Anti-corrosion method for flaw detection of medium-thickness steel plate

Abstract

The invention discloses an anti-corrosion method for flaw detection of a medium-thickness steel plate. Domestic water and a water-based anti-rust solution are mixed to serve as a coupling agent for flaw detection to be sprayed on the steel plate; after flaw detection is completed, a wear-resistant scraping plate is tightly attached to the surface of the flaw detection plate, and the coupling agent is scraped; and in the process of transferring the flaw detection plate from the cooling bed to the side conveying ground roller, the flaw detection plate is kept in an inclined posture. The problem that an existing medium-thickness steel plate is prone to rusting after being subjected to flaw detection by using domestic water as a coupling agent is solved.

Description

Technical Field

[0001] The invention relates to the technical field of surface quality inspection of medium and thick steel plates, in particular to an anti-corrosion method for flaw detection of medium and thick steel plates. Background Art

[0002] At present, ultrasonic nondestructive testing is used for flaw detection of steel plates. In practical applications, as a medium for ultrasonic propagation, the selection of coupling agent is crucial to the flaw detection effect. Ordinary domestic water is often used as a coupling agent for flaw detection of steel plates due to its economy and easy availability. However, for medium and thick steel plates, this choice has obvious limitations. Since medium and thick steel plates usually have a large surface area and weight, when domestic water is used as a coupling agent, a large amount of water stains are likely to remain on the surface of the steel plate, and it is not easy to dry quickly. This not only increases the risk of rust on the steel plate, but also makes it difficult to meet the special needs of customers for qualified flaw detection and no surface rust.

[0003] During the flaw detection process, medium and thick steel plates are pushed to the bottom of the flaw detector by starting the ground roller, and the flaw detection switch is started. The flaw detection device equipped with 60 sets of probes is pressed down close to the steel plate for detection. In order to ensure the flaw detection effect and protect the probes, a large amount of water must be used as a coupling agent on the surface of the steel plate. Therefore, a clean circulating water system is installed under the flaw detector. The system ensures sufficient supply and uniform distribution of the coupling agent by continuously spraying the surface of the steel plate.

[0004] Since there is no device to clean water stains on the steel plates that have been inspected, the residual water stains not only have no anti-rust effect, but are likely to promote oxidation on the surface of the steel plates and accelerate rust. In order to prevent large areas of rust on the surface of the steel plates before leaving the warehouse, it is necessary to manually clean the residual water stains on the surface of the steel plates with a mop. Due to the large surface area and heavy weight of medium and thick steel plates, manual cleaning of water stains is not only inefficient, but also difficult to ensure the cleaning quality. If the cleaning is not clean or the steel plates are left for too long after cleaning and are not shipped in time, different degrees of rust may appear on the surface of the steel plates. This not only affects the appearance and durability of the steel plates, but may also have an adverse effect on the overall quality of the product, thereby causing quality disputes and return risks.

[0005] Therefore, for the flaw detection of medium and thick steel plates, how to effectively prevent the steel plates from rusting while ensuring the flaw detection effect has become an urgent problem to be solved. Summary of the invention

[0006] The purpose of the present invention is to provide a method for preventing rust in flaw detection of medium and thick steel plates, which can solve the problem that medium and thick steel plates are prone to rust after flaw detection using domestic water as a coupling agent.

[0007] In order to solve the above problems, the technical solution adopted by the present invention is: this anti-rust method for flaw detection of medium and thick steel plates uses a mixture of domestic water and anti-rust liquid as a coupling agent for flaw detection to spray the steel plate; after the flaw detection is completed, a wear-resistant scraper is used to closely fit the surface of the flaw detection plate to scrape off the coupling agent; during the process of transferring the flaw detection plate from the cooling bed to the side conveying roller, the flaw detection plate is kept in an inclined posture.

[0008] In some possible implementation schemes, the domestic water and the water-based rust preventive liquid are mixed in a ratio of 10:1.

[0009] In some possible implementation schemes, the wear-resistant scraper is fixed on the flaw detector and is raised and lowered along with the flaw detector. The scratching depth between the wear-resistant scraper and the surface of the flaw detection plate is 0.05-0.1 cm.

