Method for selecting a laser scribe substrate for oriented silicon steel
By establishing a magnetic domain-grain-iron loss relationship model, accurately screening substrates and setting laser marking process parameters, the problem of improper matching between substrate state and process parameters in laser marking technology is solved, resulting in a significant reduction in iron loss and an improvement in product performance. This model is suitable for efficient quality control of diverse raw materials.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ANGANG STEEL CO LTD
- Filing Date
- 2026-03-12
- Publication Date
- 2026-06-12
AI Technical Summary
The lack of scientific matching criteria between substrate condition and process parameters in existing laser marking technology leads to unstable marking effects, limited reduction in iron loss, and blind production and waste of resources.
A magnetic domain-grain-iron loss relationship model was established. By quantitatively describing the relationship between grain size, magnetic domain width and iron loss, the optimal magnetic domain width and the corresponding grain size range were calculated, and the substrate was accurately screened and the laser scribing process parameters were set.
It achieves a stable improvement in laser marking effect, significantly reduces iron loss, enhances product performance, reduces production costs, and provides a unified quality control tool applicable to grain-oriented silicon steel products of different specifications and performance levels.
Smart Images
Figure CN122193373A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of iron and steel metallurgy, and more particularly to a method for selecting a laser-etched substrate for oriented silicon steel. Background Technology
[0002] Grain-oriented silicon steel is a key soft magnetic material used in the manufacture of cores for electrical equipment such as power transformers and motors. Its magnetic properties directly affect the operating efficiency and energy consumption of the equipment. Iron loss is one of the core indicators for evaluating the performance of grain-oriented silicon steel, mainly including hysteresis loss, eddy current loss, and anomalous eddy current loss. Among these, anomalous eddy current loss is closely related to the magnetic domain structure of the material. After secondary recrystallization, grain-oriented silicon steel typically forms coarse grains, resulting in a larger magnetic domain width, which in turn significantly increases anomalous eddy current loss, limiting further reduction in iron loss performance.
[0003] To refine magnetic domains and reduce iron loss, various physical processing technologies have been developed in the industry. Among them, laser marking technology has become an important post-processing step in the production of high-performance grain-oriented silicon steel due to its advantages such as non-contact operation, high efficiency, significant effects, and good process stability. This technology introduces periodic thermal stress on the surface of the steel plate using a laser, inducing the formation of a regularly distributed narrow magnetic domain structure, thereby effectively reducing anomalous eddy current losses.
[0004] However, the final effect of laser scribing technology is not solely determined by process parameters (such as laser power, scanning speed, and scribing spacing), but is also significantly influenced by the initial state of the substrate. A complex coupling relationship exists between the initial microstructure of the substrate (such as the average grain size and grain uniformity after secondary recrystallization) and its initial magnetic properties (such as the iron loss value before scribing) and the achievable reduction in iron loss after scribing. Currently, there is considerable research in the industry on optimizing laser scribing process parameters, but a systematic guiding method and material selection criteria are lacking for scientifically selecting the most suitable base material for laser scribing based on the initial state of the substrate. Typically, there is a degree of blindness in production, relying heavily on experience or using fixed processes to treat substrates in different states. This results in some substrates failing to achieve optimal iron loss improvement, and even leading to a waste of resources and costs.
[0005] Therefore, developing a theoretically guided method for substrate selection that can correlate and match the initial state of the substrate (especially grain size and iron loss) with the optimal effect of laser marking is of great practical significance for achieving precision in the laser marking process of oriented silicon steel, maximizing product performance and reducing production costs. Summary of the Invention
[0006] The purpose of this invention is to provide a method for selecting substrates for laser marking of oriented silicon steel, in order to solve the problems of unstable marking effects and limited reduction in iron loss caused by the lack of scientific matching criteria between substrate condition and process parameters in existing laser marking technologies. By establishing a quantitative relationship model of "magnetic domain width-grain size-iron loss", the optimal magnetic domain width and corresponding grain size range are accurately calculated based on the initial microstructure and magnetic properties of the base material, thereby achieving precise selection of substrates and optimization of marking process settings, ultimately achieving a significant and stable improvement in the reduction of iron loss by laser marking and improving product performance.
