KR101642826B1 - Non-orientied electrical steel sheet and method for producing the same - Google Patents

Abstract

A non-oriented electrical steel sheet and a manufacturing method thereof are disclosed. A method of manufacturing a non-oriented electrical steel sheet according to an embodiment of the present invention includes the steps of providing a slab containing 0.1% to 4% Si by weight, the balance Fe and impurities that are inevitably incorporated during the steelmaking process, The slab is heated and hot rolled to produce a hot-rolled steel sheet. The hot-rolled steel sheet is cold-rolled to produce a cold-rolled steel sheet. The cold-rolled steel sheet is finally annealed. , A zinc oxide, a nickel oxide, and an iron oxide.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-oriented electrical steel sheet,

Oriented electrical steel sheet and a method of manufacturing the same.

The nonoriented electric steel sheet is used as an iron core material in rotating devices such as motors, generators, and stationary devices such as small transformers, and plays an important role in determining the energy efficiency of electric devices.

The characteristics of the electric steel sheet include iron loss and magnetic flux density. The iron loss is small and the magnetic flux density is high, which is preferable. When the magnetic field is induced by adding electricity to the iron core, the lower the iron loss, And the higher the magnetic flux density, the larger the magnetic field can be induced with the same energy.

In order to reduce iron loss, Si, Al, Mn, etc., which are alloying elements with high resistivity, are added. This method has a problem that the iron loss is reduced but the saturation magnetic flux density is also decreased.

If the amount of Si added is 4% or more, the workability is lowered, which makes cold rolling difficult, resulting in a decrease in productivity and a large amount of Al and Mn. The more the addition is made, the lower the rolling property is, and the hardness is increased and the workability is lowered.

An embodiment of the present invention is to provide a non-oriented electrical steel sheet excellent in high frequency characteristics. Further, another embodiment of the present invention provides a method of manufacturing a non-oriented electrical steel sheet excellent in high frequency characteristics.

A method of manufacturing a non-oriented electrical steel sheet according to an embodiment of the present invention includes the steps of providing a slab containing 0.1% to 4% Si by weight, the balance Fe and impurities that are inevitably incorporated during the steelmaking process, The slab is heated and hot rolled to produce a hot-rolled steel sheet. The hot-rolled steel sheet is cold-rolled to produce a cold-rolled steel sheet. The cold-rolled steel sheet is finally annealed. , A zinc oxide, a nickel oxide, and an iron oxide.

The forming of the ferrite layer may be performed by mixing manganese oxide, zinc oxide, nickel oxide, and iron oxide with an electric steel plate coating solution.

The forming of the ferrite layer may be performed by mixing manganese oxide, zinc oxide, nickel oxide, and iron oxide with phosphates or polymers.

The step of forming the ferrite layer may be coating of manganese oxide, zinc oxide, nickel oxide and iron oxide by PVD, CVD, sputtering or PECVD.

Wherein the manganese oxide, the zinc oxide, the nickel oxide and the iron oxide are selected from the group consisting of manganese oxide: 26 mol% to 37 mol%, zinc oxide: 4 mol% to 11 mol%, nickel oxide: 2 mol% to 11 mol% The remainder may be iron oxide.

The ferrite layer formed in the step of forming the ferrite layer may have a thickness of 1 탆 to 30 탆.

The ferrite layer formed in the step of forming the ferrite layer may be formed on both surfaces of the electrical steel sheet.

The ferrite layer may further include silicon oxide, calcium oxide, vanadium oxide, zirconium oxide, molybdenum oxide, or a combination thereof.

The slab may further contain C: 0.05% or less (excluding 0%), N: 0.05% or less (excluding 0%), 0.1-3% Al and 0.01-0.5% Mn in weight percent.

And further subjecting the hot-rolled steel sheet to hot-rolled sheet annealing at 900 ° C to 1200 ° C.

The final annealing step may be performed at 800 ° C to 1200 ° C.

The non-oriented electrical steel sheet according to an embodiment of the present invention includes 0.1 to 4% by weight of Si, the balance of Fe and impurities which are inevitably incorporated during the steelmaking process, and at least one surface is coated with manganese oxide, zinc A ferrite layer including an oxide, a nickel oxide, and an iron oxide may be formed.

