KR102560533B1 - Electrical steel steet adhesive composition, electrical steel steet laminate and manufacturing method for the same - Google Patents

Abstract

In the electrical steel sheet laminate according to an embodiment of the present invention, two or more electrical steel sheets are laminated, an adhesive layer is interposed between the electrical steel sheets, and the adhesive layer includes at least one of tar and asphalt.

Description

Electrical steel laminate and manufacturing method thereof

An embodiment of the present invention relates to an electrical steel sheet adhesive composition, an electrical steel sheet laminate, and a manufacturing method thereof. More specifically, it relates to a method for manufacturing an electrical steel sheet laminate in which high-frequency iron loss is improved by reducing the thickness of the electrical steel sheet.

In general, non-oriented electrical steel sheet is an important iron core material required to convert electrical energy into mechanical energy in a rotating machine, and it is important to have magnetic properties, that is, low iron loss, in order to save energy. Here, iron loss is energy lost by being converted to heat during the energy conversion process, so the lower the iron loss, the more efficient it is.

Recently, technology for converting existing internal combustion engine vehicles into HEV (hybrid vehicles) / EV (electric vehicles) is rapidly developing as a countermeasure for fossil fuel shortage and greenhouse gas reduction. These HEV/EVs are vehicles that convert some or all of their driving methods to electric motors to achieve better fuel efficiency while reducing the use of gasoline or diesel, which are conventional internal combustion engine fuels.

A motor used in such a vehicle rotates at high speed during high-speed driving. Therefore, the non-oriented electrical steel sheet, which is the core material of the motor, should have low high-frequency iron loss during high-speed rotation. In general, high-frequency iron loss means iron loss at a frequency of 200 Hz or more, but a value of W _10/400 is usually used in non-oriented electrical steel sheets for automobiles.

In addition, in the field of home appliances, iron loss in the high-frequency iron loss range is becoming increasingly important due to the adoption of BLDC motors. In order to improve the high-frequency iron loss, the alloy elements such as Si, Al, and Mn, which are non-resistive elements of the electrical steel sheet, must be increased, impurities must be reduced to facilitate the movement of magnetic domains, and the thickness of the electrical steel sheet must be thinned.

However, when non-magnetic alloy elements such as Si, Al, and Mn are contained in high amounts, rolling becomes difficult and has limitations, and when the thickness is thinned, there is a difficulty in increasing the production cost and the processing cost on the customer side.

To solve this problem, a so-called sandwich steel sheet in which an adhesive layer is interposed between electrical steel sheets and additionally rolled is proposed. However, inorganic materials such as Al ₂ O ₃ and AlN have been proposed as an adhesive layer, and these inorganic materials have a disadvantage in that they have poor adhesive strength and require high heat treatment for adhesion, increasing equipment and process costs.

In addition, since the inorganic material has low elasticity during winding, the adhesive layer is broken, making it impossible to wind the inorganic material.

An embodiment of the present invention is to provide an electrical steel sheet adhesive composition, an electrical steel sheet laminate, and a manufacturing method thereof. More specifically, it is intended to provide a manufacturing method of an electrical steel sheet laminate that improves high-frequency core loss by reducing the thickness of the electrical steel sheet.

An electrical steel sheet adhesive composition according to an embodiment of the present invention includes at least one of tar and asphalt.

One or more of an epoxy resin, a urethane resin, an ester resin, an acrylic resin, a polyimide resin, and a polyethylene resin may be further included.

One or more of Al ₂ O ₃ , AlN, SiO ₂ , BN, MgO, and ZrO ₂ may be further included.

5 to 30% by weight of at least one of tar and asphalt may be included.

In the electrical steel sheet laminate according to an embodiment of the present invention, two or more electrical steel sheets are laminated, an adhesive layer is interposed between the electrical steel sheets, and the adhesive layer includes at least one of tar and asphalt.

Each electrical steel sheet may have a thickness of 0.3 mm or less.

