Apparatus and method for controlling surface defects of an alloyed hot-dip galvanized steel sheet

Abstract

The present application relates to the technical field of steel material processing, and more particularly to a kind of alloying hot-dip galvanized steel plate surface defect control device and method, device includes sequentially connected inlet input device, integrated galvanizing device and outlet output device;Integrated galvanizing device outer layer is equipped with reducing gas circulating cabin, inner layer is equipped with sequentially connected inlet cabin, local pickling cabin, annealing cabin, galvanizing cabin, induction heating cabin and outlet cabin;Local pickling cabin includes roller conveyor, and the upper and lower of roller conveyor are equipped with nozzle mechanical arm, and local pickling cabin bottom is equipped with waste liquid pool;Galvanizing cabin includes galvanizing pool, and galvanizing pool is arranged in galvanizing cabin, and first material guide roller, first limit roller, second limit roller, third limit roller and second material guide roller are sequentially arranged along steel plate conveying path, and with galvanizing pool adaptation, guide steel plate to be immersed, go out with preset angle zinc liquid.This application improves galvanizing efficiency, and improves the corrosion resistance of steel plate.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of steel material processing, and in particular to a device and method for controlling surface defects of an alloyed hot-dip galvanized steel sheet. BACKGROUND

[0002] In the field of research on surface treatment processes of metal materials, hot-dip galvanized steel sheets exhibit more significant corrosion resistance advantages than cold-rolled steel sheets. Based on this characteristic, hot-dip galvanized steel sheets have shown high application value and wide market demand in many key industrial application fields such as automobile manufacturing, household appliances, and modern building construction.

[0003] At present, the market has increasingly high quality requirements for zinc-iron alloyed sheets. The common defects of zinc-iron alloyed sheets are point defects and sheet defects. The point defects are caused by incomplete pickling of the iron oxide on the surface of the steel sheet, resulting in point-like oxides remaining on the surface of the steel sheet, which combine with zinc liquid to form zinc-iron alloy phases, causing surface defects.

[0004] In summary, the current strip steel galvanizing device and method mainly aim to address the non-uniformity of the galvanized layer, the problem of bubble retention during the galvanizing process, and improve the bonding force of the plated layer, and solve the problem of tension relaxation that may occur when the strip steel is pressed into the zinc liquid. In addition, existing technologies (such as patents CN115216607B, CN119703265A, and CN118038178A) also disclose some general strip steel surface defect detection and processing solutions. However, these existing solutions focus on offline or online detection and classification of defects, or focus on preventing defects from occurring by adjusting process parameters throughout the entire process, or focus on cleaning the surface through physical or chemical methods to expose defects. For defects generated in the alloyed hot-dip galvanizing process, which have their unique formation mechanism, there is a lack of effective online, real-time, and closed-loop control means. In particular, how to integrate defect recognition, decision-making, and precise execution into a systematic control device and method is still a difficulty in existing technologies. Based on the above technical problems, the present application proposes a device and method for controlling surface defects of an alloyed hot-dip galvanized steel sheet. SUMMARY

[0005] According to the technical problems of the point defects and the sheet defects of the zinc-iron alloyed steel plate caused by incomplete pickling of the iron oxide on the surface of the steel plate, a surface defect control device and method for the alloyed hot-dip galvanized steel plate are provided.The present application mainly uses the visual detection of the inlet input device to accurately identify the distribution of residual oxides on the surface of the steel plate, the local pickling cabin accurately picks the specific area according to the identification result, the inner layer of the integrated galvanizing device is coordinated, and the outlet output device detects and feeds back the temperature and the surface quality, so as to accurately remove the residual iron oxide on the surface of the steel plate and avoid point defects; by controlling the posture, temperature and other parameters of the steel plate during galvanizing, the generation of sheet defects is inhibited; the whole process monitoring and feedback ensure the stability of the surface quality of the hot-dip galvanized steel plate, and meet the demand of the automobile industry for high-performance galvanized steel plate.

