JPS63278209A - Silicon steel plate having thermostable, extremely low core loss, and unidirectional properties - Google Patents

Abstract

PURPOSE:To obtain a silicon steel plate having excellent thermostable and unidirectional properties without bring about the deterioration in the performance because of a high temperature treatment by forming a mixture phase among Fe atoms, accelarating ions, and evaporation inos between tension films on the polishing treatment surface of the silicon steel phate as a substrate. CONSTITUTION:A mixture phase with base steels is mainly formed with at least on kind of nitrides and/or carbides chosen out of the above nitrides and/or carbides of Ti, Zr, Hf, V, Nb, Ta, Mn, Cr, Mo, W, Co, Ni, Al, B, and Si at the surface of a unidirectional silicon steel plate where its finishing annealing is performed and non-metallic substances are removed or further at its flat surface finished by polishing and through the mixture phase with these base steels, tension films having a layer of 0.005-5 mum, at least are firmly deposited on the surface of the above steel plate and further, another tension film is deposited by putting it together with an insulation coating baking layer on the initial tension film. The film thickness of the tension films is adaptable within a range 0.005-5 mum. When it is less than 0.005 mum, it does not contribute toword necessary tension and on the other hand, when it exceeds 5 mum, space factor and adhesion decrease.

Description

[Detailed Description of the Invention] (Field of Industrial Application) In recent years, efforts have been made to improve the electrical and magnetic properties of unidirectional silicon steel sheets, and in particular to meet the extreme demands of reducing iron loss. The remarkable development efforts are gradually bearing fruit, but one serious problem associated with their implementation is that when unidirectional silicon steel sheets are processed and assembled and then subjected to so-called strain relief annealing, their characteristics deteriorate. It has been pointed out that the disadvantage is that it inevitably causes deterioration and limits its usage.

In this specification, the following is related to the results of research and development that will lead to a new method that can advantageously meet the above requirements, regardless of whether or not it undergoes a high-temperature thermal history such as strain relief annealing. state

As is well known, unidirectional silicon steel sheets are products in which secondary recrystallized grains are highly concentrated in the (110) (OOIL or Goss orientation), and are mainly used in iron cores of transformers and other electrical equipment. The product's magnetic flux density (Bo.

It is required that the iron loss (represented by the Ltzs value) be high and the iron loss (represented by the Ltzs value) be low.

This unidirectional silicon steel sheet is manufactured through a wide variety of complicated processes, but numerous inventions and improvements have been made so far, and today a product with a thickness of 0.30 mm has magnetic properties of B.
oo 1.90T or more, l'1171501.05W/
The magnetic properties of products weighing less than 8 kg and with a plate thickness of 0.23 mm are 8.
, 01, unidirectional silicon steel sheets with ultra-low core loss of 89T or more and Lt/so 0.90W/kg or less are being manufactured.

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 is becoming widespread.

(Prior Art) Under these circumstances, recently, the surface of a unidirectional silicon steel sheet after finish annealing is irradiated with a laser in a direction approximately perpendicular to the rolling direction to introduce local microstrain to subdivide the magnetic domains. It has been proposed to reduce iron loss (see Japanese Patent Publications No. 57-2252, Japanese Patent Publication No. 57-53419, Japanese Patent Publication No. 5B-26405, and Japanese Patent Publication No. 58-26406).

This magnetic domain refining technology is effective for transformer materials for stacked iron cores that are not subjected to strain relief annealing. There is a drawback that the laser irradiation effect disappears because microstrains are released by annealing and the magnetic domain width becomes wider.

On the other hand, earlier in Japanese Patent Publication No. 52-24499, the surface of a unidirectional silicon steel sheet after finish annealing was mirror-finished, or the mirror-finished surface was coated with thin metal plating or an insulating coating was applied thereon. A method for manufacturing ultra-low core loss unidirectional silicon steel sheets has been proposed by coating and baking.

