Apparatus and method for electrochemically evaluating oxide layer of oriented silicon steel

Abstract

The application discloses a device and method for electrochemically evaluating an oxidation layer of oriented silicon steel, which comprises an electrolytic cell, a magnet group arranged on one side of the electrolytic cell, a saturated calomel electrode and a platinum electrode arranged on the electrolytic cell, and an electrochemical workstation connected with the electrolytic cell; the magnet group comprises fixed magnets fixed on the electrolytic cell and movable magnets magnetically connected with the fixed magnets, and the movable magnets are arranged on the outlet of the side surface of the electrolytic cell; the reference electrode is arranged between the magnet group and the auxiliary electrode; and the reference electrode and the auxiliary electrode are connected with the electrochemical workstation. The evaluation method of the application calculates the dissolution electric quantity of each layer of the oxidation layer of the oriented silicon steel by electrochemically measuring the potential-time curve of the oriented silicon steel sample, realizes the rapid and accurate determination of each layer of the oxidation layer of the oriented silicon steel, and can distinguish the performance of the Mg2SiO4 glass film bottom layer, the SiN layer, the SiO2 layer, the FeO layer and the fayalite layer, thereby providing guidance for the control of the production process parameters of the oriented silicon steel.

Description

Technical Field

[0001] This invention relates to the field of silicon steel coating technology, and in particular to an apparatus and method for electrochemically evaluating the oxide layer of oriented silicon steel. Background Technology

[0002] Grain-oriented silicon steel exhibits excellent magnetic properties along the rolling direction and is primarily used in the cores of power transformers. Therefore, grain-oriented silicon steel must possess a uniform and consistent insulating surface layer. The quality of this insulating surface layer is closely related to the quality of the magnesium oxide coating on the grain-oriented silicon steel surface. The production process of grain-oriented silicon steel is complex and has a long production cycle. The key steps involved in ensuring the quality of the magnesium oxide coating include: cold rolling—decarburization annealing—nitriding—MgO coating—high-temperature annealing—leveling and stretching annealing—and coating with an insulating layer. Specifically, the steel strip surface undergoes decarburization annealing to form a dense and uniform thin-film oxide layer primarily composed of SiO2 and Fe2SiO4. This layer has a three-layer structure: the outermost layer is a layer of FeO and fir olivine tens of nanometers thick; the middle layer is spherical SiO2; and the layer closest to the substrate is plated SiO2. Subsequently, the steel strip undergoes nitriding, utilizing ammonia gas to release active N atoms that react with Si in the substrate to form a SiN layer. Finally, the steel strip is coated with MgO under high-temperature conditions to form a magnesium silicate Mg2SiO4 glass film underlayer. Thus, it is evident that the oxide layer of grain-oriented silicon steel has a multi-layer structure. Therefore, it is extremely important to quickly and accurately detect the properties of each layer structure in the oxide layer of oriented silicon steel, which has important guiding value for the rational control of process parameters of oriented silicon steel.

[0003] Currently, the main method for evaluating the performance of the oxide layer of grain-oriented silicon steel is to indirectly evaluate its performance by chemically determining the content of substances such as SiO2, FeO, and Fe in the oxide layer. For example, Chinese patent CN 102706859 B discloses a method for determining silicon dioxide in the oxide layer of silicon steel. This method involves a series of treatments, including electrolysis, acid melting, and alkali washing, to destroy or dissolve unstable oxide inclusions in the anolyte residue, thereby separating SiO2 from other oxide inclusions. The stable anolyte residue is then melted in a muffle furnace, cooled, and leached with dilute nitric acid. The Si content is then determined using an ICP spectrometer and finally converted to SiO2 content. Another example is publication CN 102628848 A, which discloses a method for determining the iron content in the oxide layer of silicon steel. This method involves mixing an acidic corrosive agent capable of dissolving iron oxides on the silicon steel surface with a protective agent that inhibits corrosion of the silicon steel substrate, and water to prepare an H2O solution. + A corrosion inhibitor solution with an ion concentration range of 2.0–6.5 mol / L is used to immerse the silicon steel to be tested in the corrosion inhibitor solution. The corrosion inhibitor solution is used to corrode the iron oxide on the surface of the silicon steel to be tested until bubbles are observed. The silicon steel to be tested is then removed, and the iron content in the corrosion inhibitor solution after the corrosion reaction is detected, thus obtaining the iron content data in the oxide layer on the surface of the silicon steel.

