JP2018087366A - Production method of grain-oriented electromagnetic steel sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably obtain excellent magnetic properties for a grain-oriented electromagnetic steel sheet produced from a slab without using an inhibitor-forming component.SOLUTION: In this method for producing a grain-oriented electromagnetic steel sheet, a steel slab is subjected to heating at 1300°C or lower and to hot rolling to obtain a hot-rolled steel sheet which is subsequently annealed to obtain a hot-rolled annealed sheet. The hot-rolled annealed sheet is subjected to one cold rolling or two or more cold rolling interposed by an intermediate annealing to obtain a cold-rolled steel sheet having a final sheet thickness. The cold-rolled steel sheet is subjected to a primary recrystallization annealing and subsequently to a secondary recrystallization annealing. A holding temperature in the hot-rolled sheet annealing is set to 1000°C or higher and 1150°C or lower. A cooling rate from the holding temperature to 900°C after holding in the hot-rolled sheet annealing is 1°C/s or more and 10°C/s or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing a grain-oriented electrical steel sheet suitable for a core material of a transformer.

  Oriented electrical steel sheet is a soft magnetic material used as a core material for transformers and generators, and has a crystal structure in which the <001> orientation, which is the easy axis of iron, is highly aligned in the rolling direction of the steel sheet. . Such a texture preferentially grows grains of the {110} <001> orientation called the Goss orientation during secondary recrystallization annealing during the production process of grain-oriented electrical steel sheets. Formed through secondary recrystallization.

  For this grain-oriented electrical steel sheet, it is a common technique to use secondary precipitates called inhibitors to recrystallize grains having Goss orientation during finish annealing. For example, a method using AlN described in Patent Document 1 and a method using MnS and MnSe described in Patent Document 2 are disclosed and industrially put into practical use. Although the method using these inhibitors requires slab heating at a high temperature exceeding 1300 ° C., it is a very useful method for stably developing secondary recrystallized grains.

  The method using these inhibitors is a useful method for stably developing secondary recrystallized grains, but in order to finely disperse the inhibitors in steel, slab heating is performed at a high temperature exceeding 1300 ° C. It was necessary to dissolve the forming component once. In addition, since it causes deterioration of magnetic properties after secondary recrystallization, precipitates and inclusions such as inhibitors are removed from the iron core by controlling the atmosphere at a high annealing temperature of 1100 ° C or higher. There was a need to do.

  On the other hand, Patent Document 3 proposes a technique for developing goth-oriented crystal grains by secondary recrystallization without containing an inhibitor-forming component. By eliminating impurities such as inhibitor forming components as much as possible, the grain boundary energy dependence of the grain boundary energy at the time of primary recrystallization becomes obvious, and Goss orientation is possible without using an inhibitor. This is a technique for secondarily recrystallizing grains having selenium, and this effect is called a texture inhibition effect. In this method, since the step of purifying the inhibitor is unnecessary, it is not necessary to increase the temperature of the purification annealing, and further, fine dispersion of the inhibitor in the steel is not necessary. It is a method that offers great advantages both in terms of cost and maintenance, such as not requiring high-temperature slab heating.

Japanese Patent Publication No.40-15644 Japanese Patent Publication No.51-13469 JP 2000-129356 JP

  However, a material that does not contain an inhibitor-forming component has revealed a problem of large magnetic variation in the coil. As a result of earnest investigation on this cause, there is no inhibitor having a function of suppressing grain growth during primary recrystallization annealing and aligning to a certain grain size in a material that does not contain an inhibitor-forming component. For this reason, it was estimated that the change in the crystal grain size of the steel sheet after the primary recrystallization was large or the grain size distribution was not uniform even if the process conditions and material components were slightly changed. Such fluctuations may also occur in the coil, which is considered to cause variations in magnetic characteristics. As described above, it is not always easy to stably achieve good magnetic properties in the method for producing a grain-oriented electrical steel sheet using a material that does not contain an inhibitor-forming component that has been proposed so far.