However, this method of improving iron loss through mirror finishing cannot be adopted from a process perspective, as it does not contribute enough to reducing iron loss despite the significant increase in cost. Furthermore, it has not been adopted in current manufacturing processes because it has problems with adhesion to steel plates after being subjected to strain relief annealing at a high temperature of 600° C. or higher for a long time. Japanese Patent Publication No. 56-4150 also proposes a method in which a steel plate surface is mirror-finished and then an oxide-based ceramic thin film is vapor-deposited. However, this method cannot be used in actual manufacturing processes because the steel sheet and the ceramic layer will separate when subjected to high-temperature annealing at 600° C. or higher.

(Problems to be Solved by the Invention) The inventors have overcome the disadvantage of increased costs, especially from the perspective of today's development of energy-saving materials, by taking advantage of the effect of improving iron loss due to the mirror finish described above. We believe that it is essential to overcome the problems of adhesion and durability of the tensile coating layer, which does not deteriorate in properties even during high-temperature treatment.Based on this basic understanding, we have developed fundamental changes in the conditions for forming the tensile coating, especially in PVD processing. It is an object of the present invention to achieve an advantageous ultra-low iron loss by making improvements.

(Means for solving the problem) As a result of the above study, Ti, Zr, and Hf are applied to the surface of the finish-annealed unidirectional silicon steel sheet from which non-metallic substances have been removed or the smooth finished surface by further polishing. .

V, Nb, Ta, Mn, Cr, Mo, W,
Co, Ni, Al, B and Si nitrides and/or
or at least one layer of a tensile coating of 0.005 to 5 μm, which is mainly composed of at least one kind selected from carbides, and is firmly adhered to the surface of the steel plate through a mixed phase of these carbides with the base iron, or Furthermore, we have invented a thermally stable, ultra-low core loss unidirectional silicon steel sheet that is characterized by having an insulating coated baking layer overlaid on this tension coating.

The explanation will proceed according to a specific experimental example that led to the success of this invention.

C: 0.046% by weight (hereinafter simply expressed as %), Si:
3.34%, Mn: 0.068%, Se: 0.
023%, Sb: 0.025%, Mo: 0.0
A silicon steel slab containing 25% was heated at 1360° C. for 4 hours and then hot-rolled into a hot-rolled plate with a thickness of 2.0 m+n.

After that, after homogenization annealing at 950℃ for 3 minutes,
It is cold rolled twice with an intermediate combustion of 0.2 minutes in between.
The final cold rolled sheet was 3+nm thick.

After that, decarburization and crystal annealing were performed in a wet Shiun atmosphere at 900°C, and then an annealing separator containing MgO as a main component was applied to the surface of the steel sheet, followed by secondary recrystallization annealing at 850°C for 50 hours. , purification annealing was performed at 1200° C. in saturated hydrogen for 5 hours.

Thereafter, the steel plate was first pickled in 82SOJ solution at 80°C to remove the forsterite base film on the surface of the steel plate.

Next, chemical polishing was performed in a solution of 3% HF and H2O2 to finish the surface of the steel plate into a mirror surface with a center line average roughness of 0.1 μm.

Thereafter, using the ion plating apparatus shown in FIG. 1, ion blating of TiN was performed on the polished surface to a film thickness of 0.5 μm.

In FIG. 1, 1 is a mirror-polished test substrate, 2 is a shutter, 3 is a crucible, 4 is an electron gun, 5 is a beam, 6 is an ionization electrode, 7 is a thermionic emission electrode, 8 is an N2.
This is an inlet for introducing a reactive gas such as C2H2 or 02.

After the above ion blasting, a coating treatment (formation of an insulating coated baked layer) with a coating liquid containing phosphate and colloidal silica as main components was performed.
Strain relief annealing was performed at ℃ for 5 hours.

For comparison with this, according to the conventional known technology b) 1μ
After performing copper plating treatment of m on the same polished surface, coating baking treatment was also performed with a coating liquid mainly composed of phosphate and colloidal silica, and then strain relief annealing was performed at 800 ° C. for 5 hours. Ta.

Table 1 summarizes the experimental results of the magnetic properties and adhesion of the product.