[0004] The above chemical methods are relatively complicated and can only measure the content of a single substance in the oxide layer, and cannot quickly and accurately detect the oxide layer of oriented silicon steel with different compositions. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide an apparatus and method for electrochemically evaluating the oxide layer of oriented silicon steel, enabling rapid determination of each layer of the oxide layer in oriented silicon steel, and providing guidance for controlling the production process parameters of oriented silicon steel.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A first aspect of the present invention provides an apparatus for electrochemically evaluating the oxide layer of oriented silicon steel, comprising an electrolytic cell, a magnet assembly disposed on one side of the electrolytic cell, a saturated calomel electrode and a platinum electrode disposed on the electrolytic cell, and an electrochemical workstation connected to the electrolytic cell;

[0008] The electrolytic cell has an outlet on its side;

[0009] The magnet assembly includes a fixed magnet fixed on the electrolytic cell and a movable magnet magnetically connected to the fixed magnet, wherein the movable magnet is disposed on the outlet on the side of the electrolytic cell;

[0010] The saturated calomel electrode is positioned between the magnet assembly and the platinum electrode; the saturated calomel electrode and the platinum electrode are respectively connected to the electrochemical workstation.

[0011] Preferably, the electrolytic cell is made of plexiglass.

[0012] Preferably, the electrochemical workstation is equipped with a working electrode, a reference electrode, and an auxiliary electrode. The working electrode is connected to the silicon steel sample, the reference electrode is connected to the saturated calomel electrode, and the auxiliary electrode is connected to the platinum electrode.

[0013] A second aspect of the present invention provides a method for electrochemically evaluating the oxide layer of oriented silicon steel, comprising the following steps:

[0014] (1) Prepare three parallel samples of oriented silicon steel;

[0015] (2) Perform electrochemical measurements on the sample and plot the potential-time curve of the sample;

[0016] (3) The oxide layer of the sample is evaluated based on the potential-time curves of the three samples.

[0017] Preferably, step (1) includes cutting three parallel samples of oriented silicon steel, grinding one corner of the sample to reveal the substrate, and cleaning and drying the sample.

[0018] Preferably, the cleaning process uses anhydrous ethanol for cleaning.

[0019] Preferably, step (2) employs the apparatus for electrochemically evaluating the oxide layer of oriented silicon steel as described in the first aspect of the present invention, and the specific steps are as follows:

[0020] (2.1) Press the sample against the fixed magnet, and press the sample against the movable magnet;

[0021] (2.2) The prepared acidic test solution is introduced into the electrolytic cell, and the liquid level is controlled to exceed the height of the sample;

[0022] (2.3) Connect the sample to the working electrode of the electrochemical workstation, connect the saturated calomel electrode to the reference electrode of the electrochemical workstation, connect the platinum electrode to the auxiliary electrode of the electrochemical workstation, apply a constant current, measure and plot the potential and time curve of the sample, and end the test after 20 minutes.

[0023] Preferably, in step (2.2), the acidic test solution is prepared with 1-3 wt% H₂SO₄, 2-5 wt% NaCl, and deionized water; and / or

[0024] In step (2.2), the height of the acidic test solution exceeds the height of the sample by 3 cm; and / or

[0025] In step (2.3), the sample is polished to expose a corner of the substrate and connected to the working electrode of the electrochemical workstation; and / or

[0026] In step (2.3), the current density I of the constant current value is 1-5 mA / cm². 2 .

[0027] Preferably, in step (3), the dissolution charge Q of each layer of the oxide layer of the sample is calculated based on the potential-time curve of the sample. n for

[0028] Q n =I*(t) n -t n-1 )

[0029] In the formula, Q n The dissolution charge of each layer of the oxide layer in the sample is expressed in C.

[0030] I represents the current density of the constant current, in mA / cm². 2 ;

[0031] t nThis represents the time corresponding to the nth peak on the potential-time curve, in seconds.