[0006] The technical means adopted by the present application are as follows:

[0007] A surface defect control device for the alloyed hot-dip galvanized steel plate, comprising an inlet input device, an integrated galvanizing device and an outlet output device connected in sequence, the inlet input device inputs the steel plate, and the outlet output device outputs the finished product of the steel plate;

[0008] The integrated galvanizing device is a double-layer structure, the outer layer is provided with a reducing gas circulating cabin, and the inner layer is provided with an inlet cabin, a local pickling cabin, an annealing cabin, a galvanizing cabin, an induction heating cabin and an outlet cabin connected in sequence;

[0009] The local pickling cabin comprises a waste liquid pool, a drum conveying device and a nozzle mechanical arm, the inlet end of the drum conveying device is in communication with the inlet cabin, the outlet end of the drum conveying device is in communication with the inlet end of the annealing cabin, the upper and lower parts of the drum conveying device are provided with the nozzle mechanical arm, and the bottom of the local pickling cabin is provided with the waste liquid pool;

[0010] The galvanizing cabin comprises a zinc liquid pool, a first material guiding roller, a first limiting roller, a second limiting roller, a third limiting roller and a second material guiding roller, the zinc liquid pool is arranged in the galvanizing cabin, the first material guiding roller, the first limiting roller, the second limiting roller, the third limiting roller and the second material guiding roller are arranged along the steel plate conveying path in sequence and are matched with the zinc liquid pool to guide the steel plate to be immersed into and out of the zinc liquid at a preset angle, the inlet end of the galvanizing cabin is in communication with the outlet end of the annealing cabin, and the outlet end of the galvanizing cabin is in communication with the inlet end of the induction heating cabin.

[0011] Further, the induction heating cabin comprises a second transverse induction heater, the second transverse induction heater comprises a first induction coil and a second induction coil, the first induction coil is arranged above and below the steel plate moving path, the second induction coil is arranged on the side of the steel plate moving path, the inlet end of the induction heating cabin is in communication with the outlet end of the galvanizing cabin, and the outlet end of the induction heating cabin is in communication with the outlet cabin.

[0012] Further, the reducing gas circulation cabin comprises a communicating upper reducing gas cabin and a lower reducing gas cabin, the inlet cabin is provided with an inlet gas concentration detector, and the outlet cabin is provided with an outlet gas concentration detector. When the detection values of the inlet gas concentration detector and the outlet gas concentration detector both reach the preset reducing gas concentration requirement, it is determined that the reducing gas concentration in the device meets the standard.

[0013] Further, the annealing cabin comprises a first transverse induction heater, the inlet end of the annealing cabin is communicated with the outlet end of the local pickling cabin, and the outlet end of the annealing cabin is communicated with the inlet end of the galvanizing cabin.

[0014] Further, the inlet input device comprises a vertical range finder, a horizontal range finder and a first camera, the horizontal range finder and the vertical range finder are used to measure the width and thickness data of the steel plate, and the first camera is used to visually detect the steel plate to obtain the residual oxide data on the surface of the steel plate.

[0015] Further, the outlet output device comprises an infrared thermal imager and a second camera, the infrared thermal imager is used to test the temperature detection result of the steel plate product, and the second camera is used to detect the surface defects of the steel plate product.

[0016] A surface defect control method of an alloyed hot galvanized steel plate is realized based on the above-mentioned surface defect control device of the alloyed hot galvanized steel plate, and comprises the following steps:

[0017] S1. The inlet input device visually detects the steel plate to obtain residual oxide data on the surface of the steel plate and thickness and width data of the steel plate, determines whether local pickling is needed based on the residual oxide data on the surface of the steel plate, and determines the local pickling area of the steel plate if local pickling is needed.

[0018] S2. The visually detected steel plate is conveyed to an integrated galvanizing device, the integrated galvanizing device comprises a local pickling cabin, an annealing cabin, a galvanizing cabin and an induction heating cabin connected in sequence, and reducing gas is introduced into the integrated galvanizing device.

[0019] S3. After the concentration of the reducing gas reaches the preset concentration, it is determined whether local pickling is needed based on the result of the visual detection system detecting the residual oxide data on the surface of the steel plate, the local pickling cabin performs local pickling on the visually detected steel plate according to the local pickling area if local pickling is needed, and the locally pickled steel plate is conveyed to the annealing cabin after local pickling; if local pickling is not needed, the steel plate is conveyed to the annealing cabin.

[0020] S4. The steel plate obtained in S3 is sequentially passed through the annealing cabin, the galvanizing cabin and the induction heating cabin to obtain a steel plate product.

