JP2013253320A - Slurry coating device and slurry coating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve an yield in manufacturing of a grain-oriented electromagnetic steel sheet by suppressing generation of wrinkle-like shape defects along a longitudinal direction of the steel sheet, that tends to be generated after flattening annealing in manufacturing of the steel sheet.SOLUTION: A slurry coating device 20 includes: a slurry supply nozzle 3 for supplying annealing separation agent slurry 4 to a traveling band-like body 1; a pair of squeeze rolls 2 for swinging the band-like body 1 in a direction roughly parallel to a surface and roughly perpendicular to a traveling direction, while holding and pressurizing the band-like body 1 and applying the supplied annealing separation agent slurry 4 to the surface of the band-like body 1; and a band-like body conveying roll 5 for swinging the band-like body 1 in the direction roughly parallel to the surface of the band-like body 1 and roughly perpendicular to the traveling direction, while making it travel. In the slurry coating device 20, by the squeeze rolls 2 and the band-like body conveying roll 5, while swinging the traveling band-like body 1 in a triangular wave shape, a sine wave shape or a rectangular wave shape along the direction perpendicular to the traveling direction, the annealing separation agent slurry 4 is discharged to the band-like body 1.

Description

  The present invention relates to a slurry coating apparatus and a slurry coating method for coating a slurry of an annealing separator for preventing seizure when performing high temperature annealing on a coil wound with a grain-oriented electrical steel sheet to the grain-oriented electrical steel sheet. .

  Conventionally, grain-oriented electrical steel sheets are mainly used as iron core materials for transformers, generators, and other electrical devices. Therefore, the grain-oriented electrical steel sheet is required to have a good surface coating in addition to good magnetic properties (iron loss).

The surface coating of the steel plate is made of a ceramic coating called a forsterite coating. When forming a forsterite film, first, a material that has been rolled to a predetermined thickness by cold rolling is used as a raw material, and an oxide film (subscale) containing silicon oxide (SiO ₂ ) as a base material for this material. ). Next, after applying magnesium oxide (MgO) on the oxide film, the steel sheet is wound into a coil shape. And in a final annealing process, it heat-processes at 1000 degreeC or more with respect to a coil-shaped grain-oriented electrical steel sheet. As a result, SiO ₂ and MgO react on the surface of the steel sheet to form a forsterite film (Mg ₂ SiO ₄ film). In addition, since MgO applied to the surface of the steel sheet also serves as an adhesion preventing agent for preventing adhesion between coil layers in the final annealing process, it is also referred to as an annealing separator. After the finish annealing step, the steel sheet is flattened (planarized) to correct the shape of the steel sheet to obtain a product.

  In general, an annealing separator such as MgO is suspended in water to form a slurry. Then, on the exit side of the continuous annealing furnace in the decarburization annealing step, the supply nozzle and the squeeze roll apply this slurry so as to have a predetermined film thickness on both the upper surface and the lower surface of the strip. At this time, a liquid pool is often formed on the entrance side of the squeeze roll on the upper surface side of the belt-like body. Subsequently, after the annealing separator is dried in a drying furnace, the strip is wound to obtain a coil.

  Conventionally, these supply nozzles and squeeze rolls, as described in Patent Document 1, supply the slurry to the belt-like body by the supply nozzle, and then adjust the film thickness of the slurry by squeeze rolls such as a rough application roll and an application roll. Adjustable arrangement. Depending on the required accuracy of the film thickness and the installation space, only one of the coarse application roll and the application roll is installed, or a nozzle is further provided between the coarse application roll and the application roll. It may be configured to supply slurry.

  Moreover, as described in Patent Document 2, there is a case where the slurry is supplied to the band by the supply nozzle after the band has passed through all the application rolls. In this case, a plurality of nozzles for supplying the slurry are installed at intervals of several hundred mm in the width direction which is a direction perpendicular to the traveling direction of the belt-like body.

JP 2004-57971 A JP-A-62-67118

  By the way, after the flattening annealing in the manufacturing process of the steel sheet described above, a strip-like shape parallel to the longitudinal direction may occur in the belt-shaped body that is the steel sheet. In the belt-like body, the portion where such a shape defect has occurred does not become a product and must be discarded. For this reason, the occurrence of shape defects leads to a decrease in yield in the production of steel sheets. However, the details of the mechanism by which this saddle-shaped defect occurs are not clear, and the development of a technique for suppressing the occurrence of this saddle-shaped defect has been demanded.