  This invention is made | formed in view of said situation, and it aims at obtaining the outstanding magnetic characteristic stably about the grain-oriented electrical steel sheet manufactured from the slab, without using an inhibitor formation component.

  As a result of intensive studies, the present inventors have further improved the magnetic properties and improved the magnetic properties of the inhibitorless material by further containing a segregating element and by slowly cooling it at the initial cooling stage of hot-rolled sheet annealing. It was newly found that variation can be reduced. The experiment that led to the present invention will be described below.

<Experiment>
In mass% C: 0.024%, Si: 3.42%, Mn: 0.060%, Al: 0.0018%, N: 0.0013%, S: 0.0011%, Se: 0.0010%, Sb: 0.055%, the balance being Fe and inevitable Steel slabs A and C made of impurities: 0.025%, Si: 3.40%, Mn: 0.060%, Al: 0.0020%, N: 0.0010%, S: 0.0010%, Se: 0.0010%, Sb not contained, the balance Produced a steel slab B composed of Fe and inevitable impurities by continuous casting, heated at 1230 ° C. for 70 minutes, and then finished to a thickness of 2.7 mm by hot rolling. Thereafter, hot-rolled sheet annealing in a dry nitrogen atmosphere was performed at 1075 ° C. for 30 seconds. At that time, the cooling rate up to 900 ° C after holding the temperature at 1075 ° C was variously changed. The cooling rate in the temperature range below 900 ° C was 35 ° C / s.

After that, it was finished to a thickness of 0.23 mm by cold rolling, and further subjected to primary recrystallization annealing with decarburization in a humid atmosphere at 850 ° C for 100 seconds, 50% H ₂ -50% N ₂ and dew point 50 ° C. gave. Further, an annealing separator mainly composed of MgO was applied, and secondary recrystallization annealing was performed at 1200 ° C. for 5 hours under a hydrogen atmosphere.

B ₈ (magnetic flux density when excited at 800 A / m) of the obtained sample was measured by the method described in JIS C2550. In this experiment, in order to evaluate the magnetic variation in the coil, it was evaluated at a total of 5 positions, both in the longitudinal direction of the coil, at the center, and between the both ends and the center. The minimum value was evaluated. If the difference between the two is large, it can be said that the variation is large. FIG. 1 shows the relationship between the obtained magnetic flux density and the cooling rate up to 900 ° C. in the cooling process of hot-rolled sheet annealing. From this figure, it can be seen that in the steel slab A containing Sb, the magnetic flux density is good and the variation is small when the cooling rate is in the range of 1 to 10 ° C./s.

  Thus, in the inhibitorless material, the mechanism that contains Sb and the magnetic properties become good in the region where the cooling rate is relatively slow up to 900 ° C in the cooling of hot-rolled sheet annealing and the variation is not necessarily clear. Although not, the inventors think as follows.

  Sb is known as an element that easily segregates at the grain boundaries of steel. In the case of this experiment, when annealing at 1075 ° C., it is considered that the amount of segregation is not large due to the high temperature. Subsequently, in the cooling process, when cooling to 900 ° C. at a cooling rate exceeding 10 ° C./s, it is considered that the time for segregation of Sb is small and the grain boundary segregation amount after hot-rolled sheet annealing is small. On the other hand, if it is 10 ° C./s or less, it is considered that a large amount of Sb was segregated at the grain boundaries. When Sb segregates at the grain boundaries, many deformation bands containing Goss nuclei are generated in the next cold rolling, the Goss direction sharpness in the final product is improved, magnetic properties are improved, and variation is reduced. It is considered a thing.

