JPH0660349B2 - Iron loss value reduction device for grain-oriented electrical steel - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an apparatus for stably forming a minute compressive linear strain on the surface of a grain-oriented electrical steel sheet to reduce iron loss.

(Prior Art) In the grain-oriented electrical steel sheet, it is strongly demanded to improve the iron loss characteristics from the viewpoint of energy saving, and studies have been made to improve the iron loss characteristics, and various methods have been provided.

As one of the methods for improving the iron loss characteristics of grain-oriented electrical steel sheets, a method of imparting a microstrain to the surface of the steel sheet is known.

For example, there is Japanese Patent Publication No. 58-5968. This is because the small spheres etc. are pressed on the surface of the unidirectional electrical steel sheet after the final finish annealing to form dents with a depth of 5 μm or less and a linear microstrain is applied to subdivide the magnetic domains to reduce iron loss. To improve.

It is known that it is effective to improve the iron loss by applying the minute strain in a direction orthogonal to the rolling direction of the grain-oriented electrical steel sheet or in a direction inclined by a predetermined angle with respect to the rolling direction.

By the way, as an industrial device for imparting linear minute dents in a grain-oriented electrical steel sheet, for example, JP-A-60-96719 discloses that minute protrusions in a linear array parallel to the axial direction of a roll are formed. There is described an apparatus for imparting a minute dent to the surface of a material to be processed by using a roll in which a high hardness substance is embedded or sprayed. The roll provided with the minute protrusions is incorporated in a continuous line as a bridle roll, a deflector roll, or a dancer roll so that minute dents are formed at intervals on the grain-oriented electrical steel sheet.

An apparatus for imparting a linear minute dent to the surface of a steel sheet by using a roll having such a protrusion has a certain effect and contributes to the improvement of magnetic properties, however, in such an apparatus, the roll It is difficult to form protrusions,
The manufacturing cost of new rolls and the cost of reclaiming worn rolls are high, the protrusions of rolls wear down as the work progresses, and the service life is relatively short. Due to the influence of, it is difficult to uniformly form fine dents over the entire width of the steel sheet.

(Problems to be Solved by the Invention) By the way, the grain-oriented electrical steel sheets to be produced have various widths such as a wide material or a narrow material.

Further, the steel plate has a plate thickness slightly larger at the center in the plate width direction than at the ends, as is called a crown. Further, even though the technology for producing grain-oriented electrical steel sheets has advanced, there are some steel sheets that extend inward and have a plate shape called an ear wave.

The present invention provides a device with which a desired minute linear strain can be stably and continuously formed over the entire sheet width direction even for such a grain-oriented electrical steel sheet, and the iron loss improving effect is great. The purpose is to do.

(Means for Solving Problems) The inventors of the present invention have found that when a compressive linear strain is applied to a grain-oriented electrical steel sheet with a force only in a direction perpendicular to the sheet surface at intervals, the strain occurs in the sheet thickness direction. Is strongly introduced, and if it is subsequently annealed separately, new recrystallized grains that cause magnetic domain refinement appear in the compressive linear strained part, and the iron loss is significantly reduced, and the decrease is caused by the subsequent winding. It was found that it does not disappear even if stress relief annealing is applied at the time of manufacturing the iron core.

The present invention is an apparatus that reliably applies a compressive linear strain that can provide an iron loss improving effect regardless of how the grain size of the grain-oriented electrical steel sheet changes and the plate shape.

Hereinafter, the present invention will be described in detail with reference to the drawings.

In the drawings, 1 is a grain-oriented electrical steel sheet, and a steel sheet that has been subjected to an insulating coating before or after finish annealing and further after finish annealing is applied. The grain-oriented electrical steel sheet 1 is passed in the direction of the arrow.

