JPH03249132A - Iron loss improving device for grain oriented silicon steel sheet - Google Patents

Abstract

PURPOSE:To drastically decrease the iron loss of a grain oriented silicon steel sheet by a simple method by radiating a plasma frame to the surface of the grain oriented silicon steel sheet subjected to finish annealing. CONSTITUTION:The grain oriented silicon steel sheet 1 subjected to the finish annealing is wound around a rotary drum 2 via deflector rolls 7 and is intermittently transported by an intermittent driving system 4. Plural pieces of equidistantly spaced plasma flame radiating torches 3 are disposed along the circumference of the rotary drum 2 apart a specified spacing above the steel sheet 1 wound around the rotary drum 2 and the Ar plasma frames are radiated from these torches to the surface of the steel sheet 1. The torches 3 are mounted to a slider a movable along the revolving shaft of the rotary drum 2 in this case and while the slider S is moved in the axial direction of the drum 2, the plasma frames are radiated. The entire surface in the transverse direction of the steel sheet 1 is thus subjected easily to the plasma frame radiation treatment. The iron loss of the silicon steel sheet 1 is thereby easily decreased.

Description

[Detailed Description of the Invention] (Industrial Application Field) Regarding the reduction of iron loss in grain-oriented silicon steel sheets used in transformers, this specification particularly describes an iron loss improvement device that applies plasma flame radiation. Describe the development results.

(Prior art) The iron loss of grain-oriented silicon steel sheets is mainly the thermal energy loss that occurs when they are used in the core of transformers. The demand for low iron loss is increasing.

Regarding the low iron loss range of silicon steel sheets, the crystal orientation of the steel sheet is (1
10) In recent years, various efforts have been made to align the steel plate with a high degree of alignment in the <001> orientation, increase the electrical resistance of the steel plate by increasing the Si content, reduce and avoid impurities in the steel plate, and in recent years, reduce the thickness of the steel plate. Although many attempts have been made, the reduction of iron loss by such metallurgical methods has currently reached its limit.

As an attempt to reduce the iron loss of silicon steel sheets using methods other than metallurgical methods, the Japanese Patent Publication Publication No. 57, which irradiated the surface of silicon steel sheets with a laser,
A technique disclosed in Japanese Patent Publication No. 2252 is known, but with this method, an increase in the cost of the equipment used therein can be avoided, and furthermore, an increase in initial cost and running cost due to the short life of the laser excitation lamp can be avoided. Unavoidable. Furthermore, since the lasers used are often not visible light, there remain problems in terms of safety measures.

Another attempt to reduce iron loss in silicon steel sheets using methods other than metallurgical methods is to install multiple plasma torches on the silicon steel sheet conveyance line and emit plasma from the torches while synchronizing the movement of the steel sheets. There is also an attempt to
2-151512, JP-A-62-151513, and JP-A-62-151519).

However, in this method, the piping attached to the plasma torch must be bundled and rotated in synchronization with the rotating drum, making the apparatus itself large-scale.Moreover, the width of the silicon steel plate to be processed becomes wider, and its conveyance speed increases. It cannot be applied under these conditions.

(Problem to be solved by the invention) It is possible to more advantageously achieve a significant reduction in iron loss without causing the above-mentioned problems that occur when reducing iron loss in silicon steel sheets using methods other than metallurgical methods. It is an object of this invention to propose a new device.

(Means for Solving the Problems) The present invention is an apparatus for emitting plasma flame onto the surface of a grain-oriented silicon steel plate that has been finish annealed, which comprises: a rotating drum that guides the winding of the grain-oriented silicon steel plate; At least one plasma flame emitting torch disposed toward the surface of the grain-oriented silicon steel plate wrapped around the rotating drum and movable along the rotation axis of the rotating drum; and the grain-oriented silicon steel plate wrapped around the rotating drum. This is an iron loss improving device for grain-oriented silicon steel sheets, characterized by comprising an intermittent drive system that intermittently feeds iron.

Now, FIG. 1 shows an iron loss improvement device for grain-oriented silicon steel sheets according to the present invention, in which the number 1 is a grain-oriented silicon steel sheet that has been finish annealed, and the number 2 is a steel plate 1 that is used during the conveyance process of the silicon steel sheet l. A rotating drum 3 serves as a winding guide, and a plurality of plasma flame emitting torches 3 are arranged at equal intervals along the circumference of the rotating drum 2, and the torches 3 are movable along the rotation axis of the rotating drum 2. It is fixedly held on a slider S and placed on the surface of a grain-oriented silicon steel plate 1 wound around a rotating drum 2 with an extremely small distance therebetween. Moreover, 4 is an intermittent drive system that feeds the silicon steel plate 1 intermittently, and as a specific means of this intermittent drive system 4, for example, a priddle roll is installed.