[0010] In some possible implementations, the angle of the tilted posture is 20°.

[0011] In some possible implementations, the tilting posture is maintained for at least 10 seconds.

[0012] In some possible implementation schemes, the water pressure of the spraying is not less than 3 kilograms.

[0013] In some possible implementation schemes, two spray pipes are provided, wherein the nozzle of one spray pipe is vertically downward, and the nozzle of the other spray pipe is inclined toward the incoming direction of the steel plate; the nozzles of the two spray pipes are staggered with each other.

[0014] In some possible implementation schemes, a water reservoir is provided under the cooling bed, and the coupling agent in the water reservoir is pumped to the spray pipe by a water pump, and the coupling agent after spraying is recovered into the water reservoir for recycling.

[0015] In some possible implementation schemes, an inclined transfer device is provided between the cooling bed and the side conveying rollers, and the inclined transfer device includes a steel pulling mechanism, a return device, an inclined roller, a plate connector, a plate stacking machine beam, a wire rope, a pendant, and a cylinder; The steel pulling mechanism is used to hold one side of the flaw detection plate and pull the flaw detection plate through the inclined roller to the conveying roller; The return device is used for resetting the steel-drawing mechanism; The plate connector is slidably connected to the crossbeam of the plate stacking machine and is used to clamp the other side of the flaw detection plate; The pendant is connected to the plate connector via the steel wire rope and is used for resetting the plate connector; The cylinder is used to control the opening degree of the plate connector.

[0016] In some possible implementation schemes, the steel pulling mechanism includes a motor, a winding wheel, a traction rope, and a push rod. The motor drives the winding wheel to rotate, and the two ends of the traction rope are respectively connected to the winding wheel and the push rod.

[0017] In the above-mentioned technical solution of the anti-corrosion method for flaw detection of medium and thick steel plates, a more specific technical solution may also be: Due to the adoption of the above technical solution, the present invention has the following beneficial effects compared with the prior art: 1. This method uses a mixture of domestic water and a safe, environmentally friendly and pollution-free water-based anti-rust liquid as a coupling agent for flaw detection, and by accurately controlling the ratio of domestic water to the water-based anti-rust liquid, it can be ensured that the coupling agent has good ultrasonic propagation performance and a certain anti-rust ability. Even if there is coupling agent remaining on the surface of the steel plate, it is not easy to cause the steel plate to rust. After the flaw detection is completed, a wear-resistant scraper is used to closely fit the surface of the steel plate to scrape off the coupling agent. Compared with manual cleaning with a mop, this method is not only more efficient, but also can more thoroughly remove the residual moisture and coupling agent on the surface of the steel plate, reducing the risk of rust on the steel plate. In the process of transferring the flaw detection plate from the cooling bed to the side conveying roller, the flaw detection plate is kept in an inclined posture, so that the residual moisture on the surface of the steel plate is more likely to flow to one side under the action of gravity, which helps to further drain the residual moisture on the surface of the steel plate and reduce the residence time of moisture on the surface of the steel plate, thereby reducing the possibility of rust on the steel plate.

[0018] 2. The wear-resistant scraper rises and falls with the flaw detector, and can be closely attached to the surface of the flaw detection plate in time after the flaw detection is completed, and the residual coupling agent can be quickly removed by scraping. The scraping depth between the wear-resistant scraper and the flaw detection plate surface can ensure that the coupling agent is effectively removed without causing damage to the steel plate surface.

[0019] 3. The angle and time selection of the tilting posture can ensure that the moisture has enough time to be discharged smoothly, and will not cause the steel plate to slide or overturn during the transfer process due to excessive angle. It can also reduce the residence time of moisture on the surface of the steel plate and reduce the risk of rusting of the steel plate.

[0020] 4. Sufficient spraying water pressure can ensure that the coupling agent penetrates into the tiny gaps on the surface of the steel plate, thereby covering the surface of the steel plate more comprehensively. This helps to discover potential defects, improve the sensitivity and accuracy of flaw detection, and ensure that during the spraying process, the moisture on the surface of the steel plate is more fully mixed with the water-based anti-rust liquid to form a protective film. When the steel plate is tilted to drain, this protective film helps to reduce the residual moisture, thereby reducing the risk of rust on the steel plate.

