JPH0238527A - Manufacture of grain-oriented silicon steel sheet with low iron loss free from deterioration in characteristic due to stress relief annealing - Google Patents

Abstract

PURPOSE:To stably and inexpensively manufacture a grain-oriented silicon steel sheet with low iron loss free from deterioration in characteristics even if subjected to stress relieving annealing by subjecting a finish-annealed silicon steel sheet to magnetic smoothing treatment by means of electrolysis and then removing the surface of the steel sheet linearly in a direction across the rolling direction. CONSTITUTION:A grain-oriented silicon steel sheet after decarburizing annealing and finish annealing is subjected to anodic electrolysis in an aqueous solution containing one or more kinds among water-soluble halides, such as NaCl, by which magnetic smoothing treatment is applied to the surface of the steel sheet. Subsequently, a part of the matrix on the above steel-sheet surface is removed into the state of continuous or intermittent lines extending in a direction across the rolling direction, or, metal plating into the state of the same lines as mentioned above may be applied to the steel-sheet surface. It is preferable that the width of the above linearly removed part or metal-plated part is regulated to about 0.1-0.4mm and also the spacing between respective linearly removed parts or metal-plated parts mentioned above is regulated to about 2.0-10.0mm. Then, an insulating film of tension-giving type is formed on the steel-sheet surface by means, e.g., of phosphate-type coating containing colloidal silica. By this method, the grain-oriented silicon steel sheet free from deterioration in characteristics even if subjected to subsequent stress relieving annealing and excellent in iron loss can be obtained.

Description

[Detailed Description of the Invention] (Industrial Application Field) After the energy crisis a few years ago, the trend for electrical equipment with lower power loss has become even stronger, and as a key advantage of these, the need for lower iron loss has increased. There was a demand for low-quality electrical steel sheets.

The present invention advantageously satisfies the above requirements, and particularly relates to a method for producing a grain-oriented silicon steel sheet with low core loss whose core loss properties do not deteriorate even when subjected to strain relief annealing.

(Prior Art) Iron loss in silicon steel sheets consists of thin current product and hysteresis loss. An effective means of reducing the iron loss of silicon steel sheets is to reduce the sheet thickness, and this method contributes greatly to the reduction of iron loss and, in turn, to energy conservation, mainly by reducing the eddy current product. However, the plate thickness is 1]
When the value becomes less than Llil, the ratio of hysteresis loss to total iron loss increases considerably. Factors that affect hysteresis loss include the orientation of crystal grains, the degree of impurities, the influence of surface coatings, and the roughness of the steel sheet surface.

For example, Japanese Patent Publication No. 52-24499 ``4'' describes methods for reducing hysteresis loss, particularly by improving the surface properties of steel sheets.
A method has been proposed in which surface oxides are removed from a grain-oriented silicon steel sheet after finish annealing by pickling, and the surface is then chemically polished or electrolytically polished to a mirror-like state. Also, special public service 1986-4
Japanese Patent No. 150 discloses a technique for removing non-metallic substances from the surface of a grain-oriented silicon steel sheet, and then applying a ceramic thin film to the surface by chemically polishing or electrolytically polishing the surface.

Furthermore, in Japanese Patent Application Laid-open No. 60-89589, Almiry “
A technique has been disclosed in which surface oxides of a grain-oriented silicon steel sheet are removed after secondary recrystallization using an annealing separator containing as a main component, followed by chemical polishing or electrolytic polishing. Furthermore, JP-A No. 60-39123 discloses a technique in which the amount of oxides on the surface is controlled using an annealing separator containing alumina as a main component, and then chemical polishing or electrolytic polishing is directly applied without pickling. is disclosed.

(Problems to be Solved by the Invention) However, none of these techniques has been industrially implemented today, although the effect of reducing iron loss is very clear.

