KR20130076644A - Oriented electrical steel sheets and method for manufacturing the same - Google Patents

Abstract

PURPOSE: An oriented electrical steel sheet and a manufacturing method thereof are provided to improve an adhesion of an insulation film by forming a nitride layer in which nitrogen is a main agent on a surface of a steel sheet. CONSTITUTION: An oriented electrical steel sheet and a manufacturing method thereof provide an oriented electrical steel sheet in which a forsterrite film is removed or a generation of the forsterrite film is suppressed. A nitride layer in which nitrogen is a main agent on a surface of the electrical steel is formed. An insulating film for granting a tension is formed on the nitride layer. The insulating film comprises an aluminium hydroxide nanofiber, and a metal phosphate. [Reference numerals] (S10) Step of providing a oriented electrical steel sheet in which a forsterite film is removed or a formation of the forsterite film is suppressed; (S20) Step of forming a nitride layer in which nitrogen is a main agent on a surface of the electrical steel; (S30) Step of forming an insulating film for granting a tension on the nitride layer

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a directional electric steel sheet,

The present invention relates to a grain-oriented electrical steel sheet, and more particularly to a grain-oriented electrical steel sheet formed with a nitride layer mainly composed of nitrogen on the surface of the steel sheet and an insulating film for applying tension on the nitride layer.

Directional electrical steel sheets have excellent magnetic properties in the rolling direction and are used as iron core materials for transformers, motors, generators and other electronic devices.

In particular, as a core material for a transformer, a material having low iron loss is required to reduce energy loss. Since it is effective to apply tension to the steel sheet in order to manufacture the steel sheet with low iron loss, methods for applying tension to the steel sheet and reducing iron loss by forming a film made of a material having a lower coefficient of thermal expansion than the steel sheet at high temperature have been tried. have.

In the conventional case, a technique of applying an insulating coating on a forsterite-based base coating, Japanese Patent Laid-Open No. 11-71683 discloses a method of improving the film tension by using colloidal silica having a high glass transition temperature and Japanese Patent Japanese Patent No. 3098691 and Japanese Patent No. 26881147 propose a technique of forming a high tensile oxide film on an electrical steel sheet by using alumina sol and a mixture of boric acid. In addition, Korean Patent Nos. 10-2010-0019226, 10-2011-0010483, and 10-2011-0015167 form a more powerful film tension effect by forming a coating composed mainly of colloidal silica and hematite sol or nickel. An environmentally friendly coating technology has been proposed.

The prior art is a method of imparting a tension on the forsterite-based coating, there is a problem that the iron loss improvement effect is insufficient to produce a high-grade electrical steel sheet of about 3 to 4% level.

In recent years, a mirror-oriented electrical steel sheet has been proposed in which a grain-oriented electrical steel sheet forsterite film is removed by means of pickling or the like or intentionally prevented from being produced. The mirror-oriented electrical steel sheet has the advantage of lowering the hysteresis loss by smoothly moving the magnetic domain by removing the pinning site on the surface that hinders the magnetic movement.

However, the oriented electrical steel sheet from which the forsterite coating has been removed has a beautiful surface and low roughness, and thus it is difficult to obtain sufficient adhesiveness with the conventional coating agent composed of colloidal silica and phosphate, and there is a slight improvement in iron loss due to the film tension. .

In order to solve the above problems, after the oriented electrical steel sheet high temperature annealing process, as a method of forming an amorphous silica oxide film on the surface of the steel sheet, Korean Patent No. 10-2004-0000301, Japanese Patent Laid-Open No. 7-278833, Japanese Patent Laid-Open No. 8 -191010 has been proposed to improve the film adhesion, but it is pointed out that the amorphous silica of irregular thickness formed between the base iron and the tension coating, rather the magnetic properties are impeded by the interference of the magnetic domain movement.

In addition, Japanese Patent 2001-279460 proposes a method of adding an organometallic compound having an organic bonding group to the surface of a grain-oriented electrical steel sheet which suppresses the formation of the forsterite coating. It is pointed out that a problem of causing color deviation defects and film peeling occurs.

The present invention has been made to solve the above problems, and after forming a nitride layer mainly composed of nitrogen on the surface of the steel plate without a forsterite coating, the surface of the steel sheet is coated with a mixture of aluminum hydroxide nanofibers and metal phosphate The present invention relates to a grain-oriented electrical steel sheet coated with and formed with an insulating coating and a method of manufacturing the same.

