A method for measuring the oxygen content of the oxide layer in oriented silicon steel

Abstract

The present invention relates to a method for measuring the oxygen content of an oxide layer in oriented silicon steel, comprising the following steps: step S1, sample preparation: preparing a sample; step S2, detection, comprising: a first step: a sample is subjected to total oxygen content detection, and the total oxygen content is measured and recorded as O 总 ; The second step: another sample is sputtered and tested to determine the Si content of the sample; Step S3, data processing, including: The first step: draw a Si content curve, the position where the Si content reaches equilibrium is the total thickness of the oxide layer H 总 The area close to the decarburized plate surface and with Si content below the Si equilibrium line is the outer oxide layer thickness H 外 , H 内 =H 总 ‑H 外 ; The second step: draw the O content curve, with H 外 is the dividing point, and the integral area of ​​the O content curve on its left is S 外 , the integral area of ​​the O content curve on the right is S 内 ; The third step: Calculate the inner oxide layer O according to the measured total O content 内 =O 总 *S 内 / (S 内 +S 外 ) to accurately obtain the oxygen content of the inner oxide layer.

Description

Technical Field

[0001] The invention relates to the technical field of oriented silicon steel production, and in particular to a method for measuring the oxygen content of an oxide layer in oriented silicon steel. Background Art

[0002] Decarburization annealing is a very important step in the production process of oriented silicon steel. Its main purpose is: first, to reduce the C content; second, to increase the O content (i.e. SiO2) on the surface of the decarburized plate to form an oxide layer. The oxide layer is divided into an inner oxide layer and an outer oxide layer. The main phase of the outer oxide layer is FexOy, and the main phase of the inner oxide layer is SiO2. SiO2 and MgO generate a MgSiO3 bottom layer in the high-temperature annealing process to enhance the adhesion of the substrate. Therefore, the purpose of increasing the O content in the decarburization annealing process is to increase the oxygen content of the inner oxide layer.

[0003] Currently, patent JP-A-10-219359 discloses a method for indirectly measuring the O content by monitoring the concentration of elements such as Si and P in the surface layer of a steel plate during annealing. However, since the Si element not only combines with O to form SiO2 in the oxide layer, but also combines with O and Fe elements to form FeSiO3, Fe2SiO4, etc., the accuracy of the O content measured by this method is relatively poor.

[0004] Patent CN114113291A "A method for determining the content of major elements in multi-element alloys by glow mass spectrometry with proportional coefficient correction", patent CN114295603A "A method for simultaneously determining the content of multiple elements in aluminum alloys" and patent CN106645095A "A method for determining the content of silicon and aluminum in silicon aluminum plate coatings" all disclose methods for measuring the content of different elements using glow and making single-point or multi-point corrections to improve their accuracy. However, the maximum sputtering depth of glow discharge is only 200μm, and it is impossible to measure the element content of samples with a larger thickness, while the thickness of the oriented silicon steel decarburized plate reaches 0.6mm. Moreover, the measurement after single-point and multi-point correction can only guarantee the accuracy within the correction range, and its accuracy will deteriorate beyond the correction range. Summary of the invention

[0005] In view of the deficiencies of the prior art, the present invention discloses a method for measuring the oxygen content of an oxide layer in oriented silicon steel.

[0006] The technical solution adopted by the present invention is as follows:

[0007] A method for measuring the oxygen content of an oxide layer in oriented silicon steel comprises the following steps:

[0008] Step S1, sample preparation: prepare at least two samples;

[0009] Step S2, detection, comprising:

[0010] The first step: measure the total oxygen content of a sample and record it as Ototal;

[0011] The second step: sputter another sample to determine the Si content of the sample;

[0012] Step S3, data processing, includes:

[0013] The first step: draw the Si content curve. The position where the Si content reaches equilibrium is the total thickness of the oxide layer H. 总 The area close to the decarburized plate surface and with Si content below the Si equilibrium line is the outer oxide layer thickness H 外 , H 内 =H 总 -H 外 ;

[0014] The second step: draw the O content curve, based on H 外 is the dividing point, and the integral area of ​​the O content curve on its left is S 外 , the integral area of ​​the O content curve on the right is S 内 ;

[0015] The third step: Calculate the inner oxide layer O based on the measured total O content 内 =O 总 *S 内 / (S 内 +S 外 ).

