JPH01159323A - Iron loss decreasing device for grain oriented electrical steel sheet - Google Patents

Abstract

PURPOSE:To form micro-linear strains and to easily decrease the iron loss of a grain oriented electrical steel sheet by pressing the entire surface of the steel sheet passing continuously over a receiving base by a metallic mold having many micro-tooth profiles. CONSTITUTION:The grain oriented electrical steel sheet 1 prior to or after finish annealing or the steel sheet subjected to an insulating film treatment after the finish annealing is passed over the receiving base 7 of a press body 2 in an arrow direction by feed rolls 8. The linear tooth profiles 4 consisting of a cemented carbide, ceramics, diamond, etc., are mounted to the metallic mold 3 provided nearly orthogonal with the passing direction and the steel sheet 1 is pressurized by a forward/backward driving device 6, by which the very small compressive linear strains by the tooth profiles 4 are formed in the thickness direction of the steel sheet 1 over the entire part in the transverse direction of the steel sheet. The iron loss of the grain oriented electrical steel sheet is thereby largely decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application! F) The present invention relates to an apparatus for reducing iron loss by imparting minute compressive linear strain to the surface of a grain-oriented electrical steel sheet.

(Prior Art) There is a strong demand for improving the iron loss characteristics of grain-oriented electrical steel sheets from the viewpoint of energy saving, and various methods have been proposed to improve the iron loss characteristics.

One known method for improving the core loss characteristics of grain-oriented electrical steel sheets is to impart microstrains to the surface of the steel sheets.

For example, there is Japanese Patent Publication No. 58-5968. This is done by pressing small balls etc. onto the surface of the unidirectional electrical steel sheet after final finish annealing to form indentations with a depth of 5μ or less and applying linear microstrain to refine the magnetic domains and reduce iron loss. It is something that can be improved.

It is known that applying microstrain in a direction perpendicular to the rolling direction of a grain-oriented electrical steel sheet or in a direction inclined at a predetermined angle to the rolling direction is effective in improving iron loss.

By the way, as an industrial device for imparting linear minute dents to the surface of a grain-oriented electrical steel sheet, for example, Japanese Patent Laid-Open No. 60-96
Publication No. 719 describes an apparatus for creating minute indentations on the surface of a material to be treated using a roll in which a high-hardness material is embedded or thermally sprayed so as to form minute protrusions arranged in a linear arrangement parallel to the axis of the roll. . The roll provided with the minute protrusions is installed in a continuous line as a priddle roll, deflation roll, or dancer roll to form minute dents at intervals in the grain-oriented electrical steel sheet being passed through.

(Problems to be Solved by the Invention) A device that uses a roll having such protrusions to create linear minute indentations on the surface of a steel sheet has certain effects and contributes to improving magnetic properties. However, in such equipment, it is difficult to form the protrusions on the rolls, the manufacturing cost of new rolls and the cost of recycling worn rolls are high, and the protrusions on the rolls wear out as the work progresses, resulting in a relatively short lifespan. Furthermore, there is a problem that it is difficult to uniformly form minute dents over the entire width of the steel plate due to the shape of the steel plate and fluctuations in the tension of the steel plate during threading.

The present invention makes it possible to inexpensively and stably and continuously apply minute linear strain in the desired direction, size, and shape to the surface of a continuously passed steel sheet over a long period of time over the entire width of the sheet. The purpose of this invention is to provide a device that has a large iron loss improvement effect.

(Means for Solving the Problems) In order to achieve the above object, the present inventors conducted various experiments and conducted studies. As a result, a mold provided with one or more linear tooth profiles via a rolling force control device is connected to an advance/retreat drive device,
A press device consisting of a pedestal placed opposite the die and on the threading line of the grain-oriented electrical steel sheet produces compressive linear strain with only a load perpendicular to the surface of the grain-oriented electrical steel sheet. When applied at intervals, strong strain is introduced in the plate thickness direction, and when separate annealing is performed, new recrystallized grains that cause magnetic domain refinement appear in the compressive linear strain area, resulting in a significant reduction in iron loss. It was also found that this decrease did not disappear even after strain relief annealing was performed during subsequent core production.

The present invention will be described in detail below with reference to the drawings.

In the drawings, reference numeral 1 denotes a grain-oriented electrical steel sheet, and a steel sheet that has been treated with an insulating coating before or after final annealing or after final annealing is applied. The grain-oriented electrical steel sheet 1 is threaded in the direction of the arrow.