The ferrite layer may contain manganese oxide: 26 mol% to 37 mol%, zinc oxide: 4 mol% to 11 mol%, nickel oxide: 2 mol% to 11 mol%, and the balance may include iron oxide.

The ferrite layer may be formed to a thickness of 1 to 30 탆.

The ferrite layer may be formed on both surfaces of the electrical steel sheet.

The ferrite layer may further comprise silicon oxide, calcium oxide, vanadium oxide, zirconium oxide, molybdenum oxide, or a combination thereof.

The non-oriented electrical steel sheet may further contain 0.05% or less of C (excluding 0%), 0.05% or less (excluding 0%) of N, 0.1 to 3% of Al and 0.01 to 0.5% .

According to an embodiment of the present invention, a non-oriented electrical steel sheet having excellent iron loss at high frequency can be provided. Further, it is possible to provide a method for producing a non-oriented electrical steel sheet excellent in iron loss at high frequencies.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction 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.

Thus, in some embodiments, well-known techniques are not specifically described to avoid an undesirable interpretation of the present invention. Unless defined otherwise, all terms (including technical and scientific terms) used herein may be used in a sense commonly understood by one of ordinary skill in the art to which this invention belongs. Whenever a component is referred to as "including" an element throughout the specification, it is to be understood that the element may include other elements, not the exclusion of any other element, unless the context clearly dictates otherwise. Also, singular forms include plural forms unless the context clearly dictates otherwise.

The non-oriented electrical steel sheet according to an embodiment of the present invention may have a ferrite layer containing manganese oxide, zinc oxide, nickel oxide and iron oxide on one side or both sides of the steel sheet.

Also, the ferrite layer may contain manganese oxide: 26 mol% to 37 mol%, zinc oxide: 4 mol% to 11 mol%, based on 100 mol% of the manganese oxide, zinc oxide, nickel oxide, %, Nickel oxide: 2 mol% to 11 mol%, and the remainder may be iron oxide. When the manganese oxide, zinc oxide, and nickel oxide satisfy the above range, the saturation magnetic flux density can be improved and the iron loss property can be improved.

Also, the thickness of the ferrite layer may be 1 탆 to 30 탆. It is possible to provide an electrical steel sheet excellent in magnetism by forming a ferrite layer with a thickness of 1 탆 or more. If the thickness of the ferrite layer exceeds 30 占 퐉, the core workability may be deteriorated.

The ferrite layer may be formed on both surfaces of the electrical steel sheet.

The ferrite layer may further include silicon oxide, calcium oxide, vanadium oxide, zirconium oxide, molybdenum oxide, or a combination thereof.

The non-oriented electrical steel sheet may further contain 0.1 to 4% of Si, 0.05% or less of C (exclusive of 0%), 0.05% or less of N (exclusive of 0%), Al : 0.1 to 3%, and Mn: 0.01 to 0.5%.

Si plays a role of lowering the iron loss by increasing the resistivity. The effect of improving the iron loss of less than 0.1 wt% of silicon is not exhibited, and when it exceeds 4 wt%, the brittleness is increased. Therefore, the content of Si may be 0.1 wt% to 4 wt%.

If the content of C is more than 0.05% by weight, it may precipitate fine in the steel and interfere with the movement of the electric potential at the time of rolling, thereby deteriorating the rolling property. If the final product is left without being decarburized, It can harm magnetism. Therefore, the content of C may be 0.05 wt% or less.

If N is more than 0.05% by weight, it may interfere with the movement of the electric potential at the time of rolling, and it may be contained in a large amount in the final product, thereby impeding the movement of the magnetic domain in the AC magnetic field. Therefore, the content of N may be 0.05 wt% or less.

Al is an element that increases the resistivity. However, if it exceeds 3% by weight, the magnetic flux density may be drastically decreased, and if it is less than 0.1% by weight, the rolling property may be disadvantageously lowered.

Mn is an element that increases the specific resistance and reduces iron loss, but when it exceeds 0.5 wt%, the rolling property may be deteriorated. If it is less than 0.01% by weight, the iron loss may be lowered.

The ferrite layer may be a soft ferrite layer.

A method for producing a non-oriented electrical steel sheet as described above may be provided to produce the non-oriented electrical steel sheet as described above.

