JPS6237368A - Iron loss decreasing device for grain oriented silicon steel sheet - Google Patents

Abstract

PURPOSE:To considerably decrease the iron loss of a grain oriented silicon steel sheet by subjecting both surfaces of the grain oriented silicon steel sheet from which the oxide on the surfaces is removed after finish annealing and which is further subjected to mirror finishing to vapor deposition of the nitride, carbide and oxide of specific metals by an ion plating method. CONSTITUTION:A coil 7 of the grain oriented silicon steel sheet from which the oxide on the surfaces is removed after finish annealing and of which the surfaces are further subjected to mirror finishing is put through a preliminary low vacuum vessel 2 into a high vacuum ion plating treatment device 1. The coil 8 is un-coiled therein and is repeatedly passed by guide rolls 13 in said device. Two vapor deposition sources 11, 12 and two ionization electrodes 12, 12 are used and gas such as N2, CH4, O2 or NH3 is introduced into the device. The nitride or carbide of Ti, Zr, V and other metals evaporated from both sources 11, 11 is deposited by evaporation on the steel sheet and further the oxide of Al, Ni, Cu and other metals is deposited thereon by evaporation. The sheet is coiled 9 and the coil is taken out through a preliminary low vacuum vessel 3, by which the coil 10 of the grain oriented silicon steel sheet having the low iron loss is obtd.

Description

Detailed Description of the Invention (Industrial Field of Application) This invention provides a method for obtaining an ultra-low iron loss grain-oriented silicon steel plate by forming an ultra-thin tensile coating on the plate surface by ion plating. This paper attempts to propose an iron loss reduction device for silicon steel sheets.

Remarkable development efforts have been made in recent years to improve the electrical and magnetic properties of unidirectional silicon steel sheets, particularly in order to meet the extreme demands of reducing iron loss, and these efforts are beginning to bear fruit. However, a serious problem associated with the implementation of this method is that when so-called strain relief annealing is performed after processing and assembly when using unidirectional silicon steel sheets, characteristic deterioration inevitably occurs, making it difficult to use the unidirectional silicon steel sheets. It is pointed out that the disadvantage is that it is subject to restrictions.

This specification describes the development of a new iron loss reduction device for grain-oriented silicon steel sheets that can advantageously satisfy the above requirements regardless of whether or not the steel sheet undergoes a high-temperature thermal history such as strain relief annealing.

By the way, as is well known, unidirectional silicon steel sheets
The product's secondary recrystallized grains are accumulated in the (110) I:001), or Goss, orientation.It is mainly used as the iron core of transformers and other electrical equipment, and has the electrical and magnetic characteristics of the product. It is required to have a high magnetic flux density (represented by the Boo value) and a low iron loss (represented by the L77so value).

This unidirectional silicon steel plate is manufactured through a wide variety of complicated processes, and has resulted in numerous inventions to date.

Improvements have been made, and today the magnetic properties of products with a plate thickness of 0.30ff1m are B, o 1.90T or more, WB7so 1
．． 05w/Kg or less, and the magnetic properties of products with a plate thickness of 0.23mm are B, o L, 89T or more, Jtzso 0.9
The production of unidirectional silicon steel sheets with low core loss of about 0 W/Kg or less has become almost common.

Particularly recently, there has been a marked increase in demand for power loss reduction features from an energy-saving perspective, and in Europe and the United States, when creating a transformer with low loss, the reduction in iron loss is converted into a monetary value and added to the transformer price.・The "evaluation" (iron loss evaluation) system has become widespread, and this is nothing but a demand for ultra-low iron loss that has already been mentioned.

(Prior art) It has been proposed that after final annealing of a unidirectional silicon steel sheet, laser irradiation is applied to the surface of the steel sheet in a direction approximately perpendicular to the rolling direction to introduce local minute strain to subdivide the magnetic domains, thereby reducing iron loss. (Special Publication No. 57-2252.

(Refer to Japanese Patent Publication No. 57-53419, Japanese Patent Publication No. 58-26405, and Japanese Patent Publication No. 58-26406) However, this magnetic domain refining technology is effective as a core-oriented transformer material without strain relief annealing. In the case of wound iron transformer materials, which are subjected to strain relief annealing, the local minute strain introduced by laser irradiation is released by annealing and the magnetic domain width becomes wider, so the laser irradiation effect is lost. .

On the other hand, in the low core loss range due to the formation of an ultra-thin tension coating by ion plating, it is not affected by high temperature thermal history such as strain relief annealing.

The development of an apparatus for reducing iron loss of grain-oriented silicon steel sheets by forming such an ultra-thin tension coating is unique to this invention, and no conventional technical literature can be referred to.

(Problems to be Solved by the Invention) Recently, the inventors have succeeded in manufacturing an ultra-low iron loss unidirectional silicon steel sheet that does not suffer from the deterioration of characteristics due to the above-mentioned high-temperature treatment. That is, in this manufacturing method, after removing oxides on the surface of a grain-oriented silicon steel sheet that has been finish annealed, it is polished to a mirror-like state, and then Ti, Zr,
V, Nb, Ta, Cr, ! Jo, W, M
n, Co.

Forming an ultra-thin tensile coating consisting of at least one selected from nitrides and/or carbides of Ni, An, B, Si, and oxides of AF, Ni, Cu, W, Si, and Zn. We discovered that this makes it possible to reduce iron loss in unidirectional silicon steel sheets.