[0007] To achieve the above objectives, the present invention provides the following technical solution: A method for selecting a laser-etched substrate for oriented silicon steel includes: S1. Establish a magnetic domain-grain-iron loss relationship model based on the relationship between grain size and magnetic domain width; S2. The magnetic properties of the secondary recrystallization structure of the grain-oriented silicon steel base material are tested to obtain the average grain size and initial iron loss value before the indentation. S3. Based on the established magnetic domain-grain-iron loss relationship model, and combined with the iron loss value of the base material, calculate the optimal magnetic domain width corresponding to the base material. ); S4. Based on the established magnetic domain-grain-iron loss relationship model, the optimal magnetic domain width ( Determine the optimal grain size range to match it; S5. Compare the average grain size obtained in step S2 with the optimal grain size range determined in step S4. If the average grain size falls within the optimal grain size range, then this grade of base material is selected for laser marking process.
[0008] In S1, the methods for establishing the magnetic domain-grain-iron loss relationship model include: S11. Based on the iron loss calculation formula of grain-oriented silicon steel, the optimal domain width that minimizes the total iron loss is determined by differentiation. )expression; S12, Establish the optimal domain width ( The relationship curve between the average grain size (D) and the average grain size (D); S13. Establish a comprehensive graph showing the relationship between domain width, average grain size and iron loss value.
[0009] In S11, the formula for calculating iron loss of grain-oriented silicon steel is: ①; in: Total iron loss, expressed in W / kg; Hysteresis loss, expressed in W / kg; Eddy current loss, expressed in W / kg; Domain wall energy, in J / m 2 ; The elastic constant is expressed in Pa. It is the magnetostriction coefficient; The grain size of the grain-oriented silicon steel is in mm. Resistivity, in Ω·m; Frequency, in Hz; The saturation magnetic flux density is expressed in tons (T). This represents the domain width, in mm. The thickness is in mm. Pi is the mathematical constant of a circle.
[0010] In S1, the optimal domain width ( The expression for ) is: ②; Based on the extreme value method, the optimal domain width at the stagnation point is... Total iron loss To obtain the minimum value; make The total iron loss was obtained. Optimal domain width to achieve minimum value .
[0011] In S4, the optimal grain size range is determined as follows: Based on the domain-grain-iron loss relationship model, the optimal domain width (determined by the iron loss value) Find the grain size that minimizes theoretical iron loss, and set the allowable deviation range centered on this grain size.
[0012] The allowable deviation range is ±0.5 mm of the optimal grain size.
[0013] It also includes: based on the selected base material and the optimal magnetic domain width corresponding to the base material ( ), set the process parameters for laser engraving, whereby the optimal magnetic domain width ( The optimal grain size determined by the method is used as the basis for selecting the base material.
[0014] Compared with the prior art, the beneficial effects of the present invention are: 1. For the first time, a comprehensive physical model capable of quantitatively describing the relationship between "grain size, magnetic domain width, and iron loss" was established. Based on this model, a complete set of substrate determination methods was formed. This allows for precise matching of the optimal magnetic domain width and corresponding optimal grain size range that theoretically minimizes iron loss, based on the initial microstructure (average grain size) and magnetic properties (initial iron loss) of the substrate before laser marking. This enables the scientific selection of the most suitable substrate for laser marking, overcoming the problems of blind material selection and unstable results caused by traditional methods that rely on process experience and ignore substrate condition matching. 2. The average grain size of the substrate selected by this invention is highly matched with the optimal grain size range calculated by the model, laying an ideal material foundation for the best effect of subsequent laser scribing; 3. The optimal domain width obtained from theoretical calculations ( This method of determining process parameters based on the physical nature of materials is more targeted than the traditional "trial and error" or fixed parameter method, and directly uses the core setting basis for key parameters of laser marking (such as marking spacing). It ensures that the stress field introduced by the laser can most effectively refine the magnetic domain structure, thereby stably achieving the expected goal of reducing iron loss. 4. The established model and method are based on the general physical principles of grain-oriented silicon steel. They are not only applicable to specific grades, but also provide universal material selection and process optimization guidance for laser marking processes of high magnetic induction grain-oriented silicon steel products with different specifications and performance levels. They provide production enterprises with unified and efficient quality control and process design tools when facing diverse raw materials, which helps to reduce production costs, reduce resource waste, and promote the standardized production of high magnetic induction grain-oriented silicon steel. 5. By closely integrating basic materials research (the relationship between magnetic domain theory and microstructure properties) with engineering applications (laser scribing technology), a closed-loop technical system of "theoretical prediction - experimental verification - process optimization" is formed, which helps to quickly screen and develop higher-performance scribing products. Attached Figure Description
[0015] Figure 1 It is a curve showing the relationship between domain width, average grain size and iron loss.
