Sampling detection method for zinc plating and aluminum plating production

Abstract

The invention discloses a sampling detection method for zinc plating and aluminum plating production, which comprises the following steps: S1, sampling at regular time: in the continuous production process of a zinc plating or aluminum plating production line, obtaining samples from molten zinc or molten aluminum according to the grade of a produced product and a preset time interval; s2, rapid cooling: carrying out water cooling on the sample obtained in the step S1; s3, sample preparation: fixing the cooled sample through a sample fixer, and grinding an oxide layer on the surface of the sample through grinding equipment; and S4, component detection: detecting the internal analysis surface obtained in the step S3 by adopting a spectrograph, and analyzing the trace alloy element components in the zinc liquid or the aluminum liquid. According to the method, the dynamic change of the variable trace elements in the zinc liquid or the aluminum liquid in the high-speed production process can be tightly tracked, adjustment is carried out according to component deviation before the variable trace elements exceed a process window, and the problems of surface defects and the like caused by component fluctuation are greatly reduced.

Description

Technical Field

[0001] This invention belongs to the field of strip steel processing technology, specifically relating to a sampling and testing method for galvanizing and aluminizing production. Background Technology

[0002] In the field of metal materials manufacturing, galvanizing and aluminizing are key processes widely used in the corrosion protection of steel. Especially for products such as automotive exterior panels and high-end appliance panels, extremely stringent requirements are placed on the surface quality, coating uniformity, and corrosion resistance of the coated sheets. The quality of the coating depends not only on process parameters (such as temperature and speed) but also closely on the composition and stability of trace alloying elements (such as aluminum, magnesium, and antimony) in the molten zinc or aluminum. These trace elements directly affect the fluidity of the plating solution, the adhesion between the coating and the substrate, surface gloss, and the probability of defects (such as incomplete plating, zinc ash, and zinc dross).

[0003] Currently, the industry commonly uses timed sampling combined with spectral analysis to monitor plating solution composition. However, existing conventional testing methods have a series of technical limitations, making it difficult to meet the quality control requirements of high-end product manufacturing:

[0004] First, the sampling interval is unscientific. Traditional methods typically use fixed and relatively long intervals (such as once every 8 hours or per shift) for sampling. However, for high-speed modern galvanizing production lines, the composition of the plating solution, especially easily oxidized and volatile trace alloying elements, changes rapidly during actual production. This fluctuation is particularly pronounced when switching product specifications. This lag in detection fails to reflect the true state of the plating solution in a timely manner, leading to blind spots in process control and easily causing batch-wide quality defects.

[0005] Secondly, the sample preparation method has flaws. Samples taken from the high-temperature plating bath are usually rapidly solidified using water cooling. While this improves sampling efficiency, it leads to the formation of a thick oxide film and contaminants on the sample surface. Direct spectral analysis of this surface yields data that cannot represent the true composition of the sample's interior, resulting in poor accuracy and misleading production adjustments.

[0006] Finally, traditional sample preparation methods are inefficient and inconsistent. To remove the surface oxide layer, operators often use manual grinding or simple tools, making it impossible to precisely control the grinding depth and surface smoothness. This results in rough and uneven analytical surfaces, severely affecting the analytical accuracy and stability of the spectrometer. This interference from human factors makes the detection data unreliable and uncomparable.

[0007] Therefore, there is an urgent need for a sampling and testing method that can achieve high frequency, high precision, and high consistency, so as to quickly and accurately monitor the dynamic changes of plating solution composition, thereby providing reliable data support for the stable production of high-end zinc-plated and aluminum-plated products and effectively improving product quality and yield. Summary of the Invention

[0008] To address the aforementioned shortcomings of existing technologies, a sampling and testing method for zinc plating and aluminum plating production is provided.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A sampling and testing method for use in zinc plating and aluminum plating production includes the following steps:

[0011] S1. Timed sampling: During the continuous production process of galvanizing or aluminizing production line, cylindrical samples are taken from molten zinc or molten aluminum at preset time intervals according to the grade of the product being produced.

