A method for rapidly detecting contents of Zn, Al and Si elements in zinc-aluminum coating

Abstract

The application relates to the technical field of zinc-aluminum coating detection, in particular to a method for rapidly detecting the contents of Zn, Al and Si elements in a zinc-aluminum coating; the method comprises the following steps: ultrasonic cleaning of the zinc-aluminum coating to be detected to obtain a pretreated sample; glow surface analysis of the pretreated sample by using a glow spectrum method, drawing of a horizontal and vertical coordinate graph, and obtaining of an Fe-h curve graph, a Zn-h curve graph, an Al-h curve graph and a Si-h curve graph; according to the curve graphs, the total mass of Zn, Al and Si is respectively calculated; the thickness of the zinc-aluminum coating to be detected is calculated by taking the Fe-h curve graph as a standard curve; according to the curve graphs and the thickness of the zinc-aluminum coating to be detected, the average mass of Zn, Al and Si is respectively obtained; and according to the average mass and the total mass, the average mass fraction of Zn, Al and Si is obtained. The method can avoid the substrate effect of the zinc-aluminum coating in the detection process, so that the accuracy of the zinc-aluminum coating detection is improved.

Description

Technical Field

[0001] This application relates to the field of zinc-aluminum coating detection technology, and in particular to a method for rapidly detecting the content of Zn, Al, and Si elements in zinc-aluminum coatings. Background Technology

[0002] Zinc-aluminum coating is a silver or silver-gray corrosion-resistant inorganic coating formed by applying water-based chromium-free zinc-aluminum paint to the surface of steel parts or components through dipping, brushing, or spraying, followed by baking. Currently, zinc-aluminum coatings generally contain zinc flakes, aluminum flakes, curing agents, and thickeners. For determining the content of various elements in cured zinc-aluminum coatings, the current method is usually based on chemical dissolution, using inorganic acids to dissolve and leach the coating to prepare a test solution. Then, inductively coupled plasma atomic absorption spectrometry (ICP), mass spectrometry (MS), or atomic absorption spectrometry (AAS) is used to measure the content of the zinc-aluminum coating in the test solution. Alternatively, a physical peeling method can be used, where the zinc-aluminum coating is scraped off the surface of steel parts or components to obtain scraped powder. This scraped powder is then dissolved in inorganic acids to prepare a test solution, which is then measured using ICP, MS, or AAS to obtain the corresponding spectral data.

[0003] However, regardless of whether the test solution is formed based on chemical principles or physical sampling methods, it is inevitable that some substrate will be incorporated. These substrates will exhibit substrate effect during the detection stage, resulting in a large error in the final detection result. Summary of the Invention

[0004] This application provides a method for rapidly detecting the content of Zn, Al, and Si elements in zinc-aluminum coatings, in order to solve the following technical problem: how to improve the accuracy of component detection in zinc-aluminum coatings.

[0005] In a first aspect, this application provides a method for rapidly detecting the content of Zn, Al, and Si elements in a zinc-aluminum coating, the method comprising:

[0006] The zinc-aluminum coating to be tested was ultrasonically cleaned to obtain a pretreated sample;

[0007] The pretreated sample was subjected to glow discharge surface analysis using glow discharge spectroscopy to determine the quantitative relationship between the Fe, Zn, Al and Si contents in the zinc-aluminum coating and the depth of the zinc-aluminum coating, and the first, second, third and fourth variation curves of Fe, Zn, Al and Si contents with the depth of the zinc-aluminum coating were obtained respectively.

[0008] Based on the second, third, and fourth variation curves, calculate the total mass data of Zn, Al, and Si in the zinc-aluminum coating to be tested, respectively.

[0009] The thickness of the zinc-aluminum coating is calculated based on the first curve.

[0010] Based on the second variation curve, the third variation curve, the fourth variation curve, and the zinc-aluminum coating thickness, the average mass data of Zn, Al, and Si in the zinc-aluminum coating to be tested are calculated respectively.

[0011] The average mass fractions of Zn, Al, and Si in the zinc-aluminum coating to be tested are obtained based on the average mass data of Zn, Al, and Si in the zinc-aluminum coating to be tested and the total mass data of Zn, Al, and Si in the zinc-aluminum coating to be tested, respectively.

[0012] Optionally, the step of calculating the thickness of the zinc-aluminum coating to be tested using the Fe-h curve as a standard curve includes the following steps:

[0013] Using the Fe-h curve as a standard curve, the zinc-aluminum coating depth and the iron mass fraction within the zinc-aluminum coating of the Fe-h curve were determined respectively.