[0032] t n-1 This represents the time corresponding to the (n-1)th peak on the potential-time curve, expressed in seconds.

[0033] Preferably, in step (3), the dissolution charge of each layer of the oriented silicon steel oxide layer is the average dissolution charge measured by three parallel samples.

[0034] The working principle of this invention is as follows: When grain-oriented silicon steel comes into contact with a test solution, its potential can be measured. This potential value is related to the surface material of the grain-oriented silicon steel; different materials correspond to different potential values. When a constant current is applied to the grain-oriented silicon steel, dissolution and peeling begin to occur on the surface. Since the oxide layer of the grain-oriented silicon steel has a multi-layered structure, the gradual dissolution and peeling of each layer leads to changes in the measured potential value. Therefore, it can be known that the peak value of the potential-time curve corresponds to the dissolution completion time of each layer of material in the oxide layer. The product of the corresponding time interval and the applied constant current I is the dissolution charge Q. n value.

[0035] The beneficial effects of this invention are as follows:

[0036] 1. The apparatus and method for electrochemically evaluating the oxide layer of oriented silicon steel of the present invention enables rapid and accurate determination of each layer of the oxide layer of oriented silicon steel, and can distinguish the layer properties of the Mg2SiO4 glass film bottom layer, SiN layer, spherical SiO2 layer, sheet SiO2 layer, FeO and fir olivine layer, etc., providing guidance for the control of process parameters in the production of oriented silicon steel.

[0037] 2. The electrochemical evaluation device of the present invention adopts a magnetic clamping method for the sample, which has the advantages of fast and simple sample clamping and can accurately carry out electrochemical testing of the oxide layer of oriented silicon steel. Attached Figure Description

[0038] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0039] Figure 1 This is a schematic diagram of the electrochemical evaluation device of the present invention;

[0040] Figure 2 This is a potential-time curve plotted for electrochemical measurements in this invention. Detailed Implementation

[0041] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way.

[0042] Combination Figure 1 As shown, the device for electrochemically evaluating the oxide layer of oriented silicon steel provided by the present invention includes an electrolytic cell 1, a magnet assembly, a saturated calomel electrode 5 and a platinum electrode 7, and an electrochemical workstation 6. The electrolytic cell 1 is made of transparent plexiglass material, which facilitates observation of the liquid level and the measurement process. The electrolytic cell 1 has a liquid inlet at the top and an outlet on the side. The magnet assembly is located at the outlet position on the side of the electrolytic cell 1, and includes a fixed magnet 3 installed on the side of the electrolytic cell 1 and a movable magnet 2 magnetically connected to the fixed magnet 3. The fixed magnet 3 is bonded to the periphery of the outlet on the side of the electrolytic cell 1, and the movable magnet 2 is located on the outlet on the side of the electrolytic cell 1. The setup facilitates the mounting of sample 4 on the side of electrolytic cell 1 and ensures that sample 4 is in contact with the acidic reaction solution in electrolytic cell 1, which is convenient for electrochemical measurements. A saturated calomel electrode 5 is mounted on electrolytic cell 1, with its upper part extending out of the cell and connected to the reference electrode of electrochemical workstation 6, and its lower part extending into the interior of electrolytic cell 1. A platinum electrode 7 is mounted on electrolytic cell 1 and connected to the auxiliary electrode of electrochemical workstation 6. The saturated calomel electrode 5 is positioned between the magnet assembly and the platinum electrode 7, ensuring that the lower end face of the saturated calomel electrode 5, the middle portion of the platinum electrode 7, and the outlet center on the side of electrolytic cell 1 are aligned (see [reference]). Figure 1 The electrochemical workstation 6 is equipped with a working electrode, a reference electrode, and an auxiliary electrode, wherein the working electrode is used to connect to the sample 4 placed between the magnet groups; the above-mentioned components can realize the electrochemical measurement of the sample 4 by installing the sample 4, adding the reaction solution to the electrolytic cell 1, and applying the current.

