JP4916919B2 - Method and apparatus for observing surface properties of magnetic band - Google Patents

Description

  The present invention relates to a method and apparatus for observing the surface properties of a magnetized magnetic band.

  It is important to control the quality by observing the surface properties of the magnetic strip. Therefore, many methods for observing the surface properties including the surface defects of the magnetic band have been proposed (for example, see Patent Documents 1 to 3).

  Patent Document 1 discloses an observation method based on the Bitter method in which a colloidal solution in which ferromagnetic fine particles are suspended is dropped on the surface of a magnetic band thin film and a domain wall image formed by aggregation of the ferromagnetic fine particles is observed. It is disclosed. Patent Document 2 discloses a method of observing the surface of a metal ribbon with a scanning electron microscope. Patent Document 3 discloses a method of observing a surface by scanning the surface with a Hall element while applying a magnetic field to a magnetic material.

  However, any of the above methods has a very small observation target area, and it is difficult to put it to practical use in a magnetic band production line that requires quick observation of the surface properties of a wide area.

  As a practical technique, several methods for detecting surface defects by observing the magnetization form on the surface of a magnetic material have been proposed (see Patent Documents 4 and 5).

  In Patent Document 4, a magnetic tape is attached to the surface of an object to be measured (ferritic steel material) via a resin layer and magnetized, and a magnetization pattern recorded on the magnetic tape is observed with an optical microscope. A nondestructive inspection method for detecting and evaluating defects is disclosed.

  In Patent Document 5, a colloidal liquid in which ferromagnetic fine particles are dispersed is applied to the surface of an object to be measured (ferritic steel material), magnetized, dried, and sprayed with a solution in which a replica film material is dissolved. A nondestructive inspection method is disclosed in which a film layer is formed by drying and solidification, and after peeling, a defect is detected and evaluated by observing the magnetization pattern of the film layer with an optical microscope.

  However, all nondestructive inspection methods are put to practical use in production lines where it takes time to form and peel magnetic tapes and film layers, and the subsequent observation, and it is necessary to quickly observe the magnetization pattern of the wide surface of the magnetic band. It is difficult to do. Moreover, the used magnetic tape or film layer cannot be reused, and the above method is expensive.

  Also, when a film is present on the surface of the magnetic band, the above-mentioned various methods cannot be applied unless the film is peeled off, but equipment is required for removing the film, and it takes time and effort. The present applicant has proposed an observation apparatus capable of observing the surface properties in a nondestructive manner without peeling off the magnetic band film (see Patent Document 6). It has been found that surface properties on a wide area surface may not be observed with a clear image.

  As described above, in the production line of the magnetic band, for the purpose of quality control, development of a technique for quickly observing a surface property on a wide area surface of a magnetic material to be observed with a clear image is required.

Japanese Patent Application Laid-Open No. 06-051042 Japanese Patent Laid-Open No. 11-014724 Japanese Patent Laid-Open No. 11-231031 Japanese Patent Laid-Open No. 08-160007 Japanese Patent Laid-Open No. 08-160008 Japanese Patent Application No. 2005-258606

  In view of the above-mentioned demand, the present invention solves the problem that surface properties on a wide area surface of a magnetic band to be observed cannot be observed quickly, and a film that obstructs observation exists on the surface of the magnetic band. However, it is an object of the present invention to provide an observation method and an observation apparatus capable of observing the surface properties of the magnetic band on a wide area surface without removing the film.

  The present inventor has intensively studied a method for displaying the surface texture with a clear image on the surface of the magnetic band to be observed.

  The present inventor said, “When a strong magnetic field of the same polarity is generated from the back surface of the magnetic band to be observed and the magnetic flux in the magnetic band is pushed up to the surface by utilizing the repulsive action of the magnetic field, The amount of leakage increased, and by detecting this amount of leakage, it was possible to display an image of the entire surface of the surface of a wide area.