[0016] Further, in the second step of step S2, the time t of the sputtering detection is based on O 总 Determine, t = 0.155e(O 总 / 200)*42+60.

[0017] Furthermore, in the second step of step S2, the sputtering power is set to 27W.

[0018] Further, in step S1, the sample types include flake samples and debris samples.

[0019] Further, in step S1, the size range of the sheet sample is: 50-150 mm in length and 50-150 mm in width.

[0020] Furthermore, in step S1, the flatness of the sheet sample is within 200 μm.

[0021] Furthermore, in step S1, the plane of the sheet sample is wiped clean with anhydrous ethanol.

[0022] Furthermore, in step S1, the debris sample is ultrasonically cleaned using anhydrous ethanol and then blow-dried.

[0023] Furthermore, in the first step of step S2, the detection instrument is an O and N analyzer.

[0024] Furthermore, in the second step of step S2, the detection instrument is a glow discharge spectrometer.

[0025] The beneficial effects of the present invention are as follows:

[0026] 1. Since the oxide layer of oriented silicon steel mainly includes Fe, O, Si, Mn and other elements, among which O and Si elements are enriched in the oxide layer, and the oxide layer is divided into inner oxide layer and outer oxide layer, and the Si content in the inner oxide layer is relatively low, the O and Si contents of the sample elements are measured by O and N analyzers, and the total oxide layer thickness is detected by sputtering. The O content curve and Si content curve are drawn according to the data. The area surrounded by the O content curves of the inner and outer oxide layers is Sinside and Soutside. By calculating the proportion of the inner and outer oxide layers, and then according to the total O content, the relative ratio of the O element content of the inner and outer oxide layers can be calculated, and finally the oxygen content of the inner oxide layer is calculated, and the result is accurate with small error.

[0027] 2. Since the main component of the outer oxide layer is Fe x O y The main component of the inner oxide layer is SiO2 embedded in the iron matrix. The main difference is the Si content. The part close to the surface of the steel plate and with a Si content less than that in the matrix is ​​the outer oxide layer. The total oxide layer thickness can be measured using a glow discharge spectrometer. The outer oxide layer thickness can then be determined using the Si content curve to accurately calculate the inner oxide layer thickness H. 内 =H 总 -H 外 .

[0028] 3. According to H 内 and H 外 , the O content curve is divided into two integral areas. The ratio of the inner oxide layer integral area to the total oxide layer integral area corresponds to the total oxygen content, and the oxygen content of the inner oxide layer can be directly obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the integrated area under the O content curve of the inner and outer oxide layers of Example 1.

[0030] Figure 2 Schematic diagram of the integrated area under the O content curve of the inner and outer oxide layers of Example 2.

[0031] Figure 3 Schematic diagram of the integrated area under the O content curve of the inner and outer oxide layers of Example 3.

[0032] Figure 4 Schematic diagram of the integrated area under the O content curve of the inner and outer oxide layers of Example 4. DETAILED DESCRIPTION

[0033] Embodiment 1:

[0034] A method for measuring the oxygen content of an oxide layer in oriented silicon steel comprises the following steps:

[0035] Step S1, sample preparation: prepare two samples. One sample is a sheet sample with a size range of length (50-150 mm)*width (50-150 mm). The sample surface is required to be flat with a flatness requirement within 200 μm, and the sample surface is wiped clean with anhydrous ethanol. The other sample is a debris sample, and the debris is ultrasonically cleaned with anhydrous ethanol, taken out and quickly dried with cold air from a hair dryer.

[0036] Step S2, detection, comprising:

[0037] The first step: weigh 0.2g of the chip sample and put it into the O and N analyzer to measure its total oxygen content O 全 =639ppm. The O and N analyzer model used was LECO-ON836.

[0038] The second step: Place the sheet sample in a glow discharge spectrometer for sputtering detection to measure the Si content and O content of the sample. The sputtering power is set to 27W, and the sputtering time t is determined according to the total O content to ensure that the sputtering depth is greater than the oxide layer thickness: t = 0.155e (O全 / 200) ×42+60=220s. The model of the glow discharge spectrometer is GD-PROFILER2.

