The present invention, grain-oriented electrical steel sheet used as an iron core material of a transformer, in particular, relates to good oriented electrical steel sheet adhesion tension insulating coating.
　This application, on July 13, 2017, claiming priority on Japanese Patent Application No. 2017-137417 filed in Japan, the contents of which are incorporated herein.
BACKGROUND
[0002]
　Oriented electrical steel sheet is mainly used in the transformer. Transformer is continuously energized for a long time before it is discarded from the seated, since the energy losses continue to occur, the energy loss when magnetized by alternating current, i.e., iron loss, transformers the key indicators to determine the value.
[0003]
　In order to reduce the iron loss of grain-oriented electrical steel sheet, until now, many developers have been made. For example, the crystal structure, to increase the accumulation of the {110} <001> orientation called Goss orientation in a steel sheet, increasing the content of solid solution elements such as Si to increase the electrical resistance, decreasing the thickness of the steel sheet it is, and the like.
[0004]
　Further, to impart tension to the steel sheet, it is known to be effective in reducing the iron loss. In order to impart tension to the steel sheet, the smaller the material of the coating coefficient of thermal expansion than the steel, it is effective to form at high temperatures. In the finish annealing step, forsterite film oxide with annealing separator, the steel sheet surface is produced by the reaction can tension the steel sheet has excellent coating adhesion.
[0005]
　A method of forming a patent disclosed in the literature 1, colloidal silica and phosphate insulation baked coating liquid consisting mainly of coating large effect of tensioning to the steel sheet is effective in reducing iron loss. Therefore, after leaving the forsterite film generated in the finish annealing step, it is subjected to insulating coating mainly comprising phosphate, and has a production method of common grain-oriented electrical steel sheet.
[0006]
　On the other hand, the domain wall motion is inhibited by the forsterite film, it became clear that an adverse effect on iron loss. In the grain-oriented electrical steel sheet, magnetic domains, under the alternating magnetic field varies with the movement of the domain walls. That the domain wall movement is smoothly are effective in iron loss improvement, forsterite coating, since it has an uneven structure in the steel / insulating film interface, smooth movement of the domain wall is hindered, the iron loss Adversely affect.
[0007]
　Therefore, to suppress the formation of forsterite coating, a technique for smoothing the surface of the steel sheet has been developed. 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 after finish annealing, a technique for smoothing the surface of the steel sheet It has been disclosed.
[0008]
　Thus, when the steel sheet surface was smoothed, as a method of forming a tension insulating film having a sufficient adhesion, Patent Document 6, after forming the amorphous oxide film on the surface of the steel sheet, the tension insulating film a method of forming is disclosed. Further, Patent Documents 7 to 11, for the purpose of adhesion to form a high tension insulating film, a technique for controlling the structure of the amorphous oxide film is disclosed.
[0009]
　The method disclosed in Patent Document 7, after performing a process before introducing fine unevenness on the surface of the steel sheet of the smoothed-oriented electrical steel sheet, to form an external oxide type oxide, the thickness of the external oxide film the structure with a particulate external oxide based on silica penetrating form, a method of securing the coating adhesion tension insulating coating.
[0010]
　The method disclosed in Patent Document 8, in the heat treatment process for forming the external oxidation type oxide film on the surface of the steel sheet of the smoothed-oriented electrical steel sheet, 200 ° C. or higher 1150 ° C. or less of the Atsushi Nobori rate of the temperature increase zone 10 ° C. / sec or higher 500 ° C. / sec to control the following 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 tension insulating film it is a way to ensure coating adherence.
[0011]
　The method disclosed in Patent Document 9, the external oxide type oxide film is formed on the surface of the steel sheet of the smoothed-oriented electrical steel sheet, followed by, in the step of forming a tension insulating coating, steel sheet and the tension insulating with external oxidized oxide film the contact time of the film coating liquid was below 20 seconds, the ratio of the density reduction layer in the outer oxidized oxide film by 30% or less, a method of securing the coating adhesion tension insulating coating.