  As a result, when a high permeability plate is inserted between the magnetic band to be observed and the magnetizer that magnetizes the magnetic band, and the magnetic band and the high permeability plate are magnetized integrally, the surface of the magnetic band on the wide surface It was found that the property can be displayed with a clear image.

  This invention was made | formed based on the said knowledge, and the summary is as follows.

(1) In the observation method for observing the surface properties of the magnetic band,
(A) A high permeability plate having a plate width W ₂ not exceeding the width W ₁ of the magnetic band to be observed is placed on the magnetic pole, and the high permeability plate and the magnetic band are integrally rolled in the rolling direction of the magnetic body. magnetized to,
(B) A method for observing the surface property of a magnetic band, wherein magnetic flux on the surface of the magnetic band is detected and the surface property is displayed as an image.

(2) The ratio W ₂ / W ₁ of the width W ₂ of the high magnetic permeability plate and the width W ₁ of the magnetic band is 0.9 or less, and the magnetic band according to (1) Surface texture observation method.

  (3) The method for observing the surface property of a magnetic band according to (1) or (2), wherein the high permeability plate is formed by arranging a plurality of high permeability plates along a magnetic pole.

  (4) The method for observing the surface property of a magnetic band according to any one of (1) to (3), wherein the high permeability plate is formed by laminating a plurality of high permeability plates.

( 5 ) The high permeability plate and the magnetic band are integrally magnetized so that the easy magnetization axis direction of the high permeability plate coincides with the rolling direction of the magnetic band, and (1) to ( 4 ) The method for observing the surface property of the magnetic band according to any one of the above.

( 6 ) The surface property observation method for a magnetic band according to any one of (1) to ( 5 ), wherein the surface property is displayed as an image through a film.

( 7 ) The surface property observation method for a magnetic band according to any one of (1) to ( 6 ), wherein the surface property is a surface strain or a surface defect.

( 8 ) An observation device for observing the surface properties of a magnetic band,
(A) A high-permeability plate having a plate width W ₂ not exceeding the width W ₁ of the magnetic band to be observed is placed on the magnetic pole, and the high-permeability plate and the magnetic band are integrated in the rolling direction of the magnetic body. A magnetizer to magnetize; and
(B) An apparatus for observing the surface property of a magnetic band, comprising a display for detecting the magnetic flux on the surface of the magnetic band and displaying an image of the surface property.

(9) and the high-permeability width W ₂ of the plate, the ratio W ₂ / W ₁ of the width W ₁ of the magnetic strip of the magnetic strip according to (8), characterized in that 0.9 or less Surface texture observation device.

( 10 ) The apparatus for observing the surface property of a magnetic band according to ( 8 ) or ( 9 ), wherein the high permeability plate is configured by arranging a plurality of high permeability plates along a magnetic pole. .

( 11 ) The surface property observation apparatus for a magnetic band according to any one of ( 8 ) to ( 10 ), wherein the high permeability plate is a laminate of a plurality of high permeability plates.

( 12 ) The surface property observation of the magnetic band according to any one of ( 8 ) to ( 11 ), wherein the high permeability plate and the magnetic band are magnetized in the rolling direction of the magnetic band by the magnetizer. apparatus.

(13) wherein the magnetization easy axis of the high magnetic permeability plate, to match the rolling direction of the magnetic strip, with the magnetizer, the (12, characterized in that the magnetized integrally high permeability plate and the magnetic strip ) Is an apparatus for observing the surface properties of a magnetic band.

( 14 ) The surface property observation apparatus for a magnetic band according to any one of ( 8 ) to ( 13 ), wherein the display device displays an image of the surface property through a film.

( 15 ) The surface property observation apparatus for a magnetic band according to any one of ( 8 ) to ( 14 ), wherein the surface property is a surface strain or a surface defect.

