JPH0649903B2 - Iron loss improving device for grain-oriented silicon steel sheet - Google Patents

Description

Description: (Industrial field of application) Reducing iron loss in grain-oriented silicon steel sheets used for transformers, etc. In this specification, development of an iron loss improving device using plasma flame radiation is described. Describe the results of the research.

The iron loss of grain-oriented silicon steel sheet is a thermal energy loss mainly generated when it is used for iron cores of transformers and the like, and there is a demand to reduce the iron loss of grain-oriented silicon steel sheet due to the recent energy situation. It is increasing.

By the way, in order to reduce iron loss, the crystal orientation of the steel sheet should be (11
0) <001> orientation is highly aligned, increasing the Si content to increase the electrical resistance of the steel sheet, reducing impurities, and in recent years various attempts have been made to reduce the thickness of the steel sheet, etc. It was

However, the reduction of iron loss by these metallurgical methods has almost reached the limit.

(Prior Art) Various methods for reducing iron loss have been proposed in addition to metallurgical methods.

For example, Japanese Patent Publication No. 57-2252 discloses a method of reducing iron loss by laser irradiation. Although the iron loss can be greatly reduced by this method, it is inevitable that the initial cost and the running cost are increased due to the expensive equipment and the short life of the laser excitation lamp.

(Problems to be solved by the invention) On the other hand, the inventors of the present invention disclosed in Japanese Patent Laid-Open No. 62-96617, the above-mentioned method, by radiating a plasma flame to a grain-finished grain-oriented silicon steel sheet. We have proposed a method for improving iron loss of grain-oriented silicon steel sheets, which has no such drawbacks and can reduce iron loss in terms of productivity, workability, safety, and cost.

That is, since this method is advantageous in actual operation, it is desirable to apply this method to industrial scale production, and therefore, to provide an apparatus suitable for realizing industrial scale production by this method. It is an object of the invention to provide.

(Means for Solving the Problems) As a result of repeated experiments on the plasma flame radiation, the inventors have found that the surface of the finish-annealed grain-oriented silicon steel sheet has a plasma flame in a direction substantially orthogonal to the rolling direction of the steel sheet. It has been newly found that irradiating iron can significantly reduce iron loss, and by incorporating an optimum device for plasma flame radiation in a continuous line, industrial production can be performed without causing a significant increase in manufacturing cost. It was found to be applicable.

That is, the present invention, a rotary drum that guides the running of the finish-annealed grain-oriented silicon steel sheet in the rolling direction, and a ring-shaped drum that moves in concentric circles with the grain-oriented silicon steel sheet traveling on the drum in synchronization. And a plasma flame radiation torch that moves in a direction crossing the rolling direction of the grain-oriented silicon steel sheet.

The apparatus of FIG. 1 according to the present invention will be described below.

In the figure, 1 is a grain-finished grain-oriented silicon steel sheet (hereinafter referred to as a steel sheet), which is wound around a rotary drum 2 and run in a rolling direction at a constant speed.

Further, a plurality of plasma flame radiation torches 4 are mounted on a circular arc-shaped rail 3 installed concentrically with the rotating drum 2 under the support of a moving bearing 5, and the plasma flame radiation torches 4 are mounted on the rail 3 in synchronization with the steel plate 1. Run. That is, the moving speed of the plasma flame radiation torch 4 is set such that the relative speed between the steel plate 1 and the plasma flame radiation torch 4 becomes zero. If the moving bearing 5 is moved in the plate width direction of the steel plate 1 in this state, the plasma flame radiation torch 4 moves in a direction transverse to the rolling direction of the steel plate 1, and plasma flame can be radiated on the surface of the steel plate 1. .

The installation intervals of the plasma flame radiating torches 4 are set so that the radiating intervals of the plasma flames to the steel plate 1 are 2 to 30 mm, the nozzle holes of the torch 4 are 2.0 mmφ or less, and the output current is 1 to 300
The range of A is suitable.

The plasma flame may be either non-transfer type or transfer type, but the non-transfer type is easier to radiate. The gas for plasma generation is preferably an inert gas such as Ar, N ₂ or H ₂ and a non-oxidizing gas and a mixed gas thereof, but an oxidizing gas and a mixture thereof may be used.