[0012]
　The method disclosed in Patent Document 10, followed by heat treatment to form an external oxide type oxide film on the surface of the steel sheet of the smoothed-oriented electrical steel sheet at temperatures above 1000 ° C., to 200 ° C. from the formation temperature of the external oxide type oxide film controlling the cooling rate of the temperature range below 100 ° C. / sec, a cavity in the external oxide type oxide film by 30% or less in the cross-sectional area ratio, a way to ensure the coating adhesion tension insulating coating is there.
[0013]
　The method disclosed in Patent Document 11, in the heat treatment step of forming an external oxidation type oxide film on the surface of the smoothed-oriented electrical steel sheet, the heat treatment, the heat treatment temperature 600 ° C. or higher 1150 ° C. or less, dew point -20 ° C. or higher 0 ° C. performed under the following conditions, and cooled, carried out in an atmosphere dew point 5 ° C. or higher 60 ° C. the following conditions, thereby containing 5% to 30% or less of the metal iron sectional area ratio in the outer oxide type oxide film in a way to ensure coating adhesion tension insulating coating.
[0014]
　However, in the above prior art, it is difficult to sufficiently secure the film adhesion tension insulating coating.
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 07- 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
Non-patent literature
[0016]
Non-Patent Document 1: B. D. CULITY, Gentaro Matsumura, "Kariti new edition X-ray diffraction main theory, Agne Shofusha (1980)", p. 94
Summary of the Invention
Problems that the Invention is to Solve
[0017]
　In view of the state of the prior art, no forsterite coating at the interface tension insulating film and the steel sheet surface, even in the smoothed-oriented electrical steel sheet surface of the steel sheet, increasing the coating adhesion tension insulating coating It was a problem, and an object thereof is to provide a grain-oriented electrical steel sheet to solve the problem.
Means for Solving the Problems
[0018]
　The present inventors have intensively studied a technique for solving the above problems. As a result, the cristobalite type aluminum phosphate obtained by X-ray diffraction of the tension insulating film (XRD), as an index the half width of a peak at a specific angle (FWHM), it is possible to evaluate the coating adhesion tension insulating coating if Osamere the index within the required range, it has been found that sufficiently ensured coating adhesion tension insulating coating.
[0019]
　The present invention has been made based on the above findings and has as its gist is as follows.
[0020]
　(1) oriented electrical steel sheet according to one embodiment of the present invention includes a base steel sheet, formed on the base material steel plate, SiO amorphous 2 and oxide film composed of, formed on the oxide on the film comprising a tension insulating film that is, a. The base material steel plate, as chemical components, by mass%, C: 0.085% or less, Si: 0.80 ~ 7.00%, Mn: 1.00% or less, acid soluble Al: 0.065% or less , Seq represented by S + 0.406 · Se: 0.050% or less, containing the balance: Fe and impurities. Is a half-value width of the peak of cristobalite type aluminum phosphate obtained by X-ray diffraction FWHM is, (i) when the X-ray diffraction using a Co-K [alpha excitation source, a half of the peak appearing at 2 [Theta] = 24.8 ° FWHM-Co is 2.5degree less a width, or is (ii) when the X-ray diffraction using Cu-K [alpha excitation source, a half width of the peak appearing at 2θ = 21.3 ° FWHM-Cu 2.1degree is less than or equal to.
[0021]
　(2) oriented electrical steel sheet according to the above (1) may not have a forsterite coating.
[0022]
　(3) the base steel sheet, as the chemical components, further contains, by mass%, N: 0.012% or less, P: 0.50% or less, Ni: 1.00% or less, Sn: 0.30% hereinafter, Sb: 0.30% or less, Cu: may include one or more from 0.01 to 0.80%.
The invention's effect
[0023]
　According to the present invention, even without forsterite coating at the interface tension insulating film and the steel sheet surface, the steel sheet surface, it is possible to provide an oriented electrical steel sheet having excellent tension insulating coating film adhesion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024]
Is an example of FIG. 1] X-ray diffraction was carried out using a Co-K [alpha radiation source (XRD).
Is a diagram showing the relationship between FIG. 2] X-ray diffraction (XRD) half-width and the film remaining area ratio of the tension insulating film of the peak.