As is clear from Table 1, currently manufactured by process,
After applying a coating treatment on the forsterite base film formed on the steel plate surface during final annealing, 8
Normally processed product (a) after strain relief annealing at 00℃ for 5 hours
The magnetic properties of B and O are 1.905T.

W17zso is about 0.87 W/kg and the adhesion of the insulating film is good, but after final annealing, the forsterite film is removed by pickling, and then the surface is chemically polished to a mirror finish. The magnetic properties of products whose polished surfaces are coated with copper plating are as follows:
is 1.913T and IL715o is slightly improved to about 0.74W/kg, but adhesion is poor.

However, according to the present invention, the forsterite coating was removed after final annealing, the surface was chemically polished to a mirror finish, and the magnetic properties of the product (C), which was subjected to a similar coating treatment through ion footing treatment, were as follows. 1.9
20T, 'IIysa was 0.88 W/kg, which was not only an improvement in properties, but also extremely good adhesion of not only the tension coating but also the permanent coating and baking layer.

(Function) The improvement in magnetic properties and adhesion according to the present invention is achieved by forming Fe atoms, accelerated ions 1, and evaporated atoms a on the polished surface of a silicon steel plate serving as the substrate 1, as shown in the schematic diagram of FIG. By forming a mixed phase 8 with the tension film 9, the adhesion is greatly strengthened, and as a result, a strong tension film acts on the surface of the silicon steel plate, resulting in an ultra-low Iron loss is realized. Since the function of plastic microstrain is not used here, there is no problem with thermal stability, and the electrical and magnetic properties are not affected by high-temperature thermal history such as strain relief annealing.

Here, the center line average roughness of the finished surface is Ra≦0.4μm
It is best to have a mirror state of Ra>Q, 4
When the thickness is μm, the surface is rough, so there is little hope for a significant reduction in iron loss.

Next, the thickness of the tension coating is suitable in the range of 0.005 to 5 um; if it is less than 0.005 um, it will not be able to contribute to providing the necessary tension, while if it exceeds 5 um, the space factor and adhesion will be affected. disadvantages arise.

Strong adhesion on the mirror-finished surface via the mixed phase of this tensile coating is achieved by PVD (Physical
al Vapor Deposition) or C
VD (Che-mical Vapor Deposit
tion).

Next, the manufacturing process of a unidirectional silicon steel sheet according to the present invention will be explained.

The starting material is a conventionally known unidirectional silicon steel material composition, such as ■C: 0. Old ~ 0.050%, Si: 2.50 ~ 4.5
%, Mn: 0.01-0.2%, Mo: 0.
003-0.1%, Sb: 0.005-0.2%,
Total of one or two types of S or Se, 0.005~
Composition containing 0.05% ■C: 0.01-0.08%
, Si: 2.0-4.0%, Sol Al: 0.
005-0.06%, °S: 0.005-0.05%,
N: 0.001-0. Old %, Sn: 0.01-0.
5%, Cu: 0.01-0.3%, Mn: Q, composition containing old ~ 0.2% ■C: 0. Old ~0.06%,
Si: 2.0-4.0%, 3: 0.005-0.05
%, B: 0.0003-0.020%, N:O
,OOl ~0.01%, Mn: 0.01~0.2
Next, the hot-rolled sheet is subjected to homogenization annealing at 800 to 1100°C and then
One-time cold rolling method, in which the final plate thickness is obtained by two cold rolling steps, or two-step cold rolling method, in which intermediate annealing is usually performed at 850°C to 1050°C, and then further cold rolling is performed.In the latter case, the first rolling rate is 50
% to about 80%, the final rolling reduction is about 50% to 85%, and the final cold rolled plate thickness is 0.15 mm to 0.35 mm.

After finishing the final cold rolling, the steel plate finished to the product thickness is surface degreased and then subjected to decarburization and primary recrystallization annealing in wet hydrogen at 750°C to 850°C.

After performing such treatment, an annealing separator is applied to the surface of the steel sheet. At this time, it is generally effective to prevent the formation of forsterite, which is essential for forming after final annealing, in order to simplify the subsequent mirror finishing of the steel sheet, so an MgO-based separator is used as the annealing separator. In addition to cases, especially Al2O3, ZrO2, TlO2, etc.
It is preferable to mix 0% or more of MgO into MgO.

