JP2010240692A - Amorphous alloy ribbon - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an amorphous alloy ribbon having consistent and excellent surface characteristic in the width direction. <P>SOLUTION: The number of damages having the dimension of ≥50 μm in the direction orthogonal to the casting direction which are present in an arbitrary rectangular area in contact with a cooling roll and having the length of a long ridge of the amorphous alloy thin strip being 100 mm, and the length of a short ridge of the thin strip being 25 mm in plane, is ≤5. The iron loss (W<SB>13/50</SB>) during the excitation of 50 Hz and 1.3T at each position, and the magnetic flux density (B<SB>0.8</SB>) at the magnetic field of ≤80A/m are less degraded, and the consistent magnetic characteristic can be obtained. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an amorphous alloy ribbon manufactured by, for example, a single roll method.

  Conventionally, electromagnetic steel sheets and amorphous alloy ribbons have been used as iron core materials such as power transformers and high-frequency transformers. In particular, amorphous alloy ribbons (hereinafter sometimes referred to as ribbons) are attracting attention as iron core materials with less energy loss because they have lower iron loss than electromagnetic steel sheets. However, the amorphous alloy ribbon has a small saturation magnetic force and the design magnetic flux density in the transformer must be lowered. Therefore, when this amorphous alloy ribbon is used as the iron core material, it is compared with the electrical steel sheet. When a transformer is manufactured, for example, the amount of material such as an iron core (core) or copper wire is increased, and the manufacturing cost is increased.

  Such an amorphous alloy ribbon is generally produced by a single roll method in which molten metal is ejected from a rectangular orifice on the surface of a cooling roll rotating at a high speed and rapidly solidified. When producing an amorphous alloy ribbon by the single roll method, the important points are the uniformity of the plate thickness and the surface properties. The superiority or inferiority of the surface texture is not only due to the magnetic properties of the amorphous alloy ribbon on a single plate, but especially when the amorphous alloy ribbon is laminated and used like an iron core such as a power transformer. It also affects the properties of the wick. When this surface property is deteriorated, the space factor may be reduced, the iron core may be enlarged, or the magnetic characteristics may be deteriorated, resulting in an increase in iron loss and noise. Accordingly, various proposals have been made to produce amorphous alloy ribbons having excellent surface properties.

  For example, Patent Document 1 discloses an amorphous metal ribbon in which the surface roughness Rz on the non-contact side surface with respect to the cooling roll is 1.5 μm or less. Patent Document 2 discloses a soft magnetic alloy ribbon in which the air pocket width of the roll surface is 35 μm or less, the length is 150 μm or less, and the average roughness Ra is 0.5 μm or less. Further, Patent Document 3 discloses an Fe—Si—B amorphous alloy ribbon in which the area ratio occupied by the air pockets on the surface on the roll surface side is 20% or less.

  Patent Document 4 discloses Fe-Si- for power transformer iron cores, cast in an atmosphere of carbon dioxide gas of 40 vol% or more and having a center line average roughness Ra of a contact surface with a cooling roll of 0.7 μm or less. B-C wide amorphous alloy ribbons are disclosed. Furthermore, Patent Document 5 discloses a low B-containing Fe—Si—B amorphous alloy having a plate thickness of 15 to 25 μm and a surface roughness Ra of 0.8 μm.

  Patent Document 6 discloses a manufacturing method for preventing dust generated by polishing from being caught in a ribbon during casting by polishing the cooling roll at a position that does not interfere with the circumference of the casting part. Is disclosed.

JP-A-6-7902 JP 2000-328206 A JP 2000-54089 A JP-A-9-143640 JP-A-9-268354 JP 2002-321042 A JP 2008-279459 A

  However, all of the technologies that have been proposed so far have been made with a focus on the local physical properties of amorphous alloy ribbons, and have been proposed from the viewpoint of the effects of ribbon surface scratches on the properties. There was nothing that was done.

  An object of the present invention is to provide an amorphous alloy ribbon having stable and excellent surface characteristics in the width direction in view of the above-mentioned problems.