DESCRIPTION OF THE INVENTION
[0025]
　Oriented electrical steel sheet of the present invention (hereinafter sometimes referred to as "the present invention electrical steel sheet".) Has a base material steel plate, is formed on the base material steel plate, SiO amorphous 2 and oxide film made of, and a tension insulating film formed on said oxide on the film.
　The base material steel plate, as chemical components, by mass%, C: 0.085% or less, Si: 0.80 ~ 7.00%, Mn: 1.00% or less, acid soluble Al: 0.065% or less , Seq represented by S + 0.406 · Se: containing 0.050% or less, the balance being Fe and impurities.
　Is a half-value width of the peak of cristobalite type aluminum phosphate obtained by X-ray diffraction FWHM is, (i) when the X-ray diffraction using a Co-K [alpha excitation source, a half of the peak appearing at 2 [Theta] = 24.8 ° FWHM-Co is 2.5degree less a width, or is (ii) when the X-ray diffraction using Cu-K [alpha excitation source, a half width of the peak appearing at 2θ = 21.3 ° FWHM-Cu 2.1degree is less than or equal to.
[0026]
　Hereinafter, the present invention will be described in detail an electromagnetic steel sheet.
[0027]
　The present inventors have found that there is no forsterite coating, in the directional electromagnetic steel plates, causes the coating adhesion tension insulating film is not necessarily sufficient, generated with the decomposition of the aluminum phosphate contained in the tension insulating film considering the differences in the amount of moisture.
[0028]
　That is, the amount of difference in the moisture generated due to decomposition of the aluminum phosphate, the structure of the amorphous oxide film varies formed at the interface of the tension insulating film and the steel sheet surface, as a result, the tension insulating coating film were considered is not the difference of occurs in the adhesion.
[0029]
　Then, the present inventors have been decomposed sufficiently proceed aluminum phosphate, increases the amount of moisture generated, amorphous oxide film is sufficiently formed, improved coating adhesion tension insulating coating Suruga, while with the degradation of the aluminum phosphate, the crystallization of aluminum phosphate was speculated that it would be to proceed.
[0030]
　Accordingly, the present inventors have investigated the X-ray diffraction results and film adhesion of the relationship in the case of changing the baking conditions in the baking process of the tension insulating film (oxygen partial pressure).
[0031]
　As a test material, the decarburization annealed sheet having a thickness of 0.23 mm, subjected to a finish annealing by applying an annealing separator consisting mainly of alumina, secondary recrystallization is of the directional electromagnetic steel plates no forsterite coating It was prepared.
[0032]
　This grain-oriented electrical steel sheet, aluminum phosphate, chromic acid, and a coating liquid composed mainly of colloidal silica was applied, the oxygen partial pressure (P H2 O / P H2 ): in an atmosphere of 0.008 to 0.500 , a baking treatment at a soaking temperature 870 ° C. and the soaking time of 60 seconds, to produce a grain-oriented electrical steel sheet having a tensile insulating coating.
[0033]
　The surface of the grain oriented electrical steel sheets were subjected to X-ray diffraction using a Co-K [alpha radiation source (XRD).
[0034]
　Figure 1 shows an example of X-ray diffraction was carried out using a Co-K [alpha radiation source (XRD). The present inventors have found that in the X-ray diffraction (XRD) patterns, by paying attention to the peak of cristobalite type aluminum phosphate appearing at 2 [Theta] = 24.8 °, was determined half-width (FWHM) of the peak. Other major peaks in the X-ray diffraction (XRD) patterns of the aluminum phosphate is a Toridemaito type peak appearing at 2θ = 34.3 °. If subjected to X-ray diffraction under the conditions of the slit width 1.0 mm (XRD) using Cu-K [alpha radiation source, the 2 [Theta] = 21.3 °, a peak of cristobalite type aluminum phosphate appears.
[0035]
　Then, the present inventors have found that in the grain-oriented electrical steel sheet thus produced, by X-ray diffraction (XRD), the half width of the peak of cristobalite type aluminum phosphate appearing at 2θ = 24.8 ° (FWHM) and tension insulating film the film adhesion of the relationship was investigated.
[0036]
　Coating adhesion, when wrapped 180 ° the specimen cylinder having a diameter of 20 mm, the film does not peel from the steel plate, (sometimes hereinafter referred to as "film remaining area ratio".) Area ratio of the portion that remains in close contact with evaluated.
