Data acquisition method of oriented silicon steel inhibitor

Abstract

The invention belongs to the technical field of analysis and detection of oriented silicon steel, and particularly relates to a data acquisition method of an oriented silicon steel inhibitor, which comprises the following steps: mechanical grinding and polishing, electrolytic erosion, ultrasonic oscillation and drying, and scanning electron microscope observation. The method provided by the invention avoids the defects of complex sample preparation, long period and high cost of the traditional TEM means; a plurality of problems existing in an existing SEM sample preparation method are improved and even avoided, and the problems include that in the electrolytic erosion process, solute element membranoid substances pollute the surface, solute elements are accumulated to form a new particle phase, and the solute elements change components and structures of original fine precipitated particles.

Description

Technical Field

[0001] The invention belongs to the technical field of analysis and detection of oriented silicon steel, and particularly relates to a data acquisition method for oriented silicon steel inhibitors. Background Art

[0002] Fine precipitates in grain-oriented silicon steel, sized at hundreds of nanometers or less, are called inhibitors and are a core area of ​​control and research in silicon steel production. Based on factors such as particle size, volume fraction, and grain diameter at a specific temperature, the inhibitor system plays a role in either hindering or allowing grain boundary movement, thereby affecting grain growth during the low-temperature stage or secondary recrystallization phase. Ultimately, the product's performance is determined by the perfection and orientation sharpness of the Goss grains. Transmission electron microscopy (TEM) is the traditional method for observing inhibitors, but TEM sample preparation is cumbersome, the test cycle is long, and the observation area is limited. To adapt to the global, systematic, rapid, accurate, and large-scale analysis requirements of inhibitor research, the industry has increasingly used scanning electron microscopy (SEM) combined with semi-quantitative X-ray energy dispersive spectroscopy (EDX) composition analysis to observe inhibitors.

[0003] Several publications have reported on sample preparation and analysis techniques for inhibitor observation using SEM, such as An Fenghui's paper "Application of Non-Aqueous Solvent Selective Constant Potential Electrolytic Etching in Grain-Oriented Silicon Steel" at Northeastern University and Wang Xianhui et al.'s patent "A Method for Analyzing Inhibitors in Grain-Oriented Silicon Steel" at Shougang. Electropolishing with organic solutions, such as a 10% AA solution (tetramethylammonium chloride: acetylacetone: methanol = 1:10:89), is a common choice. However, this approach is not entirely reliable in practice. This method cannot completely prevent the accumulation of solutes on the steel surface after electrolytic etching, forming a solute film (primarily composed of solute elements such as Cu, Mn, and S, hence the term "solute film") or particle artifacts. Furthermore, it does not provide a method for identifying such artifacts, potentially distorting inhibitor data.

[0004] The causes of these organic solution etching artifacts are somewhat similar to those of copper-rich (or ε-Cu) particles that appear during etching and polishing with acidic chemicals such as nitric acid. However, surface particles etched with organic solutions rarely cluster or accumulate, and visually appear much more realistic than copper-rich particles. Therefore, these artifacts are often difficult to discern and are often mistaken for real morphology by many researchers. Researchers at Carnegie Mellon University in the United States have previously observed and demonstrated the formation of sulfide artifacts or new phases when organic solutions etch steel samples (the paper "Formation of Copper Sulfide Artifacts During Electrolytic Dissolution of Steel"). However, there are currently no sample preparation methods to improve this phenomenon, nor are there any evaluation methods to identify the presence of new phases or artifacts in the SEM field of view. Summary of the Invention

[0005] The present invention aims to provide a data acquisition method for grain-oriented silicon steel inhibitors, which can effectively improve or even avoid several problems existing in existing SEM sample preparation methods, including surface contamination by solute element films during electrolytic etching, accumulation of solute elements to form new particle phases, and solute elements changing the composition and structure of original fine precipitated particles.

[0006] According to the technical solution of the present invention, the data collection method of the grain-oriented silicon steel inhibitor comprises the following steps: S1: Mechanically grinding and polishing the oriented silicon steel sample to obtain a mechanically ground and polished sample; S2: electrolytically eroding the mechanically polished sample using a water pump electrolyzer to obtain an electrolytically eroded sample; S3: Cleaning and drying the electrolytically corroded sample to obtain a test sample; S4: Fix the test sample on the sample stage of the scanning electron microscope, use the Inlens mode, and use a magnification of 10,000 to 50,000 times to take selected area photos and record the inhibitor conditions of different grains.

