[0001]The present invention relates to a grain-oriented electrical steel sheet.
BACKGROUND
[0002]
　Conventionally, as a steel sheet for transformer iron core (core) is oriented electrical steel sheet exhibiting excellent magnetic properties in a particular direction are known. The oriented electrical steel sheet, by a combination of annealing and cold rolling, a steel sheet crystal orientation is controlled so that the crystal grains of the easy magnetization axis and the rolling direction coincides. It is desirable iron loss oriented electrical steel sheet is as low as possible.
[0003]
　To reduce iron loss, grain-oriented electrical steel sheet insulating film formed on the surface of the crystal orientation as described above is controlled steel (base steel) is known. The insulating coating is not only electrically insulating, tension and heat resistance, also serves to provide further rust resistance and the like of the steel sheet.
[0004]
　As a method for reducing iron loss In addition, a groove extending in a direction crossing the rolling direction on the surface of the steel sheet, by forming at a predetermined distance along the rolling direction, a readily magnetic wall movement subdividing magnetic domains magnetic domain control method of reducing the iron loss has been known to.
[0005]
　As a method of forming a groove on the steel sheet surface, a method of performing chemical etching (Patent Document 1) and the laser irradiation method (Patent Documents 2-5) method and the like are known.
[0006]
　When forming a groove in the chemical etching, while the costs associated equipment installation is enormous, according to the laser irradiation method, relatively, it is possible to form the groove easily and stably steel sheet surface. A method of forming a groove by performing a laser irradiation after the formation of the insulating film is described in Patent Documents 3-5.
[0007]
　However, in this method, it is impossible to avoid loss of the insulating film due to the formation of the groove. When the insulating film is lost, rust is likely to occur. Although it is possible to improve the rust resistance by forming an insulating film after formation of the groove, the cost is increased.
CITATION
Patent Document
[0008]
Patent Document 1: JP-A-6-100939 JP
Patent Document 2: JP-A 6-57335 Patent Publication
Patent Document 3: Japanese Patent No. 5234222 discloses
Patent Document 4: JP 2012-177164 Patent Publication
Patent Document 5: JP 2012- 87,332 JP
Summary of the Invention
Problems that the Invention is to Solve
[0009]
　To avoid loss of insulating film due to the formation of the groove, it is conceivable to form the grooves before forming the insulating film. However, in this method, molten iron dissolved scattered laser irradiation portion adheres to the surface of the steel sheet around the groove. When the molten iron is attached to the flat surface of the steel sheet, the projections occur there. When forming an insulating film on the projections are formed steel plate, various problems occur in the insulating film. For example, if the projection is large, projection or exposed from the insulating film, cracking or delamination thin part of the insulating film of the peripheral projections may or cause (Patent Document 2). Moreover, such a projection may prevent intimate contact between the oriented electrical steel sheet adjacent in the stack iron core, leading to deterioration and degradation of the building factor space factor increases noise.
[0010]
　The present invention, while avoiding an increase in cost, it is possible to improve the insulation and rust resistance, the direction in which the groove for the domain refining capable of reducing the noise of the laminated iron core is formed on the surface and to provide sexual electromagnetic steel sheet.
Means for Solving the Problems
[0011]
　The gist of the present invention is as follows.
[0012]
　(1)
　the extending direction intersects the rolling direction, comprising a steel sheet and the depth direction has a thickness direction and parallel grooves are formed steel sheet surface,
　and the grooves on both sides of the groove in the surface of the steel sheet there is molten coagulation leading to parallel,
　a virtual plane height as the maximum frequency in the height distribution of the height data of the measurement of the steel sheet surface within a particular area at regular intervals, including the grooves, the virtual plane the void volume of more concave recess and V1, the volume of the convex portion protruding than the virtual plane when the V2, the value of V2 / V1 is less than 0.10 ultra 0.80,
　in the specific region a plurality of projections are formed, among the plurality of protrusions, the width of the closest projection in the groove is greater than the width of the other protrusions,
　the average height of the extending direction in the height distribution is most If viewed in the groove longitudinal cross section including an extending direction and the thickness direction of the high region , The
　average roughness Ra of the roughness curve that forms the surface of the area is a 0.30 ~ 2.00 .mu.m,
　the average length RSm of a roughness curve element which forms the surface of the area is located at 10 ~ 150 [mu] m oriented electrical steel sheet, characterized in that.
[0013]
　(2)
　Height 0.02% th become high in data of said is oriented electrical steel sheet according to, characterized in that 1 an ultra ~ 10 [mu] m (1).
[0014]
　(3)
　the groove peripheral surface of the steel sheet shape, when viewed in Mizonobe lengthwise direction perpendicular groove widthwise cross section,
　of the convex portion, the end portion T of the closest projections on the groove 1s end of said groove the distance L between the parts m s is oriented electrical steel sheet according to characterized in that it is a 0 super ~ 40 [mu] m (1) or (2).
[0015]
　(4)
　among the plurality of protrusions, the width W of the closest projections on the groove 1 is oriented electrical steel sheet according to any one of, wherein the at 40μm or less (1) to (3).
[0016]
　(5)
　among the plurality of protrusions, W the width of the closest projections on the groove 1 , the n-th (n is an integer of 2 or more) the width of the protrusion closer to W n when expressed as, W n / W 1 oriented electrical steel sheet according to any one of the values of and less than 0.20 ultra 1.00 (1) to (4).
[0017]
　(6)
　any of the Mizonobe, wherein the number of crystal grains present in the bottom of the highest elevation in the cross section perpendicular to the lengthwise direction is less than 10.0 in the average (1) to (5) 1 oriented electrical steel sheet according to item.
[0018]
　(7)
　wherein the height crystal orientation of the metal structure of protrusions of the highest region average height of the extending direction in the distribution, characterized in that a {100} <001> orientation area ratio of 65% or more oriented electrical steel sheet according to any one of to (1) to (6).
[0019]
　(8)
　on the steel sheet surface including the surface of the protrusion and the groove surface, oriented electrical steel sheet according to any one of characterized in that it comprises a glass coating film (1) to (7).
Effect of the invention
[0020]
　According to the present invention, since the appropriate projections are formed on the surface of the steel sheet, in grooves oriented electrical steel sheet which is formed on the surface, while avoiding an increase in cost, to improve the insulation and rust resistance can.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021]
[Figure 1A] Figure 1A is a schematic plan view showing the grain-oriented electrical steel sheet according to the embodiment of the present invention.
FIG 1B] Figure 1B is a cross-sectional schematic view showing the grain-oriented electrical steel sheet according to the embodiment of the present invention.
[Figure 2A] Figure 2A is a height distribution diagram of the groove around the grain-oriented electrical steel sheet of the inventive example.
[Figure 2B] Figure 2B is a diagram showing the FIG. 2A 3-dimensionally.
[Figure 3A] Figure 3A is a height distribution diagram of the groove around the grain-oriented electrical steel sheet of the comparative example.
[Figure 3B] Figure 3B is a diagram showing the FIG. 3A 3-dimensionally.
[Figure 4A] Figure 4A, the groove oriented electrical steel sheet of an embodiment of the present invention, is a cross-sectional schematic view viewed in cross section perpendicular to Mizonobe extension direction Y.
[Figure 4B] Figure 4B is a partial enlarged view of Figure 4A.
FIG. 5 is a groove oriented electrical steel sheet of the comparative example, a cross-sectional schematic view viewed in cross section perpendicular to Mizonobe extension direction Y.
FIG. 6 is a projection of the grain-oriented electrical steel sheet of an embodiment of the present invention, a cross-sectional schematic view taken in cross-section including the Mizonobe extension direction Y and the thickness direction Z.
[Figure 7A] Figure 7A is a diagram showing a portion for measuring the number of grains.
[Figure 7B] Figure 7B is a diagram showing a line for measuring the number of grains.
[8] FIG. 8 is a process diagram illustrating the manufacturing method of the grain-oriented electrical steel sheet of an embodiment of the present invention.
FIG 9A] FIG 9A is a schematic diagram showing the occurrence of a molten iron by laser irradiation.
[FIG. 9B] FIG 9B is a schematic diagram showing the formation of a protrusion in accordance with solidification of the molten iron.
FIG 9C] FIG 9C is a schematic diagram showing the occurrence of a molten iron by laser irradiation when a specific material is coated.
FIG 9D] FIG 9D is a schematic diagram showing the formation of a protrusion in accordance with solidification of the molten iron in the case where the specific substance is applied.
FIG 10A] FIG 10A is a diagram illustrating the dimensions of the wound core.
[FIG. 10B] FIG 10B is a diagram illustrating the dimensions of the wound core.
[11] Figure 11 Test No. It is a cross-sectional view schematically showing a steel sheet 1-23.
DESCRIPTION OF THE INVENTION
[0022]
　It will be described in detail embodiments of the present invention. 1A is a plan view showing the grain-oriented electrical steel sheet according to the embodiment of the present invention, FIG. 1B is a cross-sectional view showing a grain-oriented electrical steel sheet according to the embodiment of the present invention.
[0023]
　As shown in FIGS. 1A and 1B, oriented magnetic steel sheet 10 according to the embodiment of the present invention, the steel plate 1 which groove 5 is provided on its surface, a film 2 formed on the surface of the steel sheet of the steel plate 1 It is equipped with a. Film 2 is, for example, the insulating film may include the glass coating film. In Figure 1, the rolling direction X direction of the steel sheet 1, the extending direction of the Y-direction of the groove 5, the plate thickness direction in the Z direction of the steel plate 1, a direction orthogonal to the Y and Z directions is defined as Q direction. However, not the extending direction Y of the groove 5 is limited to the direction shown, it may be a direction intersecting the rolling direction X.
