JPS61111509A - Ultra-low iron loss grain-oriented electrical steel sheet - Google Patents

Abstract

PURPOSE:To hold improvement effect for the iron loss irrespective of the application of annealing for removing distortion in a high temperature by making a particle or bulk penetrating body of materials different from steel constituents penetrate into a ground iron of the steel plate at the depth of 2mum or more at intervals and finely dividing the penetrating body into magnetic sections to lower the iron loss in a steel plate. CONSTITUTION:An oriented electromagnetic steel plate finished and annealed is applied with a penetrative body, for example, a metal, a non-metal, their mixture, their alloy, their oxide, a phospheric acid, a boric acid, a phosphate, a borate and the like and furthermore, agents of their mixtures and a film is coated by the degree f 0.1-50g/m using coating, plating, depositing, adhesion, solvent welding and the like. Before or after forming the coated film, a distortion is added thereto at intervals by an optical means such as laser irradiation or an mechanical means such a as roll with grooves. Next, when the distortion is heat treated in the temperature 500-1,200 deg.C, a reaction which the agents cause in the steel plate or the surface coated film is enhanced by the distortion when the temperature is raised or held. Consequently, a penetrating body having a steel constituent of ground iron of a steel configuration, that is, a configuration different from a secondary recrystalline particle texture having a Goss orientation penetrates into the steel plate in the depth of 2mum or more at intervals for formation thereof.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a grain-oriented electrical steel sheet with extremely low iron use, and further relates to an ultra-low iron loss grain-oriented electrical steel sheet that does not deteriorate in iron loss even after heat treatment, such as strain relief annealing. Regarding steel plates.

(Prior technology) Grain-oriented electrical steel sheets are mainly used in transformers and other electrical equipment.
``Since it is used as a k-core material, it needs to have good excitation characteristics and iron FM characteristics.

This grain-oriented electrical steel sheet utilizes the secondary recrystallization phenomenon and has a (110) plane on the rolled surface and a <001> axis in the rolling direction.
A secondary recrystallized grain structure having a so-called Goss orientation is developed. By increasing the degree of integration of the (110) <001> orientation and reducing deviation from the ζ rolling direction as much as possible, products with excellent excitation characteristics, iron loss characteristics, etc. can be 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 passes through the grain boundary by 1r, the magnetic domain becomes larger, and the iron loss does not decrease even though the orientation is increased. There is a phenomenon.

As a technique for eliminating this phenomenon and reducing iron loss, there is, for example, Japanese Patent Publication No. 58-5968. This is done by pressing small balls etc. onto the surface of the unidirectional electrical steel sheet after final finish annealing to form indentations with a depth of 5μ or less and applying linear microstrain to refine the magnetic domains and reduce iron loss. It is something that can be improved. Further, in Japanese Patent Publication No. 58-21i410, at least one mark is formed by laser irradiation on the surface of each crystal grain of secondary recrystallization generated by final finish annealing to subdivide the magnetic domain.

It has been proposed to reduce iron loss.

These Tokuko Showa No. 5Ft-5968 and Tokuko Showa No. 58
According to the method disclosed in No. 26410, iron loss is improved by applying local minute strain to the surface of a grain-oriented electrical steel sheet, and an ultra-low iron loss material can be obtained.

However, when the ultra-low iron loss material R4 obtained as described above is annealed, the improvement effect for iron is lost. For example, there is a problem that the iron loss improving effect disappears in strain relief annealing when manufacturing the S core.

In addition, it is also known that directional electricity can be used to reduce the iron 1-member content by reducing the crystal grains of steel sheets.
In No.-207115, the average crystal grain size is 1 to 6 grains.

It is also known to reduce iron loss by applying tension to a steel plate. This uses, for example, the difference in thermal expansion coefficient between an insulating coating and a steel plate to apply tension to the steel plate using the insulating coating, thereby lowering the steel...

A large reduction in the use of steel is not expected by making the crystal grains finer or applying tension.

The object of the present invention is to obtain an ultra-low core loss grain-oriented electrical steel sheet that has an unprecedentedly low core loss and does not deteriorate in core loss even after heat treatment, such as strain relief annealing.

The present inventors have found that the iron loss is extremely low due to the magnetic domain refining, and that the strain relief annealing after the magnetic domain refining is performed at a temperature of, for example, 700 to 900°C.
Many experiments were conducted to obtain ultra-low core loss grain-oriented electrical steel sheets that retain their core loss improvement effect even when heat treated at temperatures of .