[0014] When the iron mass fraction in the zinc-aluminum coating of the Fe-h curve is ≤84%, the depth of the zinc-aluminum coating in the Fe-h curve is determined as the thickness of the zinc-aluminum coating.

[0015] Optionally, the glow discharge surface analysis includes a vacuuming stage, a discharge stage, a rinsing stage, and a single integration stage. The vacuuming time is 35s to 45s, the voltage of the discharge stage is 995V to 1005V, the current of the discharge stage is 5mA to 15mA, the rinsing time is 10s to 20s, and the single integration stage time is 65ms to 75ms.

[0016] Optionally, the excitation time for the glow discharge surface analysis is ≥180s.

[0017] Optionally, the step of ultrasonically cleaning the zinc-aluminum coating to be tested to obtain a pretreated sample includes the following steps:

[0018] The zinc-aluminum coating to be tested was ultrasonically cleaned using an organic solvent, followed by hot air drying to obtain a pretreated sample.

[0019] Optionally, the ultrasonic cleaning frequency is 80Hz to 90Hz, the ultrasonic cleaning time is 3min to 5min, and the ultrasonic cleaning temperature is 20℃ to 25℃.

[0020] Optionally, the temperature of the hot air drying is 60℃~90℃.

[0021] Optionally, the step of calculating the total mass of Zn, Al, and Si in the zinc-aluminum coating to be tested based on the Zn-h curve, the Al-h curve, and the Si-h curve respectively includes the following steps:

[0022] The masses of Zn, Al, and Si in the Zn-h curve, Al-h curve, and Si-h curve are integrated with respect to the coating depth of the zinc-aluminum coating to be tested, respectively, to calculate the total mass of Zn, Al, and Si in the zinc-aluminum coating to be tested.

[0023] Optionally, the step of calculating the average mass of Zn, Al, and Si in the zinc-aluminum coating to be tested based on the Zn-h curve, the Al-h curve, the Si-h curve, and the thickness of the zinc-aluminum coating to be tested, respectively, includes the following steps:

[0024] The masses of Zn, Al, and Si in the Zn-h curve, Al-h curve, and Si-h curve are integrated with respect to the thickness of the zinc-aluminum coating or the time of the glow discharge surface analysis, respectively, to obtain the mass of Zn, the mass of Al, and the mass of Si in the zinc-aluminum coating to be tested.

[0025] The average mass of Zn, Al, and Si in the zinc-aluminum coating to be tested are respectively used as the numerators, and the total mass of Zn, Al, and Si in the zinc-aluminum coating to be tested is used as the denominator to obtain the average mass of Zn, the average mass of Al, and the average mass of Si in the zinc-aluminum coating to be tested.

[0026] Optionally, the method further includes:

[0027] The standard sample is surface treated to obtain a pretreated standard sample;

[0028] The pretreated standard samples were subjected to glow discharge surface analysis to obtain standard variation curves;

[0029] The standard variation curve is corrected based on the difference between sputtering rate and relative sputtering rate to obtain a corrected curve;

[0030] The parameters for the glow surface analysis are optimized based on the calibration curve.

[0031] The technical solutions provided in this application have the following advantages compared with the prior art:

[0032] This application provides a method for rapidly detecting the content of Zn, Al, and Si elements in a zinc-aluminum coating. The method includes: ultrasonically cleaning the zinc-aluminum coating to be tested to obtain a pretreated sample.

[0033] The pretreated sample was subjected to glow discharge spectroscopy for surface analysis to determine the relationship between the mass of Fe, Zn, Al, and Si in the zinc-aluminum coating and the coating depth h of the zinc-aluminum coating, layer by layer. Fe-h, Zn-h, Al-h, and Si-h curves were obtained by plotting axon and yon axis graphs, respectively. Based on the Zn-h, Al-h, and Si-h curves, the total mass of Zn, Al, and Si in the zinc-aluminum coating was calculated. The thickness of the zinc-aluminum coating was calculated using the Fe-h curve as a standard curve. The average mass of Zn, Al, and Si in the zinc-aluminum coating was calculated based on the Zn-h, Al-h, and Si-h curves and the thickness of the zinc-aluminum coating. This method uses glow discharge spectroscopy to excite the pretreated sample layer by layer, accurately obtaining the quantitative relationship between the mass of Fe, Zn, Al, and Si in each layer of the zinc-aluminum coating and the depth of the coating: Fe-h curves, Zn-h curves, Al-h curves, and Si-h curves. Using the Fe-h curve as a reference, the thickness of the zinc-aluminum coating can be accurately determined. Combining the thickness of the zinc-aluminum coating with the Fe-h, Zn-h, Al-h, and Si-h curves, the average mass of Zn, Al, and Si in the zinc-aluminum coating can be accurately obtained. Compared with traditional methods... The sampling method employs chemical dissolution and physical stripping, which eliminates the need for destructive treatment of the zinc-aluminum coating, thus avoiding substrate effects during detection and improving the accuracy of zinc-aluminum coating analysis. Furthermore, by using the quantitative relationship between Fe content and coating depth within the zinc-aluminum coating as a benchmark, the risk of interference from the relatively reactive metallic structures formed by Zn and Al within the coating on the glow discharge surface analysis process can be reduced, allowing for accurate determination of the coating thickness. This, in turn, enables accurate determination of the average mass fractions of Zn, Al, and Si in the tested zinc-aluminum coating, further improving the accuracy of glow discharge surface analysis. Attached Figure Description

