KR102428115B1 - Method for manufacturing orientied electrical steel sheet - Google Patents

Abstract

The method of manufacturing a grain-oriented electrical steel sheet according to an embodiment of the present invention comprises the steps of reheating a slab comprising 1.0% to 4.5% Si by weight%, and the remainder Fe and other unavoidable impurities; manufacturing a hot-rolled sheet by hot rolling the reheated slab; first cold rolling the hot-rolled sheet; intermediate annealing of the first cold-rolled cold-rolled sheet; Secondary cold rolling of the intermediate annealed cold-rolled sheet; and final annealing the secondary cold-rolled cold-rolled sheet in a non-oxidizing atmosphere. Volume fraction of grains having an orientation within 15° from the {110}<001> orientation with respect to the volume fraction (V _rot ) of grains having an orientation within 15° from the {001}<110> orientation in the intermediate annealed cold-rolled sheet (V _goss ) The ratio (V _goss /V _rot ) is 3 or more, the temperature increase rate in the final annealing step may be 5 to 100 ℃ / hr.

Description

Manufacturing method of grain-oriented electrical steel sheet {METHOD FOR MANUFACTURING ORIENTIED ELECTRICAL STEEL SHEET}

It relates to a method of manufacturing a grain-oriented electrical steel sheet. Specifically, it relates to a method for manufacturing a grain-oriented electrical steel sheet without using a precipitate grain growth inhibitor such as AlN or MnS.

The grain-oriented electrical steel sheet has excellent magnetic properties in the rolling direction by forming a {110}<001> texture (Goss texture) throughout the steel sheet by secondary recrystallization using a precipitate grain growth inhibitor such as AlN and MnS. It is a soft magnetic material used as the iron core of a stationary machine that requires excellent one-way magnetic properties such as transformers. Magnetic properties include magnetic flux density and iron loss, and the higher the degree of orientation in the <001> direction with respect to the rolling direction, the better the magnetic flux density. In addition, as for the iron loss, the lower the steel sheet thickness and the amount of impurities, the higher the magnetic flux density and the specific resistance.

In general, grain-oriented electrical steel sheets are manufactured through hot rolling, hot-rolled sheet annealing, cold rolling, recrystallization annealing, and final annealing processes. Secondary recrystallization refers to a phenomenon in which Goss grains grow abnormally after losing inhibitory power during final annealing in a state where grain growth is suppressed by precipitates, etc. In general, precipitates such as AlN and MnS are used as grain growth inhibitors.

In order to stably form secondary recrystallization in a grain-oriented electrical steel sheet, precipitates of an appropriate size must be uniformly precipitated in the steel sheet, and complicated process variables must be controlled to control these precipitates. In addition, if precipitates remain in the final product on which secondary recrystallization has been completed, it is necessary to remove the precipitates after completion of secondary recrystallization, as it interferes with the movement of the magnetic domain and increases iron loss. To this end, it is subjected to a purification annealing process for a long time at a high temperature of about 1200 ° C. At this time, AlN precipitates are separated from Al and N, and Al reacts with oxygen on the surface to form Al ₂ O ₃ and is removed, and MnS precipitates are removed from Mn and S is separated and S diffuses to the surface, reacts with hydrogen, and is discharged as H ₂ S and removed. As such, a grain-oriented regular steel sheet manufacturing technology that does not use a grain growth inhibitor such as precipitates is needed to solve the problems associated with the complicated manufacturing process for controlling precipitates and to secure stable magnetism.

As a grain-oriented electrical steel sheet manufacturing technology that does not use a grain growth inhibitor, there is a method of growing Goss grains using surface energy. The surface energy varies according to the orientation and is highest in the order of {110}, {001}, and {111} in vacuum, and the order changes depending on the atmosphere. By performing final annealing in a non-oxidizing atmosphere, Goss grains with the {110} plane with the lowest surface energy grow while encroaching on other grains with higher surface energy. However, since grain growth by surface energy is applied only to grains existing on the surface of the steel sheet, it is known that the thickness of the steel sheet must be thin. However, there is a problem in that productivity is greatly reduced due to a heavy load on the cold rolling process due to the thin steel sheet thickness.