  According to the present invention, even if a film that obstructs observation is present on the surface of the magnetic band, it is possible to observe the surface properties on a wide surface of the magnetic band with a clear image without removing the film. it can. As a result, a large amount of equipment cost and equipment maintenance cost are not required in the magnetic band production line, and surface quality control of the magnetic band can be determined safely and in a short time.

  The present inventor first gives several wrinkles (hereinafter referred to as “surface wrinkles”) with a scribing needle over the entire surface of the flat magnetic band, and the magnetic field is perpendicular to the plane of the magnetic band (a). Direction, (b) horizontal C direction in the plane (direction perpendicular to the rolling direction), and (c) horizontal L direction (rolling direction), and surface properties on the surface of the magnetic band were observed.

  Magnetization of the magnetic band is performed using a coil, and the surface property is determined using an observation device (see Patent Document 6) in which a magnetic fluid layer mixed with magnetic powder is sandwiched between a transparent surface layer and a back sheet layer. Imaged and observed.

  As a result, when the magnetic field is applied in the vertical direction and in the horizontal C direction (in the case of (a) and (b)), it is possible to observe unclear surface properties over the entire surface of the magnetic band. When a magnetic field is applied in the horizontal L direction (in the case of (c)), the surface defects are not visible near the center and near the center of the magnetic band, but the surface defects are clear near the edge. It was found that can be observed.

  The present inventor paid attention to the phenomenon that the surface defects appear differently near the edge and the center of the magnetic body. (I) Near the edge of the magnetic band, the edge penetrates the magnetic body obliquely from the surface due to the edge effect. (Ii) In the vicinity of the center of the magnetic band, the magnetic flux that has penetrated the magnetic band does not leak to the surface, or even if it leaks, the amount is less than the end (insufficient) I thought that there was a cause.

  According to this idea, in order to observe a surface defect with a clear image over the entire surface of the magnetic band to be observed, it is necessary to leak the magnetic flux outside the surface over the entire surface of the magnetic band. The present inventor examined this technique.

  If the inventor generates a strong magnetic field of the same polarity on the back surface of the magnetic band and uses the repulsive action of the magnetic field to push up the magnetic flux in the magnetic band, the amount of magnetic flux leaking from the surface of the magnetic band increases. Thus, it was concluded that one surface property could be observed with a clear image over the entire surface, and a high permeability plate was placed on the magnetic pole of the magnetizer.

  That is, the present invention is a magnetizer in which a high permeability plate is placed on a magnetic pole, magnetizes the high permeability plate and the magnetic band to be observed integrally, and the magnetic field of the high permeability plate The magnetic flux in the belt is pushed up.

  Here, FIG. 1 schematically shows an observation mode using a conventional magnetizer. FIG. 1A shows a planar positional relationship between the magnetic pole 2, the magnetic strip 1, and the display 3, and FIG. 1B shows their lateral positional relationship.

  FIG. 2 schematically shows an observation mode using the magnetizer of the present invention. FIG. 2A shows the planar positional relationship of the magnetic pole 2, the high magnetic permeability plate 4, the magnetic band 1, and the display 3, and FIG. 2B shows the lateral positional relationship thereof.

  Conventionally, as shown in FIG. 1B, a magnetic band 1 to be observed is placed on a magnetizer having a magnetic pole 2, and a display 3 for imaging and displaying the surface properties on the magnetic band 1 is displayed thereon. The surface properties on the surface of the magnetic band 1 are imaged. However, one surface property could not be observed with a clear image over the entire surface of the magnetic band 1. The reason for this will be described later.

  On the other hand, in the present invention, as shown in FIG. 2, the magnetic band 1 to be observed is magnetized by a magnetizer configured by placing a high permeability plate 4 on the magnetic pole 2, and on the surface thereof. The surface property is displayed on the display 3 as an image.

  When the magnetic band 1 to be observed and the high permeability plate 4 are integrally magnetized, the magnetic field of the high permeability plate 4 pushes up the magnetic flux in the magnetic band 1 and the amount of magnetic flux leaking from the surface of the magnetic band 1 increases. . By detecting the amount of magnetic flux leaking, the surface properties of the entire surface of the magnetic band 1 can be displayed as a clear image on the display 3.