[0016] Figure 2 This is a graph showing the relationship between domain width, grain size, and iron loss in Example 1.
[0017] Figure 3 This is a graph showing the relationship between domain width, grain size and iron loss in Example 2.
[0018] Figure 4This is a graph showing the relationship between domain width, grain size and iron loss in Example 3.
[0019] Figure 5 This is a graph showing the relationship between domain width, grain size and iron loss in Example 4. Detailed Implementation
[0020] The present invention will now be described in detail with reference to the accompanying drawings, but it should be noted that the implementation of the present invention is not limited to the following embodiments.
[0021] The following embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiments. Unless otherwise specified, the methods used in the following embodiments are conventional methods.
[0022] Example: A method for selecting a laser-etched substrate for oriented silicon steel includes: S1. Establish a magnetic domain-grain-iron loss relationship model based on the relationship between grain size and magnetic domain width; Methods for establishing the magnetic domain-grain-iron loss relationship model include: S11. Based on the iron loss calculation formula of grain-oriented silicon steel, the expression for the optimal domain width (L0) that minimizes the total iron loss is determined by differentiation; The formula for calculating iron loss in grain-oriented silicon steel is: ①; in: Total iron loss, expressed in W / kg; Hysteresis loss, expressed in W / kg; Eddy current loss, expressed in W / kg; Domain wall energy, in J / m 2 ; The elastic constant is expressed in Pa. It is the magnetostriction coefficient; The grain size of the grain-oriented silicon steel is in mm. Resistivity, in Ω·m; Frequency, in Hz; The saturation magnetic flux density is expressed in tons (T). This represents the domain width, in mm. The thickness is in mm. Pi; In practical calculations, the relevant physical parameters can be set based on the properties of general high-magnetic-induction oriented silicon steel materials or determined experimentally. Taking a typical high-magnetic-induction oriented silicon steel (such as grade 23AG095) as an example, at a frequency... Domain wall energy under Hz conditions J / m², elastic constant Pa, magnetostriction coefficient resistivity Ω·m, saturation magnetic induction T, plate thickness mm.
[0023] S12, Establish the optimal domain width ( The relationship curve between P and average grain size (D) is derived and plotted based on the theoretical model of iron loss in oriented silicon steel and the intrinsic parameters of the material, which makes the total iron loss (P)... T When the minimum is reached, the optimal domain width is ( The quantitative correlation curve between the average grain size (D) and the average grain size (D) is shown in [the figure]. Figure 1 ).
[0024] S13. Establish a comprehensive graph showing the relationship between domain width, average grain size and iron loss value.
[0025] Based on theoretical formulas and a large amount of experimental data, it is possible to construct Figure 1 A two-dimensional relational graph visually displays the magnetic domain width ( ), average grain size ( ) and total iron loss ( The quantitative relationship between the three provides a theoretical basis for subsequent material selection.
[0026] Optimal domain width ( The expression for ) is: ②; Based on the extreme value method, the optimal domain width at the stagnation point is... Total iron loss Obtain the minimum value; make From this, we can deduce the above-mentioned total iron loss. Optimal domain width to achieve minimum value .
