JPS61186420A - Production of oriented electrical steel sheet having extremely low iron loss - Google Patents

Abstract

PURPOSE:To obtain the titled steel sheet having an extremely low iron loss and good magnetic flux density by removing the surface film of the oriented electrical steel sheet subjected to finish annealing, plating Sb onto the surface to a specific coating weight to form different penetrating bodies at intervals and segmenting finely magnetic domains. CONSTITUTION:The surface film such as glass film and insulting film of the oriented electrical steel sheet subjected to the finish annealing is removed by the irradiation of laser light, etc. thereon to expose the base iron of the steel sheet. The steel sheet is then plated to >=0.95g/m<2> coating weight by partial plating such as electroplating using 1 or >=2 kinds among Sb, Sb alloy, Sb compd. and Sb mixture. The penetrating bodies contg. Sb different from the steel components or steel compsn. as the steel components or steel compsn of the steel sheet are thereby formed at intervals to the surface and since the germs of the magnetic domains are generated on both sides of the penetrating bodies, the effect of improving the iron loss owing to the segmentation of the magnetic domains is not lost even if the steel sheet is subjected to a heat treatment such as strain relief annealing, by which the oriented electrical steel sheet having the extremely low iron loss and excellent magnetic characteristics is stably produced.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for producing grain-oriented electrical steel sheets with extremely excellent magnetic properties, and more specifically, the present invention relates to a method for producing grain-oriented electrical steel sheets with extremely excellent magnetic properties, and more specifically, the present invention relates to a method for producing grain-oriented electrical steel sheets with extremely excellent magnetic properties. The present invention relates to a method for manufacturing grain-oriented electrical steel sheets that have extremely low core loss and good magnetic flux density.

[Conventional technology]

Grain-oriented electrical steel sheets are mainly used as iron core materials for transformers and other electrical equipment, so they need to have good excitation characteristics and iron loss characteristics.

This steel plate utilizes the secondary recrystallization phenomenon and has a rolling surface of (110
) plane has a <001> axis in the rolling direction, that is, secondary recrystallized grains having a so-called Goss orientation are developed.

By increasing the degree of accumulation of the (110) <001> orientation and reducing deviation from the rolling direction as much as possible, products with excellent excitation characteristics, iron loss characteristics, etc. are being manufactured. .

By the way, as the degree of integration of the (110) <001> orientation increases, the crystal grains become larger, and since the domain wall penetrates the grain boundary, the magnetic domain becomes larger, so there is a phenomenon in which iron loss does not decrease as the degree of integration increases. There is.

For example, Japanese Patent Publication No. 58-5968 discloses a technique for eliminating the above-mentioned phenomenon and reducing iron loss. This is done by pressing small balls etc. onto the surface of the final finish fired pure unidirectional electromagnetic steel sheet to form dents with a depth of 5μ or less and applying linear minute strain to subdivide the magnetic domains. It is intended to improve losses. Furthermore, Japanese Patent Publication No. 58-26410 discloses that at least one trace of laser irradiation is formed on the surface of each crystal grain of secondary recrystallization generated by final finish annealing to subdivide the magnetic domain and reduce iron loss. is proposed.

These Special Publications No. 58-5968 and Special Publication No. 58-2
According to the method disclosed in No. 6410, it is possible to apply local minute strain to the surface of a unidirectional electric F11 steel sheet, improve iron loss, and obtain an ultra-low iron loss material.

[Problem that the invention seeks to solve]

However, when the ultra-low iron loss material obtained as described above is annealed, the iron loss improving effect is lost, and for example, there is a problem that the iron loss improving effect is lost in strain relief annealing when manufacturing a wound core.

The present invention efficiently performs magnetic domain refining that does not lose its iron loss improvement effect even after heat treatment, such as strain relief annealing, to produce grain-oriented electrical steel sheets with extremely low iron loss and excellent magnetic properties in a stable and productive manner. For purposes of manufacturing methods.

The present inventors performed strain relief annealing after magnetic domain refining, for example, at 700°C.
Many experiments were conducted to produce T11m plates with extremely low iron loss and excellent magnetic properties through efficient magnetic domain refining, which does not lose its iron loss improvement effect even when heat treated at temperatures of ~900℃. did.

[Means for solving problems]

As a result, in the finish annealed grain-oriented electronic steel sheet, Sb,
, Sb gold alloy, Sb compound, Sb mixture, and Sb that is different from the steel composition or steel structure of the steel sheet.
When an interstitial body containing an intruder, such as an alloy layer, surface reaction product, or diffused material resulting from a reaction with a steel plate or a surface coating, is formed by entering the steel plate at intervals, magnetic domain buds are formed on both sides of the intruder. When the steel sheet is magnetized, the magnetic domains are subdivided, and even if heat treatment such as stress relief annealing is performed afterwards, the iron loss improvement effect of magnetic domain subdivision does not disappear, resulting in extremely low iron loss and excellent magnetic properties. It was discovered that magnetic steel sheets can be stably produced.

