A method for controlling solidification structure of high-grade non-oriented silicon steel based on pulse current

Abstract

A method for controlling the solidification structure of high-grade non-oriented silicon steel based on pulse current control, comprising: selecting high-grade silicon steel alloy raw materials and adding rare earth elements; smelting molten steel in an electric arc furnace and monitoring the composition using an online analysis instrument; in the continuous casting process, using an adjustable pulse power supply to optimize the current frequency, amplitude and application time; using a machine learning model to predict defects and automatically adjust the process parameters; slowly discharging the furnace, using an intelligent cooling system to control the cooling speed, reduce thermal stress and reduce the risk of surface defects; then uniform heat treatment is carried out, using layered heating technology to ensure uniform internal structure; then heat the casting blank to hot rolling temperature, and then cold roll the hot rolled plate using gapless rolling technology, and then use nano coating technology for surface treatment. The present application significantly improves the corrosion resistance, wear resistance and oxidation resistance of the cold rolled plate through the nano coating technology, prolonging the service life.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of controlling the solidification structure of high-grade non-oriented silicon steel, and particularly relates to a method for controlling the solidification structure of high-grade non-oriented silicon steel based on pulse current. BACKGROUND

[0002] Electrical steel is mainly divided into oriented and non-oriented silicon steel, and the non-oriented silicon steel is further divided into low-grade, medium-grade and high-grade silicon steel, and the grade is generally related to the Si content of the steel grade. The low-grade non-oriented silicon steel has a phase change during rolling, and the requirement for the solidification structure of the casting blank is not high, while the high-grade non-oriented silicon steel has no phase change, and the surface quality of the finished product will be affected by the solidification structure of the casting blank. The higher the columnar grain rate of the casting blank, the higher the risk of corrugated defects on the surface of the high-grade non-oriented silicon steel. Therefore, in order to control the solidification structure of the high-grade non-oriented silicon steel, a method for controlling the solidification structure of high-grade non-oriented silicon steel based on pulse current is invented. SUMMARY

[0003] This section is intended to summarize some aspects of the embodiments of the present application and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of the specification of the present application in order to avoid obscuring the purpose of this section, the abstract and the title, and such simplifications or omissions cannot be used to limit the scope of the present application.

[0004] In view of the above or existing problems of the method for controlling the solidification structure of high-grade non-oriented silicon steel based on pulse current, the present application is proposed.

[0005] To solve the above technical problems, the present application provides the following technical solutions:

[0006] The embodiment of the present application provides a method for controlling the solidification structure of high-grade non-oriented silicon steel based on pulse current, which comprises: selecting high-grade silicon steel alloy raw materials and adding rare earth elements; smelting molten steel in an electric arc furnace, controlling chemical composition and temperature, and monitoring composition using an online analysis instrument; in the continuous casting process, using an adjustable pulse power supply, optimizing current frequency, amplitude and application time; monitoring the solidification of the casting blank in real time, analyzing the surface quality in combination with a computer vision system, predicting defects using a machine learning model and automatically adjusting process parameters; slowly discharging the furnace, using an intelligent cooling system, controlling the cooling speed, reducing thermal stress and reducing the risk of surface defects; then performing uniform heat treatment, using layered heating technology to ensure uniform internal structure; then heating the casting blank to hot rolling temperature, and then cold rolling the hot-rolled plate using gapless rolling technology, and then performing surface treatment using nano coating technology.

[0007] As a preferred scheme of the method for controlling solidification structure of high-grade non-oriented silicon steel based on pulse current control according to the present application, wherein: the high-grade silicon steel contains silicon in an amount of 3.0%-4.5% and iron in an amount of more than 95%.

[0008] As a preferred scheme of the method for controlling solidification structure of high-grade non-oriented silicon steel based on pulse current control according to the present application, wherein: the high-grade silicon steel alloy raw material is selected and rare earth elements are added, including: in the smelting process, the rare earth elements are added to the molten steel in the form of an alloy, and the temperature is controlled at 1500-1600°C when added to the molten steel, and the addition amount of the rare earth elements is 0.01%-0.5%.