[0021] S5. The steel plate product is transmitted to an outlet output device, the outlet output device tests the temperature of the steel plate product, determines whether the surface of the steel plate product reaches a specified temperature and whether the temperature is uniform based on the temperature result, and after determining that the specified temperature is reached and the temperature is uniform, the steel plate product is output.

[0022] Further, when the temperature test result does not reach the temperature range, the heater power of the induction heating cabin is increased;

[0023] The surface of the steel plate product is detected for defects, if the surface of the steel plate product has a flaky white spot defect, the holding time of the steel plate in the induction heating cabin is extended, and if the surface of the steel plate product has a punctate white spot defect, the pickling time of the steel plate in the local pickling cabin is increased.

[0024] Further, the heating method of the induction heating area is:

[0025] A first coil is arranged above and below the galvanized steel plate, a second coil is arranged on the side of the galvanized steel plate, whether the width of the steel plate meets the induction heating range of the first coil is measured, if the induction heating range of the first coil is met, the first coil is started to heat the galvanized steel plate, if the induction heating range of the first coil is not met, the first coil and the second coil are started to heat the galvanized steel plate, so as to ensure that the galvanized steel plate is uniformly heated at each position.

[0026] Further, the outlet output device tests the temperature of the steel plate product, comprising:

[0027] The outlet output device is provided with an infrared thermal imager, the infrared thermal imager tests five equally divided points in the width direction and three equally divided points in the thickness direction of the steel plate product, and obtains the temperature test result of the steel plate product.

[0028] Compared with the prior art, the present application has the following advantages:

[0029] 1. The device of the present application adopts a double-layer structure design as a whole, the outer layer is a reducing gas circulation cabin which provides an oxygen-free environment for the device. The inner part is provided with an inlet cabin, a local pickling cabin, an annealing cabin, a galvanizing cabin, an induction heating cabin and an outlet cabin which are connected with each other to ensure that the strip steel is not oxidized during the galvanizing process.

[0030] 2. The horizontal induction heater of the present application is provided with two sets of upper and lower coils and two sets of left and right heating coils, which can heat the strip steel more uniformly and reduce surface defects caused by uneven heating of the strip steel.

[0031] 3, The present application can be aimed at the problems of galvanized steel strip, timely feedback adjustment, and ensure the follow-up production. For the temperature not reaching the specified temperature range, the control system increases the induction heating power of the follow-up production; for the point-like white spot defects, the control system feedback prolongs the pickling time of the follow-up production process; for the sheet-like white spot, the control system prolongs the induction heating time.

[0032] Based on the above reasons, the present application can be widely popularized in the field of steel material processing and the like. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0034] Figure 1 A flowchart of a surface defect control method of an alloyed hot galvanized steel plate provided by the present application.

[0035] Figure 2 A whole device diagram of the surface defect control device of the alloyed hot galvanized steel plate provided by the present application.

[0036] Figure 3 An internal structure diagram of the integrated galvanizing device provided by the present application.

[0037] Figure 4 An inlet input device schematic diagram provided by the present application.

[0038] Figure 5 An outlet output device schematic diagram provided by the present application.

[0039] Figure 6 A heating structure schematic diagram in the induction heating area provided by the present application.

[0040] Figure 7 A temperature measuring point schematic diagram of the finished steel plate provided by the present application.

[0041] In the figure: 1, inlet input device; 2, outlet output device; 3, waste liquid pool; 4, nozzle mechanical arm; 5, roller conveying device; 6, inlet cabin; 7, inlet gas concentration detector; 8, upper reducing gas cabin; 9, local pickling cabin; 10, annealing cabin; 11, first transverse induction heater; 12, galvanizing cabin; 13, second limiting roller; 14, induction heating cabin; 15, second transverse induction heater; 16, outlet cabin; 17, outlet gas concentration detector; 18, second material guiding roller; 19, third limiting roller; 20, zinc liquid pool; 21, first limiting roller; 22, first material guiding roller; 23, lower reducing gas cabin; 24, first camera; 25, horizontal range finder; 26, infrared thermal imager; 27, vertical range finder; 28, second camera. DETAILED DESCRIPTION

[0042] In order to make the personnel in the technical field better understand the present application scheme, the technical scheme in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by the person skilled in the art without making creative efforts should belong to the protection scope of the present application.

