Technical field
[0001]The present invention, grain-oriented electrical steel sheet used as an iron core material of a transformer, in particular, excellent in adhesion tension insulating coating, to an amorphous oxide film having a directional magnetic steel sheet.
　The present application, to 07 May 13, 2017, claiming priority based on Japanese Patent Application No. 2017-137408, filed in Japan, the contents of which are incorporated here.
BACKGROUND
[0002]
　Oriented electrical steel sheet is mainly used in the transformer. Transformer is continuously energized for a long period of time to disposal from installation, it continues to generate the energy loss. Therefore, energy loss when it is magnetized by an alternating current, i.e., the iron loss, the key indicators in determining the performance of the transformer.
[0003]
　To reduce iron loss oriented electrical steel sheet, (a) {110} <001> increase the integration of the orientation (Goss orientation), of steel sheet by increasing the content of solid solution elements such as (b) Si increasing the electrical resistance, or, in terms of, thinning the thickness of the (c) electrical steel sheet, heretofore, many techniques have been developed.
[0004]
　Further, it is effective in reducing the iron loss to impart tension to the steel sheet. Thermal expansion coefficient of the small material of the coating from the steel sheet at a high temperature, can be formed on the surface of the steel sheet is an effective means for reducing iron loss. In the finish annealing step of the electromagnetic steel sheet, oxides and annealing separating agent surface of the steel sheet is produced by the reaction, forsterite film excellent in coating adhesion is a coating which can impart tension to the steel sheet.
[0005]
　For example, it disclosed in Patent Document 1, a coating liquid composed mainly of colloidal silica and phosphate, a method of forming an insulating film by baking the surface of the steel sheet has a large effect of tensioning of the steel sheet, iron it is an effective method to reduce the loss. Therefore, leaving the forsterite film generated in the finish annealing step, thereon, be subjected to insulating coating mainly comprising phosphate, and has a production method of common grain-oriented electrical steel sheet.
[0006]
　However, in recent years, forsterite coating hinder domain wall motion, it became clear that an adverse effect on iron loss. In the grain-oriented electrical steel sheet, magnetic domain, magnetic domain walls under alternating magnetic field is changed by moving. It movement of the domain wall is smoothly and quickly found is effective in reducing the iron loss, forsterite film has an uneven structure on the steel / coating interface, the uneven structure prevents the movement of the domain wall because, it believed to adversely affect the iron loss.
[0007]
　Therefore, to suppress the formation of forsterite coating, a technique for smoothing the surface of the steel sheet has been studied. For example, Patent Documents 2-5 control the dew point of the decarburization annealing, by using alumina as an annealing separating agent, without forming a forsterite coating in finish annealing, a technique for smoothing the surface of the steel sheet It has been disclosed.
[0008]
　However, when the smoothed surface of the steel sheet in this manner, in order to impart tension to the steel sheet, the steel sheet surface, it is necessary to form a tension insulating film having a sufficient adhesion.
　For such problems, Patent Document 6, after forming the amorphous oxide film on the surface of the steel sheet, a method of forming a tension insulating film is disclosed. Patent Document 7 to 11, aimed at further adhesion to form a high tension insulating film, a technique for controlling the structure of the amorphous oxide film is disclosed.
[0009]
　Patent Document 7 discloses a method of securing the coating adhesion to the tension insulating film and the steel sheet is disclosed. In this way, the surface of the grain-oriented electrical steel sheet of the steel sheet surface was smoothed, was subjected to a treatment prior to introduction of the fine irregularities, to form external oxidation type oxide, further through the thickness of the external oxide film in form, by forming a particulate external oxide based on silica, it has secured coating adhesion.
[0010]
　Patent Document 8, a method of securing the coating adhesion to the tension insulating film and the steel sheet is disclosed. In this way, in the heat treatment step of forming an external oxidation type oxide film to the surface of the steel sheet grain-oriented electrical steel sheet obtained by smoothing, the heating rate of the temperature range of 200 ° C. or higher 1150 ° C. or less 10 ° C. / sec or higher 500 ° C. / s is controlled to below the iron to total external oxide film, aluminum, titanium, manganese, a cross-section area of ​​the metal-based oxide such as chromium by 50% or less, the coating adhesion to the tension insulating film and the steel sheet It is secured.