The reason for this is that in the case of chemical polishing, IP + II zO□ and II 3 P Op + II used as polishing liquid
This is because □0□ etc. are expensive, resulting in high costs. Similarly, in the case of electrolytic polishing, the phosphoric acid baths, sulfuric acid baths, phosphoric acid-sulfuric acid baths, and perchloric acid baths that are commonly used as polishing solutions all contain highly concentrated acids as their main component, The cost is high due to the use of chromate, butic acid, organic compounds, etc. as additives, and there are many unresolved problems in processing steel sheets in large quantities, such as homogeneity, productivity, and early deterioration of the liquid. It is from.

Yet another major drawback that prevents industrialization is that it is difficult for insulating coats to adhere to mirror-polished surfaces.

In other words, the conventionally known phosphate-based coatings 1 to 1 and ceramic coating 1 had poor adhesion due to their mirror surfaces and could not withstand actual use.

Furthermore, JP-A-61-1.83457 discloses that after finish annealing, the surface coating of a grain-oriented silicon steel sheet is removed, and then, by plating, penetrants are formed at intervals, or the surface coating is removed at intervals. A method has been disclosed in which the magnetic domain is removed by removing the magnetic material, and then a penetrant is formed by plating to refine the magnetic domain.

This method has a problem in that the effect of reducing iron loss is small compared to the method of reducing hysteresis loss by making the surface of the steel plate mirror-like.

The present invention advantageously solves the problems described in 2. Even if mirror polishing is performed by electrolytic rIII polishing or chemical polishing, the magnetic wall remains magnetically smooth, which means that the movement of the domain wall, which causes hysteresis loss, is avoided. The purpose is to form a surface that does not cause interference and further subdivide the magnetic domains to reduce eddy current loss and realize low iron loss in grain-oriented silicon steel sheets.

(Means for solving the problem) In this invention number J, a finish annealed grain-oriented steel sheet is subjected to magnetic smoothing treatment by electrolysis in an aqueous solution containing one or more water-soluble halides. After that, (1) a method of removing a part of the base iron on the surface of the steel plate in a continuous or discontinuous line extending across the rolling direction, and then coating the steel plate surface with a tension-applying insulating coating; 2) A method in which a continuous or discontinuous linear metal plating extending across the rolling direction is applied to the surface of a steel sheet, and then a tension-applying insulating coating is formed on the surface of the steel sheet.

(Function) The results of a re-examination of the effects of various surfaces on iron loss, which formed the basis of this invention, will be described below.

The first point is that it is mainly the surface oxide that has a large effect on the hysteresis loss, and the surface irregularities do not necessarily have to be mirror-like. The mirror state is an optical concept, and is not defined quantitatively, but usually refers to a surface average length Ra of 0.4 μm or less, preferably 171 m or less.

Figure 2 shows a conventional grain-oriented silicon steel sheet with oxides present on the surface, a grain-oriented silicon steel sheet that has been subjected to mirror polishing treatment, and a grain-oriented silicon steel sheet that has been further pickled to roughen the surface. As is clear from the figure, even if the specular surface is lost due to pickling G, the iron loss has not deteriorated much.

In order to obtain a low hysteresis 1j) silicon steel sheet, it is not necessarily necessary to make it a mirror surface, but it is sufficient to have a so-called magnetically smooth surface, so electrolytic polishing and Kagakuken 19 +1 are not necessarily required. Rather than being an essential condition, chemical treatments, etc. can be selected more freely.

However, it goes without saying that during the process of magnetic smoothing of a silicon steel sheet, the introduction of strain on the surface of the steel sheet should be avoided as much as possible since it will deteriorate the fall+n.

Next, we will explain the mirror polishing phenomenon that characterizes the electrolytic polishing method. In electrolytic polishing, the polished surface is used as an anode.
When no current is passed in a strong acid or strong alkaline electrolyte, the metal elutes from the surface as ions due to an electrolytic reaction, but a υJ viscous film is formed between the metal surface and the electrolyte. Since this viscous film is thinner in the convex parts of the surface, more current flows through the convex parts, and more current is leached out in the convex parts than in the concave parts, and the metal surface is said to be finished to a mirror-like finish with no irregularities. Therefore, chemical polishing and electrolytic polishing can be said to be methods for smoothing metal surfaces, completely independent of crystal grain size and orientation. In other words, the surface obtained by chemical polishing or electrolytic polishing is characterized by having high gloss by smoothing it regardless of the underlying crystals.