2 is a press body, and 3 is a mold. Reference numeral 4 is an integral elastic tooth shape, and linear teeth 5 of the same elastic body are provided at intervals in this embodiment. Further, the good elastic tooth profile 4 is connected to the mold 3 through a rolling force control device 6, for example, a fluid pressure cylinder such as a hydraulic cylinder or a pneumatic cylinder, a highly rigid spring, a shock absorber or the like. A plurality of rolling force control devices 6 are provided in the width direction of the steel plate, and the rolling force in the width direction of the steel plate can be changed. The good elastic tooth profile 4 is made of a highly elastic material such as spring steel, mild steel or thin-walled cemented metal, and is elastically moved by the force from the rolling force control device 6, as shown in FIG. Familiar with the plate shape of the grain-oriented electrical steel sheet 1 that imparts compressive linear strain, the sheet width direction or longitudinal direction (rolling direction)
A compressive linear strain can be uniformly formed over the entire length.
In order to evenly contact the linear teeth 5 with the crown of the steel plate, the shape of the linear teeth 5 itself may be a crown shape, but the width and the crown value of the grain-oriented electrical steel sheet to be manufactured are various. Therefore, in order to deal with these various things, the steel plate to be passed must be reassembled into the suitable linear teeth 5 each time. According to the good elastic tooth profile 4 of the present invention, such a problem is solved all at once, and even if any grain-oriented electrical steel sheet 1 has, for example, medium elongation in the sheet shape, it is not affected by it and a desired compressive linear strain is generated. Can be formed.

In this embodiment, the direction of the linear teeth 5 is provided substantially orthogonal to the sheet passing direction, that is, the rolling direction of the grain-oriented electrical steel sheet 1. You can incline up to the direction you want.

Reference numeral 7 denotes an advancing / retreating drive device for moving the linear teeth 5 forward / backward with respect to the grain-oriented electrical steel sheet 1 at high speed.

As the linear teeth 5 move back and forth, a compressive linear strain is instantaneously applied to the grain-oriented electrical steel sheet 1.

Reference numeral 8 is a pedestal, which is located in the strip passing line.

Reference numeral 9 is a feed roll, which is provided on the inlet side and the outlet side of the press body.

By the way, the formation interval of the compression linear strain can be adjusted by the number and intervals of the linear teeth 5 provided on the die 3, the advancing / retreating speed by the advancing / retreating drive device 7, and the passing speed of the steel plate. However, if the spacing is narrowed, the effect of subdividing the magnetic domains is reduced and the magnetic flux density is deteriorated.
On the other hand, if the distance is too wide, the effect of subdividing the magnetic domains will be small in this case as well, so 30 mm or less is desirable. The set load of the rolling force control device 6 for applying the compression linear strain is 3 to 3 from the viewpoints of workability and prolongation of the life of the press device.
20 kg / mm is preferred.

(Example) Example C: 0.083, Si: 3.26, Mn: 0.07 by weight%
3, Al: 0.029, S: 0.028, Cu: 0.11, S
A silicon steel slab consisting of n: 0.14 and the balance of iron was subjected to hot rolling-annealing-cold rolling by a known method to obtain a steel plate having a thickness of 0.220 mm.

Then, each step of well-known decarburization annealing-annealing separating agent application-final finish annealing-insulating coating treatment was carried out.

With respect to the obtained steel sheet, a device having a good elastic body made of a super hard metal having a thickness of 5 mm was provided with 10 linear teeth at 5 mm intervals orthogonal to the rolling direction of the steel sheet, as shown in the drawing. A compressive linear strain was applied with a rolling force of 12 kg / mm. When the applied state was investigated, a compression linear strain was formed uniformly over the entire plate width. Then, annealing was performed at 800 ° C. for 2 hours to measure the magnetic properties. The results are shown in the table below together with those of the comparative material which was treated in the same process and was subjected to the insulating film treatment.

(Advantages of the Invention) According to the present invention, as described above, a large compressive linear strain of iron loss reduction hardening is formed on the grain-oriented electrical steel sheet without being affected by the plate shape or the like.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing an embodiment of the present invention, and FIG. 2 is a diagram for explaining the operation of the present invention. 1: grain-oriented electrical steel sheet, 2: press body, 3: mold, 4:
Good elastic body tooth profile, 5: linear teeth, 6: rolling force control device, 7:
Forward / backward drive device, 8: pedestal, 9: feed roll.

Claims (1)

[Claims] Claim: What is claimed is: 1. In a device for reducing iron loss in a device for reducing core loss by advancing and retracting a die provided with linear teeth to form compressive linear strains in a grain-oriented electrical steel sheet at intervals. Core teeth are formed on the surface of the grain-oriented electrical steel sheet side, and it is connected to the die via a roll-down force control device with a variable rolling-force setting value in the width direction of the steel sheet. apparatus.