[0011]
　Patent Document 9, a method of securing the coating adhesion to the tension insulating film and the steel sheet is disclosed. In this way, the steel sheet surface to form external oxidation type oxide film on the grain-oriented electrical steel sheet smoothed, followed by the tension insulating film forming step, coating the steel sheet and the tension insulating film formed external oxide type oxide film is formed by the contact time between the liquid below 20 seconds, the ratio of the density reduction layer in the outer oxidized oxide film to 30% or less so as to ensure a coating adhesion to the tension insulating film and the steel sheet.
[0012]
　Patent Document 10, a method of securing the coating adhesion to the tension insulating film and the steel sheet is disclosed. In this method, carried out at temperatures above 1000 ° C. The heat treatment for forming the external oxidation type oxide film to the surface of the steel sheet grain-oriented electrical steel sheet obtained by smoothing the temperature of the formation temperature of the external oxide type oxide film to 200 ° C. controlling the cooling rate of the band below 100 ° C. / sec, is set to lower than or equal to 30% a cavity in the outer oxide type oxide film in cross section area ratio so as to ensure a coating adhesion to the tension insulating film and the steel sheet .
[0013]
　Patent Document 11, a method of securing the coating adhesion to the tension insulating film and the steel sheet is disclosed. In this way, in the heat treatment step of forming an external oxidation type oxide film to the surface of the steel sheet grain-oriented electrical steel sheet obtained by smoothing, the heat treatment temperature 600 ° C. or higher 1150 ° C. or less, the dew point to -20 ° C. or higher 0 ℃ less in conditions, and, by annealing, thereby containing 5% to 30% or less of the metal iron sectional area ratio in the outer oxide type oxide film under conditions in which the cooling dew point at that time with 5 ° C. or higher 60 ° C. or less, It has secured coating adhesion to the tension insulating film and the steel sheet.
[0014]
　However, in any of the methods disclosed in Patent Documents 7 to 11, can not be obtained sufficient adhesion between the tension insulating film and the steel sheet, there is a case where the iron loss reducing effect as expected can not sufficiently exhibited.
CITATION
Patent Document
[0015]
Patent Document 1: Japanese Sho 48-039338 Patent Publication
Patent Document 2: Japanese Patent Laid-Open 07-278670 discloses
Patent Document 3: Japanese Patent Laid-Open 11-106827 discloses
Patent Document 4: Japanese Patent 11- 118750 JP
Patent Document 5: Japanese Patent 2003-268450 JP
Patent Document 6: Japanese Patent Laid-Open 07-278833 discloses
Patent Document 7: Japanese Patent 2002-322566 JP
Patent Document 8: Japanese Patent 2002-348643 JP
Patent Document 9: Japanese Patent 2003-293149 JP
Patent Document 10: Japanese Patent 2002-363763 JP
Patent Document 11: Japanese Patent 2003-313644 JP
Summary of the Invention
Problems that the Invention is to Solve
[0016]
　In view of the state of the prior art, in order to significantly reduce iron loss, when covering the tension insulating film on the surface of a grain-oriented electromagnetic steel sheet has no forsterite coating on the steel sheet surface, the tension insulating film and the steel sheet it is an object to enhance the adhesion between the. That is, the present invention aims to provide a grain-oriented electrical steel sheet excellent in adhesiveness to the tension insulating film.
Means for Solving the Problems
[0017]
　The present inventors have intensively studied a technique for solving the above problems. As a result, you can remove the forsterite film, or, obtained by or intentionally prevent the formation of forsterite on the surface of the steel sheet having no forsterite film on the steel sheet surface after film formation gloss of steel plate is by forming an amorphous oxide coating such that 150% or more was found that the adhesion between the tension insulating film and the steel sheet is remarkably improved.
[0018]
　The present invention has been made based on the above findings and has as its gist is as follows.
[0019]
(1) grain-oriented electrical steel sheet according to an embodiment of the present invention includes a steel sheet, and the amorphous oxide film formed on the steel sheet, the glossiness of the surface is 150% or more.
[0020]
[Correction under Rule 91　
10.09.2019] The oriented electrical steel sheet according to (2) above (1), wherein the steel sheet, as a chemical composition, in mass%, C: 0.085% or less, Si: 0. 80 ~ 7.00%, Mn: 1.00 % or less, Al: 0.065% or less, S: 0.013% or less, Cu: 0 ~ 0.80%, N: 0 ~ 0.012%, P : 0 ~ 0.5%, Ni: 0 ~ 1.0%, Sn: 0 ~ 0.3%, Sb: 0 ~ 0.3%, containing the balance may consist of Fe and impurities.
