Coating for a grain-oriented silicon steel coating layer, as well as grain-oriented silicon steel sheet and method for manufacturing the same.

Abstract

A coating is provided, comprising a phosphate, colloidal silicon dioxide and a chromate compound, wherein the phosphate comprises magnesium dihydrogen phosphate and aluminum dihydrogen phosphate, and the molar ratio of Al to Mg in the phosphate is 0.02-0.15. A grain-oriented silicon steel sheet is provided, comprising a substrate and a coating layer on a surface of the substrate, wherein the coating layer is formed by the coating. A manufacturing method for grain-oriented silicon steel sheet is provided, the method comprising the steps of: covering a surface of a substrate with a coating, and then subjecting it to a sintering process, wherein the plate temperature during the sintering process is 800-880°C. The coating layer formed by the coating can provide grain-oriented silicon steel with higher tensile strength and better heat resistance, and has good promotion prospects and application effect.

Description

Technical Field

[0001] Technical Field The present disclosure relates to coatings, as well as steel sheets and methods for manufacturing the same, particularly coatings for a grain-oriented silicon steel coating layer, as well as grain-oriented silicon steel sheets and methods for manufacturing the same.

Background Art

[0002] Background Art As is well known in the art, a grain-oriented silicon steel sheet refers to an electromagnetic steel sheet in which the steel contains silicon and the direction of the easy magnetization axis of the particles (100)<001> substantially coincides with the rolling direction. Grain-oriented silicon steel sheets are mainly used for manufacturing transformer cores, which have excellent electromagnetic properties in the rolling direction and are important soft magnetic materials. When grain-oriented silicon steel sheets are used as materials for manufacturing transformer cores, the energy loss and noise level of the transformers can be effectively reduced.

[0003] Currently, imparting high tension to grain-oriented silicon steel by means of a surface coating layer is an important technical method for improving the performance of grain-oriented silicon steel. In the prior art, the surface coating layer of a grain-oriented silicon steel sheet generally consists of a forsterite (Mg2SiO4)-based ceramic film and an insulating coating layer thereon. The insulating coating layer can serve the functions of insulation, rust prevention, and improvement of workability.

[0004] Under normal circumstances, the surface coating layer of grain-oriented silicon steel is formed at a high temperature. When the temperature of a grain-oriented silicon steel sheet having a surface coating layer thereon drops to room temperature, since the surface coating layer has a lower coefficient of thermal expansion than the steel sheet, the difference in the coefficient of thermal expansion between the steel sheet and the coating layer applies tension to the steel sheet. The tension applied to the steel sheet can reduce the loss of grain-oriented silicon steel (the abnormal eddy current loss is reduced by narrowing the width of the 180° magnetic domain) and magnetostriction. Therefore, the energy loss and noise level of the transformer can be effectively reduced.

[0005] In recent years, many scientists and engineers have undertaken numerous beneficial experiments and designed many new surface coating layers to further improve the performance of grain-oriented silicon steel.

[0006] A Japanese patent document, publication number JPS4839338A and publication date June 9, 1973, titled "Method for forming an insulating coating on a grain-oriented silicon steel sheet," discloses a coating comprising aluminum dihydrogen phosphate, colloidal silica, and chromic anhydride. After applying the above coating to the surface of grain-oriented silicon steel and subjecting it to heat treatment, a glass coating layer based on MgO-P2O5-SiO2 and Al2O3-P2O5-SiO2 phosphates is formed on the surface of the steel sheet.

[0007] A Chinese patent document, publication number CN107923046A and publication date April 17, 2018, titled "Insulating Coating Treatment Solution and Method for Producing Metal Having an Insulating Coating," discloses an insulating coating treatment solution comprising at least one phosphate selected from the group consisting of Mg, Ca, Ba, Sr, Zn, Al, and Mn; and two or more colloidal silicas having different average particle sizes. In this application, the tension of the insulating coating layer is optimized and improved by colloidal silica having different particle sizes. In the above technical solution, the tightness of the coating layer can be improved to some extent by using a mixture of silica sols having different particle sizes, however, the room for improvement in tension is very limited.