[0043] It should be noted that the terms "first", "second" and the like in the specification and claims of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or a chronological sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0044] As shown in Figure 2 An alloyed hot-dip galvanized steel sheet surface defect control device, comprising an inlet input device 1, an integrated galvanizing device and an outlet output device 2 connected in sequence, the inlet input device 1 inputs the steel sheet, and the outlet output device 2 outputs the finished steel sheet product.

[0045] As shown in Figure 3As shown, the integrated galvanizing device is a double-layer structure, the outer layer is provided with a reducing gas circulating cabin, and the inner layer is provided with an inlet cabin 6, a partial pickling cabin 9, an annealing cabin 10, a galvanizing cabin 12, an induction heating cabin 14 and an outlet cabin 16 connected in sequence. The overall device adopts a closed structure, and reducing gas: 20% H2 and 80% N2 is introduced into the device to prevent the oxidation reaction of the steel plate with oxygen in the air to generate oxides in the subsequent process, affecting the uniformity of the galvanizing of the steel plate.

[0046] The partial pickling cabin 9 includes a waste liquid pool 3, a drum conveying device 5 and a nozzle mechanical arm 4, the inlet end of the drum conveying device 5 is communicated with the inlet cabin 6, the outlet end of the drum conveying device 5 is communicated with the inlet end of the annealing cabin 10, the nozzle mechanical arm 4 is arranged above and below the drum conveying device 5, and the bottom of the partial pickling cabin 9 is provided with the waste liquid pool 3.

[0047] The nozzle mechanical arm 4 sprays dilute hydrochloric acid solution and clean water to remove the oxides on the surface of the steel plate, and after cleaning, the steel plate is conveyed to the annealing cabin 10.

[0048] The galvanizing cabin 12 includes a zinc liquid pool 20, a first material guiding roller 22, a first limiting roller 21, a second limiting roller 13, a third limiting roller 19 and a second material guiding roller 18, the zinc liquid pool 20 is arranged in the galvanizing cabin 12, the first material guiding roller 22, the first limiting roller 21, the second limiting roller 13, the third limiting roller 19 and the second material guiding roller 18 are arranged in sequence along the steel plate conveying path and are matched with the zinc liquid pool 20 to guide the steel plate to be immersed and passed out of the zinc liquid at a preset angle, the inlet end of the galvanizing cabin 12 is communicated with the outlet end of the annealing cabin 10, and the outlet end of the galvanizing cabin 12 is communicated with the inlet end of the induction heating cabin 14.

[0049] Further, the induction heating cabin 14 includes a second transverse induction heater 15, the second transverse induction heater 15 includes a first induction coil and a second induction coil, the first induction coil is arranged above and below the steel plate moving path, and the second induction coil is arranged at the side of the steel plate moving path, the inlet end of the induction heating cabin 14 is communicated with the outlet end of the galvanizing cabin 12, and the outlet end of the induction heating cabin 14 is communicated with the outlet cabin 16.

[0050] Among them, the first induction coil is a rhombic induction coil, and the second induction coil is a rectangular induction coil. In the heating process, the galvanized sheet can be heated to 500-550℃ within 10 seconds, and for the steel plate that is too wide, the rectangular edge coil can be used for heat compensation to make the overall temperature difference of the steel plate less than ±10℃, and the induction heater is provided with 4 groups, the first two groups are responsible for heating the steel strip to a specified temperature, and the last two groups are responsible for heat compensation of the steel strip to prolong the reaction time of the zinc layer and the steel strip.

[0051] Further, the reducing gas circulation cabin comprises the upper reducing gas cabin 8 and the lower reducing gas cabin 23 which are communicated, the inlet cabin 6 is provided with the inlet gas concentration detector 7, and the outlet cabin 16 is provided with the outlet gas concentration detector 17. When the detection values of the inlet gas concentration detector 7 and the outlet gas concentration detector 17 both reach the preset reducing gas concentration requirement, it is determined that the reducing gas concentration in the device meets the standard.

