A corrosion protection process for a wavy guardrail

Abstract

The present application relates to the field of corrugated guardrail processing technology, and more particularly to a corrugated guardrail anticorrosion processing technology, which has the advantages of high coating efficiency and good anticorrosion effect, and comprises the following steps: 1) performing surface cleaning treatment on the corrugated guardrail; 2) performing polishing treatment on the surface of the dried guardrail; 3) preparing a primer; 4) applying the prepared primer to the surface of the pretreated guardrail by brushing; 5) drying the guardrail coated with the primer; 6) preparing an intermediate paint; 7) applying the intermediate paint to the surface of the cured primer by spraying; 8) drying the guardrail coated with the intermediate paint; 9) preparing a top paint; 10) applying the top paint to the surface of the cured intermediate paint by spraying; 11) drying the guardrail coated with the top paint; 12) performing inspection on the surface of the cured top paint; and 13) applying a hydrophobic coating with a thickness of 5-10 microns to the surface of the guardrail.

Description

Technical Field

[0001] This invention relates to the field of corrugated guardrail processing technology, and more particularly to a corrugated guardrail anti-corrosion processing technology. Background Technology

[0002] Corrugated beam guardrails, also known as "wave-beam guardrails," are a major form of rigid guardrails. They are continuous structures made of corrugated steel guardrail panels spliced ​​together and supported by posts. Each panel consists of two corrugated steel guardrail panels and two posts fixedly clamped between them. As an important traffic safety facility, corrugated beam guardrails are widely used along highways, bridges, and other roads. Their main function is to prevent vehicles from running off the road due to accidents, ensuring driving safety. Because the corrugated beam guardrail material is exposed to the elements for extended periods, it is subject to corrosion from various factors such as ultraviolet radiation, rainwater erosion, acid and alkali corrosion, and atmospheric oxygen and water vapor. This leads to rust and oxidation on the guardrail surface, affecting not only its appearance but also its strength and lifespan, increasing safety hazards. To achieve safety and reliability, the corrugated beam guardrail material must possess high hardness and corrosion resistance; therefore, during processing, the anti-corrosion layer of the corrugated beam guardrail material must have good corrosion resistance and be resistant to peeling.

[0003] Currently, the common method is to treat the guardrails with anti-corrosion treatments, such as painting. However, existing anti-corrosion processes have some problems, such as insufficient surface treatment, resulting in poor adhesion between the paint and the guardrail surface, making it easy for the paint to peel off; the painting process is not refined enough, and the bonding between the paint layers is not tight, affecting the overall anti-corrosion effect; and there is a lack of effective defect detection and repair methods, making it difficult to ensure the consistency and stability of the coating quality. Summary of the Invention

[0004] Therefore, in view of the above problems, the present invention provides a corrugated guardrail anti-corrosion treatment process with high coating efficiency and good anti-corrosion effect.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A corrosion protection process for corrugated guardrails includes the following steps:

[0007] 1) Clean the surface of the corrugated guardrail. First, use a high-pressure water gun at a pressure of not less than 15MPa to rinse the surface of the guardrail to remove dust, dirt and loose impurities. Then, use acetone to wipe the surface of the guardrail to further remove oil stains and stains that are difficult to rinse off with water. Finally, place the guardrail in a drying equipment at a temperature of 50-70℃ for 15-30 minutes to dry the surface of the guardrail completely.

[0008] 2) Grind the dried guardrail surface using a 120-220 mesh grinding wheel to remove rust, scale and burrs, so that the surface roughness reaches Ra3.2-Ra6.3μm.

[0009] 3) Prepare the primer. The primer consists of epoxy resin, curing agent, anti-rust pigment, and organic solvent. The epoxy resin accounts for 40-60% of the total mass of the primer, the curing agent accounts for 15-25% of the total mass of the epoxy resin, the anti-rust pigment accounts for 10-20% of the total mass of the primer, and the organic solvent accounts for 10-30% of the total mass of the primer. After mixing the components in the specified proportions, stir at a stirring speed of 300-500 r / min for 20-40 minutes to ensure thorough and uniform mixing.

[0010] 4) Apply the prepared primer to the pretreated guardrail surface by brushing. Use a suitable brush to ensure that the primer evenly covers the guardrail surface. The thickness of the primer coating should be controlled between 20 and 40 μm.

[0011] The brushing method includes the following steps:

[0012] 41) Divide the surface of the guardrail into multiple rectangular areas, each no larger than 30cm x 30cm, and paint each area in order from left to right and from top to bottom;

[0013] 42) In each area, first apply a coat evenly in the horizontal direction. After the primer is surface dry, apply a second coat in the vertical direction.

[0014] 43) Use a non-contact laser thickness gauge to dynamically detect the coating thickness. When the detected value exceeds the range of 20-40 μm, immediately adjust it to the target thickness range by recoating or polishing.