[0037]
　Figure 2 shows the relationship between the X-ray diffraction (XRD) coating remaining area ratio of the half width and the tension insulating film of the peak. From Figure 2, the cristobalite type aluminum phosphate oriented electrical steel sheet, the half width of the peak appearing at 2θ = 24.8 ° (FWHM) is 2.5 or less, the film residual area ratio becomes 80% or more, further, when the half-width (FWHM) is 1.0 or less, the film residual area ratio is seen to be a more than 90%.
[0038]
　Therefore, in the present invention electrical steel sheet, when the Co-K [alpha excitation source, 2 [Theta] = 24.8 ° appearing half width (FWHM-Co) was defined to be less than 2.5Degree (requirement (i)). This point is a feature of the present invention electrical steel sheet.
[0039]
　Further, the present inventors have found that when subjected to X-ray diffraction under the conditions of the slit width 1.0 mm (XRD) using Cu-K [alpha radiation source, cristobalite type aluminum phosphate appearing at 2 [Theta] = 21.3 ° When the half width of the peak (FWHM-Cu) is a 2.1 (degree) hereinafter, the coating remaining area ratio of the tension insulating film is 80% or more, was confirmed in a similar study.
　In the X-ray diffraction, using an X-ray diffractometer SmartLab manufactured by Rigaku Corporation. The measurement method was used oblique incidence X-ray diffraction method.
[0040]
　Therefore, in the present invention electrical steel sheet, when the Cu-K [alpha excitation source, 2 [Theta] = 21.3 ° appearing half width (FWHM-Cu) is defined to be less than 2.1Degree (requirement (ii)). This point is also a feature of the present invention electrical steel sheet.
[0041]
　The above features of the present invention electrical steel sheet, since it is based on X-ray diffraction characteristics of the tension insulating film, in the present invention electrical steel sheet, with or without a forsterite coating interfacial tension insulating film and the steel sheet surface, with this characteristic, it is possible to sufficiently secure the film adhesion tension insulating coating.
[0042]
　Furthermore, the present inventors have described in Non-Patent Document 1, focusing on the equation of Scherrer formula (1).
　Crystallite size (Å) = K × λ / (β × cosθ) ··· (1)
[0043]
　In the formula of Scherrer for defining the crystallite size, K is Scherrer constant (0.9), lambda is a wavelength of X-ray (Å), β is the half-value width of the XRD peaks of the diffraction angle 2 [Theta], theta is the diffraction angle. In the case of X-ray diffraction that the Co-K [alpha radiation source (XRD), lambda is 1.7889.
[0044]
　Half-width of the film adhesion good specimens, the coating adhesion is small compared to the half-width of the defective specimens. This crystallite size of the film adhesion good specimens, as estimated from the equation Scherrer, larger than the crystallite size of the film adhesion poor specimen, i.e., the tension insulating film suggesting that crystallization is in progress.
[0045]
　[Base steel sheet]
　Next, a description will be given composition of the base material steel plate. Hereinafter,% means mass%.
[0046]
　C: 0.085% or less
　C is an element significantly increase the core loss by magnetic aging. When C exceeds 0.085%, the iron loss increases considerably, C is not more than 0.085%. Preferably 0.010% or less, more preferably 0.005% or less. C, since preferred for the reduction of a small amount as the iron loss, but the lower limit is not particularly limited, since the order of 0.0001% is a detection limit of 0.0001% are substantially the lower.
[0047]
　Si: 0.80 ~
　7.00% Si controls the secondary recrystallization in secondary recrystallization annealing, an element which contributes to the improvement of the magnetic properties. When Si is less than 0.80%, the steel sheet is transformed phase in the secondary recrystallization annealing, it is difficult to control the secondary recrystallization, so no good magnetic flux density and iron loss characteristics can be obtained, Si is 0.80% or more. Preferably 2.50% or more, and more preferably not less than 3.00%.
[0048]
　On the other hand, when the Si is more than 7.00%, the steel sheet is embrittled, so sheet passing property in the manufacturing process is significantly deteriorated, Si is not more than 7.00%. Preferably 4.00% or less, and more preferably not more than 3.75%.