[0021]
(3) oriented electrical steel sheet according to the above (2), the steel sheet, as the chemical composition, by mass%, Cu: may contain 0.01 to 0.80%.
[0022]
(4) above (1) oriented electrical steel sheet according to any one of the - (3), the glossiness may be a glossiness measured by the method described in JIS Z-8741.
The invention's effect
[0023]
　According to this aspect of the present invention, it is possible to provide an oriented electrical steel sheet excellent in adhesion to the tension insulating film and the steel sheet.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024]
It is a diagram showing a relationship between [1] gloss and the coating residual area ratio.
2 is a diagram showing the relationship between the oxygen partial pressure and the glossiness of the annealing atmosphere to form an amorphous oxide film.
DESCRIPTION OF THE INVENTION
[0025]
　Oriented electrical steel sheet according to an embodiment of the present invention (hereinafter sometimes referred to as "electromagnetic steel sheet according to the present embodiment".) Is, in the grain-oriented electrical steel sheet having an amorphous oxide film on the surface of the steel sheet, the surface of the glossiness and wherein the at least 150%. In other words, grain-oriented electrical steel sheet according to the present embodiment, steel plate and has a, an amorphous oxide film formed on the steel sheet, and wherein the surface glossiness is 150% or more to.
[0026]
　The following describes an electromagnetic steel sheet according to the present embodiment.
[0027]
　The present inventors have found that no steel sheet surface forsterite coating, in the case of coating the tension insulating coating to reduce iron loss, was examined how to ensure the coating adhesion tension insulating coating. As a result, the surface of the steel sheet has no forsterite coating, in terms of (the amorphous oxide film formed so as to be in direct contact with the surface of the particular steel sheet) was amorphous oxide film formed covering the surface of the steel sheet, the morphology of the amorphous oxide film was uniform and idea that it is important that as much as possible to suppress the stress concentration at the interface between the tension insulating film and the steel sheet. Steel no forsterite coating, or to remove the forsterite coating after finish annealing, or it can be formed by intentionally prevent the formation of forsterite. For example, by adjusting the composition of the annealing separator, it is possible to intentionally prevent the formation of forsterite.
[0028]
　As described above, the surface of the forsterite coating is not steel (base steel sheet), after forming the amorphous oxide film, by uniform morphology of the amorphous oxide film, the a tension insulating film formed on the upper, would be able to enhance the adhesion between the steel sheet. However, very thin about several nm thickness of the amorphous oxide, it is extremely difficult to determine whether the morphology is uniform. Accordingly, the present inventors have studied a method to evaluate the uniformity of the morphology of the amorphous oxide film. As a result, by using the glossiness of the steel sheet surface with an amorphous oxide film was found to be able to evaluate the uniformity of the morphology of the amorphous oxide film. That is, the higher the glossiness of the steel sheet surface, it was found that the morphology of the amorphous oxide film coating the steel sheet surface is uniform.
[0029]
　Based on the above idea, the present inventors have conducted the following experiment, the relationship between the glossiness of the steel sheet surface oriented electrical steel sheet having adhesion tension insulating film (the film adhesion) of the amorphous oxide film investigated.
[0030]
　As experimental material, the decarburization annealed sheet of thickness 0.23mm comprising Si 3.4%, performed finish annealing by applying an annealing separator consisting mainly of alumina, by secondary recrystallization, folders It was prepared oriented electrical steel sheet having no stellite-based film. This grain-oriented electrical steel sheet, 25% of nitrogen, hydrogen 75%, in an atmosphere of a dew point -30 ° C. ~ 5 ° C., subjected to a heat treatment of soaking time 10 seconds, the steel sheet surface, silica (SiO 2 Non mainly of) to form an amorphous oxide film.
[0031]
　The gloss of the surface of the grain oriented electrical steel sheet having an amorphous oxide film, JIS Z-8741 standardized the method (black glass standard plate at an incident angle of 60 ° (refractive index 1.567) were measured value as the 100 was measured by the method) for defining a gloss.
　Then, the surface of the grain-oriented electrical steel sheet having an amorphous oxide film, a phosphate, chromic acid, a coating solution composed mainly of colloidal silica was coated, in a nitrogen atmosphere, and baked for 30 seconds at 835 ° C., to form a tension insulating film.
[0032]
　In this way the tension insulating film having a directional electromagnetic steel sheet which is manufactured to investigate the coating adhesion tension insulating coating.