[0039] Step S3, data processing, includes:

[0040] The first step: draw the Si content curve, such as Figure 1 As shown in the figure, when the Si content curve approaches a straight line, the Si content at that position reaches equilibrium, and the dotted line is used as the Si equilibrium line. When the Si content reaches equilibrium, the corresponding horizontal axis is considered to be the total thickness of the oxide layer H 总 =3.2μm. The intersection of the Si content curve and the Si equilibrium line closest to the origin of the coordinate is the decomposition point. The area on the left side close to the decarburized plate surface and with Si content below the Si equilibrium line is considered to be the outer oxide layer, and the other side is the inner oxide layer. The thickness of the outer oxide layer H 外 =0μm, and the other side is, and it is calculated that Hinside=Htotal-Houtside=3.2μm.

[0041] The second step: draw the O content curve, based on H 外 is the dividing point, and the integral area of ​​the O content curve on its left is S 外 , which corresponds to the outer oxide layer; the integral area of ​​the O content curve on the right is S 内, which corresponds to the inner oxide layer; The integral area of ​​the two regions is calculated using Origin software as S 内 =28.2 and S 外 =0.

[0042] The third step: Based on the measured total O content, the oxygen content of the inner oxide layer is calculated: O 内 =O 全 *S / (S 内 +S 外 )=639ppm.

[0043] Embodiment 2:

[0044] A method for measuring the oxygen content of an oxide layer in oriented silicon steel comprises the following steps:

[0045] Step S1, sample preparation: prepare two samples. One sample is a sheet sample with a size range of length (50-150 mm)*width (50-150 mm). The sample surface is required to be flat with a flatness requirement within 200 μm, and the sample surface is wiped clean with anhydrous ethanol. The other sample is a debris sample, and the debris is ultrasonically cleaned with anhydrous ethanol, taken out and quickly dried with cold air from a hair dryer.

[0046] Step S2, detection, comprising:

[0047] The first step: weigh 0.2g of the chip sample and put it into the O and N analyzer to measure its total oxygen content O 全 =687ppm. The O and N analyzer model used was LECO-ON836.

[0048] The second step: Place the sheet sample in a glow discharge spectrometer for sputtering detection to determine the Si content and O content of the sample. The sputtering power is set to 27W, and the sputtering time t is set according to the O 全 To ensure that the sputtering depth is greater than the oxide layer thickness: t = 0.155e (O全 / 200) ×42+60=262s. The model of the glow discharge spectrometer is GD-PROFILER2.

[0049] Step S3, data processing, includes:

[0050] The first step: draw the Si content curve, such as Figure 2 As shown in the figure, when the Si content curve approaches a straight line, the Si content at that position reaches equilibrium, and the dotted line is used as the Si equilibrium line. When the Si content reaches equilibrium, the corresponding horizontal axis is considered to be the total thickness of the oxide layer H 总=6.2μm. The intersection of the Si content curve and the Si equilibrium line closest to the coordinate origin is the decomposition point. The area on the left close to the decarburized plate surface and with Si content below the Si equilibrium line is considered to be the outer oxide layer, and the other side is the inner oxide layer. The thickness of the outer oxide layer H 外 =0.3μm, and on the other side is, it is calculated that Hinside=Htotal-Houtside=5.9μm.

[0051] The second step: draw the O content curve, with Hout as the dividing point, and the integral area of ​​the O content curve on its left is S 外 , which corresponds to the outer oxide layer; the integral area of ​​the O content curve on the right is S 内 , which corresponds to the inner oxide layer; The integral area of ​​the two regions is calculated using Origin software as S 内 =27.6 and S 外 =3.5.

[0052] The third step: Based on the measured total O content, the oxygen content of the inner oxide layer is calculated: O 内 =O 全 *S / (S 内 +S 外 )=609ppm.