  The reason for this will be described.

  FIG. 3 schematically shows an aspect of the magnetic flux when the magnetic band is magnetized. FIG. 3A shows the magnetic flux when the magnetic band 1 is magnetized by the conventional magnetizer shown in FIG. 1, and FIG. 3B shows the magnetic band 1 in the magnetizer of the present invention shown in FIG. The mode of the magnetic flux when magnetizing is shown.

  As shown in FIG. 3A, when magnetized by a conventional magnetizer, the magnetic flux 6 stays in the vicinity of the center of the magnetic band, so that the magnetic flux 6 does not leak outside at the strain or defect 5 Or even if it leaks, the amount is small, and as a result, the surface property cannot be imaged and displayed on the display.

  On the other hand, in the vicinity of the end of the magnetic band 1, magnetic flux that has entered the magnetic body 1 obliquely from the vicinity of the surface leaks to the surface due to the edge effect, and the magnetic flux 6 leaks outside at the strain or defect 5 existing on the surface. By detecting this leakage magnetic flux, the surface texture of the surface can be imaged.

  Thus, when magnetized by a conventional magnetizer that does not use the high permeability plate 4, the strain or defect 5 existing on the surface of the magnetic band 1 cannot be observed in the vicinity of the center and the vicinity of the end. As a result, a surface property in the entire surface of the magnetic band 1 to be observed cannot be displayed as a clear image.

  On the other hand, as shown in FIG. 3B, when the high permeability plate 4 is placed under the magnetic band 1 to be observed and the magnetic band 1 and the high permeability plate 4 are magnetized integrally, the high permeability plate The magnetic flux 6 in the vicinity of the center is pushed up by the magnetic flux 6 of 4 and the magnetic flux 6 leaks outside at the strain or defect 5 existing on the surface. By detecting this leakage magnetic flux, The surface properties can be imaged and displayed.

  Therefore, as shown in FIG. 2B, when the high permeability plate 4 is placed on the magnetic pole 2 and the high permeability plate 4 and the magnetic band 1 to be observed are magnetized integrally, the result shown in FIG. As shown, the magnetic flux 8 of the high permeability plate 4 leaks at the strain or defect 5 existing on the surface even in the vicinity of the center of the magnetic band 1 to be observed. Thus, the surface properties of the entire surface of the magnetic band 1 to be observed can be displayed as a clear image.

  The magnetizer of the present invention shown in FIG. 2 will be further described.

  As the high permeability plate 4 placed on the magnetic pole, a high permeability plate with good permeability is used to push up the magnetic flux in the magnetic band 1 to be observed. Preferably, a magnetic plate having a permeability equal to or higher than the permeability of the magnetic substance to be observed is used.

  As the high permeability plate, an iron plate, a silicon steel plate, a directional silicon steel plate, ferrite, permalloy, amorphous, or the like can be used, but it is necessary to select a high permeability plate according to the magnetic band to be observed.

The length L ₂ of the high permeability plate 4 in the direction perpendicular to the magnetic field application direction may exceed the length L ₁ of the magnetic band 1 (see FIG. 2A), but the magnetic field application of the high permeability plate 4 The length W ₂ (width) in the direction shall not exceed the width W ₁ of the magnetic band 1.

However, if W ₂ / W ₁ ≈1, the magnetic permeability lifting action of the high permeability plate 4 may be weak, so W ₂ / W ₁ is preferably 0.90 or less, and more preferably 0.65 or less. .

For example, when W ₁ is 80 mm, W ₂ ≦ 70 mm (<80 × 0.90) is preferable, and W ₂ ≦ 50 mm (<80 × 0.65) is more preferable.