The thickness of the laminate may be 0.3 to 0.5 mm.

The thickness of the adhesive layer may be 0.3 μm or more.

The electrical steel sheet laminate according to an embodiment of the present invention may further include an insulating film positioned on the outermost surface of the electrical steel sheet.

Electrical steel sheet, in weight %, respectively: Si: 3.5% or less (excluding 0%), Al: 2.5% or less (excluding 0%), Mn: 3% or less (excluding 0%), P: 0.1% or less (excluding 0%), C: 0.04% or less (excluding 0%), S: 0.01% or less (excluding 0%), and N: 0.01% or less (excluding 0%) and the balance may include Fe and other unavoidable impurities.

A method of manufacturing an electrical steel sheet laminate according to an embodiment of the present invention includes the steps of hot rolling a slab to prepare a hot rolled sheet; Cold-rolling a hot-rolled sheet to produce a cold-rolled sheet; Laminating cold-rolled sheets by inserting an adhesive composition in the middle of each layer; Re-cold-rolling the laminated cold-rolled sheet to prepare a multi-layer cold-rolled sheet and final annealing of the multi-layer cold-rolled sheet, and the adhesive composition may include at least one of tar and asphalt.

In the step of manufacturing a multi-layer cold-rolled sheet by re-cold rolling, the reduction ratio may be 5 to 10%.

By manufacturing an electrical steel sheet laminate according to an embodiment of the present invention, it is possible to finally provide an electrical steel sheet laminate excellent in high frequency characteristics and strength at the same time.

When an electrical steel sheet laminate is made in a laminated structure according to an embodiment of the present invention, iron loss and strength characteristics are improved compared to conventional electrical steel sheets having the same components.

The electrical steel sheet laminate according to an embodiment of the present invention can contribute to improving the efficiency of a BLDC motor or an automobile drive motor driven at high frequency.

1 is a schematic view of a cross section of an electrical steel sheet laminate according to an embodiment of the present invention.
2 is a schematic diagram of a manufacturing process of an electrical steel sheet laminate according to an embodiment of the present invention.

In this specification, terms such as first, second, and third are used to describe various parts, components, regions, layers, and/or sections, but are not limited thereto. These terms are only used to distinguish one part, component, region, layer or section from another part, component, region, layer or section. Accordingly, a first part, component, region, layer or section described below may be referred to as a second part, component, region, layer or section without departing from the scope of the present invention.

In this specification, when a certain component is said to "include", it means that it may further include other components, not excluding other components unless otherwise stated.

In this specification, the technical terms used are only for referring to specific embodiments and are not intended to limit the present invention. As used herein, the singular forms also include the plural forms unless the phrases clearly indicate the opposite. The meaning of "comprising" as used herein specifies particular characteristics, regions, integers, steps, operations, elements and/or components, and does not exclude the presence or addition of other characteristics, regions, integers, steps, operations, elements and/or components.

In this specification, the term "combination of these" included in the expression of the Markush form means a mixture or combination of one or more selected from the group consisting of the components described in the expression of the Markush form, and includes one or more selected from the group consisting of the components.

In this specification, when a part is referred to as being “on” or “on” another part, it may be directly on or on the other part or may be followed by another part therebetween. In contrast, when a part is said to be “directly on” another part, there is no intervening part between them.

Although not defined differently, all terms including technical terms and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention belongs. Terms defined in commonly used dictionaries are additionally interpreted as having meanings consistent with related technical literature and currently disclosed content, and are not interpreted in ideal or very formal meanings unless defined.

In addition, unless otherwise indicated, % means weight%, and 1ppm is 0.0001 weight%.

In one embodiment of the present invention, the meaning of further including an additional element means replacing and including iron (Fe) as much as the additional amount of the additional element.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein.

An electrical steel sheet adhesive composition according to an embodiment of the present invention includes at least one of tar and asphalt.