[0049]
　Mn: 1.00% or less
　Mn is an austenite forming element, to control the secondary recrystallization in secondary recrystallization annealing, an element which contributes to the improvement of the magnetic properties. When Mn is less than 0.01%, there is a case where the steel sheet during hot rolling becomes brittle, Mn is preferably at least 0.01%. More preferably 0.05% or more, further preferably 0.10% or more.
[0050]
　On the other hand, when the Mn exceeds 1.00%, the steel sheet is transformed phase in the secondary recrystallization annealing, so no good magnetic flux density and iron loss characteristics were obtained, Mn is not more than 1.00%. Preferably 0.70% or less, more preferably 0.50%.
[0051]
　Acid-soluble Al: 0.065% or less
　acid-soluble Al combines with N, is an element that generates functions as an inhibitor (Al, Si) N. When the acid-soluble Al is less than 0.010%, the less the amount of AlN, because secondary recrystallization may not proceed sufficiently, it is preferable acid-soluble Al is 0.010% or more. More preferably 0.015% or more, further preferably 0.020% or more.
[0052]
　On the other hand, if the acid soluble Al is more than 0.065%, AlN precipitation becomes uneven, can not be obtained the required secondary recrystallized structure, magnetic flux density decreases, and since the steel sheet becomes brittle, acid-soluble Al is a 0.065% or less. Preferably 0.060% or less, more preferably 0.050% or less.
[0053]
　Seq (= S + 0.406 · Se ): 0.050% or less
　S and / or Se is combined with Mn, is an element which forms the MnS and / or MnSe functioning as inhibitors. Amount, taking into account the atomic weight ratio of S and Se, defined by Seq = S + 0.406 · Se.
[0054]
　When Seq is less than 0.003%, because the addition effect may not sufficiently expressed, Seq is preferably 0.003% or more. More preferably 0.005% or more, further preferably 0.007% or more.
[0055]
　On the other hand, when the Seq exceeds 0.050% precipitation dispersion of MnS and / or MnSe becomes uneven, the required secondary recrystallized structure can not be obtained, since the magnetic flux density decreases, Seq 0.050 % or less to be. Preferably 0.035% or less, more preferably 0.015% or less.
[0056]
　In the base steel sheet, the balance excluding the element is Fe and impurities (inevitable impurities). Impurities (inevitable impurities) is an element which inevitably mixed in steel raw material and / or steel manufacturing process.
[0057]
　The base steel sheet is within a range not to impair the characteristics of the present invention electrical steel sheet, N: 0.012% or less, P: 0.50% or less, Ni: 1.00% or less, Sn: 0.30% or less, Sb : 0.30% or less, Cu: it may contain one or more 0.01 to 0.80%.
[0058]
　N: 0.012% or less
　N combines with Al, is an element to form AlN that functions as an inhibitor, the cold rolling is also an element forming a blister (holes) in the steel sheet. If N is less than 0.001%, the formation of AlN becomes insufficient, N is preferably 0.001% or more. More preferably 0.006% or more.
[0059]
　On the other hand, when N exceeds 0.012% cold rolling, there is a concern that the blister (vacancies) are generated in the steel sheet, N is preferably 0.012% or less. More preferably not more than 0.010%.
[0060]
　P: 0.50% or less
　P is raising the specific resistivity of the steel sheet, an element which contributes to the reduction of iron loss. If P exceeds 0.50%, since the rolling resistance decreases, P is preferably 0.50% or less. More preferably not more than 0.35%. The lower limit includes 0%, in order to increase the addition effect reliably, preferably at least 0.02%.
[0061]
　Ni: 1.00% or less
　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 Ni exceeds 1.00%, since the secondary recrystallization proceeds unstable, Ni is preferably 1.00% or less. More preferably not more than 0.75%. The lower limit includes 0%, in order to increase the addition effect reliably, preferably at least 0.02%.
[0062]
　Sn: 0.30% or less
　Sb: 0.30% or less
　Sn and Sb is segregated in the grain boundary, the finish annealing, the annealing separator agent Al is oxidized by moisture release (in this oxidation, the coil position in different inhibitor strength, it is an element which forms the function of preventing the magnetic characteristics fluctuate) to.