[0034] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0035] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This application provides a schematic flowchart of a method for rapidly detecting the content of Zn, Al, and Si elements in a zinc-aluminum coating.

[0037] Figure 2 A detailed flowchart illustrating a method for rapidly detecting the content of Zn, Al, and Si elements in zinc-aluminum coatings, provided in this application embodiment;

[0038] Figure 3 This is a graph showing the quantitative relationship between the chemical composition content and the depth of the zinc-aluminum coating under test in the glow discharge surface analysis of the zinc-aluminum coating provided in Example 1 of this application. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0040] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range; for example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range such as 1, 2, 3, 4, 5, and 6, regardless of the range; in addition, whenever a numerical range is indicated herein, it means including any referenced number (fraction or integer) within the indicated range.

[0041] In this document, terms such as “comprising” mean “including but not limited to”. Relational terms such as “first” and “second” are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Unless otherwise specified, all raw materials, reagents, instruments, and equipment used in this application are commercially available or can be prepared by existing methods.

[0042] It should be noted that, regarding the chemically based dissolution methods described in the background section, the inventors have found the following drawbacks:

[0043] (1) It is necessary to study the preparation of the etchant for dissolving the coating first. In addition, when the etchant is used to dissolve the coating, if the etching time is not properly controlled or the etchant is not properly selected, some of the substrate will be dissolved. These dissolved substrates will cause quality errors in the substrate and ultimately lead to analytical errors. (2) The coating dissolution process is complex and the analysis cycle is lengthy. (3) For wet chemical analysis methods such as ICP and AAS, the matrix effect is significant. Therefore, matrix matching and other means are usually required to eliminate interference, which increases the overall complexity of the method and consumes a lot of chemical reagents.

[0044] Regarding the physical stripping sampling method described in the background section, the inventors have discovered the following drawbacks of this technique:

[0045] (1) Zinc-aluminum coatings are generally very thin, and the powder scraped off with a scraper is very light. A sufficient number of samples with zinc-aluminum coatings on the surface need to be scraped off to meet the minimum quality requirements for wet chemical testing, which is a lot of work. (2) Using a scraper to scrape off the substrate can easily introduce impurities into the subsequent testing process. (3) The scraper is relatively sharp, which increases the risk of injury to the test personnel during the use of the scraper.

[0046] Figure 1 This is a flowchart illustrating a method for XX according to some embodiments of this application;

[0047] like Figure 1 As shown in the embodiments of this application, a method for rapidly detecting the content of Zn, Al, and Si elements in a zinc-aluminum coating is provided. The method includes:

[0048] S1. The zinc-aluminum coating to be tested is ultrasonically cleaned to obtain a pretreated sample;

[0049] S2. The pretreated sample is subjected to glow discharge surface analysis using glow discharge spectroscopy to determine the relationship between the mass of Fe, Zn, Al and Si in the zinc-aluminum coating to be tested and the coating depth h of the zinc-aluminum coating to be tested, layer by layer. By plotting the horizontal and vertical axis graphs, Fe-h curves, Zn-h curves, Al-h curves and Si-h curves are obtained respectively.

[0050] S3. Calculate the total mass of Zn, Al, and Si in the zinc-aluminum coating to be tested based on the Zn-h curve, the Al-h curve, and the Si-h curve, respectively.

[0051] S4. Using the Fe-h curve as the standard curve, calculate the thickness of the zinc-aluminum coating to be tested;

[0052] S5. Based on the Zn-h curve, the Al-h curve, the Si-h curve, and the thickness of the zinc-aluminum coating to be tested, calculate the average mass of Zn, Al, and Si in the zinc-aluminum coating to be tested, respectively.