[0009] As a preferred scheme of the method for controlling solidification structure of high-grade non-oriented silicon steel based on pulse current control according to the present application, wherein: the molten steel is smelted in an electric arc furnace, the chemical composition and temperature are controlled, and the composition is monitored using an online analysis instrument, including: the composition is monitored using a spectral analyzer, real-time chemical composition analysis is performed, including the content of carbon, silicon, manganese, phosphorus, sulfur and alloy elements, the sampling frequency is set to once per minute, the temperature and composition data are recorded in real time through a PLC system, and the in-furnace operation parameters are automatically adjusted according to the online analysis results.

[0010] As a preferred scheme of the method for controlling solidification structure of high-grade non-oriented silicon steel based on pulse current control according to the present application, wherein: in the re-continuous casting process, an adjustable pulse power source is used to optimize the current frequency, amplitude and application time, including: the current frequency is set to 300 Hz, the current amplitude is set to 600 A, 3 seconds of current is applied in the initial application stage, 17 seconds of static state is observed, 5 seconds of current is applied in the middle application stage, 15 seconds of static state is observed, the observation is continued, 10 seconds of current is applied in the final application stage, 10 seconds of static state is observed, and the solidification process is observed.

[0011] As a preferred scheme of the method for controlling solidification structure of high-grade non-oriented silicon steel based on pulse current control according to the present application, wherein: the machine learning model is used to predict defects and automatically adjust process parameters, including: a convolutional neural network is used to identify the type of defects, real-time image data is input into the trained convolutional neural network, defects are predicted, the model output is analyzed, and the type of defects and the risk level are determined; if the risk of surface cracks is predicted to increase, the system automatically reduces the current amplitude or adjusts the application time.

[0012] As a preferred scheme of the method for controlling solidification structure of high-grade non-oriented silicon steel based on pulse current control, the slow reheating is performed by using an intelligent cooling system to control the cooling speed, reduce thermal stress, and reduce the risk of surface defects, including: different cooling speeds are set according to different stages of the casting blank: the initial cooling is 0-20 s, the cooling rate is controlled to be 1 °C / s, the surface temperature of the casting blank is rapidly reduced; the medium-term cooling is 20-60 s, the cooling rate is controlled to be 0.5 °C / s, the thermal stress is reduced; the late cooling is more than 60 s, the cooling rate is controlled to be 0.2 °C / s, and the risk of surface defects is further reduced; and the temperature of the casting blank is ensured to be reduced to below 600 °C before demoulding.

[0013] As a preferred scheme of the method for controlling solidification structure of high-grade non-oriented silicon steel based on pulse current control, the uniform heat treatment is then performed by using a layered heating technology to ensure uniform internal structure, including: the layered heating is performed according to the height of the casting blank, and three layers are set: the first layer is set to have a heating temperature of 900 °C and a holding time of 30 min; the second layer is set to have a heating temperature of 850 °C and a holding time of 40 min; and the third layer is set to have a heating temperature of 800 °C and a holding time of 50 min.

[0014] As a preferred scheme of the method for controlling solidification structure of high-grade non-oriented silicon steel based on pulse current control, the casting blank is heated to a hot rolling temperature, and then cold rolling is performed on the hot-rolled plate by using a gapless rolling technology, including: the hot rolling temperature is set to be 1100-1300 °C, the heating time is 30 min-60 min, the hot rolling equipment is a multi-pass hot rolling machine, the rolling speed is set to be 1-5 m / min, the rolling number is 4-6 passes, and the thickness of the plate is checked after each pass; and the cold rolling temperature is kept at 25-300 °C, and the rolling speed is set to be 3-8 m / min, so that efficient cold rolling is ensured.

[0015] As a preferred scheme of the method for controlling solidification structure of high-grade non-oriented silicon steel based on pulse current control, after the cold rolling, the surface treatment is performed by using a nano-coating technology, including: the coating liquid is uniformly sprayed on the surface of the plate by using a spray gun, the spraying distance is 15-30 cm, the plate is immersed in the coating liquid for 1-5 min, the coated plate is placed in a well-ventilated environment for natural drying for 1-2 h, and then heat curing is performed by using an oven, the temperature is set to be 80-120 °C, and the time is 30-60 min.