[0063]
　If any of the elements also exceeds 0.30%, the secondary recrystallization becomes unstable, because the magnetic characteristics are degraded, none of Sn and Sb preferably 0.30% or less. More preferably, each element also below 0.25%. The lower limit includes 0%, in order to increase the addition effect reliably, each element is also preferably not less than 0.02%.
[0064]
　Cu: 0.01 ~
　0.80% Cu combines with S and / or Se, is an element which forms a precipitate that acts as an inhibitor. If Cu is less than 0.01%, the addition effect is not exhibited sufficiently, Cu is preferably 0.01% or more. More preferably 0.04% or more.
[0065]
　On the other hand, when the Cu exceeds 0.80% dispersion of precipitates becomes inhomogeneous, since the iron loss reducing effect is saturated, Cu is preferably 0.80% or less. More preferably 0.60%.
[0066]
　[Oxide coating]
　oriented electrical steel sheet according to the present embodiment is formed on a base steel sheet, SiO amorphous 2 comprises an oxide film consisting of.
　Oxide coating has a function of adhering the base steel sheet and the tension insulating film.
[0067]
　The oxide coating on the base steel sheet is formed, can be confirmed by a steel cross-section is processed FIB (Focused Ion Beam), observing the range of 10 [mu] m × 10 [mu] m with a transmission electron microscope (TEM) it can.
[0068]
　[Tension insulating coating]
　tension insulating film is formed on the oxide coating, phosphate and colloidal silica (SiO 2 is a vitreous insulating coating formed by baking by applying a solution mainly composed of).
　This tension insulating film, it is possible to impart a high surface tension in the base steel sheet.
[0069]
　Next, a method for manufacturing of the present invention electrical steel sheet.
[0070]
　The molten steel required chemical composition, by casting in a conventional manner to a slab (material). The slab was subjected to ordinary hot rolling, the hot rolled steel sheet. Then, subjected to a hot-rolled sheet annealing in the hot-rolled steel sheet. Then, one cold rolling, or is subjected to a plurality of cold rolling sandwiching the intermediate annealing, to produce a steel sheet having a final sheet thickness. Then, subjected to a decarburization annealing the steel plate.
[0071]
　In the decarburization annealing, the heat treatment in wet hydrogen, the C content of the steel sheet, reducing the product plate to the content is no deterioration of the magnetic characteristics due to magnetic aging. Furthermore, the decarburization annealing, the steel sheet structure is primary recrystallization, to prepare the secondary recrystallization. Further, by annealing the steel sheet in an ammonia atmosphere, to produce an AlN inhibitor. Subsequently, a finish annealing at 1100 ℃ or higher.
[0072]
　Finish annealing is a steel sheet surface, the purpose of anti-seizing of the steel plate, Al 2 O 3 was coated with an annealing separator mainly comprised of, performed in the form of a wound coil of steel sheet. After finish annealing, it is removed by washing the excess annealing separator, (post-treatment step). Then formed annealing, the amorphous oxide film in a mixed atmosphere of hydrogen and nitrogen.
[0073]
　In the post-treatment process after finish annealing, washing to remove excess annealing separator, with a scrubber brush. The post-treatment step after annealing the finish according to the present embodiment, the rotational speed of the scrubber brush and 500 ~ 1500 rpm. Thus, the area of ​​the metal active surface is increased, the amount of elution of Fe ions is increased during the subsequent thermal oxidation annealing and coating baking. As a result, iron phosphate formed is accelerated, crystalline aluminum phosphate is changed. Rotational speed of the scrubber brushes, more preferably 800 ~ 1400 rpm, more preferably from 1000 ~ 1300 rpm.
[0074]
　The partial pressure of oxygen in the mixed atmosphere of forming an amorphous oxide film is preferably 0.005 or less, more preferably 0.001 or less. Further, the holding temperature is preferably 600 ~ 1150 ° C., more preferably 700 ~ 900 ° C..