[0053] S6. Based on the average mass of Zn, Al and Si in the zinc-aluminum coating to be tested and the total mass of Zn, Al and Si in the zinc-aluminum coating to be tested, the average mass fraction of Zn, Al and Si in the zinc-aluminum coating to be tested is obtained respectively.

[0054] It should be noted that this glow discharge surface analysis generally uses a layer-by-layer excitation mode. The spectral data after layer-by-layer excitation can be processed by the built-in processor of the glow discharge spectrometer to obtain the content of Zn, Al and Si in each layer of the zinc-aluminum coating to be tested.

[0055] It should be noted that the substrate of the zinc-aluminum coating to be tested is generally a steel substrate.

[0056] It should be noted that the glow discharge surface analysis is terminated when the data obtained from the layer-by-layer excitation detection is consistent with the chemical composition data of the matrix.

[0057] In some optional embodiments, the step of calculating the thickness of the zinc-aluminum coating to be tested using the Fe-h curve as a standard curve includes the following steps:

[0058] S401. Using the Fe-h curve as a standard curve, determine the zinc-aluminum coating depth and the iron mass fraction within the zinc-aluminum coating of the Fe-h curve respectively;

[0059] S402. When the iron mass fraction in the zinc-aluminum coating of the Fe-h curve is ≤84%, the depth of the zinc-aluminum coating of the Fe-h curve is determined as the thickness of the zinc-aluminum coating.

[0060] In these embodiments, the Fe-h curve is used as the reference curve and the standard curve is defined as the thickness of the zinc-aluminum coating to be tested when the iron mass fraction in the zinc-aluminum coating is ≤84% according to the Fe-h curve. This can reduce the risk of interference from the relatively active metal structure formed by Zn and Al in the zinc-aluminum coating to the glow discharge surface analysis process, so as to accurately obtain the thickness data of the zinc-aluminum coating to be tested.

[0061] In some optional embodiments, the glow discharge surface analysis includes a vacuuming phase, a discharge phase, a rinsing phase, and a single integration phase. The vacuuming time is 35s to 45s, the voltage of the discharge phase is 995V to 1005V, the current of the discharge phase is 5mA to 15mA, the rinsing time is 10s to 20s, and the single integration phase time is 65ms to 75ms.

[0062] In these embodiments, glow discharge surface analysis may include a vacuuming stage, a discharge stage, a rinsing stage, and a single integration stage. The vacuuming time may be 35s to 45s, the discharge stage voltage may be 995V to 1005V, the discharge stage current may be 5mA to 15mA, the rinsing stage time may be 10s to 20s, and the single integration stage time may be 65ms to 75ms. This allows the glow discharge surface analysis to proceed fully, accurately obtaining the Fe-h curves, Zn-h curves, Al-h curves, and Si-h curves showing the changes in the mass of Fe, Zn, Al, and Si as a function of the depth of the zinc-aluminum coating under test. This allows for the accurate determination of the average mass fraction of Zn, Al, and Si in the zinc-aluminum coating under test, thereby improving the accuracy of glow discharge surface analysis.

[0063] The vacuuming time can be 35s, 36s, 37s, 38s, 39s, 40s, 41s, 42s, 43s, 44s or 45s.

[0064] The voltage of this discharge section can be 995V, 996V, 997V, 998V, 999V, 1000V, 1001V, 1002V, 1003V, 1004V or 1005V.

[0065] The current in this discharge section can be 5mA, 6mA, 7mA, 8mA, 9mA, 10mA, 11mA, 11mA, 12mA, 13mA, 14mA or 15mA.

[0066] The rinsing time is 10s, 11s, 12s, 13s, 14s, 15s, 16s, 17s, 18s, 19s, or 20s.

[0067] The time for a single integration segment can be 65ms, 66ms, 67ms, 68ms, 69ms, 70ms, 71ms, 72ms, 73ms, 74ms, or 75ms.

[0068] In some optional embodiments, the excitation time for the glow discharge surface analysis is ≥180 s;

[0069] In these embodiments, the excitation time for glow discharge surface analysis can be ≥180s, which allows sufficient time for the analysis to accurately obtain the Fe-h curves, Zn-h curves, Al-h curves, and Si-h curves showing the changes in the mass of Fe, Zn, Al, and Si as a function of the depth of the zinc-aluminum coating under test. This allows for the accurate determination of the average mass fractions of Zn, Al, and Si in the zinc-aluminum coating under test, thereby improving the accuracy of glow discharge surface analysis.