Tar and asphalt not only have excellent adhesiveness, but also can secure insulation between steel plates. Furthermore, even when heat-treated at a relatively low temperature, curing is possible, elasticity is maintained, winding is possible after lamination, and the adhesive layer is not destroyed during subsequent punching.

Tar is a residue made during the decomposition and distillation of tree sap. Residues separated from coal are classified as coal tar, and residues separated from wood as wood tar.

Asphalt refers to the residue remaining after light oil is removed from the components constituting petroleum.

In the electrical steel sheet adhesive composition, 5 to 30% by weight of tar and asphalt may be included. If too little tar and asphalt are included, the above-mentioned bonding performance cannot be obtained adequately. If too much tar and asphalt are included, the thickness becomes excessively thick, and cracking problems may occur during winding. More specifically, 15 to 25% by weight of tar and asphalt may be included. When tar and asphalt are included alone, the content of the sole means, and when tar and asphalt are included at the same time, the total amount may be included in the aforementioned range.

The electrical steel sheet adhesive composition may further include at least one of an epoxy resin, a urethane resin, an ester resin, an acrylic resin, a polyimide resin, and a polyethylene resin. Each of the resins is a resin containing an epoxy group, a urethane group, an ester group, an acryl group, an imide group, and an ethylene group, and since they are widely known, detailed descriptions thereof will be omitted.

By further including these resins, adhesion between steel plates can be further improved and high-frequency iron loss can be improved.

When these resins are further included, they may be included in an amount of 1 to 20% by weight based on 100% by weight of the electrical steel adhesive composition. When too much resin is included, the content of tar and asphalt is relatively low, and thus adhesion may be deteriorated. More specifically, the resin may be included in an amount of 5 to 15 wt % based on 100 wt % of the electrical steel adhesive composition.

The electrical steel sheet adhesive composition may further include one or more of Al ₂ O ₃ , AlN, SiO ₂ , BN, MgO, and ZrO ₂ . By adding these inorganic components, adhesive force can be reinforced and insulation can be ensured at the same time.

When these inorganic components are further included, they may be included in an amount of 1 to 20% by weight based on 100% by weight of the electrical steel adhesive composition. When the inorganic component is included too much, the content of tar and asphalt is relatively low, and thus the adhesiveness may be deteriorated. More specifically, the resin may be included in an amount of 5 to 15 wt % based on 100 wt % of the electrical steel adhesive composition.

In addition, the electrical steel sheet adhesive composition may further include a solvent. The solvent enables the electrical steel sheet adhesive composition to be easily applied to the surface of the electrical steel sheet. The solvent may be included as a remainder other than the above-mentioned components. More specifically, 70 to 95% by weight may be included.

Specifically, the solvent may include water or alcohol.

1 schematically shows a cross section of an electrical steel sheet laminate according to an embodiment of the present invention. As shown in FIG. 1, in the electrical steel sheet laminate 100 according to an embodiment of the present invention, two or more electrical steel sheets 10 are laminated, an adhesive layer 20 is interposed between the electrical steel sheets 10, and the adhesive layer 20 includes at least one of tar and asphalt. Although FIG. 1 shows an example in which the electrical steel sheet 10 is laminated in two layers, it is not limited thereto and may be laminated in three or four layers.

Hereinafter, each configuration will be described in detail.

The electrical steel sheet 10 may be a non-oriented electrical steel sheet or a grain-oriented electrical steel sheet. More specifically, it may be a non-oriented electrical steel sheet.

In one embodiment of the present invention, the effect is expressed by the components of the adhesive layer and the lamination process regardless of the alloy composition of the electrical steel sheet 10 . Hereinafter, alloy components of the electrical steel sheet 10 will be supplementarily described.

The electrical steel sheet 10, in weight %, respectively, Si: 3.5% or less (excluding 0%), Al: 2.5% or less (excluding 0%), Mn: 3% or less (excluding 0%), P: 0.1% or less (excluding 0%), C: 0.04% or less (excluding 0%), S: 0.01% or less (excluding 0%), and N: 0.01% or less (0% excluding), and the balance may include Fe and other unavoidable impurities. In one embodiment of the present invention, two or more electrical steel sheets 10 exist, and the alloy components of each electrical steel sheet 10 may be different.