[0075]
　In order to control the crystal size of the cristobalite type aluminum phosphate, conditions in the baking step after coating the tension insulating film coating liquid on the surface of the steel sheet is also important. That is, in order to advance the crystallization of aluminum phosphate, in addition to the rotational speed of the scrubber brush in post-treatment step after finish annealing, it is important to set a low oxygen partial pressure in the baking step.
[0076]
　The oxygen partial pressure in the baking step is preferably 0.008 or more than 0.200. When the oxygen partial pressure is lower than 0.008, degradation of the aluminum phosphate becomes excessive, or coating defects occur, since reacts with iron coating is blackened, the oxygen partial pressure is preferably 0.008 or more . More preferably 0.015 or more.
[0077]
　On the other hand, if the oxygen partial pressure exceeds 0.200, the crystallization of aluminum phosphate does not proceed, the oxygen partial pressure is preferably 0.200 or less. More preferably 0.100 or less.
[0078]
　The baking step, the holding temperature of 800 ~ 900 ° C., it is preferable to bake under the condition of 30 to 100 seconds baking time.
　When the holding temperature is less than 800 ° C., the crystal of the aluminum phosphate does not proceed sufficiently, the holding temperature is preferably at least 800 ° C.. More preferably 835 ° C. or higher. On the other hand, when the holding temperature exceeds 900 ° C., decomposition of aluminum phosphate becomes excessive, or coating defects occur, since reacts with iron coating is blackened, the holding temperature is preferably 900 ° C. or less. More preferably 870 ° C. or less.
　When baking time is less than 30 seconds is not preferable because the crystallization of aluminum phosphate does not sufficiently proceed. When baking time is 100 seconds, greater than the degradation of aluminum phosphate becomes excessive, or coating defects occur, since reacts with iron coating is blackened, is not preferable.
[0079]
　Thus, after applying the tension insulating film coating liquid, it is possible to coat adhesion obtain good grain-oriented electrical steel sheet.
Example
[0080]
　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, it is capable of adopting various conditions.
[0081]
　(Example)
　Table subjected 1-1 shows the component composition slabs (silicon steel) to the heated hot rolling to 1100 ° C., and hot-rolled steel sheet having a thickness of 2.6 mm, at 1100 ° C. to the heat-rolled steel sheet after annealed, and a plurality of times of cold subjected to rolling final thickness cold rolled steel sheet 0.23mm sandwiching the rolling or intermediate annealing between single cold.
[0082]
[Table 1-1]

[0083]
　Was subjected to decarburization annealing and nitriding annealing the cold-rolled steel sheet was coated with a water slurry of the annealing separator consisting mainly of alumina on the surface of the steel sheet. Next, 1200 ℃, was finished annealing of 20 hours. After finish annealing, followed by washing with water removes the excess annealing separator, with a scrubber brush. The rotational speed of the scrubber brush shown in Table 2.
　This eliminates the forsterite film to obtain a grain-oriented electrical steel sheet secondary recrystallization is completed with a specular gloss. The chemical composition of the base material steel plate are shown in Table 1-2.
[0084]
[Table 1-2]

[0085]
　This grain-oriented electrical steel sheet, nitrogen: 25% hydrogen, 75 percent, and an oxygen partial pressure in 0.0005 atmosphere, was subjected to soaking treatment for 30 seconds at 800 ° C.. Thereafter, nitrogen: 25% hydrogen, 75 percent, and an oxygen partial pressure in 0.0005 atmosphere, the heat treatment is cooled to room temperature to form an amorphous oxide film on the surface of the steel sheet.
[0086]
　This amorphous oxide film having a directional magnetic steel sheet, a tension insulating film coating liquid consisting of aluminum phosphate and colloidal silica was applied, nitrogen: 25% hydrogen, 75 percent, and oxygen as shown in Table 2 in the partial pressure atmosphere, subjected to a baking treatment under the conditions of baking temperature and baking temperature shown in Table 2, to obtain a grain-oriented electrical steel sheet. The film adhesion of the resulting grain-oriented electrical steel sheet was thus evaluated. The results are shown in Table 3.
[0087]
　Incidentally, to form the invention Examples B8 ~ B10 in forsterite coating. Forming method is as follows.