[0008] A Chinese patent document, publication number CN104024474A and publication date September 3, 2014, titled "Grain-oriented electrical steel sheet having a coating layer and method for manufacturing the same," discloses a grain-oriented silicon steel sheet. In this application, a coating layer is prepared that contains the elements P, Si, Cr, and O, as well as at least one element selected from the group consisting of Mg, Al, Ni, Co, Mn, Zn, Fe, Ca, and Ba, and contains at least 5 wt% of a phosphoric acid crystalline phase, thereby achieving higher tensile stress and reduced iron loss. In the above technical solution, the tension imparted to the steel sheet by the insulating coating layer is improved by increasing the elastic modulus of the coating layer, which must be achieved by increasing the amount of chromic anhydride added and raising the temperature at which the coating layer is sintered. However, the range of the amount of chromic anhydride added to the phosphoric acid coating layer is very narrow. When the amount of chromic anhydride is increased to a certain extent, cracks and turbidity / turbidity occur in the coating layer. If the sintering temperature of the coating layer is higher than approximately 900°C, it causes crystallization of colloidal silica. The crystalline phase formed in the coating layer can increase tension, but this leads to a decrease in the corrosion resistance and transparency of the coating layer.

[0009] From the above, it can be seen that the performance imparted to grain-oriented silicon steel sheets by phosphoric acid-based glass coating layers in prior art is still not good, and still suffers from the drawbacks of insufficient tensile strength and low heat resistance. When transformer cores made of grain-oriented silicon steel sheets are subjected to stress relief annealing, the performance of the coating layer on the surface of the grain-oriented silicon steel deteriorates, leading to a decrease in tensile strength, and as a result, the energy loss and noise level of the transformer cannot be effectively reduced. [Overview of the project] [Means for solving the problem]

[0010] Summary of the Invention In light of the above technical challenges in this field, the inventors have creatively designed a new coating through extensive research. The coating can be applied to the surface of grain-oriented silicon steel to form a coating layer with improved tensile strength and heat resistance. The formed coating layer can effectively reduce the energy loss and noise level of transformers. The coating according to this disclosure has good prospects and application effects.

[0011] One of the objectives of this disclosure is to provide a coating that can be used to form a surface coating layer on grain-oriented silicon steel sheets. The surface coating layer can provide grain-oriented silicon steel sheets with higher tensile strength and better heat resistance.

[0012] To achieve the above objective, this disclosure provides a coating comprising: a phosphate, colloidal silica, and a chromate compound; wherein the phosphate comprises magnesium dihydrogen phosphate and aluminum dihydrogen phosphate, and the molar ratio of element Al to element Mg in the phosphate (Al / Mg) is 0.02 to 0.15.

[0013] Preferably, the coating according to the present disclosure has an active component comprising a phosphate, colloidal silica, and a chromate compound; wherein the phosphate includes magnesium dihydrogen phosphate and aluminum dihydrogen phosphate, and the molar ratio of element Al to element Mg in the phosphate is 0.02 to 0.15.

[0014] In one embodiment, water may be used as the solvent for the coating. In one embodiment, the coating comprises a soluble phosphate, colloidal silica, and a chromic acid compound. In one embodiment, the phosphate may form a mesh-like structure on the surface of the steel sheet after being subjected to sintering heat treatment. In one embodiment, the colloidal silica and phosphate may form a coating layer having a low coefficient of thermal expansion after being subjected to sintering heat treatment.