[0012] S2. Rapid cooling: The sample obtained in step S1 is water-cooled to rapidly solidify it;

[0013] S3. Sample preparation: The cooled sample is fixed with a sample holder and the surface oxide layer of the sample is ground with a grinding device to expose a smooth and clean internal analytical surface.

[0014] S4. Composition analysis: The internal analysis surface obtained in step S3 is analyzed using a spectrometer to determine the trace alloying element composition in the zinc or aluminum liquid.

[0015] Preferably, in step S1, the preset time interval is once every 4 hours when producing ordinary products, and once every 2 hours when producing high-grade sheet products such as automotive outer panels.

[0016] Preferably, the cylindrical sample has a diameter of 40 mm and a thickness of 30 mm.

[0017] Preferably, in step S3, the specific method of the grinding process is to fix the sample and expose 10mm of the end to be ground, and then use a grinding device to remove at least 3mm of thickness from the surface.

[0018] Preferably, the sample holder includes a fixing frame, a support frame in the middle of the fixing frame, a connecting rod rotatably mounted on the support frame, a fixing element at one end of the connecting rod to fix the sample, and an adjusting screw at the other end of the connecting rod that can be adjusted up and down to fix the fixing element.

[0019] With the above structural design, the sample can be mounted by adjusting the height of the fixing component, and the bottom of the adjusting screw can be pressed against the fixing frame by adjusting the height of the screw, thereby fixing the sample. Then, the sample can be polished by the polishing equipment. The fixture has a simple structure, strong stability and simple operation.

[0020] Preferably, the fixing member adopts an inverted "V" shaped structure to hold and fix the cylindrical sample, and the inner side wall of the fixing member is provided with anti-slip texture.

[0021] With the above structural design, the fastener adopts an inverted "V" shape, which makes it easy to fix circular samples of different sizes. At the same time, the anti-slip texture design on the inner side can ensure the stability during fixation.

[0022] Preferably, the top of the fixing member is provided with a mounting screw, and the connecting rod is provided with a corresponding first sleeve. The fixing member is movably installed in the first sleeve by the mounting screw, and the other end of the mounting screw is limited by a nut.

[0023] With the above structural design, the fixing component is in a movable state, which can play an adaptive adjustment role when fixing the sample.

[0024] Preferably, the connecting rod is provided with a second sleeve in the middle, and the connecting rod is rotatably connected to the support frame through the second sleeve.

[0025] The above structural design ensures that the two ends of the connecting rod can be adjusted in height with the second sleeve position as the fulcrum, so as to facilitate the installation and fixation of the sample.

[0026] Preferably, an adjusting nut is welded to the end of the connecting rod, the adjusting screw is mounted on the adjusting nut, and the upper end of the adjusting screw is provided with a rotating handle.

[0027] With the above structural design, the sample on the other side can be fixed by adjusting the up and down position of the adjusting nut and using the lever principle.

[0028] Preferably, the lower end of the fixing frame is provided with a support rod and a base.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. This invention implements a differentiated, high-frequency, timed sampling strategy based on product grade, which can closely track the dynamic changes of volatile trace elements in molten zinc or aluminum during high-speed production. This allows operators to promptly detect compositional deviations and make adjustments before they exceed the process window, greatly reducing surface defects and other problems caused by compositional fluctuations. It is particularly suitable for the production of products with extremely high requirements for plate surface quality, effectively ensuring the stability and consistency of product quality.

[0031] 2. In this invention, samples with surface oxide media generated after water cooling undergo forced grinding, thoroughly removing the oxide and contamination layers and exposing a pure, uniform internal metal structure. Combined with spectroscopic analysis, the final compositional data accurately reflects the microscopic composition of the plating solution, rather than erroneous information masked by surface oxides. This provides an extremely accurate data foundation for process adjustments, avoiding misjudgments and resource waste caused by incorrect data.