  The present invention has been made in view of the above, and the object thereof is to suppress the occurrence of saddle-like shape defects along the longitudinal direction of a steel sheet, which are likely to occur after flattening annealing in the manufacture of a steel sheet. An object of the present invention is to provide a slurry coating apparatus and a slurry coating method capable of improving the yield in the production of steel plates.

  In order to solve the above-described problems and achieve the above-described object, the slurry coating apparatus according to the present invention swings the strip in a direction substantially parallel to the surface of the traveling strip and substantially perpendicular to the traveling direction of the strip. The belt-shaped body swinging means configured to be movable, the slurry discharging means configured to be able to supply slurry to the band-shaped body, and the supplied slurry is applied to the surface of the band-shaped body by pressing while holding the band-shaped body A pair of applicator means configured to be possible.

  In the slurry application apparatus according to the present invention, in the above invention, the slurry is pressed onto the surface of the band-like body by holding the band-like body and pressing it against the pair of application means on the downstream side along the traveling direction of the band-like body. A second pair of coating means configured to be coated is provided.

  The slurry coating apparatus according to the present invention is the second slurry configured to supply the slurry to the traveling strip on the downstream side along the traveling direction of the strip with respect to the pair of coating means in the above invention. Discharging means is provided.

  A slurry application method according to the present invention includes a slurry supply step of supplying a slurry while swinging a traveling strip in a direction substantially parallel to the surface of the strip and substantially perpendicular to the traveling direction of the strip, And a slurry application step of applying the slurry to the surface of the belt-like body by holding and pressing the belt-like body supplied.

  In the slurry application method according to the present invention, in the above invention, after the slurry application step, a second slurry application step of applying the slurry to the surface of the belt-like body by holding and pressing the belt-like body supplied with the slurry is further performed. It is characterized by including.

  The slurry application method according to the present invention is characterized in that, in the above invention, the method further includes a second slurry supply step for supplying the slurry to the traveling strip after the slurry application step.

  The slurry coating apparatus and the slurry coating method according to the present invention are characterized in that, in the above invention, the temporal change of the swing amount in the swing is a rectangular wave shape, a sine wave shape, or a triangular wave shape.

  The slurry coating apparatus and the slurry coating method according to the present invention are characterized in that, in the above invention, the oscillation frequency of the strip is set based on a turn pitch of a coil formed by winding the strip.

  The slurry coating apparatus and the slurry coating method according to the present invention are characterized in that, in the above invention, the oscillation frequency of the strip is set based on an even multiple of a turn pitch of a coil formed by winding the strip. To do.

  According to the slurry coating apparatus and the slurry coating method according to the present invention, it is possible to suppress the occurrence of saddle-like shape defects along the longitudinal direction of the steel sheet, which are likely to occur after flattening annealing in the production of the steel sheet, and manufacture of the steel sheet. It becomes possible to improve the yield in.

FIG. 1 is a configuration diagram illustrating a slurry coating apparatus according to an embodiment of the present invention. FIG. 2 is a conceptual diagram showing a conventional slurry coating apparatus and a film thickness distribution of the annealing separator slurry on the surface of the strip. FIG. 3A is a cross-sectional perspective view of a coil of a belt-like body to which a conventional annealing separator slurry is applied. FIG. 3B is a partially enlarged cross-sectional view of a dotted line encircled portion in FIG. 3A. FIG. 4A is a graph showing an example of swing control for a band according to an embodiment of the present invention. FIG. 4B is a graph illustrating an example of swing control for the band according to an embodiment of the present invention. FIG. 4C is a graph showing an example of swing control for the band according to an embodiment of the present invention. FIG. 5 is a conceptual diagram showing a slurry coating apparatus according to an embodiment of the present invention and the film thickness distribution of the annealing separator slurry on the surface of the band when the band is controlled to swing sinusoidally. is there. FIG. 6A is a conceptual diagram showing a slurry coating apparatus according to an embodiment of the present invention and a film thickness distribution of the annealing separator slurry on the surface of the band when the band-shaped rocking control is performed on the band. is there. FIG. 6B is a partially enlarged cross-sectional view of a state in which a strip-like body coated with an annealing separator slurry according to an embodiment of the present invention is coiled. FIG. 7A is a configuration diagram illustrating a first modification of the slurry application device according to the embodiment of the present invention. FIG. 7B is a configuration diagram illustrating a second modification of the slurry application device according to the embodiment of the present invention. FIG. 7C is a configuration diagram illustrating a third modification of the slurry application device according to the embodiment of the present invention.

