JPS5873724A - Directional electromagnetic steel plate - Google Patents

Abstract

PURPOSE:To manufacture a directional electromagnetic steel plate whose iron loss characteristics is excellent, by forming a local laser irradiation mark at an almost right angle in the rolling direction onto the surface of a finish-annealed electromagnetic steel plate. CONSTITUTION:On the surface of a steel plate 1 of coarse grain, which has formed (110)[001] structure by recrystallization annealing in advance, a local laser irradiation mark 5 is formed at an almost right angle in the rolling direction, by irradiating a laser beam through a slit 3 from a laser oscillating device 2. As for said laser irradiation mark 5, it is desirable that width (d) is 0.1-1mm., an irradiation interval (l) is 1-20mm., and also it is in the direction of 30 deg. or less from the right angle direction against the rolling direction. Also, it is suitable that energy density of the laser beam is 0.07-10 J/cm<2> (time width is 1ns- 100ms or so).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a round grain-oriented electrical steel sheet with excellent core loss characteristics, the surface of which is irradiated with laser light to form radar irradiation marks locally.

There are two types of grain-oriented electrical steel sheets. However, those produced industrially and mainly used as core materials for transformers and other electrical equipment are usually crystallographically (110
) [001] structure, which means that the (110) plane of each grain in the steel sheet is parallel to the sheet surface, and the axis of easy magnetization [001] is in the rolling direction. This means that they are parallel.

and ζ is (110) of each grain in an actual steel plate.
The surface is slightly inclined from the surface shown, and the (001) direction is also slightly deviated from the rolling direction. By the way, since the excitation a% and iron loss of electrical steel sheets are greatly influenced by the degree of deviation, all crystal grains are (110) (00
1) A great deal of effort has been made to get closer to the ideal orientation. As a result, currently when the plate thickness is 0.3'0 haze,
Electrical steel sheets with a low iron loss value of around 1.03 W/kII at W1715° are being produced industrially.

(Here, W and A15° are the iron loss at a magnetic flux density of 1.7T and 50Hg.) However, recently, in order to dramatically reduce the iron loss below this value, it is necessary to bring each crystal grain close to the ideal orientation. It is becoming increasingly clear that it is difficult to do just that. The reason for this is that iron loss generally depends on grain size in addition to excitation characteristics, so the decrease in iron loss due to improved excitation characteristics is offset by the increase in crystal grain size that is normally experienced in efforts to improve excitation characteristics. This is because it will be done. In other words, the conclusion is that it is by no means easy to achieve a dramatic reduction in iron loss using conventional metallurgical means. Therefore, unless methods other than metallurgical means are used, no further improvement in iron loss characteristics can be expected.

As one of such means, a method of applying tension to a steel plate is known. Specifically, a specific method thereof is a method of applying tension using a permeable film. However, there is a limit to the tension created by this film, which makes it difficult to
There is also a limit to the iron loss (4I). In other words, even if the film tensioning effect is taken into account, the best properties obtained are O1,0 as mentioned above.
It's about 3W/kl. stomach. Another method is to make sharp scratches on the surface of the steel plate with the edge of a knife, or with diamond sand or Kintawashi Misaki. Although it is true that this method can be expected to reduce iron loss in veneer, the fate of mechanical methods is that the surface is severely uneven due to the formation of scratches (in other words, the edges of the scratches become raised). There are defects such as not only significant deterioration of the laminated field umbrella truck but also a significant increase in magnetostriction, and furthermore, there are fatal defects such as the iron loss value of the laminated steel plate not reaching the specified value. Even defects occur. In other words, the Nigelstein measurement value becomes higher than the SST (single plate measuring instrument) measurement value. The reason for this is presumed to be as follows. In other words, since the thickness of the plate is locally thinner in the recessed areas where scratches occur, part of the magnetic flux goes out of the steel plate and is transferred to the adjacent steel plates above and below the laminated steel plate, resulting in the magnetic flux perpendicular to the steel plate. When a magnetization component occurs and deteriorates iron loss, it becomes k.

For the above reasons, the scratches that cause mechanical scratches on the surface of the steel plate are
This is not the preferred method for iron cores constructed by laminating steel plates, and cannot be used in some cases.

It is also known that iron loss decreases when scratches are made at approximately 10 m intervals perpendicular to the rolling direction of the steel plate, with a width of approximately 0.1 m and a concave cross section of approximately 15 to 30 μm. This is thought to be due to a decrease in eddy current loss. However, this method is also a mechanical method, and the edges of the rounded and scratched portions are raised] and when laminated as an iron core, the space factor decreases, which is undesirable.

The present invention relates to a oriented electromagnetic copper plate with excellent iron loss characteristics obtained by completely independent means without relying on such conventional techniques.