[0015] 5) Place the guardrail with the primer applied in an environment with a temperature of 20-30℃ and a relative humidity of 50-70% to air dry for 1-2 hours, and then put it in an oven and bake at a temperature of 80-100℃ for 30-60 minutes to allow the primer to fully cure.

[0016] 6) Prepare the intermediate paint, which consists of polyurethane resin, filler and organic solvent. The polyurethane resin accounts for 50-70% of the total mass of the intermediate paint, the filler accounts for 20-30% of the total mass of the intermediate paint, and the organic solvent accounts for 10-20% of the total mass of the intermediate paint. After mixing the components in proportion, stir for 30-50 minutes at a stirring speed of 400-600 r / min to ensure that they are fully dispersed and uniform.

[0017] 7) Apply intermediate paint to the cured primer surface by spraying. Control the spray gun pressure at 0.5-0.7MPa and the spraying distance at 25-35cm to ensure that the intermediate paint evenly covers the primer surface. The thickness of the intermediate paint coating should be controlled at 40-60μm.

[0018] 8) Place the guardrail with the intermediate paint applied in an environment with a temperature of 20-30℃ and a relative humidity of 50-70% to air dry for 2-3 hours, and then put it in an oven and bake at a temperature of 100-120℃ for 60-90 minutes to allow the intermediate paint to fully cure.

[0019] 9) Prepare the topcoat, which consists of fluorocarbon resin, pigment and organic solvent, wherein the fluorocarbon resin accounts for 60-80% of the total mass of the topcoat, the pigment accounts for 10-20% of the total mass of the topcoat, and the organic solvent accounts for 10-20% of the total mass of the topcoat; after mixing the components in proportion, stir for 40-60 minutes at a stirring speed of 500-700 r / min to ensure that they are fully mixed and uniform.

[0020] 10) Apply the topcoat to the cured intermediate paint surface by spraying. Control the spray gun pressure at 0.6-0.8 MPa and the spraying distance at 30-40 cm to ensure that the topcoat evenly covers the intermediate paint surface. Control the topcoat coating thickness at 30-50 μm.

[0021] 11) Place the painted guardrail in an environment with a temperature of 20-30℃ and a relative humidity of 50-70% to air dry for 3-4 hours, and then put it in an oven and bake at a temperature of 120-140℃ for 90-120 minutes to allow the paint to fully cure.

[0022] 12) Inspect the cured topcoat surface for defects such as drips, bubbles, and pinholes. If defects are found, lightly sand the defective areas with sandpaper and then reapply the corresponding paint layer for repair.

[0023] The inspection method for defects such as sagging, blistering, and pinholes includes the following steps:

[0024] 121) Install multiple high-definition industrial cameras with a resolution of no less than 5 million pixels above the inspection area to ensure that the field of view of the high-definition industrial cameras can fully cover the surface of the corrugated guardrail without obstruction or blind spots, and there should be a certain overlap between the fields of view of adjacent high-definition industrial cameras to ensure the integrity of the inspection. At the same time, the light intensity of the inspection area should be no less than 500 lux to ensure that the light intensity is uniform and stable.

[0025] 122) Connect the data cable between the high-definition industrial camera and the central control unit, ensuring a secure connection and stable signal transmission, and initialize the image processing system in the central control unit and configure the image storage path, format, and resolution;

[0026] 123) The image processing system is calibrated by taking pictures and processing standard images using a wave guardrail with a known defect-free paint surface as a standard sample.

[0027] 124) Start the image acquisition module in the central control unit to control the high-definition industrial camera to continuously capture images of the surface of the wave guardrail paint at a frame rate of 10-20 frames / second to form inspection images;

[0028] 125) Inspection image data captured by high-definition industrial cameras are transmitted to the central control unit in real time via data cable or wireless communication module. The central control unit stores the received inspection images according to the set storage path and format for subsequent query and analysis. At the same time, the captured inspection images are displayed on the screen in real time for operators to observe initially.

[0029] 126) The intelligent image processing system performs noise reduction processing on the acquired inspection images. It uses a median filtering algorithm to remove noise interference from the images and then uses a histogram equalization method to enhance the contrast of the images, making the defect features of the paint surface more obvious, thus forming a preprocessed image.

[0030] 127) The image processing system extracts the standard image and the preprocessed image for comparison and identifies defects:

[0031] a. By extracting the edge information of the paint surface in the preprocessed image, and by analyzing the changes in the curvature and direction of the edges, when a local edge is found to be significantly bent downward and the local edge curvature threshold exceeds 0.5 rad / mm, it is determined to be a sagging defect.

[0032] b. Calculate the texture feature parameters of the entropy of the gray-level co-occurrence matrix of local areas in the preprocessed image using a texture analysis algorithm. When the entropy value is greater than 3.5, it is outside the normal range and is judged as a bubbling defect.