  Considering this, it seems that the amount of segregation increases when the cooling rate is lowered to a temperature lower than 900 ° C., and the effect of improving the magnetism is exhibited. However, even as a component composition that does not contain an inhibitor, Al, N, S, and Se are likely to inevitably contain amounts of this experimental level. Since these are trace amounts, they are dissolved at high temperatures, but when they are below 900 ° C., they appear in the steel as precipitates such as AlN, MnS, and MnSe. It is speculated that this precipitate may affect the recrystallization structure at the time of the subsequent primary recrystallization annealing and may deteriorate the magnetic properties. Conversely, if there are many Al, N, S, and Se elements, precipitates may be formed even at 900 ° C. or higher, so it is necessary to reduce these inhibitor forming components as much as possible.

Further, although Sb was contained in this experiment, the same effect was obtained even when Sn, Mo, and P having the same segregation ability were contained.
As described above, the present inventors have improved the magnetic properties of the inhibitorless material by further containing the element having the segregation ability (segregation element) and cooling it slowly in the initial stage of hot-rolled sheet annealing. And succeeded in reducing variation.

The present invention is based on the above-described novel findings, and the gist of the present invention is as follows.
1. % By mass
C: 0.002% to 0.100%,
Si: 2.00% to 8.00% and
Mn: 0.005% or more and 1.000% or less,
Sn: 0.010% or more and 0.400% or less; Sb: 0.010% or more and 0.400% or less; Mo: 0.010% or more and 0.200% or less; and P: 0.010% or more and 0.200% or less. ,
Al: less than 0.0100%, N: less than 0.0050%, S: less than 0.0050% and Se: less than 0.0050%, the remainder has a component composition of Fe and inevitable impurities, the slab is heated at 1300 ° C or less Hot-rolled steel sheet by hot rolling from
The hot-rolled steel sheet is subjected to hot-rolled sheet annealing to form a hot-rolled annealed sheet,
The hot-rolled annealed sheet is subjected to two or more cold-rolling sandwiching one cold-rolling or intermediate annealing to obtain a cold-rolled steel sheet having a final sheet thickness,
Subjecting the cold-rolled steel sheet to primary recrystallization annealing,
A method for producing a grain-oriented electrical steel sheet that performs secondary recrystallization annealing on the cold-rolled steel sheet after the primary recrystallization annealing,
Directional electromagneticity in which the holding temperature in the hot-rolled sheet annealing is 1000 ° C. or higher and 1150 ° C. or lower, and the cooling rate from the holding temperature to 900 ° C. is 1 ° C./s or higher and 10 ° C./s or lower in cooling after holding. A method of manufacturing a steel sheet.

2. 2. The method for producing a grain-oriented electrical steel sheet according to 1, wherein a cooling rate from the holding temperature to 900 ° C. is 1 ° C./s or more and 5 ° C./s or less.

3. 3. The method for producing a grain-oriented electrical steel sheet according to 1 or 2 above, wherein a cooling rate from 900 ° C. to 350 ° C. in the cooling is 20 ° C./s or more.

4). The component composition further includes:
% By mass
Cr: 0.01% to 0.50%,
Cu: 0.01% or more and 0.50% or less,
Ni: 0.01% or more and 0.50% or less,
Bi: 0.005% to 0.500%,
B: 0.0002% to 0.0025% and
Nb: The manufacturing method of the grain-oriented electrical steel sheet according to any one of 1 to 3 above, containing one or more selected from 0.0010% to 0.0100%.

  ADVANTAGE OF THE INVENTION According to this invention, the outstanding magnetic characteristic can be stably acquired about the grain-oriented electrical steel sheet manufactured from the slab without using an inhibitor formation component.

It is a graph showing the relationship between the cooling rate and the magnetic flux density B ₈ of up to 900 ° C. in the cooling step of the hot-rolled sheet annealing.

[Ingredient composition]
Hereinafter, a grain-oriented electrical steel sheet and a manufacturing method thereof according to an embodiment of the present invention will be described. First, the reasons for limiting the component composition of steel will be described. In the present specification, “%” representing the content of each component element means “% by mass” unless otherwise specified.