  The amorphous alloy ribbon of the present invention is cast (manufactured) in an arbitrary rectangular region having a long side length of 100 mm and a short side length of 25 mm in the plane in contact with the cooling roll. The number of scratches whose dimension in the direction perpendicular to the direction is 50 μm or more is 5 or less.

  According to the present invention, since the range of scratches that do not affect the characteristics is defined, stable magnetic characteristics can be obtained. Further, even when the slit is used, there is little variation in product characteristics depending on the use position, and the yield is improved.

In the Example of this invention, it is a figure explaining the outline | summary of the single roll method which manufactured the amorphous alloy ribbon. It is a figure which shows the relationship between the characteristic ratio of a flawed part with respect to the average value of a flawless part of an iron loss, and the number of flaws. It is a figure which shows the relationship between the characteristic ratio of a flawed part with respect to the average value of a flawless part of magnetic flux density, and the number of flaws.

  When a large number of scratches are present on the surface of the amorphous alloy ribbon, the surroundings of the scratch are partially crystallized to deteriorate brittleness and magnetic characteristics, and unevenness is generated on the ribbon surface, resulting in a decrease in the space factor. Therefore, when processing into iron cores, iron loss at the core not only deteriorates noise and other characteristics, but also causes problems such as breaking of the ribbon starting from scratches, reducing yield and work efficiency. .

  As a result of intensive studies on the influence of scratches generated on the surface of the ribbon, the present inventors have found that the width of the amorphous alloy ribbon on the surface in contact with the cooling roll (perpendicular to the casting direction of the ribbon) If the number of scratches of 50 μm or more is 5 or less in an arbitrary rectangular region having a long side length of 100 mm and a short side length of 25 mm, there is little influence on the magnetic properties, and We found that dispersion was suppressed and stable performance was obtained.

That is, as shown in FIG. 2 and FIG. 3, the number of scratches with a width of 50 μm or more correlated with the magnetic characteristics. FIG. 2 is a graph showing the relationship between the characteristic ratio of the scratched portion and the number of scratches with respect to the average value of the _scratchless portion of the iron loss (50 Hz, iron loss at 1.3 T excitation: W _13/50 ). FIG. 3 is a graph showing the relationship between the characteristic ratio of the scratched portion and the number of scratches with respect to the average value of the scratchless portion of the magnetic flux density (magnetic flux density at a magnetic field of 80 A / m: B _0.8 ). In any case, when the number of scratches is 5 or less, the deterioration of the characteristics is rapidly reduced. On the other hand, if the number of such scratches is 6 or more, the iron loss and the magnetic flux density are greatly deteriorated, and stable performance cannot be obtained.

  As a result of investigating the relationship between the properties of the ribbon and the core, the present inventors have found that when the iron loss deteriorates to 50% or more, the iron loss in the core is remarkably deteriorated and the product yield is greatly reduced. It was. In a more preferred range, the deterioration of iron loss was 40% or less. Further, for the magnetic flux density, the deterioration needs to be 20% or less due to the design, and a more preferable range is 10% or less.

  In addition, the thin band wound is likely to be broken starting from the scratch during slit processing, but if the number of scratches in the rectangular region is 5 or less, such breakage is suppressed and workability is improved. I also found something to do. Further, the space factor is improved by reducing the scratches.

  Surface scratches on the amorphous alloy ribbon are mainly generated by scratches on the surface of the cooling roll during the production of the ribbon and mixing of abrasive powder. Therefore, if the polishing powder is prevented from adhering to the surface of the cooling roll and the surface of the cooling roll is sufficiently polished, scratches on the amorphous alloy ribbon are reduced.

  Note that the dimension in the direction perpendicular to the casting direction in the scratch is defined as 50 μm or more. When the width of the scratch is less than 50 μm, the range of crystallization by the scratch is small and the influence of the magnetic characteristics is small. This is because no clear correlation is observed.