After that, secondary recrystallization annealing is performed, but this step is (110)
This is done to sufficiently develop secondary recrystallized grains with <001> orientation, and is usually box annealed to immediately
This is done by raising the temperature above ℃ and maintaining it at that temperature.

In this case, in order to develop a highly uniform secondary recrystallized grain structure in the (110) <001> orientation, the
It is more advantageous to carry out retention annealing at a low temperature of 00°C, and in addition, for example, 0.5-b annealing may be used.

Purification annealing after secondary recrystallization annealing is performed at 1100°C in saturated hydrogen.
It is necessary to perform annealing for 1 to 20 hours to achieve purification of the steel plate.

After this purification annealing, nonmetallic substances such as forsterite coatings or oxide coatings on the surface of the steel sheet are removed by known chemical removal methods such as pickling, mechanical removal methods such as cutting and grinding, or a combination thereof.

After this oxide removal treatment, if necessary, the steel plate surface is polished to a mirror-like state (centerline average roughness 0.4 μm or less).

After removing non-metallic substances or mirror polishing, Ti, Zr, Hf, V, Nb, Ta, M are processed by CvD, ion blasting or ion implantation.
n, Cr.

At least one ultra-thin tensile coating is formed which mainly consists of at least one selected from Mo, W, Co, Ni, Al, B, and Si nitrides and/or carbides.

Moreover, it is effective to form this ultra-thin tension coating with a thickness of about 0.005 to 5 μm. A coating with a thickness of 0.005 μm or less has a small tension effect, so it has little effect on reducing iron loss, and a film with a thickness of 5 μm or more thickens the space factor and is not economical, so the thickness of the tension coating is 0.
0.005 to 5 μm is suitable.

Furthermore, an insulating film containing colloidal silica or phosphate and colloidal silica as main components is applied and baked on the ultra-thin tensile film produced in this way, and then subjected to long-term strain relief annealing at a high temperature of 600°C or higher. Naturally, it is necessary for transformers to have good adhesion and no deterioration of magnetic properties even when exposed to heat, and the formation of this insulating baked layer and the subsequent strain relief annealing method can be done using conventionally known methods. May be used.

In addition, improvements in magnetostrictive compression properties can also be achieved with the present invention.

(Example) Example I C: 0.047%, Si: 3.4%, Mn: 0.0
62%, Mo + 0.025%, Se: 0.02
2%, Sb: 0.020%.
After uniform annealing at 00° C. for 3 minutes, cold rolling was performed twice with intermediate annealing at 950° C. to obtain a final cold rolled sheet with a thickness of 0.23 mm.

After decarburization annealing in wet hydrogen at 820°C, Mg is deposited on the surface of the steel sheet.
After applying an annealing separator containing D as the main component, it was heated at 850℃ for 5
Secondary recrystallization annealing was performed for 0 hours, and purification annealing was performed in saturated hydrogen at 1200° C. for 8 hours.

After that, after removing the forsterite film by pickling, 3
%HF and H2O2 solution to give a mirror finish.

After that, using the apparatus shown in Figure 1, ion blating was performed for 3 minutes at an ionization voltage of 10 KV to form a TiN film with a thickness of 0.5 μm.
A tension film was formed.

Next, an insulating coated and baked layer containing phosphate and colloidal silica as main components was formed, and then strain relief annealing was performed at 800° C. for 2 hours.

The magnetic properties and adhesion of the product at that time were as follows.

Magnetic properties: B1o=1,917, 11117/So
-0.69W/kg Adhesion: 1 at bending radius 30mm
Even after bending by 80 degrees, the film could not be peeled off and the adhesion was good.

Example 2 C: 0.062%, Si: 3.3%, Mn: 0.0
90%, Al: 0.025%, S: 0.030%,
A hot rolled sheet containing N: 0.0068% was heated to 1150
After equalization annealing for 3 minutes at ℃, rapid cooling treatment was performed, and then 30
Warm rolling was performed at 0° C. to obtain a final cold-rolled sheet with a thickness of 0.20+++ m.