[0016] The application has the beneficial effects that the nano-coating technology is used to significantly improve the corrosion resistance, wear resistance and oxidation resistance of the cold-rolled plate, and prolong the service life. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor. Among them:

[0018] Fig. 1 A process flow diagram of a method for controlling the solidification structure of high-grade non-oriented silicon steel based on pulse current is provided for the embodiments of the present application.

[0019] Fig. 2 A schematic diagram of the use of electric pulses of a method for controlling the solidification structure of high-grade non-oriented silicon steel based on pulse current is provided for the embodiments of the present application.

[0020] Fig. 3 A schematic diagram of the frequency and voltage of electric pulses of a method for controlling the solidification structure of high-grade non-oriented silicon steel based on pulse current is provided for the embodiments of the present application.

[0021] Reference signs: 1, electric pulse device; 2, crystallizer; 3, cast slab macrostructure. DETAILED DESCRIPTION

[0022] In order to make the above-mentioned purposes, features and advantages of the present application more apparent and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the drawings.

[0023] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application, but the present application can also be implemented in other ways different from those described herein, and those skilled in the art can make similar generalizations without departing from the connotation of the present application, therefore the present application is not limited to the specific embodiments disclosed below.

[0024] Secondly, the "one embodiment" or "embodiment" referred to herein means that the specific features, structures or characteristics can be included in at least one implementation of the present application. "In one embodiment" appearing in different places in the specification does not mean the same embodiment, nor is it an independent or alternative embodiment that excludes other embodiments.

[0025] Embodiment 1

[0026] Reference Figs. 1-3 For an embodiment of the present application, the embodiment provides a method for controlling the solidification structure of high-grade non-oriented silicon steel based on pulse current, comprising:

[0027] S1: Select high-grade silicon steel alloy raw materials and add rare earth elements.

[0028] Preferably, the high-grade silicon steel contains 3.0%-4.5% silicon and more than 95% iron. During the smelting process, the rare earth elements are added to the molten steel in the form of an alloy, and the temperature is controlled at 1500-1600°C when added to the molten steel. The addition amount of rare earth elements is 0.01%-0.5%.

[0029] Further, if the molten steel is 1000 kg, the addition amount is 0.1 kg (0.01%) to 5 kg (0.5%). Slowly pour the rare earth alloy into the molten steel to ensure uniform dispersion. The addition can be in the form of ingot, and the temperature is controlled at 1500-1600°C when added in batches to avoid drastic temperature fluctuations. Use a mechanical stirring device to keep the molten steel at 1500-1600°C for 5-10 minutes to promote the reaction of rare earth elements with the molten steel. Monitor the color and reaction state of the molten steel to ensure uniform distribution of alloy elements. After stirring is completed, take samples from the furnace for chemical composition analysis.

[0030] S2: Smelt the molten steel in an electric arc furnace, control the chemical composition and temperature, and monitor the composition using online analysis instruments.

[0031] Preferably, a spectrometer is used for composition monitoring, real-time chemical composition analysis, including the content of carbon, silicon, manganese, phosphorus, sulfur, and alloy elements, with a sampling frequency of once per minute. Temperature and composition data are recorded in real time through a PLC system. According to the online analysis results, automatically adjust the furnace operating parameters.

[0032] Further, according to the real-time data, the PLC system automatically adjusts the furnace operating parameters (such as heating power, alloy element addition amount):

[0033] If a certain element is low, the PLC automatically instructs to increase the addition amount of that element;

[0034] If a certain element exceeds the standard, the PLC automatically instructs to reduce the furnace temperature or change the heating strategy.

[0035] The operator can view the composition and temperature changes of the molten steel in real time through the monitoring interface. If the composition exceeds the set range, the PLC system issues an alarm to prompt the operator to take measures. Take samples from the molten steel every hour for laboratory analysis to verify the accuracy of the spectrometer analysis results.

[0036] S3: In the continuous casting process, an adjustable pulse power supply is used to optimize the current frequency, amplitude, and application time.

[0037] Preferably, the current frequency is set to 300 Hz, the current amplitude is set to 600 A, the initial application time is set to 3 seconds, the static time is set to 17 seconds, the temperature and flow state are observed, the middle application time is set to 5 seconds, the static time is set to 15 seconds, the observation continues, the final application time is set to 10 seconds, the static time is set to 10 seconds, and the solidification process is observed.