An embodiment of the present invention does not use precipitates such as AlN, MnS, etc. as a grain growth inhibitor and controls the texture through appropriate process conditions to form a Goss texture without performing annealing for a long time at high temperature to have excellent magnetic properties. To provide a grain-oriented electrical steel sheet and a method for manufacturing the same.

The method of manufacturing a grain-oriented electrical steel sheet according to an embodiment of the present invention comprises the steps of reheating a slab comprising 1.0% to 4.5% Si by weight%, and the remainder Fe and other unavoidable impurities; manufacturing a hot-rolled sheet by hot rolling the reheated slab; first cold rolling the hot-rolled sheet; intermediate annealing of the first cold-rolled cold-rolled sheet; Secondary cold rolling of the intermediate annealed cold-rolled sheet; and final annealing the secondary cold-rolled cold-rolled sheet in a non-oxidizing atmosphere. Volume fraction of grains having an orientation within 15° from the {110}<001> orientation with respect to the volume fraction (V _rot ) of grains having an orientation within 15° from the {001}<110> orientation in the intermediate annealed cold-rolled sheet (V _goss ) The ratio (V _goss /V _rot ) is 3 or more, the temperature increase rate in the final annealing step may be 5 to 100 ℃ / hr.

The method of manufacturing a grain-oriented electrical steel sheet according to another embodiment of the present invention comprises the steps of reheating a slab comprising 1.0% to 4.5% Si as a weight%, and the remainder Fe and other unavoidable impurities; manufacturing a hot-rolled sheet by hot rolling the reheated slab; first cold rolling the hot-rolled sheet; intermediate annealing of the first cold-rolled cold-rolled sheet; Secondary cold rolling of the intermediate annealed cold-rolled sheet; and final annealing the secondary cold-rolled cold-rolled sheet in a non-oxidizing atmosphere. Volume fraction of grains having an orientation within 15° from the {110}<001> orientation with respect to the volume fraction (V _rot ) of grains having an orientation within 15° from the {001}<110> orientation in the intermediate annealed cold-rolled sheet (V _goss ) The ratio (V _goss /V _rot ) is 4 or more, the temperature increase rate in the final annealing step may be 5 to 300 ℃ / hr.

In the step of reheating the slab, the reheating temperature may be 1000 °C to 1350 °C.

After the step of preparing the hot-rolled sheet, the method may further include annealing the hot-rolled sheet at a temperature of 900°C to 1200°C.

The reduction ratio in the first cold rolling step may be 20 to 65%, and the reduction ratio in the second cold rolling step may be 20 to 60%.

In the final annealing step, the non-oxidizing atmosphere may be a vacuum or a hydrogen atmosphere.

The final steel sheet thickness may be 0.2 mm to 0.5 mm.

The slab may further include Al, Mn, S or N in an amount of 0.005 wt% or less (excluding 0 wt%).

The method of manufacturing a grain-oriented electrical steel sheet according to another embodiment of the present invention comprises the steps of reheating the slab comprising 1.0% to 4.5% of Si as a weight%, and the remainder Fe and other unavoidable impurities; hot rolling the reheated slab; processing the hot-rolled hot-rolled sheet to have only a shear deformation structure; cold rolling the processed hot-rolled sheet; and final annealing the cold-rolled cold-rolled sheet in a non-oxidizing atmosphere. In the hot-rolled sheet processed to have only the shear strain structure, the volume fraction (V _rot ) of the grains having an orientation within 15° from the {001}<110> orientation has an orientation within 15° from the {110}<001> orientation. The ratio of the volume fraction (V _goss ) of the crystal grains (V _goss /V _rot ) is 3 or more, and the temperature increase rate in the final annealing step may be 5 to 100 °C / hr.

In the step of reheating the slab, the reheating temperature may be 1000 °C to 1350 °C.

The step of processing to have only the shear deformation structure may be asymmetric rolling in which the size of the upper and lower rolling rolls or the upper and lower rolling roll speeds are different.

In the cold rolling step, the reduction ratio may be 40 to 80%.

In the final annealing step, the non-oxidizing atmosphere may be a vacuum or hydrogen atmosphere.

The final steel sheet thickness may be 0.2 mm to 0.5 mm.

The slab may further include Al, Mn, S or N in an amount of 0.005 wt% or less (excluding 0 wt%).