After decarburization annealing in wet hydrogen at 850°C, the surface is coated with MgO.
After applying an annealing separator mainly composed of
After secondary recrystallization by raising the temperature to 150°C at a rate of 8°C/hr, purification annealing was performed at 1200°C for 8 hours in saturated hydrogen.

Thereafter, the forsterite film was removed by pickling, and then chemically polished in 3% HP and H2O2 solution to give a mirror finish.

After that, nitrogen ions were implanted for 3 minutes at an ion acceleration voltage of 49 KV using the ion implantation method to form a film with a thickness of 0.2
After forming an ultra-thin tension film of Si3N at μm, and then forming an insulating coating and baking layer containing phosphate and colloidal silica as main components, strain relief annealing was performed at 800°C for 2 hours. Ta.

The magnetic properties and adhesion of the product at that time were as follows.

Magnetic properties: B+o=1.93T, W+, zso
=0.68W/kg Adhesion: 18 at bending radius 30mm
Even when bent by 0°, it could not be peeled off, and the adhesion was good.

Example 3' C: 0.044%, Si: 3.45%, Mn:
0.066%, Se:Q, 023%, Sb:
A unidirectional silicon steel sheet containing Mo: 0.025% and Mo: 0.026% was heated at 1360° C. for 4 hours, and then hot rolled into a hot rolled sheet having a thickness of 2.20 mm. Thereafter, after equalization annealing at 900°C for 3 minutes, cold rolling was performed twice with an intermediate annealing at 950°C for 3 minutes, resulting in a 0.2
The final cold-rolled sheet had a thickness of 3+++m.

After that, after performing primary recrystallization annealing which also serves as decarburization in wet hydrogen at 820°C, Al2O3 (60%), Mg0 (30%)
%).

After applying an annealing separator mainly composed of ZrO□ (5%) and T102 (5%), secondary recrystallization annealing was performed at 850°C for 50 hours, followed by purification in dry H2 gas at 1200°C for 8 hours. Annealing was performed.

After removing oxides on the steel plate surface by light pickling,
The surface of the steel plate was polished to a mirror finish by electrolytic polishing.

Then (a) magnetron sputtering method, (b) B
B (Blectron Beam) + RF (Ra
dio Frequency) method, (C) HCD (Ho
After forming a tension film of TiN using an ion blating device using the MultiArc method,
Strain relief annealing was performed at ℃ for 3 hours to obtain a product. Table 2 shows the magnetic property values of the product and the X-ray diffraction results of the TiN coating.

Table 2 As is clear from Table 2, the magnetic properties [t
o Mo 1.91~1.92T, Lt7so is 0.6
All of them are extremely good, such as 9 to 0.72W/kg. In addition, the X-ray diffraction results of the thin film on the surface show (a), t
and (6), only TiN peaks, (b)
Under the conditions of , TiN peaks are dominant, but Ti p
peaks slightly, and under condition (C) TiNpeaks
is the main component, but a small amount of T12N and TiN peaks were detected, but peaks of this magnitude other than TiN do not have a large effect on the magnetic properties. The adhesion of all products at this time was 18o with a bending radius of 25+nm or less.

It was good with no peeling even after bending.

Example 4 C: 0.042%, Si: 3.32%, Mn: 0.
062%, Mo: 0.022%, Se: 0.0
A hot rolled sheet containing 21% and Sb: 0.025% was homogenized at 900 t' for 3 minutes, then cold rolled twice with an intermediate annealing at 950°C for 3 minutes. 0
．． A final cold-rolled sheet with a thickness of 23 mm was obtained.

After that, after performing primary recrystallization annealing that also serves as decarburization in wet hydrogen at 820°C, the steel plate surface is coated with Al2O3 (70%>
After applying an annealing separator consisting of MgO (25%) and 2rO2 (5%), secondary recrystallization annealing was performed at 850°C for 50 hours, followed by purification annealing at 1200°C for 7 hours in saturated hydrogen. did.