  Embodiments of the present invention will be described below with reference to the drawings. In all the drawings of the following embodiments, the same or corresponding parts are denoted by the same reference numerals. Further, the present invention is not limited to the embodiments described below.

  First, in order to facilitate the understanding of the contents of the present invention, a diligent study conducted by the present inventors for a slurry coating apparatus and a slurry coating method will be described. First, a slurry coating apparatus according to this embodiment will be described. FIG. 1 is a configuration diagram showing a slurry application device for applying an annealing separator slurry.

  As shown in FIG. 1, the slurry application device 20 according to this embodiment includes a squeeze roll 2, a slurry supply nozzle 3, and a belt-like body transport roll 5. The slurry supply nozzle 3 is a slurry discharge means having a plurality of discharge ports for applying the annealing separator slurry 4 to the strip 1 that is a grain-oriented electrical steel sheet. The squeeze roll 2 is a pair of application means that sandwich the strip 1 in the thickness direction and squeeze the annealing separator slurry 4 applied on the strip 1 to a predetermined thickness. Further, the belt-shaped body transporting roll 5 is a belt-shaped body transporting unit configured to be able to transport the belt-shaped body 1 by rotating around the central axis of a circle in the column while being configured, for example, in a cylindrical shape. . In addition, although mentioned later for details, the squeeze roll 2 and the strip | belt-shaped object conveyance roll 5 in this one Embodiment are the directions orthogonal to the direction (running direction) which sends out the strip | belt-shaped body 1 in parallel with the surface, ie, a strip | belt-shaped body. 1 is a belt-like body swinging means configured to be swingable along the width direction of 1.

  In the application of the annealing separator slurry 4 using the slurry application device 20 configured as described above, first, the slurry supply nozzle 3 applies the annealing separator slurry 4 to the strip 1. Subsequently, the annealing separator slurry 4 with the squeeze roll 2 applied to the surface of the strip 1 is squeezed to a predetermined film thickness. After that, the strip 1 is subjected to various processes such as a finish annealing process (secondary recrystallization annealing process), a coating process, and a flattening annealing process, and finally becomes a product of an electromagnetic steel sheet.

  Here, when the conventional slurry application | coating apparatus was used, the present inventors examined the saddle-like shape defect formed on the surface of the strip 1 after the flattening annealing step. As a result, the present inventors have found that a certain correlation is recognized between the generation position along the width direction of the strip 1 and the installation position along the width direction of the slurry supply nozzle 3 with respect to the shape defect. I found out. Then, the inventors pay attention to the fact that the film thickness of the annealing separator slurry 4 has a non-uniform distribution along the width direction of the strip 1, and this film thickness distribution affects the shape defect. I came to remember.

  FIG. 2 is a block diagram of the conventional slurry coating apparatus 100 and an annealing separator slurry along the width direction of the strip 1 after the annealing separator slurry 4 on the strip 1 is narrowed to a predetermined film thickness. 4 is a graph showing a film thickness distribution of No. 4;

  As shown in FIG. 2, when the slurry supply nozzle 3 supplies the annealing separator slurry 4 to the surface of the strip 1, the film thickness of the annealing separator slurry 4 is close to each discharge port of the slurry supply nozzle 3. It is considered to be larger and smaller at a distant position. Therefore, in the conventional slurry coating apparatus 100, the film thickness distribution along the width direction of the strip 1 and the film thickness distribution along the longitudinal direction of the annealing separator slurry 4 are controlled. Thereby, the thickness difference of the film thickness of the annealing separator slurry 4 on the surface of the strip 1 is within a predetermined range. However, even if the thickness difference of the film thickness of the annealing separator slurry 4 falls within a predetermined range as described above, the occurrence of the above-described bowl-shaped shape defect cannot be avoided.

  According to the knowledge of the present inventors, it is inevitable that a slight film thickness distribution of the annealing separator slurry 4 is generated on the surface of the strip 1 due to the installation position of the discharge port of the slurry supply nozzle 3. That is, uneven application of the annealing separator slurry 4 composed of a crest portion having a relatively large film thickness and a trough portion having a relatively small film thickness is caused by the position of the discharge port of the slurry supply nozzle 3, which is an inevitable phenomenon. It is believed that there is.

  Therefore, the present inventors conducted further earnest studies, and further examined the influence of uneven application of the annealing separator slurry 4 on the occurrence of shape defects.