The method of manufacturing a grain-oriented electrical steel sheet according to an embodiment of the present invention uses surface energy in the final annealing in a non-oxidizing atmosphere and the deformation and recrystallization behavior of Goss grains in the control of texture and low cold rolling reduction ratio without grain growth inhibitor. A grain-oriented electrical steel sheet having excellent magnetism can be manufactured by growing Goss grains on the entire steel sheet.

In addition, since the method of manufacturing a grain-oriented electrical steel sheet according to an embodiment of the present invention is manufactured without a grain growth inhibitor, a complicated process for removing the grain growth inhibitor is unnecessary, thereby simplifying the process and reducing the cost.

In addition, since the method of manufacturing a grain-oriented electrical steel sheet according to an embodiment of the present invention is manufactured without a grain growth inhibitor, complicated process variables for controlling the precipitates are removed, thereby ensuring stable iron loss and magnetic flux density.

1 is an orientation distribution (ODF) analysis result of the hot-rolled sheet of Example 1 after primary cold rolling.
FIG. 2 is an orientation distribution function (ODF) analysis result after the first cold rolling of the hot-rolled sheet of Example 2. FIG.

The terms first, second, third, etc. are used to describe, but are not limited to, various parts, components, regions, layers and/or sections. These terms are used only 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.

The terminology used herein is for the purpose of referring to specific embodiments only, and is not intended to limit the invention. As used herein, the singular forms also include the plural forms unless the phrases clearly indicate the opposite. As used herein, the meaning of “comprising” specifies a particular characteristic, region, integer, step, operation, element and/or component, and the presence or absence of another characteristic, region, integer, step, operation, element, and/or component. It does not exclude additions.

When a part is referred to as being “on” or “on” another part, it may be directly on or on the other part, or the other part may be involved in between. In contrast, when a part refers to being "directly above" another part, the other part is not interposed therebetween.

Although not defined otherwise, all terms including technical 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. Commonly used terms defined in the dictionary are additionally interpreted as having a meaning consistent with the related technical literature and the presently disclosed content, and unless defined, they are not interpreted in an ideal or very formal meaning.

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

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

In one embodiment of the present invention, the Rot. By controlling the ratio (V _goss /V _rot ) of the volume fraction (V _goss ) of the Goss grains to the volume fraction of the cube grains, it is possible to manufacture a grain-oriented electrical steel sheet having excellent magnetism without using a grain growth inhibitor. In one embodiment of the present invention, Rot. Cube grains are defined as grains having an orientation within 15° from the {001}<110> orientation, and Goss grains are defined as grains having an orientation within 15° from the 110}<001> orientation. More specifically, Rot. Cube grains may be defined as grains having an orientation within 5° from the {001}<110> orientation, and Goss grains may be defined as grains having an orientation within 5° from the 110}<001> orientation.

The method of manufacturing a grain-oriented electrical steel sheet according to an embodiment of the present invention comprises the steps of reheating a slab comprising 1.0% to 4.5% Si by weight%, and the remainder Fe and other unavoidable impurities; manufacturing a hot-rolled sheet by hot rolling the reheated slab; first cold rolling the hot-rolled sheet; intermediate annealing of the first cold-rolled cold-rolled sheet; Secondary cold rolling of the intermediate annealed cold-rolled sheet; and final annealing the secondary cold-rolled cold-rolled sheet in a non-oxidizing atmosphere. Volume fraction of grains having an orientation within 15° from the {110}<001> orientation with respect to the volume fraction (V _rot ) of grains having an orientation within 15° from the {001}<110> orientation in the intermediate annealed cold-rolled sheet (V _goss ) The ratio (V _goss /V _rot ) is 3 or more, the temperature increase rate in the final annealing step may be 5 to 100 ℃ / hr.

The method of manufacturing a grain-oriented electrical steel sheet according to another embodiment of the present invention is the same as the above-described manufacturing method, but the volume fraction of grains having an orientation within 15° from the {001}<110> orientation in the intermediate annealed cold-rolled sheet (V _rot ) When the ratio (V _goss /V _rot ) of the volume fraction (V _goss ) of the crystal grains having an orientation within 15° from the {110}<001> orientation for (V rot ) is 4 or more, the temperature increase rate in the final annealing step may be 5 to 300°C/hr.