　Coating adhesion tension insulating coating, the cylindrical diameter 20 mm, after winding the samples taken from the steel sheet (180 ° bending), in a state where the bent back, or the tension insulating film is not peeled off from the steel plate, in close contact area ratio of residual to that portion (hereinafter referred to as "film remaining area ratio".) were evaluated in. The coating remaining area ratio may be determined visually.
[0033]
　Figure 1 shows the relationship between the glossiness and the film remaining area ratio. From Figure 1, when obtaining the condition which can ensure coating adhesion tension insulating film as follows.
[0034]
　(I) gloss at 150% or more, the film residual area ratio is 80% or more, the coating adhesion tension insulating film is good.
[0035]
　(Ii) gloss at 230% or more, the film residual area ratio is 90% or more, the coating adhesion tension insulating coating is better.
[0036]
　Based on the above results, the electromagnetic steel sheet according to the present embodiment, and an amorphous oxide film formed on the surface of the steel sheets, the surface of the grain-oriented electrical steel sheet having an amorphous oxide film the gloss is defined to be 150% or more. Glossiness is preferably 230% or more.
[0037]
　Here, amorphous and is not made of atoms or molecules regular spatial grid, a solid has a sequence disturbed. More specifically, when subjected to X-ray diffraction, only a halo was detected, indicating the state in which the specific peak is not detected.
　The electromagnetic steel sheet according to the present embodiment, the amorphous oxide film, a film composed of substantially only amorphous oxide. Coating Whether an oxide can be confirmed using TEM and FT-IR.
[0038]
　Gloss can be measured by the following method.
　Commercial gloss meter, for example by using BYK-Gardner Co. micro tri gloss gloss meter (4446), JIS Z-8741 black glass standard plate by the standard method (incident angle 60 ° to the (refractive index 1.567) the measured value 100, measured by the method) defining a gloss.
　If the tension insulating film is formed on the amorphous oxide film, the tension insulating film of product steel sheets to form a tension insulating coating, is immersed in an etching solution of 20% sodium hydroxide 80 ° C. 20 min wet after selectively removed by etching, it may be measured gloss.
[0039]
　In terms of ensuring the uniformity of the morphology of the amorphous oxide film, the amorphous oxide film is preferably amorphous oxide film of an external oxidation type.
[0040]
　The surface of the steel sheet, rather than the external oxidation type, the case of forming the amorphous oxide film of the internal oxidized, tension insulating film and the amorphous oxide as a starting point in some cases peeled off. Here, the amorphous oxide film of the internal oxidized at the interface of the steel sheet and the amorphous oxide, that of the amorphous oxide film in a state in which the amorphous oxide is recessed inside the steel sheet There, the amorphous oxide is a ratio of the length aspect ratio is 1.2 or more of the base length and invagination of the depth of the invaginations is defined as an amorphous oxide of internal oxidation type .
[0041]
　The glossiness of the steel sheet surface, the steel sheet composition of (base steel sheet) directly, does not affect, the electromagnetic steel sheet according to the present embodiment, the component composition (chemical of a steel sheet for forming the amorphous oxide film composition) is not especially limited. However, after forming an amorphous oxide film and / or tension insulating film on the surface, the case of obtaining a desirable characteristic of the grain-oriented electrical steel sheet is preferably in the following ranges. Hereinafter,% of the component composition refers to mass%.
[0042]
　C: 0.085% or less
　C is an element which remarkably deteriorates the iron loss property by magnetic aging. When C content exceeds 0.085% after decarburization annealing also, C is residual iron loss characteristics deteriorate. Therefore, C content is at most 0.085%. C is preferred for iron loss as small, the detection limit is about 0.0001%, 0.0001%, which is substantially the lower the C content. In terms of iron loss improvement, C content is preferably 0.010% or less, more preferably 0.005% or less.
[0043]
　Si: 0.80 ~
　7.00% Si is an element contributing to the improvement of magnetic properties. The Si content is less than 0.80%, the steel is transformed phase during the secondary recrystallization annealing can not control the secondary recrystallization, is not good magnetic flux density and the iron loss characteristics. Therefore, Si content is 0.80% or more. Preferably 2.50% or more, and more preferably not less than 3.00%.
[0044]
　On the other hand, when the Si content exceeds 7.00%, the steel sheet is embrittled, sheet passing property in the manufacturing process is significantly deteriorated. Therefore, Si content is at most 7.00%. Preferably not more than 4.00%, more preferably not more than 3.75%.