[0027] Taking the first case in Example 1 (iron loss of 0.82 W / kg before scoring) as an example, the relevant material parameters are substituted into Formula ② for calculation, and combined with... Figure 1 The relationship curve yields an optimal domain width of 0.153 mm. Based on the calculated domain width, a comparison is made... Figure 1 The domain width-grain size curve can be used to plot the relationship between domain width, grain size, and iron loss in Examples 1-4, see [reference]. Figure 2 Thus, the appropriate grain size corresponding to the magnetic domain width is selected, as shown in Table 1.
[0028] S2, Base Material Inspection; Four types of grain-oriented silicon steel finished sheets with properties as shown in Examples 1-4 of Table 1 were selected as candidate base materials. The initial iron loss value was measured using an Epstein square ring or single-piece tester under conditions of magnetic induction intensity of 1.7T and frequency of 50Hz. The initial iron loss in Example 1 was 0.82 W / kg.
[0029] S3. Based on the established magnetic domain-grain-iron loss relationship model, and combined with the iron loss value of the base material, calculate the optimal magnetic domain width corresponding to the base material. ); use Figure 1 The relationship model shown is based on the measured initial iron loss value of the parent material (P). T By searching on the model curve or by reverse-engineering the model formula, one or more theoretically optimal domain widths corresponding to this iron loss value can be obtained. For example, for the parent material of Example 1 with an initial iron loss of 0.82 W / kg, two corresponding optimal domain width values were obtained from the model, which are 0.153 mm and 0.200 mm, respectively. The specific data are shown in Table 1.
[0030] S4. Based on the established magnetic domain-grain-iron loss relationship model, the optimal magnetic domain width ( The optimal grain size range is determined based on the domain-grain-iron loss relationship model, within the optimal domain width determined by the iron loss value. Under the given conditions, find the grain size that minimizes the theoretical iron loss.
[0031] Based on the optimal domain width value calculated in step S3, query again... Figure 1 The model curves shown are used to find each... The ideal average grain size corresponding to the value that minimizes the theoretical value of iron loss. For example, for =0.153 mm, and the corresponding optimal matching grain size is 7.2 mm; for =0.200 mm, and the corresponding optimal matching grain size is 10.4 mm.
[0032] S5. Compare the optimal grain size ranges (7.2±0.5mm and 10.4±0.05mm) determined in step S4. The actual average grain size of the base material is 7.5 mm. If it is within the optimal grain size range, then this grade of base material will be laser-etched.
[0033] S6. Based on the selected base material and the optimal magnetic domain width corresponding to the base material ( ), set the laser engraving process parameters. After selecting these base materials, according to the corresponding optimal magnetic domain width ( Laser scoring was performed on four types of finished boards with similar performance. The performance after scoring is shown in Table 1, with iron loss reduction of more than 8.5%. The comparative examples in Table 1 are the performance of four types of finished boards with similar performance, selected with random substrates and laser scoring using conventional default scoring parameters. The iron loss reduction is between 2.9% and 4.7%.
[0034] As can be seen from the comparative examples and comparative examples, under the same iron loss conditions, after laser marking using the embodiments of the present invention, the reduction in iron loss can be increased by more than double, and the product can be upgraded by one grade.
[0035] Table 1 shows the parameters for the examples and comparative examples.
[0036] This invention establishes for the first time a comprehensive physical model that can quantitatively describe the relationship between "grain size, magnetic domain width, and iron loss," and based on this model, forms a complete substrate determination system. This allows for precise matching of the theoretically optimal magnetic domain width and corresponding optimal grain size range that minimizes iron loss before laser etching, based on the initial microstructure (average grain size) and magnetic properties (initial iron loss) of the substrate. This scientifically selects the most suitable substrate for laser etching, overcoming the problems of blind material selection and unstable results caused by traditional methods relying on process experience and neglecting substrate condition matching. The substrates selected by this invention have an average grain size that highly matches the optimal grain size range calculated by the model, laying an ideal material foundation for the subsequent optimal laser etching effect. The theoretically calculated optimal magnetic domain width ( This method, based on the fundamental physical properties of materials, directly serves as the core basis for setting key parameters of laser marking (such as marking spacing). It is more targeted than traditional trial-and-error or fixed-parameter methods, ensuring that the stress field introduced by the laser can most effectively refine the magnetic domain structure, thereby stably achieving the expected reduction in iron loss. The established model and method, based on the general physical principles of grain-oriented silicon steel, are not only applicable to specific grades but also provide universal material selection and process optimization guidance for laser marking processes of high-magnetic-induction grain-oriented silicon steel products of different specifications and performance levels. It provides manufacturers with unified and efficient quality control and process design tools when facing diverse raw materials, helping to reduce production costs, minimize resource waste, and promote the standardized production of high-magnetic-induction grain-oriented silicon steel. By closely integrating fundamental material research (the relationship between magnetic domain theory and microstructure properties) with engineering applications (laser marking process), a closed-loop technical system of "theoretical prediction - experimental verification - process optimization" is formed, facilitating the rapid screening and development of higher-performance marking products.
