JPH07110975B2 - Iron loss reduction processing line for grain-oriented electrical steel - Google Patents

Description

TECHNICAL FIELD The present invention relates to a line for performing an iron loss reduction process on a grain-oriented electrical steel sheet which has little deterioration in magnetic properties even when strain relief annealing is performed.

[Conventional technology]

With regard to grain-oriented electrical steel sheets, due to the recent energy situation,
Materials with lower iron loss are required. As a method for reducing iron loss, for example, as disclosed in Japanese Examined Patent Publication No. 58-5968, a method of imparting a linear minute strain to the surface of an electromagnetic steel sheet by means of a spherical rotor or a rotating disc, and Japanese Examined Patent Publication No. 57- As shown in Japanese Patent No. 2252, there is a method in which a magnetic domain is subdivided by applying strain by laser irradiation. All of the above prior art is an excellent method of significantly reducing the iron loss value of the electromagnetic steel sheet, but in order to remove the processing strain received when assembling the grain-oriented electrical steel sheet as the iron core of electrical equipment, 700 to 950 ° C. When the strain relief annealing to heat is used for the purpose of including it in the assembly process, the effect of the strain imparted to reduce the iron loss is removed by being heated to such a high temperature. In the grain-oriented electrical steel sheet used for the wound core transformer or the like included in the iron core assembling process, there remains a problem that the effect cannot be sufficiently exhibited.

As a method for solving this problem, that is, as a method for reducing the iron loss of grain-oriented electrical steel sheets so that the effect does not disappear even if the core is subjected to strain relief annealing after processing, JP-A-61-117218 discloses a finish annealing. A method of forming a groove in the range of 45 degrees from the right angle to the rolling direction on a magnetic steel sheet that has been subjected to an insulating film treatment after finished or finish annealing and then heat treating it at 750 ° C or higher has been proposed. It has been shown to use gear-shaped rolls as the device for forming the. In addition to the above publications, JP-B-60-14827 discloses the use of gear-shaped rolls as a means for applying strain to a steel sheet. As a gear type roll used for these iron loss reduction treatments of grain-oriented electrical steel sheets (hereinafter simply referred to as steel sheets)
As disclosed in Japanese Patent Application Laid-Open No. 61-15314 and Japanese Patent Application Laid-Open No. 61-106717, the protrusions, that is, the teeth 1 shown in FIG. Kaisho 61
In the embodiment disclosed in Japanese Patent Laid-Open No. 117218, the gear type roll 2 is opposed to the presser roll 4 as shown in FIG. 2, and the space between the two rolls is shown in FIG. It is usual to form the linear recess by passing the steel plate 5 while applying a predetermined pressure by a reduction mechanism omitting. This is because when the teeth 1 are parallel to the axial direction 3 of the gear-shaped roll 2 as shown in FIG. 3, the effect of reducing the iron loss of the steel plate is sufficient, but the total length of the teeth 1 is at the same time the steel plate. Gear bit roll 2 and presser roll 4 for biting into
This is because there is a problem that large vibration is likely to occur in the entire linear recess forming device including the above.

[Problems to be solved by the invention]

As shown in FIG. 1, when a linear recess is formed in the steel plate 5 by using a gear-shaped roll 2 in which teeth 1 are spirally formed on the roll peripheral surface, Steel plate 5 in between
Since forces act on each other in the direction perpendicular to the traveling direction (axial direction of the gear-shaped roll), the steel plate 5 is easily offset in the width direction,
It will result in difficulties in striping.

After the linear recess is formed in the steel plate 5 by the gear-shaped roll 2, the heat treatment is performed at a temperature of, for example, 750 ° C. or higher as shown in the above-mentioned JP-A-61-117218. In order to reduce the manufacturing cost by reducing the number of production process lines of the grain-oriented electrical steel sheet as much as possible, it is desirable to perform the linear recess forming treatment for the steel sheet 5 and the subsequent heat treatment on the same line.

Furthermore, not only in the case of a steel sheet that has been finish-annealed and has not yet been subjected to an insulation coating treatment after finish annealing, the steel sheet after the above-mentioned insulation coating treatment has also been repaired because the above-mentioned insulation coating was damaged by the treatment with the gear-shaped rolls. For steel sheets that must be processed, after iron loss reduction treatment by gear-shaped rolls, the application of an insulating film treatment liquid that is usually performed after finish annealing of grain-oriented electrical steel sheets and drying and baking after application must be performed. Since baking is generally performed at a temperature exceeding 750 ° C, the steel sheet to be subjected to the above-mentioned insulating film treatment should be subjected to heat treatment at a temperature of, for example, 750 ° C or higher after the linear recess forming treatment by the gear-shaped roll and insulation. It is more desirable to combine the heat treatment for baking the coating to reduce the manufacturing cost.