[0045]
　Mn: 1.00% or less
　Mn content exceeds 1.00%, the steel is transformed phase during the secondary recrystallization annealing, and can not be obtained good magnetic flux density and iron loss characteristics. Therefore, Mn content is at most 1.00%. Preferably 0.70% or less, more preferably 0.50% or less. Al content may be 0%.
[0046]
　Meanwhile, Mn is an austenite-promoting elements. The Mn content is less than 0.01%, the effect is not sufficiently obtained, also, the steel sheet becomes brittle during hot rolling. Therefore, Mn content may be 0.01% or more. Preferably 0.05% or more, more preferably 0.10% or more.
[0047]
　Al: 0.065% or less
　When the Al content exceeds 0.065%, the steel sheet becomes brittle, AlN precipitation becomes non-uniform. As a result, the required secondary recrystallized structure can not be obtained, the magnetic flux density decreases. Therefore, Al content is made 0.065% or less. Preferably 0.060% or less, and more preferably not more than 0.055%. Al content may be 0%.
　Meanwhile, Al forms an AlN that functions as inhibitor, an element which contributes to the improvement of the magnetic properties. Therefore, in the slab used in the manufacturing, the Al content is less than 0.010%, less the amount of AlN, secondary recrystallization does not proceed sufficiently. Therefore, Al content in the slab used for fabrication is preferably set to 0.010% or more, the Al may remain in the steel sheet.
[0048]
　S: 0.013% or less
　S forms fine sulfides, is an element to reduce the iron loss characteristics. S is preferably as small, the detection limit is about 0.0001%, S content may be 0.0001% or more. More preferably 0.003% or more, further preferably 0.005% or more.
[0049]
　On the other hand, when the S content exceeds 0.013% iron loss is significantly reduced. Therefore, S content is at most 0.013%. Preferably 0.010% or less, more preferably 0.005% or less.
[0050]
　Electrical steel sheet according to the present embodiment, the balance excluding the element is a basic that the Fe and impurities, in addition to the above elements, the Cu, in order to improve the magnetic properties, and contained in the following ranges it may be. Since Cu is not necessarily contained, the lower limit is 0%.
[0051]
　Cu: 0 ~
　0.80% Cu combines with S, is an element which forms a precipitate that acts as an inhibitor. The Cu content is less than 0.01%, the effect is not sufficiently obtained by containing, if to obtain the effect, the Cu content is preferably 0.01% or more. More preferably 0.04% or more, further preferably 0.08% or more.
[0052]
　On the other hand, when the Cu content exceeds 0.80% dispersion of precipitates becomes inhomogeneous, the iron loss reducing effect is saturated. Therefore, even if to be contained, Cu content is 0.80%. Preferably 0.60% or less, more preferably 0.50% or less.
[0053]
　Further, the above-mentioned composition of ingredients, within a range that does not impair the properties of the electrical steel sheet according to the present embodiment, N, P, Ni, Sn, may be contained in a range of one or more of Sb. These elements may not necessarily contain a lower limit is 0%.
[0054]
　N: 0 ~ 0.012%
　N is an element to form AlN that functions as inhibitor. The N content is less than 0.004% or, since the formation of AlN becomes insufficient, the case of obtaining the above effect, N content is preferably 0.004% or more. More preferably 0.006% or more, further preferably 0.007% or more.
[0055]
　Meanwhile, N is the, cold rolling is also an element forming a blister (holes) in the steel sheet. When N content exceeds 0.012% cold rolling, there is a fear of generating blister (holes) in the steel sheet, even if to be contained, N content is at most 0.012%. N content is preferably 0.010% or less, and more preferably not more than 0.009%.
[0056]
　P: 0 ~ 0.50%
　P is raising the specific resistivity of the steel sheet, an element which contributes to the reduction of iron loss. In order to obtain the effect of containing reliably, it is preferable that the P content be 0.02% or more.
　On the other hand, when the P content exceeds 0.50%, the rolling resistance decreases. Therefore, even if to be contained, P content is at most 0.50%. Preferably not more than 0.35%.
[0057]
　Ni: 0 ~ 1.00% Ni
　is raising the specific resistivity of the steel sheet, contributes to the reduction of iron loss by controlling the metal structure of the hot-rolled steel sheet, which is an element contributing to the improvement of the magnetic properties. When to reliably obtain the effect of containing, it is preferable that the Ni content is 0.02% or more.
　On the other hand, when the Ni content exceeds 1.00%, secondary recrystallization proceeds unstable. Therefore, even if to be contained, Ni is not more than 1.00%. Ni content is preferably 0.25% or less.