[0070] In some optional embodiments, the step of ultrasonically cleaning the zinc-aluminum coating to be tested to obtain a pretreated sample includes the following steps:

[0071] S111. The zinc-aluminum coating to be tested is ultrasonically cleaned using an organic solvent and then dried with hot air to obtain a pretreated sample;

[0072] In these embodiments, introducing hot air drying after ultrasonic cleaning can remove organic solutions from the surface of the zinc-aluminum coating to be tested, thereby obtaining a pure pretreated sample.

[0073] It should be noted that this hot air drying can be performed using a hot air blower.

[0074] In some optional embodiments, the ultrasonic cleaning frequency is 80Hz to 90Hz, the ultrasonic cleaning time is 3min to 5min, and the ultrasonic cleaning temperature is 20℃ to 25℃.

[0075] In these embodiments, the ultrasonic cleaning frequency can be 80Hz to 90Hz, the ultrasonic cleaning time can be 3min to 5min, and the ultrasonic cleaning temperature can be 20℃ to 25℃. Ultrasonic cleaning can effectively remove grease, organic contaminants, and particulate matter from the surface of the zinc-aluminum coating to be tested, thereby obtaining a pure pretreated sample.

[0076] The ultrasonic cleaning frequency can be 80Hz, 81Hz, 82Hz, 83Hz, 84Hz, 85Hz, 86Hz, 87Hz, 88Hz, 89Hz or 90Hz.

[0077] The ultrasonic cleaning time can be 3 minutes, 4 minutes, or 5 minutes.

[0078] The temperature for ultrasonic cleaning can be 20℃, 21℃, 22℃, 23℃, 24℃ or 25℃.

[0079] In some optional embodiments, the temperature of the hot air drying is 60°C to 90°C;

[0080] In these embodiments, the temperature of hot air drying can be 60°C to 90°C. Hot air drying can effectively remove organic solutions from the surface of the zinc-aluminum coating to be tested, thereby obtaining a pure pretreated sample.

[0081] The temperature for hot air drying can be 60℃, 65℃, 70℃, 75℃, 80℃, 85℃ or 90℃.

[0082] In some optional embodiments, the step of calculating the total mass of Zn, Al, and Si in the zinc-aluminum coating to be tested based on the Zn-h curve, the Al-h curve, and the Si-h curve respectively includes the following steps:

[0083] S301. Integrate the masses of Zn, Al, and Si in the Zn-h curve, Al-h curve, and Si-h curve respectively with respect to the coating depth of the zinc-aluminum coating to be tested, so as to calculate the total mass of Zn, Al, and Si in the zinc-aluminum coating to be tested;

[0084] In these embodiments, the relationship between the mass of Zn, Al and Si in the Zn-h curve, Al-h curve and Si-h curve is integrated to calculate the total mass of Zn, Al and Si in the zinc-aluminum coating to be tested.

[0085] In some optional embodiments, the step of calculating the average mass of Zn, Al, and Si in the zinc-aluminum coating to be tested based on the Zn-h curve, the Al-h curve, the Si-h curve, and the thickness of the zinc-aluminum coating to be tested, respectively, includes the following steps:

[0086] S501. Integrate the Zn, Al, and Si masses in the Zn-h curve, Al-h curve, and Si-h curve with respect to the thickness of the zinc-aluminum coating or the time of the glow discharge surface analysis, respectively, to obtain the mass of Zn, the mass of Al, and the mass of Si in the zinc-aluminum coating to be tested.

[0087] S502. Take the mass of Zn, the mass of Al, and the mass of Si in the zinc-aluminum coating to be tested as the numerators, and the total mass of Zn, Al, and Si in the zinc-aluminum coating to be tested as the denominator, respectively, to obtain the average mass of Zn, the average mass of Al, and the average mass of Si in the zinc-aluminum coating to be tested;

[0088] In these embodiments, the masses of Zn, Al, and Si in the Zn-h, Al-h, and Si-h curves are first integrated for the thickness of the zinc-aluminum coating to be tested or the time of glow discharge surface analysis, respectively. This allows for the accurate determination of the mass of Zn, the mass of Al, and the mass of Si in the zinc-aluminum coating to be tested. Then, these masses and the total mass of Zn, Al, and Si in the zinc-aluminum coating to be tested are analyzed to accurately determine the average mass of Zn, the average mass of Al, and the average mass of Si in the zinc-aluminum coating to be tested.