Hereinafter, each step will be described in detail.

First, the slab comprising 1.0 wt% to 4.5 wt% of Si, and the remainder Fe and other unavoidable impurities, is reheated.

Silicon (Si) serves to increase the resistivity of the electrical steel sheet and reduce the magnetic anisotropy to lower the iron loss. If the content is less than 1.0% by weight, the specific resistance increase and magnetic anisotropy reduction effect is small, so iron loss is inferior. If the content is more than 4.5% by weight, brittleness increases and cold rolling becomes difficult. limit

In an embodiment of the present invention, since precipitates such as AlN and MnS are not used as grain growth inhibitors, Al, N, Mn, S, etc. in the slab are treated as impurities, and it is preferable to include as little as possible. However, it does not exclude the case where it is unavoidably included in the manufacturing process, and specifically, it may further include Al, Mn, S or N in an amount of 0.005 wt % or less.

In the reheating step, the reheating temperature may be 1000°C to 1350°C. When reheating in the above temperature range, in the final annealing step to be described later, the growth rate of Goss grains may be improved.

Next, a hot-rolled sheet is prepared by hot rolling the reheated slab. The thickness of the hot-rolled sheet may be 1 mm to 3 mm. After the hot-rolled sheet is manufactured by hot rolling, it may further include the step of annealing the hot-rolled sheet. When the step of annealing the hot-rolled sheet is further included, Rot. It is possible to further remove band structures such as cube crystal grains. In the step of annealing the hot-rolled sheet, the annealing temperature may be 900°C to 1200°C.

Next, the hot-rolled sheet is first cold-rolled. At this time, it is possible to control the texture before the final cold rolling by setting the reduction ratio to be 80% or less. More specifically, the reduction ratio may be 20 to 65%.

Next, the primary cold-rolled cold-rolled sheet is intermediate annealed. Through intermediate annealing, the texture before final cold rolling can be controlled. During intermediate annealing, the annealing temperature may be 700°C to 1000°C. At this time, Rot. The ratio of the volume fraction (V _goss ) of the Goss grains to the volume fraction of the cube grains (V _goss /V _rot ) may be 3 or more. More specifically, Rot. The ratio of the volume fraction (V _goss ) of the Goss grains to the volume fraction of the cube grains (V _goss /V _rot ) may be 4 or more. By controlling the texture in this way, it is possible to strongly form Goss grains in the final annealing step to be described later.

Next, the intermediate annealed cold-rolled sheet is subjected to secondary cold rolling. At this time, the reduction ratio is set to be 70% or less, thereby improving the growth rate of Goss grains during final annealing. More specifically, the reduction ratio may be 20 to 60%.

Next, the secondary cold-rolled cold-rolled sheet is final annealed in a non-oxidizing atmosphere. At this time, Goss grains are strongly formed. By controlling the texture before final cold rolling, Rot. When the formation of cube grains is suppressed, Goss grains and {111}<112> grains, which are the main orientations having {110} and {111} faces, are mainly formed during final annealing, so that the {110} and {111} faces are high. The driving force of grain growth increases due to the difference in surface energy, which increases the growth rate of Goss grains, making it possible to grow Goss grains even on thick steel sheets. In addition, the growth rate of Goss grains is improved by using the deformation and recrystallization behavior of Goss grains at low cold rolling reduction. Goss and Rot with the lowest Taylor factors. Cube orientation has deformation and recrystallization behavior different from normal orientation at low cold rolling reduction. A low Taylor factor means low stored energy due to deformation, and Goss and Rot. Since Cube grains have a lower stored energy compared to grains with other orientations around them, they grow rapidly by encroaching on the surrounding grains with high energy during final annealing. Therefore, the fraction of Goss grains before final cold rolling is high and Rot. The fraction of cube grains forms a low recrystallized structure so that Goss grains can grow during final annealing.

Specifically, the non-oxidizing atmosphere means a vacuum or hydrogen atmosphere. The final annealing may be performed at a temperature increase rate of 5 to 100°C/hr up to 1200°C. Rot. When the ratio (V _goss /V _rot ) of the volume fraction (V _goss ) of the Goss crystal grains to the volume fraction of the cube crystal grains is 4 or more, it is also possible to make the temperature increase rate faster, specifically, the temperature increase rate to 1200 ° C is 5 to It can be 300°C/hr.