[0038] Further, the molten steel is heated to 1500-1600°C, it is ensured that the alloy and rare earth elements have fully reacted, the initial pulse current is applied: the current parameters are set as follows: frequency: 300 Hz, current amplitude: 600 A, application time: 3 seconds of pulse current is applied, and after the application of the current, it is static for 17 seconds, no current is applied, the flow state and temperature change of the molten steel are observed, an infrared temperature measuring instrument is used to monitor the surface and internal temperature of the molten steel, the temperature fluctuations are recorded, a camera is used to observe the flow of the molten steel, and whether the flowability of the molten steel changes after the application of the current is confirmed.

[0039] In the middle stage, the pulse current is applied: the current parameters remain unchanged: frequency: 300 Hz, current amplitude: 600 A, application time: 5 seconds of pulse current is applied, static time: 15 seconds after the application of the current, the temperature and flow state of the molten steel are continuously observed, whether the temperature significantly decreases or increases is monitored, the correlation between the temperature and the solidification trend is recorded, the surface fluctuation and flow trend of the molten steel are observed, and the influence of the pulse current on the flow state is confirmed.

[0040] In the final stage, the pulse current is applied: the current parameters remain unchanged: frequency: 300 Hz, current amplitude: 600 A, application time: 10 seconds of pulse current is applied, static time: 10 seconds after the application of the current, the solidification of the molten steel is observed, the temperature drop rate of the molten steel surface is monitored, the temperature gradient during the solidification process is particularly focused on, whether the flow of the molten steel slows down is observed, and whether the molten steel surface starts to solidify to form a solid layer is recorded.

[0041] S4: Real-time monitoring of the solidification of the casting blank, analysis of the surface quality combined with a computer vision system, prediction of defects using a machine learning model, and automatic adjustment of process parameters.

[0042] Preferably, a convolutional neural network is used to identify the defect type, real-time image data is input into the trained convolutional neural network for defect prediction, the model output is analyzed to determine the defect type and its risk level, and if the surface crack risk increases, the system automatically reduces the current amplitude or adjusts the application time.

[0043] Further, the camera captures high-resolution images of the billet surface in real-time and sends the images to the computer for processing through a high-speed data transmission channel. The acquisition frequency is 30 frames per second, ensuring that the image data covers the entire surface of the casting billet. The collected images are pre-processed, including denoising, grayscale, contrast enhancement, etc., to improve the recognition accuracy of the CNN model. The pre-processing algorithm runs within 100 milliseconds to ensure real-time processing of data. The pre-processed image data is input into the pre-trained CNN model, which has a hierarchical structure including convolutional layers, pooling layers, and fully connected layers. The model matches the identified features with the trained defect library, classifies the defect types, including cracks: surface crack risk, pores: possibility of pore formation during casting, scale: surface oxidation defects, corrugation defects: surface wave-shaped corrugation defects, and defect risk level assessment: risk assessment for each type of defect, with the model outputting a risk value between 0 and 1, indicating the severity of the defect.

[0044] Risk level: low risk (<0.3): no obvious defects on the surface, process remains unchanged; medium risk (0.3-0.7): slight defects on the surface, adjust current parameters appropriately; high risk (>0.7): severe surface defects, immediate process parameter adjustment required.

[0045] Crack risk detection: if the CNN model predicts that the surface crack risk is greater than 0.7, the system triggers the adjustment mechanism, reducing the current amplitude from 600 A to 500 A, reducing energy input and thermal stress.

[0046] Adjustment of current application time: adjust the current application time from 5 seconds to 3 seconds, and extend the resting time from 15 seconds to 20 seconds to gradually cool the molten steel and reduce the probability of crack formation. The system feeds back real-time images and defect detection results to the PLC control system. The PLC controller adjusts the frequency and application timing of the pulse power source based on the risk level signal to optimize the solidification process of the casting billet. The adjusted process parameters are applied in real-time to the next pulse current application cycle to ensure dynamic process response. Further image acquisition: after adjusting the process parameters, continue to collect images of the casting billet surface and input them into the CNN model for further detection to confirm whether the defects have been alleviated. If the model detects that the crack risk has decreased to below 0.3, the process adjustment stops; if the crack risk is still above 0.3, continue to adjust the process parameters until the risk is reduced to a safe range.