[0024]
　As shown in FIG. 1A, the surface of the steel sheet 1, for domain refining, the extending direction Y crosses the rolling direction X, and the groove depth direction thickness direction Z and a plurality of parallel grooves 5 There are formed at predetermined intervals along the rolling direction X. Molten coagulation 8 is present leading to parallel to the groove 5 on both sides of the groove 5 of the surface of the steel sheet 1. Grooves 5, when viewed from a thickness direction Z, that is, when the groove 5 in a plan view, in, need not be a linear shape, may have a curved portion, it has an arcuate shape it may be. However, in the present embodiment, for convenience of descriptions, it illustrates the groove 5 having a linear shape.
[0025]
　2A and 2B, represents the height distribution of the peripheral region of the grooves of the steel sheet contained in the grain-oriented electrical steel sheet that are within the scope of the present invention, in FIGS. 3A and 3B, outside oriented electrical of the present invention showing the height distribution of the peripheral region of the grooves of the steel sheet contained in the steel sheet. FIG 2A and 3A, to the peripheral region of the grooves extending along the vertical direction of the figure indicates the height distribution measured the height in the Z direction using a laser type surface roughness measuring instrument. FIG 2B and 3B, showing those displayed three-dimensionally. 2A and 2B test described below No. Is an invention example corresponding to 1-1, FIGS. 3A and 3B test described below No. It is a comparative example corresponding to 1-16. In the steel sheet shown in FIGS. 2A and 2B, the convex portion of the steel sheet surface is formed along the groove in the peripheral groove. In contrast, in the steel plate shown in FIGS. 3A and 3B, the convex portion is irregularly formed to a relatively distant area from the groove. Control of such protrusions, described further below.
[0026]
　4A and 4B, the grain-oriented electrical steel sheet of the present embodiment, the one groove 5, a diagram as viewed in cross section (groove widthwise cross section) orthogonal to Mizonobe extension direction Y. 4B is a partial enlarged view of Figure 4A. A plurality of protrusions 7 are formed on the outer surface of the steel sheet in the groove width direction. Protrusions 7 is a region higher than the virtual plane 2a of the height in the Z direction will be described later. Not only roughness controlled Intended, region is higher than the virtual plane 2a due unintentional flaws or small surface variations and measurement errors are included in the convex portion 7. Among the convex portions 7, the height relative to the virtual plane 2a exceeds h / 10, and the width is defined as the projection T of more than h. It will be described later h. In Figure 4A, the three protrusions 7 illustrated in the right side of the groove 5 corresponds to all the projections T. Of the three protrusions 7 illustrated in the left side of the groove 5, two protrusions 7 on the side closer to the groove 5 corresponds to the projections T, the convex portion 7 farthest from the groove 5, the virtual plane 2a since high, but does not exceed h / 10, it does not correspond to the projection T.
[0027]
　Figure 4A is shown the groove 5 is one of the recesses 6. The recess 6, the height of the Z direction is a region lower than the virtual plane 2a, grooves 5 are also included in the recess 6. Not only roughness intended to control, area lower than the virtual plane 2a due unintentional flaws or small surface variations and measurement errors are included in the recess 6. Groove 5 is a recess 6 for magnetic domain control, which is formed on the surface of the steel sheet 1, it can be clearly distinguished from the other recess 6.
[0028]
　As shown in FIG. 4A, a plurality of protrusions 7 are formed on both sides of the groove 5. Among them, reference numeral T in the convex portion 7 corresponding to the projections T. Projection T is the time of forming the grooves 5 by laser irradiation, the molten iron is heated by the laser is discharged from the groove 5, the molten iron was formed by depositing and solidifying on the surface of the steel sheet. Thus, the projections T is made of steel having substantially the same composition as the chemical composition of the steel sheet 1. Of course the convex portion 7 is also made of steel having substantially the same composition as the chemical composition of the steel sheet 1. The cross-sectional contour surface of the steel sheet in the cross-section shown in FIGS. 4A and 4B in the present embodiment contour curve QZ 2 is referred to as. Profile curve QZ 2 will be described later.
[0029]
　5, the range of grain-oriented electrical steel sheet of the present invention, the one groove 5, a diagram viewed in cross section perpendicular to Mizonobe extension direction Y. Similar to the grain-oriented electrical steel sheet 10, is formed with a plurality of protrusions 7 on the outer surface of the steel sheet in the groove width direction of the groove 5, a number of which corresponds to the projection T. However, the grain-oriented electrical steel sheet 20, forming positions of the projections T is, when compared to FIGS. 4A and 4B are separated from the groove 5, and a random. Furthermore, for the size distribution is not that large close to the groove 5, the second and subsequent n-th in the direction away from the groove 5 projections T n (n is an integer of 2 or more) to a maximum It may become a. More specifically, in the grain-oriented electrical steel sheet 20, from the groove 5 second projections T 2 width W of 2 is, projections T of one pawl from groove 1 the width W of 1 is greater than. That, W 2 / W 1 value of is set to greater than 1.0. Moreover, the projections T 1 groove 5 side end T of 1s projections T of the groove 5 1 a distance L between the end portion m of side s is in 40μm greater.
[0030]
　Figure 6 is a diagram of one projection T in grain-oriented electrical steel sheet 10, as viewed in cross-section including the Mizonobe extension direction Y and the thickness direction Z. In the present embodiment, the cross-sectional shape of the roughness curve YZ projections T in cross-section shown in FIG. 6 3 is referred to as. Roughness curve YZ 3 will be described later.
[0031]
　Oriented magnetic steel sheet 10, as a characteristic configuration for obtaining the effects, has the following five configurations (A) ~ (E).
　(A) based on the virtual plane 2a, the space volume of the recesses 6 and V1, the volume of the convex portion 7 is taken as V2, the value of V2 / V1 is within the predetermined range.
　(B) closest to the projection T on the grooves 5 1 width W of 1 is greater than the width of the other protrusions. Preferably, the height of the protrusions 7, the protrusions T 1 distance L from the groove 5 of the s and the projection T 1 width W of 1 is within the predetermined range.
　(C) Mizonobe in the groove longitudinal cross section parallel to the extending direction and the thickness direction, the value of the average height is largest area surface roughness parameter indicating the surface roughness of the Y-direction (Ra, RSm) is within a predetermined range is there.
　(D) Preferably, the metal structure of each projection T has substantially coincident with a metal steel sheet 1.
　(E), preferably, also the surface and the surface of the groove 5 of each projection T, similar to the coating and the steel sheet surface is formed.
[0032]
　It will be described in detail for each of the above configuration (A) ~ (E).
[0033]
Structure (A) for]
　In the present embodiment, the total pore volume of the recess 6 which is recessed from the imaginary plane 2a is V1, when the total volume of the convex portion 7 which projects from the virtual plane 2a was V2, V2 / V1 value is less than 0.10 ultra 0.80.
[0034]
　When forming the grooves 5 by laser irradiation in a known manner, the metal of the irradiated portion is melted or evaporated, a portion is lost from the irradiation portion by scattering in a space becomes droplets or fumes, recesses 6 is formed. Projection T is a metal that has been removed with the formation of the groove 5 is formed a convex portion 7 attached to the periphery of the groove 5. Therefore, the value of V2 / V1 is not to become greater than 1.0, not lowered significantly from 1.0. When forming a practical directional grooves in known laser irradiation conditions to obtain a magnetic domain control effect of the degree required by the electrical steel sheet, the amount of scattered space fume is less than 10%, V2 / V1 value is smaller by at most about 0.90, it is difficult to make this ratio to less than 0.90 by scattering of fumes. Although the laser irradiation and has been devised a means to blow away the molten material by blowing an assist gas at the same time, but still it is difficult to be less than 0.85.
[0035]
　To obtain the magnetic domain control effect for the purpose is required grooves 5 of constant depth and width. It is necessary to remove a certain amount of metal in other words. That the value of V2 / V1 can be less than 1, a constant magnetic domain control effect, i.e. in the case of forming the grooves 5 of constant depth and width, which means that the projections T can relatively small. Projection T as described above, since not desirable for the magnetic properties of the steel sheet 1, it is preferable the value of V2 / V1 is small, and less than 0.80 in the present embodiment, preferably less than 0.70, more preferably It should be less than 0.60. By applying the manufacturing method described later, to the value of V2 / V1 to less than 0.50 is not difficult, it is also be less than 0.40. As a result, insulation and rust resistance of a grain-oriented electrical steel sheet in which the grooves 5 on the surface of the steel sheet 1 is formed for domain refining is improved. On the other hand, the projection T may contribute to the improvement of the adhesion of the insulating film. The V2 / the value of V1 is 0.10 or less can not be obtained sufficient adhesion projections T is too small. Therefore, the value of V2 / V1 is 0.10 greater.
[0036]
Structure (B) for]
　In the present embodiment, in a specific region described below, the closest projection T on the grooves 5 1 width W of 1 is greater than the width of the other protrusions. That is, in a particular region, in a direction away outside the groove width direction of the groove 5, all the projections T appearing in the second and subsequent n For (n is an integer of 2 or more), the width W n are W n / W 1 orientation. These, but also a partly hinder domain wall motion described above, it is possible to reduce the adverse effects of a failure of the magnetic wall displacement if the metal structure of protrusions T to close to the metal steel sheet 1.