The method of manufacturing a grain-oriented electrical steel sheet according to another embodiment of the present invention comprises the steps of reheating the slab comprising 1.0% to 4.5% of Si as a weight%, and the remainder Fe and other unavoidable impurities; hot rolling the reheated slab; processing the hot-rolled hot-rolled sheet to have only a shear deformation structure; cold rolling the processed hot-rolled sheet; and final annealing the cold-rolled cold-rolled sheet in a non-oxidizing atmosphere. In the hot-rolled sheet processed to have only the shear strain structure, the volume fraction (V _rot ) of the grains having an orientation within 15° from the {001}<110> orientation has an orientation within 15° from the {110}<001> orientation. The ratio of the volume fraction (V _goss ) of the crystal grains (V _goss /V _rot ) is 3 or more, and the temperature increase rate in the final annealing step may be 5 to 100 °C / hr.

A description that overlaps with the above-described embodiment will be omitted.

In another embodiment of the present invention, it includes the step of processing the hot-rolled hot-rolled sheet to have only a shear-deformed structure, which may be specifically asymmetric rolling in which the size of the upper and lower rolling rolls or the upper and lower rolling roll speeds are different. Through this, Rot. The ratio (V _goss /V _rot ) of the volume fraction (V _goss ) of the Goss grains to the volume fraction of the cube grains can be controlled to 3 or more.

Unlike the above-described embodiment, when the texture of the hot-rolled sheet is controlled, cold rolling may be performed once, and in this case, the reduction ratio may be 40 to 80%.

In one embodiment of the present invention, the final steel sheet thickness may be 0.2mm to 0.5mm, and the magnetic flux density B10 has excellent magnetism of 1.88T or more.

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

Example One

After reheating the slab containing 3.0% of Si by weight and the remainder Fe and other unavoidable impurities to a temperature of 1050 ° C. It was carried out at 80%, intermediate annealing at a temperature of 800°C to form a recrystallized structure, and then cold rolling was performed at a reduction ratio of 30, 40, and 50% for growth of Goss grains. The final annealing was carried out in vacuum at a temperature increase rate of 15 or 240 °C/hr to a temperature of 1200 °C. Table 1 shows the results for the process conditions. In the table, Goss and Rot. The cube fraction was obtained through EBSD analysis, and the tolerance angle was 15°. The results of ODF analysis are shown in FIG. 1 .

1st cold rolling reduction rate
(%) intermediate annealing After Goss/Rot. Cube rain 2nd cold rolling reduction rate
(%) final
steel plate thickness
( mm ) final Annealing
temperature rise rate
(℃/ hr ) magnetic flux density
B10
( Tesla ) division 65 3.0 50 0.35 15 1.89 invention example 65 40 0.42 15 1.89 65 30 0.49 15 1.88 65 0 0.70 15 1.55 comparative example 65 30 0.49 240 1.85 70 0.5 0 0.60 15 1.53 70 30 0.42 15 1.71 80 0.7 0 0.40 15 1.54 80 30 0.28 15 1.69 80 30 0.28 240 1.65

As shown in Table 1, the Rot. When the ratio of the fraction of Goss grains to the fraction of cube grains was 3.0 or higher, a grain-oriented electrical steel sheet having a magnetic flux density B10 of 1.88T or higher could be manufactured.

If the reduction ratio in the primary cold rolling was 70% or more, the fraction of Goss grains decreased rapidly after the intermediate annealing, so that B10 was less than 1.88T regardless of the temperature increase rate of the secondary rolling and final annealing. If the reduction ratio in the first cold rolling is 65% and the final annealing temperature increase rate is 15℃/hr, when the final annealing is performed without the second cold rolling, the B10 is 1.55T, and the Goss grains did not grow, but 30, 40, 50 %, B10 became 1.88T or more when secondary cold rolling was performed. Through this, it can be confirmed that the growth of Goss grains is promoted through secondary rolling with a low reduction ratio. On the other hand, when the temperature increase rate was increased to 240℃/hr, B10 was slightly inferior to 1.85T, which was related to the fraction of Goss grains and Rot. It is analyzed that when the ratio of the fraction of cube grains is increased, the growth of Goss grains is promoted and the magnetic flux density is improved.