INDUSTRIAL APPLICABILITY The present invention is a processing line for performing iron loss reduction processing of grain-oriented electrical steel sheet using a gear-shaped roll, with less deviation of the steel sheet at the time of passing, and with the minimum number of treatment steps of the grain-oriented electrical steel sheet It is an object of the present invention to provide an iron loss reduction treatment line for grain-oriented electrical steel sheets that is kept to a minimum.

[Means for solving problems]

The present invention, in an iron loss reduction treatment line for grain-oriented electrical steel, a rewinding reel for winding back a finish-annealed grain-oriented electrical steel sheet or a grain-oriented electrical steel sheet subjected to an insulating film treatment after finish annealing and winding for winding. A take-up reel, and a tension edging device for steel plates is provided in the middle of the both reels, and the line is divided into a high tension part on the entry side of the tension edging device and a low tension part on the exit side of the tension edging device. A high-tensile part is equipped with a device to prevent deviation of the steel plate. A gear-shaped roll forming device is provided on the steel plate to form a linear recess. A low-tensile part is equipped with a coating machine for applying the insulation film treatment liquid and a dry baking oven for the insulation film. It is characterized by consisting of.

The contents of the present invention will be described below with reference to an embodiment shown in FIG.

In FIG. 4, 11 is a rewinding reel, 12 is a take-up reel, and 13 is a tension edging device which divides the line into a high tension portion indicated by A and a low tension portion indicated by B, and in this embodiment, 14 It is composed of bridle rolls.

The high tension portion A is provided with a linear recess forming device 16 provided with a deviation preventing device 15. The deviation preventing device 15 includes rolls 17 and 17 'as main constituent elements in the embodiment of FIG. The linear recess forming device 16 comprises a gear-shaped roll 2, a pressing roll 4, a backup roll 6 and a not-shown mechanism for pushing down the backup roll 6 in the direction of the arrow (push-up mechanism).

On the other hand, in the low tension portion B, a roll coater type insulation film coating machine 18 and a heat treatment furnace which is used both for drying and baking the insulation film and for heat treatment at 750 ° C. or higher in the example of the above-mentioned JP-A-61-117218. (Hereinafter simply referred to as a drying oven) 19
Is installed.

In the embodiment shown in FIG. 4, in addition to the basic constituent elements of the above 11 to 19 constituting the iron loss reduction processing line of the present invention,
Entry side pinch roll 31, entry side shear 32, welder 33, surplus magnesia water washing device 34, entry side loop device 35, pickling device 36,
Drying furnace outlet bridle roll device 37, outlet loop device 3
8, the outlet shear 39, the outlet pinch roll 40, and the deflector roll 41 of each part are included as elements constituting the line.

FIG. 5 is an enlarged view of the vicinity of the linear recess forming device 16 of FIG. 4, 51 is a support stand for the roll 17 ′, and 52 is the position adjustment of the roll 17 ′ together with the support stand 51 in the traveling direction of the steel plate 5. This is a fluid pressure cylinder for this purpose, and in FIG. 4, the support base 51 and the fluid pressure cylinder 52 are not shown.

The steel plate 5 rewound by the rewind reel 11 is a pinch roll on the entry side.
After pulling out at 31, the defective portion is cut and removed at the inlet side shear 32, it is joined to the preceding steel plate at the welder 33, and the magnesia applied in the process immediately before finish annealing is mainly performed at the water washing device 34. Of the annealing separator as a component, so-called surplus magnesia other than that which contributed to the formation of the glass cover by the finish annealing is washed off with water.

Next, the steel plate 5 is further processed by the linear recess forming device 16 after the excess magnesia is further sufficiently removed by the pickling device 36 through the entrance side loop device 35. In this case, when the processing is performed using the gear-shaped roll 2 shown in FIG. 1 in which teeth are spirally formed on the circumferential surface of the roll as described above, the steel plate 5 is likely to be offset in the plate width direction. This is a problem when using such a gear-shaped roll 2. Therefore, this gear-shaped roll 2
It is necessary to attach a deviation preventing device when forming a linear depression in a steel sheet using the above method. However, according to the knowledge of the present inventors, the deviation of the steel sheet 5 is caused by the linear depression forming treatment. It is also greatly affected by the tension of the steel plate inside.