[0044]
　Basically it is effective to increase the crystal grain size of the projection T. Steel plate 1 which constitutes the oriented magnetic steel sheet 10 is composed of crystal grains of several 10mm units. Therefore, the size of the crystal grains constituting the projections T also, given the size of the Mizonobe extending direction Y, the crystal grains in the projection T along the groove 5 formed in a length of several mm ~ number 10 mm, extending it is also possible to grow up to a size comparable to the extending direction. However, assuming that the size of the Z-direction and the Q direction of the projection T is about several [mu] m, anisotropy also becomes size of several 10mm in the Y direction is generally isotropic large grains to a reasonable defined in crystal grain size is set to is also believed difficult. Since further vary wide size range of the projection T itself also considered it is not appropriate to be defined by the crystal grain size uniform. Therefore, in the present embodiment determines the degree of grain growth in the projections in the average number of crystal grains in the metal structure of protrusions T when observed in a cross section perpendicular (groove widthwise cross section) in the Mizonobe extension direction Y. Tissue molten iron scattered in the formation of the groove 5 in the conventional method is obtained by rapid solidification is formed in very fine crystal grains. The number of crystal grains at the bottom of the projection T is also the number 10 in the groove widthwise cross section. If the projections T is made from such fine grains, {110} <001> departing from the azimuth crystal grains contains a large amount. On the other hand, by applying the manufacturing method described below, it is possible to configure the projection T from coarse crystal grains, the number of crystal grains present in the bottom of the highest elevation T in the groove widthwise cross-section average it can be 10.0 or less. Method of measuring the number of crystal grains will be described later, in the average number of crystal grains 10.0 greater, there is a {110} <001> may include the number deviating grain from the azimuth. Therefore, the average number of crystal grains is preferably 10.0 or less, more preferably 5.0 or less, further preferably 3.0 or less. It is most preferred that the projections T is made of a single crystal grain.
[0045]
　Also, adverse effects of a failure of the magnetic wall displacement of the projection T is considered to be dependent on the crystal orientation. Crystal orientation of the projection T is, if the same crystal orientation continuous steel plate 1, hindrance effect of domain wall motion can be as small as possible. Since growing larger so-called Goss orientation in secondary recrystallization in the steel plate 1, by forming the groove 5 and the projection T in the previous step than this, the projection T is a steel plate 1 side in the process of secondary recrystallization can be encroachment by the Goss orientation has grown, it the preferred crystal orientation of the projections T.
[0046]
Structure (E) for]
　FIG. 4A, FIG. 4B and FIG. 6, but illustrates a state in which there is no film on the steel sheet surface, including the surface of the groove 5 and the projection T, oriented electrical steel sheet of the present embodiment in the surface of the recess 6 and the projection 7 may be covered with a glass coating. In particular, be in a form glass coating film is interposed between the insulating film and the steel sheet 1, it is possible to ensure the adhesion of the steel sheet 1 and the insulating film, thereby improving the rust resistance and insulating properties. In the process of forming grooves by laser irradiation after the formation of the insulating film, resulting in abolished insulating film and glass coating film in the groove 5. For rust resistance and insulating securing, the insulating film after the formation of the grooves are again formed, in this case, since the surface of the groove 5 to contact directly the insulating film on the steel sheet, adhesion sufficient insulation coating it may not be possible to secure.
[0047]
　Although details will be described later, in a state where annealing prior to application of the separating agent previously formed grooves 5 and the projection T, on the surface of the surface and the projections T of the groove 5 was coated with an annealing separating agent for the formation of the glass coating film by performing the finish annealing, it is possible to form a glass coating film on the surface of the inner surface and the projections T of the groove 5. Glass coating film need not be special, for example, the thickness of the glass coating film is greater than 0 ~ 5 [mu] m, the thickness of the insulating coating may be applied a coating of 1 ~ 5 [mu] m. Further, no glass film, arranged so as to ensure adhesion of the insulating coating on the steel plate 1, can also be applied to so-called glass-less coating. Incidentally, these coatings, the surface of the groove 5, the surface of the projections T, the flat portion (steel sheet surface matches the virtual plane will be described later), they need not be the same thickness. These coatings, the liquid material is coated on the surface of the steel sheet, drying, because it is formed by baking, it is natural groove 5 and the projections T of a thickness of the unevenness of the surface changes. These changes thicknesses are not to lose the effect of the present invention.
[0048]
　As described above, by a form having a glass film or an insulating film, since the film crack and delamination at the periphery around the groove 5 and the projection T is less likely to occur, adhesion of better insulation coating it is possible to obtain.
[0049]
　Incidentally, in the description of the configuration of the above (A) ~ (E), the space volume V1 of the recessed portion 6, the volume V2 of the projections 7, the convex portions 7 and the height of the projections T, the width W of the projections T, the projection T 1 the distance L between the groove 5 s , such as crystal grain size of the metal structure in the projection T, for convenience, have been described the characteristics of one specific section in mind. However, as shown in FIG. 6, in the extending direction of the groove 5 (Y-direction), the shape of the projection T is not necessarily constant. Similarly, it changes greatly depending sectional observing the crystal grain size and crystal orientation distribution of the metal structure of the width W and the projections T of the projection T. Therefore, hereinafter, it is described a specific method of quantitative value relating to the shape of the surface of the steel sheet in the present invention.
[0050]
　Note that values ​​for various steel surface profile defined in the present invention, without considering about the film on the surface of grain-oriented electrical steel sheet, which should be identified in the surface of the steel sheet 1. That is, provisions concerning the shape of the present invention are those of the steel plate 1 except the film, for grain-oriented electrical steel sheet having a coating, the measurement of the steel sheet 1 on the surface by cross-section observation, or the steel plate 1 after removal of the film it is in those to be measured. To be conveniently obtained the required measurements in the present invention is to identify the surface of the steel sheet 1 by cross-sectional observation, than obtain measurements necessary based on it, the shape of the steel sheet 1 on the surface of the absence of the film state methods of measuring three-dimensionally the are suitable. Hereinafter will be described the method.
[0051]
　In the present invention, includes a groove 5 and projections T, the Z-direction position of a sufficiently wide range of the steel sheet surface is measured by using a laser type surface roughness measuring instrument. In the present invention, unevenness of the size and surface of the projection T to be controlled, in consideration of the formation position, over the range of 1000μm for the extending direction Y of the groove 5, the Q direction groove as the center 400 [mu] m (the groove of the range of 200 [mu] m) and a specific region on one side, the Z-direction position of the surface of the steel plate 1 measured at constant intervals in this particular area, obtain the height distribution of the height data. In this measurement, the following 0.40 .mu.m laser spot diameter (e.g. 0.40 .mu.m), and scanning in steps of less than 0.30 .mu.m in the Y direction (e.g. 0.15 [mu] m), 0.30 .mu.m or less in the Q direction (e.g., 0. scanned in steps of 15 [mu] m), 0.10 .mu.m or less the measurement accuracy of the Z direction (for example 0.10 .mu.m), and 50 times the magnification of the objective lens.
[0052]
　Depending on the scanning step, but this manner, a surface shape data consisting of total 10 million or more points from the entire area of ​​the specific region. Then, we aggregate the data as frequency distribution of each Z-direction height. Then, the defining a height maximal frequency as a virtual plane 2a, considered an ideal reference plane that matches the surface of the steel sheet before the formation of the groove 5 and projections T, and zero Z-direction height. Width of the groove 5 serving as a recessed area as Z-direction height is about 20 [mu] m, also large areas of about near 400μm area also groove 5 in which the metal scattered from this region is the projection T is deposited on the surface of the steel sheet not that spread thinly over the entire surface given the are those localized, even when there is slight unevenness in addition the surface of the flat portion of the original steel plate 1, the original steel sheet surface in the above frequency (in the Z-direction the height identifies the virtual plane 2a regarded as zero) is considered appropriate.
[0053]
　The virtual plane 2a, for an area where there is a groove 5 and projections T, assuming a stretched flat. Figure 4A, 4B and FIG. 6 depicts a virtual plane 2a that is determined in this way by a chain line. By determining such plane, the space volume V1 of the metal has been removed as a groove 5, the measurement point Z direction height is a negative value, to sum the product of step width and Z-direction height in can be identified. Similarly, the volume V2 which a convex portion 7 molten iron from the steel sheet surface as a projection T is discharged, the measurement point Z direction height becomes a positive value, the product of step width and Z-direction height It can be identified by the total.
[0054]
　Related to the height of the convex portion 7 "h" side by side above the surface shape data in descending order of the Z-direction height, ranking is specified as the height to be 0.02% of the total. For example, in the case of data 10 million points, a height to the height of 2000 th measurement point and h.
[0055]
　The actual height of the protrusions 7 can be considered from 0 than the various heights, but in the present invention is used to represent an order of magnitude of the convex portion 7 by h. The h height, is in the convex portion 7 existing number is considered to be a value corresponding to the height of the relatively tall protrusions 7 but, characteristic of interest, i.e. the insulating property, rust resistance , magnetic properties, considering from being strongly influenced by the relatively tall protrusions 7, such an assessment is considered reasonable.