[0033] c. By setting a threshold of less than 50 grayscale values ​​through a threshold segmentation algorithm, pinholes are separated from the background. Then, the area and shape parameters of the holes are calculated. When the area of ​​the hole is greater than the set value of 0.01 mm² and the roundness is greater than 0.8, it is judged as a pinhole defect.

[0034] 128) Once the image processing system identifies a defect, it immediately sends a signal to the central control unit. The central control unit triggers the prompting device, which displays the location, type, and severity of the defect on the screen. At the same time, the audible and visual alarm sounds and flashes lights to alert the operator.

[0035] 13) Apply a hydrophobic coating with a thickness of 5-10 μm to the surface of the guardrail. The hydrophobic coating is composed of silicone resin and hydrophobic agent, wherein the silicone resin accounts for 80-90% of the total mass of the hydrophobic coating and the hydrophobic agent accounts for 10-20% of the total mass of the hydrophobic coating. Apply the hydrophobic coating by spraying, with the spray gun pressure controlled at 0.3-0.5 MPa and the spraying distance at 15-25 cm. After coating, allow it to dry in the natural environment for 24-48 hours.

[0036] Furthermore, in step a) above, the edge information of the paint surface in the preprocessed image is extracted using an edge point set algorithm, represented as a discrete point sequence:

[0037] ;

[0038] in, These are the coordinates of the edge points in the image coordinate system.

[0039] Furthermore, in step a) above, the local edge curvature calculation method is applied to each edge point. Take its adjacent points before and after. and The local edge curvature is calculated using the discrete three-point formula. :

[0040] ;

[0041] Among them, forward point distance ,

[0042] Backward distance ,

[0043] Span distance ;

[0044] Then, the pixel coordinates are converted into actual physical coordinates based on the image resolution.

[0045] Furthermore, in step a) above, the edge direction change analysis method is to calculate the tangent direction angle at the edge point. :

[0046] ;

[0047] The rate of change of direction is approximated by the difference between the tangent direction angles at adjacent points:

[0048] ;

[0049] Morphological characteristics of sagging defects require The value is less than 0 and has a large absolute value, showing a continuous downward bending trend.

[0050] Furthermore, in step 3) above, the anti-rust pigment in the primer is selected from one or a mixture of two of zinc phosphate and iron oxide red.

[0051] Furthermore, in step 6) above, the filler is selected from one or a mixture of two of talc powder and mica powder.

[0052] Furthermore, in step 13) above, the hydrophobic agent is selected from fluorinated hydrophobic agents or organosilicon hydrophobic agents.

[0053] By adopting the aforementioned technical solution, the beneficial effects of this invention are as follows: This corrugated guardrail anti-corrosion treatment process first uses a high-pressure water gun to wash away dust, dirt, and loose impurities, then wipes with acetone to remove oil stains and stubborn dirt, and finally dries the surface to ensure it is dry, providing a good foundation for subsequent treatment, enhancing the adhesion between the coating and the guardrail surface, and improving the anti-corrosion effect. Using a grinding wheel of a specific grit to uniformly grind removes rust, scale, and burrs, and controls surface roughness, further increasing the contact area between the coating and the guardrail surface and improving adhesion. Furthermore, the composition and proportion range of the primer, intermediate coat, and topcoat, as well as the stirring speed and time, are specified in detail to ensure the composition of each paint layer is optimal. The coatings are evenly dispersed and have stable performance, allowing each layer to perform its anti-corrosion, protective, and decorative functions. They are first naturally dried and then baked to cure, with precise control over the drying and curing conditions of different paint layers to ensure that each layer is fully dried and cured, achieving optimal physical and chemical properties and improving anti-corrosion durability. The cured topcoat surface is then inspected to promptly identify and repair defects such as sagging, blistering, and pinholes, ensuring coating quality and improving the overall anti-corrosion performance and appearance of the railing. A hydrophobic coating is then applied to the railing surface to further enhance its waterproof and anti-corrosion capabilities, extending its service life. This process can improve the adhesion between the paint and the railing surface while ensuring coating efficiency. Attached Figure Description

[0054] Figure 1 This is a circuit module diagram of an embodiment of the present invention.

[0055] Explanation of reference numerals in the attached figures:

[0056] 1. High-definition industrial camera; 2. Central control unit; 3. Image processing system; 4. Image acquisition module; 5. Wireless communication module; 6. Display screen; 7. Prompt device; 8. Audible and visual alarm. Detailed Implementation

[0057] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0058] The embodiments of the present invention are as follows:

[0059] A corrosion protection process for corrugated guardrails includes the following steps:

[0060] 1) Clean the surface of the corrugated guardrail. First, use a high-pressure water gun at 16MPa to rinse the guardrail surface to remove dust, dirt and loose impurities. Then, use acetone to wipe the guardrail surface to further remove oil and stains that are difficult to rinse off with water. Finally, place the guardrail in a drying equipment at 65℃ for 20 minutes to dry the guardrail surface completely.