[0015] It should be noted that in the coatings according to this disclosure, the phosphates include magnesium dihydrogen phosphate and aluminum dihydrogen phosphate, which contain a certain amount of free phosphate ions. The phosphates readily absorb and dissolve in water, thereby destroying the integrity of the formed coating layer. Therefore, in the coatings according to this disclosure, it is necessary to further add chromic acid compounds so that a stable CrPO4 can be formed. The chromic acid compounds play a role in immobilizing phosphate ions and improving the water resistance of the coating layer.

[0016] Through thorough research, the inventors have found that by adjusting the ratio of magnesium dihydrogen phosphate to aluminum dihydrogen phosphate within a certain range, the tension of the coating layer formed after the coating is applied to the surface of grain-oriented silicon steel can be significantly improved, and the degree of tensile degradation of the coating layer after stress relief annealing can be reduced. Therefore, in order to ensure the quality of the coating layer, the molar ratio of element Al to element Mg in the phosphate is controlled to 0.02 to 0.15, preferably 0.02 to 0.085.

[0017] When the molar ratio of element Al to element Mg is lower than 0.02, the effect of improving the tension of the coating layer is not clear; when the molar ratio of Al to Mg is higher than 0.15, the effect of improving the tension of the coating layer is not clear, and it should be noted that the tension of the coating layer deteriorates after stress relief annealing. Therefore, in the coating according to this disclosure, the molar ratio of element Al to element Mg is controlled between 0.02 and 0.15.

[0018] Preferably, in the coating according to this disclosure, the mass ratio of colloidal silica to phosphate (colloidal silica / phosphate) is 0.8 to 1.2. By controlling the mass ratio of colloidal silica to phosphate between 0.8 and 1.2, the tensile effect of the coating layer on grain-oriented silicon steel can be more effectively exhibited.

[0019] In the technical solution of the present disclosure, the addition of a chromic acid compound can play a role in immobilizing phosphate ions and improving the water resistance of the coating layer. When the mass ratio of the chromic acid compound to the phosphate is 0.1 or more, the moisture resistance of the coating layer can be improved. When the mass ratio of the chromic acid compound to the phosphate is 0.5 or less, the turbidity / turbulence and cracking of the coating layer can be reduced, and moreover, the tension and corrosion resistance of the coating layer can be improved.

[0020] Therefore, in the coating according to the present disclosure, in order to achieve better moisture resistance, tension, and corrosion resistance of the coating layer, and to reduce the turbidity / turbulence and cracking of the coating layer, it is also preferable to further control the mass ratio of the chromic acid compound to the phosphate. In a preferred embodiment, the mass ratio of the chromic acid compound to the phosphate (chromic acid compound / phosphate) is 0.1 to 0.5, more preferably 0.2 to 0.4.

[0021] Another object of the present disclosure is to provide a grain-oriented silicon steel sheet coated with the coating according to the present disclosure, and as a result, the grain-oriented silicon steel sheet has excellent properties. The tension imparted to the grain-oriented silicon steel sheet by the coating layer formed from the coating according to the present disclosure can effectively reduce the loss and magnetostriction of the grain-oriented silicon steel. The grain-oriented silicon steel sheet according to the present disclosure can be used as a material for manufacturing the core of a transformer, which can effectively reduce the energy loss and noise level of the transformer.

[0022] To achieve the above object, the present disclosure provides a grain-oriented silicon steel sheet including a base material and a coating layer on the surface of the base material, wherein the coating layer is formed from the coating described in the present disclosure.

[0023] Preferably, the grain-oriented silicon steel sheet according to the present disclosure has a surface tension of >8 MPa and a tension deterioration degree before and after stress relief annealing treatment of ≦5%.

[0024] Preferably, the grain-oriented silicon steel sheet according to the present disclosure has an iron loss P of 0.6 to 1.37 W / kg after stress-relieving annealing treatment. 17 / 50 It has.