[0047] S5: Slowly out of the furnace, use an intelligent cooling system to control the cooling speed, reduce thermal stress, and reduce the risk of surface defects.

[0048] Preferably, different cooling speeds are set according to different stages of the casting billet:

[0049] Initial cooling 0-20s, control cooling rate at 1°C / s, rapidly reduce the slab surface temperature;

[0050] Medium-term cooling 20-60s, control cooling rate at 0.5°C / s, reduce thermal stress;

[0051] Late cooling 60s or more, control cooling rate at 0.2°C / s, further reduce the risk of surface defects; ensure the temperature of the slab is reduced to below 600°C before demoulding.

[0052] Further, set to 1°C / s, achieve rapid cooling through high-pressure water spraying and air cooling system. Use temperature sensors to monitor the slab surface temperature in real time, ensure that it is rapidly reduced from 1200°C to below 1000°C from the time of discharge. After the cooling system starts, the PLC controller controls the water flow rate and air volume of the cooling device according to the data feedback by the temperature sensor. Water spraying rate: control at 30 L / min, spray water temperature is 20°C, cover the slab surface evenly through multiple nozzles. Air cooling system air speed: set to 15 m / s, ensure uniform cooling process. Initial cooling time is 0-20 seconds, surface temperature should be reduced from 1200°C to about 1000°C.

[0053] Set to 0.5°C / s, control the stability of cooling, the temperature target of the medium-term stage is to further reduce from 1000°C to 800°C. After initial cooling, the PLC system reduces the spraying intensity and air cooling system air speed according to temperature sensor data. Water spraying rate: reduce to 15 L / min, spray water temperature remains unchanged, continue to spray evenly. Air cooling system air speed: reduce to 10 m / s, ensure uniform temperature drop of the slab surface and internal, prevent excessive thermal stress due to rapid cooling. Temperature should be reduced from 1000°C to 800°C within 20-60 seconds, the PLC system dynamically adjusts the cooling rate to ensure stable temperature drop within the target temperature range.

[0054] Set to 0.2°C / s, gradually cool down. The target temperature of the late cooling stage is to further reduce from 800°C to below 600°C, ensure the temperature meets the standard before demoulding. After the end of medium-term cooling, the PLC system further reduces the spraying and air cooling intensity, so that the slab gradually and evenly cools down in the late cooling. Water spraying rate: reduce to 5 L / min, water temperature remains at 20°C, ensure gentle cooling. Air cooling system air speed: reduce to 5 m / s, maintain stable cooling environment. Late cooling time is 60 seconds or more, temperature should be reduced from 800°C to below 600°C, ensure the slab does not produce cracks when demoulding.

[0055] S6: Then perform uniform heat treatment, use layered heating technology, ensure uniform internal structure.

[0056] Preferably, the slab is heated in layers according to its height, set to 3 layers:

[0057] The first layer is set to a heating temperature of 900°C and a holding time of 30 minutes;

[0058] The second layer is set to a heating temperature of 850°C and a holding time of 40 minutes;

[0059] The third layer is set to a heating temperature of 800°C and a holding time of 50 minutes.

[0060] Further, assuming the total height of the slab is 1200 mm, it is divided into 3 heating layers, each with a height of 400 mm, namely the first layer (0-400 mm), the second layer (400-800 mm), and the third layer (800-1200 mm).

[0061] In the bottom region of the slab (0-400 mm), the heating device is set to 900°C, and the heating rate of this region is adjusted by the multi-zone heating control equipment to ensure uniform heating. It is set to 5°C per minute to ensure gradual heating from room temperature to 900°C, avoiding excessive surface stress caused by rapid heating. After reaching 900°C, the temperature is kept stable for 30 minutes to ensure uniform temperature of this layer of slab. The temperature of the bottom region of the slab is monitored in real time by the PLC system to ensure uniformity. The data feedback by the temperature sensor is displayed in real time, and if the temperature deviation exceeds ±5°C, the PLC system automatically adjusts the power of the heating device to maintain the temperature within the target range.