Example 2

After reheating the slab containing 3.0% Si by weight and the remainder Fe and other unavoidable impurities to a temperature of 1050℃, hot rolling is performed to manufacture a 1.5mm thick hot-rolled sheet, and the texture is obtained by static recrystallization and grain growth. After performing hot-rolled sheet annealing at 1050℃ to weaken the , was subjected to cold rolling to 50%. The final annealing was carried out in vacuum at a temperature increase rate of 15, 240 °C/hr to a temperature of 1200 °C. The results for the process conditions are shown in Table 2. In the table, Goss and Rot. The cube fraction was obtained through EBSD analysis, and the tolerance angle was 15°. The results of ODF analysis are shown in FIG. 2 .

1st cold rolling reduction rate
(%) intermediate annealing Who G o ss/ Rot . Cube rain 2nd cold rolling reduction rate
(%) final
steel plate thickness
( mm ) final Annealing
temperature rise rate
(℃/ hr ) magnetic flux density
B10
( Tesla ) division 65 4.4 30 0.37 15 1.90 invention example 65 50 0.26 15 1.92 65 50 0.26 240 1.89 65 0 0.53 15 1.80 comparative example 80 0.9 30 0.21 240 1.63

As shown in Table 2, after the first intermediate annealing, the Rot. The ratio of the fraction of Goss grains to the fraction of Cube grains increased compared to Table 1. This is the Rot. This is because there was no band organization in the direction of Cube. When the reduction ratio was 80% in the primary cold rolling, the magnetic flux density was inferior, but when the reduction ratio was 65%, the magnetic flux density B10 was 1.88T or more regardless of the temperature increase rate and the reduction ratio in the secondary cold rolling. In particular, even when the final annealing temperature increase rate was 240℃/hr, B10 was as high as 1.89T, and Goss was formed on the entire steel sheet even at a fast temperature increase rate compared to the general growth of Goss grains only at a slow temperature increase rate of about 15℃/hr. A collective organization was formed.

Example 3

After reheating the slab containing 3.0% Si by weight and the remainder Fe and other unavoidable impurities to a temperature of 1100℃, hot rolling is performed, and processing is performed to have only a shear deformation structure through asymmetric rolling with different upper and lower rolling roll speeds. A hot-rolled sheet having a thickness of 1 mm was manufactured and cold-rolled at a reduction ratio of 50, 60, 70, and 80%. The final annealing was performed in a vacuum, a non-oxidizing atmosphere, at a temperature increase rate of 15°C/hr to a temperature of 1200°C. Table 3 shows the results for the process conditions. In the table, Goss and Rot. The cube fraction was obtained through EBSD analysis, and the tolerance angle was 15°.

hot rolled sheet Goss / Rot . Cube rain cold rolled
reduction rate final
steel plate thickness
( mm ) final annealing
temperature rise rate
(℃/ hr ) magnetic flux density
B10
( Tesla ) division 15 50% 0.50 15 1.93 invention example 60% 0.40 15 1.96 70% 0.30 15 1.97 80% 0.20 15 1.94

As shown in Table 3, the Rot. The ratio of the fraction of Goss grains to the fraction of Cube grains is very high compared to Examples 1 and 2. Therefore, they all have a high magnetic flux density irrespective of a cold rolling reduction rate.

The present invention is not limited to the embodiments, but can be manufactured in various different forms, and those of ordinary skill in the art to which the present invention pertains can use other specific forms without changing the technical spirit or essential features of the present invention. It will be appreciated that this may be practiced. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

Claims (15)