In order to carry out the above method, this invention applies ion plating to both sides of a coiled steel sheet that has been subjected to chemical polishing or electrolytic polishing to a mirror-like state after removing oxides on the surface of a grain-oriented silicon steel sheet that has been finish annealed. It is an important object to provide an iron loss reduction device for grain-oriented silicon steel sheets in which the ultra-thin tensile coating of carbides and/or nitrides or oxides described above is continuously formed. (Means for Solving the Problems) This invention involves high-vacuum ion plating of a coil that has been wound after undergoing a final annealing process according to the conventional method for grain-oriented silicon steel sheets, removing oxides from the surface of the sheet, and polishing it to a mirror finish. This is a device that forms an ultra-thin tension coating on both sides of the coil during unwinding and rewinding in a processing tank, and the processing tank is equipped with a preliminary vacuum that can reduce the pressure to near the internal vacuum level of the tank. A loading and unloading chamber for the above-mentioned coils, which consists of a tank, is attached, and a sheet passing guide roll is provided to guide the coils, which are loaded from this loading chamber into the processing tank, to turn them upside down. This is an iron loss reduction device for a grain-oriented silicon steel plate, which is characterized by having two sets of evaporation sources and ionization electrodes facing the bottom surface of the grain-oriented silicon steel plate.

FIG. 1 schematically shows an example of an iron loss reduction device for a mirror-finished grain-oriented silicon steel coil. In the figure, 1 is a high vacuum ion plating processing device, 2 is a preliminary low vacuum chamber for mirror-finished coils, 3 is a preliminary low vacuum chamber for coils after ion plating, 4 is a preliminary low vacuum exhaust port, 5 is a high vacuum exhaust port, 6 is a gas inlet port, 7 is a mirror-finished Koinobe 8 is a coil before ion plating, 9 is an ion plated Koinobe 10 is a preliminary low vacuum chamber that has been ion plated. 11 is the evaporation source.

12 indicates an ionization electrode.

(Function) Next, the mirror-finished coil 7 is subjected to continuous ion plating in the following order.

First, after removing surface oxides from the finish-annealed unidirectional silicon steel sheet, the coil 7, which has been finished to a mirror-like state by chemical polishing or electrolytic polishing, is placed in the preliminary low vacuum tank 2 shown in Fig. 1 as indicated by the arrow. .

After evacuating the preliminary low vacuum tank 2 to a vacuum level of 10-2 to 10-3) by using a vacuum pump through the preliminary vacuum exhaust port 4, the coil is subjected to high-vacuum ion plating as shown by the arrow. The coil 8 before ion plating is unwound and wound around the threading guide roll 13 in the high vacuum ion plating processing equipment 1 for threading. The inside of this high-vacuum ion plating processing apparatus 1 is evacuated to a high vacuum of 10-4 to 10-6 torr by a vacuum pump connected to a high-vacuum exhaust port 5.

After that, the mirror-finished steel plate is passed in the direction of the arrow, and ion plating is applied during that time.

In ion plating, after evaporating the molten metal in the evaporation source 11, a small amount of gas is introduced from the gas inlet 6 and ionized by the ionization electrode to form a thin film on both surfaces of the steel plate.

In order to apply continuous ion plating treatment to both the front and back surfaces of a steel plate to form a thin film coating, as shown in the diagram, the plate is threaded in a parallel horizontal direction by a group of threading rolls 13 in two stages. Although the ion plating process is performed, the two sets of evaporation sources and ion electrodes are not limited to the upper and lower two stages.

Any conventionally known method such as electron beam, hollow cathode, or electrode heating may be used to melt the metal in the evaporation source 11, and in order to form a film in a short time, a magnetic field may be applied directly below the surface of the steel sheet being threaded. A two-gnetron device that accelerates ions may also be used.

The steel plate that has been subjected to ion plating is wound into a coil 9, then moved to a preliminary low vacuum tank 10 as shown by the arrow, and then taken out of the system.

(Effect of the invention) Such continuous ion plating makes it possible to effectively form an ultra-thin tensile film of carbides and/or nitrides or oxides on the surface of the steel sheet. It is possible to reduce iron loss in steel plates.

This device can be used to apply a ceramic thin film coating to both surfaces of low-carbon cold-rolled steel sheets, stainless steel sheets, and other general steel sheets.

(Example) After removing oxides on the surface of a unidirectional silicon steel plate (0.23 mm thick) using a finishing annealing machine and pickling, the surface of the steel plate was made into a mirror-like state by electrolytic polishing. 0.5 m/min at a speed of 15 m/min on both surfaces of the steel plate coil, which was made into a mirror-like state of approximately 7 tons using a heating device.
A ˜0.6 μm thick TiN tension coating was continuously formed. The magnetic properties of the product at that time were as follows.

B+o=1.92T, W+7zso=0.72W/K
g

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a continuous ion plating apparatus according to the present invention. 1... High vacuum ion plating processing equipment 2.3.
・・Preliminary vacuum chamber (loading chamber, loading chamber) 11 ・・Evaporation source
12... Ionization electrode 13... Threading guide roll

Claims (1)

[Claims] 1. A coil that has undergone a final annealing process according to the conventional method for grain-oriented silicon steel sheets, has been subjected to oxide removal and mirror polishing treatment on the plate surface, and is wound up in a high-vacuum ion plating treatment tank. An apparatus for forming an ultra-thin tension coating on both sides of the coil during unwinding and rewinding, the coil comprising a preliminary vacuum tank in the processing tank that can reduce the pressure to near the internal vacuum level of the tank. A loading/unloading room is attached, and a threading guide roll is provided to guide the coils loaded into the treatment tank from this loading room, so that the coils are reversed inside out. A device for reducing iron loss of grain-oriented silicon steel plate, characterized by comprising two sets of evaporation sources and ionization electrodes.