[0007] Furthermore, in step S1, mechanical polishing includes metallographic grinding to 2500# sandpaper and polishing with Al2O3 polishing agent.

[0008] Furthermore, in step S2, the parameters of electrolytic corrosion are set as follows: water pump speed 1200-2000 rpm; voltage 5-15 V; time 5-15 s; electrolysis temperature 0-15°C.

[0009] Furthermore, in step S2, the electrolyte used for electrolytic etching includes, by mass fraction, 0.6% to 1.4% tetramethylammonium chloride and 8% to 12% acetylacetone, with the remainder being methanol.

[0010] Furthermore, in step S3, the cleaning is performed by placing the electrolytically eroded sample in methanol and ultrasonically oscillating it for 1 to 5 minutes.

[0011] Furthermore, in step S4, the test sample is fixed to the sample stage using carbon conductive glue, and bridged using copper conductive glue.

[0012] Furthermore, in step S4, the acceleration voltage of the scanning electron microscope is set to 5-15 kV, and the working distance is 3-9 mm.

[0013] Furthermore, before or after step S4, a judgment step is further included to judge whether there is a solute film or particle artifact on the surface of the detection sample.

[0014] Furthermore, the determination step includes image analysis and component analysis; The image analysis is to half-cover the surface of the mechanically polished sample with aluminum foil as a standard sample, obtain scanning electron microscope photos of the standard sample and the test sample respectively, and perform grayscale processing, and judge whether there is a solute film or particle artifact on the surface of the test sample based on the grayscale data of the standard sample and the test sample; The component analysis is to obtain surface component information of the mechanically polished sample and the test sample respectively, compare them, and determine whether there is a solute film on the surface of the test sample.

[0015] Compared with the existing technology, the technical solution of the present invention has the following advantages: it avoids the shortcomings of traditional TEM sample preparation methods such as complex sample preparation, long cycle and high cost; it improves or even avoids several problems existing in the existing SEM sample preparation method, including solute element film contamination of the surface during the electrolytic corrosion process, solute element accumulation to form new particle phases, solute elements changing the composition and structure of the original fine precipitated particles, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The presence of film material can be directly determined by (a) the appearance of layered discontinuities on the surface or the presence of film cracks; (b) the appearance of fluffy cracks after the film has dried and been left for a long time.

[0017] Figure 2 The presence of particle artifacts can be directly determined in the following cases: (a) the particles are dense and translucent; (b) the particles are irregular in shape and have unclear outlines; and (c) the particles clearly do not conform to the precipitation characteristics.

[0018] Figure 3 This is the morphology of the inhibitor and substrate after electrolytic corrosion in Example 1.

[0019] Figure 4 This is the morphology of the inhibitor and substrate after electrolytic corrosion in Example 2.

[0020] Figure 5This is the morphology of particles and matrix after electrolytic corrosion in Comparative Example 1.

[0021] Figure 6 This is the morphology of particles and matrix after electrolytic corrosion in Comparative Example 2.

[0022] Figure 7 This is the morphology of particles and matrix after electrolytic corrosion in Comparative Example 3. DETAILED DESCRIPTION

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0024] According to the thin-film principle of electrolytic polishing, a thin film of reaction products (or solute film) forms on the sample surface during electropolishing. This film is thinner on convex surfaces and thicker on concave surfaces. Consequently, the resistance is low, the current density is high, and dissolution is rapid in convex areas, while dissolution is slow in concave areas. As the surface becomes more concave, the height difference decreases, and the sample surface is gradually eroded and polished flat. This solute film can be ignored when observing at relatively low magnifications, but it becomes significant when observing inhibitors at high magnifications (typically 30,000 to 50,000 times or more). The present invention addresses the problem that the appearance of solute particle artifacts or solute films on the eroded sample surface originates from this electrolytic film.