  And when the present inventors wind up the strip | belt-shaped body 1 which apply | coated the annealing separator slurry 4 and make it a coil, the peak part and trough part of the annealing separator slurry 4 on the strip | belt-shaped body 1 will be the width | variety of the strip | belt-shaped body 1. We paid attention to the fact that it always exists at the same position in the direction. Here, FIG. 3A is a cross-sectional perspective view along the width direction of the strip 1 in a state where the strip 1 coated with the annealing separator slurry 4 is wound to form a coil 10, and FIG. It is an expanded sectional view of the dotted line surrounding part.

  That is, as shown in FIG. 3A, when the strip 1 is wound into a coil shape to form a hollow cylindrical coil 10, the peak of the annealing separator slurry 4 on the surface of the strip 1 is formed as shown in FIG. 3B. The coils 10 are sequentially laminated in the radial direction of the circle in the cross section along the longitudinal direction of the strip 1, so-called build-up occurs, and the annealing separator slurry 4 protrudes (inside the dotted line in FIG. 3B). And it is thought that the buildup in the peak part of the annealing separator slurry 4 on the surface of the strip 1 causes the shape defect of the strip 1 during the finish annealing process. In addition, the position of the streak pattern due to the coating unevenness that is visually recognized after supplying the annealing separator slurry 4 to the surface of the strip 1 does not necessarily match the position of the shape defect formed on the surface of the strip 1.

  From the above, the present inventors have a non-uniform film thickness rather than completely suppressing the occurrence of a non-uniform film thickness distribution of the annealing separator slurry 4 along the width direction of the strip 1 that is unavoidable. Recalling that the occurrence of shape defects can be suppressed if the distribution of the film thickness is made as gentle as possible, or the build-up when the strip 1 is made into a coil can be suppressed on the premise of the occurrence of the distribution.

  Therefore, as shown in FIG. 1, the slurry applying apparatus 20 according to the embodiment of the present invention is configured to squeeze the strip 1 with respect to the slurry supply nozzle 3 by the squeeze roll 2 and the strip transport roll 5. A configuration is employed in which the surface is swung in the direction parallel to the surface and perpendicular to the traveling direction, that is, along the width direction of the strip 1.

  4A, FIG. 4B, and FIG. 4C each show an example of the change over time of the swing amount in the swing control for the strip 1 when the strip 1 is swung by the squeeze roll 2 and the strip transport roll 5. It is a graph. FIG. 5 shows an annealing separator along the width direction of the strip 1 when the swing control is performed on the strip 1 based on the configuration diagram of the slurry application device 20 and the graph shown in FIG. 4A. 4 is a graph showing a film thickness distribution of slurry 4.

  The squeeze roll 2 and the belt-like body transporting roll 5 swing the belt-like body 1 in a sine wave shape as shown in FIG. 4A or in a triangular wave shape as shown in FIG. 4B along the width direction. . Thereby, as shown in the graph of the film thickness distribution of the annealing separator slurry 4 in FIG. 5, the film thickness distribution of the annealing separator slurry 4 along the width direction of the band 1 is the same as that of the band 1 shown in FIG. Compared to the case where the annealing separator slurry 4 is discharged in a state of being conveyed without being swung (as indicated by the dotted line in the graph of FIG. 5), the slurry becomes gentler. Here, it is desirable that the swinging width of the strip 1 shown in FIG. 5 is about ½ of the interval between adjacent discharge ports of the plurality of discharge ports of the slurry supply nozzle 3. Thereby, the supply of the annealing separator slurry 4 can be averaged with respect to the width direction of the strip 1 between the plurality of discharge ports of the slurry supply nozzle 3.

  4A and 4B, the pitch T as the oscillation period of the strip 1 is 1 to 150 seconds, preferably 2 to 120 seconds. As a result, as shown in FIG. 5, the annealing separator slurry 4 is gently applied to the surface of the strip 1 as compared to the non-uniformity of the film thickness distribution of the annealing separator slurry 4 shown in FIG. The part and the mountain part are gently formed. Therefore, the thickness difference in the film thickness distribution is relaxed and becomes gentle, and the occurrence of shape defects on the surface of the strip 1 can be prevented. In practice, when triangular wave-like swing control is performed on the belt-like body 1, due to restrictions of the swing mechanism, as shown in FIG. Or a trapezoidal wave when stopped at this end for a finite period of time, these oscillations are also included in the triangular wave oscillation.