[0043] Based on the aforementioned apparatus for electrochemical evaluation of the oxide layer of grain-oriented silicon steel, the oxide layer of grain-oriented silicon steel is evaluated. The method includes the following steps:

[0044] (1) Preparation of three parallel oriented silicon steel samples 4: cut three parallel oriented silicon steel samples 4, grind one corner of the sample 4 to reveal the substrate, and clean and dry the sample 4.

[0045] The specific process is as follows: Cut three parallel samples 4 of oriented silicon steel, each with a size of 30mm×50mm. Use sandpaper to grind one corner of the long side to reveal the substrate. Clean the sample 4 with anhydrous ethanol and dry it before testing.

[0046] (2) Electrochemical measurements were performed on sample 4, and a potential-time curve of sample 4 was plotted. In a specific embodiment, an electrochemical evaluation device for the oxide layer of oriented silicon steel was used to perform electrochemical measurements on sample 4, which included the following steps:

[0047] (2.1) Secure the sample 4 to the fixed magnet 3, and use the movable magnet 2 to secure the sample 4;

[0048] The specific process is as follows: one side of the prepared sample 4 is attached to the fixed magnet 3, and the other side of the sample 4 is attached to the movable magnet 2. The sample 4 covers the outlet on the side of the electrolytic cell 1, thus completing the installation of the sample 4.

[0049] (2.2) The prepared acidic test solution is introduced into the electrolytic cell 1, and the liquid level is controlled to exceed the height of the sample 4.

[0050] The specific process is as follows: the acidic test solution is prepared by adding 1-3 wt% H2SO4, 2-5 wt% NaCl and deionized water. Then the prepared acidic test solution is poured into the electrolytic cell 1, and the liquid level is controlled to be 3 cm higher than the height of the sample 4.

[0051] (2.3) Connect sample 4 to the working electrode of electrochemical workstation 6, connect saturated calomel electrode 5 to the reference electrode of electrochemical workstation 6, connect platinum electrode 7 to the auxiliary electrode of electrochemical workstation 6, apply constant current, measure and plot the potential and time curve of sample 4, and end the test after 20 min.

[0052] The specific process is as follows: Connect one corner of the long side of sample 4 (i.e., the corner on sample 4 where the substrate has been ground out) to the working electrode (WE) of electrochemical workstation 6; connect the saturated calomel electrode 5 to the reference electrode (RE) of electrochemical workstation 6; and connect the platinum electrode 7 to the auxiliary electrode (CE) of electrochemical workstation 6; then set the current density I of the applied constant current to 1–5 mA / cm². 2 The potential-time curve of sample 4 was measured and plotted. The measurement was stopped after 20 minutes.

[0053] (3) The oxide layer of sample 4 was evaluated based on the potential-time curves of three parallel samples 4.

[0054] Specifically, the measured potential-time curve is as follows: Figure 2 As shown, the time corresponding to each curve peak is recorded as t. n -t n-1 Therefore, the dissolution charge Q of each layer of the oxide layer of the sample is first calculated based on the potential-time curve. n for

[0055] Q n =I*(t) n -t n-1 )

[0056] In the formula, Q n The dissolution charge of each layer of the oxide layer in the sample is expressed in C.

[0057] I represents the current density of the constant current, in mA / cm². 2 ;

[0058] t n This represents the time corresponding to the nth peak on the potential-time curve, in seconds.

[0059] t n-1 This represents the time corresponding to the (n-1)th peak on the potential-time curve, expressed in seconds.

[0060] Then, based on the Q measured in three parallel samples 4 n The average value of the results can be used to obtain the dissolution charge of each layer of the oxide layer of the oriented silicon steel.

[0061] The apparatus and method for electrochemically evaluating the oxide layer of oriented silicon steel of the present invention are further described below with reference to specific examples; the apparatus used in Examples 1 to 5 for electrochemically evaluating the oxide layer of oriented silicon steel includes: an electrolytic cell 1 made of transparent plexiglass, a fixed magnet 3 bonded to the periphery of the outlet on the side of the electrolytic cell 1, a movable magnet 2 magnetically connected to the fixed magnet 3, and a saturated calomel electrode 5 and a platinum electrode 7 fixed on the electrolytic cell 1.