[0025] Therefore, the electrolytic polishing method for inhibitors differs from traditional electrolytic polishing in that the appearance or residual solute film on the sample surface should be avoided as much as possible. Experiments in this invention have shown that once the solute film reaches a certain thickness, it becomes difficult to remove, and even high-voltage breakdown in the later stages of electrolysis cannot remove it. (At higher voltages, the film may in some cases transform into clusters of nanoscale spherical particles that accumulate on the sample surface.) Therefore, the key to eliminating the solute film is to prevent the formation of a stable solute film. Although this process only erodes the sample and has a limited polishing effect, practical verification has shown that this slightly uneven, low-level polished surface is still acceptable for inhibitor observation (as shown in Example 2).

[0026] Based on this, the present invention provides a data collection method for grain-oriented silicon steel inhibitors, comprising the following steps: S1: Mechanically grinding and polishing the oriented silicon steel sample to obtain a mechanically ground and polished sample; S2: electrolytically eroding the mechanically polished sample using a water pump electrolyzer to obtain an electrolytically eroded sample; S3: Cleaning and drying the electrolytically corroded sample to obtain a test sample; S4: Fix the test sample on the sample stage of the scanning electron microscope, use the Inlens mode, and use a magnification of 10,000 to 50,000 times to take selected area photos and record the inhibitor conditions of different grains.

[0027] The electrolytic etching method of the present invention utilizes a water-pump electrolyzer, rather than conventional stationary electrolysis. The sample is placed in a corrosion tank within a sample tray above the water-pump electrolyzer. During the electrolysis process, a magnetic stirrer draws electrolyte from the tank, continuously flushing the sample upward and forming an electrolytic circuit. During this process, the electrolyte continuously flushes the sample surface, removing solute elements and continuously disrupting the steady-state formation of the electrolytic film.

[0028] Among them, the oriented silicon steel sample is processed into the required size from the plane or cross-section of the oriented silicon steel after each process according to the needs, and is obtained by hot embedding with conductive resin. The processing method can be laser cutting.

[0029] In some preferred embodiments, step S1 mechanical polishing includes metallographic grinding to 2500# sandpaper and polishing with Al2O3 polishing agent. Specifically, metallographic grinding needs to ensure that the sample surface is scratched in only one direction, and the grinding depth is determined by the position to be observed. For rolled surface samples, the near surface layer, middle layer and center layer are usually observed, that is, the 1 / 8, 1 / 4 and 1 / 2 thickness layers of the sample. It is necessary to ensure that the target thinning thickness is achieved after the last 2500# sandpaper grinding. Al2O3 (particle size can be 1.0~2.0 μ m) Polishing agent is used to polish the surface until there are no scratches or polishing marks, no black spots or impurities. By increasing the degree of mechanical polishing, it can take on part of the electrolytic polishing effect.

[0030] In some preferred embodiments, in step S2, the parameters of electrolytic corrosion are set as follows: water pump speed 1200~2000 rpm, for example, it can be 1200 rpm, 1300 rpm, 1500 rpm, 1700 rpm, 1900 rpm, 2000 rpm, etc.; voltage 5~15 V, for example, it can be 5 V, 7 V, 10 V, 12 V, 15 V, etc.; time 5~15 s, for example, it can be 5 s, 7 s, 10 s, 12s, 15 s, etc.; electrolysis temperature 0~15°C, for example, it can be 0°C, 3°C, 5°C, 10°C, 15°C, etc. Among them, the water pump speed is controlled at a high speed level to ensure the cleaning speed of the electrolysis products, which can avoid the reuse of the electrolyte to prevent secondary contamination of the surface by the pre-dissolved substances; voltage is an important influencing factor of the thickness of the electrolytic solute film, and the control of voltage is coordinated with the electrolysis temperature to control the rate of matrix dissolution and solute precipitation at a lower level; the electrolysis time is controlled to ensure that the sample surface is fully eroded and slightly polished.

[0031] Specifically, the electrolyte used for electrolytic etching consists of 0.6% to 1.4% tetramethylammonium chloride and 8% to 12% acetylacetone, with the balance being methanol. Each electrolysis should be performed using fresh or unused electrolyte. Electrolytic etching can also be immediately rinsed with methanol to avoid secondary contamination.