Thereafter, in (a) the oxide film on the surface of the steel plate was removed by pickling, and in (g) the oxide film was removed by pickling, followed by electrolytic polishing to give a mirror finish with a center line average roughness of 0.04 μm or less. After that, 1.2μ was obtained by ion brating.
A TiN film with a thickness of m was formed.

Thereafter, one part was coated with a coating film mainly composed of phosphate and colloidal silica, and then subjected to strain relief annealing at 800° C. for 5 hours to produce a product. The magnetic properties of the product at that time are shown in Table 3 in comparison with the current product having a forsterite coating.

The current product undergoes primary recrystallization annealing that also serves as decarburization in wet hydrogen at 820°C, and then coats the surface of the steel plate with an annealing separator containing MgO as the main component. Next, recrystallization annealing was performed, followed by purification annealing at 1200° C. for 7 hours in saturated hydrogen. Thereafter, the whole stellite film was baked and then subjected to strain relief annealing at 800° C. for 5 hours to produce a product.

In addition, the adhesion of the product at this time is based on the bending radius of 25.
mm or less, and there was no peeling even when bent by 180°, which was good.

Table 3 Example 5 C: 0.043%, Si: 3.32%, Mn: 0.
066%.

A hot rolled silicon steel plate (2,0 mm thick) containing Se: 0.019%, Sb: 0.025% and Mo: 0.023% was annealed twice at 950°C with intermediate annealing for 3 minutes in between. A cold rolled plate having a thickness of 0.23+n+n was obtained by cold rolling. After that, after primary recrystallization annealing was performed at 820℃ for 3 minutes, which also served as decarburization, Al2O3 (60%>
Mg0 (35%), Zr02 (3%), T102
(2%) was applied as a slurry.

After that, after performing secondary recrystallization annealing at 850°C for 50 hours, and after that, purifying annealing with dry hydrogen at 1200°C for 6 hours, surface oxides were removed by pickling, and the steel plate surface was electrolytically polished. was made into a mirror state. Then CVD
(no mark in Table 4), ion brating (○ mark in Table 4), and ion implantation (Δ mark in Table 4)
After forming various thin films (approximately 0.7 to 1.5μ thick) by baking the coating film, which mainly consists of phosphate and colloidal silica, strain relief annealing was performed at 800°C for 5 hours. Ta. Table 4 summarizes the magnetic properties of the products at that time.

In addition, the adhesion of the product at this time is based on the bending radius of 25.
It was good with no peeling after bending 180° with a diameter of 180° or less.

Table 4 Example 6 C: 0.043%, Si: 3.37%, Mn: 0.
063%, Mo: 0.025%, Se: 0.0
A hot rolled sheet containing Sb: 22% and Sb: 0.025% was prepared.

This hot-rolled sheet was homogenized at 900°C for 3 minutes and then heated to 950°C.
Cold rolling was performed twice with intermediate annealing at 0.2 °C.
A final cold-rolled sheet with a thickness of 3 mm was obtained.

After that, after decarburization annealing in wet hydrogen at 820℃, A
l2O3 (75%), Mg0 (20%), Zr02
After applying an annealing separator mainly composed of (5%) 850
A secondary recrystallization annealing at 1200° C. for 50 hours and a purification annealing in H 2 at 1200° C. for 8 hours were performed.

Thereafter, the oxide film on the surface of the steel plate was removed by pickling, and then chemically polished in 3% IIF and H2O2 solution to give a mirror finish. Thereafter, various compound thin films were formed by CVD (no mark in Table 5), ion blating (○ mark in Table 5) and ion implantation (Δ mark in Table 5).
It was formed to have a thickness of 0.9 μm.

Thereafter, the surface of the sample subjected to these treatments was subjected to a baking treatment to form an insulating coating mainly composed of phosphate and colloidal silica, and then strain relief annealing was performed at 800° C. for 2 hours.

The magnetic properties and magnetostrictive compressive stress properties of the product at that time,
(Magnetostriction values λpp when the compressive stress σ is 0.4 and 0.6 kg/mm2) are summarized in Table 5.