[0061] 2) Grind the dried guardrail surface using a 180-mesh grinding wheel to remove rust, scale, and burrs, so that the surface roughness reaches Ra3.2~Ra6.3μm.

[0062] 3) Prepare the primer, which consists of epoxy resin, curing agent, anti-rust pigment and organic solvent. The epoxy resin is bisphenol A type epoxy resin, the curing agent is polyamide, and the organic solvent is xylene. The epoxy resin accounts for 40-60% of the total mass of the primer, preferably 45%, the curing agent accounts for 15-25% of the mass of the epoxy resin, preferably 20%, the anti-rust pigment accounts for 10-20% of the total mass of the primer, preferably 18%, and the organic solvent accounts for 10-30% of the total mass of the primer, preferably 17%. After mixing the components in the specified proportions, stir for 20-40 minutes at a stirring speed of 300-500 r / min to ensure thorough and uniform mixing. The anti-rust pigment in the primer is selected from one or a mixture of two of zinc phosphate and iron oxide red, preferably zinc phosphate.

[0063] 4) Apply the prepared primer to the pretreated guardrail surface by brushing. Use a suitable brush to ensure that the primer evenly covers the guardrail surface. The thickness of the primer coating should be controlled between 20 and 40 μm.

[0064] 5) Place the guardrail with the primer applied in an environment with a temperature of 28℃ and a relative humidity of 65% to air dry for 1.5 hours, and then put it in an oven and bake at a temperature of 90℃ for 45 minutes to allow the primer to fully cure.

[0065] 6) Prepare the intermediate paint, which is composed of polyurethane resin, filler and organic solvent. The polyurethane resin is a two-component polyurethane resin, and the organic solvent is ethylene glycol ethyl ether acetate. The polyurethane resin accounts for 50-70% of the total mass of the intermediate paint, preferably 60%. The filler accounts for 20-30% of the total mass of the intermediate paint, preferably 25%. The organic solvent accounts for 10-20% of the total mass of the intermediate paint, preferably 15%. After mixing the components in proportion, stir for 45 minutes at a stirring speed of 550 r / min to ensure that it is fully dispersed and uniform. The filler is one or a mixture of two of talc powder and mica powder, preferably talc powder.

[0066] 7) Apply intermediate paint to the cured primer surface by spraying. Control the spray gun pressure at 0.6MPa and the spraying distance at 30cm to ensure that the intermediate paint evenly covers the primer surface. The thickness of the intermediate paint coating should be controlled between 40 and 60μm.

[0067] 8) Place the guardrail with the intermediate paint applied in an environment with a temperature of 27℃ and a relative humidity of 50% to air dry for 3 hours, and then put it in an oven and bake at a temperature of 110℃ for 80 minutes to allow the intermediate paint to fully cure.

[0068] 9) Prepare the topcoat, which is composed of fluorocarbon resin, pigment and organic solvent. The organic solvent is methyl isobutyl ketone. The fluorocarbon resin accounts for 60-80% of the total mass of the topcoat, preferably 70%. The pigment accounts for 10-20% of the total mass of the topcoat, preferably 12%. The organic solvent accounts for 10-20% of the total mass of the topcoat, preferably 18%. After mixing the components in the specified proportions, stir for 55 minutes at a stirring speed of 650 r / min to ensure thorough and uniform mixing.

[0069] 10) Apply the topcoat to the cured intermediate paint surface by spraying. Control the spray gun pressure at 0.8MPa and the spraying distance at 32cm to ensure that the topcoat evenly covers the intermediate paint surface. The thickness of the topcoat coating should be controlled between 30 and 50μm.

[0070] 11) Place the painted guardrail in an environment with a temperature of 30℃ and a relative humidity of 55% to dry naturally for 4 hours, and then put it in an oven and bake at a temperature of 130℃ for 110 minutes to allow the paint to fully cure.

[0071] 12) Inspect the cured topcoat surface for defects such as drips, bubbles, and pinholes. If defects are found, lightly sand the defective areas with sandpaper and then reapply the corresponding paint layer for repair.

[0072] 13) Apply a hydrophobic coating with a thickness of 5-10 μm to the surface of the guardrail. The hydrophobic coating is composed of silicone resin and a hydrophobic agent, wherein the silicone resin accounts for 80-90% of the total mass of the hydrophobic coating, preferably 85%, and the hydrophobic agent accounts for 10-20% of the total mass of the hydrophobic coating, preferably 15%. Apply the hydrophobic coating by spraying, with the spray gun pressure controlled at 0.4 MPa and the spraying distance at 20 cm. After coating, allow it to dry in a natural environment for 40 hours. The hydrophobic agent can be a fluorinated hydrophobic agent or a silicone hydrophobic agent, preferably a fluorinated hydrophobic agent.