[0021] 5. The arrangement of the spray nozzles reduces the blind area of ​​spraying, ensuring that all parts of the steel plate can be fully sprayed, and can also improve the spraying efficiency and effect, and enhance the anti-corrosion ability of the steel plate surface.

[0022] 6. The structural setting of the inclined transfer device improves the transfer efficiency and can be applied to various types of flaw detection plates. It has strong adaptability and simple operation. The cylinder is used to adjust the opening degree of the plate connector to facilitate the reception of steel plates of different thicknesses and meet the needs of steel plates of different specifications. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a top view of the on-site layout of the flaw detection equipment used in this anti-corrosion method for flaw detection of medium and thick steel plates.

[0024] Figure 2 It is a structural schematic diagram of the inclined transfer device.

[0025] Figure 3 These are comparison photos after flaw detection using a mixed solvent made of domestic water and a water-based rust-proof liquid in a ratio of 6:1 and domestic water as coupling agents.

[0026] Figure 4 These are comparison photos after flaw detection using a mixed solvent made of domestic water and a water-based rust-proof liquid in a ratio of 8:1 and domestic water as coupling agents.

[0027] Figure 5 This is a photo of the surface condition of medium and thick steel plates after flaw detection using a mixed solvent of domestic water and water-based rust-proof liquid in a ratio of 8:1, and then left for 16 hours.

[0028] Figure 6 This is a photo of the surface condition of medium and thick steel plates after flaw detection using a mixed solvent of domestic water and water-based rust-proof liquid in a ratio of 10:1, and then left for 16 hours.

[0029] Figure 7 This is a photo of the surface condition of medium and thick steel plates after flaw detection using a mixed solvent of domestic water and water-based rust-proof liquid in a ratio of 12:1, and then left for 16 hours.

[0030] Explanation of the numbers in the attached figures: 1. Cooling bed; 2. Ground roller; 3. Spray pipe; 4. Water reservoir; 5. Flaw detector; 6. Wear-resistant scraper; 7. Flaw detector plate; 8. Steel pulling mechanism; 9. Plate connector; 10. Side conveying ground roller; 11. Returner; 12. Inclined roller table; 13. Cylinder; 14. Stacker beam; 15. Wire rope; 16. Pulley; 17. Stacker frame. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with the accompanying drawings: Figure 1The flaw detection equipment shown includes a cooling bed, a spray pipe, a water reservoir, a flaw detector, a wear-resistant scraper, an inclined transfer device, and a side conveying roller, wherein the cooling bed is used to place medium and thick steel plates, and the steel plates are conveyed by the rollers. The flaw detector is arranged across the cooling bed, and a water reservoir for storing coupling agent is arranged below the flaw detector and the cooling bed. The water reservoir is connected to the spray pipe located upstream of the flaw detector through a pipe and a water pump to form a coupling agent circulation system. There are two groups of spray pipes in this embodiment, one group of which has 14 nozzles inclined in the direction of incoming and outgoing materials; the other group is vertically downward, with 9 nozzles. The positions of the two groups of nozzles are staggered, and the two groups of spray pipes share a valve and are opened at the same time to ensure that all parts of the steel plate surface can be evenly covered. A wear-resistant scraper is fixed on the crossbeam of the flaw detector. The wear-resistant scraper moves with the movement of the flaw detector. When the flaw detector performs flaw detection, the wear-resistant scraper maintains a certain contact depth with the surface of the steel plate to scrape off the coupling agent residue on the surface of the flaw detection plate after flaw detection. The scraped coupling agent falls into the reservoir for recycling. A side conveying roller is set on the side of the cooling bed downstream of the flaw detector to store the flaw detection plate. To ensure that there is no residual coupling agent on the flaw detection plate, the horizontal height of the side conveying roller must be higher than the height of the cooling bed. An inclined transfer device is set between the cooling bed and the side conveying roller to transfer the flaw detection plate to the side conveying roller.