In addition to being useful as an intermittent drive system, the priddle roll 4 is also suitable for the rotating drum 2 in order to maintain a constant distance between the plasma flame emitting torch 3 and the silicon steel plate 1 when dealing with steel plates that have selvage or belly elongation. It plays the role of wrapping with a certain tension. In addition, the number 5 in the figure is a free looper on the dispensing side that serves to temporarily store the steel plate 1 as shown by the broken line in the figure when the rotating drum 2 is stopped during the conveyance process of the silicon steel plate 1. A free looper on the winding side, and a deflation crawler 7 for winding the silicon steel plate 1 around the rotating drum 2 at an appropriate angle.

(Function) It has already been reported in Japanese Unexamined Patent Publication No. 62-96617, etc. that the effect of significantly lowering iron loss can be obtained by radiating plasma flame onto the surface of a grain-oriented silicon steel sheet. In the invention, an annealed silicon steel plate 1 is wound around a rotating drum 2, and the synchronous rotation of the rotating drum 2 and the priddle rolls 4 provided before and after the rotating drum 2 results in an interval L() - number n of units x pitch interval! =L), and with the conveyance of the silicon steel plate 1 temporarily stopped, the slider S is moved along the axial direction of the rotating drum 2, and the slider S is moved along the width direction of the steel plate 1. Since the slider S holding the plasma flame emitting torch 3 does not need to be moved in accordance with the movement of the rotating drum 2, the device itself does not become large-scale, and the steel plate line Speed can be advantageously increased.

The installation interval of the plasma flame emitting torch 3 installed on the slider S is such that the plasma flame injection interval to the steel plate 1 is 2 to 3 times.
It is best to set it so that it is 0 mm, and the torch 3
The diameter of the aperture is 2.0 mm or less, and the output current is 1~
A range of 300A is advantageously suited.

Emission of plasma flame may be either non-transfer type or transfer type, but the non-transfer type is easier to emit.

Regarding the gas for plasma generation, Ar, Nl+H
Inert and non-oxidizing gases such as No. 2, and mixtures thereof are preferred, but oxidizing gases and mixtures thereof may also be used. Further, the moving speed of the plasma flame emitting torch 3 in the width direction of the steel plate 1, that is, the moving speed of the slider S, is preferably 100 to 2000 mm/S.

In this invention, the relationship among the line threading speed of the steel plate, the plate feeding speed of the rotating drum, the moving speed of the torch, etc. When the moving speed (including acceleration/deceleration) is (including acceleration and deceleration), the length of the torch head is L (=-board feed amount per cycle), the torch movement distance is 2, and the torch movement time is t, the board feeding time T = L/V Torch travel time t = l / v Time per cycle (T,) T s = T + t = L / V + f /
v Line speed of steel plate (unwinding and winding) V, = L/TS = L/ ((L/V) + (f/v)).

Here, the torch moving distance l is changed depending on the width of the silicon steel plate to be processed, and since the torch moving speed ■ has an optimum value, the line speed VL, that is, when trying to increase the processing amount, the plate feed speed V or the torch It is necessary to increase the head length. However, if the plate feeding speed (■) is increased too much, the stopping precision during intermittent conveyance will be impaired, and the torch head will need to be lengthened.In such a case, a device such as the one shown in Fig. It can also be applied.

(Example) A grain-oriented silicon steel plate having a thickness of 0.23 mm that has been subjected to final finish annealing is transported by applying a device as shown in Fig. 1 equipped with a torch with an opening of 0.3 wr at the tip. A plasma flame of argon gas was radiated at an output current of 50 A and a torch movement speed of 400 ma+/S so as to form a linear pattern at intervals of 10+ W along the longitudinal direction of the inner steel plate in the width direction of the steel plate. Samples were taken from the silicon steel plates that were produced, and the magnetic properties of those with and without plasma flame radiation were compared and investigated.

The results are shown in Table 1.

As a result, Table 1 Boo: Magnetic flux density Lqy at H=100OA/m
So: Iron loss at B = 1.7T, f = 50Hz As is clear from Table 1, it was confirmed that the iron loss of the steel plate treated using the apparatus according to the present invention was significantly improved. Ta.

(Effects of the invention) According to this invention, there is no need to accompany the movement of the silicon steel plate with the torch that controls the emission of plasma flame, so the equipment does not become large-scale, and the line speed of the copper plate is increased. It can fully contribute to improving productivity.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the configuration of a device according to the present invention, and FIG. 2 is a diagram showing another example of the device according to the present invention. 1... Grain-oriented silicon steel plate 2... Rotating drum 3...
Plasma flame radiation 4... Intermittent drive system 5.6... Freel-buff... Deflector roll S... Slider

Claims (1)

[Scope of Claims] 1. A device for emitting plasma flame onto the surface of a grain-oriented silicon steel plate that has been finish annealed, comprising: a rotating drum that guides the wrapping of the grain-oriented silicon steel plate; at least one plasma flame emitting torch that is disposed toward the surface of the grain-oriented silicon steel plate and is movable along the rotation axis of the rotating drum, and the grain-oriented silicon steel plate wrapped around the rotating drum is intermittently fed. An iron loss improvement device for grain-oriented silicon steel plate, comprising an intermittent drive system.