That is, as shown in FIG. 1, the present invention provides a #1 i! This invention relates to a grain-oriented electrical steel sheet in which core loss characteristics are improved by irradiating a radar beam at right angles to form radar irradiation marks 5. Figures 2 and 3 show an actual example of manufacturing grain-oriented electrical steel sheets according to the present invention.
This is a slot interposed between the shell expansion oscillator 2 and the steel plate 1.

FIG. 3 shows a different example from that shown in FIG. 2, which is a reflecting mirror for reflecting the radar light emitted from the four-channel radar oscillator 2 and focusing it on the steel plate 5.

Note that the radar irradiation marks included in the present invention are lll11(d).
0.1~l■, spacing in the rolling direction (Lt) 1~20-, and the energy density Φ) of the irradiated radar light is 0.
．． 07~10 J/lxi' (time width 1'ns~10
0 ms) is preferable. Furthermore, there is no particular limitation on the radar used.

Next, examples of the present invention will be shown.

Example 1 Nonal Slade energy density & P = 0.8 J
/ctn2 Irradiation distance t = 10 ■ Irradiation width d = 0.1 mm When a magnetic steel sheet with a thickness of 0.30 mm was irradiated with laser f-hi-A, the iron loss reduction ΔW was 0.02 (W /ni9)
Met. However, the magnetic flux density FiB8 before irradiation is 1.93
5 pieces) and 1.934 pieces after irradiation, similarly the iron loss value w17/
so is 1.10 (W/Icy) before irradiation and 1.0 after irradiation.
08 (expletive) It happened. In other words, ΔW is subtraction 0
．． 02 (W/Ni9). This value is the minimum value for iron loss reduction.

Example 2 Arm laser energy density P 2. OJ/cm2
When a laser beam was irradiated on an electrical steel sheet with a thickness of 0.30 under the conditions of irradiation interval t = S haze irradiation width d = 0.25■, the IW was 0.10 ('%%7 to 9). .

However, the magnetic flux density B8 before irradiation is 1.954 (I5 is 1.952 (1), and similarly the iron loss value W1. /
It decreased to 9). That is, 2w = 6.1o (W
AI). This value is sufficient to improve the grade of the electrical steel sheet by one rank or more.

Example 3 Pulsed laser - energy density P = 1. IJ/
ex' Irradiation interval Irradiation interval Cylinder irradiation width d: 0.1■ Normal insulating film applied: When a radar beam was irradiated on an electromagnetic steel sheet with a thickness of 9, jW = 0,
04 (W/Ni9). 88 before irradiation is 1.9
27 (a) after irradiation 1.925 cr), iron loss value "17/
50 is from the same hometown K 1.09 (WAI) is 1. os
It became (wow). Therefore, ΔW=0.04 (W skin).

Example 4 Nolls laser energy density P = 1.2 J/
When a laser beam was irradiated on an electrical steel sheet with a thickness of j and 35 cm under the conditions of cm2 irradiation interval t = 10 wm and irradiation @ d = 0.35 cm, the iron loss reduction ΔW was 0.08 (W/k
g). However, the magnetic flux density B8 and iron loss value W1715° (WAg) before and after irradiation were as follows.

88 = 1.927T' W1715 before irradiation (+ = 1.14W/kg 88 = 1.9267 IW after irradiation, 715o = 1.06WA Note that the radar irradiation marks in the grain-oriented electrical steel sheet of the present invention are in the rolling direction - It is preferable that the angle is approximately perpendicular to 8. Strictly perpendicular angle, squareness is good, and deviations up to a maximum of .

Further, according to the present invention, even when the surface of an electromagnetic copper plate is coated with an insulating film and then irradiated with a laser beam, laser irradiation marks, that is, minute strains can be formed, so that iron loss characteristics can be improved.

As explained above, the present invention can provide a grain-oriented electrical steel sheet with extremely low iron loss.

4. Brief Description of the Drawings FIG. 1 is a plan view of the steel plate of the present invention, and FIGS. 2 and 3 are explanatory diagrams showing an example of manufacturing the steel plate of the present invention.

1: Steel plate, 2: Laser oscillation device, 3: Pickpocket.

4: Reflector, 5: Laser irradiation trace.

Fan diagram Collection 3 illustration

Claims (3)

[Claims] (1) A grain-oriented electrical steel sheet with a finish-sintered purity that has localized radar irradiation marks on its surface almost perpendicular to the rolling direction. (2) Width of radar irradiation mark (d) is 0.1 to 1■
The grain-oriented electrical steel sheet according to claim 1, wherein the irradiation interval (a) is 1 to 20 cm. (3) The oriented electromagnetic copper sheet according to claim 1, wherein the laser irradiation marks are in a direction within 30° from a direction perpendicular to the rolling direction.