[0062] The middle region (400-800 mm) is heated to 850°C, and the multi-zone heating equipment is controlled by the PLC system to gradually heat this region to 850°C. It is set to 4°C per minute to ensure slow heating of the middle region of the slab, ensuring that the internal structure does not generate excessive stress during the heating process. After reaching 850°C, the temperature is kept stable for 40 minutes to ensure uniform heat conduction to the interior of the slab. The temperature sensor is installed in the middle of the slab, and the temperature of this region is monitored in real time by the PLC system, and the data is also fed back to the controller. If the temperature deviation exceeds ±5°C, the system will automatically adjust the output power of the heater to ensure that the temperature of the middle layer is stable at 850°C.

[0063] The upper region (800-1200 mm) heating setting is 800°C, and the PLC system continues to control the heating equipment to slowly heat this region. The setting is 3°C per minute to ensure that the top of the casting blank slowly heats to 800°C, avoiding the concentration of thermal stress due to the rapid heating of the top region. After reaching 800°C, the temperature is kept stable for 50 minutes to ensure that the heat is evenly transferred to the uppermost layer of the entire casting blank. The temperature sensor installed in the top region monitors the temperature change through the PLC system, and if the temperature deviation exceeds ±5°C, the system automatically adjusts the heating intensity.

[0064] Ensure that the temperature in this region is 800°C for 50 minutes.

[0065] S7: The casting blank is heated to hot rolling temperature, and then the hot rolled plate is cold rolled using gapless rolling technology, and the surface is treated after cold rolling using nano coating technology.

[0066] Preferably, the hot rolling temperature is set to 1100-1300°C, the heating time is 30-60 minutes, the hot rolling equipment uses a multi-pass hot rolling mill, the rolling speed is set to 1-5 m / min, and the rolling number is 4-6 passes. The thickness of the plate is checked after each pass; the cold rolling rolling temperature is kept at 25-300°C, and the rolling speed is set to 3-8 m / min to ensure efficient cold rolling. The coating liquid is uniformly sprayed on the surface of the plate using a spray gun, the spraying distance is 15-30 cm, the plate is immersed in the coating liquid for 1-5 minutes; the coated plate is placed in a well-ventilated environment for natural drying for 1-2 hours, and then heat curing is performed using an oven, the temperature is set to 80-120°C, and the time is 30-60 minutes.

[0067] Application Example

[0068] A unidirectional pulse current is applied to the molten steel in the crystallizer, as described in detail in Fig. 1 , the high-frequency power supply 1 is connected to the 380V three-wire four-phase power air switch, and 2-4 cables with a cross section of ≥10 mm2 are connected; the output negative pole of the high-frequency power supply is connected to the roller 3 of the magnetic force rectifier through 2-4 cables with a cross section of ≥100 mm2, and the output positive pole of the high-frequency power supply is connected to the molten steel in the crystallizer 2 through 2-4 cables with a cross section of ≥100 mm2 and an electrode connector, as shown in Fig. 1 ; during operation, the electrode is baked to a red state, the high-frequency power supply switch is turned on, the electrode is inserted into the molten steel in the crystallizer at a depth of 10-400 cm, and the electrode is fixed; through the rectifier device, the positive pulse current is filtered out, the negative pulse current is retained, the voltage is adjusted to -30-0V, the voltage frequency diagram is shown in Fig. 2 , the current is adjusted to 0-2000A, and the frequency is adjusted to 1-100HZ. After production is completed, the high-frequency power supply switch is turned off, and the electrode is removed from the crystallizer.

[0069] It should be noted that the above examples are only used to illustrate the technical solutions of the present application but not to limit the present application. Although the present application is described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or equivalently replaced, without departing from the spirit and scope of the technical solutions of the present application, which should be covered in the scope of the claims of the present application.