[0052] Further, the annealing cabin 10 comprises the first transverse induction heater 11, the inlet end of the annealing cabin 10 is communicated with the outlet end of the partial pickling cabin 9, and the outlet end of the annealing cabin 10 is communicated with the inlet end of the galvanizing cabin 12.

[0053] As shown in the figure, further, the inlet input device 1 comprises the vertical range finder 27, the horizontal range finder 25 and the first camera 24, the horizontal range finder 25 and the vertical range finder 27 are used for measuring the width and thickness data of the steel plate, and the first camera 24 is used for visually detecting the steel plate to obtain the residual oxide data on the surface of the steel plate. Figure 4

[0054] As shown in the figure, further, the outlet output device 2 comprises the infrared thermal imager 26 and the second camera 28, the infrared thermal imager 26 is used for testing to obtain the temperature detection result of the finished steel plate, and the second camera 28 is used for detecting the surface defects of the finished steel plate. Figure 5

[0055] As shown in the figure, the embodiment of the present application further comprises a kind of alloying hot galvanizing steel plate surface defect control method, is realized based on above-mentioned alloying hot galvanizing steel plate surface defect control device, and step is specifically as follows: Figure 1

[0056] S1. the inlet input device 1 uses high-resolution CCD camera to visually detect the steel plate, obtains the residual oxide data on the surface of the steel plate and the thickness and width data of the steel plate, judges whether it needs partial pickling based on the residual oxide data on the surface of the steel plate, and if it needs partial pickling, determines the area of the steel plate needing partial pickling.

[0057] S2. the steel plate after visual detection is transported to integrated galvanizing device, and the integrated galvanizing device comprises the partial pickling cabin 9, the annealing cabin 10, the galvanizing cabin 12 and the induction heating cabin 14 which are sequentially connected, and reducing gas is introduced into the integrated galvanizing device.

[0058] ​​​S3. After the concentration of the reducing gas reaches the preset concentration, the concentration of the reducing gas reaches the preset concentration, based on the result of whether the steel plate surface residual oxide data detected by the visual detection system needs local pickling, if local pickling is needed, the local pickling area is needed, the local pickling cabin 9 performs local pickling on the steel plate after visual detection, and after local pickling, the steel plate after local pickling is transported to the annealing cabin 10; if local pickling is not needed, the steel plate is transported to the annealing cabin 10.

[0059] S4. The steel plate obtained in S3 is sequentially passed through the annealing cabin 10, the galvanizing cabin 12 and the induction heating cabin 14 to obtain a steel plate finished product.

[0060] S5. The steel plate finished product is transported to the outlet output device 2, the outlet output device 2 tests the temperature of the steel plate finished product, and based on the temperature result, it is judged whether the surface of the steel plate finished product reaches the specified temperature and whether the temperature is uniform, and after it is judged that the specified temperature is reached and the temperature is uniform, the steel plate finished product is output.

[0061] As a preferred mode of the embodiment of the present application, when the temperature test result does not reach the temperature range, the power of the heater of the induction heating cabin 14 is increased. The surface defect of the steel plate finished product is detected, if the steel plate finished product surface appears flaky white spot defect, the holding time of the steel plate in the induction heating cabin 14 is extended, if the steel plate finished product surface appears point white spot defect, the pickling time of the steel plate in the local pickling cabin 9 is increased.

[0062] As a preferred mode of the embodiment of the present application, the heating method of the induction heating area is:

[0063] As shown in Figure 6 , the first coil is arranged above and below the galvanized steel plate, and the second coil is arranged on the side of the galvanized steel plate. It is measured whether the width of the steel plate meets the induction heating range of the first coil. If it meets the induction heating range of the first coil, the first coil is started to heat the galvanized steel plate. If it does not meet the induction heating range of the first coil, the first coil and the second coil are started to heat the galvanized steel plate at the same time to ensure that the galvanized steel plate is evenly heated at each position.

[0064] Specifically, in the induction heating area, the steel plate is transversely inductively heated. If the width of the steel plate is close to the induction heating range of the coil I, scheme one is adopted to heat the steel plate: the first coil (coil I) is started to transversely inductively heat the zinc-sprayed steel plate; if it is found that the width of the steel plate is greater than the induction heating range of the coil I, scheme two is adopted to heat the zinc-sprayed steel plate: the coil I and the second coil (coil II) are started to heat the steel plate at the same time. The role of the coil II is to heat the part that the coil I cannot heat and the edge of the steel plate to ensure that the steel plate surface is evenly heated at each position.