[0056]
　Other To identify the specified value in the present invention, the curve representing the steel sheet surface in the Y-direction vertical section (groove widthwise cross section) and Q directions vertical section (groove lengthwise section) is used. In the following first described how to obtain these curves.
[0057]
　Among the surface shape data, a series of data Y-direction position is the same, namely profile curve QZ represents the change in height in the height data at a particular QZ section 1 obtained. The profile curve QZ 1 By averaging for every Y-direction position, contour curve QZ forming an average contour of the Q direction 2 is obtained (Fig.
[0058]
　Similarly among the surface shape data, a series of data Q direction position is the same, namely profile curve YZ represents the change in height in the height data at a particular YZ section 1 obtained. Furthermore sectional curve YZ in particular Q direction position 1 for each, an average Za height. Sectional curve YZ 1 among the profile curve average Za is maximum contour curve YZ 2 is. Contour curve YZ 2 , the average height of the extending direction Y corresponds to the contour curve of the highest region in the height distribution.
[0059]
　Contour curve YZ 2 position of the Q direction is obtained, seen as, contour curve QZ from the above defined 2 Z-direction height is the best match a position at. And this position is usually projections T of below 1 the position of the top of. Contour curve YZ 2 by applying a high-pass filter of the low-pass filter and a cutoff value λc cutoff value λs, the roughness curve YZ 3 give (Figure
[0060]
　Cutoff values ​​λs and λc is determined by the type and the objective lens of the laser type surface roughness measuring instrument. In the present invention, as the cut-off value when measuring roughness magnification of the objective lens as a 50-fold with Keyence Corporation of VK-9700, λs = 0.8μm, using [lambda] c = 0.08 mm.
[0061]
　Next will be described a procedure for identifying the prescribed value used in the present invention from these curves.
[0062]
　Contour curve QZ 2 from identifies the specified value related to the distance from the width and the groove 5 of the projection T.
[0063]
　Contour curve QZ 2 is, Q direction center, i.e. in the direction away from the central portion of the groove 5, the point of intersection to the virtual plane 2a and the first and groove end point m. Defining a projection T in a region away from the groove than the groove end point m. The protrusion T in this specification, the contour curve QZ 2 has a height of a position higher than the height of h / 10, and contour curve QZ 2 Distance Q direction height is continued at h / 10 or h is a more regions. The reason for specifying the projection T in such a provision, there are different irregularities and unevenness to be controlled intended to in order to obtain the effect of the present invention the surface of the steel sheet 1, in the present invention this unintended irregularities it is to exclude from be defined projection. Irregularities to be excluded or a fine irregularities appearing like rolling (roughness), such as numbers variation is considered due to the measurement error. These are very fine, according to current industrial manufacturing techniques and measurement accuracy, as described above, the profile curve QZ the raw data 1 the average Y direction position profile curve QZ 2 a considered the significant part disappeared in obtaining treatment but is intended to further exclude irregularities is compared with the height h of relatively small height and width as described above from the evaluation target.
[0064]
　In the present invention, in the direction it is moving away to the outside of the groove 5 in the direction Q from the groove end point m, to number the projections in order from the side closer to the groove. n prong T n in the projections T n position T on the side of the end points closer to the groove of ns , the position on the far side of the end point of the groove T ne as, T ns and T ne distance projections T between n of width W N is. End point T ns and T ne , respectively, virtual surface and the contour curve QZ at a height of h / 10 2 which is an intersection with. In the present invention, the closest projection T on the grooves 1 the width of W 1 and. The protrusion T closest to the groove 5 1 For, groove end points m and T 1s distance between the L s is.
[0065]
　Roughness curve YZ 3 from the average height of the Y direction determining an average length RSm of the average roughness Ra and roughness curve element of highest elevation T. Average length RSm of the average roughness Ra and roughness curve element is determined in accordance with Japanese Industrial Standard JIS B 0601 (2013).
[0066]
　The average number of crystal grains forming the projections T is determined from the cross section perpendicular to the Mizonobe extension direction Y (groove widthwise sectional, Q-Z plane). In the present invention, as shown in FIG. 7A, to observe the metal structure of the groove widthwise sectional at 10 observation points 31-40 in the Y direction, present in the bottom of the highest elevation T in each of the observation points 31-40 determine the number of crystal grains. That is, as shown in FIG. 7B, determining the number of crystal grains Z direction height of the projections T in the groove widthwise cross-section present on the line 41 of the h / 10. Then, to calculate the number of crystal grains of an average value for each observation point 31-40. Although the means for observing the metallic structure steel plate 1 are possible by known means, the groove size of the projections in the lateral cross section so several [mu] m, a scanning electron microscope: it is preferable to observe the (Scanning Electron Microscope SEM) .
[0067]
　The crystal orientation in the projection T is contour curve YZ 2 determined by observing the cross section of the metal structure obtained. Note Of cross-sectional structure, the region corresponding to the projections T, i.e., is to determine the crystal orientation is limited only to the region Z direction height is h / 10. Crystal orientation electron backscatter diffraction (Electron Back Scattering Diffraction Pattern: EBSD ) by methods, obtaining the {110} <001> orientation area ratio of the corresponding region.
[0068]
　The measurement conditions of EBSD shall be as follows.
　(A) Measuring device: an electron backscatter diffraction apparatus with a scanning electron microscope
(SEM-EBSD) (model number "JSM-6400" in the SEM (JEOL
　Ltd.)) (b) Beam diameter: 0.5 [mu] m
　(c) Step interval: 0.1 [mu] m
　(d) magnification: 100-fold
　(e) measurement area: contour curve YZ 2 a cross-section to obtain a 1000μm in the Y direction
　for the region corresponding to the projections T measured under the above conditions, {110} <001 > the area ratio of a region which is (± 10 °) orientation and the area ratio in the present invention. Area ratio preferable in that more than 65% can be improved magnetic properties. That is, the crystal orientation of the metal structure of protrusions T height Mizonobe average height highest region of the extending direction Y in the distribution, it is preferable that the {100} <001> orientation area ratio of 65% or more.
[0069]
　The measurement of these projections T are suffices for only one side in the region of the groove 5. Figures for the above projections T are apt to be equal on both sides of the groove 5, also, even if there is a deviation, if the condition is satisfied on one side, because the effect of the present invention is obtained.
[0070]
　For Mizonobe extending direction, specified value of the projection T is measured in the vicinity of the center of the extending direction. This than towards the edge of the extension of the groove 5 by a change in the laser irradiation angle, the shallower the depth of the groove 5 gets closer towards the end of the extension is due to the greater variation of the shape of the projection T.
[0071]
　Further, since the present invention the grooves 5 need not be linear, in the measurement of the surface height Z by the three-dimensional roughness meter of the length direction of 1000μm in the Y-direction and the measurement area is strictly match it is conceivable that you do not. However, even in a groove 5 formed in a curved shape, for groove 5 prepared in a practical range as an industrial product, if the distance of the order of 1000 .mu.m, not permissible as a substantially straight, so in the present invention to define the features in the.
[0072]
　With respect to the variation in the plurality of grooves 5 is not particularly necessary to consider for such determination by and outliers in the range of manufacturing variation of the industrial products. The provisions of the present invention uses a value obtained by averaging the length over 1mm in the extending direction, which is assumed to typical values ​​are obtained just as much is no problem for the variations in the individual grooves every five.
[0073]
　Incidentally, the projections 5 that are defined in the present invention is a surface shape of the steel sheet 1. That is, not in the form of the top of the film of oriented electrical steel sheet having a coating. It be coating formed on the surface of the steel sheet 1, by performing cross-section observation, it is possible to measure visually. However, to quantify the various values, it is good operability for measuring the surface shape using the three-dimensional roughness measuring apparatus, as described above, the surface of the steel sheet 1 in a state the absence of coating if it is necessary to measure. If this is to form the grooves 5 and the projection T prior to formation of the film, may be measured before forming or immediately after film-forming. Also, if measured after the film formation, the glass coating film and an insulating film of grain-oriented electrical steel sheet, for example, can be measured by removing the following manner.
[0074]
　Oriented electrical steel sheet having a glass coating film or an insulating film, NaOH: 10% by mass + H 2 O: 90 wt% aqueous sodium hydroxide for 15 minutes at 80 ° C., immersion. Then, H 2 SO 4 : 10 wt% + H 2 O: 90 wt% aqueous solution of sulfuric acid, 3 minutes at 80 ° C., immersion. Thereafter, HNO 3 : 10 wt% + H 2 O: by the 90 wt% nitric acid aqueous solution, 1 minute weak at room temperature, washed immersed in. Finally, one minute less than with a blower of hot air and dried.
[0075]
　Note that when removing the glass coating film or the insulating coating from the grain oriented electrical steel sheets by the method described above, the shape and roughness of the groove 5 of the steel plate 1, it is confirmed that a comparable prior to forming the glass coating film or an insulating film ing. The grooves 5 formed further in the course of the steel sheet production process, after which a large deformation such as cold rolling is performed while the shape varies greatly, pass through these processes if such annealing and film formation even if it has been confirmed that the change of the shape is small. In the present invention, provisions for projection T is intended to apply to the final product, if film on the surface of the final product is formed, shall apply to the steel plate 1 was peeled off it.