  As described above, the present invention is present in an arbitrary rectangular region having a long side length of 100 mm and a short side length of 25 mm in a plane in contact with the cooling roll, and perpendicular to the casting direction. The number of scratches with a dimension of 50 μm or more is required to be 5 or less. However, 3 or less is required to obtain more stable magnetic characteristics, and 2 or less is required to obtain more stable magnetic characteristics. Preferably there is.

  Such an effect of the present invention is remarkable when the width of the amorphous alloy ribbon is 25 mm or more.

  Furthermore, it is preferable that the surface roughness Ra (center line average roughness) on the surface in contact with the cooling roll in the amorphous alloy ribbon of the present invention is 0.3 μm ≦ Ra ≦ 1.0 μm. When the surface roughness Ra exceeds 1.0 μm, the air pocket generated on the surface in contact with the cooling roll is coarsened to form crystals in the air pocket portion, and the magnetic characteristics are deteriorated in the same manner as the characteristics are deteriorated due to scratches. Sometimes. The surface roughness should be smooth, but for thin ribbons that can be industrially mass-produced, it is about 0.3 μm. If you try to reduce the surface roughness beyond that, the cost will increase. Was 0.3 μm.

  Further, in the present invention, it is necessary that the number of scratches having a dimension perpendicular to the casting direction of 50 μm or more is 5 or less. The breakage is more likely to occur. As described above, the number of scratches having a width of less than 50 μm is not limited because the range of crystallization by scratches is small and the influence of magnetic properties is small, but when the length of the scratch in the casting direction exceeds 500 μm, The range of crystallization due to scratches may be so large that it cannot be ignored. Therefore, it is preferable that the length of the scratch | existence which exists in the surface which contacted the cooling roll in an amorphous alloy ribbon is 500 micrometers or less.

Next, examples for producing the amorphous alloy ribbon of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram for explaining the outline of a single roll method in which an amorphous alloy ribbon is cast in this embodiment.
In FIG. 1, the opening surface of the nozzle 4 is brought close to the circumferential surface of the cooling roll 5 rotating at high speed. When the stopper 3 in the tundish 1 is raised, the molten alloy 2 is jetted onto the circumferential surface of the cooling roll 5. The ejected molten alloy 2 is rapidly solidified on the surface of the cooling roll 5 to obtain an amorphous alloy ribbon 6. The amorphous alloy ribbon 6 is wound around a winding roll 7 provided close to the cooling roll 5. When a predetermined amount of the amorphous alloy ribbon 6 is wound on the winding roll 7, it is switched to a new winding roll (not shown), and the production of the amorphous alloy ribbon is continued up to a predetermined production amount. .

  Further, a polishing device 8 for polishing a portion between the discharge portion of the amorphous alloy ribbon 6 of the cooling roll 5 and the contact portion of the molten alloy 2 is provided. After the discharge of the amorphous alloy ribbon 6, there may be a residue due to a molten alloy or an abrasive or surface scratches on the cooling roll 5 on the surface of the cooling roll 5. Residues and surface scratches are removed, and the molten alloy 2 comes into contact with the clean surface of the chill roll 5.

  Using the apparatus as described above, Fe: 80.5%, Si: 6.5%, B: 12.0%, C: 1.0% are contained in atomic%, and a part of Fe is an inevitable impurity. An Fe-based molten alloy 2 made of 1 was fed into the tundish 1. Then, by pulling up the stopper 3, the molten alloy 2 is sprayed from the opening of the rectangular slit-shaped nozzle 4 of 170 mm × 0.85 mm onto the surface of the cooling roll 5 having a diameter of 1198 mm and a roll width of 250 mm. Of Fe-type amorphous alloy ribbon 6 having a thickness of 170 mm and a plate thickness of about 30 μm was produced and wound on a take-up roll 7. The peripheral speed of the cooling roll 5 was 21 m / s, and the gap was 200 μm and 300 μm. Further, the amorphous alloy ribbon 6 was manufactured while polishing the cooling roll 5 with the polishing device 8 so that the amorphous alloy ribbon 6 was not damaged.

  In this example, the polishing apparatus 8 was constituted by a resin brush roll and polishing paper, and was first polished using a brush roll and then polished using polishing paper. Such a technique related to polishing is described in Patent Document 7, for example.