[0073] This anti-corrosion treatment process for corrugated guardrails begins with high-pressure water jet rinsing to remove dust, dirt, and loose impurities. Next, acetone is used to wipe away oil and stubborn stains. Finally, drying ensures the surface is dry, providing a good foundation for subsequent treatments, enhancing the adhesion between the coating and the guardrail surface, and improving the anti-corrosion effect. A specific grit abrasive wheel is used for uniform polishing to remove rust, scale, and burrs, controlling surface roughness to further increase the contact area between the coating and the guardrail surface, improving adhesion. Furthermore, the composition and proportion range of the primer, intermediate coat, and topcoat, as well as the stirring speed and time, are specified in detail to ensure uniform dispersion and stable performance of each paint layer. Each layer of paint can perform its respective functions of corrosion prevention, protection, and decoration. It is first naturally dried and then baked to cure. The drying and curing conditions of different paint layers are precisely controlled to ensure that each paint layer can be fully dried and cured to achieve the best physical and chemical properties, thereby improving corrosion resistance and durability. The surface of the cured topcoat is then inspected to promptly identify and repair defects such as sagging, blistering, and pinholes, ensuring coating quality and improving the overall corrosion resistance and appearance of the railing. A hydrophobic coating is then applied to the railing surface to further enhance its waterproof and corrosion-resistant capabilities and extend its service life. This process can improve the adhesion between the paint and the railing surface while ensuring coating efficiency.

[0074] In step 4) above, the brushing method includes the following steps:

[0075] 41) Divide the surface of the guardrail into multiple rectangular areas, each no larger than 30cm x 30cm, and paint each area in order from left to right and from top to bottom;

[0076] 42) In each area, first apply a coat evenly in the horizontal direction. After the primer is surface dry, apply a second coat in the vertical direction.

[0077] 43) Use a non-contact laser thickness gauge to dynamically detect the coating thickness. When the detected value exceeds the range of 20-40 μm, immediately adjust it to the target thickness range by recoating or polishing.

[0078] By controlling the coating in different areas to avoid missed areas or repeated coating, uniform coverage is ensured. Cross-coating process enhances coating adhesion and reduces the risk of sagging. Real-time thickness monitoring enables closed-loop control and improves coating quality stability.

[0079] Furthermore, the brush material is a blend of pig bristles and nylon filaments, with pig bristles comprising 60%–70% and nylon filaments comprising 30%–40%. The brush dimensions are: bristle length 15–20 mm, brush head width 5–8 cm, and handle length 25–30 cm. The brushing parameters are: brushing pressure controlled at 0.5–1.0 N / cm², brushing speed 0.3–0.5 m / s, and no more than 15 reciprocating brush strokes per minute. These parameters are carefully controlled to avoid excessive pressure or speed leading to excessive coating thickness or bubble defects.

[0080] In this embodiment, reference Figure 1 As shown, in step 12) above, the inspection method for defects such as sagging, bubbling, and pinholes includes the following steps:

[0081] 121) Install multiple high-definition industrial cameras 1 with a resolution of no less than 5 million pixels above the inspection area to ensure that the field of view of the high-definition industrial cameras 1 can fully cover the surface of the corrugated guardrail without obstruction or blind spots, and there should be a certain overlap between the fields of view of adjacent high-definition industrial cameras 1 to ensure the integrity of the inspection. At the same time, the light intensity of the inspection area should be no less than 500 lux to ensure that the light intensity is uniform and stable.

[0082] 122) Connect the data cable between the high-definition industrial camera 1 and the central control unit 2, ensuring a secure connection and stable signal transmission, and initialize the image processing system 3 in the central control unit 2 and configure parameters such as image storage path, format, and resolution;

[0083] 123) The image processing system 3 is calibrated by taking pictures and processing a wave guardrail with a known defect-free paint surface as a standard sample to form a standard image;

[0084] 124) In the central control unit 2, the image acquisition module 4 is started to control the high-definition industrial camera 1 to continuously capture images of the surface of the wave guardrail paint at a frame rate of 10-20 frames / second to form an inspection image;

[0085] 125) The inspection image data captured by the high-definition industrial camera 1 is transmitted to the central control unit 2 in real time through the wireless communication module 5. The central control unit 2 stores the received inspection images according to the set storage path and format for subsequent query and analysis. At the same time, the captured inspection images are displayed on the display screen 6 in real time for the operator to observe initially.

[0086] 126) The intelligent image processing system 3 performs noise reduction processing on the acquired inspection image, uses the median filtering algorithm to remove noise interference in the image, and then uses the histogram equalization method to enhance the contrast of the image, making the defect features of the paint surface more obvious, thus forming a preprocessed image.