(Means for solving the problem) As a result, the finish annealed grain-oriented electrical steel sheet has: (1) an alloy layer due to a reaction with an intruder different from the steel composition or steel structure of the steel sheet, such as a steel sheet or a surface coating; When surface reaction products, etc. are formed by penetrating the copper plate at intervals of 2 μm or more in depth, magnetic domain sprouts are generated on both sides of the copper plate, and when the steel plate is magnetized, the magnetic domains are subdivided, resulting in a large iron loss. It was discovered that the iron loss improving effect of magnetic domain refining does not disappear even when heat treatment such as strain relief annealing is subsequently performed, and grain-oriented electrical steel sheets with extremely low iron loss can be obtained.

That is, in the present invention, in a grain-oriented electrical steel sheet 2 that has been finish annealed, an intruder different from the steel composition or steel structure of the steel sheet is allowed to penetrate the steel sheet by 2 μm or more to subdivide the magnetic domains. There is a major feature in this point.

Further, the iron loss improving effect of magnetic domain refining based on the intervening body is heat resistant, and it is also characterized in that the iron loss does not deteriorate even if it is subsequently subjected to strain relief annealing.

The gist of the present invention is that in a finish annealed grain-oriented electrical steel sheet, intruders having a steel composition or structure different from the steel composition or structure of the base steel are deep at intervals in the base steel of the steel sheet. The super core loss grain-oriented electrical steel is characterized in that the magnetic domain is subdivided by penetrating by 2 μm or more.

In the present invention, the term "intruder" refers to a coating on a steel plate that forms grains or lumps in the steel plate, either alone or in combination with other components on the steel plate side, including other I-moulds, or atmospheric components. It expresses the state of existence. In the present invention, the term "coating" refers to all mechanical coating films formed on at least a portion of the steel plate, chemical adhesion such as plating, or adhesion, and coatings that partially have a reactive layer. It is a general term that includes all materials, and its thickness is not specified.

The present invention will be explained in detail below.

The finish annealed grain-oriented electrical steel sheet to which the present invention is applied is
There is no need to specify the steel composition and manufacturing conditions up to final annealing; for example, AβN, MnS as an inhibitor, etc.
+ MnSe, BN, etc. are used, and if necessary, elements such as Cu, Sn, Cr, Ni, Mo, Sb, etc. are used, and the slab is further hot-rolled and annealed once or annealed. There is also no need to specify the conditions of a series of processes in which the sheet is sandwiched and cold-rolled two or more times to obtain the final thickness, decarburized annealed, coated with an annealing separator, and finished annealed.

In this example, magnetic domain refining by the formation of intruders can be performed, for example, as follows. That is, intrusive objects such as metals, non-metals, and mixtures thereof, are added to the finish annealed grain-oriented electrical steel sheet.
Approximately 0.1 to 50 g/m of alloys, oxides, phosphoric acid, boric acid, phosphates, borates, etc., and mixtures thereof, by coating, plating, vapor deposition, adhesion, welding, etc.
Before or after forming the film, strain is applied at intervals by an optical means such as laser irradiation, or by a mechanical means such as a grooved roll, a ballpoint pen, or a scribe. When heat treated at a temperature of 500-1200°C,
When the temperature is raised or kept warm, the chemical is released into steel or surface waves. Due to the above-mentioned strain, an intruder having a steel composition or a steel structure, that is, a secondary recrystallized grain structure having a Goss orientation, is different from the secondary recrystallized grain structure having a Goss orientation. It is formed by penetrating the steel plate at intervals.

FIG. 2 shows an optical microscope photograph (Xl, 000) of an example of the invader. The object marked with the symbol A in the figure is an intruder, and it is recognized that it has entered the steel sheet base in a granular form.

In the present invention, the method for forming the penetrant is not limited to the above-mentioned method. For example, the penetrant is coated at intervals by coating on a finish-annealed grain-oriented electrical steel sheet, and then determined according to the type of the coating. A method is adopted in which heat treatment is performed according to the heating rate and retention temperature. In addition, examples of the drug that forms a film include A7! , Si+Ti, Sb, Sr+C
u, Sn, Zn, Fe, Ni+Cr + M n +
Metals such as S, B, nonmetals, mixtures thereof, oxides,
Alloys, phosphoric acid, boric acid, phosphates, borates, sulfates,
Nitrates, silicates, and mixtures thereof are used.

By the way, in the above-mentioned method, the conditions of heat treatment temperature and time were changed to create test materials with different penetration depths from the steel plate surface of the granular or lump-like intruders that entered the machine. The steel composition at the time of slab of the test material is] C: o, os ~ o, oa%, Si: 2
．． 95-3.35%, Mn: 0.04-0.12%, A
tt: 0.010-3.35%, S: 0, 02-0
．． 03%, N: 0.0060 to 0.0090%, and the steps from slab heating to final annealing were performed using known methods.

The final plate thickness is 0.225 m.

Regarding this test material, iron tM after final annealing and formation of interstitial bodies
Wttyso was measured, and the iron loss improvement rate ΔW due to the formation of the interstitial body was determined from the values using the following formula.