In order to achieve the above object, the grain-oriented electrical steel sheet according to one embodiment of the present invention is a grain-oriented electrical steel sheet in which a forsterite (Mg ₂ SiO ₄ ) film is removed or its production is suppressed, and mainly nitrogen is formed on the surface of the steel sheet. The nitride layer is formed, characterized in that the insulating film for imparting tension on the nitride layer is formed.

The average thickness of the nitride layer may be 2nm ~ 500nm.

The insulating film may be made of aluminum hydroxide nanofibers and metal phosphate.

The metal phosphate may be a phosphate of at least one metal selected from the group consisting of alumina, magnesium, manganese and zinc.

The directional electrical steel sheet, % By weight Si: 1.0-7.0%, Sn: 0.01-0.6%, acid-soluble Al: 0.02-0.04%, Mn: 0.01-0.30%, C: 0.02-0.10%, S: 0.001-0.01%, balance Fe And other unavoidable impurities.

Method for producing a grain-oriented electrical steel sheet according to an embodiment of the present invention is to provide a grain-oriented electrical steel sheet is a forsterite (Mg ₂ SiO ₄ ) film is removed or the production is suppressed, nitrogen on the surface of the electrical steel sheet Forming a nitride layer mainly consisting of, and forming an insulating film for imparting a tension on the nitride layer.

The average thickness of the nitride layer may be 2nm ~ 500nm.

The nitride layer is formed by annealing the electrical steel sheet in an atmosphere containing hydrogen, nitrogen, ammonia, and water, maintaining an oxidation capacity (P _{H 2 O} / P _{H 2} ) at 0.001 to 0.03, and a temperature range of 650 ° C. to 1,100. Can be.

The insulating film may be made of aluminum hydroxide nanofibers and metal phosphate.

The metal phosphate may be a phosphate of at least one metal selected from the group consisting of alumina, magnesium, manganese and zinc.

The insulating film may be formed by applying a coating material consisting of the aluminum hydroxide nanofibers and the metal phosphate onto the nitride layer, and then heat-treating in a gas atmosphere in which hydrogen and nitrogen are mixed.

The heat treatment may be performed for 5 seconds to 10 minutes at a temperature of 700 ℃ or more.

After the heat treatment, the dried insulating coating amount may be 0.1 ~ 6.0g / m ² .

Film adhesion of the electrical steel sheet may be less than 40mmΦ.

In addition, the grain-oriented electrical steel sheet, % By weight Si: 1.0-7.0%, Sn: 0.01-0.6%, acid-soluble Al: 0.02-0.04%, Mn: 0.01-0.30%, C: 0.02-0.10%, S: 0.001-0.01%, balance Fe And other unavoidable impurities.

According to the present invention, by forming a nitride layer mainly composed of nitrogen on the surface of the steel sheet of the grain-oriented electrical steel sheet can be produced a grain-oriented electrical steel sheet with improved adhesion of the insulating film.

In addition, the grain-oriented electrical steel sheet according to the present invention has excellent iron loss characteristics, high film tension, and excellent magnetic properties.

1 is a process chart of a grain-oriented electrical steel sheet according to an embodiment of the present invention.
2 is an HR-TEM photograph of aluminum hydroxide nanofibers as a component of a coating agent for forming an insulating coating on a grain-oriented electrical steel sheet according to the present invention.
3 is a view showing the XRD analysis of the aluminum hydroxide nanofibers of FIG.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, it is to be understood that the present invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. It is intended that the disclosure of the present invention be limited only by the terms of the appended claims. Like reference numerals refer to like elements throughout the specification.

Hereinafter, a directional electric steel sheet according to a preferred embodiment of the present invention will be described.

The grain-oriented electrical steel sheet according to a preferred embodiment of the present invention is a grain-oriented electrical steel sheet in which a forsterite (Mg ₂ SiO ₄ ) film is removed or its production is suppressed, and a nitride layer mainly composed of nitrogen is formed on the surface of the steel sheet. The insulating film for imparting tension on the nitride layer is formed.

The average thickness of the nitride layer is characterized in that 2nm ~ 500nm.