[0053] Embodiment 3:

[0054] A method for measuring the oxygen content of an oxide layer in oriented silicon steel comprises the following steps:

[0055] Step S1, sample preparation: prepare two samples. One sample is a sheet sample with a size range of length (50-150 mm)*width (50-150 mm). The sample surface is required to be flat with a flatness requirement within 200 μm, and the sample surface is wiped clean with anhydrous ethanol. The other sample is a debris sample, and the debris is ultrasonically cleaned with anhydrous ethanol, taken out and quickly dried with cold air from a hair dryer.

[0056] Step S2, detection, comprising:

[0057] The first step: weigh 0.2g of the chip sample and put it into the O and N analyzer to measure its total oxygen content O 全 = 800ppm. The O and N analyzer model used is LECO-ON836.

[0058] The second step: Place the sheet sample in a glow discharge spectrometer for sputtering detection to determine the Si content and O content of the sample. The sputtering power is set to 27W, and the sputtering time t is set according to the O 全 To ensure that the sputtering depth is greater than the oxide layer thickness: t = 0.155e (O全 / 200) ×42+60=415s. The model of the glow discharge spectrometer is GD-PROFILER2.

[0059] Step S3, data processing, includes:

[0060] The first step: draw the Si content curve, such as Figure 3 As shown in the figure, when the Si content curve approaches a straight line, the Si content at that position reaches equilibrium, and the dotted line is used as the Si equilibrium line. When the Si content reaches equilibrium, the corresponding horizontal axis is considered to be the total thickness of the oxide layer H 总 =4.3μm. The intersection of the Si content curve and the Si equilibrium line closest to the origin of the coordinate is the decomposition point. The area on the left side close to the decarburized plate surface and with Si content below the Si equilibrium line is considered to be the outer oxide layer, and the other side is the inner oxide layer. The thickness of the outer oxide layer H 外 =0.45μm, and on the other side is, it is calculated that Hinside=Htotal-Houtside=3.85μm.

[0061] The second step: draw the O content curve, with Hout as the dividing point, and the integral area of ​​the O content curve on its left is S 外 , which corresponds to the outer oxide layer; the integral area of ​​the O content curve on the right is S 内 , which corresponds to the inner oxide layer; The integral area of ​​the two regions is calculated using Origin software as S 内 =29.1 and S 外 =26.6.

[0062] The third step: Based on the measured total O content, the oxygen content of the inner oxide layer is calculated: O 内 =O 全 *S / (S 内 +S 外 )=418ppm.

[0063] Embodiment 4:

[0064] A method for measuring the oxygen content of an oxide layer in oriented silicon steel comprises the following steps:

[0065] Step S1, sample preparation: prepare two samples. One sample is a sheet sample with a size range of length (50-150 mm)*width (50-150 mm). The sample surface is required to be flat with a flatness requirement within 200 μm, and the sample surface is wiped clean with anhydrous ethanol. The other sample is a debris sample, and the debris is ultrasonically cleaned with anhydrous ethanol, taken out and quickly dried with cold air from a hair dryer.

[0066] Step S2, detection, comprising:

[0067] The first step: weigh 0.2g of the chip sample and put it into the O and N analyzer to measure its total oxygen content O 全 =600ppm. The O and N analyzer model used is LECO-ON836.

[0068] The second step: Place the sheet sample in a glow discharge spectrometer for sputtering detection to determine the Si content and O content of the sample. The sputtering power is set to 27W, and the sputtering time t is set according to the O 全 To ensure that the sputtering depth is greater than the oxide layer thickness: t = 0.155e (O全 / 200) ×42+60=190s. The model of the glow discharge spectrometer is GD-PROFILER2.

[0069] Step S3, data processing, includes:

[0070] The first step: draw the Si content curve, such as Figure 4 As shown in the figure, when the Si content curve approaches a straight line, the Si content at that position reaches equilibrium, and the dotted line is used as the Si equilibrium line. When the Si content reaches equilibrium, the corresponding horizontal axis is considered to be the total thickness of the oxide layer H 总 =6.2μm. The intersection of the Si content curve and the Si equilibrium line closest to the coordinate origin is the decomposition point. The area on the left close to the decarburized plate surface and with Si content below the Si equilibrium line is considered to be the outer oxide layer, and the other side is the inner oxide layer. The thickness of the outer oxide layer H 外 =0.8μm, and on the other side is, and it is calculated that Hinside=Htotal-Houtside=5.4μm.