Example 7 C: 0.056%, Si: 3.29%, Mn: 0.
078%, Al: 0.025%, S: 0.030%
, Cu:Q, 1%.

Sn: 1 unidirectional silicon steel containing 0.05%
After heating at 440℃ for 5 hours, hot rolling
．． A hot rolled sheet having a thickness of 7+nn+ was obtained.

Thereafter, uniform annealing was performed at 1100° C. for 3 minutes, followed by rapid cooling. After that, it was warm rolled at 350°C to 0.2
The final cold rolled sheets had thicknesses of 0.0.23, 0.27 and 0.30+n+n.

After that, after performing primary recrystallization annealing which also serves as decarburization in wet hydrogen at 850°C, A1203 (70%), Mg0 (20
%).

T102 (5%), Zr02 (5%) f:l) Annealing [FIJ coating 1. After that, secondary recrystallization annealing was performed at 850°C for 50 hours, and purification annealing was performed at 1200°C for 5 hours in dry gas.

Thereafter, the oxide film on the surface of the steel plate was removed by pickling, and then electropolishing was performed to finish the surface of the steel plate to a mirror finish.

After that, a thin film of Cr2N was formed using PVD (ion blating device), and then an insulating film mainly composed of phosphate and colloidal silica was baked.
Strain relief annealing was performed at 00°C for 3 hours.

At that time, the product's magnetic properties by plate thickness, the film thickness of the Cr2N thin film, and the compressive stress properties of magnetostriction (compressive capacity σ is 0.4 kg/
The magnetostriction value λ1.mm2 and 0.6 kg/m+n2. ) are summarized in Table 6.

Table 6 32-Example 8 (a) C: 0.042%, Si: 3.36%, Mn
: 0.062%, Mo: 0.024%, Se
: 0.021%, Sb: 0.025% (b) C:
0.056%, Si: 3.36%, Mn: 0.06
8%, AI=(LO26%, S:0.029%, N
: 0.0069%.

Hot rolled sheets containing Cu: 0.1% and Sn: 0.05% were prepared.

First, the hot-rolled sheet (a) was uniformly annealed at 900° C. for 3 minutes and then cold-rolled twice with intermediate annealing at 950° C. to obtain a final cold-rolled sheet with a thickness of 0.20 mm.

On the other hand, the hot rolled sheet (b) was uniformly annealed at 1080° C. for 3 minutes and then rapidly cooled, and then warm rolled at 300° C. to obtain a final cold rolled sheet having a thickness of 0.20 mm.

After that, all cold rolled sheets were decarburized and annealed in wet hydrogen at 830°C, and 81□03 (75%) and Mg0 were added to the surface of the steel sheets.
(20%), after applying an annealing separator mainly composed of Zr02 (5%), the sample made of material (a) was heated to 850°C
After secondary recrystallization annealing for 50 hours at
After secondary recrystallization by raising the temperature from .degree. C. to 1050.degree. C. at a rate of 5.degree. C./hr, purification annealing was performed in saturated hydrogen at 1200.degree. C. for 8 hours.

After that, the oxide film was removed by pickling, and then 3% HP
Chemically polished in 820□ liquid to give a mirror finish.

Then use CVD equipment (i) TiC14, H2 and N
20) TiN thin film by mixed gas, (ii) TiC1
4, H2, N2, and CH4 mixed gas, Ti(CN)
and (iii) TiC1, H2, N2 and C
A thin film of TiC is coated with a mixed gas of H4 at a temperature of 0.7
It was formed to have a thickness of μm. Also using ion brating and ion implantation equipment (iv)
0.7-0.9μm of Ti(CN) and (v)TiC
A thick thin film was formed.

Thereafter, the surface of the sample subjected to these treatments was subjected to a baking treatment to form an insulating coating mainly composed of phosphate and colloidal silica, and then strain relief annealing was performed at 800° C. for 2 hours.

The magnetic properties and magnetostrictive compressive stress properties of the product at that time (
Compressive stress σ is 0.4. Magnetostriction λ2 under $ and 0.6 kg/mm2. ) are shown in Table 7.