[0032] Figure 2 The inclined transfer device shown includes a steel pulling mechanism, a return device, an inclined roller, a plate connector, a plate stacking machine crossbeam, a wire rope, a pendant and a cylinder, etc., wherein the steel pulling mechanism is used to transfer the flaw detection plate on the pulling cooling bed to the side conveying roller via the inclined roller, and the steel pulling mechanism mainly includes a motor, a winding wheel, a traction rope and a push rod. The motor is used as a power source to drive the winding wheel to rotate, and then the winding wheel and the push rod are connected through the two ends of the traction rope respectively to pull the push rod to move. When the motor is started, the winding wheel rotates, the traction rope is wound or released, and the push rod is driven to support one side of the flaw detection plate and pull it along the inclined roller to the side conveying roller. The return device is used to reset the steel pulling mechanism, and a spring or other automatically reset component can be used as the return device. The plate connector is higher than the cooling bed, and the inclined roller is tilted upward from the cooling bed to the plate connector. The inclination of the inclined roller in this embodiment is 20°. The crossbeam of the plate stacking machine is located above the side conveying roller, and the plate connector is slidably connected to the crossbeam of the plate stacking machine. In order to facilitate the resetting of the plate connector, pulleys are provided at the top of the principle cooling bed of the plate connector frame located above the cross beam of the plate connector and at the bottom close to the cooling bed, and the plate connector and the pendant are respectively connected by a steel wire rope spanning the two pulleys, and the plate connector is reset by the deadweight of the pendant. In some possible embodiments, the plate connector is a movable "L"-shaped clamp, including a fixed clamp and a movable clamp hinged at one end, and the movable clamp is connected to the cylinder, and the expansion and contraction of the cylinder is used to adjust the opening degree of the plate connector to help the plate connector receive steel plates of different thicknesses.

[0033] When the inclined transfer device is working, the top rod is used to support one end of the flaw detection plate, the motor is started, and the traction rope is pulled to drive the top rod to push the flaw detection plate along the inclined roller to the plate connector. After the plate connector receives the steel plate, it stays for 10 seconds and uses the inclined 20° angle to drain the coupling agent remaining on the flaw detection plate. Then, the steel pulling mechanism continues to pull the flaw detection plate forward until it is pushed to the end of the beam of the stacking machine. The plate connector opens, and the flaw detection plate falls on the side conveying roller under the beam of the stacking machine due to gravity. After the steel plate falls, the dead weight of the pendant sends the plate connector back to the front end of the beam to continue to receive the next steel plate. The next steel plate is sent over according to the same steps and falls on the previous steel plate. According to the weight of the steel plate, a maximum of 6 plates with a thickness of less than 10 mm can be stacked, which saves time for the storage of steel plates compared to passing plates one by one.

[0034] The anti-corrosion method for flaw detection of medium and thick steel plates includes the following steps: First, the preparation of the coupling agent is a key step in the method of the present invention. The present invention uses domestic water and water-based rust-proof liquid to mix in a weight ratio of 10:1 to prepare a coupling agent for flaw detection. This ratio is the best ratio obtained after multiple experimental verifications, which can ensure that the surface of the steel plate is smooth and free of traces. Specifically, the water-based rust-proof liquid is added to the reservoir of the circulating water system before the production of the flaw detection plate, and is injected into the reservoir in a ratio of 10:1 between domestic water and water-based rust-proof liquid. Since the circulating water circulates, the water-based rust-proof liquid naturally dissolves during the flow process without additional stirring. In order to ensure the quality of the coupling agent, the proportion of the ingredients will be tested before each production to ensure that it meets the use standards. Experiments show that if the proportion of water-based rust-proof liquid is too large, there will be traces of liquid residue on the surface of the steel plate, while if the proportion is too small, yellow rust will appear on the surface of the steel plate.

[0035] After the coupling agent is prepared, the flaw detection operation phase begins. The flaw detector is ready, and its probe will be used to detect defects inside the steel plate. During the flaw detection operation, the medium and thick steel plates to be inspected on the cooling bed need to be sprayed continuously. The water pressure of the spraying is not less than 3 kg, and the total water supply pipe diameter is 150mm to ensure sufficient water pressure and water volume. After the spraying system is started, the coupling agent is evenly sprayed on the surface of the steel plate to form a thin coupling layer. This step not only meets the needs of flaw detection, but also enables the coupling agent to better adhere to the surface of the steel plate, preparing for the next flaw detection operation. At the same time, the spraying operation can effectively prevent the high temperature of the steel plate from affecting and damaging the measurement accuracy of the probe.

