KR20170074608A - Grain oriented electrical steel sheet and manufacturing method for the same - Google Patents

Abstract

The grain-oriented electrical steel sheet according to an embodiment of the present invention may contain 2.0% to 5.0% of Si, 0.005% to 0.04% of Al, 0.01% to 0.2% of Mn, 0.005% to 0.05% of N, 0.005% or less (excluding 0%), P: 0.0005% to 0.045%, Co: 0.1% to 3.0%, and the balance Fe and other unavoidable impurities.

Description

TECHNICAL FIELD The present invention relates to a grain-oriented electrical steel sheet and a method of manufacturing the same. BACKGROUND ART [0002]

To a directional electric steel sheet and a manufacturing method thereof.

The directional electric steel sheet is a soft magnetic material used as an iron core of a stopper which requires excellent one-directional magnetic properties such as a transformer and a reactor, and a Goss {110} <001> texture is formed by secondary recrystallization using a crystal growth inhibitor And the < 001 > direction, which is an easy direction of magnetization of iron, coincides with the rolling direction and has excellent magnetic properties in the rolling direction. The magnetic properties include magnetic flux density and iron loss, and the higher the degree of orientation of the < 001 > direction with respect to the rolling direction, the better the magnetic property. Directional electrical steel sheet requires low iron loss in order to reduce electric power loss of electric equipment. Iron loss is higher when the steel sheet thickness and impurity amount are lower, magnetic flux density and specific resistance are higher, magnetic domain width is smaller, The method of micronization has a high improvement effect. As for the method of miniaturization of the magnetic domain, it is possible to classify the temporary magnetic domain microfabrication and the permanent magnetic domain microfabrication according to whether or not the improvement effect of magnetic domain refinement is maintained even after the stress relief annealing.

Temporal magnetic microfabrication is a technique of miniaturizing a 180 ° magnetic domain by forming a 90 ° magnetic domain to minimize self-elastic energy generated by applying local stress to the surface by thermal energy or mechanical energy. There is a temporary magnetic domain refinement method using a laser, a ball scratch, a plasma, and an electron beam in accordance with an energy source for making the magnetic domains finer. In the method of microminiaturization of the temporary magnetic domain, input energy is required to be increased in order to control the compression deformation region of the steel sheet, and thus surface coating damage can not be avoided in the microfabrication process.

Unlike the miniaturization of the temporary magnetic domain, the effect of improving the iron loss can be maintained even after the heat treatment, and there are an etch method, a roll method, and a laser method for the permanent magnetic microfabrication method which can be used not only as an iron core but also as an iron core material for a coil core. The etching method is difficult to control the groove shape because the grooves are formed on the surface of the steel sheet by an electrochemical corrosion reaction with an acid solution, and it is not environmentally friendly because an acid solution is used.

The method of refining permanent magnetic beads by a roll is a method of refining a magnetic domain by forming a groove having a constant width and depth on the surface of a steel sheet by pressing a roll formed in a projection shape and recrystallizing the bottom of the groove through an annealing process, There is a lack of stability and reliability in machining and the process is complicated.

The method of refining the permanent magnetic domain by laser is a method of improving the iron loss by forming grooves on the surface of the steel sheet by a Q-switch, a pulse, and a continuous wave laser. The method of refining the permanent magnet by the Q-switch or pulsed laser is to form grooves by evaporation of the irradiated material during laser irradiation. It is difficult to secure the iron loss improvement rate before the heat treatment immediately after the formation of the grooves, and only after the heat treatment, And can not process the feed speed of the steel sheet at a high speed. Sputtering and hill-up are caused by scattering of melt around grooves in the process of forming surface grooves accompanied by melting of a steel sheet by a continuous wave microfabrication method by a continuous wave laser.

The refinement of the permanent magnetic domain of the grain-oriented electrical steel sheet has a defect that the iron loss is improved but the magnetic flux density is deteriorated due to the increase of the surface energy due to the groove formation.

It is an object of the present invention to provide a directional electric steel sheet and a permanent magnetic microfabrication method having excellent magnetic properties by proposing an alloy element and a groove formation pattern which can minimize magnetic flux density deterioration caused by groove formation in the permanent magnetic microfabrication technique.