-34= Example 9 C: O1O'43%, Si: 3.42%, Mn: 0
．． 069%, Se: 0.021%.

After heating unidirectional silicon steel containing Sb:Q, 025% and MO:0.025% at 1400°C for 3 hours,
It was hot rolled into a 1.8-2.7+nmO hot rolled sheet. After that, after uniform annealing at 900°C for 3 minutes, cold rolling was performed twice with an intermediate annealing at 950°C for 3 minutes to obtain a 0.20
．． The final cold rolled sheet was 0.23, 0.27 m+++ and 0.30 mm thick.

After that, after primary recrystallization annealing which also serves as decarburization in wet hydrogen at 830°C, MgO (20%), 81203 (70%)
).

After applying an annealing separator of T102 (5%) and Zr02 (5%), secondary recrystallization annealing was performed at 850°C for 50 hours.
Purification annealing was performed in dry H2 gas at 1200°C for 5 hours. Thereafter, oxides on the surface of the steel plate were removed by light pickling, and then electrolytic polishing was performed to finish the surface of the steel plate to a mirror finish.

After that, a thin film of TiN was formed using a PVD device (ion blating device), and an insulating coating mainly composed of phosphate and colloidal silica was baked.
Strain relief annealing was performed at 00°C for 3 hours. At that time, the thickness side magnetic properties of the product, the film thickness of the TiN thin film, and the compressive stress properties of magnetostriction (compressive stress σ is 0.4 kg/++++n2
and the value of magnetostriction λ2. at 0.6 kg/mm”)
are shown in Table 8.

Table 8 7mm2 = 37- (Effects of the Inventions) Each of the inventions prevents any performance deterioration resulting from high-temperature treatment when using unidirectional silicon steel sheets that undergo high-temperature thermal history, such as strain relief annealing. A unidirectional silicon steel sheet with excellent thermal stability is provided.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of ion plating, and FIG. 2 is an explanatory diagram showing deposition behavior of accelerated ions and vapor deposited atoms.

Claims (1)

[Claims] 1. Ti, Zr, Hf, V, Nb, T
It mainly consists of at least one kind selected from nitrides and/or carbides of a, Mn, Cr, Mo, W, Co, Ni, Al, B and Si, and forms a surface of the steel sheet through a mixed phase with the base iron. and at least one layer firmly adhered to 0.0
A thermally stable, ultra-low core loss unidirectional silicon steel sheet characterized by having a tensile coating of 0.05 to 5 μm. 2. After removing the non-metallic substances on the surface of the unidirectional silicon steel plate that has been finish annealed, the T
i, Zr, Hf, V, Nb, Ta, Mn, Cr, Mo,
The at least one material is mainly composed of at least one kind selected from nitrides and/or carbides of W, Co, Ni, Al, B, and Si, and is firmly adhered to the surface of the steel sheet through a mixed phase of these with the base iron. A thermally stable, ultra-low iron loss unidirectional silicon steel sheet, characterized by having one layer of a tensile coating of 0.005 to 5 μm. 3. Ti, Zr, Hf, V, Nb, T
It mainly consists of at least one kind selected from nitrides and/or carbides of a, Mn, Cr, Mo, W, Co, Ni, Al, B and Si, and forms a surface of the steel sheet through a mixed phase with the base iron. At least one layer of O.
1. A thermally stable, ultra-low iron loss unidirectional silicon steel sheet comprising a tensile coating of 0.005 to 5 μm, together with an insulating coated and baked layer overlaid on the tensile coating. 4. After removing the non-metallic substances on the surface of the unidirectional silicon steel sheet that has been finish annealed, polish the surface to make it smooth.
i, Zr, Hf, V, Nb, Ta, Mn, Cr, Mo,
The at least one material is mainly composed of at least one kind selected from nitrides and/or carbides of W, Co, Ni, Al, B, and Si, and is firmly adhered to the surface of the steel sheet through a mixed phase of these with the base iron. Thermal stability, ultra-low iron loss unidirectionality characterized by having one layer of 0.005 to 5 μm tension coating, and having an insulating coated and baked layer deposited on top of this tension coating. Silicon steel plate.