[0065] The rhombic induction coils are arranged on the upper and lower surfaces of the steel plate, and the middle-high frequency power supply is used to realize rapid heating, so as to ensure that the surface temperature of the steel plate is heated to 500-550℃ within 10 seconds, and the heat preservation is performed for 10 seconds, so as to promote the reaction of zinc and the steel plate to form zinc-iron alloy. The rectangular induction coils are additionally arranged in the thickness direction of the steel plate, so as to compensate the non-uniformity of the induction heating in the thickness direction, and ensure that the overall temperature difference of the steel plate is less than ±10℃. The temperature of the zinc-iron alloy steel plate after induction heating is measured, so as to ensure that the zinc and iron react at a suitable temperature.

[0066] As a preferred mode of the embodiment of the present application, as shown in Figure 7 The outlet output device 2 tests the temperature of the steel plate product, and the specific method is as follows:

[0067] The outlet output device 2 is provided with an infrared thermal imager 26, which tests five equally divided points in the width direction and three equally divided points in the thickness direction of the steel plate product, and obtains the temperature detection result of the steel plate product.

[0068] Specifically, after the zinc-plated steel plate is completed induction heating, the zinc-plated steel plate is transmitted to the outlet output device 2 through the device outlet cabin 16 for temperature measurement, the infrared thermal imager 26 collects the temperature of five points (C, D, E, F, G) in the width direction and three points (A, B, C) in the thickness direction in real time, and generates a temperature cloud map of the whole steel plate in real time. Figure 7 If the surface temperature of the zinc-plated steel plate does not reach 500-550℃, the control system feeds back and increases the induction heating power to ensure that the steel plate is heated to the set temperature. When the surface temperature of the zinc-plated steel plate reaches 500-550℃, the surface of the zinc-plated steel plate is detected for defects. If sheet-shaped white spot defects are found, the control system feeds back and reduces the conveying speed of the steel plate to prolong the time of the steel plate in the induction heater. If point-shaped white spots are found, when the zinc layer reacts with the steel plate to form zinc-iron alloy, the degree of zinc-iron alloying at the defect position is lower than that of the surrounding area, so point-shaped white spots are generated. The control system feeds back and prolongs the time of the steel plate for local pickling in the subsequent production.

[0069] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An apparatus for controlling surface defects of an alloyed hot-dip galvanized steel sheet, characterized by, The integrated galvanizing device is of a double-layer structure, an outer layer of which is provided with a reducing gas circulating cabin, and an inner layer of which is provided with an inlet cabin, a local pickling cabin, an annealing cabin, a galvanizing cabin, an induction heating cabin and an outlet cabin connected in sequence. The local pickling cabin comprises a waste liquid pool, a drum conveying device and a nozzle mechanical arm, the inlet end of the drum conveying device is in communication with the inlet cabin, the outlet end of the drum conveying device is in communication with the inlet end of the annealing cabin, the upper and lower parts of the drum conveying device are provided with the nozzle mechanical arm, and the bottom of the local pickling cabin is provided with the waste liquid pool. The galvanizing cabin comprises a zinc liquid pool, a first material guiding roller, a first limiting roller, a second limiting roller, a third limiting roller and a second material guiding roller, the zinc liquid pool is arranged in the galvanizing cabin, the first material guiding roller, the first limiting roller, the second limiting roller, the third limiting roller and the second material guiding roller are arranged along a steel plate conveying path in sequence and are matched with the zinc liquid pool to guide the steel plate to be immersed into and out of the zinc liquid at a preset angle, the inlet end of the galvanizing cabin is in communication with the outlet end of the annealing cabin, and the outlet end of the galvanizing cabin is in communication with the inlet end of the induction heating cabin. The inlet input device comprises a vertical range finder, a horizontal range finder and a first camera, the horizontal range finder and the vertical range finder are used to measure the width and thickness data of the steel plate, and the first camera is used to perform visual detection on the steel plate to obtain the surface residual oxide data of the steel plate. The outlet output device comprises an infrared thermal imager and a second camera, the infrared thermal imager is used to test the temperature detection result of the steel plate product, and the second camera is used to detect the surface defects of the steel plate product. The induction heating cabin comprises a second transverse induction heater, the second transverse induction heater comprises a first induction coil and a second induction coil, the first induction coil is arranged above and below the steel plate moving path, and the second induction coil is arranged on the side of the steel plate moving path, the inlet end of the induction heating cabin is in communication with the outlet end of the galvanizing cabin, and the outlet end of the induction heating cabin is in communication with the outlet cabin.