A method of manufacturing a grain-oriented electrical steel sheet according to an embodiment of the present invention includes: 2.0 to 5.0% of Si; 0.005 to 0.04% of Al; 0.01 to 0.2% of Mn; 0.005 to 0.05% of N; , S: not more than 0.01% (excluding 0%), C: not more than 0.005% (excluding 0%), P: 0.0005% to 0.045%, Co: 0.1 to 3.0%, and the balance Fe and other unavoidable impurities .

And Co in an amount of 0.2 to 1.0% by weight.

A plurality of grooves are formed on the surface of the steel sheet along the longitudinal direction of the steel sheet. The grooves are formed with a distance D in the longitudinal direction of the steel sheet, and at least one of the grooves may be formed at a multiple of the distance D.

At least one of the grooves may be formed at an interval of 2 to 4 times the interval D.

A groove set including 2 to 10 grooves having an interval D on the surface of the steel sheet is formed and the interval between the groove sets may be 2 to 4 times the interval D.

The depth of the groove may be formed to 4% to 11% of the thickness of the steel sheet.

The grooves may be formed at an angle of 0 DEG to 45 DEG with respect to the width direction of the steel sheet on the basis of the irradiation angle of 0 DEG.

The grooves are formed on the surface of the steel sheet, and the grooves may be formed to have a length of 25 to 90% of the width of the steel sheet on the basis of the irradiation angle of 0 degree.

The grooves may be formed intermittently in two to twelve in the width direction of the steel sheet.

Two grooves are intermittently formed in the width direction of the steel sheet, and each groove may be formed to have a length of 20 to 45% of the width of the steel sheet from the widthwise end of the steel sheet to the center of the steel sheet.

The depth of the groove may be formed to 4% to 11% of the thickness of the steel sheet.

The groove may be formed at an angle of 0 DEG to 45 DEG with respect to the width direction of the steel sheet.

A method of manufacturing a grain-oriented electrical steel sheet according to an embodiment of the present invention includes: 2.0 to 5.0% of Si, 0.005 to 0.04% of Al, 0.01 to 0.2% of Mn, 0.01% %, Not more than 0.01% S (excluding 0%), C: 0.02% to 0.08%, P: 0.0005% to 0.045%, Co: 0.1 to 3.0%, and the balance Fe and other unavoidable impurities Hot rolling the formed slab, and cold rolling the slab to produce a cold rolled steel sheet; A first recrystallization annealing of the cold rolled sheet; And a second recrystallization annealing step for annealing the steel sheet after the first recrystallization annealing step. After the step of producing the cold-rolled sheet, the primary recrystallization annealing step, or the secondary recrystallization annealing step, grooves are formed on the surface of the steel sheet, Further comprising the step of micronizing.

The slab may contain 0.2 to 1.0 wt% Co.

It is possible to form a plurality of grooves along the direction of the length of the steel sheet and to form the grooves with a distance D in the longitudinal direction of the steel sheet and at least one or more grooves can be formed at a multiples of the distance D have.

At least one of the grooves may be formed at an interval of 2 to 4 times the interval D.

A groove set including 2 to 10 grooves having a spacing D on the surface of the steel sheet may be formed and the interval between the groove sets may be formed to be 2 to 4 times the spacing D.

The depth of the groove can be set to 4% to 11% of the thickness of the steel sheet.

The groove can be formed at an angle of 0 DEG to 45 DEG with respect to the width direction of the steel sheet.

In the magnetic microfabrication process, a line-shaped groove is formed on the surface of the steel sheet, and the groove can be formed to have a length of 25 to 90% of the width of the steel sheet at an irradiation angle of 0 degree.

2 to 12 grooves may be intermittently formed in the width direction of the steel sheet.

Two grooves may be intermittently formed in the width direction of the steel sheet, and each groove may be formed to have a length of 20 to 45% of the width of the steel sheet from the width end of the steel sheet toward the center of the steel sheet.

The depth of the groove can be set to 4% to 11% of the thickness of the steel sheet.

The groove may be formed at an angle of 0 to 45 with the width direction of the steel plate.

According to an embodiment of the present invention, it is possible to reduce magnetic flux density deterioration due to refinement of the permanent magnet and to increase the iron loss improvement ratio.