[0058]
　Sn:
　0 ~ 0.30% Sb: 0 ~
　0.30% Sn and Sb segregates at grain boundaries, the finish annealing, the annealing separator agent Al is oxidized by moisture release (in this oxidation, different inhibitor strength at the coil location, an element having an effect of preventing the magnetic characteristics fluctuate) to. In order to obtain the effect of containing the certainty, in any of the elements, preferably the content is 0.02% or more.
　On the other hand, the amount contain any of the elements is more than 0.30%, the secondary recrystallization becomes unstable, the magnetic characteristics are deteriorated. Therefore, none of Sn and Sb to the content 0.30% or less. Preferably, each element also below 0.25%.
[0059]
　That is, the electromagnetic steel sheet according to the present embodiment includes the above elements, the balance being Fe and impurities.
　Steel sheet having such a chemical composition, C: 0.085% or less, Si: 0.80 ~ 7.00%, Mn: 0.01 ~ 1.00%, Al: 0.010 ~ 0.065% , S: 0.001 ~ 0.013%, Cu: 0 ~ 0.01 ~ 0.80%, N: 0 ~ 0.012%, P: 0 ~ 0.50%, Ni: 0 ~ 1.00 %, Sn: 0 ~ 0.30% , Sb: 0 ~ 0.30%, and contains the balance can be obtained by manufacturing using a slab consisting of Fe and impurities.
[0060]
　Then the preferred method of manufacturing the electrical steel sheet according to this embodiment will be described.
[0061]
　The molten steel was adjusted to the required chemical composition, conventional methods (for example, continuous casting) to manufacture a slab for grain oriented electrical steel sheet manufactured by casting in. Then subjected to the slab to the normal hot rolling, the hot-rolled steel sheet, the hot rolled coil by winding the hot-rolled steel sheet. Then, rewind the hot rolled coil, subjected to hot rolled sheet annealing, then one cold rolling, or is subjected to a plurality of cold rolling sandwiching the intermediate annealing, the same thickness of the final product and steel plate. Subjected to a decarburization annealing the steel sheet after cold rolling.
[0062]
　Decarburization annealing, it is preferable to heat in a wet hydrogen atmosphere. By performing the decarburization annealing in the atmosphere, the C content in the steel sheet, while reducing to a region deterioration does not occur in the magnetic characteristics due to magnetic aging in the product steel sheet can be primary recrystallization. This primary recrystallization, the preparation of secondary recrystallization.
[0063]
　After decarburization annealing, the steel sheet in an ammonia atmosphere annealed to produce an AlN inhibitor in the steel sheet.
[0064]
　Subsequently, steel sheets, subjected to finish annealing at 1100 ° C. or higher. Finish annealing may be performed under the form of a coil was wound steel, the surface of the steel sheet for the purpose of seizure prevention of the steel plate, Al 2 O 3 carried out after applying an annealing separator composed mainly of.
[0065]
　After finish annealing finished, using a scrubber, to remove the excess annealing separator, a steel plate, to control the surface state of the steel sheet. If the removal of excess annealing separator, together with the processing by the scrubber, it is preferable to carry out rinsing.
　Scrubber, the thread diameter of the brush, it is preferable that the diameter 0.2 mm ~ 0.6 mm. Thread diameter of the brush is, in the case of 0.6mm greater than rough surface of the steel sheet (roughness becomes large), the gloss after the amorphous oxide film formation is lowered, unfavorably. On the other hand, the yarn diameter of the brush is less than 0.2 mm, the removal of excess annealing separator is not sufficient, since the gloss after the amorphous oxide film formation is low, such being undesirable.
　After annealing separator is removed by scrubbing, the (arithmetic mean Ra of JISB0601) surface roughness of the steel sheet, preferably about 0.2 ~ 0.6 .mu.m.
[0066]
　Then, the steel sheet, the oxygen partial pressure (P H2 O / P H2 ) annealed in a mixed atmosphere of adjusting hydrogen and nitrogen, to form an amorphous oxide film on the surface of the steel sheet.
　As described above, the gloss of the surface (due to the uniformity of the morphology of the amorphous oxide film) affects the coating remaining area ratio (indicator of coating adhesion quality of the tension insulating film). The present inventors have found that with respect to steel sheet after finish annealing, the oxygen partial pressure in the annealing atmosphere at the time of forming the amorphous oxide film (P H2 O / P H2 by changing), the oxygen partial pressure in the annealing atmosphere ( P H2O / P H2 ) and was investigated the relationship between the gloss.