[0036] At the same time, the flaw detector descends and starts working, and its probe moves on the steel plate, contacts the coupling layer and generates reflected waves. These reflected waves are received and analyzed by the flaw detector, so as to accurately determine whether the steel plate has defects.

[0037] After the flaw detection is completed, the coupling agent is scraped off. At this time, the wear-resistant scraper fixed on the crossbeam of the flaw detector starts to work. The three steps of spraying, flaw detection and scraping the coupling agent are carried out simultaneously, ensuring the continuity and efficiency of the flaw detection process. The wear-resistant scraper can be made of wear-resistant rubber or obsolete belt rubber, which not only reduces the production cost but also ensures good wear resistance. When working, the scraper has a depth of 0.05 to 0.1 cm in contact with the surface of the flaw detection plate, scraping off the coupling water and the impurities therein and making them fall into the water reservoir.

[0038] The recycled coupling water is treated and then pumped up by a pump and injected into the spray pipe for recycling. This not only reduces the waste of water resources, but also reduces production costs. At the same time, since water-based anti-rust liquid is added to the coupling agent, the recycled coupling water still has a certain anti-rust performance, which further ensures the anti-rust effect of the steel plate.

[0039] The flaw detection plate on the cooling bed is transferred to the side conveying roller by the tilting transfer device. During the transfer process, the steel drawing machine pulls the flaw detection plate from the cooling bed to the plate connector above the crossbeam of the plate stacking machine at the side conveying roller. After the plate connector receives the steel plate, it is driven by the steel drawing machine to move to the end of the roller side. During this movement, the steel plate and the ground roller plane always maintain a 20° angle. In addition to the function of draining the residual water on the surface of the steel plate, the tilting device also has the function of stacking the plates. The angle of the tilting posture should not be too large, which is not conducive to stacking the plates. The steel plate is kept in the tilted posture for at least 10 seconds, so that the residual coupling water flows into the ditch along the oblique angle. The holding time of the tilted posture can be adjusted in real time in manual mode according to the actual situation. The plate connector is connected to the pendant with a wire rope. After the steel plate is lowered to the ground roller, the steel plate is separated from the plate connector, and the plate connector automatically returns to its position by the gravity of the pendant to receive the next steel plate. In addition, when the plate connector is not returning smoothly, the cylinder is used to help the plate connector return. Another function of the cylinder is to adjust the opening degree of the plate connector to ensure that it can receive steel plates of different thicknesses.

[0040] In order to optimize the proportion of coupling agent, the applicant conducted several tests. During the test, domestic water and water-based anti-rust liquid were blended into mixed solvents in different proportions and sprayed on steel plates for flaw detection comparison. In the first test, domestic water and water-based anti-rust liquid were blended into a mixed solvent in a ratio of 6:1. The evenly stirred mixed solvent was sprayed on half of the steel plate, and the other half was sprayed with ordinary domestic water, and flaw detection was performed with a handheld flaw detector. It has been verified that the use of mixed solvents as coupling agents will not affect the normal flaw detection function, and the flaw detection results are consistent with those of domestic water as a coupling agent. After completing the flaw detection comparison, the steel plate was left for 3 hours and then observed. Figure 3As shown in the figure, the steel plate tested with mixed solvents showed no rust, but the residual traces of liquid were obvious. The steel plate tested with domestic water showed obvious rust. In the second test, domestic water and water-based rust-proof liquid were mixed into a mixed solvent in a ratio of 8:1. After the test, it was observed that Figure 4 As shown, the steel plate tested with mixed solvents showed no rust and the traces of residual liquid were much reduced, while the steel plate tested with domestic water showed obvious rust.