ΔW=(W'+?1511 W"+7150/W'+
? 156)X100(%) However, W'+7/S. = Iron loss W+7/S after final annealing.

W217/, 11-Fe FMW+ after intruder formation? is.

The influence of the penetration depth of the intruder from the surface of the steel plate substrate on this iron loss improvement rate ΔW was investigated, and the results are shown in FIG. As can be seen in this figure, it was found that the improvement in II-tFi brought about by the formation of the intruder occurs when the penetration depth is 2 μm or more, and that as the depth increases, the FII11 deformation becomes larger. In this example, the penetration depth is 100μ.
The effect is saturated at about m. Such an effect is caused by the steel composition used for the test material (not limited to those containing carbon,
u, Sn, Sb, Mo.

It can also be used to contain one or more elements such as Cr and Ni. Therefore, in the present invention, the penetration depth of the intruder into the batten is set to 2 μm or more. There is no need to specify the upper limit of the depth, and it is determined by considering the thickness of the steel plate. Further, the interval between the intruders is, for example, about 1 to 30 cm, but there is no need to specify it in particular. Note that when the intruders are formed at narrow intervals, the granular or lump-like intruders are observed almost continuously.

Examples will be described below.

Example weight %: C: 0.077, Si: 3.30, M
n: 0.076, Al: 0.028, S
: 0.024, Cu: 0.16, Sn: 0
．． A silicon steel slab consisting of 12% iron was hot rolled, annealed and cold rolled by a well-known method to obtain a steel plate with a thickness of 0.225 m.

Next, the well-known steps of decarburization annealing, application of an annealing separator, and final finish annealing were performed. A final annealed coil is cut out from a finished steel plate that has been subjected to insulation coating and heat flattening to a size of 10 cm in size x 50 cm in length, marked, and strained at 10 m intervals in a direction perpendicular to the rolling direction. This was used as a “before treatment” sample material. Then,
A slurry of 5bzOi powder of the drug at 50 cc of 10 g/HzO was applied so that the weight after drying was Q, 6 g/m, and the film was bound at an angle of 9°. After drying, the heat treatment conditions were varied at a temperature of 800 to 900°C for 1 hour to 5 to 120 minutes to vary the penetration depth of the penetrant. After this heat treatment,
This was used as a test material after treatment. After this, strain relief annealing was further performed at 800° C. for 2 hours to obtain a "after strain relief annealing" test material.

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 1.

As is clear from the examples shown in the margins below, grain-oriented electrical steel sheets with extremely low iron loss are produced, which have ultra-low iron loss and do not lose their iron loss improvement effect even when subjected to strain relief annealing after magnetic domain refining. Ru.

(Effects of the Invention) As explained above, according to the present invention, the iron loss of the steel sheet is significantly lowered by magnetic domain refining by the intruder, and thereafter, strain relief annealing is performed by heating to a high temperature. However, the iron loss improvement effect does not disappear, and an ultra-low iron loss electrical steel sheet that has never been seen before can be obtained.

[Brief explanation of drawings]

Figure 1 shows the depth of the intruder from the steel plate surface and the iron loss (W+vz
s. 2) is a graph showing the relationship between the improvement rate and FIG. 2 is a metal microscopic microstructure photograph (X 1000) showing the intrusions formed in the steel plate according to the present invention. Condolences 1 Figure Depth of intruder from steel plate surface (μm) Procedure correction - 1l
FC voluntary) November 1980: Manabu Shiga, Director General of LZ Japan Patent Office Patent n 2 filed on November 6, 1989, title of invention Ultra-low iron loss oriented TIL magnetic steel sheet 3, case of person making amendment r Relationship with Patent applicant name (665) Shin Nippon Riftetsu Co., Ltd. 4, agent address 5 IO, Toranomon-chome, Minato-ku, Tokyo 105
, Subject of amendment (1) “Claims” column of the description (2)
Drawings (Figure 1) 6. Contents of amendment (1) "Claims" amended as shown in the attached sheet a. (2) Amended as shown in the attached sheet for the first figure. 7. Attached list of category 8 (1) Amended claims 1 copy (
2) Drawing (Figure 1) 1 copy 26
Claims: In a grain-oriented electrical steel sheet that has been finish annealed, granular or lump-like intruders having a composition or structure different from that of the base steel or steel structure are present in the base steel at intervals?
Has the magnetic domain been subdivided by penetrating to a depth of 2μrrL or more? A grain-oriented electrical steel sheet featuring ultra-low iron loss.

Claims (1)

[Claims] In a finish-annealed grain-oriented electrical steel sheet, the steel sheet base metal has a steel component or structure different from the steel composition or steel structure in the base metal. An ultra-low core loss grain-oriented electrical steel sheet, characterized in that granular or lump-like intruders penetrate at intervals of 2 μm or more to a depth to refine magnetic domains.