[0062] Example 1

[0063] The grain-oriented silicon steel in this embodiment is batch #1 grain-oriented silicon steel;

[0064] Three parallel samples of oriented silicon steel from batch 1 were cut, each measuring 30mm × 50mm. The long side corner was sanded to reveal the substrate, and the samples were cleaned with anhydrous ethanol and dried before testing.

[0065] Secure one side of the sample to the fixed magnet, and then use the movable magnet to secure the other side of the sample to complete the sample installation. Prepare an acidic reaction solution using 1% H₂SO₄, 2% NaCl, and deionized water, and pour it into the electrolytic cell, ensuring the liquid level is 3 cm above the sample. Connect one long corner of the sample to the working electrode (WE) of the electrochemical workstation, the saturated calomel electrode to the reference electrode (RE), and the platinum electrode to the auxiliary electrode (CE). Set the current density I for applying the constant current to 1 mA / cm². 2 The measurement was started and a potential-time curve was plotted. The test ended after 20 minutes. The average dissolution charge Q1, Q2, Q3, Q4, and Q5 of each layer in the oriented silicon steel oxide layer were calculated to be 1.1 × 10⁻⁵. -4 C, 1.8×10 -4 C, 3.7×10 -4 C, 2.2×10 -4 C, 2.6×10 -4 C,

[0066] Q1, Q2, Q3, Q4, and Q5 correspond to the dissolution charge of the Mg2SiO4 glass bottom layer, SiN layer, FeO and fir olivine layer, spherical SiO2 layer, and plate-like SiO2 layer in the oriented silicon steel oxide layer, respectively.

[0067] Example 2

[0068] The grain-oriented silicon steel in this embodiment is batch #2 grain-oriented silicon steel;

[0069] Three parallel samples of oriented silicon steel from batch #2 were cut out, each measuring 30mm × 50mm. The long side corner was sanded to reveal the substrate, and the samples were cleaned with anhydrous ethanol and dried before testing.

[0070] Secure one side of the sample to the fixed magnet, and then use the movable magnet to secure the other side of the sample, completing the sample installation. Prepare an acidic reaction solution using a 2% H₂SO₄ solution, a 5% NaCl solution, and deionized water, and pour it into the electrolytic cell, ensuring the liquid level is 3 cm above the sample. Connect one long corner of the sample to the working electrode (WE) of the electrochemical workstation, the saturated calomel electrode to the reference electrode (RE), and the platinum electrode to the auxiliary electrode (CE). Set the current density I for applying the constant current to 2 mA / cm². 2 The measurement was started and a potential-time curve was plotted. The test ended after 20 minutes. The average dissolution charge Q1, Q2, Q3, and Q4 of each layer in the oriented silicon steel oxide layer were calculated to be 2.3 × 10⁻⁴. -4 C, 3.8×10 -4 C, 2.7×10 -4 C, 1.2×10 -4 C, where Q1, Q2, Q3, and Q4 correspond to the dissolution charge of the Mg2SiO4 glass underlayer, SiN layer, FeO and fir olivine layer, and SiO2 layer in the oriented silicon steel oxide layer, respectively.

[0071] Example 3

[0072] The grain-oriented silicon steel in this embodiment is batch #3 grain-oriented silicon steel;

[0073] Three parallel samples of grain-oriented silicon steel from batch #3 were cut out, each measuring 30mm × 50mm. The long side corner was sanded to reveal the substrate, and the samples were cleaned with anhydrous ethanol and dried before testing.

[0074] Secure one side of the sample to the fixed magnet, and then use the movable magnet to secure the other side of the sample, completing the sample installation. Prepare an acidic reaction solution using a 2% H₂SO₄ solution, a 4% NaCl solution, and deionized water, and pour it into the electrolytic cell, ensuring the liquid level is 3 cm above the sample. Connect one long corner of the sample to the working electrode (WE) of the electrochemical workstation, the saturated calomel electrode to the reference electrode (RE), and the platinum electrode to the auxiliary electrode (CE). Set the current density I for applying the constant current to 5 mA / cm². 2 The measurement was started and a potential-time curve was plotted. The test ended after 20 minutes. The average dissolution charge Q1, Q2, Q3, Q4, Q5, and Q6 of each layer in the oriented silicon steel oxide layer were calculated to be 3.6 × 10⁻⁶. -4 C, 1.5×10 -4 C, 3.1×10 -4 C, 3.2×10 -4 C, 2.1×10 -4 C, 2.5×10 -4 C, where Q1, Q2, Q3, Q4, Q5, and Q6 correspond to the dissolution charge of the Mg2SiO4 glass bottom layer, SiN layer, FeO layer, fir olivine layer, spherical SiO2 layer, and sheet-like SiO2 layer in the oriented silicon steel oxide layer, respectively.