The insulating film is made of aluminum hydroxide nanofibers and metal phosphate.

In addition, the metal phosphate is characterized in that the phosphate of at least one metal selected from the group consisting of alumina, magnesium, manganese and zinc.

1 is a manufacturing process diagram of a grain-oriented electrical steel sheet according to the present invention.

Method of manufacturing a grain-oriented electrical steel sheet according to another embodiment of the present invention is to provide a grain-oriented electrical steel sheet (Forsterite, Mg ₂ SiO ₄ ) film is removed or its production is suppressed (S10), of the electrical steel sheet Forming a nitride layer mainly composed of nitrogen on the surface (S20), and forming an insulating film for applying tension on the nitride layer (S30).

A grain-oriented electrical steel sheet exhibits a GOSS texture having a texture of {110} <001> with respect to the rolling direction, and is a soft magnetic material having excellent magnetic properties in one direction or in the rolling direction.

Forsterite coating is the main component of the coating agent in the process of decarburizing and nitriding annealing during the manufacturing process of the grain-oriented electrical steel sheet, and then applying the annealing separator to prevent sticking between materials during high temperature annealing to form secondary recrystallization. Magnesium oxide (MgO) is formed by reacting with silicon contained in the steel. These forsterite serves to inhibit the movement of the magnetic domain of the electrical steel sheet.

A grain-oriented electrical steel sheet without a forsterite (Mg ₂ SiO ₄ ) film may reduce magnetic hysteresis loss by smoothly moving magnetic steel sheets.

The grain-oriented electrical steel sheet without the forsterite coating may be formed by removing a forsterite coating formed on the surface of the electrical steel sheet by means of pickling or the like, or by applying an annealing separator to the surface of the steel sheet during high temperature annealing of the steel sheet. The use of alumina (Al ₂ O ₃ ) instead of MgO) can intentionally prevent its production.

On the other hand, the oriented electrical steel sheet from which the forsterite coating has been removed has a beautiful surface and low roughness, so that it is difficult to obtain sufficient adhesion with the conventional coating material composed of colloidal silica and phosphate, and the iron loss improvement effect due to the film tension may be insignificant.

A nitride layer mainly composed of nitrogen is formed on the surface of the steel sheet so that the insulating film can be adhered to the surface of the steel plate free of forsterite.

The nitride layer is formed by annealing the electrical steel sheet in an atmosphere containing hydrogen, nitrogen, ammonia, and water, while maintaining an oxidation capacity (P _{H 2 O} / P _{H 2} ) at 0.001 to 0.03, at a temperature range of 650 ° C to 1,100 ° C. Can be done.

In the annealing process, decarburization of the steel sheet occurs, and water and carbon in the steel sheet react to decarburize carbon monoxide and carbon dioxide. Hydrogen gas serves to regulate the rate of this reaction.

In order to form the nitride layer, the oxidation capacity (P _{H 2 O} / P _{H 2} ) is maintained at 0.001 or more and 0.03 or less, and it is important to control the annealing temperature to 650 ° C. or more and less than 1100 ° C.

Oxidation capacity is defined as water vapor partial pressure / hydrogen partial pressure in the atmosphere, and is also related to decarburization. In oriented electrical steel sheets, in order to reduce the carbon content of the product below a certain content, steam is blown into the atmosphere to perform decarburization.

If the oxidation potential is less than 0.001, it is difficult to form a nitride layer having an appropriate thickness. If the oxidation potential is 0.03 or more, internal diffusion of oxygen is generated, resulting in a thick SiO 2 oxide layer, and inferior iron loss.

In addition, when the annealing temperature is less than 650 ℃, there is a problem that the productivity of the nitride layer is slow, the productivity is low, and when the annealing temperature is 1,100 ℃ or more there is a problem that the nitride layer is formed thick and the magnetic inferior.

The average thickness of the nitride layer of the prepared grain-oriented electrical steel sheet is characterized in that 2nm ~ 500nm.

When the thickness of the nitride layer is less than 2 nm, adhesion between the coating material and the interface composed of aluminum hydroxide and metal phosphate constituting the insulating film used in the present invention may not be sufficient, and the insulating film may be peeled off during heat treatment.

On the other hand, when the thickness of the nitride layer is greater than 500nm, the adhesion between the coating material and the base iron interface is excellent, but when the heat treatment at a high temperature, the nitrogen compound diffuses into the material may lower the magnetic properties.