[0032] In some preferred embodiments, the cleaning in step S3 is performed by placing the electrolytically eroded sample in methanol (analytical grade or anhydrous methanol) and ultrasonically oscillating the sample for 1 to 5 minutes, for example, 1 minute, 2 minutes, 3 minutes, 4 minutes, 5 minutes, etc. After the ultrasonic oscillation, the sample can be dried with a hair dryer until completely dry.

[0033] In some preferred embodiments, step S4 uses carbon conductive adhesive to secure the test sample to the sample stage, and copper conductive adhesive is used as a bridge to enhance conductivity. The scanning electron microscope has an accelerating voltage of 5 to 15 kV, for example, 5 kV, 8 kV, 10 kV, 13 kV, 15 kV, etc.; the working distance is 3 to 9 mm, for example, 3 mm, 4 mm, 6 mm, 8 mm, 9 mm, etc.

[0034] When shooting selected areas and recording the inhibitor conditions of different grains, there are usually fewer inhibitors in the high-magnification field of view. In this case, you can first shoot and record at low magnification, and count the total area of ​​all intact grains in the low-magnification field of view; then record the inhibitor information in all these intact grains at high magnification, and then summarize the overall inhibitor morphology and distribution through data processing and calculation.

[0035] In some preferred embodiments, a determination step is further included before or after step S4 to determine whether there is a solute film or particle artifact on the surface of the sample to be tested. The determination step is mainly used to evaluate the feasibility of using the present invention to test the sample.

[0036] Specifically, the judgment step includes image analysis and component analysis; Image analysis involves half-covering the surface of a mechanically polished sample with aluminum foil as a standard sample. Scanning electron microscope images of the standard sample and the test sample are obtained and grayscale processed. The grayscale data of the standard sample and the test sample are used to determine whether there are solute films or particle artifacts on the test sample surface. Component analysis is to obtain the surface composition information of the mechanically polished sample and the test sample respectively, compare them, and determine whether there is a solute film on the surface of the test sample.

[0037] The above image analysis and component analysis methods are mainly based on: If solute elements are present on the sample surface after electrolysis, the aggregation typically manifests as: 1) a thin solute film; 2) the uneven distribution of solute elements on top of the surface solute film, resulting in translucent or opaque solute particles. Clear boundaries between solute particles can make it difficult to determine whether they are electrolysis products. When the solute forms only a thin film, and this thin translucent film does not alter the morphology of the true inhibitor particles, it can affect EDS (energy dispersive spectrometer) point analysis results. Furthermore, since there is no guarantee that only a film will form without artifacts of solute particles forming aggregates, even a thin solute film is unacceptable for inhibitor observation.

[0038] For film image identification, contrast comparison is used. When observed in the BSE mode of an electron microscope, the substrate covered with a solute film appears grayish. This grayness can be quantified using contrast (i.e., grayscale). The deviation from the normal substrate grayscale can also be used to assess the degree of film accumulation. It should be noted that to eliminate the influence of topographic contrast and retain only compositional contrast, BSE mode should be used for observation, rather than other modes such as SE2.

[0039] In addition, image analysis and component analysis are mainly aimed at situations where it is difficult to distinguish the presence of solute film or solute particles with the naked eye. For the following situations, it can be directly judged as sample image distortion: ① The surface of the film material has cracks, faults or hairy cracks after drying (such as Figure 1 ); ② The particles are translucent, irregular in shape or obviously do not conform to the precipitation characteristics (such as Figure 2 ).

[0040] In some embodiments, the specific operations of image analysis and component analysis are as follows: (1) Image analysis: The test sample and the standard sample are placed in the electron microscope chamber at the same time. The test sample is obtained in step S3, and the standard sample is obtained by half-covering the surface of the mechanically polished sample obtained in step S2 with aluminum foil. Use the BSE mode, adjust the brightness and contrast to appropriate values, and do not change the brightness, contrast and working distance values ​​during subsequent scanning and shooting. For the standard sample, the BSE mode is magnified to 2,000 to 10,000 times, and the SEM photos of the mechanically polished sample and the aluminum foil are recorded respectively. For the test sample, the SEM photos are recorded in the BSE mode at the same magnification. Use image processing software such as Photoshop to calculate the grayscale value (A) of the mechanically polished sample. 标准 :0~255)、Observe the gray value of the sample (A 观察 :0~255) and aluminum foil gray value (A 铝箔 :0~255); calculate the deviation value of the gray value of the test sample: (A 观察 -A 标准 ) / (A 铝箔 -A标准 ), and a deviation value of less than 5% can be evaluated as the absence of solute film or particle artifacts.