1 is a schematic view of a directional electric steel sheet according to an embodiment of the present invention.
2 is a schematic view of a directional electric steel sheet according to another embodiment of the present invention.
3 is a schematic view of a conventional directional electric steel sheet.

The terms first, second and third, etc. are used to describe various portions, components, regions, layers and / or sections, but are not limited thereto. These terms are only used to distinguish any moiety, element, region, layer or section from another moiety, moiety, region, layer or section. Thus, a first portion, component, region, layer or section described below may be referred to as a second portion, component, region, layer or section without departing from the scope of the present invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms as used herein include plural forms as long as the phrases do not expressly express the opposite meaning thereto. Means that a particular feature, region, integer, step, operation, element and / or component is specified and that the presence or absence of other features, regions, integers, steps, operations, elements, and / It does not exclude addition.

When referring to a portion as being "on" or "on" another portion, it may be directly on or over another portion, or may involve another portion therebetween. In contrast, when referring to a part being "directly above" another part, no other part is interposed therebetween.

Unless otherwise defined, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Commonly used predefined terms are further interpreted as having a meaning consistent with the relevant technical literature and the present disclosure, and are not to be construed as ideal or very formal meanings unless defined otherwise.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

A method of manufacturing a grain-oriented electrical steel sheet according to an embodiment of the present invention includes: 2.0 to 5.0% of Si; 0.005 to 0.04% of Al; 0.01 to 0.2% of Mn; 0.005 to 0.05% of N; , S: not more than 0.01% (excluding 0%), C: not more than 0.005% (excluding 0%), P: 0.0005% to 0.045%, Co: 0.1 to 3.0%, and the balance Fe and other unavoidable impurities .

Hereinafter, each composition of the electric steel sheet will be described in detail.

Si: 2.0 to 5.0 wt%

Silicon (Si) is a basic composition of an electric steel sheet, and it plays a role of lowering the core loss by increasing the resistivity of the material. If the Si content is too small, the resistivity is reduced and the eddy current loss increases, thereby deteriorating the iron loss characteristic. In addition, phase transformation between ferrite and austenite becomes active during the decarburization annealing, and the primary recrystallization texture is severely damaged. In addition, during high-temperature annealing, phase transformation between ferrite and austenite occurs and secondary recrystallization becomes unstable, and the {110} goss texture is severely damaged.

When the Si content is too high, it is preferable to use SiO ₂ and Fe ₂ SiO ₄ The oxide layer is excessively and densely formed to retard the decarburization behavior. Further, since the nitriding behavior is delayed by the decarburization behavior delay effect due to the formation of the dense oxide layer described above, nitrides such as (Al, Si, Mn) N and AlN are not sufficiently formed and sufficient crystal grain restraining force necessary for secondary recrystallization It can not be ensured. Also, if the Si content is too high, the mechanical properties of the electrical steel sheet increase in brittleness and the toughness decreases, thereby increasing the plate breakage occurrence rate during the rolling process. As a result, the plate-to-plate weldability is lowered, and easy workability can not be ensured.

As a result, if the Si content is not controlled within the predetermined range, the formation of the secondary recrystallization becomes unstable. Thus, the magnetic properties are severely damaged and the workability is deteriorated. Therefore, Si may be limited to 2.0 to 5.0% by weight.

Al: 0.005 to 0.04 wt%

Aluminum (Al) can be obtained by forming AlN which is finely precipitated at the time of hot rolling and annealing of hot-rolled steel sheet, or forming AlN, which is present in a solid solution state in the steel by nitrogen ions introduced by ammonia gas, Mn to form (Al, Si, Mn) N and AlN type nitride. These materials act as strong grain growth inhibitors.

When the content of Al is too small, sufficient effect as an inhibitor can not be expected because the number and volume of the materials are considerably low.

When the content of Al is too large, crystal growth inhibiting ability is deteriorated by forming a coarse nitride. Therefore, the content of Al is limited to 0.005 to 0.04% by weight.