The insulating film is made of aluminum hydroxide nanofibers and metal phosphate.

The metal phosphate is characterized in that the phosphate of at least one metal selected from the group consisting of alumina, magnesium, manganese and zinc.

In addition, the insulating film is formed by applying a coating material consisting of the aluminum hydroxide nanofibers and the metal phosphate on the nitride layer, followed by heat treatment in a gas atmosphere mixed with hydrogen and nitrogen.

The heat treatment is characterized in that for 5sec ~ 10 minutes at a temperature of 700 ℃ or more.

After forming a nitride layer on the surface of the steel plate without the forsterite coating, a coating agent composed of aluminum hydroxide nanofibers and metal phosphate may be coated on the surface of the steel sheet, followed by high temperature heat treatment at 700 ° C. or higher to form a dense ceramic film.

The aluminum hydroxide nanofiber is composed of a hydroxyl group on the surface is easy to disperse in water, forms a strong hydrogen bond with the metal phosphate and the nitride layer on the surface of the steel sheet has excellent adhesion.

In addition, a high temperature heat treatment at 700 ° C. or higher forms a dense ceramic film, thereby improving insulation characteristics and corrosion resistance. However, when the heat treatment is performed at a temperature below 700 ° C., pores collapse within the coating film, thereby forming a porous film. Corrosion resistance is poor and film peeling may occur.

After the heat treatment, the dried insulating film coating amount is characterized in that 0.1 ~ 6.0g / m2.

Film adhesion of the electrical steel sheet is characterized in that less than 40mmΦ. The smaller the film adhesiveness value is, the better.

Hereinafter, a method for producing a grain-oriented electrical steel sheet according to the present invention will be described in detail with reference to examples. The following examples are illustrative of the present invention only and are not intended to limit the scope of the present invention.

&Lt; Example 1 >

In the grain-oriented electrical steel sheet, a 0.23mm thick grain-oriented electrical steel sheet (300X60mm) manufactured by removing the forsterite coating by means of pickling or the like was used as a test material. After forming a nitride layer on the surface of the grain-oriented electrical steel sheet, a coating agent consisting of aluminum hydroxide nanofibers and phosphates was applied to evaluate the surface and magnetic properties in the following manner.

In the embodiment of the present invention, the component content of the grain-oriented electrical steel sheet used is, by weight% Si: 1.0-7.0%, Sn: 0.01-0.6%, acid-soluble Al: 0.02-0.04%, Mn: 0.01-0.30%, C: 0.02% to 0.10%, S: 0.001% to 0.01%, the balance is composed of Fe and other unavoidable impurities (a small amount of impurities contained in steel in the steelmaking and steelmaking processes).

SRA was annealed at 750 ℃ for 2 hours in a dry 100% N ₂ gas atmosphere. Insulation was expressed as the received current value when a current of 0.5V, 1.0A was passed under 300PSI pressure. Is shown as the minimum arc diameter without film peeling when bent 180 ° in contact with an arc of 10, 20, 30 ~ 100 mmφ, and the film appearance is evaluated by observing streaks, luster, etc.

Corrosion resistance is assessed for 5 hours at 35 ° C and NaCl solution for 8 hours. In this test, it is excellent when the area of rust generation is 5% or less, good when 20% or less, 20 ~ 50% slightly poor, 50 Above%, it was marked as bad.

The film tension was evaluated by applying a coating agent to one surface of the material and measuring the degree of warpage (H ㅄ) due to tensile stress.

The grain-oriented electrical steel slab was heated at a temperature of 1,150 ° C. for 210 minutes, and then hot rolled to prepare a 2.3 mm thick hot rolled steel sheet. Thereafter, the hot rolled steel sheet was heated to 1,120 ° C., held at 920 ° C. for 90 seconds, quenched in water, pickled, and cold rolled to a thickness of 0.23 mm, subjected to decarbonization and high temperature annealing, and then pickled with a forsterite coating. Removed.

Subsequently, in a mixed atmosphere consisting of hydrogen, nitrogen, ammonia, and water (dew point temperature), a nitride layer was formed on the surface of the steel sheet, and a coating material mixed with aluminum hydroxide and metal phosphate was applied to the surface of the steel sheet.