[0041] After that, the flaw detection of mixed solvents with a ratio of 8:1, 10:1, and 12:1 was compared, and none of them affected the normal flaw detection work and flaw detection results. After the three test steel plates with mixed solvents with a ratio of 8:1, 10:1, and 12:1 were left for 16 hours, it was found through observation and comparison that the flaw detection with mixed water with a ratio of 10:1 did not affect the normal flaw detection operation, no rust was found on the steel plate surface, and the residual traces of liquid were light, and the flaw detection effect was the best. Figures 5 to 7 The water-based anti-rust liquid used in the embodiment is FXY-01 water-based anti-rust liquid purchased from Guangxi Gangrui Technology Co., Ltd. The water-based anti-rust liquid is an environmentally friendly water-based anti-rust agent. Other embodiments may also use other commercially available water-based anti-rust liquids.

[0042] The present invention successfully solves the problem of easy rust on the surface of plates after ultrasonic flaw detection in the steel industry's medium and thick plate production line by using a mixed solvent in a specific proportion as a coupling agent, combined with a wear-resistant scraper scraper and an inclined transfer device. The implementation of the present invention is not only low-cost, environmentally friendly and efficient, but also can significantly reduce the labor intensity of workers, improve the quality of steel plates and user satisfaction. After using this method, quality complaints caused by yellowing and rusting of the steel plate surface are eliminated, meeting customer needs.

Claims

1. A method for preventing corrosion by flaw detection of medium and thick steel plates, characterized in that: A mixture of domestic water and anti-rust liquid is used as a coupling agent for flaw detection to spray the steel plate; after the flaw detection is completed, a wear-resistant scraper is used to closely fit the surface of the flaw detection plate to scrape off the coupling agent; during the process of the flaw detection plate being transferred from the cooling bed to the side conveying roller, the flaw detection plate is kept in an inclined posture.

2. The anti-corrosion method for flaw detection of medium and thick steel plates according to claim 1, characterized in that: The domestic water and the water-based rust-proof liquid are mixed in a ratio of 10:

1.

3. The anti-corrosion method for flaw detection of medium and thick steel plates according to claim 1 or 2, characterized in that: The wear-resistant scraper is fixed on the flaw detector and rises and falls with the flaw detector. The scratching depth between the wear-resistant scraper and the surface of the flaw detection plate is 0.05 to 0.1 cm.

4. The anti-corrosion method for flaw detection of medium and thick steel plates according to claim 3, characterized in that: The angle of the tilted posture is 20°.

5. The anti-corrosion method for flaw detection of medium and thick steel plates according to claim 4, characterized in that: The tilted posture should be maintained for at least 10 seconds.

6. The anti-corrosion method for flaw detection of medium and thick steel plates according to claim 1, characterized in that: The water pressure of the spray shall not be less than 3 kg.

7. The anti-corrosion method for flaw detection of medium and thick steel plates according to claim 6, characterized in that: Two spray pipes are provided, the nozzle of one of the spray pipes is vertically downward, and the nozzle of the other spray pipe is inclined toward the incoming direction of the steel plate; the nozzles of the two spray pipes are staggered with each other.

8. The method for preventing corrosion by flaw detection of medium and thick steel plates according to claim 7, characterized in that: A water reservoir is provided under the cooling bed. The coupling agent in the water reservoir is pumped to the spray pipe by a water pump, and the coupling agent after spraying is recovered into the water reservoir for recycling.

9. The anti-corrosion method for flaw detection of medium and thick steel plates according to claim 1, characterized in that: An inclined transfer device is arranged between the cooling bed and the side conveying rollers, and the inclined transfer device comprises a steel drawing mechanism, a return device, an inclined roller, a plate connector, a plate stacking machine beam, a steel wire rope, a pendant, and a cylinder; The steel pulling mechanism is used to hold one side of the flaw detection plate and pull the flaw detection plate through the inclined roller to the conveying roller; The return device is used for resetting the steel-drawing mechanism; The plate connector is slidably connected to the crossbeam of the plate stacking machine and is used to clamp the other side of the flaw detection plate; The pendant is connected to the plate connector via the steel wire rope and is used for resetting the plate connector; The cylinder is used to control the opening degree of the plate connector.

10. The method for preventing corrosion by flaw detection of medium and thick steel plates according to claim 9, characterized in that: The steel pulling mechanism comprises a motor, a winding wheel, a traction rope and a push rod. The motor drives the winding wheel to rotate, and the two ends of the traction rope are respectively connected to the winding wheel and the push rod.

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