The second finding is that when 4J silicon steel is electrolytically treated with an aqueous chloride solution, the surface properties of the steel sheet vary greatly depending on the grain orientation of the surface of the steel sheet.

Conventionally, electrolytic treatment using chloride has not been carried out because it is not effective in obtaining a mirror surface (iJt 1g surface), but the inventors have widely recognized the possibility of electrolytic treatment based on the first finding mentioned above. As he was searching for it, he conducted TI'Il' recognition experiments on chlorides and discovered the above-mentioned peculiar phenomenon.

Fig. 2 shows a microscope & [i woven sword strand] showing that the morbosity of the crystal plane after electrolytic treatment differs depending on the difference in plane orientation.

FIG. 2A shows the case where the (no) plane of the crystal grain is inclined by 5° with respect to the rolling plane Q, and has a unique #Irl fFl-like surface morphology. These 8L14 mesh grains are called graining-like surfaces because they are formed by dispersing and adjoining depressions in the grains, which resemble crystal grains, and are much worse than the graining surfaces obtained by electrolytic etching.

FIG. 2B shows the same case of <11° inclination, exhibiting a scaly morboron. Furthermore, the cow IC is 2
This is a case where it is tilted by 5° and has a wood texture.

Go to Figure 2 if you have a unique morbology.
As can be seen in the figure, it has a net 1]-like & JI K, fllA pattern with a mirror surface, and the Mac 1:I appearance has the appearance of a pickled surface with grain boundaries.

Furthermore, t[j What is important is that such a peculiar 31? The surface having an I mesh structure is obtained when a silicon steel plate having one +11.0) surface is electrolytically treated using an aqueous chloride solution as an electrolyte, and the above network structure Gnl magnetic The surface must be perfectly smooth.

In Fig. 1 (21) or (b), a prime key formed mainly by (+, +0) face 114 is connected to NaC1 and charged to i1.
'+: Shows the results obtained after improving the iron loss of element (A) obtained when treated. Also, for comparison, the same figure shows the results obtained after treatment with mixed acid (CrO: + 10%-1hl) (L). Electrolytic Research U I
The results of a study on iron loss improvement in grain-oriented silicon steel sheets with a more mirror-like surface were also found.

As is clear from the figure, the improvement in iron loss is greater when a chloride bath is used.

Note that the experiment described in 1-1 was conducted using 71 scale 2 as an N8C1 electrolyte.
0%, current density: 100A/dm"
Electrolytic treatment was performed under conditions of seconds.

Furthermore, ultra-high wave vibration is applied to the 6mm electrodeposited tire coating on the surface of the steel plate after electrolytic treatment or mirror polishing treatment. grooves were formed at 5 mm intervals, and then a TiN film was formed by ion blating treatment (see figure (a)), and the steel plate surface was similarly electrolyzed or mirror-finished. A screen with 0.15 mm wide slits formed at 511 m intervals is placed in close contact with the slits so that the slits are perpendicular to the rolling direction, and the steel plate is immersed in an electrolytic solution containing Sb to apply sb plating in a cotton-like manner. A subsequent investigation was carried out on the one coated with a TiN film through the rating process (see FIG. 6(b)). For comparison, a steel plate in which a TiN film was directly formed on the surface of the steel plate after electrolysis or mirror polishing treatment was also subjected to GLFL examination. Further, after the TiN film was formed, the iron loss was also investigated after strain relief annealing was performed at 800° C. for 13 hours in a N4 atmosphere.

As is clear from Figures (a) and (b), the iron loss is greatly improved when a part of the base iron is removed in a groove shape and when Sb plating is applied in a cotton shape. ,
Even if strain relief annealing is performed thereafter, iron loss does not deteriorate.

The physical reason why the iron loss of the steel sheet according to this invention is better than that of products with a mirror surface produced by conventional methods such as electrolytic polishing or chemical polishing has not been completely elucidated, but the first reason is magnetic In order to be visually smooth, geometric smoothness is not required to be very high.Secondly, in this invention, since grain boundaries or step-like or groove-like recesses are formed, the width of the magnetic domain can be narrowed. Thirdly, it is thought that electrolytic polishing would cause deterioration due to an oxide film that forms on the mirror surface, or that this would not occur with the steel sheet of this invention. be done.