Claims
1. A method for selecting a laser-etched substrate for oriented silicon steel, characterized in that, include: S1. Establish a magnetic domain-grain-iron loss relationship model based on the relationship between grain size and magnetic domain width; S2. The magnetic properties of the secondary recrystallization structure of the grain-oriented silicon steel base material are tested to obtain the average grain size and initial iron loss value before the indentation. S3. Based on the established magnetic domain-grain-iron loss relationship model, and combined with the iron loss value of the base material, calculate the optimal magnetic domain width corresponding to the base material. ); S4. Based on the established magnetic domain-grain-iron loss relationship model, the optimal magnetic domain width ( Determine the optimal grain size range to match it; S5. Compare the average grain size obtained in step S2 with the optimal grain size range determined in step S4. If the average grain size falls within the optimal grain size range, then this grade of base material is selected for laser marking process.
2. The method for selecting a laser-etched substrate for oriented silicon steel according to claim 1, characterized in that, In S1, the method for establishing the magnetic domain-grain-iron loss relationship model includes: S11. Based on the iron loss calculation formula of grain-oriented silicon steel, the optimal domain width that minimizes the total iron loss is determined by differentiation. )expression; S12, Establish the optimal domain width ( The relationship curve between the average grain size (D) and the average grain size (D); S13. Establish a comprehensive graph showing the relationship between domain width, average grain size and iron loss value.
3. The method for selecting a laser-etched substrate for oriented silicon steel according to claim 2, characterized in that, In S11, the formula for calculating the iron loss of the oriented silicon steel is as follows: ①； in: Total iron loss, expressed in W / kg; Hysteresis loss, expressed in W / kg; Eddy current loss, expressed in W / kg; Domain wall energy, in J / m 2 ; The elastic constant is expressed in Pa. It is the magnetostriction coefficient; The grain size of the grain-oriented silicon steel is in mm. Resistivity, in Ω·m; Frequency, in Hz; The saturation magnetic flux density is expressed in tons (T). This represents the domain width, in mm. The thickness is in mm. Pi is the mathematical constant of a circle.
4. The method for selecting a laser-etched substrate for oriented silicon steel according to claim 2, characterized in that, In S1, the optimal magnetic domain width ( The expression for ) is: ②； Based on the extreme value method, the optimal domain width at the stagnation point is... Total iron loss To obtain the minimum value; make The total iron loss was obtained. Optimal domain width to achieve minimum value .
5. The method for selecting a laser-etched substrate for oriented silicon steel according to claim 1, characterized in that, In S4, the optimal grain size range is determined as follows: Based on the domain-grain-iron loss relationship model, the optimal domain width (determined by the iron loss value) Find the grain size that minimizes theoretical iron loss, and set the allowable deviation range centered on this grain size.
6. The method for selecting a laser-etched substrate for oriented silicon steel according to claim 5, characterized in that, The allowable deviation range is ±0.5 mm of the optimal grain size.
7. The method for selecting a laser-etched substrate for oriented silicon steel according to claim 1, characterized in that, Also includes: Based on the selected base material and the corresponding optimal magnetic domain width ( ), set the process parameters for laser engraving, whereby the optimal magnetic domain width ( The optimal grain size determined by the method is used as the basis for selecting the base material.