  FIG. 6A is a block diagram of the slurry application apparatus and two layers of the annealing separator slurry 4 on the surface of the band 1 when the swing control is performed on the band 1 based on the graph shown in FIG. 4C. It is a graph which shows film thickness distribution. 6B corresponds to FIG. 3B in the case where the surface of the strip 1 is coated with the annealing separator slurry 4 as shown in FIG. 6A and then wound into a coil to form the coil 10 shown in FIG. 3A. 3 is a partially enlarged cross-sectional view showing a state of a laminated structure of a coil 10. FIG.

  As shown in FIG. 4C, when the band 1 swings in a rectangular wave shape along the width direction of the band 1, the band 1 is formed into a coil 10 as shown in the graph of the film thickness distribution in FIG. 6A. In addition, the crests and troughs of the annealing separator slurry 4 overlap between the two layers in the laminated strip 1. Here, it is desirable that the swinging width of the belt-like body 1 is about ½ of the interval between adjacent discharge ports among the plurality of discharge ports of the slurry supply nozzle 3.

  Also, the pitch T, which is the oscillation period of the strip 1 shown in FIG. 4C, is preferably 1 to 150 seconds, and preferably 2 to 120 seconds. This is because if the pitch T in the case of controlling the time variation of the oscillation amount to be a rectangular wave is too shorter than 1 second, the non-uniformity of the film thickness distribution of the annealing separator slurry 4 as shown in FIG. If it is longer than 2 seconds, the amount of deviation for each turn when the strip 1 is used as the coil 10 becomes small, and the peaks and valleys of the annealing separator slurry 4 do not overlap properly between the two layers. This is because the build-up shown in FIG. Actually, when swing control is performed on the band 1 in a rectangular wave shape, the moving speed of the band 1 is finite and it is difficult to instantaneously move the band 1 along the width direction. However, such a swing control is also included in the rectangular wave swing.

  As a result, as shown in FIG. 6B, the peaks and valleys in the film thickness distribution of the annealing separator slurry 4 are sequentially along the radial direction of the circle of the section along the longitudinal direction of the strip 1 in the coil 10. Since the layers are alternately stacked, the build-up described above can be prevented. Therefore, it is possible to suppress the occurrence of a shape defect in the band 1.

(Modification)
Next, the configuration of the slurry coating apparatus in the separating agent coating process to which the apparatus configuration according to the above-described embodiment can be applied will be described. 7A, FIG. 7B, and FIG. 7C are configuration diagrams of a slurry application device showing a first modification, a second modification, and a third modification, respectively.

(First modification)
As shown in FIG. 7A, the slurry application device 21 according to the first modification includes a pair of rough application rolls 2a, a pair of backup rolls 2b, a pair of application rolls 2c, and a pair of nozzles 3a before the rough application roll. The pair of pre-rough application roll nozzles 3 a is a pair of slurry discharge means for discharging the annealing separator slurry 4 to both surfaces of the strip 1. The pair of rough coating rolls 2a is a pair of coating means for roughly coating the both surfaces of the strip 1 with the annealing separator slurry 4 supplied by the nozzle 3a before the rough coating roll. The pair of application rolls 2 c is a second pair of application means that squeeze the coarsely coated annealing separator slurry 4 supported by a pair of backup rolls 2 b provided on both sides of the strip 1. In the slurry application device 21 according to the first modification, the rough application roll 2a and the application roll 2c, and the backup roll 2b as necessary, together with the belt-like body 1 as the belt-like body swinging means. 1 is configured to be swingable along a width direction (vertical direction in FIG. 7A).

(Second modification)
Further, as shown in FIG. 7B, the slurry application device 22 according to the second modification is the same as that in the slurry application device 21 according to the first modification, as slurry discharge means along the traveling direction of the strip 1. A pre-coating roll nozzle 3b as a second slurry discharge means is provided on one surface side of the strip 1 on the downstream side of the pre-rough coating roll nozzle 3a and the upstream side of the pair of coating rolls 2c. In this slurry application device 22 as well, the belt-shaped body 1 is a belt-shaped body conveying roll (not shown), a rough coating roll 2a and a coating roll 2c, and a backup roll 2b as necessary. At the same time, it is configured to be swingable along the width direction of the strip 1 (in FIG. 7B, the direction perpendicular to the paper surface).