Claims

1. A method for controlling the solidification structure of high-grade non-oriented silicon steel based on pulsed current, characterized in that, include: High-grade silicon steel alloy raw materials are selected, and rare earth elements are added; Molten steel is smelted in an electric arc furnace, with control over chemical composition and temperature, and the composition is monitored using online analytical instruments. In the recasting process, an adjustable pulse power supply is used to optimize the current frequency, amplitude, and application time; Real-time monitoring of the solidification of the billet, combined with computer vision system analysis of surface quality, and machine learning model prediction of defects and automatic adjustment of process parameters; Then, it is slowly removed from the furnace, using an intelligent cooling system to control the cooling rate, reduce thermal stress, and minimize the risk of surface defects. Then, a uniform heat treatment is performed, using layered heating technology to ensure a uniform internal structure; The billet is then heated to the hot rolling temperature, and then the hot-rolled sheet is cold-rolled using gapless rolling technology. After cold rolling, the surface is treated using nano-coating technology. High-grade silicon steel contains 3.0%-4.5% silicon and over 95% iron. The selected high-grade silicon steel alloy raw material, with the addition of rare earth elements, includes: During the smelting process, rare earth elements are added to the molten steel in alloy form. The temperature is controlled at 1500-1600℃ when adding the rare earth elements, and the amount of rare earth elements added is 0.01%-0.5%. The method of using machine learning models to predict defects and automatically adjust process parameters includes: The system uses a convolutional neural network to identify defect types. Real-time image data is input into the trained convolutional neural network to predict defects. The model output is analyzed to determine the defect type and its risk level. If an increased risk of surface cracks is predicted, the system automatically reduces the current amplitude or adjusts the application time. The process then involves uniform heat treatment using a layered heating technique to ensure a uniform internal structure, including: Heating is performed in three layers based on the height of the cast billet. The first layer is the bottom area of ​​the billet, the second layer is the middle area of ​​the billet, and the third layer is the upper area of ​​the billet. The first layer is set to a heating temperature of 900℃ and a holding time of 30 minutes. The second layer is set to a heating temperature of 850℃ and a holding time of 40 minutes. The third layer is set to a heating temperature of 800℃ and a holding time of 50 minutes. The surface treatment using nano-coating technology after cold rolling includes: Use a spray gun to evenly spray the coating liquid onto the surface of the board at a distance of 15-30cm. Immerse the board in the coating liquid for 1-5 minutes. Place the coated board in a well-ventilated environment to air dry naturally for 1-2 hours. Then use an oven for heat curing at a temperature of 80-120℃ for 30-60 minutes.

2. The method for controlling the solidification structure of high-grade non-oriented silicon steel based on pulsed current as described in claim 1, characterized in that, The process of melting molten steel in an electric arc furnace, controlling the chemical composition and temperature, and monitoring the composition using online analytical instruments includes: Composition monitoring is performed using a spectrometer, and real-time chemical composition analysis is conducted, including the content of carbon, silicon, manganese, phosphorus, sulfur, and alloying elements. The sampling frequency is set to once per minute. Temperature and composition data are recorded in real time through a PLC system, and the furnace operating parameters are automatically adjusted based on the online analysis results.

3. The method for controlling the solidification structure of high-grade non-oriented silicon steel based on pulsed current as described in claim 1, characterized in that, In the recasting process, an adjustable pulse power supply is used to optimize the current frequency, amplitude, and application time, including: Set the current frequency to 300Hz and the current amplitude to 600A. Apply the current for 3 seconds at the beginning of the application, let it stand for 17 seconds, and observe the temperature and flow state. Apply the current for 5 seconds at the middle of the application, let it stand for 15 seconds, and continue to observe. Apply the current for 10 seconds at the end of the application, let it stand for 10 seconds, and observe the solidification process.

4. The method for controlling the solidification structure of high-grade non-oriented silicon steel based on pulsed current as described in claim 1, characterized in that, The process of heating the billet to the hot rolling temperature and then cold rolling the hot-rolled sheet using gapless rolling technology includes: The hot rolling temperature is set at 1100-1300℃, the heating time is 30-60 minutes, the hot rolling equipment adopts a multi-pass hot rolling mill, the rolling speed is set at 1-5 m / min, the number of rolling passes is 4-6, and the plate thickness is checked after each pass; the cold rolling temperature is maintained at 25-300℃, and the rolling speed is set at 3-8 m / min to ensure efficient cold rolling.

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