C: 0.002% to 0.100%
If C exceeds 0.100%, it becomes difficult to reduce it to 0.005% or less where no magnetic aging occurs after decarburization annealing, so it is limited to 0.100% or less. On the other hand, if it is less than 0.002%, the grain boundary strengthening effect due to C is lost, and cracks occur in the slab, causing defects that hinder operability. Therefore, C is 0.002% or more and 0.100% or less. Preferably, it is 0.010% or more and 0.050% or less.

Si: 2.00% to 8.00%
Si is an element necessary for increasing the specific resistance of steel and improving iron loss. However, if it is less than 2.00%, there is no effect, and if it exceeds 8.00%, the workability of the steel deteriorates and rolling is difficult. Therefore, it should be 2.00% or more and 8.00% or less. Preferably, it is 2.50% or more and 4.50% or less.

Mn: 0.005% to 1.000%
Mn is an element necessary for improving hot workability, but if it is less than 0.005%, there is no effect, and if it exceeds 1.000%, the magnetic flux density of the product plate decreases, so 0.005% or more and 1.000% or less And Preferably, it is 0.040% or more and 0.200% or less.

Sn: 0.010% or more and 0.400% or less, Sb: 0.010% or more and 0.400% or less, Mo: 0.010% or more and 0.200% or less, and P: 0.010% or more and 0.200% or less In order to improve the quality, at least one of segregating elements Sn: 0.010% to 0.400%, Sb: 0.010% to 0.400%, Mo: 0.010% to 0.200%, P: 0.010% to 0.200% It is essential to contain. In each case, if the amount is less than the lower limit value, there is no effect of improving the magnetism, and if the amount is more than the upper limit value, the steel becomes brittle and the risk of breakage or the like occurring during the production increases. Preferably, Sn: 0.020% to 0.100%, Sb: 0.020% to 0.100%, Mo: 0.020% to 0.070%, P: 0.012% to 0.100%.

  The content of Al, N, S and Se as inhibitor forming components is reduced as much as possible and is limited to Al: less than 0.0100%, N: less than 0.0050%, S: less than 0.0050% and Se: less than 0.0050%. Preferably, Al is less than 0.0070%, N is less than 0.0040%, S is less than 0.0030%, and Se is less than 0.0030%.

  The basic components in the present invention are as described above, and the balance is Fe and inevitable impurities. Examples of such unavoidable impurities include impurities inevitably mixed from raw materials, production facilities, and the like. Further, in the present invention, other elements described below can be appropriately contained.

  In the present invention, for the purpose of improving magnetic properties, Cr: 0.01% or more and 0.50% or less, Cu: 0.01% or more and 0.50% or less, Ni: 0.01% or more and 0.50% or less, Bi: 0.005% or more and 0.500% Hereinafter, one or more selected from B: 0.0002% to 0.0025% and Nb: 0.0010% to 0.0100% can be appropriately contained. When the added amount of each component composition is less than the lower limit amount, there is no effect of improving the magnetic properties, and when the upper limit amount is exceeded, the development of secondary recrystallized grains is suppressed and the magnetic properties are deteriorated.

Next, the manufacturing method of the grain-oriented electrical steel sheet of this invention is demonstrated.
A slab is produced from the molten steel, which has been adjusted for a predetermined component, by a normal ingot-making method or a continuous casting method. A thin slab having a thickness of 100 mm or less may be produced by a direct casting method, but in this case, the following heating and hot rolling steps are not performed. Since optional addition components are difficult to add in the middle of the process, they are added at the molten steel stage.

[heating]
The slab is heated and hot-rolled by a normal method, but this component system does not require high-temperature annealing to dissolve the inhibitor, so it is heated at a low temperature of 1300 ° C or lower. Thereby, cost can be reduced. Preferably it is 1250 degrees C or less. The soaking time is preferably 5 minutes or more in order to heat the slab to the inside, and is preferably 120 minutes or less from the viewpoint of cost.