[0041] (2) Composition analysis: Select a field of view with a small number of particles, perform EDS point analysis on the test sample, and collect composition information; select different fields of view, repeat the operation, and collect no less than 20 pieces of composition information; in the EDS matrix composition, ([Mn]+[S])-([Mn] 标准 +[S] 标准 )<0.5% and [Cu]-[Cu] 标准 <0.5%, it is considered that there is no solute film in the field of view corresponding to the component information, where [Mn] 标准 , [S] 标准 , [Cu] 标准 Where [Mn], [S], and [Cu] are the standard composition of the sample (measured by direct reading spectroscopy, ICP-OES, etc., or the intermediate composition of unannealed samples, in wt.%). If the percentage of fields without solute film is ≥90%, the sample is considered to be free of solute film. As you can imagine, due to the semi-quantitative nature of EDS, the more compositional information collected, the higher the accuracy. Example 1

[0042] The sample is a Fe-3%Si-0.5%Cu oriented silicon steel hot-rolled plate with a thickness of 2.3 mm. The sample preparation and analysis (data collection) methods are as follows: S1: Use laser cutting to process the oriented silicon steel into specimens with the size of length * width * thickness = 12mm * 10mm * 2.3mm, with the burr-free surface (rolled surface) facing downward and hot-mounted using conductive resin.

[0043] S2: Grind the hot-mounted specimens sequentially with 2500# sandpaper. Ensure that 0.575mm is removed at the end of the last grinding. Then use 2.0 μ Mechanically polish with Al2O3 diamond polishing agent with particle size of m to a bright surface without scratches or black spots.

[0044] S3: Electrolytic polishing was performed using a water pump electrolyzer. The organic electrolyte was 1% tetramethylammonium chloride + 10% acetylacetone + 89% methanol (by weight concentration). The water pump speed was 1200 rpm, the electrolysis voltage was 8 V, the electrolysis time was 12 s, and the electrolysis temperature was 10°C. After the electrolysis was completed, the sample was immediately washed with methanol, and then immersed in the methanol solution for ultrasonic oscillation for 2.5 min and dried with a hair dryer until completely dry.

[0045] S4: The sample was fixed to the sample stage using carbon conductive glue and bridged with copper conductive glue to enhance the conductivity of the sample. In Inlens mode, the magnification was set to 50,000 times according to the inhibitor particle size level, the acceleration voltage was set to 8kV, and the working distance was 3.5-4.0mm. Different fields of view were selected for shooting. The photos taken are as follows: Figure 3 shown.

[0046] Image analysis of the photographs taken in this example: Using BSE mode, brightness and contrast values ​​were adjusted to appropriate values ​​and maintained constant, with a working distance of 8 mm. SEM photographs of the standard sample and the observed sample grains were taken within a 5,000x field of view. Statistics revealed an average grayscale value of 62 for the standard sample, 59 for the observed sample, and 125 for the aluminum foil. The contrast deviation of the observed sample was 4.8%, less than the standard value of 5%. Therefore, the sample surface was considered uncontaminated.

[0047] EDS energy spectrum analysis was performed on the matrix position of the sample in this embodiment, and the composition information of 20 matrix fields was collected. The standard composition and partial composition information are shown in Table 1. The EDS matrix composition is consistent with ([Mn]+[S])-([Mn] 标准 +[S] 标准 )<0.5% and [Cu]-[Cu] 标准 The number of conditions with a value <0.5% is 18 (90% of the viewing field can be considered to be free of contamination). Therefore, the sample surface can be considered free of contamination.

[0048] Table 1 Matrix EDS point analysis results (partial, site 1~5) and standard components wt.% Example 2

[0049] The sample is a Fe-3%Si-0.5%Cu oriented silicon steel single cold-rolled plate with a thickness of 0.66 mm. The sample preparation and analysis methods are as follows: S1: Use laser cutting to process the oriented silicon steel into a sample with the size of length * width * thickness = 12mm * 10mm * 0.66mm, with the burr-free surface (rolled surface) facing downward and hot-mounted using conductive resin.