[0076]
　It relates chemical composition, the steel sheet 1 is, for example, by mass%, Si: 0.8 ~ 7%, C: 0 super ~ 0.085%, acid-soluble Al: 0 ~ 0.065%, N: 0 ~ 0. 012%, Mn: 0 ~ 1%, Cr: 0 ~ 0.3%, Cu: 0 ~ 0.4%, P: 0 ~ 0.5%, Sn: 0 ~ 0.3%, Sb: 0 ~ 0.3%, Ni: 0 ~ 1%, S: 0 ~ 0.015%, Se: 0 ~ 0.015%, contains, with the balance being Fe and impurities.
[0077]
　Chemical composition of the steel plate 1 is a preferred chemical components to control the Goss texture was integrated crystal orientation {110} in the <001> orientation. Among the elements, Si and C is an essential element, acid-soluble Al, N, Mn, Cr, Cu, P, Sn, Sb, Ni, S, and Se are a selective element. Additional optional elements are not necessary to limit the lower limit value so may be contained according to the purpose, the lower limit value may be 0%. As the selective element is not limited to the above elements, known elements having a known effect in oriented electrical steel sheet be contained in a known range, the effect of the present embodiment is not impaired. For example, the balance of the essential elements and selective elements of the steel sheet 1 is composed of Fe and impurities. The impurities, in producing the steel sheet 1 industrially means inevitably mixed elemental ore as a raw material, scrap, or from the manufacturing environment and the like.
[0078]
　Further, the grain-oriented electrical steel sheet, it is common to undergo purification annealing during secondary recrystallization. Emissions to the outside of the system of the inhibitor-forming element occurs in the purification annealing. In particular N, decrease in concentration pronounced for S, it becomes 50ppm or less. If ordinary purification annealing conditions, N, S respectively 9ppm less, more 6ppm or less, if sufficiently performed purification annealing, a general analysis reaches a degree that can not be detected (1 ppm or less).
[0079]
　Chemical composition of the steel sheet 1 may be measured by general analytical methods of steel. For example, the chemical components of the steel sheet 1 may be measured using an ICP-AES (Inductively Coupled Plasma-Atomic Emission Spectrometry). Specifically, a test piece of 35mm angle of the steel plate 1 after film removal, by Shimadzu ICPS-8100, etc. (measurement apparatus) can be identified by measuring in a condition based on a calibration curve prepared in advance. Incidentally, C and S combustion - infrared absorption method using, N is the inert gas fusion - can be measured with a thermal conductivity method.
[0080]
　As described above, according to this embodiment, rust resistance and insulation properties further oriented electrical steel sheet groove 5 and projections T on the surface of the steel sheet is formed for magnetic domain subdivision significantly improve the magnetic properties It is possible.
[0081]
　Next, a method for manufacturing a grain-oriented electrical steel sheet according to the embodiment of the present invention. Figure 8 is a flowchart illustrating a method of manufacturing a grain-oriented electrical steel sheet according to the embodiment of the present invention. This manufacturing method, as shown in FIG. 8, the casting process S01, the hot rolling step S02, the annealing step S03, the cold rolling step S04, decarburization annealing step S05, annealing separator application step S06, finish annealing step S07, insulation comprising a film forming step S08 and the laser irradiation step S99. Although point of this manufacturing method is a groove formed (projections forming) step by laser irradiation, this step can be carried out at a plurality of timings of steel sheet production process over a number of steps. Therefore, in the following description, first describing the manufacturing method of a typical grain oriented electrical steel sheet, then, a description will be given of a laser irradiation step S99 of forming the grooves and the projections.
[0082]
　In the casting step S01, for example, by mass%, Si: 0.8 ~ 7%, C: 0 super ~ 0.085%, acid-soluble Al: 0 ~ 0.065%, N: 0 ~ 0.012%, Mn: 0 ~ 1%, Cr: 0 ~ 0.3%, Cu: 0 ~ 0.4%, P: 0 ~ 0.5%, Sn: 0 ~ 0.3%, Sb: 0 ~ 0.3 %, Ni: 0 ~ 1%, S: 0 ~ 0.015%, Se: 0 ~ 0.015%, containing, molten steel having a chemical composition the balance being Fe and impurities is fed to a continuous casting machine Te, the slab is issued manufactured continuously.
[0083]
　Subsequently, the hot-rolling step S02, after the slab obtained in the casting step S01 is heated to a predetermined temperature (e.g. 1150 ~ 1400 ° C.), the hot rolling is performed. Thus, for example, hot-rolled steel sheet is obtained having a thickness of 1.8 ~ 3.5 mm.
[0084]
　Subsequently, the annealing step S03, with respect to hot-rolled steel sheet obtained by the hot rolling step S02, annealing is performed at a predetermined temperature (e.g., conditions of heating at 750 - 1200 ° C. 30 seconds to 10 minutes) . Subsequently, the cold-rolling step S04, after the hot-rolled steel sheet annealing process is performed in the annealing process S03 were pickled, cold rolling is performed. Thus, for example, cold rolled steel sheet is obtained having a thickness of 0.15 ~ 0.35 mm.
[0085]
　Subsequently, the decarburization annealing step S05, with respect to cold-rolled steel sheet obtained from the cold-rolling step S04, the heat treatment of a predetermined condition (e.g., heating 1-3 minutes at 700 ~ 900 ° C.) (i.e., decarburization annealing processing) is performed. When such decarburization annealing process is performed, in cold-rolled steel sheet, the carbon is reduced below a predetermined amount, the primary recrystallization structure is formed. In the decarburization annealing step S05, the surface of the cold rolled steel sheet, silica (SiO 2 oxide layer containing) Further, subsequent inhibitors of secondary recrystallization of the grain-oriented electrical steel sheet to decarburization annealing, may be formed by nitriding annealing. If the application of this technique, subsequently carrying out the nitriding annealing decarburization annealing step S05. Here, also such nitriding annealing is described including the decarburization annealing step S05.
[0086]
　Then, the annealing separator application step S06, the annealing separator containing magnesia (MgO) as the main component, is applied to the surface (the surface of the oxide layer) of the cold-rolled steel sheet. Subsequently, the final annealing step S07, with respect to cold-rolled steel sheet annealing separator is applied, the heat treatment of a predetermined condition (e.g., heating 1100 ~ 1300 ° C. for 20 to 24 hours) (i.e., finish annealing process) is performed It is. If such final annealing process is performed, the secondary recrystallization with resulting cold-rolled steel sheets, cold-rolled steel sheet is purified. As a result, has a chemical composition of the steel sheet 1 described above, cold-rolled steel sheet crystal orientation is controlled so that the crystal grains of the easy magnetization axis and the rolling direction X matches is obtained.
[0087]
　Further, when such final annealing process as described above is performed, an oxide layer containing silica as a main component reacts with annealing separator containing magnesia as a main component, for example on the surface of the cold rolled steel sheet, forsterite (Mg 2 SiO 4 ), spinel (MgAl 2 O 4 ), or cordierite (Mg 2 Al 4 Si 5 O 16 glass coating film containing a composite oxide such) is formed. In the finish annealing step S07, finish annealing process is performed in a state where the cold-rolled steel sheet is coiled. By glass film on the surface of the cold rolled steel sheet is formed in the final annealing process, it is possible to prevent the seizure of the cold-rolled steel sheet coiled.
[0088]
　Subsequently, the insulating film forming step S08, for example, an insulating coating solution containing colloidal silica and phosphate is coated over the glass coating film. Thereafter, baking heat treatment is carried out under a predetermined temperature condition (e.g., 840 ~ 920 ℃).
[0089]
　Next, a description will be given of a laser irradiation step S99. Laser irradiation step S99, the casting process S01 and later, it is possible to implement in any timing, groove 5 and projections T of at most about several 100μm as a change in surface shape, after which hot rolling, pickling, When carrying out the cold rolling, resulting in almost disappeared. Therefore, it should be performed after at least cold rolling step S04. First, a description will be given feature appearing by execution timing of the laser irradiation step S99.
[0090]
　If the laser irradiation step S99 performed between the cold rolling steps S04 and decarburization annealing step S05, together with the rolling oil present on the surface of the steel sheet in a state in rolling acts effectively on the shape control of the steel sheet surface, the grooves 5 and the surface of the projection T also silica (SiO produced during decarburization annealing step 2 oxide layer containing) Therefore, it is advantageous for formation of a good glass film in final product. Further, if not up to the flat portion of the steel plate, the grain growth of the projection in the decarburization annealing step particle size is trimmed awake encroachment becomes liable to occur due to secondary recrystallized grains of a steel plate in the finish annealing.
[0091]
　If a process employing a nitride annealing may be performed with a laser irradiation step S99 during the decarburization annealing step S05. By performing laser irradiation before the nitriding annealing, since the surface layer region and the region of the projections T of the groove 5 even inhibitor controlled by the nitriding is performed tissue, the crystal orientation in the subsequent secondary recrystallization for these regions it is expected that preferably controlled. However, in general, nitriding annealing is carried out so as to avoid an increase in energy costs by performing without lowering after decarburization annealing, the steel sheet temperature. To perform laser irradiation in this way, once it cooled steel sheet after the laser irradiation, to yield the need to reheat for nitriding, dare about carried out at this timing should take this into account .