First, we provide slabs. The slabs provide a slab comprising from 0.1% to 4% Si, based on 100% by weight of the total slab composition, and the remainder comprising Fe and impurities that are inevitably incorporated during the steelmaking process.

The slab may further contain 0.05% or less of C (excluding 0%), 0.05% or less of N (excluding 0%), 0.1 to 3% of Al, and 0.01 to 0.5% of Mn in terms of% by weight.

The reason for elemental limitation is explained for the reason of the elemental limitation of the non-oriented electrical steel sheet, and further detailed explanation will be omitted.

The slab is heated and hot-rolled to produce a hot-rolled steel sheet. Further, after the hot-rolled steel sheet is manufactured, it may further include a step of annealing the hot-rolled steel sheet at 900 ° C to 1200 ° C. The hot-rolled steel sheet is cold-rolled to produce a cold-rolled steel sheet, and then final annealing is performed. At this time, the final annealing temperature may be 800 ° C to 1200 ° C.

Thereafter, a ferrite layer containing manganese oxide, zinc oxide, nickel oxide, and iron oxide is formed on the steel sheet after completion of the final annealing.

The step of forming the ferrite layer may be performed by mixing the manganese oxide, zinc oxide, nickel oxide, and iron oxide in powder form into an electrical steel plate insulating coating solution and then applying heat treatment.

The electrical steel sheet coating solution may be an insulating coating solution, and the insulating coating solution may include an organic silane, an epoxy resin, a metal chelate compound, and a colloidal inorganic compound. Further, components including organic resin emulsions such as a phosphate, a chromate, and the like, and a vinyl acetate, a butadiene-styrene copolymer, an acrylic resin and the like can be exemplified. Since the insulating coating liquid of the non-oriented electrical steel sheet is well known to those skilled in the art, further detailed explanation is omitted.

Alternatively, the step of forming the ferrite layer may be performed by CVD, PVD, HVOF (High Velocity Oxy-Fuel), or an ordinary-temperature vacuum spray ceramic coating method.

In the step of forming the ferrite layer, the content of manganese oxide: 26 mol% to 37 mol%, zinc oxide: 4, based on 100 mol% of the manganese oxide, the zinc oxide, the nickel oxide, mol% to 11 mol%, nickel oxide: 2 mol% to 11 mol%, and the remainder may be iron oxide.

When the manganese oxide, zinc oxide, and nickel oxide satisfy the above range, the saturation magnetic flux density can be improved and the iron loss property can be improved.

Also, the thickness of the ferrite layer may be 1 탆 to 30 탆. It is possible to provide an electrical steel sheet excellent in magnetism by forming a ferrite layer with a thickness of 1 탆 or more. If the thickness of the ferrite layer exceeds 30 占 퐉, the core workability may be deteriorated.

Further, at least one of silicon oxide, calcium oxide, vanadium oxide, zirconium oxide, and molybdenum oxide may be coated or coated in addition to manganese oxide, zinc oxide, nickel oxide and iron oxide.

Hereinafter, examples will be described in more detail. The following examples are illustrative of the present invention only and are not intended to limit the scope of the present invention.

[Example 1]

The slab containing 3.15% of Si, 0.7% of Al, 0.2% of Mn, 0.005% of C and 0.006% of N and the balance of Fe and impurities was heated to a thickness of 2 mm by hot rolling Respectively. The hot-rolled sheet was then annealed at 1050 ° C for 3 minutes.

The steel sheet was then cold-rolled to a thickness of 0.15 mm.

Thereafter, the cold-rolled sheet was finally annealed in a mixed atmosphere of nitrogen and hydrogen at 1050 占 폚 for 3 minutes, and the magnetic property was measured to make the comparative member 1. [

Then, manganese oxide, zinc oxide, nickel oxide, and iron oxide were mixed with the insulating coating solution in the same amount as shown in Table 1 on the surface of the annealed sheet, and then heat treated to form a ferrite layer.

In Table 1, the thickness of the ferrite layer is the sum of thicknesses applied to both surfaces of the steel sheet. The thicker the ferrite layer, the smaller the magnetic flux density, but the iron loss measured at 400 Hz was greatly improved. However, when the coating thickness was 35 탆, the thickness of the entire steel sheet became thicker, and the magnetic properties were lower than that of the coating thickness of 25 탆, and the surface layer partially peeled off during core processing.