[0050] S2: Grind the hot-mounted specimens sequentially with 2500# sandpaper. Ensure that 0.165mm is removed at the end of the last grinding. Then use 1.5 μ Mechanically polish with Al2O3 diamond polishing agent with particle size of m to a bright surface without scratches or black spots.

[0051] S3: Electrolytic polishing was performed using a water pump electrolyzer. The organic electrolyte was 1% tetramethylammonium chloride + 10% acetylacetone + 89% methanol (by weight concentration). The water pump speed was 1800 rpm, the electrolysis voltage was 12 V, the electrolysis time was 8 s, and the electrolysis temperature was 10°C. After the electrolysis was completed, the sample was immediately washed with methanol, and then immersed in the methanol solution for ultrasonic oscillation for 2.5 minutes and dried with a hair dryer until completely dry.

[0052] S4: The sample was fixed to the sample stage using carbon conductive glue and bridged with copper conductive glue to enhance the conductivity of the sample. In Inlens mode, the magnification was set to 30,000-50,000 times according to the inhibitor particle size level, the acceleration voltage was set to 5kV, and the working distance was 4.5-6.0mm. Different fields of view were selected for shooting. The photos taken are as follows: Figure 4 shown.

[0053] Image analysis of the photographs taken in this example: Using BSE mode, brightness and contrast values ​​were adjusted to appropriate values ​​and maintained constant, with a working distance of 8 mm. SEM photographs of the standard sample and the observation sample were taken within a 5,000x field of view. Statistics revealed an average grayscale value of 68 for the standard sample, 65 for the observation sample, and 138 for the aluminum foil. The contrast deviation of the observation sample was 4.3%, less than the standard value of 5%. Therefore, the sample surface was deemed uncontaminated.

[0054] EDS energy spectrum analysis was performed on the matrix position of the sample in this embodiment, and the composition information of 40 matrix fields was collected (composition data omitted). The EDS matrix composition was consistent with ([Mn]+[S])-([Mn] 标准 +[S] 标准 )<0.5% and [Cu]-[Cu] 标准 The number of conditions with a value <0.5% is 37 (93% of the field of view can be considered to be free of contamination). Therefore, the sample surface can be considered free of contamination.

[0055] In addition, since the polishing process does not produce a stable solute film, the surface concave and convex of the sample in this embodiment is relatively more obvious, such as Figure 4 As shown in (a), this concave-convex morphology does not affect the observation of the inhibitor. Comparative Example 1

[0056] The sample is a Fe-3%Si-0.5%Cu oriented silicon steel single cold-rolled plate with a thickness of 0.67 mm. The sample preparation and analysis methods are as follows: S1: Use laser cutting to process the oriented silicon steel into a sample with the size of length * width * thickness = 12mm * 10mm * 0.67mm, with the burr-free surface (rolled surface) facing downward and hot-mounted using conductive resin.

[0057] S2: Grind the hot-mounted specimens sequentially with 2500# sandpaper. Ensure that 0.167mm is removed at the end of the last grinding. Then use 2.0 μ Mechanically polish with Al2O3 diamond polishing agent with particle size m to a bright surface without scratches or black spots S3: Electrolytic polishing was performed using a water pump electrolyzer. The organic electrolyte was 1% tetramethylammonium chloride + 10% acetylacetone + 89% methanol (by weight concentration). The water pump speed was 1500 rpm, the electrolysis voltage was 20 V, the electrolysis time was 15 s, and the electrolysis temperature was 10°C. After the electrolysis was completed, the sample was immediately washed with methanol, and then immersed in the methanol solution for ultrasonic oscillation for 2.5 minutes and dried with a hair dryer until completely dry.

[0058] S4: The sample was fixed to the sample stage using carbon conductive glue and bridged with copper conductive glue to enhance the conductivity of the sample. In Inlens mode, the magnification was set to 30,000 times based on the inhibitor particle size level, the acceleration voltage was set to 5kV, and the working distance was 5.5-6.0mm. Different fields of view were selected for shooting. The photos taken are as follows: Figure 5 shown.