The higher the magnetic permeability plate, the smaller the width W ₂ (W ₂ <W ₁ ), the smaller the magnetic circuit resistance, the stronger the internal magnetic field is obtained, and the curvature of the magnetic field (lines of magnetic force) is higher. Since it becomes large (the center becomes convex), it becomes easy to push up the magnetic flux of the magnetic band to be observed from the back surface.

The lower limit of the width W ₂ of the high permeability plate is not particularly limited, but if it is too narrow, it becomes difficult to configure the magnetizer, and it becomes difficult to observe the entire surface of the magnetic band. appropriately set according to the width W ₁ but, W _1/4 ≦ W ₂ is preferred.

The width W ₂ of the high magnetic permeability plate is preferably 10 mm ≦ W ₂ ≦ 70 mm, and more preferably 20 mm ≦ W ₂ ≦ 50 mm. When the width W ₂ of the high permeability plate exceeds 70 mm, the push-up action of the magnetic field near the center is weakened, and the sharpness of the image near the center is lowered. It becomes difficult to do.

The thickness t ₂ of the high permeability plate 4 is not particularly limited in relation to the thickness t ₁ of the magnetic band 1 to be observed. Any thickness that can hold a magnetic field with sufficient strength to push up the magnetic flux of the magnetic band to be observed is acceptable. As shown in FIG. 4, a plurality of high magnetic permeability plates may be laminated (in the figure, high magnetic permeability plates 4a, 4b, 4c are laminated) and integrated for use. As the number of stacked layers increases, the distance between the magnetic pole 2 and the magnetic band 1 increases, so the internal magnetic field of the magnetic band 1 becomes weaker and the magnetic flux in the magnetic band 1 is easily pushed up from the back surface.

However, if too thick a stack thickness t ₃ of the high magnetic permeability plate, strong magnetizing force to magnetization integrally magnetic strip to be observed and the laminated high permeability plate is required, forced to increase the magnetizer The thickness t ₂ or the laminate thickness t ₃ of one high permeability plate is preferably 0.3 mm or greater and 1.6 mm or less, and more preferably 0.6 mm or greater and 1.2 mm or less. .

In the case where a plurality of high magnetic permeability plates are laminated, W ₂ / W ₁ is preferably 0.90 or less, and more preferably 0.65 or less.

  By appropriately adopting the above aspect, the amount of magnetic flux leaking from the surface of the magnetic band increases, and the surface properties can be observed with a clear image over the entire surface of the magnetic band.

  Further, when a material having an easy magnetization axis direction such as a directional silicon steel plate is used as the high permeability plate 4 by laminating one or a plurality of materials, the easy magnetization axis direction of the high permeability plate is set as the magnetic field application direction. When matched, the effect of raising the magnetic flux by the magnetic field of the high permeability plate can be obtained more remarkably, and the surface properties can be observed with a clearer image over the entire surface of the magnetic band.

  As shown in FIG. 5, the high permeability plate 4 may be configured by arranging the high permeability plates 4 a, 4 b, 4 c at appropriate intervals or in contact with each other. This method is effective when it is difficult to obtain a single high-permeability plate having good magnetic permeability, or when it is difficult to obtain a single high-permeability plate having a uniform magnetization axis.

  Next, examples of the present invention will be described. The conditions of the examples are one example of conditions adopted for confirming the feasibility and effects of the present invention, and the present invention is limited to this one example of conditions. Is not to be done. The present invention can adopt various conditions as long as the object of the present invention is achieved without departing from the gist of the present invention.

Example 1
In the magnetization mode shown in FIG. 2 or FIG. 4, several surface defects are generated on the entire surface of the iron plate of W ₁ : 80 mm × L ₁ : 200 mm × t ₁ : 0.23 mm with a marking needle. Was observed.

As a high permeability plate, (a) W ₂ : 70 mm × L ₂ : 250 mm × t ₂ : 0.23 mm directional silicon steel plate, or (b) W ₂ : 50 mm × L ₂ : 250 mm × t ₂ : 0 A magnetizer was constructed by placing 1-3 directional silicon steel sheets of 23 mm on ferrite magnets.