The magnitude of the tension of the steel plate 5, that is, the back tension on the entry side of the gear-shaped roll 2 (the position indicated by a in FIG. 5) is
When the size of the steel sheet 5 per unit cross-sectional area, that is, in the unit tension range of more than 1.0 kg / mm ² , the poor sheet passing property due to the deviation of the steel sheet 5 is remarkably improved. The larger the back tension is, the more stable the sheet-passing property becomes. However, if the unit tension applied to the steel plate 5 during the linear recess forming process is too large, an extra strain is introduced. Since the magnetism is deteriorated and the risk of breakage increases, it is appropriate that the tension applied to the steel plate 5 during the linear recess forming process is 7 kg / mm ² or less. The above-mentioned steel plate tension is basically given by the tension edging device 13 and the rewinding reel 11 shown in FIG. 4 in cooperation, but in the case of the line configuration in the embodiment of FIG. 35 and the offset prevention device 15 are also involved in determining the steel plate tension.

In the present embodiment, as a soot offset preventing device attached to the linear recess forming device 16, as shown in FIG. 5, when it is easy to offset, the offset is prevented by increasing the winding angle α with respect to the roll 17. The method to do is adopted. As a method of adjusting the winding angle α, as shown in FIG. 5, the position of the roll 17 'is changed by the fluid pressure cylinder 52. However, the deviation prevention device is not limited to the method of this embodiment, and a method normally used in the processing line of steel strips, for example, a crown in which the center of the roll 17 in FIGS. 4 and 5 is thicker than both ends is used. As shown in FIG. 6, a side view is shown in front of the linear recess forming device 16, and a plan view is shown in FIG.
Install a roll 8 for centering, and roll 8
May be rotated as indicated by arrow b in FIG. 7 or moved as indicated by arrow c to center the steel sheet 5. However, generally speaking, in the iron loss reduction treatment line of the present invention, not only the line is passed straight through the steel plate 5, but also linear recesses are formed uniformly in the width direction of the steel plate 5. Since it is important to obtain a uniform magnetic property in the width direction, it is inappropriate to add a crown to the gear roll 2 only for the purpose of threading. A centering method in which the steel plate 5 is not hit by a uniform pressure in the width direction of the gear roll 2 or the press roll must be avoided.

As described above, in the present invention, the adjustment of the steel plate tension during the linear recess forming process and the offset prevention device are made to cooperate with each other, for example, in the case of a steel plate having an easily offset shape, the tension is increased, or too much. In the case of a material which is not desired to be tensioned, the tension is reduced and the wrap angle with respect to the roll 17 is increased instead to prevent the steel sheet 5 from being offset.

In FIG. 4, the steel plate 5 which has been subjected to the linear concave portion forming treatment by the gear-shaped roll 2 passes through the tension edging device 13 and enters the low tension portion B of the line, and the insulating coating treatment machine 18 removes the insulating coating treatment liquid. After the coating, in the drying oven 19, the insulating film is dried and baked at a temperature of 750 ° C or higher, preferably 800 ° C or higher, and shape correction such as winding curl generated during finish annealing is performed.
Further, in the case of the above-mentioned Japanese Patent Laid-Open No. 61-117218, it also serves as a heat treatment to be performed at 750 ° C. or higher.

The tension applied to the steel plate during this heat treatment is 0.1 to 1.0 kg / mm ²
If the range is 1 kg / mm ² or more, the risk of stretching or cracking in the high temperature steel plate increases, and the magnetism deteriorates.
If it is less than 1 kg / mm ² , the above-mentioned shape correction becomes insufficient and good magnetism cannot be obtained.

As described above, since the applied steel plate tension range is different between the linear recess forming device 16 portion and the drying oven 19 portion, in the present invention, the tension edging device 13 divides the line into a high tension portion and a low tension portion. It's what we share. In the embodiment shown in FIG. 4, the heat-treated steel plate 5 is passed through the furnace exit side bridle roll device 37 and the exit side loop device 38, and the take-up reel 12
Is wound into a coil.

The above has been described on the basis of the case where iron loss reduction treatment is performed on the coil as it is after finish annealing, but when performing treatment with a gear-shaped roll on a steel sheet that has already been subjected to insulating film treatment after finish annealing, On the inlet side, the removal of excess magnesia by the water washing device 34 and the pickling device 36 can be omitted, and further, when re-coating is not necessary without damaging the insulating film already applied by the gear-shaped roll treatment, The iron loss reduction process can be performed in any of the lines of the present invention, with the only difference that the coating in the insulating film coating machine 18 may be omitted and only the heat treatment in the drying furnace 19 may be performed.