[0059] Image analysis of the photographs taken for this comparative example: Using BSE mode, brightness and contrast were adjusted to appropriate values ​​and then maintained constant, with a working distance of 8mm. SEM images of the standard sample and the grains of the observed sample were taken at a field of view of 5,000x. Statistics showed an average grayscale of 93 for the standard sample, 84 for the observed sample, and 122 for the aluminum foil. The contrast deviation of the observed sample was 31%, exceeding the standard value by 5%. Therefore, it is believed that the sample surface is contaminated.

[0060] EDS point analysis was performed on the matrix position of the comparative example sample, and the composition information of 20 matrix fields was collected. The standard composition and part of the EDS composition information are shown in Table 2. The EDS matrix composition is consistent with ([Mn]+[S])-([Mn] 标准 +[S] 标准 )<0.5% and [Cu]-[Cu] 标准 The number of conditions with a value of <0.5% is 1 (only 5% of the viewing field can be considered free of contamination). Therefore, it can be considered that the sample surface is contaminated.

[0061] Table 2 Matrix EDS composition information (partial) wt.%

[0062] The contamination is believed to be caused by the high electrolysis voltage in this comparative example. This increases the amount of solute elements dissolved in the steel, leading to their accumulation on the substrate surface. This results in the appearance of newly formed solute films and solute particle artifacts during the electrolytic erosion process. The solute films in most areas of this sample are not visually detectable and require verification and identification using methods such as image analysis and compositional analysis. Comparative Example 2

[0063] The sample is a decarburized Fe-3%Si-0.5%Cu oriented silicon steel plate with a thickness of 0.635 mm. The sample preparation and analysis methods are as follows: S1: Use laser cutting to process the oriented silicon steel into a sample with the size of length * width * thickness = 12mm * 10mm * 0.635mm, with the burr-free surface (rolled surface) facing downward and hot-mounted using conductive resin.

[0064] S2: Grind the hot-mounted specimens sequentially with 2500# sandpaper. Ensure that 0.159mm is removed at the end of the last grinding. Then use 2.0 μ Mechanically polish with Al2O3 diamond polishing agent with particle size m to a bright surface without scratches or black spots S3: Electrolytic polishing was performed using a water pump electrolyzer. The organic electrolyte was 1% tetramethylammonium chloride + 10% acetylacetone + 89% methanol (by weight concentration). The water pump speed was 1500 rpm, the electrolysis voltage was 30 V, the electrolysis time was 20 s, and the electrolysis temperature was 10°C. After the electrolysis was completed, the sample was immediately washed with methanol, and then immersed in the methanol solution for ultrasonic oscillation for 2.5 minutes and dried with a hair dryer until completely dry.

[0065] S4: The sample was fixed to the sample stage using carbon conductive glue and bridged with copper conductive glue to enhance the conductivity of the sample. In Inlens mode, the magnification was set to 30,000 times based on the inhibitor particle size level, the acceleration voltage was set to 8kV, and the working distance was 8.6mm. Different fields of view were selected for shooting. The photos taken are as follows: Figure 6 shown.

[0066] like Figure 6 As shown in (a), the artifact particles generated during the erosion process are densely packed. If the eroded surface is uneven, the particles will cluster on the convex areas due to gravity (the specimen plane is facing downward during electrolytic erosion). If the eroded surface is smooth, the particles will be evenly distributed. The presence of particle artifacts can be directly determined based on the non-precipitation morphology described above. The main causes of this situation are excessively high electrolytic erosion voltage and prolonged electrolysis time. Comparative Example 3

[0067] The sample is a Fe-3%Si-0.5%Cu oriented silicon steel hot-rolled plate with a thickness of 2.3 mm. The sample preparation and analysis methods are as follows: S1: Use laser cutting to process oriented silicon steel into specimens with the size of length * width * thickness = 12mm * 10mm * 2.3mm, with the burr-free surface (rolled surface) facing downward and hot-mounted using conductive resin.

[0068] S2: Grind the hot-mounted specimens sequentially with 2500# sandpaper. Ensure that 0.575mm is removed at the end of the last grinding. Then use 1.5 μ Mechanically polish with Al2O3 diamond polishing agent with particle size of m to a bright surface without scratches or black spots.