Mn: 0.01 to 0.2 wt%

Manganese (Mn) increases total resistivity by decreasing eddy current loss by increasing resistivity as Si. In addition, it reacts with S in a liquefied state to form a Mn-based sulfide, or reacts with nitrogen introduced by a nitriding treatment together with Si to form precipitates of N (Al, Si, Mn). Thus, it is an important element for suppressing the growth of the primary recrystallized grains and causing secondary recrystallization.

When the content of Mn is too small, a sufficient effect as an inhibitor can not be expected because the number and volume of the materials are low.

When the content of Mn is too large, a large amount of (Fe, Mn) and Mn oxide are formed on the surface of the steel sheet in addition to Fe ₂ SiO ₄ , which hinders formation of a base coating formed during high temperature annealing, thereby deteriorating the surface quality. In addition, in the high-temperature annealing step, phase transformation between ferrite and austenite is induced, so that the aggregate structure is seriously damaged and the magnetic properties are greatly deteriorated. Therefore, the content of Mn is limited to 0.01 to 0.2% by weight.

N: 0.005 to 0.05 wt%

Nitrogen (N) is AlN, (Al, Mn) N , (Al, Si, Mn) N, N in the embodiment Si ₃ N ₄ of the so formed a precipitate, such as the invention example the slab is controlled to less than 0.01% by weight can do. When the content of N is low, the initial grain size before cold rolling becomes coarse, so that the number of grains having a {110} < 001 > orientation in the primary re-crystallization plate is increased to reduce the size of the secondary recrystallization, . More specifically, the content of N in the slab may be 0.003% by weight or less.

A step of soaking before the second recrystallization step to be described later in the production process of an electrical steel sheet may be added, and 0.005 to 0.05% by weight of N may be contained in the finally produced electrical steel sheet. More specifically, 0.0014 to 0.05% by weight of N may be contained.

S: not more than 0.01% by weight

If sulfur (S) is contained too much, precipitates of MnS are formed in the slab to inhibit grain growth. In addition, it is difficult to control the microstructure in the subsequent process by segregation at the center of the slab during casting. In addition, since MnS is not used as a grain growth inhibitor in the present invention, it is not preferable that S is added in excess of the amount inevitably introduced to cause precipitation. Therefore, the content of S is preferably 0.01 wt% or less.

C: 0.005 wt% or less

C is an element contributing to grain refinement and improving elongation by causing phase transformation between ferrite and austenite. C is an essential element for improving the rolling property of an electric steel sheet having poor brittleness and poor rolling property. However, when remaining in the final product, the carbide formed due to the magnetic aging effect is precipitated in the product plate to deteriorate the magnetic properties, so that the content should be controlled to an appropriate level.

If the content of C in the slab is too low in the range of the Si content described above, the austenite phase transformation does not sufficiently occur and the slab and the hot rolled microstructure become non-uniform. As a result, the cold rolling property is deteriorated.

If the content of C is too large in the range of the Si content described above, sufficient decarburization can not be obtained in the decarburization annealing process unless a separate process or equipment is added. Due to this phase transformation, the secondary recrystallization texture is seriously damaged. Furthermore, when the final product is applied to an electric power machine, magnetic properties are deteriorated due to magnetic aging.

Therefore, the content of C in the slab is limited to 0.02 to 0.08% by weight.

In one embodiment of the present invention, the steel sheet is subjected to decarburization annealing in the manufacturing process, and the C content in the final electrical steel sheet produced after decarburization annealing may be 0.005 wt% or less. More specifically, it may be 0.003% by weight or less.

P: 0.0005 to 0.045 wt%

Phosphorus (P) segregates in grain boundaries and interferes with grain boundary movement, and at the same time can play an auxiliary role of suppressing grain growth. Therefore, there is an effect of improving {110} < 001 > If the content of P is too small, there is no addition effect, and if P is added too much, the brittleness increases and the rolling property deteriorates greatly. Therefore, the content of P is preferably limited to 0.0005 to 0.045 wt%.

Co: 0.1 to 3.0 wt%

Cobalt (Co) improves the magnetic flux density by increasing the magnetization of iron and decreases the total iron loss by decreasing the eddy current by increasing the resistivity. If the content of Co is too small, there is no addition effect. If too much Co is added, the phase transformation between ferrite and austenite becomes active during decarburized nitriding annealing, and the primary recrystallization texture is damaged. It happens. Therefore, the content of Co is preferably limited to 0.1 to 3.0 wt%. More specifically 0.2 to 1.0% by weight.