Si: 3.5% by weight or less

Silicon (Si, silicon) serves to lower the iron loss by increasing the specific resistance of the material, and when too much is added, the hardness of the material increases and productivity and punching performance may be inferior. More specifically, 2.0 to 3.5% by weight of Si may be included.

Al: 2.5% by weight or less

Aluminum (Al) increases the specific resistance of the material, lowers iron loss, and suppresses the formation of fine nitrides. However, if too much is added, problems may occur in all processes such as steelmaking, continuous casting, and hot rolling, thereby greatly reducing productivity. More specifically, 0.5 to 2.0% by weight of Al may be included.

Mn: 3% by weight or less

Manganese (Mn) serves to improve iron loss by increasing the specific resistance of the material and form sulfides, and when added in an excessive amount, magnetic flux density may decrease. More specifically, 0.5 to 2.5% by weight of Mn may be included.

P: 0.1% by weight or less

Phosphorus (P) is mostly dissolved in steel to show the effect of improving iron loss, but if it is contained too much, it is undesirable because it is segregated at the grain boundary and lowers the toughness of the material, resulting in inferior productivity and punchability.

More specifically, 0.005 to 0.05% by weight of P may be included.

C: 0.04% by weight or less

Carbon (C) is an effective element for increasing strength, but when it is included too much, the reduction of magnetism is greater than the effect of increasing strength. More specifically, C may be included in an amount of 0.01% by weight or less. More specifically, C may be included in an amount of 0.005% by weight or less.

S: 0.01% by weight or less

Sulfur (S) is preferably managed at a low level because it forms fine precipitates such as MnS and CuS to deteriorate magnetic properties. More specifically, S may be included in an amount of 0.005% by weight or less.

N: 0.01% by weight or less

Nitrogen (N) forms fine and long AlN precipitates inside the base material to suppress crystal grain growth and deteriorate iron loss, so it is preferable to contain nitrogen (N) as little as possible. More specifically, N may be included in an amount of 0.005% by weight or less.

Other unavoidable impurity elements

In addition to the above impurity elements, impurities such as Ti and Nb that are unavoidably incorporated may be included. Since Ti and Nb promote the growth of the [111] texture, which is an undesirable crystal orientation in electrical steel sheets, they can be limited to 0.004 wt% or less (excluding O%), more specifically, 0.002 wt% or less (excluding O%).

In addition to the above-mentioned elements, the remainder may be Fe. In one embodiment of the present invention, the addition of additional elements in addition to the above-mentioned elements is not excluded, and when additional elements are included, they may be added in place of Fe.

Each electrical steel sheet 10 may have a thickness of 0.3 mm or less. In one embodiment of the present invention, even if the electrical steel sheet 10 is thinned, the overall thickness of the laminate 100 is similar to that of the existing electrical steel sheet, so that the customer's processing cost is not increased. At the same time, there is an effect of improving high-frequency iron loss through thinning. More specifically, the electrical steel sheet 10 may have a thickness of 0.1 to 0.3 mm.

The adhesive layer 20 is interposed between the electrical steel sheets 10 to adhere the electrical steel sheets to each other. In one embodiment of the present invention, the adhesive layer 20 includes at least one of tar and asphalt. Through this, the elastic force is maintained in the adhesive layer 20, so that winding after lamination is possible, and the adhesive layer is not destroyed even when punched out later. In addition, insulation between the electrical steel sheets 10 may be secured.

The adhesive layer 20 is formed by applying the above-described adhesive composition to the surface of the electrical steel sheet 10 and heat-treating it, and has the same components as the above-described adhesive composition. Since this has been described above, duplicate descriptions will be omitted.