[0087] 127) Image processing system 3 extracts the standard image and the preprocessed image for comparison and identifies defects:

[0088] a. By extracting the edge information of the paint surface in the preprocessed image, and by analyzing the changes in the curvature and direction of the edges, when a local edge is found to be significantly bent downward and the local edge curvature threshold exceeds 0.5 rad / mm, it is determined to be a sagging defect.

[0089] b. Calculate the texture feature parameters of the entropy of the gray-level co-occurrence matrix of local areas in the preprocessed image using a texture analysis algorithm. When the entropy value is greater than 3.5, it is outside the normal range and is judged as a bubbling defect.

[0090] c. By setting a threshold of less than 50 grayscale values ​​through a threshold segmentation algorithm, pinholes are separated from the background. Then, the area and shape parameters of the holes are calculated. When the area of ​​the hole is greater than the set value of 0.01 mm² and the roundness is greater than 0.8, it is judged as a pinhole defect.

[0091] 128) When the image processing system identifies a defect, it immediately sends a signal to the central control unit 2. The central control unit 2 triggers the prompting device 7, which displays the location, type, and severity of the defect on the display screen 6. At the same time, the audible and visual alarm 8 sounds an alarm and flashes a light to alert the operator.

[0092] Multiple high-definition industrial cameras 1 are installed to ensure full coverage of the field of view without any blind spots. Adjacent high-definition industrial cameras 1 have overlapping fields of view, while ensuring uniform and stable illumination intensity to provide a clear image foundation for accurate defect detection. Securely connected data cables ensure stable signal transmission. The image processing system of the central control unit 2 is initialized and its parameters configured to ensure smooth image acquisition and processing. Standard samples are used for calibration to create standard images, providing accurate reference for subsequent comparison with inspection images and improving the accuracy of defect identification. The high-definition industrial cameras 1 are controlled to continuously capture images at a certain frame rate, transmitting them in real time to the central control unit 2 for storage. The display screen 6 facilitates initial observation by operators, enabling them to promptly identify potential problems. Median filtering for noise reduction and histogram equalization enhance contrast, making the defect features of the topcoat surface more apparent and facilitating subsequent defect identification. Specific algorithms are used to identify different types of defects (sagging, blistering, pinholes). By analyzing parameters such as edge information, texture features, and grayscale values, the defect type is accurately determined, improving the accuracy and reliability of detection. Once a defect is identified, a signal is immediately sent to the central control unit 2, triggering the prompting device 7. The defect information is displayed on the display screen 6, and an audible and visual alarm is issued to remind operators to handle the issue promptly and ensure production quality.

[0093] Furthermore, in step a) above, the edge information of the paint surface in the preprocessed image is extracted using an edge point set algorithm, represented as a discrete point sequence:

[0094] ;

[0095] in, These are the coordinates of the edge points in the image coordinate system.

[0096] By extracting edge information of the paint surface in the preprocessed image using the edge point set algorithm and representing it in the form of a discrete point sequence, the coordinate information of the edge points can be accurately obtained, providing a precise data foundation for subsequent edge curvature calculation and direction change analysis, which helps to more accurately identify drip defects.

[0097] Furthermore, in step a) above, the local edge curvature calculation method is applied to each edge point. Take its adjacent points before and after. and The local edge curvature is calculated using the discrete three-point formula. :

[0098] ;

[0099] Among them, forward point distance ,

[0100] Backward distance ,

[0101] Span distance ;

[0102] Then, the pixel coordinates are converted into actual physical coordinates based on the image resolution.

[0103] The discrete three-point formula is used to calculate the local edge curvature, and the calculation methods of forward point distance, backward point distance and cross point distance are explained in detail. Finally, the pixel coordinates are converted into actual physical coordinates. This calculation method can accurately reflect the curvature of the edge, combine image information with actual physical dimensions, and more intuitively judge whether the curvature threshold of the drip defect has been reached, thus improving the accuracy of defect identification.

[0104] Furthermore, in step a) above, the edge direction change analysis method is to calculate the tangent direction angle at the edge point. :

[0105] ;

[0106] The rate of change of direction is approximated by the difference between the tangent direction angles at adjacent points:

[0107] ;

[0108] Morphological characteristics of sagging defects require The value is less than 0 and has a large absolute value, showing a continuous downward bending trend.

[0109] By calculating the tangent direction angle and the rate of change of direction at the edge point, the morphological characteristics requirements of the drip defect were clarified. (If the value is less than 0 and the absolute value is large, it shows a continuous downward bending trend), which can more accurately identify sag defects from the perspective of directional change. Combined with curvature analysis, it can further improve the accuracy and reliability of sag defect identification.

[0110] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0111] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0112] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0113] Although the invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the invention without departing from the spirit and scope of the invention as defined in the appended claims, all of which shall be within the scope of protection of the invention.