[0092]
　When carrying out the laser irradiation step S99 between the decarburization annealing step S05 the annealing separator application step S06, it is possible to form a glass coating film on the surface of the groove 5 and the projection T. However, since the surface and the surface of the projection T of the groove 5 are oxide layer mainly composed of silica were formed in the decarburization annealing step S05 disappears, the ones not preferable as the state of the glass coating film . Also, if you have performed inhibitor control was carried out nitriding annealing, the surface area and projection area T of the groove 5 is not turned to the inhibitor are preferred conditions, the Goss orientation as a preferred crystallographic orientation from this region secondary recrystallization can not be expected. However, since at least the final annealing step S07 becomes after outgrowth, encroachment by the secondary recrystallized grains from the grain growth and the steel sheet of the metal structure of protrusions T can be expected.
[0093]
　If the laser irradiation step S99 performed between the annealing separator application step S06 and the finish annealing step S07, since the annealing separator in a liquid state is effectively acting on the shape control of the steel sheet surface, the laser before drying the annealing separator irradiation should be performed. Although annealing separator which had been applied to the surface of the groove 5 immediately after laser irradiation become dissipated, annealing separator is, so long as the state, the surface of the groove 5 is again covered with annealing separator. However, the molten iron has solidified rides on the annealing separator may have a considerable Zaru affect the subsequent glass coating film formation, it is necessary to be careful that there is a concern that cause localized coating failure.
[0094]
　If the annealing step S07 finishing the laser irradiation step S99 performed between the insulating film forming step S08, since in the surface of the groove 5 and the projection T insulating coating is formed, it can benefit for film adhesion.
[0095]
　Laser irradiation step S99 can be also be carried out in the insulating film forming step S08. Insulating film forming step S08, the insulation coating solution was applied to steel plates, but carrying out the baking heat treatment, an insulating coating solution can be utilized to control the steel sheet surface condition of the present invention. After applying the insulating coating solution, the laser irradiation is performed prior to baking heat treatment, then performing baking heat treatment. In this case, although the glass coating film is not present on the surface of the groove 5 and the projection T, anyway insulating film is formed. Benefits of reformation of the insulating film which is required in the case of forming the groove 5 and the projection T in the final product is not required is.
[0096]
　When carrying out the laser irradiation step S99 after the insulating film forming step S08, no longer exists insulating film on the surface of the groove 5 and projections T, the rust resistance and insulation property of the insulating film for securing as described above since re-formation is required, there is no merit dare performed in this step.
[0097]
　Further consideration, in order to control the shape of the steel sheet surface, when carrying out the laser irradiation step S99 in a state coated with any substance, as described below, depending on the material to be coated as in the timing of the laser irradiation step S99 is is that required to remove the coating material after the laser irradiation occurs. For example, between the decarburization annealing and nitriding annealing, the case of controlling the shape of the steel sheet surface in a state where the oil was applied by laser irradiation, if there is a problem in implementing the nitriding annealing while oil adheres, laser it is necessary to perform the nitriding annealing after removing the oil, such as by Tsuban electrolytic degreasing line after irradiation.
[0098]
　In this regard, the case of utilizing the rolling oil between the cold rolling steps S04 and decarburization annealing step S05 as the coating material, the coating material with an annealing separator agent in the liquid state between the annealing step S07 finish the annealing separator application step S06 If utilized as, to take advantage of the middle insulating coating liquid insulation coating formation step S08 as the coating material, it is advantageous because there is no need of removal of the coating material.
[0099]
　Considering the points described above, the laser irradiation step S99, as shown in FIG. 8, it is particularly preferable to perform between the cold rolling steps S04 and decarburization annealing step S05. Further, described below, as a method for forming the characteristic projections in the present invention, in the case of employing the means of oil applied to the steel sheet surface is irradiated with a laser, steel sheet after cold rolling is inevitably steel sheet rolling oil because it is covered with, it is also very convenient in this regard.
[0100]
　Here, a description will be given of a laser irradiation step S99. In the laser irradiation step S99, on which a particular substance is applied to the surface of the steel sheet, the laser is radiated toward the surface of the steel sheet, the groove 5 is formed on the surface of the steel sheet. Projections T are formed with the formation of the groove 5. Although will be described later the specific substance, the specific substance is a rolling oil used in example cold rolling. Laser control conditions need not be a special, known conditions are employed. By irradiating a laser onto the surface of the steel sheet, the surface of the steel sheet, a plurality of grooves 5 extending in a direction crossing the rolling direction, it is formed at predetermined intervals along the rolling direction. This example, a laser emitted from the laser light source, via an optical fiber to transmit the laser irradiation apparatus, by the polygon mirror and the rotation driving device irradiates toward a laser on the surface of the steel sheet, cold rolling the laser substantially a plate width direction of the steel sheet is formed by parallel scan.
[0101]
　Simultaneously with the laser irradiation, an assist gas such as air or an inert gas may be blown to the site where the laser of the steel sheet is irradiated. Assist gas is responsible for removing the scattered or vaporized components from the steel sheet by laser irradiation.
[0102]
　By synchronously controlling the rotation speed of the polygon mirror, the conveying speed of the rolling direction of the steel sheet, a plurality of grooves 5 crossing the rolling direction, can be formed at predetermined intervals along the rolling direction.
[0103]
　As the laser light source can be used, for example a fiber laser. YAG laser, semiconductor laser, or CO 2 high-power laser may be used as a laser light source used for general industrial laser. The pulse laser, or may be used continuous wave laser as a laser light source. As the laser, light harvesting high, it is preferable to use a single mode laser suitable for the formation of the groove 5.
[0104]
　As the irradiation conditions of the laser, for example, to 200 ~ 2000 W laser power, focusing spot diameter in rolling direction of the laser (diameter containing 86% of the laser output) to 10 ~ 1000 .mu.m, the focusing spot in the plate width direction of the laser the diameter 10 ~ 1000 .mu.m, the laser scanning speed 5 ~ 100m / s, it is preferable to set the laser scanning pitch (interval) in 2 ~ 10 mm. Desired as groove depth is obtained, it may be suitably adjusted to these laser irradiation conditions in a known range. For example, in the case of obtaining a deeper groove depth is set slow laser scanning speed may be set higher laser output.
[0105]
　Next, a description will be given material (coating material) applied to the surface of the steel sheet during laser irradiation. Coating material is preferably a fat, water, alcohols, colloids, emulsions, annealing separator used in the manufacture of grain-oriented electrical steel sheet, and like liquid, such as an insulating coating solution material. When considering the materials used in the manufacture of general-oriented electrical steel sheets, oil that is used as rolling oil and rust preventive oil is easy to handle, and more preferably. Rolling oil does not need to be again applied after cold rolling, particularly preferred.
[0106]
　Coating material, the following two conditions are satisfied.
　(A) the viscosity is within a specific range, it is also a relatively small force in the liquid is a substance that instantaneously deformed.
　(B) is in the range thickness certain liquid film on the surface of the steel sheet after coating, it is possible to suppress the spread of the molten iron, when the part of the molten iron rides on of the liquid film, it is a substance that inhibits welding of the steel sheet in the molten iron by intervening between the steel plates.
[0107]
　In this way, it is possible to manufacture a grain-oriented electrical steel sheet according to the embodiment of the present invention. Steel 1 contained in the oriented electrical steel sheet, as chemical components, by mass%, Si: 0.8 ~ 7%, C: 0 super ~ 0.085%, acid-soluble Al: 0 - 0.065% N: 0 ~ 0.012%, Mn: 0 ~ 1%, Cr: 0 ~ 0.3%, Cu: 0 ~ 0.4%, P: 0 ~ 0.5%, Sn: 0 ~ 0.3 %, Sb: 0 ~ 0.3%, Ni: 0 ~ 1%, S: 0 ~ 0.015%, Se: 0 ~ 0.015%, contains, with the balance being Fe and impurities.
[0108]
　In this manufacturing method, if necessary, a brush cleaning step may further include a known manufacturing process to maintain some characteristics of the grain-oriented electrical steel sheet.
[0109]
　Hereinafter, the mechanism specific surface shape of the steel sheet 1 under the influence of coating material is obtained, and the preferred conditions for the coating material will be described.
[0110]
[The mechanism]
　is not clear is the mechanism that the present invention effects that you apply the specific substance on the surface of the steel sheet during laser irradiation can be obtained, as consistent with the results of the examination of the influence of various substances, at present It is considered to be as follows.
[0111]
　To form the groove domain control purposes, is irradiated with laser light 10 on the surface of the steel sheet 1, the steel of the illuminating part is instantaneously melted and scattered out of the illuminating part (FIG. 9A). Thus with groove 5 is formed in the, some of the molten iron 11 scattered protrusions such as the protrusions 7 are welded on the surface of the steel sheet is formed (FIG. 9B).
[0112]
　On the other hand, as shown in FIG. 9C, the coating material 12 on the surface of the steel sheet during the laser irradiation it is uniformly applied in a proper state, when the molten iron 11 is pushed around the groove 5, identified molten iron 11 scattering will be push the material 12 from the groove 5 can be suppressed. Thus molten iron 11 by a membrane of a specific substance 12 and is suppressed to be scattered far from the groove 5. Also, part of the molten iron 11 13 rides on the coating film of a specific substance 12. As shown in FIG. 9D, molten iron 13 rides on the coating film does not remain as a weld deposit to solidify exfoliated surface of the steel sheet on the coating film of a specific substance 12. Therefore, the total amount of the weld deposit decreases. Since no remaining as welding of the upper solidification exfoliated steel surface of the coating film of the weld deposit also specific substance 12 scattered to a point far away from the groove, the protrusion intended to close the groove (projection T 1 only) next, protrusion T 1 projections (projections T away from the groove than 2 width of later) projections T 1 becomes smaller than the width of the.