[Hot rolling]
After the heating, hot rolling is performed. The hot rolling temperature is desirably a finish rolling start temperature of 900 ° C. or higher and an end temperature of 750 ° C. or higher for improving characteristics. However, the end temperature is preferably 1000 ° C. or lower because the hot rolling scale characteristics change.

[Hot rolled sheet annealing]
Hot-rolled sheet annealing is performed after the hot rolling. In order to dissolve Al, S, Se, and N, which may be inevitably included, the holding temperature in hot-rolled sheet annealing must be 1000 ° C. or higher. However, if the holding temperature of hot-rolled sheet annealing exceeds 1150 ° C., the desired primary recrystallized structure cannot be obtained because the grain size after hot-rolled sheet annealing becomes too coarse. Accordingly, the holding temperature for hot-rolled sheet annealing is set to 1150 ° C. or lower. Preferably they are 1025 degreeC or more and 1100 degrees C or less. The holding time is preferably 5 seconds or more and 300 seconds or less for the same reason.

  For the reasons described above, it is essential that the cooling after the hot-rolled sheet annealing is performed at a cooling rate from the holding temperature to 900 ° C. from 1 ° C./s to 10 ° C./s. Preferably, it is 1 ° C./s or more and 5 ° C./s or less. Further, for cooling from 900 ° C. to 350 ° C., it is more preferable that rapid cooling is performed at 20 ° C./s or more. These cooling rates are averaged over the section. The cooling method is not limited, but it is desirable to perform steam mist cooling up to 900 ° C., and quenching by spraying water onto the steel sheet.

[Cold rolling]
After the hot-rolled sheet annealing, the cold-rolled steel sheet having a final sheet thickness is obtained by performing at least one cold rolling with intermediate annealing as necessary. The intermediate annealing temperature is preferably from 950 ° C to 1200 ° C. When the temperature is lower than 950 ° C., solid solution of Al, S, Se, and N, which can be included unavoidably, does not proceed. On the other hand, if the temperature exceeds 1200 ° C., the desired primary recrystallized structure cannot be obtained because the grain size after annealing becomes too coarse. The intermediate annealing time is preferably about 10 seconds or more and 300 seconds or less for the same reason. In the final cold rolling, the temperature of the cold rolling is increased to 100 to 300 ° C, and the aging treatment in the range of 100 to 300 ° C is performed once or a plurality of times during the cold rolling. This is effective for improving the magnetic properties by changing the crystal texture.

[Primary recrystallization annealing]
Primary recrystallization annealing is performed after the cold rolling. The primary recrystallization annealing may also serve as decarburization annealing. From the viewpoint of decarburization, the primary recrystallization annealing is effective from 800 ° C. to 900 ° C. Further, from the viewpoint of decarburization, it is desirable that the atmosphere is a humid atmosphere. The annealing time is preferably about 20 seconds to 300 seconds. However, this does not apply when the content of C: 0.005% or less is not required.

[Application of annealing separator]
An annealing separator is applied to the steel sheet after the primary recrystallization annealing as necessary. Here, when forming a forsterite film with an emphasis on iron loss, an annealing separation agent mainly composed of MgO is applied, and then secondary recrystallization annealing is performed by also performing purification annealing. The next recrystallized structure can be developed and a forsterite film can be formed. When the forsterite film is not required with emphasis on the punching processability, the annealing separator is not applied, or even when it is applied, MgO that forms the forsterite film is not used, but silica, alumina or the like is used. When these annealing separators are applied, it is effective to perform electrostatic application or the like that does not bring in moisture. A heat resistant inorganic material sheet (silica, alumina, mica) may be used.