[0071] The second step: draw the O content curve, with Hout as the dividing point, and the integral area of ​​the O content curve on its left is S 外 , which corresponds to the outer oxide layer; the integral area of ​​the O content curve on the right is S 内 , which corresponds to the inner oxide layer; The integral area of ​​the two regions is calculated using Origin software as S 内 =69.3 and S 外 =128.

[0072] The third step: Based on the measured total O content, the oxygen content of the inner oxide layer is calculated: O 内 =O 全 *S / (S 内 +S 外 )=389ppm.

[0073] Comparison of test results:

[0074] Table 1: Comparison of data of embodiments.

[0075]

[0076]

[0077] Result analysis:

[0078] 1. By comparing the data in Table 1, it can be seen from Examples 1 and 2 that some silicon steel decarburization plates have an outer oxide layer and some silicon steel decarburization plates do not have an oxide layer;

[0079] 2. By comparing the data in Table 1, the O 全 and O 内 It can be seen that although O 全 >550ppm, but O 内 <550ppm, which means that it is inaccurate to use O total to judge whether the O content meets the requirements.

[0080] 3. By comparing the data in Table 1, the sample O in Example 3 全 >Example 2 O 全 , but in Example 3 内 <O in Example 2 内 , which shows that it is inaccurate to use O2 to judge that a sample has a higher O2 content.

[0081] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be within the scope of this specification.

[0082] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for measuring the oxygen content of the oxide layer in oriented silicon steel, characterized in that: The following steps are involved: Step S1, sample preparation: prepare at least two samples; Step S2, detection, comprising: The first step is to test the total oxygen content of a sample and record it as O 总 ; The second step: sputter another sample to determine the Si content of the sample; In the second step of step S2, the time t of the sputtering detection is based on O 总 OK, t = 0.155e (O总 / 200) ×42+60; Step S3, data processing, includes: The first step: draw the Si content curve. The position where the Si content reaches equilibrium is the total thickness of the oxide layer H. 总 The area close to the decarburized plate surface and with Si content below the Si equilibrium line is the outer oxide layer thickness H 外 , H 内 =H 总 -H 外 ; The second step: draw the O content curve, based on H 外 is the dividing point, and the integral area of ​​the O content curve on its left is S 外 , the integral area of ​​the O content curve on the right is S 内 ; The third step: Calculate the oxygen content of the inner oxide layer based on the measured total O content 内 =O 总 *S 内 / (S 内 +S 外 ).

2. The method for measuring the oxygen content of the inner oxide layer of oriented silicon steel according to claim 1, characterized in that: In the second step of step S2, the sputtering power is set to 27W.

3. The method for measuring the oxygen content of the inner oxide layer of oriented silicon steel according to claim 1, characterized in that: In step S1 , the sample types include flake samples and debris samples, the debris samples are subjected to total oxygen content detection, and the flake samples are subjected to sputtering detection.

4. The method for measuring the oxygen content of the inner oxide layer of oriented silicon steel according to claim 3, characterized in that: In step S1 , the size range of the sheet sample is: 50 to 150 mm in length and 50 to 150 mm in width.

5. The method for measuring the oxygen content of the inner oxide layer of oriented silicon steel according to claim 3, characterized in that: In step S1 , the flatness of the sheet sample is within 200 μm.

6. The method for measuring the oxygen content of the inner oxide layer of oriented silicon steel according to claim 3, characterized in that: In step S1 , a chip sample weighing 0.2 g is weighed.

7. The method for measuring the oxygen content of the inner oxide layer of oriented silicon steel according to claim 1, characterized in that: In step S1, the chip sample is ultrasonically cleaned using anhydrous ethanol and then blow-dried.

8. The method for measuring the oxygen content of the inner oxide layer of oriented silicon steel according to claim 1, characterized in that: In the first step of step S2, the detection instrument is an O and N analyzer.

9. The method for measuring the oxygen content of the inner oxide layer of oriented silicon steel according to claim 1, characterized in that: In the second step of step S2, the detection instrument is a glow discharge spectrometer.

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