[0089] In some optional implementations, the method further includes:

[0090] S101. Perform surface treatment on the standard sample to obtain a pretreated standard sample;

[0091] S102. Perform glow discharge surface analysis on the pretreated standard sample to obtain a standard variation curve;

[0092] S103. The standard variation curve is corrected based on the difference between sputtering rate and relative sputtering rate to obtain a corrected curve;

[0093] S104. Optimize the parameters of the glow discharge surface analysis based on the calibration curve;

[0094] In these embodiments, the standard variation curve of the glow discharge spectrometer can be obtained by incorporating data such as the pretreatment of standard samples and glow discharge surface analysis into the method. Then, the standard variation curve is corrected based on the difference between sputtering rate and relative sputtering rate, so that the calibration curve for the glow discharge spectrometer can be accurately obtained. Finally, the parameters used in the glow discharge surface analysis process of the glow discharge spectrometer are optimized by using the obtained calibration curve, thereby improving the accuracy of subsequent detection of zinc-aluminum coated samples.

[0095] The present application is further illustrated below with reference to specific embodiments. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to industry standards; if no corresponding industry standard exists, they are performed according to general international standards, conventional conditions, or conditions recommended by the manufacturer.

[0096] Example 1

[0097] like Figure 1 As shown in the embodiments of this application, a method for rapidly detecting the content of Zn, Al, and Si elements in zinc-aluminum coatings is provided, including the following steps:

[0098] 1. Establish a method for analyzing the glow discharge surface of zinc-aluminum coatings, including setting optimal parameters and selecting the best analytical spectral lines.

[0099] (1) Setting the optimal working parameters of the glow discharge spectrometer: Based on the analysis of Zn, Al and Si spectra, the optimal instrument parameters for glow discharge surface analysis are shown in Table 1 after optimization experiments. In addition, the specific spectra selected by the glow discharge spectrometer for each element in the zinc-aluminum coating are shown in Table 2.

[0100] Table 1 Optimal analysis parameters for glow discharge surface analysis

[0101] project Optimal analysis parameters project Optimal analysis parameters Vacuuming time 40s Discharge current 10mA Rinse time 15s Discharge voltage 1000V Single Integral Time 70ms Total Excitation Time 180s

[0102] Table 2 shows the specific spectral lines selected by the glow discharge spectrometer for each element within the zinc-aluminum coating.

[0103]

[0104]

[0105] (2) Determine the standard samples and analysis range: The analysis object of glow discharge surface is generally the zinc-aluminum coating on the surface of steel plate. Therefore, in order to make the working curve of the analysis method cover the content range of each element contained in the coating and have an appropriate content gradient, it is necessary to use sputtering rate and relative sputtering rate to correct the intensity and mass fraction of each element in different matrices. The standard samples selected in this process are shown in Table 3.

[0106] Table 3 Elemental Mass of Standard Samples

[0107]

[0108]

[0109] (3) Processing of standard samples: The surface of the standard sample is first polished with water using 120-grit silicon carbide sandpaper. After polishing, the surface is immediately rinsed with anhydrous alcohol and then dried with hot air at a temperature of 60℃~90℃.

[0110] (4) Preparation of calibration working curves: After surface treatment, each standard sample is excited under optimized glow discharge surface analysis parameters. After relative sputtering rate correction, calibration working curves for each standard sample element are established.

[0111] 2. Determine the quantitative relationship between the mass of Fe, Zn, Al, and Si in the zinc-aluminum coating and depth, including the following steps:

[0112] (1) Prepare a flat sample with a length greater than 20 mm and a width less than 100 mm for the zinc-aluminum coating to be analyzed. Do not rub the surface of the sample with any mechanical means.

[0113] (2) Select a clean beaker and pour in an acetone solution at 20℃~25℃. Completely immerse the zinc-aluminum coating sample to be tested in the acetone solution. Then, place the beaker in an ultrasonic cleaner and ultrasonically clean it at a frequency of 85Hz for 3min~5min to remove grease, organic contaminants, and particulate matter from the sample surface. Finally, remove the zinc-aluminum coating sample to be tested and dry it with hot air at 60℃~90℃ to obtain a pretreated sample.

[0114] (3) Place the pretreated sample itself as the cathode on the light source and excite the pretreated sample using the working parameters of the glow discharge spectrometer as shown in Table 1.

[0115] (4) The pretreated sample was peeled off layer by layer in a glow discharge spectrometer to detect the chemical composition of each layer. Measurement was stopped when the composition measured by the glow discharge spectrometer matched the chemical composition of the steel substrate. Then, based on the relationship between the depth of each measurement and the mass of the chemical components Fe, Zn, Al, and Si, curves were plotted showing the relationship between the content of these chemical components and the depth of the zinc-aluminum coating. The results are as follows: Figure 3 As shown, the thickness of the coating is determined by the quantitative relationship between the sum of the major element Fe content in the coating and the coating depth. The total mass of Zn, Al, and Si in the coating is obtained by integrating the Zn-h, Al-h, and Si-h curves with the coating depth and the coating depth of the zinc-aluminum coating to be tested.