[Secondary recrystallization annealing]
Secondary recrystallization annealing is performed after the primary recrystallization annealing or after application of the annealing separator. Secondary recrystallization annealing may also serve as purification annealing. The secondary recrystallization annealing that also serves as the purification annealing is desirably performed at 800 ° C. or higher for the purpose of secondary recrystallization. In order to complete the secondary recrystallization, it is desirable to hold at a temperature of 800 ° C. or higher for 20 hours or longer. If the forsterite film is not formed with emphasis on punchability, the secondary recrystallization should be completed, so the holding temperature is preferably 850 to 950 ° C, and annealing may be completed by holding in this temperature range. Is possible. When emphasizing iron loss or forming a forsterite film to reduce transformer noise, it is desirable to raise the temperature to about 1200 ° C.

[Flatening annealing]
After the secondary recrystallization annealing, planarization annealing is performed as necessary. When an annealing separator is applied, washing, brushing, and pickling are performed to remove the attached annealing separator. After that, it is effective to reduce the iron loss by performing flattening annealing to correct the shape. The flattening annealing temperature is preferably about 750 to 1000 ° C. from the viewpoint of shape correction.

[Insulating coating]
In the case where the steel plates are laminated and used, in order to improve iron loss, it is effective to apply an insulating coating to the steel plate surface before or after the flattening annealing. As the coating, a coating capable of imparting tension to the steel sheet to reduce iron loss is desirable. It is preferable to employ a tension coating application method using a binder, or a method in which an inorganic substance is vapor-deposited on a steel sheet surface layer by physical vapor deposition or chemical vapor deposition. This is because these methods are excellent in coating adhesion and provide a significant iron loss reduction effect.

[Magnetic domain subdivision processing]
After the flattening annealing, it is effective to perform a magnetic domain fragmentation process to reduce iron loss. The processing methods include, for example, a method of making a groove in the final product plate as commonly practiced, a method of introducing thermal strain and impact strain linearly by a laser or an electron beam, and a final finished plate thickness. For example, a method of previously grooved intermediate products such as cold rolled sheets.
Other manufacturing conditions may follow the general manufacturing method of a grain-oriented electrical steel sheet.

Example 1
Contains C: 0.009%, Si: 3.11%, Mn: 0.040%, Al: 0.0020%, N: 0.0009%, S: 0.0015%, Se: 0.0020%, P: 0.150% by mass%, the balance being Fe and inevitable A steel slab composed of mechanical impurities was produced by continuous casting, subjected to slab heating at 1230 ° C. for 80 minutes, and then finished to a thickness of 2.0 mm by hot rolling. Thereafter, hot-rolled sheet annealing in a dry nitrogen atmosphere was performed at 1000 ° C. for 20 seconds. At that time, the cooling rate from 900 ° C. to 900 ° C. after maintaining the temperature at 1000 ° C. and the cooling rate from 900 ° C. to 350 ° C. were variously changed. After that, it is cold rolled to a thickness of 0.18mm, and further subjected to primary recrystallization annealing with decarburization in a humid atmosphere at 800 ° C for 70 seconds, 52% H ₂ -48% N ₂ and dew point 60 ° C. gave.

Thereafter, an annealing separator mainly composed of MgO was applied, and secondary recrystallization annealing was performed at 1225 ° C. for 10 hours under a hydrogen atmosphere. B ₈ (magnetic flux density when excited at 800 A / m) of the obtained sample was measured by the method described in JIS C2550. In this experiment, in order to evaluate the magnetic variation in the coil, it was evaluated at a total of 5 positions, both in the longitudinal direction of the coil, at the center, and between the both ends and the center. The minimum value was evaluated. If the difference between the two is large, it can be said that the variation is large. Table 1 shows the relationship between the obtained magnetic flux density B ₈ and the cooling rate in the hot-rolled sheet annealing step. As is apparent from Table 1, it can be seen that good and small magnetic characteristics can be obtained under the cooling rate conditions within the scope of the present invention.