  On the magnetic band, a display of width W: 80 mm × length L: 200 mm × thickness: 6 mm is placed, the magnetizer is magnetized with a current of 10 A, and an image of the surface defect displayed on the display is observed. It was evaluated whether surface defects could be observed over the entire image.

  Specifically, A: A surface wrinkle can be observed with a clear image over the entire image, B: A part of the surface wrinkle can be observed with a clear image, and C: A surface wrinkle can be observed with the entire image. Was able to observe surface wrinkles over the entire image, and D: the surface wrinkles could not be observed over the entire image. The evaluation results are shown in Table 1.

  FIG. 6 shows an example (a) of an image of evaluation A and an example (b) of an image of evaluation B when the surface flaw 7 of the iron plate is observed. In the figure, the solid line indicates clear surface defect observation, and the dotted line indicates unclear surface defect observation.

(Example 2)
In the magnetization mode shown in FIG. 2 or 4, several surface defects are generated on the entire surface of the iron plate of W ₁ : 80 mm × L ₁ : 200 mm × t ₁ : 0.23 mm with a scribing needle, Then, a plating film or the like was simulated to cover a Teflon (registered trademark) sheet having a thickness of about 50 μm, and surface defects were observed from above.

As a high permeability plate, (a) W ₂ : 70 mm × L ₂ : 250 mm × t ₂ : 0.23 mm directional silicon steel plate, or (b) W ₂ : 50 mm × L ₂ : 250 mm × t ₂ : 0 A magnetizer was constructed by placing 1-3 directional silicon steel sheets of 23 mm on ferrite magnets.

  On the magnetic band, put a display of width W: 80 mm × length L: 200 mm × thickness: 6 mm, magnetize the magnetizer with a current of 10 A, observe the image of the surface defect displayed on the display, It was evaluated whether surface defects could be observed over the entire image.

  Specifically, A: A surface wrinkle can be observed with a clear image over the entire image, B: A part of the surface wrinkle can be observed with a clear image, and C: A surface wrinkle can be observed with the entire image. Was able to observe surface wrinkles over the entire image, and D: the surface wrinkles could not be observed over the entire image. The evaluation results are also shown in Table 1.

  From the results of Example 2, it can be understood that surface flaws can be observed without removing the film even when a film that obstructs observation is present.

  The magnetic band is not limited to the iron plate, and can be applied to a kind of material similar to the high permeability plate. In addition, regarding the silicon steel plate, the crystal structure and the like can be observed from above the coating.

(Comparative example)
As a comparative example, an iron plate of W ₁ : 80 mm × L ₁ : 200 mm × t ₁ : 0.23 mm was magnetized with a conventional magnetizer (see FIG. 1), and surface defects were observed in the same manner as in the example. evaluated. The evaluation result was D.

  As described above, according to the present invention, even if a film that obstructs observation is present on the surface of the magnetic material, the surface properties of the entire surface of the magnetic band can be clearly displayed without removing the film. Can be displayed. As a result, a large amount of equipment cost and equipment maintenance cost are not required in the magnetic band production line, and the quality of the magnetic band can be determined safely and in a short time. Therefore, the present invention has great applicability in an industrial production line for magnetic bands.