In addition, the iron loss is improved by removing part of the base iron.
This is thought to be because the locally existing base metal removed portion subdivides the magnetic domain, and furthermore, TiN enters the removed portion as a foreign substance, thereby locally forming a magnetically heterogeneous portion. Similarly, the reason why iron loss is improved by applying linear metal plating is that the presence of local foreign substances (plating) on the surface of the steel sheet results in the local formation of magnetic foreign parts. Conceivable.

By forming a tensile ('t'j-shaped) on the steel plate that has undergone these treatments, further reduction of iron loss can be achieved.
Even if strain relief annealing is performed thereafter, iron loss does not deteriorate.

This invention will be specifically explained below.

In this invention, an LJ raw steel slab is hot rolled according to a conventional method, then cold rolled with intermediate annealing to obtain the final plate thickness, decarburized annealed, and then final finish annealed. .

Conventionally, Mg was used as an annealing separator during final annealing to form a forsterite film at the same time.
Annealing separators mainly composed of O have been mainly used,
For example, AI! is formulated to prevent the formation of such Forstera I1 film. , z03, etc. as a main component, and an inert MgO, Ca, or Sr compound may be used as a separating agent.

Next, the surface oxidation layer of the final annealed plate is removed.

Removal methods include chemical methods such as pickling and mechanical methods such as emery polishing. Although there are no particular limitations, if the surface oxide layer is removed by mechanical methods, distortion may easily occur inside the board. Since such strain cannot be relieved by subsequent electrolytic treatment, it is preferable to remove surface oxides by pickling treatment.

Then, the surface from which the surface oxide layer has been removed is magnetically smoothed by anodic electrolytic treatment.

The electrolytic bath uses an aqueous solution containing one or more water-soluble halides.

Here, water-soluble halides include Ill, Ni14
Chlorides of Cn and various metals or acids with F, Br, I as anions, water-soluble ones among their alkali, alkaline earth, other metal salts and ammonium salts, and fluorides such as borofluorides. (upa salt) and silicofluoride (SiF2 salt), which are water-soluble. Examples of water-soluble halides include HCl2. NaCl
! , 1KCj2. NHsCj2. MgCj2z,
CaCj2zAj2CI2: +1 liver, NaF, KF
, N114FIllBr, NaBr, KBr.

MgBr2. CaBr2. NlI4Br, III
, Nal, KI, Nll, I, CaI2゜Mg
h, t12.5iF6. MgSiF6. (NH4
)zsiF6.1lBP4. N1148F4 and N
aBF4 etc. All of these have a magnetic smoothing effect on grain-oriented silicon steel sheets with (110) planes after final annealing, but in the drying industry, they are used in consideration of prevention of metal precipitation on the cathode, etc. , it is desirable to choose from these. Further, its concentration is desirably 20 g/1 or more in order to maintain the electrical conductivity of the bath. Note that seawater can also be used in this invention due to its composition and concentration.

Water again? It is also advantageous to use baths in which polyether is further added to an aqueous solution containing a compatible halide. Here, polyether is a linear molecule containing an ether bond (-0-) in its main chain, and is generally a polymer compound formed by repeating carriers. Here, ¥1 usually represents a methylene group or a polymethylene group and its derivatives. For example, polyethylene glycol-ficlI□CIl□
Oh is one example.

The amount of polyether added here is 2 g/1. On the other hand, if the concentration is too high, the electrical conductivity of the bath will decrease, and the effect commensurate with the amount added cannot be expected, so a range of about 2 to 300 g/ff is appropriate. .

The bath temperature can be arbitrarily selected from room temperature or above, but if the temperature is too high, water will evaporate significantly, so room temperature to about 90°C is suitable. The current density ranges from about 5 A/dm2 to several hundred A/dm2.
dm". However, if the bath temperature is low and the current density is high enough to exceed 1.0 OA/dm2, it tends to cause uneven surface treatment, so if you try to widen the current density range, It is better to keep the bath temperature above 40°C.