(Example 2)
A steel slab composed of Fe and unavoidable impurities is produced by continuous casting, including the components listed in Table 2, and after slab heating is performed at 1150 ° C for 35 minutes, the thickness is 2.3 mm by hot rolling. Finished. Thereafter, hot-rolled sheet annealing in a dry nitrogen atmosphere was performed at 1125 ° C. for 20 seconds. At that time, the cooling rate from 900 ° C. after maintaining the temperature at 1125 ° C. was 5 ° C./s, and the cooling rate from 900 ° C. to 350 ° C. was 40 ° C./s. After that, it was finished to a thickness of 0.23 mm by cold rolling, and further subjected to primary recrystallization annealing with decarburization in a humid atmosphere of 840 ° C for 150 seconds, 55% H ₂ -45% N ₂ , dew point 60 ° C. gave.

Thereafter, an annealing separator mainly composed of MgO was applied, and secondary recrystallization annealing was performed at 1200 ° C. for 10 hours in a hydrogen atmosphere. B ₈ (magnetic flux density when excited at 800 A / m) of the obtained sample was measured by the method described in JIS C2550. In this experiment, in order to evaluate the magnetic variation in the coil, it was evaluated at a total of 5 positions, both in the longitudinal direction of the coil, at the center, and between the both ends and the center. The minimum value was evaluated. If the difference between the two is large, it can be said that the variation is large. Table 2 also shows the relationship between the obtained magnetic flux density B ₈ and the cooling rate in the hot-rolled sheet annealing process. As is apparent from Table 2, it can be seen that good and small magnetic characteristics can be obtained under the cooling rate conditions within the scope of the present invention.

Claims (4)

% By mass
C: 0.002% to 0.100%,
Si: 2.00% to 8.00% and
Mn: 0.005% or more and 1.000% or less,
Sn: 0.010% or more and 0.400% or less; Sb: 0.010% or more and 0.400% or less; Mo: 0.010% or more and 0.200% or less; and P: 0.010% or more and 0.200% or less. ,
Al: less than 0.0100%, N: less than 0.0050%, S: less than 0.0050% and Se: less than 0.0050%, the remainder has a component composition of Fe and inevitable impurities, the slab is heated at 1300 ° C or less Hot-rolled steel sheet by hot rolling from
The hot-rolled steel sheet is subjected to hot-rolled sheet annealing to form a hot-rolled annealed sheet,
The hot-rolled annealed sheet is subjected to two or more cold-rolling sandwiching one cold-rolling or intermediate annealing to obtain a cold-rolled steel sheet having a final sheet thickness,
Subjecting the cold-rolled steel sheet to primary recrystallization annealing,
A method for producing a grain-oriented electrical steel sheet that performs secondary recrystallization annealing on the cold-rolled steel sheet after the primary recrystallization annealing,
Directional electromagneticity in which the holding temperature in the hot-rolled sheet annealing is 1000 ° C. or higher and 1150 ° C. or lower, and the cooling rate from the holding temperature to 900 ° C. is 1 ° C./s or higher and 10 ° C./s or lower in cooling after holding. A method of manufacturing a steel sheet.   The manufacturing method of the grain-oriented electrical steel sheet according to claim 1, wherein a cooling rate from the holding temperature to 900 ° C is 1 ° C / s or more and 5 ° C / s or less.   The method for producing a grain-oriented electrical steel sheet according to claim 1 or 2, wherein a cooling rate from 900 ° C to 350 ° C in the cooling is 20 ° C / s or more. The component composition further includes:
% By mass
Cr: 0.01% to 0.50%,
Cu: 0.01% or more and 0.50% or less,
Ni: 0.01% or more and 0.50% or less,
Bi: 0.005% to 0.500%,
B: 0.0002% to 0.0025% and
The method for producing a grain-oriented electrical steel sheet according to any one of claims 1 to 3, comprising one or more selected from Nb: 0.0010% or more and 0.0100% or less.

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