[0067]
　Figure 2 shows the relationship between the oxygen partial pressure and the glossiness of the annealing atmosphere to form an amorphous oxide film was obtained. 2, in the evaluation of coating film adhesion, the case coating remaining area ratio of above 90% indicated by ○ in the figure, the film residual area ratio indicates a case of 80% or more and less than 90% △, coating remaining area rate showed a case of less than 80% ×.
[0068]
　From Figure 2, the oxygen partial pressure of the annealing atmosphere to form an amorphous oxide film as the glossiness of 150% or more (P H2 O / P H2 ) is 0.010 or less, amorphous to be a gloss 230% or more an oxygen partial pressure of the annealing atmosphere to form the quality oxide film (P H2 O / P H2 ) is 0.005 or less, further, to form an amorphous oxide film as the surface glossiness 250% or more annealing the partial pressure of oxygen in the atmosphere (P H2 O / P H2 ) is seen to be 0.001 or less.
　Therefore, when obtaining an electromagnetic steel sheet according to the present embodiment, the oxygen partial pressure in the annealing atmosphere to form an amorphous oxide film (P H2 O / P H2 ) is preferably set to 0.010 or less, 0.005 or less more preferably to, and even more preferably from 0.001 or less.
[0069]
　In annealing for forming the amorphous oxide film, the annealing temperature is preferably 600 ~ 1150 ° C., more preferably 700 ~ 900 ° C..
　Is less than the annealing temperature of 600 ° C., the amorphous oxide film is not sufficiently generated. In addition, it is not preferable because the equipment load is higher in 1150 ℃ than.
[0070]
　In annealing for forming the amorphous oxide film, the cooling rate after annealing may not be limited to, the amorphous oxide film of the aspect ratio of the amorphous oxide is an external oxidation type less than 1.2 in order to control that the morphology uniform, the oxygen partial pressure in annealing cooling (P H2 O / P H2 it is preferable to set) to 0.005 or less.
[0071]
　Thus, it is possible to obtain an amorphous oxide film having a directional electromagnetic steel sheet coating adhesion tension insulating film is good.
Example
[0072]
　Next, a description will be given of an embodiment of the present invention, conditions in examples are an example of conditions adopted for confirming the workability and effects of the present invention, the present invention is, in this single condition example the present invention is not limited. The present invention does not depart from the gist of the present invention, as long as they achieve the object of the present invention may employ various conditions.
[0073]
　(Example)
　The silicon steel slab of chemical composition shown in Table 1-1 (steel No. A ~ F), respectively, were subjected to hot rolling by heating to 1100 ° C., and hot-rolled steel sheet having a thickness of 2.6mm did. Annealed at 1100 ° C. These hot-rolled steel sheet, then subjected to several times of cold rolling sandwiching the single cold rolling or intermediate annealing, and cold-rolled steel sheet of the final sheet thickness 0.23 mm. Thereafter, these cold-rolled steel sheet was subjected to decarburization annealing and nitriding annealing.
[0074]
[Table 1-1]

[0075]
[Table 1-2]

[0076]
　Then, the cold-rolled steel sheet was subjected to a decarburization annealing and nitriding annealing, an aqueous slurry of an annealing separator composed mainly of alumina was applied, 1200 ° C., complete subjected to secondary recrystallization finish annealing of 20 hours is, no forsterite film on the steel sheet surface, having a specular gloss was obtained oriented electrical steel sheet. Before finish annealing was carried out and the control of the removal and surface conditions of the annealing separator according scrubber under the conditions shown in Table 2. At that time, when the yarn diameter of the scrubber and 0.2 ~ 0.6 .mu.m, the surface roughness of the steel sheet (arithmetic mean Ra of JISB0601) was about 0.3 ~ 0.4 .mu.m. In addition, analysis of the components of the steel sheet after final annealing were as shown in Table 1-2.
[0077]
　This grain-oriented electrical steel sheet consists of 25% nitrogen and hydrogen 75%, production conditions shown in Table 2 No. Such as 1 to 17, in an atmosphere of oxygen partial pressure, subjected to a soaking treatment (annealing) at a holding temperature shown in Table 2, then consists of 25% nitrogen and hydrogen 75%, the oxygen partial pressure shown in Table 2 atmosphere, was subjected to heat treatment to cool to room temperature. If the holding temperature of annealing was 600 ° C. or higher, the coating is formed on the surface of the steel sheet.