In addition, from the viewpoint of reducing iron loss, the amount of electricity in electrolysis and the amount of electrolytic removal in this invention are each 300C/dm2.
Second, it is preferable that the thickness be 1μ or more per side.

As described above, in this invention, magnetic smoothing effects can be obtained under an extremely wide range of conditions compared to conventional methods, and this point is also advantageous for industrial implementation of this invention. This is one of the important roots of this.

Here, the changes in the bath caused by the electrolytic reaction are shown below, taking an NaCE aqueous solution as an example.

Anode: Fe-1-2C, C-→FeCff 2 +
2e-・-(1)] 6 Cathode: 2Na'+211zO+2e-->2NaO
1l-1-11□↑Haru: PeCj22+2NaO
II ->2NaCp! +Fe(Oll)z ↓ That is, FeCρ2 generated by the formula (1) and Na0II generated by the formula (2) automatically regenerate NaCj2 by the reaction shown in the formula (3). Therefore the bath f;
The control of the l-1 formation is basically based on the Fe generated using equation (3).
(Ko) Removal of the precipitate in step 2, replenishment of water, and preventing the steel plate from being taken out of the system! , which is much easier and lower cost than conventional chemical polishing or electrolytic polishing. This point is also one of the reasons why the method of this invention is industrially superior.

Next, the surface of the steel plate that has been magnetically smoothed according to the above process is subjected to treatments such as (1) removing a portion of the base metal, and (2) locally applying metal plating. Specifically, (1) Grinding methods such as scribing with a ballpoint pen or pen, or adding ultrasonic vibration, or non-contact high energy application to the steel plate such as laser or plasma irradiation. A means for adding "A" is advantageously suitable.

(2) A photoresist method in which plating is performed after photoresist, a masking method in which plating is performed after masking, or means such as screen printing or offset I□ printing using a paste-like plating agent are advantageously suitable.

Further, the state of existence of the bare metal removed part or the metal plating part is most advantageously perpendicular to the rolling direction, or may be diagonal or sinusoidal, and is preferably continuous or discontinuously linear. In addition, the width is preferably 0.1 to 0.4 mm, and the interval between bare metal removed parts or metal plated parts is 2.0 mm.
~10.0 mm is preferred.

After the above-mentioned anodic electrolysis in the halide aqueous solution is completed, the halide on the surface of the steel plate is washed away with water, and then an aqueous suspension or solution of hydrogen carbonate is applied to ensure the adhesion of the coating by surface cleaning. It is also effective to perform a brushing process using. Here, hydrogen carbonate means thorium hydrogen carbonate, ammonium hydrogen carbonate, potassium hydrogen carbonate, and the like. At this time, water/'J? P
j. It is desirable that the concentration be less than 10 g/ff, and if it is less than 10 g/p, the surface cleaning effect will not be sufficient.

The cleaning effect depends on the concentration, and is most noticeable when using a suspension, or when the concentration is 10 g/ff or more, a clear effect can be obtained compared to simple brushing treatment with water. As a brushing method, a brush made of synthetic fibers or natural fibers, a nonwoven fabric roll, etc. can be advantageously applied. After finishing the brush sink, wash it with water to fix it.
A cleaner surface is maintained with each drying.

Furthermore, the surface of a grain-oriented silicon steel sheet after anodic electrolysis in an aqueous halide solution is extremely active and therefore easily generates rust when exposed to the atmosphere.

The formation of rust causes deterioration of the appearance and subsequent deterioration of the adhesion of the coach ink, which in turn leads to deterioration of the magnetic properties. To prevent this, it is effective to add a corrosion inhibitor to the electrolytic bath. The types of inhibitors can be broadly classified into inorganic and organic (although they can be classified into several types, in this invention, any inhibitor may be used. Examples of inorganic inhibitors include chromates, nitrites, phosphates, etc.), and organic inhibitors. As the system, organic sulfur compounds and amines having a polar amino group (-Nlh) in the molecular structure can be used.