[0113]
　While that such weld deposits exert various harm by spreading next groove around protrusions 7 or projections T are as described above, the total amount is reduced scattering of weld deposit is limited to the peripheral groove in the present invention the reduction of the characteristic can be avoided by Rukoto.
[0114]
[Viscosity]
　Given the above mechanism, the coating material is may be defined by contact with the molten iron hot, which is not realistic. The present invention defines the invention in viscosity of the coating material in the state before laser irradiation.
[0115]
　The viscosity of the coating material is 100 mm 2 is preferably less / s. If any material that deforms with a force applied from the molten iron has a viscosity sufficient that applied, because the effect of the present invention are believed to be obtained, the lower limit is not particularly limited, if the viscosity is too high, such as coating handle not only difficult, interfere with moderate spread in the groove around the melt, together with the height h of the convex portion is deposited only in the immediate vicinity of the groove 5 becomes high, the desired V2 / V1 can not be obtained. The viscosity is suppressed from scattering from the groove of the molten iron is too low, decreases the effect of depositing the peripheral groove, the distance L s , it becomes difficult to control the projection width W within a specific range. The viscosity is preferably 10 ~ 70 mm 2 or less / s, more preferably 40 ~ 60 mm 2 is / s.
[0116]
　The viscosity can be controlled by changing the coating material, it is also possible to control by varying the example temperature or concentration. The temperature of the coating material is preferably 10 ~ 100 ° C.. Preferably 15 ~ 60 ° C., more preferably from 20 ~ 50 ° C.. The temperature affects the viscosity change is allowed by the invention the effect of the coating material, suitable temperature ranges are also the ease of temperature control and handling in the manufacturing process to be determined in consideration. If the coating material was an emulsion of oil or fat, the above temperature range matches the preferred ranges and schematic for viscosity.
[0117]
　If the coating material is a some mixture can be controlled to an appropriate viscosity easily temperature range handled by adjusting the concentration. Concentration in the case of applying the general direction colloidal solutions such as fat emulsions and used in the manufacturing process annealing separator and insulating coating solution of the electromagnetic steel sheet, if an emulsion of the oil, the sum of water and oil for 50 to 70% volume concentration of fat, if annealing separator agent 5% to 80% concentration of magnesia in water and magnesia, further if the insulating coating solution water and aluminum phosphate and colloidal silica and chromic acid at a concentration of aluminum phosphate and colloidal silica and chromic acid if 20-80% relative, it can be controlled in viscosity for obtaining preferably a projection control effect of the present invention. Of course appropriate concentration range, as well as adjustment of viscosity for obtaining the invention effects, it should consider the temperature control and ease of handling in the manufacturing process is the same as the temperature.
[0118]
[For coating thickness]
　When the thickness of the coating material is too thin, the coating material between the molten iron and the steel sheet surface effect is reduced to prevent the welding of the steel sheet 1 interposed, V2 / V1 is not reduced sufficiently together, they are scattered far molten iron for not to obstacle to scattering of molten iron, the width W 1 , the distance L s becomes excessively large. If the thickness of the coating material is too thick, it becomes difficult to melt the iron rides on the oil film, together with the height h of the convex portion 7 is deposited only in the immediate vicinity of the groove 5 becomes high, the desired V2 / V1 can not be obtained. Therefore, the thickness of the coating material is preferably set to greater than 0 ~ 50 [mu] m, more preferably between 0.01 ~ 25 [mu] m, further preferably 0.1 ~ 1 [mu] m.
[0119]
[Other For coating materials]
　boiling point of the coating material is preferably 100 ° C. or higher. If the boiling point is too low, the effect of instantaneously present invention substances a groove surrounding the high temperature will evaporate during the laser irradiation is lost. Without completely evaporated, becomes small thickness of the coating material, the effect of hold back coating material around the groove is reduced, the distance L s , or projection width W is excessively large, since the film is too thin , can not be suppressed welded to base steel molten iron rides on the coating film can not be obtained the desired V2 / V1. Boiling point is more preferably at 130 ° C. or higher, further preferably 0.99 ° C. or higher. For mixing materials, it is preferable to control the boiling point of the solvent.
[0120]
　The above embodiments are all merely illustrate concrete examples of implementing the present invention, in which technical scope of the present invention should not be limitedly interpreted. That is, the present invention is its technical idea or without departing from the essential characteristics thereof, can be implemented in various forms.
Example
[0121]
　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 not limited to this single example of conditions. 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.
[0122]
(Basic condition)
　production conditions of the grain-oriented electrical steel sheet to be used are as follows.
　By mass%, Si: 3.0%, C : 0.08%, acid-soluble Al: 0.05%, N: 0.01 %, Mn: 0.12%, Cr: 0.05%, Cu: 0.04%, P: 0.01%, Sn: 0.02%, Sb: 0.01%, Ni: 0.005%, S: 0.007%, Se: 0.001%, containing the hot rolling was performed on the slab having a chemical composition the balance being Fe and impurities, to obtain a hot rolled steel plate having a thickness of 2.3 mm.
[0123]
　Subsequently, to the above hot-rolled steel sheet, carrying out annealing for 1 minute at 1000 ° C.. Thereafter, pickling, cold rolling was performed to obtain a cold rolled steel plate having a thickness of 0.23 mm.
[0124]
　Subsequently, with respect to cold-rolled steel sheet, performing decarburization annealing for 2 minutes at 800 ° C., applying an annealing separating agent containing magnesia (MgO) as the main component on the surface. Performing a known nitriding annealing necessary.
[0125]
　Then, carrying out the final annealing treatment of 1200 ° C. 20 hours. As a result, steel sheet crystal orientation is controlled so that the crystal grains of the easy magnetization axis and the rolling direction coincides (steel sheet glass coating film is formed on the surface) is obtained.
[0126]
　The above steel sheet, an insulating coating solution containing colloidal silica and phosphate is coated, conduct heat treatment for 1 minute at 850 ° C., and finally, the grooves and protrusions are formed, further the glass coating film and insulating the surface obtaining grain oriented electrical steel sheet with a coating.
[0127]
　The formation in the course of the process, performed coated and laser irradiation of a specific substance on the surface of the steel sheet, a plurality of grooves extending in a direction perpendicular to the rolling direction (and projections), at predetermined intervals along the rolling direction to. Irradiation conditions of the laser, the laser output: 200 W, focused spot size (86% diameter) in the rolling direction of the laser: 100 [mu] m, the focusing spot diameter in the sheet width direction of the laser (86% diameter): 4000 .mu.m, the laser scanning speed: 16m / s, laser scanning pitch: a 4mm.
[0128]
　The present invention effectively, because not due to the characteristics or laser irradiation conditions of the steel sheet, described above, except for the control of the application substance before the laser irradiation, is fixed in the manufacturing conditions of a general-oriented electrical steel. Is the grain-oriented electrical steel sheet finally obtained, except for the shape of the projection that varies depending on the coating condition of a specific substance of the steel sheet surface during the laser irradiation, mainly, Si: ordinary containing 3.0% is a grain-oriented electrical steel sheet. For coating conditions and implementation timing, including laser irradiation of a specific substance which is a point of the present invention will be described in the experimental examples.
[0129]
　The groove depth of the evaluation to the steel sheet is 25 ~ 30 [mu] m or less, the width of the groove is 30 ~ 40 [mu] m, a range and a known range of fluctuations in the shape of the groove in the case where the conditions of the laser irradiation is constant, special is not.
[0130]
　Magnetic properties of these grain-oriented electrical steel sheet, rust resistance, insulating properties, and measuring the characteristics when the wound core. Further, peeling the coating of these oriented electrical steel sheet, the surface shape of the base steel is identified by a particular method described in the above embodiment. Three-dimensional roughness measurement and surface roughness parameters (Ra, RSm) the measurement of the laser type surface roughness measuring device (manufactured by Keyence Corporation of VK-9700) is used. Measurements of projections is the average of the measured values ​​of both sides of the protrusions of the groove.
[0131]
　Rust resistance is a test piece of 30mm square from each oriented electrical steel sheet was taken, the test piece, the test piece is subjected to a temperature of 50 ° C. and a humidity of 91% and allowed to stand for 1 week, the test piece in its longitudinal based on the weight change is evaluated by the mass increase rate of the following formula. Since the weight of the rust test strip is increased, it can be determined that good rust resistance as having less weight increase.
　　Mass increase rate of the left front and rear (%) = 100 × (after standing - before standing) / before standing)
[0132]
　Insulating property is evaluated by an interlayer current measured by the method described in JIS C 2550-4.
[0133]
　Magnetic properties (magnetic flux density B 8 , iron loss W 17/50 ) evaluates the veneers W60mm × L300mm according H coil method described in JIS C 2556.
[0134]
　As characteristics when the wound iron core, evaluate the building factor (BF) and noise.
[0135]
　In the measurement of the building factor, each oriented electrical steel sheets are stacked to produce a wound core 20 having the dimensions (mm) shown in FIGS. 10A and 10B. Wound core 20 is tightened by the band 21. Then, the wound core 20, a measurement using the excitation current method described in JIS C 2550-1, performed at a frequency 50 Hz, magnetic flux density 1.7T conditions, iron loss W of the wound iron core A to measure . Further, a sample of width 100 mm × length 500mm comprising only flat portion oriented electrical steel sheet used in wound cores were taken, with respect to this sample, the electromagnetic steel sheets single with H coil method described in JIS C 2556 the measurement by the plate magnetic property test, carried out at a frequency 50 Hz, magnetic flux density 1.7T conditions, iron loss value W of the base steel sheet veneer B is measured. The iron loss value W A of the iron loss value W B obtains the building factor (BF) divided by the. As BF is smaller in the present invention can be evaluated with less adverse effects when using steel sheet as wound cores.