It is a figure which shows typically the observation aspect using the conventional magnetizer. (A) shows the plane positional relationship of a magnetic pole, a magnetic strip, and a display, (b) shows those side surface positional relationships. It is a figure which shows typically the observation aspect using the magnetizer of this invention. (A) shows the plane positional relationship of a magnetic pole, a high magnetic permeability board, a magnetic strip, and a display, and (b) shows those side surface positional relationships. It is a figure which shows typically the aspect of the magnetic flux when magnetizing a magnetic strip. (A) shows the magnetic flux when the magnetic band is magnetized by the conventional magnetizer shown in FIG. 1, and (b) shows the magnetic flux when the magnetic band is magnetized by the magnetizer of the present invention shown in FIG. The aspect of is shown. It is a figure which shows the aspect which laminated | stacked multiple high magnetic permeability plates in the magnetizer of this invention. In the magnetizer of the present invention, it is a diagram showing an aspect in which three high permeability plates are arranged to form an integral high permeability plate. It is a figure which shows an example of the image of a magnetization form. (A) shows an image of evaluation A, and (b) shows an image of evaluation B.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Magnetic strip 2 Magnetic pole 3 Indicator 4, 4a, 4b, 4c High permeability board 5 Strain or defect 6 Magnetic flux 7 Surface defect

Claims (15)

In the observation method of observing the surface properties of the magnetic band,
(A) A high permeability plate having a plate width W ₂ not exceeding the width W ₁ of the magnetic band to be observed is placed on the magnetic pole, and the high permeability plate and the magnetic band are integrally rolled in the rolling direction of the magnetic body. magnetized to,
(B) A method for observing the surface property of a magnetic band, wherein magnetic flux on the surface of the magnetic band is detected and the surface property is displayed as an image. _2. The surface property observation method for a magnetic band according to claim 1, wherein a ratio W ₂ / W ₁ of a width W ₂ of the high permeability plate and a width W ₁ of the magnetic band is 0.9 or less. .   3. The method for observing the surface property of a magnetic band according to claim 1, wherein the high permeability plate is formed by arranging a plurality of high permeability plates along the magnetic poles.   The surface property observation method for a magnetic band according to any one of claims 1 to 3, wherein the high permeability plate is formed by laminating a plurality of high permeability plates. The magnetization easy axis of the high magnetic permeability plate, to match the rolling direction of the magnetic band, any one of claims 1 to 4, wherein the magnetizing integrally high permeability plate and the magnetic strip The surface property observation method of the magnetic band as described in 1. Surface texture observation method of a magnetic strip according to any one of claims 1 to 5, characterized in that the surface property, the image displayed through the coating. The surface properties, surface surface texture observation method of a magnetic strip according to any one of claims 1 to 6, characterized in that a distortion or a surface defect. An observation device for observing the surface properties of a magnetic band,
(A) A high-permeability plate having a plate width W ₂ not exceeding the width W ₁ of the magnetic band to be observed is placed on the magnetic pole, and the high-permeability plate and the magnetic band are integrated in the rolling direction of the magnetic body. A magnetizer to magnetize; and
(B) An apparatus for observing the surface property of a magnetic band, comprising a display for detecting the magnetic flux on the surface of the magnetic band and displaying an image of the surface property. The apparatus for observing the surface property of a magnetic band according to claim 8 , wherein a ratio W ₂ / W ₁ of the width W ₂ of the high permeability plate and the width W ₁ of the magnetic band is 0.9 or less. . The high magnetic permeability plate surface texture observation apparatus of the magnetic strip according to the plurality of high magnetic permeability plate to claim 8 or 9, characterized in that is constructed by arranging along the pole. The surface property observation apparatus for a magnetic band according to any one of claims 8 to 10 , wherein the high permeability plate is a laminate of a plurality of high permeability plates. The surface property observation apparatus for a magnetic band according to any one of claims 8 to 11 , wherein the high magnetic permeability plate and the magnetic band are magnetized in the rolling direction of the magnetic band by the magnetizer. The magnetization easy axis of the high magnetic permeability plate, to match the rolling direction of the magnetic strip, in magnetizer of claim 12, wherein the magnetizing integrally high permeability plate and the magnetic strip An apparatus for observing the surface properties of magnetic bands. The surface property observation device for a magnetic band according to any one of claims 8 to 13 , wherein the display device displays an image of the surface property through a film. The surface properties, surface texture observation apparatus of the magnetic strip according to any one of claims 8 to 14, which is a surface strain or surface defects.

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