(Third Modification)
Further, as shown in FIG. 7C, the slurry application device 23 according to the third modification is the same as the slurry application device 21 according to the first modification, and further includes a pair of application rolls 2 c along the traveling direction of the strip 1. , A post-rolling-roll nozzle 3c as a second slurry discharge means is provided on the other surface side of the strip 1 on the downstream side. Also in this slurry coating device 23, the belt-shaped body 1 is a strip-shaped body conveying roll (not shown), the rough coating roll 2a and the coating roll 2c, and, if necessary, the backup roll 2b as the belt-shaped body rocking means. At the same time, it is configured to be swingable along the width direction of the strip 1 (in FIG. 7C, the direction perpendicular to the paper surface).

  Next, an example based on the second modified example according to the embodiment of the present invention described above and a comparative example based on the prior art will be described. The present invention is not limited to these examples.

(Examples 1 to 15 and Comparative Example 1)
In Examples 1 to 15 and Comparative Example 1, first, a cold rolled sheet of grain-oriented electrical steel sheet containing 3.4% by weight of silicon (Si) having a final sheet thickness of 0.3 mm is used as the band 1. It was. And after performing decarburization annealing with respect to this strip | belt body 1, the annealing separation agent slurry 4 was apply | coated to the strip | belt body 1 using the slurry application | coating apparatus 22 by a 2nd modification. Specifically, the coating amount of the annealing separator slurry 4 per one side is set to 7.0 g / m ² , and the surface of the belt 1 is oxidized on both sides by the nozzle 3a before the rough coating roll and the nozzle 3b before the coating roll. Apply magnesium (MgO). Then, after winding the strip | belt-shaped body 1 into the coil 10, a final annealing process is performed with respect to this coil 10 on 1200 degreeC temperature conditions. After the finish annealing step, the shape of the band 1 is corrected in a flattening annealing furnace under the condition where the temperature is 850 ° C. And the presence or absence of the shape defect along a longitudinal direction was test | inspected visually with respect to the strip | belt-shaped body 1 by which shape correction was carried out.

  In these Examples 1 to 15, the swing control of the strip 1 when the annealing separator slurry 4 is applied to the surface of the strip 1 is performed as follows.

  That is, in Examples 1 to 5, the pitch T shown in FIG. 4A is set to 1 second, 2 seconds, 60 seconds, 120 seconds, and 150 seconds, respectively, and swing control is performed on the strip 1 in a sinusoidal shape. . In Examples 6 to 10, the pitch T shown in FIG. 4B is set to 1 second, 2 seconds, 60 seconds, 120 seconds, and 150 seconds, respectively, and swing control is performed on the strip 1 in a triangular wave shape. In Examples 11 to 15, the pitch T shown in FIG. 4C is set to 1 second, 2 seconds, 60 seconds, 120 seconds, and 150 seconds, respectively, and swing control is performed on the strip 1 in a rectangular wave shape. In Comparative Example 1, the annealing separator slurry 4 is applied to the surface of the strip 1 without swinging the strip 1 as in the prior art. Table 1 is a table showing the results of Examples 1 to 15 and Comparative Example 1 described above.

  From Table 1, in Examples 1-15, it turns out that the generation | occurrence | production of the shape defect of the grain-oriented electrical steel sheet which is the strip | belt-shaped body 1 does not occur at all, or is reduced compared with the past. In contrast, in Comparative Example 1, it can be seen that a shape defect has occurred. From comparison between Examples 1 to 15 and Comparative Example 1, as in Examples 1 to 15, the band-shaped body conveying roll 5 and the squeeze roll 2 as the band-shaped body swinging means are swung to form the band-shaped body 1. On the other hand, it can be seen that the occurrence of shape defects in the grain-oriented electrical steel sheet can be suppressed by performing the swing control along the width direction.

  Further, in Table 1, when an example in which the shape defect is reduced is compared with an example in which there is no shape defect, the annealing separator slurry 4 is applied while the belt-like body 1 is swung with a pitch T of 2 to 120 seconds. Thus, it can be seen that shape defects do not occur in the grain-oriented electrical steel sheet. Therefore, it can be seen that the pitch T in the swing control for the strip 1 is preferably 2 to 120 seconds.