[0069] S3: Electrolytic polishing was performed using a standing electrolyzer. The organic electrolyte was 1% tetramethylammonium chloride + 10% acetylacetone + 89% methanol (by weight concentration); the electrolysis voltage was 10 V, the electrolysis time was 10 s, and the electrolysis temperature was 10°C. After the electrolysis was completed, the sample was immediately washed with methanol, and then immersed in the methanol solution for ultrasonic oscillation for 2.5 minutes and dried with a hair dryer until completely dry.

[0070] S4: The sample was fixed to the sample stage using carbon conductive glue and bridged with copper conductive glue to enhance the conductivity of the sample. Observation was performed in Inlens mode with an accelerating voltage of 8kV and a working distance of 4.0-7.5mm. Different fields of view were selected for photography. Figure 7 .

[0071] like Figure 7 As shown, under high magnification (50,000 times, Figure 7 Middle a) The particle boundary is unclear and the surface is densely covered with paste, which is consistent with the characteristics of solute film; under low magnification (5000 times, Figure 7 In b), the film is discontinuous and the steel substrate beneath the film is exposed, indicating the presence of a solute film and particle artifacts. This phenomenon is primarily due to the difficulty of effectively removing the solute film using a stationary electrolysis method.

[0072] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the embodiments. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all embodiments here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A data collection method for grain-oriented silicon steel inhibitors, characterized in that: The following steps are included: S1: Mechanically grinding and polishing the oriented silicon steel sample to obtain a mechanically ground and polished sample; S2: electrolytically eroding the mechanically polished sample using a water pump electrolyzer to obtain an electrolytically eroded sample; S3: Cleaning and drying the electrolytically corroded sample to obtain a test sample; S4: Fix the test sample on the sample stage of the scanning electron microscope, use the Inlens mode, and use a magnification of 10,000 to 50,000 times to take selected area photos and record the inhibitor conditions of different grains.

2. The data collection method for grain-oriented silicon steel inhibitors according to claim 1, characterized in that: In step S1, mechanical grinding and polishing includes metallographic grinding to 2500# sandpaper and polishing with Al2O3 polishing agent.

3. The data collection method for grain-oriented silicon steel inhibitors according to claim 1, characterized in that: In step S2, the parameters of electrolytic corrosion are set as follows: water pump speed 1200-2000 rpm; voltage 5-15 V; time 5-15 s; electrolysis temperature 0-15°C.

4. The data collection method for grain-oriented silicon steel inhibitors according to claim 1 or 3, characterized in that: In step S2, the electrolyte used for electrolytic etching includes, by mass fraction, 0.6% to 1.4% tetramethylammonium chloride and 8% to 12% acetylacetone, with the remainder being methanol.

5. The data collection method for grain-oriented silicon steel inhibitors according to claim 1, characterized in that: In step S3, the cleaning step is to place the electrolytically eroded sample in methanol and ultrasonically vibrate for 1 to 5 minutes.

6. The data collection method for grain-oriented silicon steel inhibitors according to claim 1, characterized in that: In step S4, the test sample is fixed on the sample stage using carbon conductive glue, and bridged using copper conductive glue.

7. The data collection method for grain-oriented silicon steel inhibitors according to claim 1 or 6, characterized in that: In step S4, the acceleration voltage of the scanning electron microscope is set to 5-15 kV, and the working distance is 3-9 mm.

8. The data collection method for grain-oriented silicon steel inhibitors according to claim 1, characterized in that: Before or after step S4, a judgment step is further included to judge whether there is a solute film or particle artifact on the surface of the detection sample.

9. The data collection method for grain-oriented silicon steel inhibitors according to claim 8, characterized in that: The judging step includes image analysis and component analysis; The image analysis is to half-cover the surface of the mechanically polished sample with aluminum foil as a standard sample, obtain scanning electron microscope photos of the standard sample and the test sample respectively, and perform grayscale processing, and judge whether there is a solute film or particle artifact on the surface of the test sample based on the grayscale data of the standard sample and the test sample; The component analysis is to obtain surface component information of the mechanically polished sample and the test sample respectively, compare them, and determine whether there is a solute film on the surface of the test sample.

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