[0025] In the grain-oriented silicon steel sheet according to the present disclosure, in order to achieve better tension and insulation effects of the coating layer while increasing the stacking factor of the steel sheet, the coating layer can be controlled to have a one-sided dry film amount within a certain range. When the coating layer has a one-sided dry film amount of 2 g / m 2 or more, the tension and insulation effects of the coating layer can be improved. When the coating layer has a one-sided dry film amount of 8 g / m 2 or less, the stacking factor of the steel sheet can be improved. Therefore, in the grain-oriented silicon steel sheet according to the present disclosure, it is preferable that the coating layer has a one-sided dry film amount of 2 to 8 g / m 2 . In a further preferred embodiment, the coating layer has a one-sided dry film amount of 3 to 6 g / m 2 .

[0026] Preferably, the substrate has a thickness of 0.15 to 0.50 mm.

[0027] In the grain-oriented silicon steel sheet according to the present disclosure, the composition of the substrate in the grain-oriented silicon steel sheet is not particularly limited. Any prior art component system that can achieve the technical effects of the present disclosure can be used. Preferably, the substrate is a ferrosilicon alloy having a Goss texture, and the substrate has a Si element content of 2% to 4% by mass percentage.

[0028] Preferably, the substrate has a forsterite-free ceramic film or a forsterite-containing ceramic film on its surface.

[0029] A further object of the present disclosure is to provide a method for manufacturing the above-mentioned grain-oriented silicon steel sheet. The above-mentioned grain-oriented silicon steel sheet can be efficiently produced by this manufacturing method.

[0030] To achieve the above objective, the present disclosure provides a method for manufacturing a grain-oriented silicon steel sheet, comprising the steps of: applying a coating to the surface of a substrate; and subsequently performing a sintering treatment, wherein the substrate has a temperature of 800 to 880°C (i.e., substrate temperature), and the sintering treatment is performed at this temperature.

[0031] In the method for manufacturing grain-oriented silicon steel sheets according to this disclosure, the substrate temperature, at which the sintering treatment is performed, is controlled to be between 800°C and 880°C. This is because: if the substrate temperature during the sintering treatment is lower than 800°C, the objective of flatness of the steel sheet cannot be achieved, and the effect of the coating layer in providing tension to the steel sheet is not significant. If the substrate temperature during the sintering treatment is higher than 880°C, the silica in the coating layer tends to form crystalline silica, resulting in a decrease in the tightness and tension of the coating layer.

[0032] Compared to prior art, the coatings according to this disclosure, as well as grain-oriented silicon steel sheets and methods for manufacturing them, have the following advantages and beneficial effects:

[0033] In the coating according to this disclosure, the inventors designed and controlled the molar ratio of element Al and element Mg in the mixed phosphate of magnesium dihydrogen phosphate and aluminum dihydrogen phosphate. By controlling the two molar ratios between 0.02 and 0.15, it is ensured that the coating layer formed by applying the coating to the surface of grain-oriented silicon steel can provide the steel sheet with higher tensile strength and better heat resistance.

[0034] The grain-oriented silicon steel sheet coated with the above-described coating according to this disclosure has extremely excellent performance. The tension imparted to the steel sheet by the coating layer formed from the coating according to this disclosure can effectively reduce the losses and magnetostriction of the grain-oriented silicon steel. The grain-oriented silicon steel sheet according to this disclosure can be used as a material for manufacturing the core of a transformer, and can effectively reduce the energy loss and noise level of the transformer. [Brief explanation of the drawing]

[0035] [Figure 1] Figure 1 schematically shows the relationship between the molar ratio of element Al to element Mg in the phosphate in the coating and the tensile stress (coating layer tension) applied to the steel sheet by the coating layer. [Modes for carrying out the invention]

[0036] Detailed explanation All technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which this disclosure pertains, unless expressly indicated otherwise. It should be understood that the terms used in the description of this disclosure are for the purpose of describing specific embodiments only and not to limit them.

[0037] In this specification, tension may be determined by methods commonly used in the art, such as those described in the examples.