However, volatile components such as solvents in the adhesive composition are removed through heat treatment, and component ratios in the adhesive layer 20 may be different from those in the adhesive composition.

That is, when the adhesive composition is composed of at least one of tar and asphalt and a solvent and does not contain any additional components, the adhesive layer 20 may be composed of only at least one of tar and asphalt from which volatile components are removed.

In the case of additionally including a resin and an inorganic component, 50 to 90% by weight of one or more of tar and asphalt, 5 to 25% by weight of one or more of epoxy resin, urethane resin, ester resin, acrylic resin, polyimide resin, and polyethylene resin, 5 to 25% by weight of one or more of Al ₂ O ₃ , AlN, SiO ₂ , BN, MgO and ZrO ₂ , based on 100% by weight of the adhesive layer 20. 25% by weight. The adhesive layer 20 may have a thickness of 0.3 μm or more. If the thickness of the adhesive layer is too thin, a problem may occur in adhesiveness. The thicker the adhesive layer 20, the better the adhesiveness, but there is a limit, and the thicker the adhesive layer 20, the smaller the spotting ratio, so the upper limit may be 1.0 μm. More specifically, the adhesive layer 20 may have a thickness of 0.4 μm to 0.7 μm.

The thickness of the laminate may be 0.3 to 0.5 mm. If the thickness of the laminate is too thin, energy and process are excessively consumed for rolling, and if the thickness is too thick, properties unsuitable for high frequency may appear. More specifically, it may be 0.35 to 0.45 mm.

The electrical steel sheet laminate 100 according to an embodiment of the present invention may further include an insulating film 30 positioned on the outermost surface of the electrical steel sheet 10 . The insulating film 30 may be located on a surface opposite to the surface where the electrical steel sheet 10 and the adhesive layer 20 are in contact.

Since the insulating film 30 is widely known, a detailed description thereof will be omitted.

2 schematically shows a manufacturing method of an electrical steel sheet laminate according to an embodiment of the present invention.

A method of manufacturing an electrical steel sheet laminate according to an embodiment of the present invention includes the steps of hot rolling a slab to prepare a hot rolled sheet; Cold-rolling a hot-rolled sheet to produce a cold-rolled sheet; Laminating cold-rolled sheets by inserting an adhesive composition in the middle of each layer; Re-cold-rolling the laminated cold-rolled sheet to produce a multi-layer cold-rolled sheet, and finally annealing the multi-layer cold-rolled sheet.

Hereinafter, each step is described in detail.

First, a hot-rolled sheet is manufactured by hot-rolling a slab. Since the alloy components of the slab have been described in relation to the alloy components of the electrical steel sheet 10 described above, overlapping descriptions will be omitted. Since there is no substantial change in alloy components during the manufacturing process of the laminate, the alloy components of the slab and the electrical steel sheet 10 are substantially the same.

Before hot rolling the slab, the molten steel is first solidified in a continuous casting process to manufacture the slab. The slab is charged into a heating furnace and reheated at 1,050 ° C to 1,200 ° C.

Since it is desirable to reheat at a temperature as low as possible in order to prevent re-dissolution of precipitates during reheating, it is necessary to heat at 1,200 ° C or less, and it is difficult to roll because the deformation resistance is too large during hot rolling at less than 1,050 ° C.

During hot rolling, the thickness can be 2.5 mm or less. This is to minimize the unfavorable (111) recrystallized texture when the cold reduction ratio is high later.

After manufacturing the hot-rolled sheet, an annealing step may be further included. If the hot-rolled sheet annealing temperature is less than 850 ° C, the structure does not grow or grows finely, so the effect of increasing the magnetic flux density is small, and if the annealing temperature exceeds 1,150 ° C, the magnetic properties are rather deteriorated, and the rolling workability may be deteriorated due to deformation of the plate shape. Therefore, the temperature range can be limited to 850 to 1,150 ° C. More specifically, the annealing temperature of the hot-rolled sheet may be 950 to 1,150 °C.