[0075] Example 4

[0076] The grain-oriented silicon steel in this embodiment is batch #4 grain-oriented silicon steel;

[0077] Three parallel samples of oriented silicon steel from batch #4 were cut, each measuring 30mm × 50mm. The long side corner was sanded to reveal the substrate, and the samples were cleaned with anhydrous ethanol and dried before testing.

[0078] Secure one side of the sample to the fixed magnet, and then use the movable magnet to secure the other side of the sample, completing the sample installation. Prepare an acidic reaction solution using 1% H₂SO₄, 3% NaCl, and deionized water, and pour it into the electrolytic cell, ensuring the liquid level is 3 cm above the sample. Connect one long corner of the sample to the working electrode (WE) of the electrochemical workstation, the saturated calomel electrode to the reference electrode (RE), and the platinum electrode to the auxiliary electrode (CE). Set the current density I for applying the constant current to 4 mA / cm². 2 The measurement was started and the potential-time curve was plotted. The test ended after 20 minutes. The average dissolution charge Q1, Q2, and Q3 of each layer in the oxide layer of the grain-oriented silicon steel were calculated to be 1.2 × 10⁻³. -4 C, 2.8×10 -4 C, 3.1×10 -4C, where Q1, Q2, and Q3 correspond to the dissolution charge of the Mg2SiO4 glass substrate, FeO and fir olivine layer, and SiO2 layer in the oriented silicon steel oxide layer, respectively.

[0079] Example 5

[0080] The grain-oriented silicon steel used in this embodiment is batch #5 grain-oriented silicon steel;

[0081] Three parallel samples of oriented silicon steel from batch 5# were cut, each measuring 30mm × 50mm. The long side corner was sanded to reveal the substrate, and the samples were cleaned and dried with anhydrous ethanol before testing.

[0082] Secure one side of the sample to the fixed magnet, and then use the movable magnet to secure the other side of the sample, completing the sample installation. Prepare an acidic reaction solution using 3% H₂SO₄, 5% NaCl, and deionized water, and pour it into the electrolytic cell, ensuring the liquid level is 3 cm above the sample. Connect one long corner of the sample to the working electrode (WE) of the electrochemical workstation, the saturated calomel electrode to the reference electrode (RE), and the platinum electrode to the auxiliary electrode (CE). Set the current density I for applying the constant current to 3 mA / cm². 2 The measurement was started and the potential-time curve was plotted. The test ended after 20 minutes. The average dissolution charge Q1, Q2, Q3, and Q4 of each layer in the oriented silicon steel oxide layer were calculated to be 1.5 × 10⁻⁶. -4 C, 1.9×10 -4 C, 3.1×10 -4 C, 2.1×10 -4 C, where Q1, Q2, Q3, and Q4 correspond to the dissolution charge of the Mg2SiO4 glass underlayer, SiN layer, FeO and fir olivine layer, and SiO2 layer in the oriented silicon steel oxide layer, respectively.

[0083] In summary, the apparatus and method for electrochemically evaluating the oxide layer of oriented silicon steel of the present invention enables rapid and accurate determination of each layer of the oxide layer, distinguishing the properties of the Mg2SiO4 glass film bottom layer, SiN layer, SiO2 layer, FeO and fir olivine layer, providing guidance for the control of process parameters in the production of oriented silicon steel. The apparatus for electrochemically evaluating the oxide layer of oriented silicon steel uses a magnetic clamping method for the sample, which has the advantages of rapid and simple sample clamping and can accurately carry out electrochemical testing of the oxide layer of oriented silicon steel.