　The cold-rolled steel sheet, was subjected to decarburization annealing and nitriding annealing was coated an aqueous slurry of an annealing separator composed mainly of MgO to the steel sheet surface. Next, 1200 ℃, was finished annealing of 20 hours.
[0088]
[Table 2]

[0089]
[table 3]

[0090]
　To evaluate the crystallinity, incidence angle: 0.5 ° certain conditions, and, in the conditions of the slit width 1.0 mm, was subjected to oblique incidence X-ray diffraction using a Co-K [alpha radiation source. After performing the X-ray diffraction to determine the half-width of cristobalite type aluminum phosphate appearing at 2θ = 24.8 °.
[0091]
　In order to evaluate the crystallinity, incidence angle: 0.5 ° certain conditions, and, in the conditions of the slit width 1.0 mm, it was subjected to oblique incidence X-ray diffraction using Cu-K [alpha radiation source. After performing the X-ray diffraction to determine the half-width of cristobalite type aluminum phosphate appearing at 2θ = 21.3 °.
　In the X-ray diffraction, using an X-ray diffractometer SmartLab manufactured by Rigaku Corporation. The measurement method was used oblique incidence X-ray diffraction method.
[0092]
　Next, wrapped specimen cylinder having a diameter of 20 mm, were evaluated coating adhesion tension insulating film with a coating remaining area ratio when bent 180 °. Coating adhesion tension insulating coating is not peeled off from the steel plate, Good coatings remaining area of ​​90% or more, Fair the coating remaining area ratio 80% or more and less than 90%, the coating remaining area ratio is less than 80% Poor It was evaluated as. The evaluation results were as acceptable of Good or Fair.
[0093]
　From Table 3, in the invention examples, the coating adhesion evaluation results are passed both, it can be seen that the coating adhesion tension insulating film is excellent. On the other hand, in the comparative example, film adhesion property evaluation results are all that failed.
[0094]
　Incidentally, when the Examples and Comparative Examples of the cross-section of Table 3 FIB (Focused Ion Beam) is processed, to confirm the formation of the oxide film by observing the range of 10 [mu] m × 10 [mu] m at a transmission electron microscope (TEM), oxide coating has been formed in all of the examples and comparative examples.
Industrial Applicability
[0095]
　As described above, according to the present invention, even without forsterite coating at the interface tension insulating film and the steel sheet surface, the steel sheet surface, providing a grain-oriented electrical steel sheet having excellent tension insulating coating film adhesion can do. Accordingly, the present invention has high applicability in the electromagnetic steel sheet production and use industries.

WE claims

[Requested item 1]
　; Base material steel plate and
　is formed on the base steel sheet on, SiO amorphous 2 and oxide film consisting of:
　and the oxide film on the formed tension insulating film;
equipped with,
　the base material steel plate, as chemical components, by
　　mass%, C: 0.085% or
　　less; Si: 0.80
　　~ 7.00%; Mn: 1.00% or less;
　　acid-soluble Al: 0.065% or
　　less; S + 0.406 · Se in represented by Seq: 0.050% or less;
containing,
　balance: Fe and impurities,
　is a half-value width of the peak of cristobalite type aluminum phosphate obtained by X-ray diffraction FWHM
　　is, (i) Co- when the X-ray diffraction using the K [alpha excitation source, a half width of the peak appearing at 2θ = 24.8 ° FWHM-Co is less than 2.5Degree;
or,
　　with (ii) Cu-Kα excitation source when the X-ray diffraction Te, 2 [Theta] = 2 .3 FWHM-Cu is a half width of the peak appearing in ° is less than 2.1Degree;
oriented electrical steel sheet, characterized in that.
[Requested item 2]
　Oriented electrical steel sheet according to claim 1, characterized in that no forsterite coating.
[Requested item 3]
　Characterized in that said base material steel plate, as the chemical components, further contains, by
　mass%, N: 0.012% or
　less; P: 0.50% or
　less; Ni: 1.00% or
　less; Sn: 0.30% or
　less; Sb : 0.30% or
　less; Cu: 0.01 ~ 0.80%
oriented electrical steel sheet according to claim 1 or 2, characterized in that it comprises one or more.