On the other hand, the coating amount of the coating agent was adjusted to 4.0 g / m ² for the evaluation of the coating properties, and was treated for 120 seconds in a drying furnace set to 850 ℃.

Table 1 below is a comparison of the measured surface and magnetic properties according to the test conditions. When the nitride layer was formed at the base iron interface under mixed atmosphere conditions, the adhesion was significantly improved.

In addition, it was found that the magnetic properties were the best when the nitride layer was formed to a thickness of 25 ~ 120 nm.

division Oxidation Nitride layer thickness (nm) Surface quality ^{1 )} Adhesiveness (mmΦ) Magnetic property W17 / 50 ²⁾ B8 ³⁾ Comparative example - - X 100 1.04 1.86 Example 1 0.001 2 △ 35 0.76 1.90 Example 2 0.01 25 ◎ 22 0.70 1.91 Example 3 0.02 70 ◎ 20 0.64 1.92 Example 4 0.03 120 ○ 20 0.67 1.92 Example 5 0.07 680 △ 50 0.84 1.89

Note) 1) Property determination (surface quality) / Excellent: ◎, Good: ○, Normal: △, Slightly poor: ▽, Poor: X

2) The iron loss (W _17/50), A indicates the rolling direction and the average loss (W / kg) in the rolling direction in the vertical direction when the magnetic flux density in 1.7Tesla at 50Hz frequency organic.

3) Magnetic flux density (B ₈ ) means the magnitude of magnetic flux density (Tesla) induced when a magnetic field of 800 A / m is added.

Table 2 shows the surface quality, adhesion, insulation and corrosion resistance of the dry film after forming a nitride layer having a thickness of 25 nm on the surface of the ferrous iron, and then applying a mixture of aluminum hydroxide nanofibers and metal phosphate 6: 4. to be. Each measurement is the average of 10 specimens. In addition, a comparative example is an evaluation result when using a mixture of magnesium phosphate (Mg (H ₂ PO ₄ ) ₂ ) and mono aluminum phosphate (Al (H ₂ PO ₄ ) ₃ ) alone.

division Metal phosphate Surface quality Adhesiveness
(mmΦ) Insulation
(mA) Corrosion resistance Comparative example - △ 70 790 X Example 1 Al ◎ 32 157 ○ Example 2 Mg ○ 34 577 △ Example 3 Mn ▽ 42 570 △ Example 4 Zn ▽ 51 450 ▽ Example 5 Al: Mg = 1: 1 ◎ 22 57 ◎ Example 6 Al: Mg: Zn = 1: 1: 1 ○ 27 120 ◎

From these results, it was confirmed that in the combination ratio of the metal phosphate introduced in the present invention, when aluminum and magnesium-based phosphate were mixed in a 1: 1 ratio, the iron loss was improved by coating adhesion, corrosion resistance, insulation, and tension imparting ability.

<Example 2>

After forming a nitride layer having a thickness of 70 nm on the base iron surface, aluminum hydroxide nanofibers and metal phosphate were mixed and applied at 6: 4, and the drying temperature was changed to 100 to 1100 ° C. to evaluate the film adhesion. It was dried for 120 seconds (sec) in a gas atmosphere in which hydrogen and nitrogen were mixed at 5:95. When the drying temperature is less than 700 ° C, there is a problem of poor corrosion resistance and peeling of the film due to the collapse of voids in the coating film to form a porous film. It was found to contribute to corrosion resistance.

<Example 3>

In the present invention, the aluminum hydroxide nanofibers were used by hydrothermal synthesis in the following manner. Aluminum tri-sec-butoxide (100 g) and butanol (30 mL) were placed in a reaction vessel equipped with a cooler, and heated at 120 ° C. for 2 hours. Subsequently, water (20 mL) was added to the reaction vessel, followed by continuous heating at the same temperature for 3 hours.

The reaction temperature was lowered to room temperature, the resulting solid was washed with acetone, and the obtained solid was dried for 24 hours to obtain aluminum hydroxide nanofibers (30 g). As shown in FIG. 2, the shape of the nanofiber structure was confirmed through HR-TEM analysis.

In addition, as shown in Figure 3, it was confirmed through the XRD analysis that the aluminum hydroxide structure.