2 is the press body. 3 is a mold, and in this embodiment, a plurality of linear tooth profiles 4 are spaced apart from each other in the sheet passing direction.
That is, it is provided substantially perpendicular to the rolling direction of the grain-oriented electrical steel sheet 1. Linear tooth profile 4 is made of carbide metal, ceramic,
Although it is preferable to use diamond or the like, it is not necessary to specify the material.

Reference numeral 5 denotes a rolling force control device, which applies compressive linear strain to the grain-oriented electrical steel sheet 1 using a predetermined rolling blade. etc. are used.

One end of the rolling force control device 5 is connected to the mold 3, and the other end is connected to the linear tooth profile 4.

Reference numeral 6 denotes a forward/backward drive device which moves the linear tooth profile 4 forward and backward at high speed with respect to the grain-oriented electromagnetic steel sheet 1, and is connected to the mold 3.

As the linear tooth profile 4 advances and retreats, compressive linear strain is instantaneously applied to the grain-oriented electrical steel sheet 1.

At the time of application, the action of the rolling force control device 5 prevents the movement of the movement rod 6-1 of the movement drive device 6 even if its length changes due to thermal expansion or if there is a shape defect in the grain-oriented electrical steel sheet 1. Even if the rolling edge is applied to the steel plate 1 by the linear tooth profile 4, the rolling edge applied to the steel plate 1 is uniform over the entire width of the plate. The shape of the compressive linear strain imparted here is determined by the tooth profile shape of the mold,
The depth of compressive linear strain can be arbitrarily adjusted by the set load of the rolling force control device 5.

The interval of the compressive linear strain can be freely adjusted by the number and interval of the linear teeth 4 provided in the mold 3, the advancing/retreating speed by the advancing/retracting drive device 6, and the passing speed of the steel plate.

However, if this interval becomes narrower, the effect of subdividing the magnetic domains will decrease and the magnetic flux density will deteriorate, so it is preferably 1 mm or more. On the other hand, if the spacing becomes too wide, the effect of subdividing the magnetic domains will be reduced, so it is desirable that the spacing be 30 mm or less.

The direction of the compressive linear strain is preferably 90 degrees to 45 degrees with respect to the rolling direction of the grain-oriented electrical steel sheet, and the width of the strain is 1
It is preferable to set it as 0tlff1-300 pm.

The set load of the rolling force control device 5 for applying compressive linear strain is preferably 3 to 20 kg/am from the viewpoint of workability and prolonging the life of the press device.

Furthermore, if a plurality of flocculent tooth profiles 4 are provided at intervals, when applying compressive linear strain to the grain-oriented electrical steel sheet 1,
Since a compressive load is applied to the steel plate 1 at the same time by a plurality of linear tooth profiles 4, the process is performed in a restrained state. For this reason, no shape change occurs in the steel plate, and compressive linear strain is uniformly formed from this surface over the entire width of the plate.

Reference numeral 7 denotes a cradle, which faces the mold 3 and is provided in the threading line of the grain-oriented electromagnetic steel sheet. 8 is a feed roll.

(Example) Example weight %: C: 0.080, Si: 3.27, Mn:
0.074, AI! , :0.021, S:0.026
, Cu: o, 13, Sn: O, L 2 A silicon steel slab consisting of 2 balance iron was hot rolled, annealed and cold rolled by a well-known method to obtain a steel plate with a thickness of 0.220 mm.

Next, the well-known steps of decarburization annealing, application of an annealing separation agent, final finish annealing, and insulation coating treatment were carried out.

The obtained steel plate was subjected to a reduction blade of 10 kg/mm and a steel plate threading speed of 30 m using a device as shown in the drawing in which 10 protruding teeth were provided at 5 mm intervals and perpendicular to the steel plate rolling direction.
Compressive linear strain was applied at /min.

Next, annealing was performed at 800'CX for 2 hours, and the magnetic properties were measured.

The results are shown in the table below along with a comparative material that underwent the same process and was treated with an insulating coating.

(Effects of the Invention) As described above, according to the present invention, compressive linear strain having a large effect of reducing iron loss is uniformly formed in the grain-oriented electrical steel sheet over the entire width direction of the sheet.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1: Grain-oriented electromagnetic steel sheet, 2: Nibless body 3: Mold, 4: Linear tooth profile, 5: Rolling force control device, 6: Advance/retreat drive device.

Claims (1)

[Claims] A mold in which a linear tooth profile is provided via a rolling force control device is connected to an advance/retreat drive device, and a pedestal is provided opposite to the mold and in the threading line of the grain-oriented electrical steel sheet. Iron loss reduction device for grain-oriented electrical steel sheets.