Next, the hot-rolled sheet is cold-rolled to manufacture a cold-rolled sheet. The hot-rolled sheet may be pickled beforehand. The cold-rolled sheet may have a thickness of 1 mm or less. It is possible to bond two layers immediately after pickling without cold rolling, but in that case, since the roughness of the pickling surface is high, the insulation by the intermediate adhesive may be destroyed during subsequent rolling.

Next, the cold-rolled sheets are laminated, but laminated by inserting an adhesive composition in the middle of each layer. Since the adhesive composition is the same as that described above, overlapping descriptions will be omitted.

Next, the laminated cold-rolled sheet is re-cold-rolled to manufacture a multilayer cold-rolled sheet. In order for the laminate to have a uniform thickness, a re-cold rolling process is required. Re-cold rolling has a reduction ratio of 5 to 10%, and is different from simple pressing in which thickness variation does not substantially occur. At this time, the reduction ratio is calculated as ([thickness of the laminate before rolling] - [thickness of the laminate after rolling])/[thickness of the laminate before rolling].

to the next. The multi-layer cold-rolled sheet is subjected to final annealing. The final annealing temperature may be 500 to 1050 °C. If the final annealing temperature is less than 500 ° C, recrystallization does not occur sufficiently, and if the final annealing temperature exceeds 1,050 ° C, tar and asphalt are reduced to CO ₂ .

At this time, the atmosphere of the final annealing is a mixed gas atmosphere in which 20% of hydrogen and 80% of nitrogen is mixed, and the annealing time is preferably 1 minute or more.

After final annealing, a step of re-cold rolling may be further included.

Thereafter, a step of forming an insulating film on the outermost surface of the laminate may be further included.

Hereinafter, the present invention will be described in more detail through examples. However, it should be noted that the following examples are only for illustrating the present invention in more detail, and are not intended to limit the scope of the present invention. This is because the scope of the present invention is determined by the matters described in the claims and the matters reasonably inferred therefrom.

Example

A slab composed of Si 3.1%, Al 0.9%, Mn 0.3%, N 0.002%, C 0.003%, P 0.01%, S 0.002%, N 0.0015% and other unavoidable impurities in weight percent was reheated and then hot rolled to 2.0mmt. The hot-rolled sheet was annealed and pickled at 1100 ° C., then cold-rolled to 0.27 mm, and then the adhesive composition summarized in Table 1 was applied, and the two substrates were weakly rolled at a reduction ratio of about 8%. Except for the components listed in Table 1, it is water.

Thereafter, after drying at around 100 ° C. for 15 seconds, final annealing was performed at 1050 ° C. for 2 minutes at 20% hydrogen and 80% nitrogen.

High-frequency iron loss (W _10/400 ) was measured by RC average. The adhesive strength was measured before and after stress relief annealing using a device that measures the tensile force of the stacked samples while pulling at a constant speed after fixing the laminate to the upper and lower jigs (JIG) after treatment at 1100 ° ^C. for 2 minutes N ₂ with a constant force. At this time, the measured value was measured at the point at which the interface with the minimum adhesive strength was eliminated among the interfaces of the stacked samples. Passed when it was more than 0.1MPa, and failed when it was less than 0.1MPa.

Whether or not the adhesive layer is damaged during winding is summarized in Table 2 by winding the steel sheet to a diameter of at least 1 m and observing whether the adhesive layer is damaged at this time.