The present invention was made based on this knowledge, and its characteristics are that surface coatings such as glass coatings and insulation coatings of finish annealed grain-oriented electrical steel sheets are removed at intervals or entirely; Next, the steel plate was coated with Sb, , Sb
Plating is performed using one or more of gold alloy, Sb mixture, or Sb compound to a basis weight of 0.05 g/rrf or more, and Sb-containing intruders that are different from the steel composition or structure are separated at intervals. The present invention provides a method for manufacturing a grain-oriented electrical steel sheet with extremely low core loss, which is formed by forming magnetic domains and refining the magnetic domains. Furthermore, the present invention is characterized in that, subsequent to the plating, an insulating coating treatment or a heat treatment is performed.

In the present invention, "intruders" refer to Sb, Sb gold alloys, Sb mixtures, and Sb compounds that form grains, lumps, or lines in steel sheets, either alone or in combination with steel sheets, etc. It expresses the state of existence.

Heat-resistant magnetic domain refining according to the present invention can be performed as follows. That is, surface coatings such as glass coatings, oxide coatings, and insulation coatings formed on finish-annealed grain-oriented electrical steel sheets are removed by laser irradiation, grinding, cutting, solvent, chemical polishing, pickling, corrosion, shot blasting, etc. The steel plate substrate is exposed by removing it at intervals or entirely, and then applying one or more of Sb, Sb gold alloy, Sb mixture, and Sb compound to the steel plate to form the surface coating. 0.05g/rrf is removed by plating such as electroplating, hot-dip plating, or vacuum plating if it is removed at intervals, or by partial plating such as partial electroplating if it is completely removed. When plated with the above basis weight, Sb-containing intruders are stably and efficiently spread over the steel plate at intervals, and heat-resistant magnetic domains are subdivided.

That is, during plating, the surface coating such as the glass coating or the insulating coating is applied to the steel sheet base and the aforementioned Sb, Sb gold alloy, Sb, Sb gold alloy, Sb, etc.
B mixture inhibits the reaction with the Sb compound, while the reaction occurs intensively or selectively at the exposed parts of the steel plate after the surface coating is removed, and the intruder stabilizes as it enters the steel plate. It is formed by Furthermore, even when partial plating is performed when the surface coating has been completely removed, penetrants are similarly stably formed.

, Sb subdivides the magnetic domains of the steel sheet and significantly reduces iron loss. Further, the iron loss reducing effect of magnetic domain refining does not disappear even after strain relief annealing at a high temperature, for example, 700 to 1000° C., which is an extremely excellent effect. It also has good magnetic flux density, and the amount and depth of the intruders can be changed by changing the coating weight of the plating, making it possible to create different iron loss characteristics and magnetic flux density characteristics. For example, by increasing the coating weight of plating, it is possible to reduce iron loss and lower magnetic flux density, making it possible to produce a grain-oriented electrical steel sheet with extremely excellent actual iron loss. Next, if necessary, add phosphoric acid, aluminum phosphate, magnesium phosphate, etc. to the 1ssi plate.
Apply an insulating coating liquid containing one or more of phosphates such as zinc phosphate and calcium phosphate, chromic acid, chromates such as magnesium chromate, dichromate, and colloidal silica. For baking at a temperature of 350° C. or higher, insulation coating treatment is performed, or heat treatment is performed after plating.

The intruder is protected or strengthened by the insulating coating treatment or heat treatment, and is prevented from peeling off even if frictional force, slipping force, etc. are subsequently applied during coil winding.

The present invention will be specifically explained below based on an example in which a finish annealed grain-oriented electrical steel sheet is electroplated.

In the present invention, the finish annealed grain-oriented electrical steel sheet is subjected to magnetic domain refining, but the steel composition of the grain-oriented electrical steel sheet and the manufacturing conditions until finish annealing do not need to be specified; for example, AIN is used as an inhibitor.

MnS, MnSe, BN + Cu zS, etc. are used as appropriate, and if necessary, Cu, Sn, Ci,
Contains elements such as Ni, Mo, and Sb, and further hot-rolls the slab, anneales it, and cold-rolls it once or twice or more with annealing in between to obtain the final plate thickness, and decarburizes it.
There is no need to specify the conditions for a series of processes in which the annealing separator is applied and finish annealing is performed.

By the way, the finish annealed directional electrolyte steel sheet has an oxide film containing Sing formed in the decarburization annealing process in the previous step and an MgO film.
A glass coating (
forsterite film) is formed. The glass film and oxide film impair electrical conductivity during plating, and may cause damage to the steel plate base metal.
Inhibits Sb reaction.

Further, if an insulating coating liquid such as phosphoric acid, aluminum phosphate, magmium phosphate, chromate, or colloidal silica is applied to the steel plate and an insulating coating is formed by baking, the insulating coating can prevent plating reactions.

Therefore, in this application, surface coatings such as glass coatings, insulation coatings, etc. are removed at intervals. This removal can be done by laser irradiation, grinding, cutting, ballpoint pen, marking, etc.
This is done at 0m intervals. The direction of the removal is preferably 30 to 90 degrees with respect to the rolling direction of the steel plate. Moreover, the width of removal is preferably 0.01 to 5 fl. By removing the surface coating, the steel plate base metal is exposed, and a portion of the steel plate base metal is partially strained. This exposure also includes forming a slight dent in a part of the steel sheet base.