[0032] 3. The connecting rod of the sample holder of the present invention uses the lever principle, with the middle as the fulcrum, to adjust the height of the adjusting nut at one end, so that the fixing part at the other end can install and fix the sample. This structure can quickly and efficiently fix the sample, and has strong stability, which facilitates sample grinding and subsequent alloy composition detection. Attached Figure Description

[0033] Figure 1 This is a process flow diagram of the present invention;

[0034] Figure 2 This is a schematic diagram of the sample holder in this invention.

[0035] In the picture:

[0036] 1. Fixing frame; 2. Support frame; 3. Connecting rod; 4. Fixing component; 5. Adjusting screw; 6. Mounting screw; 7. First sleeve; 8. Second sleeve; 9. Adjusting nut; 10. Rotating handle; 11. Support rod; 12. Base. Detailed Implementation

[0037] To illustrate the technical content, structural features, objectives, and effects of the present invention in detail, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0038] The technical solution of the present invention will now be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0039] Please see Figure 1 A sampling and testing method for use in zinc plating and aluminum plating production includes the following steps:

[0040] S1. Timed Sampling: During continuous production on the galvanizing or aluminizing production line, cylindrical samples are taken from the molten zinc or aluminum at preset time intervals, depending on the grade of the product being produced. The preset time interval is once every 4 hours for producing ordinary products and once every 2 hours for producing high-grade sheet metal products such as automotive exterior panels. The cylindrical samples have a diameter of 40mm and a thickness of 30mm.

[0041] S2. Rapid cooling: The sample obtained in step S1 is water-cooled to rapidly solidify it;

[0042] S3. Sample preparation: The cooled sample is fixed by a sample holder, and the surface oxide layer of the sample is ground by a grinding device to expose a flat and smooth internal analytical surface; wherein, the specific method of the grinding process is to fix the sample and expose 10 mm of the end to be ground, and then use a grinding device to remove at least 3 mm of thickness from the surface.

[0043] S4. Composition analysis: The internal analysis surface obtained in step S3 is analyzed using a spectrometer to determine the trace alloying element composition in the zinc or aluminum liquid.

[0044] Please see Figure 2 The sample holder includes a fixing frame 1, a support frame 2 in the middle of the fixing frame 1, a connecting rod 3 rotatably mounted on the support frame 2, a fixing member 4 at one end of the connecting rod 3 to fix the sample, and an adjusting screw 5 at the other end of the connecting rod 3 that can be adjusted up and down to fix the fixing member 4.

[0045] The fixing component 4 uses an inverted "V" shaped structure to hold and fix the cylindrical sample, and the inner side wall of the fixing component 4 is provided with anti-slip texture. The fixing component 4 is made of cast iron. The top of the fixing component 4 is provided with a mounting screw 6, and the connecting rod 3 is provided with a corresponding first sleeve 7. The fixing component 4 is movably installed in the first sleeve 7 by the mounting screw 6, and the other end of the mounting screw 6 is limited by a nut. The protruding end of the mounting screw 6 is welded to the fixing component 4, and the screw part is spaced a certain distance from the top of the fixing component 4 to facilitate the installation of the fixing component 4 in the first sleeve 7.

[0046] Furthermore, a second sleeve 8 is provided in the middle of the connecting rod 3, which is fixed by welding. The connecting rod 3 is rotatably connected to the support frame 2 through the second sleeve 8. An adjusting nut 9 is welded to the end of the connecting rod 3, and an adjusting screw 5 is mounted on the adjusting nut 9. A rotating handle 10 is provided at the upper end of the adjusting screw 5.

[0047] Furthermore, the lower end of the fixing frame 1 is provided with a support rod 11 and a base 12.