(Examples 16 to 21 and Comparative Example 2)
In Examples 16 to 21 and Comparative Example 2, first, a cold rolled sheet of a grain-oriented electrical steel sheet having a final sheet thickness of 0.23 mm and containing 3.4% by weight of silicon (Si) is used as the band 1. And after performing decarburization annealing with respect to this strip | belt body 1, the annealing separation agent slurry 4 was apply | coated to the strip | belt body 1 using the slurry application | coating apparatus 22 by a 2nd modification. Specifically, the coating amount of the annealing separator slurry 4 per one surface is oxidized on both surfaces of the strip 1 by setting the coating amount of the annealing separator slurry 4 per side to 7.0 g / m ² by the nozzle 3a before the rough coating roll and the nozzle 3b before the coating roll. Apply magnesium (MgO). Then, after winding the strip | belt-shaped body 1 into the coil 10, finish annealing is performed with respect to this coil 10 on 1200 degreeC temperature conditions. After the finish annealing, the shape of the belt-like body 1 is corrected in a flattening annealing furnace at a temperature of 850 ° C. And the presence or absence of the shape defect along a longitudinal direction was test | inspected visually with respect to the strip | belt-shaped body 1 by which shape correction was carried out.

  In Examples 16 to 21, when the annealing separator slurry 4 was applied to the surface of the strip 1, the strip 1 was swung based on the following technical idea.

  The effect of swinging the strip 1 in the width direction of the steel plate by the strip swinging means in the present invention is that a minute variation in the coating amount of the annealing separator slurry 4 due to the arrangement of the coating nozzle is caused by the strip 1. By dispersing in the width direction of the steel sheet, it is to promote the uniform application amount of the annealing separator slurry 4 on the strip 1. Furthermore, since this strip | belt-shaped body 1 is wound up after application | coating annealing separator slurry 4 and becomes a coil, the combination of the coating amount on the steel plate of the annealing separator slurry 4 which adjoins or adjoins to the radial direction of this coil is combined. It is considered more desirable to keep it constant.

  Based on such an idea, it is recalled that it is desirable to change the oscillation cycle of the strip 1 in consideration of the turn pitch of the coil wound around the strip 1. In the present embodiment, the belt-like body 1 is not swung for one cycle every one turn pitch, but is swung for one cycle every two turn pitches. As a result, the present inventors have found that there is a possibility that the total amount of the annealing separator slurry 4 applied between the layers of the coiled steel sheet may be further homogenized in the width direction of the steel sheet.

  Therefore, in Examples 16 to 21, the ratio (V / 2L) of the line speed V of the strip 1 to twice the turn pitch L of the coil 10 is defined as the turn pitch frequency (unit: [Hz]). The line speed V and the coil diameter of the coil 10 were set so that the turn pitch frequency was 0.665 Hz. At this time, the oscillation frequency of the strip 1 was changed within the range of 0.010 Hz to 1.000 Hz, and the annealing separator slurry 4 was applied to the surface of the strip 1. Moreover, the time change of the rocking | fluctuation amount of the strip | belt-shaped body 1 was controlled to the sine wave shape. On the other hand, in Comparative Example 2, the annealing separator slurry 4 was applied to the surface of the strip 1 without swinging the strip 1 as in the prior art. Table 2 shows the inspection results of the shape defects of the strip 1 in each of the above Examples 16 to 21 and Comparative Example 2.

  From Table 2, it can be seen that in Examples 16 to 21, there is no occurrence of the shape defect of the strip 1 (orientated electrical steel sheet), or it is reduced as compared with the prior art. Furthermore, in Examples 16 to 18, when the oscillation frequency of the strip 1 is close to the turn pitch frequency, that is, the same value as or close to 0.665 Hz, the shape failure of the strip 1 does not occur. I understand. On the other hand, in Comparative Example 2, it can be seen that the shape defect of the belt-like body 1 occurs.

  In Examples 16 to 21, the time change of the swing amount of the belt-like body 1 was controlled in a sine wave shape, but even when this time change of the swing amount is controlled in a rectangular wave shape or a triangular wave shape, There was no difference in the inspection result of the shape defect of the band 1.

  In Examples 16 to 21, the result when the turn pitch frequency is 0.665 Hz is shown. However, even if the turn pitch frequency is a value other than 0.665 Hz, the oscillation frequency of the strip 1 is turned. By approaching the pitch frequency, the same result as that obtained when the turn pitch frequency was 0.665 Hz was obtained.

  Furthermore, in Examples 16 to 21, the turn pitch frequency was set based on twice the turn pitch as described above, and the oscillation of the strip 1 was controlled based on this turn pitch frequency. As a result, good results as shown in Table 2 were obtained, but the turn pitch frequency was set based on coating conditions based on such a concept, that is, an even multiple of the turn pitch. The same effect was obtained when the strip 1 was swung in accordance with the turn pitch frequency.