The directional electrical steel sheet according to an embodiment of the present invention has grooves formed on the surface of a steel sheet and minimizes the deterioration of magnetic flux density due to the formation of grooves by forming the shape pattern of the grooves irregularly in the longitudinal direction or the width direction. In the case of the conventional electric steel sheet, as shown in Fig. 3, grooves were regularly formed in the longitudinal direction and the width direction of the steel sheet. In this case, the iron loss improvement ratio is the highest, but the magnetic flux density deterioration ratio is also high.

The case where the grooves are irregularly formed in the longitudinal direction of the steel sheet is schematically shown in Fig.

1, a directional electric steel sheet according to an embodiment of the present invention includes a plurality of grooves 20 formed on the surface of a steel sheet 10 along the direction of the length of the steel sheet, D, and at least one or more of the grooves may be formed with a multiple spacing D 'of the spacing D. As described above, since the grooves are irregularly formed in the longitudinal direction of the steel sheet, the magnetic flux density and the deterioration of the iron loss due to the formation of the grooves can be minimized.

The distance D in which the plurality of grooves are formed may be 1 to 10 mm.

The spacing D 'may be greater or less than the spacing D, If the spacing D 'is greater than the spacing D, then the spacing D' may be 2 to 4 times the spacing D. The magnetic flux density degradation rate can be reduced in the above-mentioned range.

More specifically, a groove set 30 including 2 to 10 grooves having an interval D on the surface of the steel sheet is formed, and the interval D 'between the groove sets may be 2 to 4 times the interval D. 1 shows an example in which the groove set 30 is composed of four grooves 20 and the interval D 'between the groove sets is twice the interval D.

The depth of the formed groove 20 may be 4% or more of the thickness of the steel sheet in order to secure the iron loss improvement ratio. Specifically from 4% to 11%.

The grooves 20 may form an angle of 0 DEG to 45 DEG with respect to the width direction of the steel sheet. As described above, by irradiating with a slanting line with respect to the width direction of the steel sheet, the magnetic field can be weakened and the magnetic property can be improved.

The case where the grooves are irregularly formed in the width direction of the steel sheet is schematically shown in Fig.

2, the directional electric steel sheet according to the embodiment of the present invention is formed with a groove 20 on the surface of the steel sheet 10, and the grooves are formed in a range of 25 to 90 %. &Lt; / RTI &gt; Since the grooves are formed in the lengths described above, deterioration of magnetic flux density and iron loss due to the formation of grooves can be minimized.

The grooves may be formed intermittently in two to twelve in the width direction of the steel sheet. In the case where the grooves are formed intermittently as compared with the case where the grooves are formed continuously, it may be advantageous in that the half-field is weakened and the deterioration of the magnetic flux density due to the grooves is reduced. When the grooves are intermittently formed, the sum of the lengths of the respective grooves formed intermittently on the basis of the irradiation angle of 0 degree may be 25 to 90% of the width of the steel sheet.

More specifically, two grooves are formed intermittently in the width direction of the steel sheet, and each groove may be formed to have a length of 20 to 45% of the width of the steel sheet from the width end of the steel sheet toward the center of the steel sheet. In Fig. 2, two grooves are formed intermittently in the width direction of the steel sheet, and each groove is formed to have a length of 30% of the width of the steel sheet from the width end of the steel sheet toward the center of the steel sheet.

The depth of the formed groove 20 may be 4% or more of the thickness of the steel sheet in order to secure the iron loss improvement ratio. Specifically from 4% to 11%.

The grooves 20 may form an angle of 0 DEG to 45 DEG with respect to the width direction of the steel sheet. As described above, by irradiating with a slanting line with respect to the width direction of the steel sheet, the magnetic field can be weakened and the magnetic property can be improved.