[0038] In this specification, the expression "degree of tension degradation before and after stress relief annealing treatment" refers to the percentage change in tension before and after stress relief annealing treatment, i.e., percentage change (%) = (tension value before stress relief annealing treatment - tension value after stress relief annealing treatment) / tension value before stress relief annealing treatment * 100%.

[0039] In this specification, the single-sided dry film amount refers to the mass per unit area of ​​the coating layer on one side surface of a steel sheet, which is determined by: removing the coating layer from the surface to be measured, and calculating based on the change in weight of the steel sheet and the area of ​​the steel sheet before and after the removal of the coating layer.

[0040] In this specification, iron loss P 17 / 50 This refers to the iron loss value measured under conditions of a magnetic flux density of 1.7 T and a frequency of 50 Hz.

[0041] In this specification, the coatings, as well as the grain-oriented silicon steel sheets and methods for producing them, are described and illustrated further with reference to the drawings and examples, but the description and illustration shall not constitute an unwarranted limitation to the technical solutions of this disclosure. All reagents used in the examples are available through commercial channels. Experimental methods for which specific conditions were not specified in the examples were carried out according to conventional conditions known in the art or conditions recommended by manufacturers.

[0042] Examples 1-15 and Comparative Examples 1-7 The coatings of Examples 1-15 and Comparative Examples 1-7 were prepared by mixing phosphates, colloidal silica, and chromic acid compounds. Table 1 lists the parts by mass and mass ratio of each component in the coatings of Examples 1-15 and Comparative Examples 1-7.

[0043] [Table 1]

[0044] It should be noted that in Examples 1-15 and Comparative Examples 1-7, all phosphates included Mg-containing dihydrogen phosphate and Al-containing dihydrogen phosphate. The molar ratio of element Al to element Mg in the phosphates of the Examples and Comparative Examples is shown in Table 2 below.

[0045] [Table 2]

[0046] It should be noted that in Examples 1-15 and Comparative Examples 1-7, all chromate compounds used in the examples and comparative examples were chromate anhydrides. Of course, in some other embodiments, chromates (such as magnesium dichromate, calcium chromate, and zinc chromate) can also be used as chromate compounds.

[0047] Next, the coatings from Examples 1-15 and Comparative Examples 1-7 were applied to a substrate of grain-oriented silicon steel sheet to prepare grain-oriented silicon steel sheets. Here, the substrate was a ferrosilicon alloy having a gothic structure.

[0048] The same base steel slab was used for the grain-oriented silicon steel sheets in the examples and comparative examples. Here, the mass percentages of each chemical element were as follows: C: 0.047%, Si: 3.23%, S: 0.008%, Als: 0.029%, N: 0.006%, Mn: 0.012%, and the remainder being Fe and other unavoidable impurities. Indeed, in some other embodiments, base steel slabs with other chemical compositions can also be used, and the base can be controlled to have an element Si content between 2% and 4% by mass percentage.

[0049] The grain-oriented silicon steel sheets in Examples 1-15 and Comparative Examples 1-7 were prepared by the following process: (1) Smelting and casting are carried out according to the mass percentage of the above chemical elements to obtain a base steel slab; (2) The steel slab is heated to a temperature of 1150°C, and then the slab is hot-rolled to obtain a hot-rolled plate with a thickness of 2.8 mm; (3) The hot-rolled sheet is pickled, and then cold-rolled to obtain a cold-rolled sheet having a thickness of 0.15 to 0.50 mm. Hereinafter, the cold rolling may be performed once, or two or more passes may be performed, and intermediate annealing may be performed in between; (4) The cold-rolled sheet is subjected to decarburization annealing, and then subjected to continuous nitriding in a wet protective atmosphere of nitrogen and hydrogen through which ammonia gas is passed; (5) A separator containing magnesium oxide as the main component is applied to the steel sheet after nitriding treatment; (6) After coil winding, secondary recrystallization annealing was performed in a dry protective atmosphere of nitrogen and hydrogen, where the annealing was controlled to a temperature of 1200°C and held at that temperature for 25 hours, thereby obtaining a substrate having a forsterite ceramic film coating and a gothic structure, the substrate having a thickness of 0.15 to 0.50 mm; (7) Apply a coating to the surface of the substrate; (8) Sinter at a temperature of 800~880 °C for 10 seconds or more to obtain a oriented silicon steel sheet, and a coating layer of 2~8 g / m² 2 The amount of dry film on one side is controlled to be such that it has a certain amount of film.