Next, the steel plate is made of Sb alone, 5b-Sn, 5
b-Zn.

5b-Pb, Sb-Bt, 5b-5n-Zn
, Sb-gold alloys such as 5b-Co, 5b-Ni,
Sb and Sn, Zn, Pb, Bi, Co
, Ni, ^1, etc., or a mixture with two or more of them, Sb oxide, sulfate, phosphate, etc., are passed through an electrolytic solution to which Sb compounds are added, and electroplated. . During this plating, an electrical reaction occurs only at the locations where the surface coating is removed at intervals and the steel sheet base is exposed, and no such reaction occurs at other locations. Therefore,
Sb, Sb gold alloy, Sb mixture, etc. are plated only on the exposed portions of the steel sheet base. Therefore, Sb-containing intruders such as alloy layers and diffused substances can be formed at desired locations and at desired intervals without reducing the sheet passing speed of the plating line at all. Furthermore, since the portion where the surface coating is present does not react with the electrolyte as described above, the surface coating also has the effect of being maintained in a clean state. In this plating, the basis weight is important, and if the amount is small, there will be few intruders formed and the magnetic domain will not be refined.To perform the magnetic domain refinement that reduces iron loss characteristics, 0.05g/rd is required. A coating weight above the above is required, and if the coating is applied above the coating weight, an alloy layer, diffused substances, and other penetrating bodies different from the steel plate composition or structure will be formed on the steel sheet, and the heat-resistant magnetic domains will be subdivided. . Further, if necessary, it is applied to an insulating coating liquid and baked at a temperature of 350° C. or higher to form an insulating coating. Or heat treat.

FIG. 1 shows a micrograph (X100O) of an example of an intruder formed in a steel plate by applying the present invention.

It is inferred that the structure of the intruder is different from the steel composition, and the structure is also different, so many magnetic domain buds are formed on both sides of the intruder, and when the steel plate is magnetized, the magnetic domain buds extend and the magnetic domains are subdivided. be done.

Examples will be described below.

Example 1 C: 0.075, Si: 3.22 in weight%
, Mn: 0.06B.

Al: 0.030, S: 0.024, C
A silicon steel slab consisting of u: 0.08, Sn: 0.10, and the balance iron was hot rolled and annealed by a well-known method.
A steel plate with a thickness of 0.2251 m was obtained through cold rolling.

Next, the well-known decarburization annealing process of applying an annealing separation side mainly composed of MgO and final finish annealing was performed. Thereafter, an insulating coating liquid was applied, and an insulating coating was formed by baking which also served as flattening annealing. This was used as the "before treatment" test material.

The steel plate was irradiated with a C(h) laser to remove the surface coating at 5fi intervals in a direction perpendicular to the rolling direction, and then treated with an electrolytic solution containing Sb shown in Table 1, with a basis weight of 0.1,
1.10. The sample material was electroplated to give a ``treated'' test material of g/m2. Thereafter, strain relief annealing was performed at 800° C. for 4 hours to obtain a “strain relief annealed” test material.

As described above, the magnetic properties of each sample material were measured ``before treatment'', ``after treatment'', and ``after strain relief annealing''.

The measurement results are shown in Table 2.

As is clear from the Examples shown in Table 1 and above, even when subjected to strain relief annealing after magnetic domain refining, the iron loss improving effect is not lost, and a grain-oriented electrical steel sheet with extremely low iron loss and good magnetic flux density is provided.

〔Effect of the invention〕

As explained above, according to the present invention, the core loss of the steel plate is reduced by magnetic domain refining by the intruder, and after that,
It has an excellent feature not seen in previous magnetic domain refining methods, in that the iron loss improvement effect does not disappear even when strain relief annealing is performed at high temperatures.

[Brief explanation of drawings]

FIG. 1 is a metal micrograph (X 1000) showing an intruder formed in a steel plate according to the present invention. ? ri9 1 Iv+4t gu: no t 棧7mon

Claims (1)

[Claims] 1. Surface coatings such as glass coating and insulation coating of a finish annealed grain-oriented electrical steel sheet are removed, and the steel plate is coated with Sb, Sb alloy,
Magnetic domain refining is achieved by plating with one or more types of Sb compounds and Sb mixtures to a basis weight of 0.05 g/m^2 or more to form intruders different from the steel composition or steel structure at intervals. A method for producing a grain-oriented electrical steel sheet with extremely low iron loss. 2. Surface coatings such as glass coating and insulation coating of finish annealed grain-oriented electrical steel sheet are removed at intervals, and Sb is added to the steel plate.
, Sb alloy, Sb compound, or Sb mixture is used to plate the steel to a basis weight of 0.05 g/m^2 or more to form intruders different from the steel composition or steel structure at intervals. A method for producing grain-oriented electrical steel sheets with extremely low core loss, which comprises refining magnetic domains and then subjecting them to insulation coating treatment or heat treatment.