A method of manufacturing a grain-oriented electrical steel sheet according to an embodiment of the present invention includes: 2.0 to 5.0% of Si, 0.005 to 0.04% of Al, 0.01 to 0.2% of Mn, 0.01% %, Not more than 0.01% S (excluding 0%), C: 0.02% to 0.08%, P: 0.0005% to 0.045%, Co: 0.1 to 3.0%, and the balance Fe and other unavoidable impurities A step (S10) of hot-rolling the formed slab and then cold-rolling the slab to produce a cold-rolled sheet; A first recrystallization annealing step (S20) of the cold-rolled sheet; And a second recrystallization annealing step (S30) of annealing the steel sheet subjected to the primary recrystallization annealing, wherein after the step of producing the cold-rolled sheet, the primary recrystallization annealing step, or the secondary recrystallization annealing step, grooves (S40) of performing a magnetic domain refinement process.

In step S10, the slab is heated, followed by hot rolling, followed by cold rolling to produce a cold rolled steel sheet. Since the composition of the slab has been described above, a duplicate description will be omitted.

The slab is heated, and hot rolled to produce a hot rolled sheet. At this time, the thickness of the hot-rolled sheet may be 2.0 to 2.8 mm. Thereafter, the hot-rolled sheet is cold-rolled to produce a cold-rolled sheet. The hot-rolled sheet may be subjected to hot-rolled sheet annealing and pickling followed by cold rolling. At this time, the thickness of the cold-rolled sheet may be 0.15 to 0.35 mm.

Next, in the step S20, the cold-rolled sheet is subjected to primary recrystallization annealing.

The first recrystallization annealing step may be a step of performing steep annealing after decarburization annealing, or simultaneously performing decarburization annealing and steep annealing. The decarburization annealing and the steep annealing temperature may be 700 to 950 캜.

Next, in step S30, the steel sheet after the primary recrystallization annealing is subjected to secondary recrystallization annealing. In the secondary recrystallization annealing, a goss grain is grown from the gos nucleus. The secondary recrystallization annealing temperature may be 1100 to 1300 ° C.

The method further includes a step (S40) of forming a groove on the surface of the steel sheet after the step (S10), the step (S20) or the step (S30) and subjecting it to micro-finishing processing.

As a magnetic domain refining method, a magnetic domain refining method by a mechanical method, a magnetic domain refining method by laser irradiation, or a magnetic refining method by chemical etching can be used. The method of refining magnetic domain of an electric steel sheet is not limited to the above- A detailed description thereof will be omitted.

Since the specific pattern shape of the groove by the magnetic domain refining process is the same as that described above, a duplicate description will be omitted.

Hereinafter, the present invention will be described in more detail with reference to examples. However, these embodiments are only for illustrating the present invention, and the present invention is not limited thereto.

Example

On the surface of the grain-oriented electrical steel sheet having the composition shown in the following Table 1, continuous wave lasers were irradiated to the entire width in the width direction to form a line-shaped groove at equal intervals of 2.5 mm.

The groove was formed by changing the pattern of the groove. In the case where the length of the groove is shorter than the width direction, two grooves are formed intermittently in the width direction, and the groove is formed from both ends of the width of the steel sheet to the center of the steel sheet. At this time, the length of the groove is the sum of the two grooves formed intermittently, and is shown in Table 2 below. When the grooves are formed at different intervals, the number of grooves in the groove set having the same gap D and the gap D 'between the groove sets are shown in Table 2 below.

The iron loss and magnetic flux density of the electric steel sheet before the groove formation, the iron loss and magnetic flux density, the iron loss improvement rate and the magnetic flux density degradation rate of the electric steel sheet after the groove formation were calculated and are shown in Table 3 below.

The magnetic flux density and the iron loss were measured using a single sheet measurement method. The magnetic flux density B8 was a magnetic flux density (Tesla) induced under a magnetic field of 800 A / m and the iron loss W17 / 50 was 1.7 Tesla at a frequency of 50 Hz. (W / kg).