[0116] 3. Calculation of the mass fraction of Zn, Al, and Si elements in zinc-aluminum coatings:

[0117] (1) Calculation core principle: Integrate the element mass fraction with time or coating thickness at the coating depth, transform the function of time into a function of depth, and analyze the depth of zinc-aluminum coating layer by layer.

[0118] (2) Calculation of coating element integral depth L: Unlike single-element coatings such as zinc plating, zinc-aluminum coatings contain a variety of elements. Therefore, the change in the mass fraction of Zn cannot be used as the basis for judging the coating thickness. Thus, the change in the mass fraction of the matrix element Fe is used as the basis for measuring the coating thickness. The coating thickness integral formula is set on the instrument as follows:

[0119] L=DepthW("Fe2", 0.84, -1)

[0120] The formula indicates that the result will return a value that is calculated by traversing from right to left in the spectrum. The depth value corresponding to the horizontal axis of the first curve when the Fe mass fraction in the Fe2 channel first drops from the highest value to 84% is the thickness of the zinc-aluminum coating to be tested.

[0121] (3) Calculation of average mass fraction: By summing the coating mass of all elements, the mass of each element Zn, Al, and Si is divided by the total mass of Zn, Al, and Si in the zinc-aluminum coating to be tested to obtain the average mass fraction of Zn, Al, and Si in the coating.

[0122] The average mass fractions of Zn, Al, and Si in the coating were determined to be 61%, 7%, and 9%, respectively.

[0123] Comparative Example 1

[0124] Based on the content disclosed in Example 1, the following modifications are made:

[0125] The specific steps for using a chemical dissolution method are as follows:

[0126] 1. Pretreatment: Clean the surface to be treated with anhydrous ethanol to remove oil, dust and other impurities.

[0127] 2. Weighing: Weigh the sample before acid washing.

[0128] 3. Pickling: Immerse the sample in 50 mL of 10% hydrochloric acid aqueous solution and control the pickling time at room temperature to 5 min to 10 min to ensure effective dissolution of the coating and avoid excessive corrosion of the substrate.

[0129] 4. Washing and drying: After pickling, take out the sample and immediately rinse the surface of the sample with plenty of water to remove the residual acidic and alkaline components on the surface of the sample. Then dry the sample at low temperature to obtain the pickled sample.

[0130] 5. Weighing: Weigh the sample before pickling. Based on the mass of the sample before pickling and the mass of the sample before pickling, obtain the mass difference before and after pickling. This mass difference is the mass of the zinc-aluminum coating peeled off the sample surface.

[0131] 6. Preparation of test solution: After acid washing, the solution is diluted to 100 mL with pure water and then used for testing by wet chemical analysis methods such as ICP and AAS.

[0132] Comparative Example 2

[0133] Based on the content disclosed in Example 1, the following modifications are made:

[0134] The physical peeling method involves the following steps:

[0135] 1. Pretreatment: Clean the surface of the sample to be treated with anhydrous ethanol to remove oil, dust and other impurities. Then clean the peeling tools, such as files, with anhydrous ethanol.

[0136] 2. Scraping: First, place a clean filter paper or A4 paper under the cleaned sample. Then, use a file at a 45° angle to the sample to scrape the surface coating downwards at a uniform speed. Be careful not to use too much force with the scraper to avoid scratching the substrate, so as to obtain the coating powder.

[0137] 3. Weighing: Weigh the collected coating powder and record the mass.

[0138] 4. Dissolution: Dissolve the coating powder in a 10% hydrochloric acid aqueous solution. After complete dissolution, bring the volume to 100 mL. Then, use wet chemical analysis methods such as ICP and AAS to test the volume of the solution.

[0139] Relevant experimental and effect data:

[0140] Specific standard samples were selected and tested using the methods of Example 1, Comparative Example 1, and Comparative Example 2. The accuracy of the tests was examined, and the results are shown in Table 4.

[0141] Table 4. Accuracy distribution of detection methods in Example 1, Comparative Example 1, and Comparative Example 2

[0142]

[0143] As shown in Table 4, the method for rapid detection of Zn, Al, and Si content in zinc-aluminum coatings provided in this application uses a glow discharge spectrometer for glow discharge surface analysis. This method does not require destructive treatment of the zinc-aluminum coating, thereby avoiding substrate effects during the detection process and improving the accuracy of zinc-aluminum coating detection to 99%.