2. The alloyed hot-dip galvanized steel sheet surface defect control apparatus according to claim 1, characterized by, The reducing gas circulating cabin comprises an upper reducing gas cabin and a lower reducing gas cabin in communication, the inlet cabin is provided with an inlet gas concentration detector, and the outlet cabin is provided with an outlet gas concentration detector.

3. The alloyed hot-dipped galvanized steel sheet surface defect control device according to claim 1, characterized by, The annealing cabin comprises a first transverse induction heater, the inlet end of the annealing cabin is in communication with the outlet end of the local pickling cabin, and the outlet end of the annealing cabin is in communication with the inlet end of the galvanizing cabin.

4. The alloyed hot-dipped galvanized steel sheet surface defect control apparatus according to claim 1, characterized by, The method comprises the following steps:

5. A method for controlling surface defects of an alloyed hot-dip galvanized steel sheet, realized based on the apparatus for controlling surface defects of an alloyed hot-dip galvanized steel sheet according to any one of claims 1 to 4, characterized in that, S1. The inlet input device performs visual detection on the steel plate to obtain the surface residual oxide data and the thickness and width data of the steel plate, determines whether local pickling is needed based on the surface residual oxide data, and determines the area of the steel plate that needs local pickling if local pickling is needed. ​ S2. The steel plate after visual inspection is transported to an integrated galvanizing device, which comprises a local pickling cabin, an annealing cabin, a galvanizing cabin and an induction heating cabin connected in sequence, and reducing gas is introduced into the integrated galvanizing device; S3. After the concentration of the reducing gas reaches the preset concentration, based on the result of whether local pickling is needed, if local pickling is needed, the local pickling cabin performs local pickling on the steel plate after visual inspection according to the area needing local pickling, and after local pickling, the steel plate after local pickling is transported to the annealing cabin; if local pickling is not needed, the steel plate is transported to the annealing cabin; S4. The steel plate obtained in S3 is sequentially passed through the annealing cabin, the galvanizing cabin and the induction heating cabin to obtain a steel plate product; S5. The steel plate product is transported to an outlet output device, the outlet output device tests the temperature of the steel plate product, and based on the temperature result, it is determined whether the surface of the steel plate product reaches a specified temperature and whether the temperature is uniform, and after it is determined that the specified temperature is reached and the temperature is uniform, the steel plate product is output.

6. The alloyed hot-dipped galvanized steel sheet surface defect control method according to claim 5, characterized by, When the temperature test result does not reach the temperature range, the power of the heater of the induction heating cabin in subsequent production is increased; The surface of the steel plate product is detected for defects, if the surface of the steel plate product appears flaky white spot defects, the holding time of the steel plate in the induction heating cabin in subsequent production is extended, and if the surface of the steel plate product appears point-like white spot defects, the pickling time of the steel plate in the local pickling cabin in subsequent production is increased.

7. The method of controlling surface defects of a galvannealed steel sheet according to claim 5, characterized by, The heating method of the induction heating area is: A first coil is arranged above and below the galvanized steel plate, and a second coil is arranged on the side of the galvanized steel plate, the width of the steel plate is measured to determine whether it meets the induction heating range of the first coil, if it meets the induction heating range of the first coil, the first coil is activated to heat the galvanized steel plate, and if it does not meet the induction heating range of the first coil, the first coil and the second coil are activated to heat the galvanized steel plate to ensure that the galvanized steel plate is evenly heated at each position.

8. The method for controlling surface defects of a galvannealed steel sheet according to claim 5, characterized by, The outlet output device tests the temperature of the steel plate product, which includes: The outlet output device is provided with an infrared thermal imager, which tests five equally divided points in the width direction and three equally divided points in the thickness direction of the steel plate product to obtain the temperature test result of the steel plate product.

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