  According to the embodiment of the present invention described above, when the annealing separator slurry 4 is applied to the surface of the strip 1, the strip 1 is moved along the width direction by the strip transport roll 5 and the squeeze roll 2. By swinging, the non-uniformity of the film thickness distribution of the annealing separator slurry 4 along the width direction is made smooth, or build-up is prevented when the strip 1 is wound up to form the coil 10. Therefore, it is possible to suppress the occurrence of shape defects in the band 1.

  Although one embodiment of the present invention has been specifically described above, the present invention is not limited to the above-described embodiment, and various modifications based on the technical idea of the present invention are possible. For example, the numerical values given in the above-described embodiment are merely examples, and different numerical values may be used as necessary.

  Specifically, in the above-described embodiment, the belt-shaped body 1 is swung using the belt-shaped body transport roll 5, but without using the belt-shaped body transport roll 5, the annealing separator application as a slurry coating device is applied. It is also possible to rock the strip 1 using a pinch roll or a bridle roll provided on the entry / exit side of the apparatus.

  In the above-described embodiment, the pitch T in the case where the swing control is performed on the strip 1 in a sine wave shape, a triangular wave shape, or a rectangular wave shape is set to 2 to 120 seconds, or the coil 10 has a turn pitch. In addition, the oscillation frequency of the band 1 is set to a predetermined value (for example, 0.665 Hz), but the period and frequency are various values corresponding to the line speed of the band 1 and the position after winding the coil 10. It is also possible to make it variable.

  In the above-described embodiment, the example in which the slurry supply nozzle 3 is fixed has been described. However, the slurry supply nozzle 3 is also swung together while adjusting the swing control with respect to the belt 1. May be.

DESCRIPTION OF SYMBOLS 1 Strip | belt body 2 Squeeze roll 2a Coarse application roll 2b Backup roll 2c Application | coating roll 3 Slurry supply nozzle 3a Nozzle before application | coating roll 3b Nozzle before application | coating roll 3c Nozzle after application | coating roll 4 Annealing separator slurry 5 Band | band conveyance roll 10 Coil 20, 21, 22, 23, 100 Slurry coating device

Claims (12)

Strip-shaped body swinging means configured to swing the strip-shaped body substantially parallel to the surface of the traveling strip-shaped body and substantially perpendicular to the traveling direction of the strip-shaped body;
Slurry discharge means configured to be able to supply slurry to the strip,
A pair of application means configured to be able to apply the supplied slurry onto the surface of the band-shaped body by pressing while holding the band-shaped body;
A slurry application apparatus comprising:   A second structure configured to be able to apply the slurry to the surface of the band-like body by pressing the belt-like body while holding the band-like body downstream of the pair of application means along the traveling direction of the band-like body. A pair of application | coating means is provided, The slurry application | coating apparatus of Claim 1 characterized by the above-mentioned.   A second slurry discharge means configured to be able to supply slurry to the traveling belt-like body is provided downstream of the pair of application means along the running direction of the belt-like body. The slurry coating apparatus according to claim 1 or 2.   The slurry application apparatus according to any one of claims 1 to 3, wherein the temporal change of the swing amount in the swing is a rectangular wave shape, a sine wave shape, or a triangular wave shape.   The slurry coating apparatus according to any one of claims 1 to 4, wherein the oscillation frequency of the strip is set based on a turn pitch of a coil formed by winding the strip.   6. The slurry coating apparatus according to claim 5, wherein the oscillation frequency of the belt-like body is set based on an even multiple of the turn pitch. A slurry supply step of supplying the slurry while swinging the traveling strip in a direction substantially parallel to the surface of the strip and substantially perpendicular to the traveling direction of the strip;
A slurry application step of applying the slurry to the surface of the band by pressing while holding the band supplied with the slurry;
The slurry application | coating method characterized by including.   8. The method according to claim 7, further comprising a second slurry application step of applying the slurry to the surface of the band-like body by pressing the slurry-like body supplied with the slurry after the slurry application step. The slurry application | coating method of description.   9. The slurry application method according to claim 7, further comprising a second slurry supply step of supplying the slurry to the traveling belt-like body after the slurry application step.   The slurry application method according to any one of claims 7 to 9, wherein the temporal change of the swing amount in the swing is a rectangular wave shape, a sine wave shape, or a triangular wave shape.   The slurry application method according to any one of claims 7 to 10, wherein an oscillation frequency of the band is set based on a turn pitch of a coil formed by winding the band.   The slurry coating method according to claim 11, wherein an oscillation frequency of the strip is set based on an even multiple of the turn pitch.

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