[Example 2]

The slab containing 3.0% by weight of Si, 1.1% by weight of Al, 0.3% by weight of Mn, 0.002% by weight of C and 0.001% by weight of N and the balance of Fe and impurities was heated and hot-rolled to a thickness of 2 mm. The hot-rolled sheet was then annealed at 1050 ° C for 3 minutes. And then cold-rolled to a thickness of 0.15 mm.

Thereafter, final annealing was performed in a mixed atmosphere of nitrogen and hydrogen at 1050 캜 for 3 minutes, and the magnetic property was measured to obtain a comparative member 1.

Then, manganese oxide, zinc oxide, nickel oxide and iron oxide were mixed with the insulating coating solution in the same amount as shown in Table 2 on the surface of the steel sheet, followed by coating heat treatment to form a ferrite layer.

In Table 2, the coating thickness is the sum of thicknesses applied on the upper and lower surfaces. The thicker the ferrite layer, the smaller the magnetic flux density, but the iron loss measured at 400 Hz was greatly improved. However, when the coating thickness was 35 탆, the thickness of the entire material was thicker than that of the case where the coating thickness was 25 탆, and the surface layer was partially peeled off during core processing.

While the present invention has been described in connection with certain exemplary embodiments, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims.

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 defined by the appended 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 interpreted as being included in the scope of the present invention .

Claims (13)

Heating the slab and then hot rolling to produce a hot-rolled steel sheet;
Cold-rolling the hot-rolled steel sheet to produce a cold-rolled steel sheet;
Final annealing the cold-rolled steel sheet; And
And forming a ferrite layer including manganese oxide, zinc oxide, nickel oxide, and iron oxide on at least one surface of the cold rolled steel sheet,
The slab may contain 0.1 to 4% of Si, 0.05% or less (excluding 0%) of C, 0.05% or less (excluding 0%) of N, 0.1 to 3% of Al, 0.01 to 0.5% of Mn, the balance comprising Fe and unavoidable impurities,
Wherein the ferrite layer contains manganese oxide: 26 mol% to 37 mol%, zinc oxide: 4 mol% to 11 mol%, nickel oxide, nickel oxide, and nickel oxide based on 100 mol% An oxide: 2 mol% to 11 mol%, and the balance being iron oxide.
The method according to claim 1,
Wherein forming the ferrite layer comprises:
Wherein the manganese oxide, zinc oxide, nickel oxide, and iron oxide are mixed and coated in an insulating coating solution.
The method according to claim 1,
Wherein forming the ferrite layer comprises:
CVD, PVD, HVOF (High Velocity Oxy-Fuel), or room temperature vacuum spray ceramic coating method.
delete The method according to claim 1,
Wherein the ferrite layer formed in the step of forming the ferrite layer has a thickness of 1 mu m to 30 mu m.
6. The method of claim 5,
Wherein the ferrite layer formed in the step of forming the ferrite layer is formed on both surfaces of the electrical steel sheet.
The method according to claim 6,
Wherein the ferrite layer further comprises silicon oxide, calcium oxide, vanadium oxide, zirconium oxide, molybdenum oxide, or a combination thereof.
delete A non-oriented electrical steel sheet having a ferrite layer containing manganese oxide, zinc oxide, nickel oxide, and iron oxide on one surface or both surfaces of the steel sheet,
The steel sheet comprises 0.1 to 4% of Si, 0.05% or less of C (exclusive of 0%), 0.05% or less of N (exclusive of 0%), 0.1 to 3% of Al, and Mn 0.01 to 0.5%, the balance comprising Fe and unavoidable impurities,
Wherein the ferrite layer is composed of a non-oriented electrical steel sheet containing 26 to 37 mol% of manganese oxide, 4 to 11 mol% of zinc oxide, 2 to 11 mol% of nickel oxide, .

delete 10. The method of claim 9,
Wherein the thickness of the ferrite layer is 1 占 퐉 to 30 占 퐉.
12. The method of claim 11,
Wherein the ferrite layer further comprises silicon oxide, calcium oxide, vanadium oxide, zirconium oxide, molybdenum oxide, or a combination thereof.
delete