〔Example〕

An example in which the iron loss reduction process is performed on the line having the configuration shown in FIG. 4 will be described below.

Plate material: Finished annealed grain-oriented electrical steel sheet with plate thickness 0.23 mm and plate width about 1000 mm Gear-shaped roll: tooth inclination of 15 degrees with respect to roll axis direction, gear pitch 5 mm, gear tip tooth width 50 μm, tooth tip flat Working conditions: line speed 100 mpm, wrapping angle of steel plate to gear type roll 2 ≈135 ° and 0 °, coating machine 18 at the low tension part B of the line on the steel plate after the linear recess forming process by gear type roll 2 After applying the tension imparting type insulation coating solution with the, the tension is 0.6kg / mm ² , the temperature is 850 ℃ in the drying oven 19.
Heat treatment was performed at.

Under the above conditions, the back tension of the steel plate 5 and the wrapping angle α with respect to the roll 17 during the linear concave portion forming process in the gear roll 2 were changed, and the results shown in Table 1 were obtained for the threadability.

The winding angle α = 0 in Table 1 means that the steel plate 5 does not pass through the roll 17 as shown by the broken line in FIG. In the table, x means that it is impossible to pass the steel sheet due to the deviation of the steel plate, and Δ mark shows that the deviation is considerably improved but the deviation is larger than ± 1.0 mm. Unstable means that stable threading was completed.

In Table 1, an example of magnetism after strain relief annealing of a steel sheet subjected to iron loss reduction treatment with a tension of 1.5 kg / mm ² and a wrapping angle α of 135 degrees is shown for reference, B ₁₀ = 1.90T, W17 / 50 = 0.79W / kg is obtained.

〔The invention's effect〕

 According to the present invention, the following effects can be obtained.

In the iron loss reduction processing line of grain-oriented electrical steel sheet using a gear type roll, the line is divided into a high tension part and a low tension part by a tension edging device, and a steel plate deviation prevention device is attached to the high tension part. By forming a linear recess forming device on the steel plate with a shaped roll, and by installing a coating machine for coating the insulating film treatment liquid and a drying baking oven for the insulating film on the low-tension part, the linear recess is formed on the steel plate with a gear-shaped roll. Prevents deviation of the steel sheet when forming it, and performs subsequent heat treatment and insulation coating treatment on the same line to minimize the production of grain-oriented electrical steel sheets whose iron loss does not deteriorate even when strain relief annealing is performed. It can be performed stably in the treatment process.

[Brief description of drawings]

FIG. 1 is a front view of a gear-shaped roll having teeth inclined with respect to the roll axis, FIG. 2 is a side view showing an example of a gear-shaped roll during steel plate processing, and FIG. Fig. 4 is a front view of a gear-shaped roll parallel to Fig. 4, Fig. 4 is a diagram showing an embodiment of an iron loss reduction processing line according to the present invention, Fig. 5 is a partially enlarged view of Fig. 4, and Fig. 6 is an example of a centering method. 7 in a side view showing
The figure is a plan view of the device shown in FIG. 1 ... Tooth, 2 ... Gear-shaped roll, 4 ... Press roll, 5 ... Steel plate, 6 ... Backup roll, 11 ... Rewind reel, 12 ... Take-up reel, 13 ... Tension trimming device, 15 …… Offset prevention device, 16 …… Linear recess forming device, 18 …… Insulation film coating machine, 19 …… Insulation film dry baking furnace.

Claims (2)

[Claims] 1. A rewinding reel for rewinding a finish-annealed grain-oriented electrical steel sheet or a grain-oriented electrical steel sheet subjected to an insulating film treatment after finish-annealing, and a take-up reel for winding up. A tension edging device for steel plate is provided in the middle, and the line is divided into a high tension part on the entry side of the tension edging device and a low tension part on the exit side of the tension edging device, and a device for preventing deviation of the steel plate on the high tension part. A grain-oriented electrical steel sheet characterized by being provided with a device for forming linear recesses in a steel sheet by means of an attached gear-shaped roll, and a coating machine for coating an insulating coating solution and a drying / baking furnace for insulating coating in the low tension portion. Iron loss reduction processing line. 2. The steel sheet tension is 1.0 to 7.0 kg / m in the high tension portion.
The iron loss reduction processing line for grain-oriented electrical steel according to claim 1, which is held at 0.1 to 1.0 kg / mm ² in a m ² and low tension portion.