[0078]
　Film formed on the surface of the steel sheet is whether an even amorphous oxide film, X-rays diffraction and was confirmed using TEM. In addition, confirmation was also carried out using FT-IR together.
　Specifically, each of the steel coating formed No. Manufacturing conditions No. In combination, a steel sectional processed FIB (Focused Ion Beam), observing the range of 10 [mu] m × 10 [mu] m at a transmission electron microscope (TEM), coating SiO 2 was confirmed to consist of.
　Furthermore, analysis of the surface with Fourier transform infrared spectroscopy (FT-IR), the wave number 1250 (cm -1 peak is present at the position of). This peak, SiO 2 since the peak derived, from this, the film is SiO 2 was confirmed to fit to be formed with.
　Further, with respect to steel sheet with a coating, when subjected to X-ray diffraction, only a halo was detected except the peak of the base steel, a particular peak is not detected.
　That is, both formed film was an amorphous oxide coating.
[0079]
　Next, to evaluate the adhesion of the tension insulating film, the amorphous oxide film formed was oriented electrical steel sheet, aluminum phosphate, the tension insulating film-forming coating liquid consisting of chromic acid and colloidal silica coating and, 30 seconds at 850 ° C., by baking, to produce a tension insulating film having a directional magnetic steel sheet.
[0080]
　It was taken from the tension insulating film having a directional electromagnetic steel sheet produced samples, wrapped into a cylindrical diameter 20 mm (bent 180 °), with a coating residual area ratio after bending back and rated the coating adhesion of the insulating coating. Evaluation of coating adhesion of the insulating coating was determine the presence or absence of peeling of the tension insulating film visually. Not peeled off from the steel plate, the coating remaining area ratio was of 90% or more GOOD, where coating remaining area ratio is less than than 80% 90% OK, the coating remaining area ratio of less than 80% NG.
[0081]
　To measure the glossiness of the surface of the amorphous oxide film with one oriented electrical steel sheets to form a tension insulating coating, the product steel sheets to form a tension insulating film tension insulating film, 80 20% sodium hydroxide ℃ It is selectively removed by a wet etching immersing in an etching solution for 20 minutes.
[0082]
　The gloss of the surface of the selectively removed oriented electrical steel sheet tension insulating coating, using BYK-Gardner Co. micro tri gloss gloss meter (4446), standard methods JIS Z-8741 (incident angle 60 black glass reference board in ° the value measured (refractive index 1.567) 100 was measured by the method) defining a gloss.
[0083]
　Table 2 shows the evaluation of the coating adhesion to the gloss and the tension insulating film.
[0084]
[Table 2]

[0085]
　From Table 2, gloss of the surface of the amorphous oxide film having a directional electromagnetic steel sheet is 150% or more, it can be seen that satisfactory coating adhesion is obtained.
Industrial Applicability
[0086]
　As described above, according to the present invention, it is possible to provide an amorphous oxide film having a directional electromagnetic steel sheet having excellent adhesion tension insulating film and the steel sheet forming the surface of the steel sheet. Accordingly, the present invention has high applicability in the electromagnetic steel sheet manufacturing industry and the electromagnetic steel sheets utilize industry.

The scope of the claims

[Requested item 1]
Steel plate and,
　　, and an amorphous oxide film formed on the steel sheet
　has a
　surface glossiness is 150% or more
　oriented electrical steel sheet, characterized in that.
[Requested item 2]
[Correction 10.09.2019 under Rule 91]　
　　The steel sheet, as a chemical composition, in
　mass%, C: 0.085% or
　less, Si: 0.80
　~ 7.00%, Mn: 1.00% or
　less, Al : 0.065% or
　less, S: 0.013% or
　less,
　Cu: 0 ~
　0.80%, N: 0 ~ 0.012%, P:
　0 ~ 0.5%, Ni: 0 ~ 1.0% ,
　Sn:
　0 ~ 0.3%, Sb: 0 ~ 0.3%,
contains, with the balance being Fe and impurities
oriented electrical steel sheet according to claim 1, characterized in that.
[Requested item 3]
　Said steel sheet, as the chemical composition, by mass%, Cu: oriented electrical steel sheet according to claim 2, characterized in that it contains 0.01 to 0.80%.
[Requested item 4]
　The gloss, oriented electrical steel sheet according to any one of claims 1 to 3, characterized in that a glossiness measured by the method described in JIS Z-8741.