division Si Al Mn N S C P Co Inventive Steel 1 3.22 0.034 0.101 0.0040 0.005 0.046 0.029 0.198 Invention river 2 3.24 0.033 0.102 0.0042 0.006 0.050 0.032 0.40 Invention steel 3 3.20 0.032 0.103 0.0044 0.006 0.053 0.033 0.61 Inventive Steel 4 3.24 0.032 0.106 0.0039 0.006 0.053 0.032 0.83 Invention steel 5 3.23 0.033 0.107 0.0039 0.006 0.052 0.032 1.03 Comparative steel 3.20 0.034 0.103 0.0040 0.006 0.053 0.032 -

division Furtherance Groove length (%) Groove spacing (D, mm) Number of grooves in a groove set (pieces) Gap between sets of grooves
(D ', mm) Inventory 1 Inventive Steel 1 100 2.5 - - Inventory 2 Invention river 2 100 2.5 - - Inventory 3 Invention steel 3 100 2.5 - - Honorable 4 Inventive Steel 4 100 2.5 - - Inventory 5 Invention steel 5 100 2.5 - - Inventory 6 Inventive Steel 1 75 2.5 - - Honorable 7 Invention river 2 75 2.5 - - Honors 8 Invention steel 3 75 2.5 - - Proposition 9 Inventive Steel 4 75 2.5 - - Inventory 10 Invention steel 5 75 2.5 - - Exhibit 11 Inventive Steel 1 50 2.5 - - Inventory 12 Invention river 2 50 2.5 - - Inventory 13 Invention steel 3 50 2.5 - - Inventory 14 Inventive Steel 4 50 2.5 - - Honorable Mention 15 Invention steel 5 50 2.5 - - Inventory 16 Inventive Steel 1 100 2.5 3 5 Inventory 17 Invention river 2 100 2.5 3 5 Inventory 18 Invention steel 3 100 2.5 3 5 Evidence 19 Inventive Steel 4 100 2.5 3 5 Inventory 20 Invention steel 5 100 2.5 3 5 Inventory 21 Inventive Steel 1 100 2.5 2 7.5 Inventory 22 Invention river 2 100 2.5 2 7.5 Inventory 23 Invention steel 3 100 2.5 2 7.5 Honors 24 Inventive Steel 4 100 2.5 2 7.5 Honors 25 Invention steel 5 100 2.5 2 7.5 Comparative Example 1 Comparative steel - - - - Comparative Example 2 Comparative steel 100 2.5 - -

division Iron loss W17 / 50
(W / kg) Magnetic flux density B8
(T) Iron loss improvement ratio
(%) Magnetic flux density degradation rate
(%) Comparative Example 1 0.84 1.92 - - Comparative Example 2 0.74 1.89 11.9 1.6 Inventory 1 0.73 1.90 13.1 1.0 Inventory 2 0.73 1.90 13.1 1.0 Inventory 3 0.72 1.90 14.3 1.0 Honorable 4 0.72 1.91 14.3 0.5 Inventory 5 0.71 1.91 15.5 0.5 Inventory 6 0.76 1.91 9.5 0.5 Honorable 7 0.75 1.91 10.7 0.5 Honors 8 0.75 1.91 10.7 0.5 Proposition 9 0.74 1.91 11.9 0.5 Inventory 10 0.74 1.92 11.9 0.0 Exhibit 11 0.79 1.92 6.0 0.0 Inventory 12 0.79 1.92 6.0 0.0 Inventory 13 0.78 1.92 7.1 0.0 Inventory 14 0.78 1.92 7.1 0.0 Honorable Mention 15 0.78 1.92 7.1 0.0 Inventory 16 0.75 1.91 10.7 0.5 Inventory 17 0.75 1.91 10.7 0.5 Inventory 18 0.75 1.92 10.7 0.0 Evidence 19 0.74 1.92 11.9 0.0 Inventory 20 0.74 1.92 11.9 0.0 Inventory 21 0.78 1.92 7.1 0.0 Inventory 22 0.78 1.92 7.1 0.0 Inventory 23 0.78 1.92 7.1 0.0 Honors 24 0.77 1.92 8.3 0.0 Honors 25 0.77 1.92 8.3 0.0

As can be seen from Tables 1 to 3, it can be seen that the magnetic flux density degradation rate can be minimized even if the electric steel sheet having the composition according to one embodiment of the present invention forms a groove. Further, by forming the grooves in various patterns, The density degradation rate can be further reduced.