Since the degree of effectiveness varies depending on the type of inhibitor, it is difficult to say more about the concentration, or it is 0.1 to 50 g/i! The degree is appropriate.

Also, halide water/8? r9. When a grain-oriented silicon steel sheet is subjected to anodic electrolysis in the bath, a large amount of Fe(011)z precipitate is formed in the bath, and if the dirt exceeds about 2%, the viscosity of the solution increases too much and normal electrolysis is not carried out. It becomes possible.

In particular, when using an electrolytic solution containing an alkali metal halide as a main component, a certain amount of halogen ions are captured during the precipitation of Fe(Ollz), so that the bath pl+ shows a tendency to increase. If the electrolytic surface is exceeded, a uniform electrolytic surface will not be obtained.To prevent these problems from occurring,
It is effective to add a l+ buffer, or in other words, a clear-1 agent that converts Fe ions to clear-1. Phosphoric acid, citric acid, boric acid, acetic acid, glycine, maleic acid, etc., and their salts are effective as p++ buffering agents, and citric acid, tartaric acid, glycolic acid, etc. are effective as Fe ion kill-1 agents. Oxy acids, various amines, polyaminocarboxylic acids such as IEDTA, polyphosphates, etc. are effective. The amount of addition thereof is preferably in the range of approximately 1 to 100 g/2.

In addition, to prevent the rise in bath pl+ during electrolysis, it is also effective to oxidize the precipitate of Fe(OH)z in the bath to Fe(Oil)3. Air oxidation or 1120□ that forcibly strengthens the contact between
It is recommended to add oxides such as oxides to the bath.

After performing this series of treatments, a tension-applying coating is applied to the surface of the steel sheet in order to further improve the magnetic properties. The vibration coating may be a conventionally known phosphate-based coating containing colloidal silica, or may be formed by plating with 1'-ly or 2'-I.

That is, Ti, Nb, Si, V, and Cr are deposited by vapor deposition methods such as CVD methods and PVD methods (ion blating and ion implantation), or by plating.
AI MnB, Ni, Co, Mo, Zr+
Nitride and/or carbide of Ta, Iff, W and AI+! ;+, Mn, l'1g+ Zn,
An ultra-thin coating consisting mainly of at least one selected from Ti oxides is firmly formed on the surface of the steel sheet.

In addition to the materials listed above, the materials for such coatings include:
Any material may be used as long as it has a low coefficient of thermal expansion and firmly adheres to the steel plate.

Furthermore, if necessary, a tension-applied low-thermal-expansion top insulating film can be formed by a conventional method.

(Example) C: o, oa%, Si: 3.3%, Mn: 0.06%
, Se: 0.02%, and Sb: 0.022%. A hot rolled steel sheet having a composition containing 0.02% of Se and 0.022% of Sb was cold rolled twice including intermediate annealing to obtain a cold rolled sheet with a thickness of 0.23 mm. This steel plate was then subjected to decarburization and primary recrystallization annealing in wet hydrogen at 830"C, coated with an annealing separator containing A j2203 as the main component, wound into a coil, and then annealed at 850°. Secondary recrystallization annealing was performed at C for 50 hours and purification annealing was performed at 1200°C for 5 hours.

Thereafter, the unreacted annealing separator was removed, flattening annealing was performed to correct the winding of the coil, and a test material was obtained.

The oxide film on the surface of the test material was removed by pickling,
Then, after electrolytic treatment was performed in a chloride aqueous solution under the conditions shown in Table 1, the iron loss (L7zs.) was measured. Mirror polishing method using phosphoric acid and chromic acid for comparison (Comparative Example 8)
and i-machine polishing method (Emery #1.000 + Huff finish: Comparative Example 9).

After that, using an ultrasonic processing machine, the removed portion of the base iron is cut by 0.2
They were formed perpendicular to the rolling direction with a width of 4 mm and an interval of 4 mm.

Note that the vibrating body has a tip diameter of 1. Using a mm electrodeposited diamond rod, the vibration frequency was 30kllz, the vibration speed was
・The loaf was 40 μm. Next, a TiN film was deposited to a thickness of 1 μm by ion blating treatment, and after the TiN film was formed, strain relief annealing was performed at 800° C. for 2 hours.