Reheating the slab comprising 1.0% to 4.5% Si as a weight%, and the remainder Fe and other unavoidable impurities;
manufacturing a hot-rolled sheet by hot rolling the reheated slab;
first cold rolling the hot-rolled sheet;
intermediate annealing of the first cold-rolled cold-rolled sheet;
Secondary cold rolling of the intermediate annealed cold-rolled sheet; and
Final annealing of the secondary cold-rolled cold-rolled sheet in a non-oxidizing atmosphere
including,
The volume of grains having an orientation within 15° from the {110}<001> orientation with respect to the volume fraction (V _rot ) of the grains having an orientation within 15° from the {001}<110> orientation in the intermediate annealed cold-rolled sheet The ratio (V _goss /V _rot ) of the fraction (V _goss ) is 3 or more,
A method of manufacturing a grain-oriented electrical steel sheet having a temperature increase rate of 5 to 100° C./hr in the final annealing step. Reheating the slab comprising 1.0% to 4.5% Si as a weight%, and the remainder Fe and other unavoidable impurities;
manufacturing a hot-rolled sheet by hot rolling the reheated slab;
first cold rolling the hot-rolled sheet;
intermediate annealing of the first cold-rolled cold-rolled sheet;
Secondary cold rolling of the intermediate annealed cold-rolled sheet; and
Final annealing of the secondary cold-rolled cold-rolled sheet in a non-oxidizing atmosphere
including,
The volume of grains having an orientation within 15° from the {110}<001> orientation with respect to the volume fraction (V _rot ) of the grains having an orientation within 15° from the {001}<110> orientation in the intermediate annealed cold-rolled sheet The ratio (V _goss /V _rot ) of the fraction (V _goss ) is 4 or more,
A method of manufacturing a grain-oriented electrical steel sheet having a temperature increase rate of 5 to 300° C./hr in the final annealing step. 3. The method of claim 1 or 2,
The reheating temperature in the step of reheating the slab is a method of manufacturing a grain-oriented electrical steel sheet from 1000 ℃ to 1350 ℃. 3. The method of claim 1 or 2,
After the step of manufacturing the hot-rolled sheet, the method of manufacturing a grain-oriented electrical steel sheet further comprising the step of annealing the hot-rolled sheet at a temperature of 900 ℃ to 1200 ℃. 3. The method of claim 1 or 2,
A method of manufacturing a grain-oriented electrical steel sheet having a reduction ratio of 20 to 65% in the first cold rolling step, and 20 to 60% in the secondary cold rolling step. 3. The method of claim 1 or 2,
In the final annealing step, the non-oxidizing atmosphere is a vacuum or hydrogen atmosphere, a method of manufacturing a grain-oriented electrical steel sheet. 3. The method of claim 1 or 2,
A method for producing a grain-oriented electrical steel sheet having a final steel sheet thickness of 0.2 mm to 0.5 mm. 3. The method of claim 1 or 2,
The slab is a method of manufacturing a grain-oriented electrical steel sheet further comprising Al, Mn, S or N in an amount of 0.005% by weight or less (excluding 0% by weight). Reheating the slab comprising 1.0% to 4.5% Si as a weight%, and the remainder Fe and other unavoidable impurities;
hot rolling the reheated slab;
processing the hot-rolled hot-rolled sheet to have only a shear deformation structure;
cold rolling the processed hot-rolled sheet;
Final annealing of the cold-rolled cold-rolled sheet in a non-oxidizing atmosphere
including,
In the hot-rolled sheet processed to have only the shear strain structure, the volume fraction (V _rot ) of the grains having an orientation within 15° from the {001}<110> orientation has an orientation within 15° from the {110}<001> orientation. The ratio (V _goss /V _rot ) of the volume fraction (V _goss ) of the grains is 3 or more,
A method of manufacturing a grain-oriented electrical steel sheet having a temperature increase rate of 5 to 100° C./hr in the final annealing step. 10. The method of claim 9,
The reheating temperature in the step of reheating the slab is a method of manufacturing a grain-oriented electrical steel sheet from 1000 ℃ to 1350 ℃. 10. The method of claim 9,
The step of processing to have only the shear strain structure is asymmetrical rolling in which the size of the upper and lower rolling rolls or the upper and lower rolling roll speeds are different. 10. The method of claim 9,
The cold rolling step is a method of manufacturing a grain-oriented electrical steel sheet having a reduction ratio of 40 to 80%. 10. The method of claim 9,
In the final annealing step, the non-oxidizing atmosphere is a vacuum or hydrogen atmosphere, a method of manufacturing a grain-oriented electrical steel sheet. 10. The method of claim 9,
A method for producing a grain-oriented electrical steel sheet having a final steel sheet thickness of 0.2 mm to 0.5 mm. 10. The method of claim 9,
The slab is a method of manufacturing a grain-oriented electrical steel sheet further comprising Al, Mn, S or N in an amount of 0.005% by weight or less (excluding 0% by weight).

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