Further, the speed at which the plasma flame radiation torch 4 moves on the rail 3 in synchronization with the steel plate 1 is preferably 0.1 to 200 m / min, while the moving speed of the plasma flame radiation torch 4 in the direction transverse to the rolling direction of the steel plate 1 is A range of 1 to 400 cm / s is suitable.

The movement of the plasma flame radiation torch 4 will be described below with reference to FIG. 2 which is a left side view of FIG. In addition, in FIG. 2, since the torches 4 overlap each other,
Illustration of overlapping portions is omitted.

That is, the plasma flame radiation torch 4 rotates the ball screw 10 by a driving motor (not shown),
By fixing it to the moving bearing 5 that moves with the rotation, the steel sheet 1 can be moved in a direction orthogonal to the rolling direction. A support shaft 9 is provided on each moving bearing 5 so that the moving bearing 5 does not operate in the same manner as the rotation of the ball screw 10. Also in this case, the support shaft 9 overlapping the ball screw 10 is not shown in FIG.

To move the plasma flame radiation torch 4 along the rail 3, the driving force of the motor 7 is transmitted to the wheels 6,
The wheels 6 may run on the rails 3. That is,
The wheels 6 attached to both ends of the ball screw 10 are
The wheels 6 are locked so as not to come off, and each wheel 6 transmits a driving force from the motor 7, for example, a drive shaft 7a of the motor 7.
A chain that interlocks with the rail 3 is arranged along the rail 3, and each wheel 6 is guided and moved by this chain, or a mechanism that transmits the driving force of the motor 7 by gears instead of the chain is used on the rail 3. The torch 4 can be moved by moving the.

When the torch 4 at the head of the plasma flame radiation torch group reaches the end of the rail 3, the polarity of the motor 7 is switched to quickly return the plasma flame radiation torch group 4 to the start position. Since plasma flame radiation is not performed on the steel plate 1 during this returning, there may be a case where the plasma flame radiation is not applied to the steel plate 1. Further, since there is a limit to downsizing the plasma flame radiation torch itself, it may be difficult to keep the radiation interval of the plasma flame within a suitable range (2 to 30 mm). Therefore, in order to carry out the plasma flame radiation, it is also possible to install a plurality of the devices shown in FIG. 1 as shown in FIG.

(Operation) Plasma flame was radiated at an output current of 10 A by the apparatus of FIG. 1 equipped with a torch having a nozzle hole diameter of 0.15 mm on a 0.23 mm thick grain-oriented silicon steel sheet subjected to final finish annealing.

Argon was used as a gas, and the radiation was linearly emitted in a direction substantially orthogonal to the rolling direction of the steel sheet with an interval of 8 mm in the rolling direction.

Also, the speed of movement in synchronization with the steel plate of the torch is 50 m / min,
The moving speed of the steel sheet in the direction orthogonal to the rolling direction is 250 mm / s.
And

The magnetic characteristics of the plasma flame radiating portion of the steel plate after the plasma flame radiating and the portion where the plasma flame radiating was not taken, which was sampled from the position near the radiating portion, were examined. The results are shown in Table 1.

From Table 1, it can be seen that the iron loss is remarkably improved in the portion subjected to plasma flame radiation.

(Effects of the Invention) By using the apparatus of the present invention, it is possible to continuously emit plasma flame to the surface of grain-oriented silicon steel sheet and obtain a grain-oriented silicon steel sheet with low iron loss without inhibiting production efficiency. Therefore, the production of grain-oriented silicon steel sheet with low iron loss on an industrial scale can be advantageously realized.

[Brief description of drawings]

 FIG. 1 is an explanatory diagram of an iron loss improving device, FIG. 2 is a left side view of FIG. 1, and FIG. 3 is an explanatory diagram when a plurality of units are installed. 1 ... Directional silicon steel plate 2 ... Rotating drum 4 ... Plasma flame radiation torch

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Atsuto Honda Atsushi Kawasaki-cho, Chiba-shi, Chiba Kawasaki Steel Co., Ltd.

Claims (1)

[Claims] 1. A rotary drum for guiding the running of a finish-annealed grain-oriented silicon steel sheet in the rolling direction, and a rotary drum which moves on a concentric circle with the grain-oriented silicon steel sheet traveling on the rotary drum. An iron loss improving device for a grain-oriented silicon steel sheet, comprising: a plasma flame radiation torch that moves in a direction transverse to the rolling direction of the grain-oriented silicon steel sheet.