[0084] In summary, the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method of electrochemically evaluating an oxide layer of grain-oriented silicon steel, characterized by, The method comprises the following steps: (1) preparing three parallel samples of oriented silicon steel; (2) performing electrochemical measurement on the samples by using the device for evaluating the oxide layer of oriented silicon steel, and drawing the potential-time curve of the samples; The device for evaluating the oxide layer of oriented silicon steel comprises an electrolytic cell, a magnet group arranged on one side of the electrolytic cell, a saturated calomel electrode and a platinum electrode arranged on the electrolytic cell, and an electrochemical workstation connected with the electrolytic cell; The electrolytic cell is provided with an outlet on the side surface thereof; The magnet group comprises a fixed magnet fixed on the electrolytic cell and a movable magnet magnetically connected with the fixed magnet, and the movable magnet is arranged on the outlet on the side surface of the electrolytic cell; The saturated calomel electrode is arranged between the magnet group and the platinum electrode, and the saturated calomel electrode and the platinum electrode are respectively connected with the electrochemical workstation, The device for evaluating the oxide layer of oriented silicon steel performs electrochemical measurement on the samples, and draws the potential-time curve of the samples, and the specific steps are as follows: (2.1) tightly attaching the samples to the fixed magnet and the movable magnet; (2.2) introducing the prepared acid test solution into the electrolytic cell, and controlling the liquid level to be higher than the height of the samples; (2.3) connecting the samples with the working electrode of the electrochemical workstation, connecting the saturated calomel electrode with the reference electrode of the electrochemical workstation, and connecting the platinum electrode with the auxiliary electrode of the electrochemical workstation, then loading a constant current, measuring and drawing the potential-time curve of the samples, and ending the test after 20 minutes; (3) evaluating the oxide layer of the samples according to the potential-time curves of the three samples, calculating the dissolution electric quantity Q of each layer of the oxide layer of the sample according to the potential-time curve of the sample n to Q n = I * (t n - t n-1 ) wherein Q n is the dissolution charge of each layer of the oxide layer of the test sample, in C; I is the current density at constant current in mA / cm 2 ; t n tnis the time corresponding to the nth peak on the potential-time curve, in seconds; t n-1 tn-1is the time corresponding to the (n-1)th peak on the potential-time curve, in seconds, Each layer of the oxide layer of the samples comprises a Mg2SiO4 glass film bottom layer, a SiN layer, a spherical SiO2 layer, a flaky SiO2 layer, an FeO layer and an olivine layer.

2. The method of electrochemically evaluating the oxide layer of oriented silicon steel of claim 1, wherein, The electrolytic cell is made of organic glass.

3. The method of electrochemically evaluating the oxide layer of oriented silicon steel of claim 1 wherein, The electrochemical workstation is provided with a working electrode, a reference electrode and an auxiliary electrode, the working electrode is connected with the oriented silicon steel sample, the reference electrode is connected with the saturated calomel electrode, and the auxiliary electrode is connected with the platinum electrode.

4. The method of electrochemically evaluating the oxide layer of oriented silicon steel of claim 1 wherein, The step (1) comprises cutting three parallel samples of oriented silicon steel, polishing one corner of the samples as a base, and cleaning and drying the samples.

5. The method of electrochemically evaluating the oxide layer of oriented silicon steel of claim 4, wherein, In the step (1), the samples are cleaned by using anhydrous ethanol.

6. The method of electrochemically evaluating the oxide layer of oriented silicon steel of claim 1 wherein, In the step (2.2), the acid test solution is prepared by using 1-3wt% H2SO4, 2-5wt% NaCl and deionized water; and / or In the step (2.2), the height of the acid test solution is 3cm higher than the height of the samples; and / or In the step (2.3), the corner of the sample polished as the base is connected with the working electrode of the electrochemical workstation; and / or In the step (2.3), the current density I of the constant current value is 1 to 5 mA / cm 2 .

7. The method of electrochemically evaluating the oxide layer of oriented silicon steel of claim 6, wherein, In the step (3), the dissolution electric quantity of each layer of the oxide layer of the oriented silicon steel is the average value of the dissolution electric quantities measured by the three parallel samples.

Images