Table 1 shows the results of N11l determination of iron loss at each stage.

As is clear from the same table, all of the conforming examples according to the present invention have a large improvement in iron loss, whereas the comparative example G, ) are all modified iron 11, ! It was only a small amount.

Disaster Scream 2-C: 0.058%, Si: 3.3%,
IO・008%, 810.025%, S:0.02%
and 0.008% of hot rolled steel sheet.
, : 1mm thick, cold rolled, transferred, decarburized annealed,
Then, after applying an annealing separator mainly composed of liver 0,
1-1 annealing is 119. I (, go up! I! 1st floor afterward)
i was ('117/!,. 105 i/kg.

KCp: 50 g/1. ．． 40'C]
In an aqueous solution, 75A/
Electrolytic treatment was carried out under the conditions of 3,000 corons/dm2 and 3,000 corons/dm2.
177.

=082 i/kg.

Next, as a vibrating body ☆: 1 with an angle of 11 or 60°
I used a square cylinder of #1000 Yakuten and Earmont of 8 man, and the frequency was 25ktl? , Vibration switch] - 20/1 m, width 0.3 mm, interval 3 mm, 171 degrees with the rolling direction + 1 [].

A cotton-like base iron removed portion was formed. The iron loss at this time is W
+775o=0.75W/kg.

Furthermore, when the Si3N4 film was coated with ion blating treatment (1 μm thick), the iron loss was W+7/
It was reduced to 5o=0.65W/kg.

Next, 800'C: 3 hours of strain relief grilling 111! However, the iron loss was 0.64ty/kg, which was 0.64ty/kg.

Sharpness C: 0.045%, Si: 3.25%, Mn
: 0.072%, SeO, 01.9% and Sb
: A hot-rolled steel sheet having a composition containing 0.020% was cold-rolled twice including intermediate annealing to obtain a cold-rolled sheet with a thickness of 0.23 mm. This steel plate was then subjected to decarburization and primary recrystallization annealing in wet hydrogen at 830°C, coated with an annealing separator containing A E 203 as a main component, and wound into a coil shape. Secondary recrystallization annealing for 50 hours at 'C and 12
Purification annealing was performed at 00°C for 5 hours.

Thereafter, the unreacted annealing separator was removed, flattening annealing was performed to straighten the winding edge of the coil, and a test material was obtained.

The oxide film on the surface of the test material was removed by pickling,
Then, after performing electrolytic treatment in a chloride aqueous solution under the conditions shown in Table 2, the iron loss (L7zso) was measured. Mirror polishing method using phosphoric acid and chromic acid for comparison (Comparative Example 6)
and a mechanical polishing method (Emery 41000+Hough finish: Comparative Example 7).

After that, IOA/d was applied using a photoresist method in a T#rLt bath (nickel sulfate 240 g/42, nickel chloride 45 g/ff, boric acid 30 g/ffi, temperature 60°C).
N1 coating was applied for 10 seconds at a current density of mt.

Then, the TiN film was formed to a thickness of 1 μm by ion blating treatment.
After the TiN film was formed, strain relief annealing was performed at 800° C. for 2 hours. Table 2 shows the measurement results of iron loss at each stage.

27~ As is clear from the same table, all of the conforming examples obtained according to the present invention have a large degree of improvement in iron loss (on the other hand, all of the comparative examples have only a slight improvement in iron loss. It was just that.

Fruit split 1 C: 0.057%, Si: 3.3%, Mn: 0.
A hot rolled steel plate containing 0.08%, 5O302%, Aj2: 0.025% and N: 0.008% was heated to 0.3%.
0mmJ! After cold rolling to 7-, subjected to IIQ charcoal sintering, and then applied to M with an annealing disrupter mainly composed of o,
Finish annealing was performed. Iron loss after finish annealing is W+7zs
There was 84g of o-1,04W. After removing the Forsterei I coating on the surface of the Saramuko steel plate by pickling, KCf! A
50 g, /I1. ．． Test in aqueous solution at 40°C (7)
1008/dm2.3000C/dm2 with No. as anode
Article 1-1 Lower G trowel electrolytic treatment was performed. Obtained steel plate iron 11) Chopper I+7z5o-0,8! J/kg.