[0050] It should be noted that the coating according to this disclosure can be effectively applied regardless of whether the substrate has a forsterite ceramic film on its surface. Therefore, in the above manufacturing method, it is also possible to prevent the formation of a forsterite ceramic film on the surface of the steel sheet by controlling the decarburization annealing and the separator. The substrate may have a forsterite-free ceramic film or a forsterite-containing ceramic film on its surface.

[0051] Table 3 lists the relevant process parameters in the manufacturing methods for grain-oriented silicon steel sheets in Examples 1-15 and Comparative Examples 1-7.

[0052] [Table 3]

[0053] Next, the tension imparted to the grain-oriented silicon steel sheet with the obtained coating layer was determined. The performance of the coating layer was evaluated by measuring the rate of change in the coating layer tension before and after stress relief annealing. The method for measuring the coating layer tension is as follows. The test results are shown in Table 4.

[0054] (1) Tension σ of the single-sided coating layer: With the rolling direction as the length direction, a grain-oriented silicon steel sheet was cut into a sample sheet having a length of 300 mm and a width of 30 mm, and then the single-sided coating layer was removed. The amount of deflection of the sample sheet was measured, and the tension σ of the single-sided coating layer was calculated using the following formula.

[0055]

number

[0056] In the above formula, σ represents the tension of the coating layer, and its unit may be MPa; E represents the Young's modulus of the steel sheet, and its unit may be GPa; t represents the thickness of the steel sheet, and its unit may be mm; H represents the amount of warping, and its unit may be mm; and L represents the length of the steel sheet, and its unit may be mm.

[0057] This allows us to obtain the tension σ of the single-sided coating layer of the grain-oriented silicon steel sheets in Examples 1-15 and Comparative Examples 1-7, where the tension σ is the tension σ of the coating layer before stress relief annealing (SPA) treatment.

[0058] (2) A grain-oriented silicon steel sheet was subjected to stress relief annealing, and then the tension of the coating layer on the grain-oriented silicon steel sheet after stress relief annealing was tested. The process conditions for the stress relief annealing treatment were as follows: stress relief annealing heat treatment was performed at 800°C for 2 hours, and the atmosphere was 100% N2. The test method for the tension of the coating layer on the grain-oriented silicon steel sheet after SRA treatment was the same as the test method for the tension σ of the single-sided coating layer described above.

[0059] The heat resistance of grain-oriented silicon steel sheets in the examples and comparative examples was obtained by comparing the tensile strength values ​​of the coating layer of the grain-oriented silicon steel sheets before and after SRA treatment. A larger change in the tensile strength value of the coating layer before and after SRA heat treatment indicates worse heat resistance of the steel sheet; in contrast, a smaller change in the tensile strength value of the coating layer before and after SRA heat treatment indicates better heat resistance of the steel sheet.

[0060] (3) Iron loss: Iron loss P of grain-oriented silicon steel sheets in the examples and comparative examples after stress relief annealing (SRA) treatment at a magnetic flux density of 1.7 T and a frequency of 50 Hz. 17 / 50 We measured it.

[0061] Table 4 shows the relevant performance test results for grain-oriented silicon steel sheets in Examples 1-15 and Comparative Examples 1-7.