In the grain-oriented electrical steel sheet according to the present invention, a forsterite coating film is removed by means of pickling or the like, or a tension imparting insulating film is formed on the electrical steel sheet produced by preventing the formation thereof.

In addition, by forming a nitride layer mainly composed of nitrogen having an average of 2 nm or more and 500 nm or less at the interface between the tension-imparting insulating film and the steel sheet, the film heat resistance and magnetic properties can be improved.

The oriented electrical steel sheet without forsterite coating is manufactured by controlling the atmosphere gas and the annealing temperature, adding ammonia gas to form a nitride layer on the surface, and then applying a coating agent composed of aluminum hydroxide nanofiber and metal phosphate salt. Thus, a grain-oriented electrical steel sheet excellent in magnetic properties can be provided.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, You will understand.

It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is shown by the following claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. .

Claims (15)

In the grain-oriented electrical steel sheet in which Forsterite (Mg ₂ SiO ₄ ) film is removed or its formation is suppressed,
A nitride layer mainly composed of nitrogen is formed on the surface of the steel sheet,
The grain-oriented electrical steel sheet, characterized in that the insulating film for imparting tension on the nitride layer is formed. The method of claim 1,
The average thickness of the nitride layer is a grain-oriented electrical steel sheet, characterized in that 2nm ~ 500nm. 3. The method according to claim 1 or 2,
The insulating film is a grain-oriented electrical steel sheet, characterized in that consisting of aluminum hydroxide nanofibers and metal phosphate. The method of claim 3, wherein
The metal phosphate is a grain-oriented electrical steel sheet, characterized in that the phosphate of at least one metal selected from the group consisting of alumina, magnesium, manganese and zinc. The method of claim 1,
The directional electrical steel sheet, % By weight Si: 1.0-7.0%, Sn: 0.01-0.6%, acid-soluble Al: 0.02-0.04%, Mn: 0.01-0.30%, C: 0.02-0.10%, S: 0.001-0.01%, balance Fe And oriented electrical steel sheets containing other unavoidable impurities. Providing a grain-oriented electrical steel sheet in which a forsterite (Mg ₂ SiO ₄ ) film is removed or its production is suppressed;
Forming a nitride layer mainly composed of nitrogen on the surface of the electrical steel sheet; And
Forming a dielectric film for imparting tension on the nitride layer. The method according to claim 6,
The average thickness of the nitride layer is a method for producing a grain-oriented electrical steel sheet, characterized in that 2nm ~ 500nm. The method according to claim 6,
Formation of the nitride layer,
The electrical steel sheet is oriented electrical steel sheet, characterized in that the oxidation, hydrogen, nitrogen, ammonia and moisture in the atmosphere containing, by maintaining the oxidation capacity (P _H2O / P _H2 ) to 0.001 ~ 0.03, in the temperature range of 650 ℃ ~ 1,100 Manufacturing method. The method according to claim 6,
The insulating film is a method of manufacturing a grain-oriented electrical steel sheet, characterized in that consisting of aluminum hydroxide nanofibers and metal phosphate. The method according to claim 6,
The metal phosphate is a method for producing a grain-oriented electrical steel sheet, characterized in that the phosphate of at least one metal selected from the group consisting of alumina, magnesium, manganese and zinc. The method of claim 9,
Formation of the insulating film,
And coating the coating material consisting of the aluminum hydroxide nanofibers and the metal phosphate on the nitride layer, followed by heat treatment in a gas atmosphere mixed with hydrogen and nitrogen. The method of claim 11,
The heat treatment is a method for producing a grain-oriented electrical steel sheet, characterized in that for 5sec ~ 10 minutes at a temperature of 700 ℃ or more. The method of claim 11,
After the heat treatment, the dried insulating coating amount is 0.1 ~ 6.0g / m2 method for producing a grain-oriented electrical steel sheet characterized in that. The method according to claim 6,
The film adhesion of the electrical steel sheet is a manufacturing method of the grain-oriented electrical steel sheet, characterized in that 40mmΦ or less. The method according to claim 6,
The directional electrical steel sheet, % By weight Si: 1.0-7.0%, Sn: 0.01-0.6%, acid-soluble Al: 0.02-0.04%, Mn: 0.01-0.30%, C: 0.02-0.10%, S: 0.001-0.01%, balance Fe And other inevitable impurities.

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