gradient curing module is used to cure coated silicon steel sheets in three stages: the first stage is the pre-curing zone, which removes volatile solvents from the coating; the second stage is the curing zone, which promotes the cross-linking reaction of the coating; and the third stage is the cooling zone, which prevents the coating from cracking due to excessive temperature difference; and nitrogen gas is introduced for protection during the curing process. The receiving module is used to inspect the coating thickness, surface insulation resistance, and surface morphology of the cured silicon steel sheets. If they pass the inspection, the processing is completed.

[0023] By comparing the surface treatment processes of silicon steel sheets performed in Examples 1-3 above, the following data were obtained: As can be seen from the table above, the silicon steel sheet surface treatment processes carried out in Examples 1-3 all showed good performance in terms of surface insulation resistance and coating density. After use, Example 2 showed the best results.

[0024] Although the present invention has been described above with reference to embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, as long as there is no structural conflict, the features in the disclosed embodiments can be combined with each other in any manner. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A surface treatment process for silicon steel sheets, characterized in that, The specific steps are as follows: S1, Conveying: When conveying silicon steel sheets to be processed, the thickness of the silicon steel sheets is detected in real time, and the conveying roller speed and clamping force are automatically adjusted according to the thickness data to ensure that the silicon steel sheets are conveyed smoothly and without deformation. At the same time, air blowing is performed to remove dust during the conveying process. S2, Ultrasonic Degreasing: The silicon steel sheet is immersed in the composite degreasing solution and ultrasonically treated, while the oil and impurities in the composite degreasing solution are filtered through circulation. S3, gradient pickling modification: gradient pickling of degreased silicon steel sheets by front-stage weak pickling and rear-stage composite pickling. S4, Ultrasonic water washing and passivation: First, the pickled silicon steel sheet is ultrasonically washed; then, the silicon steel sheet is passivated. S5, Vacuum Plasma Activation: First, the passivated silicon steel sheet is placed in a vacuum environment, then a mixture of argon and oxygen is introduced, and the plasma generator is started for activation treatment. S6, Nano-coating: Based on electrostatic spraying, the spraying material is sprayed onto the surface of the activated silicon steel sheet; S7, Segmented Gradient Curing: The coated silicon steel sheet is cured in three stages; The first section is the pre-curing zone, which removes volatile solvents from the coating; the second section is the curing zone, which promotes the cross-linking reaction of the coating. The third section is a cooling zone to prevent the coating from cracking due to excessive temperature differences. Nitrogen gas is introduced for protection during the curing process; S8, Inspection and Acceptance: The coating thickness, surface insulation resistance, and surface morphology of the cured silicon steel sheet are inspected. If they are qualified, the processing is completed.

2. The surface treatment process for silicon steel sheets according to claim 1, characterized in that, In S1, the conveying roller speed is set to 0.5-1.2 m / min, and the clamping force is set to 0.3-0.8 MPa; in S1, the air pressure during dust removal is set to 0.4-0.5 MPa, and the angle between the airflow direction and the conveying direction is set to 45-60°.

3. The surface treatment process for silicon steel sheets according to claim 1, characterized in that, The composite degreasing solution in S2 is composed of 5% sodium hydroxide, 3% sodium carbonate, 2% surfactant, 1% sodium gluconate, 1.5% sodium citrate and deionized water; the temperature of the composite degreasing solution during ultrasonic treatment in S2 is set to 60-70℃, and the treatment time is set to 5-8 minutes.

4. The surface treatment process for silicon steel sheets according to claim 1, characterized in that, The pickling liquid in the front weak pickling zone of S3 is set to 10% dilute sulfuric acid, the temperature is set to 40-45℃, and the pickling time is set to 2-4 min; the pickling liquid in the rear composite pickling zone of S3 is set to 8% dilute sulfuric acid and 2% hydrofluoric acid, the temperature is set to 50-55℃, and the pickling time is set to 1-2 min; the spray pressure of the pickling liquid during the pickling process in S3 is set to 0.2-0.3 MPa.

5. The surface treatment process for silicon steel sheets according to claim 1, characterized in that, In step S4, the water temperature for ultrasonic water washing is set to 30-40℃, the ultrasonic frequency is set to 30-40kHz, and the processing time is set to 3-4min. In step S4, the passivation treatment temperature is set to 50-55℃, the time is set to 2-3min, and the passivation liquid is a 5% silane passivation solution with a pH value of 7.5-8.

5.

6. The surface treatment process for silicon steel sheets according to claim 1, characterized in that, The vacuum level of the vacuum environment in S5 is set to 5-10 Pa; the volume ratio of argon to oxygen in S5 is set to 3:1, and the gas flow rate is controlled at 20-30 mL / min; the output power of the plasma generator in S5 is adjusted to 80-120 W according to the thickness of the silicon steel sheet, and the processing time is 1-2 min.

7. The surface treatment process for silicon steel sheets according to claim 1, characterized in that, The spraying material in S6 is a nano-grade magnesium oxide-alumina-silica composite insulating coating, with a magnesium oxide:alumina:silica mass ratio of 5:4:1, a particle size of 50-100nm, and a solid content of 40%. The spraying voltage in S6 is 60kV, the spraying distance is 15-20cm, and the coating thickness is 5-8μm.

8. The surface treatment process for silicon steel sheets according to claim 1, characterized in that, The temperature of the first segment in S7 is set to 120-125℃ and the time is set to 3-4 min; the temperature of the second segment in S7 is set to 200-210℃ and the time is set to 5-6 min; the temperature of the third segment in S7 is set to 60-65℃ and the time is set to 4-5 min.

9. The surface treatment process for silicon steel sheets according to claim 1, characterized in that, The nitrogen flow rate in S7 is set to 50-60 mL / min.

10. A surface treatment device for silicon steel sheets, characterized in that, include: The conveying module is used to detect the thickness of the silicon steel sheets in real time during the conveying process, and automatically adjust the speed of the conveying rollers and the clamping force according to the thickness data to ensure that the silicon steel sheets are conveyed smoothly and without deformation. At the same time, it blows air to remove dust during the conveying process. The ultrasonic-assisted degreasing module is used to immerse silicon steel sheets in a composite degreasing solution and perform ultrasonic treatment, while simultaneously circulating and filtering oil and impurities from the composite degreasing solution. The gradient pickling modification module performs gradient pickling on degreased silicon steel sheets by first-stage weak pickling and second-stage composite pickling. The ultrasonic water washing and passivation module is used to perform ultrasonic water washing on the pickled silicon steel sheets; subsequently, the silicon steel sheets are passivated. The vacuum plasma activation module is used to first place the passivated silicon steel sheet in a vacuum environment, then introduce a mixture of argon and oxygen gas, and start the plasma generator for activation treatment. A nano-coating module is used to spray spray material onto the surface of activated silicon steel sheets using electrostatic spraying. The segmented gradient curing module is used to cure the coated silicon steel sheet in three stages. The first section is the pre-curing zone, which removes volatile solvents from the coating; the second section is the curing zone, which promotes the cross-linking reaction of the coating. The third section is a cooling zone to prevent the coating from cracking due to excessive temperature differences. Nitrogen gas is introduced for protection during the curing process; The receiving module is used to inspect the coating thickness, surface insulation resistance, and surface morphology of the cured silicon steel sheets. If they pass the inspection, the processing is completed.

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