[0136]
　In the evaluation of the noise, to prepare the above wound core, and excitation, to implement the noise measurement. In an anechoic chamber of the noise measurement background noise 16DBA, the noise level meter was installed from core surface at the position of 0.3 m, performed using A characteristic as audibility correction. The frequency in the excitation 50 Hz, the magnetic flux density 1.7 T.
[0137]
(First experimental example)
　steel sheet of the first experimental example of which is manufactured in a process comprising nitriding annealing. It is shown in detail in Table 1 to Table 3.
[0138]
[Table 1]

[0139]
[Table 2]

[0140]
[table 3]

[0141]
　Temperature of the coating material, as constant coating thickness, is an example of a case of applying a coating material different viscosities. Test No. 1-1 ~ No. Coating and laser irradiation of the coating material was carried out between between the rolling step S04 and decarburization annealing step S05 1-16 in cold. Test No. 1-17 In between the decarburization annealing step S05 the annealing separator application step S06, after coating an annealing separating agent in step S06, dried and further coated material as the die roll (Daido Chemical Industry Co., Ltd.) on which was coated in was performed laser irradiation. Test No. 1-18 between the annealing step S07 finish the annealing separator application step S06 in the laser irradiation was performed with an annealing separator agent applied in step S06 as a coating material. Test No. Between the annealing step S07 finish the annealing separator application step S06 at 1-19, after coating an annealing separating agent in step S06, dried, and carried out the laser irradiation on that further coated die roll as a coating material. Test No. In after laser irradiation 1-19 it was carried out while step S07 die rolls is attached. Test No. 1-20 and No. It was performed with a laser irradiation between the 1-21 and recrystallization annealing step S07 of the insulating film forming step S08. Test No. After the laser irradiation was carried out as a specific substance an insulating coating solution to be applied in the 1-22 in the insulating film forming step S08, was performed baking of the insulating coating. Test No. After the insulating film forming step S08 in 1-23 was performed with a laser irradiation from above the coating. Test No. It has been processed to the formation of the no insulating coating that 1-24 to form a groove in.
[0142]
　Test No. 1-2 ~ No. In 1-15, after removal at once electrolytic degreasing rolling oil of the steel sheet surface after cold rolling was applied a predetermined coating material with a predetermined condition. The die roll SZ-48H, are used as the rolling oil in cold rolling before coating, Test No. In 1-1, rolling oil on the surface immediately after rolling has laser irradiation remains attached. Test No. 1-2 ~ No. 1-15 once degreased rolling oil in after cold rolling step S04, then re-applying the coating material. Test No. Daphne roll oil was used, for example, 1-4, Daphne high-tensile oil, Daphne Marg plus and Daphne oil coat is made of Idemitsu Kosan Co., Ltd.
[0143]
　It was confirmed to improve the control and the characteristics of the shape of the steel sheet surface by the coating material. Do not apply the coating material test No. 1-16 and No. Not preferable to control the projection at 1-20, characteristics are deteriorated. Test No. 1-23 In the coating material is not applied, but the molten iron caused by grooving for adhering on the film, projection welded to the steel plate was hardly formed. However, because the value of V2 / V1 was too small, the effect of improving the adhesion of the insulation coating by the protrusions can not be sufficiently obtained, part of the insulating film is peeled off, rust resistance and the insulating property deteriorate. 11, test No. It shows a cross-sectional view of a steel plate 51 of 1-23. Further, in the invention example was carried out laser irradiation step S99 before the decarburization annealing step S05, since at least moderate secondary recrystallization in finish annealing occurs, the crystal orientation and the crystal grain size is controlled, including the projections, magnetic characteristics was also good. Test No. In 1-24, in order not to form a groove, it could not sufficiently reduce iron loss.
[0144]
(Second experimental example)
　steel sheet of the second experimental example is intended to produce a process that does not include a nitride annealing. It is shown in detail in Table 4 to Table 6.
[0145]
[Table 4]

[0146]
[table 5]

[0147]
[Table 6]

[0148]
　Test No. 2-1 ~ No. Coating and laser irradiation of the coating material was carried out between between the rolling step S04 and decarburization annealing step S05 2-16 in cold. The coating material and the coating thickness is constant, an example of changing the viscosity at a concentration and temperature in the coated state. All the coating material is a die roll SZ-48H (manufactured by Daido Chemical Industry Co., Ltd.), was evaluated in the case of the still rolling, the case to be re-applied after degreasing.
[0149]
　Change inventions effect due to change in viscosity can be confirmed, it is possible to ensure that there is particularly preferred range of the viscosity, even when used as a coating material while rolling rolling oil, the same effect as when re-coating is obtained is it can be seen.
[0150]
(Third Experiment)
　steel of a third experimental example is intended to produce a process comprising nitriding annealing. It is shown in detail in Tables 7 to 9.
[0151]
[Table 7]

[0152]
[Table 8]

[0153]
[Table 9]

[0154]
　Test No. 3-1 ~ No. Coating and laser irradiation of the coating material was carried out between between the rolling step S04 and decarburization annealing step S05 3-16 in cold. The coating material and viscosity is constant, is an example to confirm the effect of coating thickness. All the coating material is a die roll SZ-48H (manufactured by Daido Chemical Industry Co., Ltd.), was evaluated in the case of the still rolling, the case to be re-applied after degreasing.
[0155]
　Can change confirmation invention effects associated with changes in coating thickness, it can be confirmed that there is a particularly preferred range for the coating thickness. Coating thickness is a tendency that can reduce the protrusion when thin, but can not be sufficiently suppressed scattering of molten iron, the projection is to be formed at a position away from the groove. If on the other hand too thick can not molten iron rides on the film, with V2 / V1 is deteriorated, it is deposited to concentrate very close to the groove. In this state, variation (Ra, RSm) of the projection form is increased locally generated secondary recrystallization hardly causes projections, it is lowered slightly magnetic properties.
Industrial Applicability
[0156]
　The present invention is, for example, can be utilized in the manufacturing industry and use industry-oriented electrical steel sheet for an iron core of the transformer.

WE CLAIM

[Requested item 1]
　Extending direction intersects the rolling direction, comprising a steel sheet and the depth direction has a thickness direction and parallel grooves are formed steel sheet surface,
　connected to parallel to the grooves on both sides of the groove in the surface of the steel sheet molten coagulation is present and
　the height of maximum frequency in the height distribution of the height data of the measurement of the steel sheet surface within a particular area at regular intervals and the virtual plane including the groove, recessed from the imaginary plane the void volume of the recess and V1, wherein, when the volume of the convex portion protrudes from the virtual plane and the V2, the value of V2 / V1 is less than 0.10 ultra 0.80,
　a plurality of projections in the specific region There are formed, among the plurality of protrusions, the width of the closest projection in the groove is greater than the width of the other protrusions,
　the highest region average height of the extending direction in the height distribution when viewed in the groove longitudinal cross section including an extending direction and a thickness direction,
　The average roughness Ra of the roughness curve that forms the surface of the region is a 0.30 ~ 2.00 .mu.m,
　the average length RSm of a roughness curve element which forms the surface of the region, that it is 10 ~ 150 [mu] m oriented electrical steel sheet characterized.
[Requested item 2]
　Oriented electrical steel sheet according to claim 1 height to be 0.02% th in height data of said, characterized in that 1 an ultra ~ 10 [mu] m.
[Requested item 3]
　The steel sheet surface shape around the groove, when viewed in Mizonobe lengthwise direction perpendicular groove widthwise cross section,
　of the convex portion, the end portion T of the closest projection in the groove 1s and the end m of the groove distance L s oriented electrical steel sheet according to claim 1 or 2, characterized in that it is a 0 super ~ 40 [mu] m.
[Requested item 4]
　Wherein the plurality of among the projections, the width W of the closest projections on the groove 1 is oriented electrical steel sheet according to any one of claims 1 to 3, wherein the at 40μm or less.
[Requested item 5]
　Of the plurality of protrusions, the width of the closest projections on the groove W 1 , the n-th (n is an integer of 2 or more) the width of the protrusion closer to W n when expressed as, W n / W 1 of oriented electrical steel sheet according to any one of claims 1 to 4, characterized in that the value is less than 0.20 ultra 1.00.
[Requested item 6]
　Direction according to any one of claims 1 to 5, characterized in that the number of crystal grains present in the bottom of the highest elevation in a cross section perpendicular to the Mizonobe extension direction is not more than 10.0 in the average sex electromagnetic steel sheet.
[Requested item 7]
　The crystal orientation of the metal structure of protrusions of the highest region average height of the extending direction in the height distribution, billing, characterized in that the {100} <001> orientation area ratio of 65% or more oriented electrical steel sheet according to any one of claim 1 to 6.
[Requested item 8]
　On the steel sheet surface including the surface of the protrusion and the groove surface, oriented electrical steel sheet according to any one of claims 1 to 7, characterized in that it comprises a glass coating film.