[0144] In addition, this application provides a method for rapid detection of Zn, Al, and Si content in zinc-aluminum coatings. This method uses a glow discharge spectrometer for glow discharge surface analysis. Based on the advantages of glow discharge surface analysis, such as fast analysis speed, high analysis accuracy, and low detection limit, it can obtain not only the composition information of the zinc-aluminum coating, but also the thickness and mass distribution information of the zinc-aluminum coating.

[0145] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed in this application.

Claims

1. A method for rapidly detecting the content of Zn, Al, and Si elements in zinc-aluminum coatings, characterized in that, The method includes: The zinc-aluminum coating to be tested was ultrasonically cleaned to obtain a pretreated sample; The pretreated sample was subjected to glow discharge spectroscopy for surface analysis to determine the relationship between the mass of Fe, Zn, Al and Si in the zinc-aluminum coating and the coating depth h of the zinc-aluminum coating, layer by layer. By plotting the horizontal and vertical axis graphs, Fe-h curves, Zn-h curves, Al-h curves and Si-h curves were obtained, respectively. Based on the Zn-h curve, the Al-h curve, and the Si-h curve, the total mass of Zn, Al, and Si in the zinc-aluminum coating to be tested is calculated respectively. Using the Fe-h curve as a standard curve, the zinc-aluminum coating depth and the iron mass fraction within the zinc-aluminum coating are determined respectively. When the iron mass fraction within the zinc-aluminum coating of the Fe-h curve is ≤84%, the zinc-aluminum coating depth of the Fe-h curve is determined as the zinc-aluminum coating thickness. The masses of Zn, Al, and Si in the Zn-h curve, Al-h curve, and Si-h curve are integrated with respect to the thickness of the zinc-aluminum coating or the time of the glow discharge surface analysis, respectively, to obtain the mass of Zn, the mass of Al, and the mass of Si in the zinc-aluminum coating to be tested. The average mass of Zn, the average mass of Al, and the average mass of Si in the zinc-aluminum coating to be tested are respectively used as the numerators, and the total mass of Zn, Al, and Si in the zinc-aluminum coating to be tested is used as the denominator to obtain the average mass of Zn, the average mass of Al, and the average mass of Si in the zinc-aluminum coating to be tested. The average mass fractions of Zn, Al, and Si in the zinc-aluminum coating to be tested are obtained based on the average mass of Zn, Al, and Si in the zinc-aluminum coating to be tested and the total mass of Zn, Al, and Si in the zinc-aluminum coating to be tested. The glow discharge surface analysis includes a vacuuming phase, a discharge phase, a rinsing phase, and a single integration phase. The vacuuming time is 35s to 45s, the voltage of the discharge phase is 995V to 1005V, the current of the discharge phase is 5mA to 15mA, the rinsing time is 10s to 20s, and the single integration time is 65ms to 75ms.

2. The method according to claim 1, characterized in that, The excitation time for the glow discharge surface analysis is ≥180s.

3. The method according to claim 1, characterized in that, The step of ultrasonically cleaning the zinc-aluminum coating to be tested to obtain a pretreated sample includes the following steps: The zinc-aluminum coating to be tested was ultrasonically cleaned using an organic solvent, followed by hot air drying to obtain a pretreated sample.

4. The method according to claim 3, characterized in that, The ultrasonic cleaning frequency is 80Hz to 90Hz, the ultrasonic cleaning time is 3min to 5min, and the ultrasonic cleaning temperature is 20℃ to 25℃.

5. The method according to claim 3, characterized in that, The temperature of the hot air drying is 60℃~90℃.

6. The method according to claim 1, characterized in that, The step of calculating the total mass of Zn, Al, and Si in the zinc-aluminum coating to be tested based on the Zn-h curve, the Al-h curve, and the Si-h curve, respectively, includes the following steps: The masses of Zn, Al, and Si in the Zn-h curve, Al-h curve, and Si-h curve are integrated with respect to the coating depth of the zinc-aluminum coating to be tested, respectively, to calculate the total mass of Zn, Al, and Si in the zinc-aluminum coating to be tested.

7. The method according to claim 1, characterized in that, The method further includes: The standard sample is surface treated to obtain a pretreated standard sample; The pretreated standard samples were subjected to glow discharge surface analysis to obtain standard variation curves; The standard variation curve is corrected based on the difference between sputtering rate and relative sputtering rate to obtain a corrected curve; The parameters for the glow surface analysis are optimized based on the calibration curve.

Images