Claims

1. A process for corrosion protection of a wavelike barrier, characterized in that: The method comprises the following steps: 1) surface cleaning treatment of the wave-shaped guardrail, first, using a high-pressure water gun to flush the surface of the guardrail at a pressure of not less than 15 MPa to remove dust, soil and loose impurities attached to the surface; then using acetone to wipe the surface of the guardrail to further remove oil stains and stains difficult to be washed away by water; finally, placing the guardrail in a drying equipment with a temperature of 50-70 DEG C for drying for 15-30 minutes to completely dry the surface of the guardrail; 2) polishing treatment of the surface of the dried guardrail, using a sand wheel with a particle size of 120-220 to uniformly polish the surface of the guardrail to remove the rust layer, oxide scale and burrs on the surface of the guardrail, so that the surface roughness of the guardrail reaches Ra3.2-Ra6.3 mu m; 3) preparation of a primer, the primer is composed of epoxy resin, curing agent, anti-rust pigment and organic solvent, wherein the epoxy resin accounts for 40-60% of the total mass of the primer, the curing agent accounts for 15-25% of the mass of the epoxy resin, the anti-rust pigment accounts for 10-20% of the total mass of the primer, and the organic solvent accounts for 10-30% of the total mass of the primer; after mixing the components in proportion, stirring at a stirring speed of 300-500 r / min for 20-40 minutes to fully mix and uniformly disperse them; 4) using a brushing method to apply the prepared primer to the surface of the pretreated guardrail, using a suitable brush to ensure that the primer uniformly covers the surface of the guardrail during brushing, and the thickness of the primer coating is controlled to be 20-40 mu m; The brushing method comprises the following steps: 41) dividing the surface of the guardrail into multiple rectangular regions, each region has a size of not more than 30 cm x 30 cm, and brushing is performed in each region in the order from left to right and from top to bottom; 42) in each region, first, uniformly brushing in the horizontal direction for one time, and after the primer surface dries, brushing in the vertical direction for a second time; 43) using a non-contact laser thickness gauge to dynamically detect the coating thickness, and when the detected value exceeds the range of 20-40 mu m, immediately adjusting to the target thickness range by re-coating or polishing; 5) placing the guardrail with the applied primer in an environment with a temperature of 20-30 DEG C and a relative humidity of 50-70% for natural drying for 1-2 hours, and then placing it in an oven for baking at a temperature of 80-100 DEG C for 30-60 minutes to completely cure the primer; 6) preparation of an intermediate paint, the intermediate paint is composed of polyurethane resin, filler and organic solvent, wherein the polyurethane resin accounts for 50-70% of the total mass of the intermediate paint, the filler accounts for 20-30% of the total mass of the intermediate paint, and the organic solvent accounts for 10-20% of the total mass of the intermediate paint; after mixing the components in proportion, stirring at a stirring speed of 400-600 r / min for 30-50 minutes to fully disperse and uniformly disperse them; 7) using a spraying method to apply the intermediate paint to the surface of the cured primer, the spraying gun pressure is controlled to be 0.5-0.7 MPa, the spraying distance is 25-35 cm, and the intermediate paint uniformly covers the surface of the primer, and the thickness of the intermediate paint coating is controlled to be 40-60 mu m; 8) the guardrail coated with the intermediate paint is placed in an environment with a temperature of 20-30°C and a relative humidity of 50-70% for natural drying for 2-3 hours, and then placed in an oven for baking at a temperature of 100-120°C for 60-90 minutes to completely cure the intermediate paint; 9) the topcoat is prepared, which is composed of fluorocarbon resin, pigment and organic solvent, wherein the fluorocarbon resin accounts for 60-80% of the total mass of the topcoat, the pigment accounts for 10-20% of the total mass of the topcoat, and the organic solvent accounts for 10-20% of the total mass of the topcoat; after mixing the components in proportion, stirring is carried out at a stirring speed of 500-700 r / min for 40-60 minutes to fully mix and uniformly distribute them; 10) the topcoat is coated on the surface of the cured intermediate paint by spraying, the spraying gun pressure is controlled at 0.6-0.8 MPa, the spraying distance is 30-40 cm, and the topcoat is ensured to uniformly cover the surface of the intermediate paint, and the thickness of the topcoat layer is controlled at 30-50 μm; 11) the guardrail coated with the topcoat is placed in an environment with a temperature of 20-30°C and a relative humidity of 50-70% for natural drying for 3-4 hours, and then placed in an oven for baking at a temperature of 120-140°C for 90-120 minutes to completely cure the topcoat; 12) the surface of the cured topcoat is inspected to check whether there are defects such as sagging, blistering and pinholes, if there are defects, the defect positions are lightly polished with sandpaper, and then the corresponding paint layer is re-coated for repair; The inspection method of the sagging, blistering and pinhole defects comprises the following steps: 121) a plurality of high-definition industrial cameras with a resolution of not less than 5 million pixels are installed above the inspection area to ensure that the field of view of the high-definition industrial cameras can fully cover the topcoat surface of the wave-shaped guardrail without any blind area, and there is a certain overlapping area between the fields of view of adjacent high-definition industrial cameras to ensure the integrity of the inspection, and at the same time, the light intensity of the inspection area is not less than 500 lux to ensure that the light intensity is uniform and stable; 122) the data line connecting the high-definition industrial camera and the central control unit is ensured to be firmly connected and the signal transmission is stable, and the image processing system in the central control unit is initialized and the storage path, format and resolution of the image are configured; 123) the image processing system is calibrated, and a wave-shaped guardrail with a known defect-free topcoat surface is used as a standard sample for shooting and processing to form a standard image; 124) the image acquisition module in the central control unit is started to control the high-definition industrial camera to continuously shoot the image of the topcoat surface of the wave-shaped guardrail at a frame rate of 10-20 frames / second to form an inspection image; 125) the inspection image data shot by the high-definition industrial camera is transmitted in real time to the central control unit through the data line or the wireless communication module, the central control unit stores the received inspection image according to the set storage path and format for subsequent query and analysis, and at the same time, the shot inspection image is displayed in real time on the display screen for the convenience of the operator to make a preliminary observation. 126) The intelligent image processing system denoises the collected inspection image, removes noise interference in the image by using a median filter algorithm, and then enhances the contrast of the image by a histogram equalization method, so that the defect features on the surface of the topcoat are more obvious, and a preprocessed image is formed. 127) The image processing system extracts the standard image and the preprocessed image for comparison and identifies defects: a. By extracting the edge information of the surface of the topcoat in the preprocessed image, the curvature and direction change of the edge are analyzed, and when a local edge is found to be obviously bent downward and the local edge curvature threshold exceeds 0.5 rad / mm, it is determined to be a sagging defect; b. By a texture analysis algorithm, the entropy texture feature parameter of the gray level co-occurrence matrix of the local area in the preprocessed image is calculated, and when the entropy value is greater than 3.5, it is outside the normal range, and it is determined to be a blister defect; c. By a threshold segmentation algorithm, a threshold value of less than 50 is set to separate the pinholes from the background, and then the area and shape parameters of the holes are calculated, and when the hole area is greater than the set value of 0.01 mm² and the circularity is greater than 0.8, it is determined to be a pinhole defect; 128) When the image processing system identifies a defect, it immediately sends a signal to the central control unit, which triggers the prompt device to display the location, type and severity of the defect on the display screen, and the audible and visual alarm emits an alarm sound and flashing light to remind the operator; 13) A hydrophobic coating with a thickness of 5-10 μm is coated on the surface of the guardrail, which is composed of silicone resin and hydrophobic agent, wherein the silicone resin accounts for 80-90% of the total mass of the hydrophobic coating, and the hydrophobic agent accounts for 10-20% of the total mass of the hydrophobic coating; the hydrophobic coating is coated by spraying, the spray gun pressure is controlled at 0.3-0.5 MPa, the spraying distance is 15-25 cm, and the coating is dried in the natural environment for 24-48 hours.