[0048] When using the sample holder of the present invention:

[0049] First, rotate the adjusting screw 5 upwards to provide sufficient space at the other end of the connecting rod 3 for sample installation. Then, using the position of the second sleeve 8 as a fulcrum, lift one end of the fixing member 4, place the cylindrical sample on the fixing frame 1, and secure it with the fixing member 4. After adjusting the position of the fixing member 4 and the sample, rotate the adjusting screw 5 at the other end of the connecting rod 3 downwards so that the lower end of the adjusting screw 5 abuts against the fixing frame 1, thus fixing the sample at the other end. The next grinding process can then be performed. After grinding, the composition of the ground surface is detected using a spectrometer. Therefore, the sample holder of this invention is easy to operate, can be manufactured using waste materials, has low cost, and provides strong stability, making it suitable for widespread application.

[0050] Based on the disclosure and teachings of the foregoing specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the present invention should also fall within the protection scope of the claims of the present invention. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on the present invention.

Claims

1. A sampling and testing method for use in zinc plating and aluminum plating production, characterized in that, Includes the following steps: S1. Timed sampling: During the continuous production process of galvanizing or aluminizing production line, cylindrical samples are taken from molten zinc or molten aluminum at preset time intervals according to the grade of the product being produced. S2. Rapid cooling: The sample obtained in step S1 is water-cooled to rapidly solidify it; S3. Sample preparation: The cooled sample is fixed with a sample holder and the surface oxide layer of the sample is ground with a grinding device to expose a smooth and clean internal analytical surface. S4. Composition analysis: The internal analysis surface obtained in step S3 is analyzed using a spectrometer to determine the trace alloying element composition in the zinc or aluminum liquid.

2. The sampling and testing method for galvanizing and aluminizing production as described in claim 1, characterized in that, In step S1, the preset time interval is once every 4 hours when producing ordinary products, and once every 2 hours when producing high-grade sheet products such as automotive outer panels.

3. The sampling and testing method for galvanizing and aluminizing production as described in claim 1, characterized in that, The cylindrical sample has a diameter of 40 mm and a thickness of 30 mm.

4. The sampling and testing method for galvanizing and aluminizing production as described in claim 1, characterized in that, In step S3, the specific method of the grinding process is to fix the sample and expose 10mm of the end to be ground, and then use a grinding device to remove at least 3mm of thickness from the surface.

5. The sampling and testing method for galvanizing and aluminizing production as described in claim 1, characterized in that, The sample holder includes a fixing frame (1), a support frame (2) is provided in the middle of the fixing frame (1), a connecting rod (3) is rotatably provided on the support frame (2), a fixing part (4) is provided at one end of the connecting rod (3) to fix the sample, and an adjusting screw (5) that can be adjusted up and down to fix the fixing part (4) is provided at the other end of the connecting rod (3).

6. The sampling and testing method for galvanizing and aluminizing production as described in claim 5, characterized in that, The fixing component (4) adopts an inverted "V" shaped structure to hold and fix the cylindrical sample, and the inner side wall of the fixing component (4) is provided with anti-slip texture.

7. A sampling and testing method for galvanizing and aluminizing production as described in claim 5 or 6, characterized in that, The top of the fixing member (4) is provided with a mounting screw (6), and the connecting rod (3) is provided with a first sleeve (7). The fixing member (4) is movably installed in the first sleeve (7) by the mounting screw (6), and the other end of the mounting screw (6) is limited by a nut.

8. The sampling and testing method for galvanizing and aluminizing production as described in claim 5, characterized in that, The connecting rod (3) is provided with a second sleeve (8) in the middle, and the connecting rod (3) is rotatably connected to the support frame (2) through the second sleeve (8); an adjusting nut (9) is welded to the end of the connecting rod (3), and an adjusting screw (5) is installed on the adjusting nut (9), and a rotating handle (10) is provided at the upper end of the adjusting screw (5).

9. A sampling and testing method for galvanizing and aluminizing production as described in claim 5, characterized in that, The lower end of the fixed frame (1) is provided with a support rod (11) and a base (12).

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