Tar (manufactured by POSCO Chemtech)/
Asphalt (manufactured by Dongwoo Chemical) profit
(manufactured by Dow) inorganic ingredients
(Akzo Nobel Rebasil) Example 1 Tar: 20% by weight - - Example 2 Asphalt: 20% by weight - - Example 3 Tar: 10% by weight Example 4 Tar: 40% by weight Example 5 20% by weight of tar 2% by weight of polyethylene Example 6 20% by weight of tar 2% by weight polypropylene Example 7 20% by weight of tar 2% by weight polyacetate Comparative Example 1 - Epoxy resin: 20% by weight - Comparative Example 2 - - Al ₂ O ₃ : 20% by weight Comparative Example 3 - - SiO ₂ : 20% by weight

adhesive composition adhesive layer thickness
(μm) Laminate iron loss (W10/400, W/kg) adhesiveness Whether or not the adhesive layer is damaged during winding Invention Steel 1 Example 1 0.4 8.1 pass X Invention Steel 2 Example 2 0.4 8.1 pass X Comparative Lecture 1 fault 13.8 doesn't exist - comparative steel 2 Comparative Example 1 0.4 8.2 fail X comparative lecture 3 Comparative Example 2 0.4 10.3 pass O comparative lecture 4 Comparative Example 3 0.4 14.1 pass O Invention Steel 3 Example 3 0.1 11.0 pass X Invention Steel 4 Example 4 0.1 10.9 pass X comparative steel 5 Comparative Example 1 0.1 10.3 fail X invention steel 5 Example 5 0.4 8.1 pass X invention steel 6 Example 6 0.4 8.1 pass X invention steel 7 Example 7 0.4 8.1 pass X

As can be seen in Tables 1 and 2, when using the adhesive composition according to an embodiment of the present invention, it can be seen that the high frequency iron loss is improved compared to Comparative Steel 1 formed as a single layer without an adhesive layer. In addition, it can be confirmed that high-frequency iron loss and adhesion are improved compared to comparative steels 3 and 4 made of inorganic components. In addition, it can be confirmed that the high-frequency iron loss and adhesion are excellent compared to the comparative steel 2 made of only resin.

It can be seen that the inventive steels 3 and 4, which did not form a sufficient thickness of the adhesive layer, showed some inferior adhesiveness compared to the inventive steels 1 and 2.

The present invention is not limited to the above embodiments, but can be manufactured in various different forms, and those skilled in the art to which the present invention pertains do not change the technical spirit or essential features of the present invention. It will be understood that it can be implemented in other specific forms. Therefore, the embodiments described above should be understood as illustrative in all respects and not limiting.

100: electrical steel laminate, 10: electrical steel,
20: adhesive layer, 30: insulating film

Claims (12)

delete delete delete delete Two or more electrical steel sheets are laminated,
An adhesive layer is interposed between the electrical steel sheets,
The adhesive layer is an electrical steel sheet laminate comprising at least one of tar and asphalt. According to claim 5,
The electrical steel sheet laminate having a thickness of each of the electrical steel sheets is 0.3 mm or less. According to claim 5,
The electrical steel sheet laminate having a thickness of the entire laminate is 0.3 to 0.5 mm. According to claim 5,
An electrical steel sheet laminate having an adhesive layer thickness of 0.3 μm or more. According to claim 5,
An electrical steel sheet laminate further comprising an insulating film positioned on the outermost surface of the electrical steel sheet. According to claim 5,
The electrical steel sheet, in weight %, respectively, Si: 3.5% or less (excluding 0%), Al: 2.5% or less (excluding 0%), Mn: 3% or less (excluding 0%), P: 0.1% or less (excluding 0%), C: 0.04% or less (excluding 0%), S: 0.01% or less (excluding 0%), and N: 0.01% or less (excluding 0%) ), and the balance includes Fe and other unavoidable impurities. Preparing a hot-rolled sheet by hot-rolling the slab;
manufacturing a cold-rolled sheet by cold-rolling the hot-rolled sheet;
Laminating the cold-rolled sheets by inserting an adhesive composition in the middle of each layer;
Re-cold-rolling the laminated cold-rolled sheet to produce a multi-layer cold-rolled sheet; and
Including the step of final annealing the multi-layer cold-rolled sheet,
The adhesive composition is a manufacturing method of an electrical steel sheet laminate comprising at least one of tar and asphalt. According to claim 11,
In the step of producing a multi-layer cold-rolled sheet by re-cold rolling, the reduction ratio is 5 to 10%.