2. The corrugated guardrail anti-corrosion treatment process of claim 1, wherein: In the above step a), the extraction of the edge information of the surface of the topcoat in the preprocessed image is extracted by an edge point set algorithm, which is represented as a discrete point sequence: ； wherein, are the edge point coordinates in the image coordinate system.

3. The corrugated guardrail anti-corrosion treatment process of claim 2, wherein: In the above step a), the local edge curvature is calculated in the following manner for each edge point , taking the neighboring points and before and after the edge point, and using the discrete three-point formula to calculate the local edge curvature : ； wherein the forward point distance , Backward point distance , Cross-point distance ; Then the pixel coordinates are converted into actual physical coordinates according to the image resolution.

4. The corrugated guardrail anti-corrosion treatment process of claim 3, wherein: In the step a) above, the edge direction change analysis method is to calculate the tangent direction angle at the edge point : ； The direction change rate is approximated by the difference between the tangent direction angles of adjacent points: ； Morphological characteristics requirements of sagging defects <0 and the absolute value is large, showing a sustained downward bending trend.

5. The corrugated guardrail anti-corrosion process of claim 1, wherein: In the above step 3), the rust-proof pigment in the primer is selected from one or a mixture of the other of zinc phosphate and red iron oxide.

6. The corrugated guardrail anti-corrosion process of claim 1, wherein: In the above step 6), the filler is selected from one or a mixture of the other of talc powder and mica powder.

7. The corrugated guardrail anti-corrosion process of claim 1, wherein: In the above step 13), the hydrophobic agent is selected from fluorine-containing hydrophobic agent or silicone hydrophobic agent.

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