[0062] [Table 4]

[0063] Table 3 shows that in Examples 1 to 15, which used coatings satisfying the design control requirements of this disclosure, the performance of the resulting grain-oriented silicon steel sheets was excellent: iron loss was low; the surface coating layer tension σ before SRA was 8.56 to 14.56 MPa; and after stress relief annealing at high temperature, the coating layer tension σ did not deteriorate, i.e., the degree of deterioration was small (≤5%). From the above, it can be seen that the grain-oriented silicon steel sheets in Examples 1 to 15 showed excellent heat resistance.

[0064] However, in Comparative Examples 1 to 7, the coatings had parameters that did not satisfy the design control requirements of the present disclosure, and the molar ratio of element Al to element Mg did not satisfy the design requirements of the present disclosure, so the properties of the surface coating layer of the resulting grain-oriented silicon steel sheets were inferior: the coating layer tension was low and the heat resistance was poor. After subjecting the grain-oriented silicon steel sheets in Comparative Examples 1 to 7 to stress relief annealing (SRA) at high temperatures, the coating layer tension deteriorated significantly, and the degree of deterioration was much higher than that of the grain-oriented silicon steel sheets in Examples 1 to 15.

[0065] Figure 1 schematically shows the relationship between the molar ratio of element Al to element Mg in the phosphate in the coating and the tensile stress (coating layer tension) applied to the steel sheet by the coating layer.

[0066] As shown in Figure 1, a coating layer in which the molar ratio of element Al to element Mg in the phosphate is controlled between 0.02 and 0.15 exhibits higher tensile strength and superior heat resistance.

[0067] It should be noted that the combinations of technical features described in this disclosure are not limited to those described in the claims or in the specific embodiments. All technical features described in this disclosure can be combined or integrated in any way, provided that they do not conflict with each other.

[0068] It should also be noted that the embodiments described above are merely specific embodiments of the present disclosure. The present invention is not limited to the embodiments described above, and it is clear that all similar variations and modifications that can be directly obtained or readily conceived by those skilled in the art from the content disclosed herein are included within the scope of this disclosure.

Claims

1. It consists of phosphates, colloidal silica, and chromate compounds; The phosphate comprises magnesium dihydrogen phosphate and aluminum dihydrogen phosphate, and the molar ratio of element Al to element Mg in the phosphate is 0.02 to 0.15; The mass ratio of the colloidal silica to the phosphate is 0.8 to 1.2; and A coating in which the mass ratio of the chromate compound to the phosphate is 0.1 to 0.

5.

2. Substrate; and Coating layer on the surface of the substrate A grain-oriented silicon steel sheet comprising, wherein the coating layer is formed from the coating described in claim 1.

3. The grain-oriented silicon steel sheet according to claim 2, having a surface tension of >8 MPa and a tension degradation of ≤5% before and after stress relief annealing treatment.

4. A grain-oriented silicon steel sheet with an iron loss P of 0.6 to 1.37 W / kg after stress relief annealing treatment. 17 / 50 A grain-oriented silicon steel sheet according to claim 2, having the characteristics of the aforementioned material.

5. The coating layer is 2-8 g / m² 2 The orientation silicon steel sheet according to claim 2, having a dry film amount on one side.

6. The grain-oriented silicon steel sheet according to claim 2, wherein the base material has a thickness of 0.15 to 0.50 mm.

7. The grain-oriented silicon steel sheet according to claim 2, wherein the base material is a ferrosilicon alloy having a Goss texture, and the base material has a mass percentage content of 2% to 4% of element Si.

8. The grain-oriented silicon steel sheet according to claim 2, wherein the substrate has a forsterite-free ceramic film or a forsterite-containing ceramic film on its surface.

9. A method for producing a grain-oriented silicon steel sheet according to claim 2, comprising the steps of: applying a coating to the surface of a substrate; and subsequently performing a sintering treatment, wherein the substrate has a temperature of 800 to 880°C and the sintering treatment is performed at this temperature.

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