It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims and their equivalents. It will be understood that the invention may be practiced. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

10: Electric steel plate 20: Groove
30: Groove set

Claims (24)

0.005% to 0.05%, S: 0.01% or less (excluding 0%), C: 0.005% to 0.04%, Si: 0.005% or less (excluding 0%), P: 0.0005% to 0.045%, Co: 0.1% to 3.0%, and the balance Fe and other unavoidable impurities. The method according to claim 1,
And 0.2 to 1.0 wt% of Co. The method according to claim 1,
Wherein a plurality of grooves are formed on a surface of the steel plate along a longitudinal direction of the steel plate, the grooves are formed with a distance D in the longitudinal direction of the steel plate, and at least one of the grooves is formed at a multi- . The method of claim 3,
Wherein at least one of the grooves is formed at an interval of 2 to 4 times the distance D. The method of claim 3,
Wherein a groove set including 2 to 10 grooves having an interval D is formed on the surface of the steel sheet, and the interval between the groove sets is 2 to 4 times the interval D. The method of claim 3,
And the depth of the groove is set to 4% to 11% of the thickness of the steel sheet. The method of claim 3,
Wherein the groove is formed at an angle of 0 DEG to 45 DEG with respect to the width direction of the steel sheet. The method according to claim 1,
Wherein the grooves are formed in a length of 25 to 90% of the width of the steel sheet at an irradiation angle of 0 degree. 9. The method of claim 8,
Wherein the grooves are formed intermittently in two to twelve grooves in the width direction of the steel sheet. 10. The method of claim 9,
The grooves are formed intermittently in the width direction of the steel sheet, and each of the grooves has a length of 20% to 45% of the width of the steel sheet from the width end of the steel sheet toward the center of the steel sheet. 9. The method of claim 8,
And the depth of the groove is set to 4% to 11% of the thickness of the steel sheet. 9. The method of claim 8,
Wherein the groove is formed at an angle of 0 DEG to 45 DEG with respect to the width direction of the steel sheet. Al: 0.005% to 0.04%, Mn: 0.01% to 0.2%, N: 0.01% or less (excluding 0%), S: 0.01% or less ), C: 0.02 to 0.08%, P: 0.0005 to 0.045%, Co: 0.1 to 3.0%, and the remainder Fe and other unavoidable impurities are heated, hot rolled, Lt; / RTI &gt;
Subjecting the cold-rolled sheet to primary recrystallization annealing; And
And secondary recrystallization annealing the steel sheet after the primary recrystallization annealing has been completed,
Further comprising the step of forming a groove on the surface of the steel sheet to perform a magnetic domain refining treatment after the step of producing the cold-rolled sheet, the primary recrystallization annealing step, or the secondary recrystallization annealing step. 14. The method of claim 13,
Wherein the slab contains 0.2 to 1.0% by weight of Co. 14. The method of claim 13,
In the magnetic domain refining step,
Forming a plurality of grooves along the direction of the length of the steel plate, forming the grooves so as to have a distance D in the longitudinal direction of the steel sheet, and forming at least one or more grooves of the grooves at a distance of a multiple of the distance D Way. 16. The method of claim 15,
And at least one of the grooves is formed at an interval of 2 to 4 times the distance D. 16. The method of claim 15,
Wherein a groove set including 2 to 10 grooves having a spacing D is formed on the surface of the steel sheet and an interval between the groove sets is formed to be 2 to 4 times the spacing D. 16. The method of claim 15,
Wherein a depth of the groove is 4% to 11% of a thickness of the steel sheet. 16. The method of claim 15,
Wherein the grooves are formed at an angle of 0 DEG to 45 DEG with respect to a width direction of the steel sheet. 14. The method of claim 13,
In the magnetic domain refining step,
Wherein the grooves are formed to have a length of 25 to 90% of the width of the steel sheet at an irradiation angle of 0 degree. 21. The method of claim 20,
Wherein the grooves are formed intermittently in two to twelve grooves in the width direction of the steel sheet. 22. The method of claim 21,
Wherein the grooves are formed intermittently in the width direction of the steel sheet and each groove is formed to a length of 20% to 45% of the width of the steel sheet from the width end of the steel sheet toward the center of the steel sheet . 21. The method of claim 20,
Wherein a depth of the groove is 4% to 11% of a thickness of the steel sheet. 21. The method of claim 20,
Wherein the grooves are formed at an angle of 0 DEG to 45 DEG with respect to a width direction of the steel sheet.

Images