Furthermore, by masking method, Sn plating was applied to 0.25mm.
The plating was applied perpendicularly to the rolling direction with a width and thickness of 0.002 mm, and an interval of 8 mm between the plated parts. The iron weight at this time was 匈 (7/5 o - 0.7 ham g).

Furthermore, when a tension-imparting coating film with a composition of colloidal silica-magnesium phosphate chromic acid anhydride was formed, the iron loss was W17zso=0.69t'l/kg.
It was reduced to

Next, strain relief annealing was performed at 800°C for 3 hours, but the iron loss was 1. /,. There was no deterioration at -0.69 Ill/kg.

C: 0.042%, Si: 3.20%, Mn
: 0.068%, Se: 0.017% and S
b: A hot rolled steel sheet having a composition containing 0.019% is cold rolled twice including intermediate annealing to a thickness of 0.20 mm.
It was made into a thick cold-rolled plate. This steel plate was then subjected to decarburization and primary recrystallization annealing in wet hydrogen at 830°C.
After applying an annealing separator mainly composed of , it was wound into a coil shape and subjected to secondary recrystallization annealing at 850°C for 50 hours and purification annealing at 1200°C for 5 hours.

Thereafter, the unreacted annealing separator was removed, and flattening annealing was performed to force the winding of the coil to form a test material.

The oxide film on the surface of the test material was removed by pickling,
Then, after electrolytic treatment was performed in an aqueous solution under the conditions shown in Table 3, the iron loss (W+7zso) was measured. For comparison, a mirror polishing method using phosphoric acid and chromic acid (Comparative Example 8) and a mechanical polishing method (Eme IJ-# 1.000 ten-hough finish:
Comparative Example 9) was conducted.

After that, using an ultrasonic processing machine, the removed portion of the base iron is 0.0
They were formed perpendicular to the rolling direction with a width of 5 mm and an interval of 5 mm.

As the vibrating body, a needle electrodeposited with diamond having a tip diameter of 0.8 mm was used, and the vibration frequency was 20 kllz and the vibration stroke was 10 μm. Then, a TiN film was deposited to a thickness of 0.971 m by ion blating treatment. T
After the iN deposition, strain relief annealing was performed at 800°C for 3 hours.

Table 3 shows the measurement results of iron loss at each stage.

(Effects of the Invention) Thus, according to the present invention, it is possible to stably and inexpensively obtain a grain-oriented silicon steel sheet that has extremely low iron loss, and in particular does not deteriorate in iron loss even after strain relief annealing.

[Brief explanation of the drawings] Figures 1 (a) and (b) are graphs showing the improvement in iron loss of silicon steel sheets treated according to the present invention. Figure 2 is a metal structure showing crystal planes with different orientations. It's a photo. Patent ('') Applicant Kawasaki Steel Corporation

Claims (1)

[Claims] 1. A grain-oriented silicon steel sheet that has been finish annealed is subjected to magnetic smoothing treatment by electrolysis in an aqueous solution containing one or more water-soluble halides, and then one of the base irons on the surface of the steel sheet is smoothed. Strain relief annealing, which is characterized by removing parts in a continuous or discontinuous line extending across the rolling direction and then forming a tension-applying insulating film on the surface of the steel sheet, results in a low core loss direction in which the characteristics do not deteriorate. manufacturing method of silicon steel sheet. 2. A finish-annealed grain-oriented silicon steel sheet is subjected to magnetic smoothing treatment by electrolysis in an aqueous solution containing one or more water-soluble halides, and then a continuous or intermittent pattern extending across the rolling direction is applied to the surface of the steel sheet. A method for producing a grain-oriented silicon steel sheet with low iron loss whose properties do not deteriorate due to strain relief annealing, the method comprising applying linear metal plating and then forming a tension-applying insulating film on the surface of the steel sheet.