  A plurality of samples are taken from arbitrary positions with respect to the casting direction of the obtained amorphous alloy ribbon, and a sample for evaluation (width 25 mm × length 100 mm) is taken from the sample, and the number of scratches and magnetism are obtained. Properties and roughness were evaluated. For comparison, a similar investigation was performed on an amorphous alloy ribbon cast under the same conditions by the above apparatus without polishing and removing the residue and surface scratches on the surface of the cooling roll.

The magnetic characteristics were compared at an iron loss of 50 Hz and 1.3 T excitation: W _13/50 and a magnetic flux density under a magnetic field of 80 A / m: B _0.8, which are important indexes in actual use. The magnetic properties were measured using a single-plate magnetometer, after annealing the collected ribbon sample at 360 ° C. for 1 hour in a nitrogen atmosphere. Table 1 shows the influence on the magnetic properties due to the presence or absence of flaws arranged based on the measurement results, and the roughness Ra of the surface in contact with the thin ribbon cooling roll at that time. In addition, the characteristic ratio of Table 1 is a characteristic ratio with respect to the average value of the scratch-free portion of the ribbon manufactured with a gap of 200 μm in both the present invention example and the comparative example.

  When the amorphous alloy ribbon manufactured in this example was observed in detail, there were almost no scratches, and there were at most two in a rectangular area of 25 mm × 100 mm. On the other hand, many scratches occurred in the comparative example.

  As shown in Table 1, in the example of the present invention, the occurrence of scratches is small, and when there is no scratch, there is almost no change in the characteristics, whereas in the comparative example, the characteristics deteriorate with increasing scratches. When the number of scratches is 6 or more, the deterioration of iron loss is 50% or more, and the deterioration of magnetic flux density is also 20% or more, which does not satisfy the standard for use in the core. I understand that. In addition, when the roughness Ra of the surface in contact with the thin belt cooling roll is 1.0 μm or less, the air pockets generated on the surface in contact with the cooling roll are not coarsened, and the magnetic characteristics are less deteriorated and better. It can be seen that the magnetic properties are excellent.

FIG. 2 shows the relationship between the characteristic ratio of the scratched portion and the number of scratches with respect to the average value of the _scratchless portion of the iron loss (50 Hz, iron loss at excitation of 1.3 T: W _13/50 ) in the comparative example as described above. FIG. FIG. 3 is a graph showing the relationship between the characteristic ratio of the scratched portion and the number of scratches with respect to the average value of the scratchless portion of the magnetic flux density (magnetic flux density at a magnetic field of 80 A / m: B _0.8 ).
As shown in FIG. 2 and FIG. 3, when comparing the characteristic ratio with respect to the number of scratches, the iron loss and magnetic flux density deterioration were small and good results were obtained at a position with few scratches. When exceeding, the iron loss is deteriorated by about 50% and the magnetic flux density is deteriorated by about 20%. From this, it is understood that the iron loss is large in the amorphous alloy ribbon including a region with many scratches, and when slitting, there is a large variation in the iron loss between the position with many scratches and the position with few scratches. . It can also be seen that the magnetic flux density varies greatly.

  On the other hand, in the amorphous alloy ribbon of this example, as shown in Table 1, since the number of scratches was small in any sample, there was no deterioration in iron loss and magnetic flux density, and the variation was small. . From this, it can be seen that there is no variation in performance even when slitting.

  As described above, according to the present embodiment, stable magnetic characteristics in the width direction can be obtained. Therefore, for example, even when used as a slit, there is little variation in characteristics of the product depending on the use position, and the yield is improved. I can say that. Further, in the process of manufacturing the iron core, the occurrence of breakage due to scratches is reduced, so that it can be said that the workability is excellent and the working efficiency is improved. In addition, since the number of scratches is small, a high space factor can be obtained by stacking thin ribbons to manufacture an iron core, so that it can be said that noise and energy loss generated by holes can be reduced.

DESCRIPTION OF SYMBOLS 1 Tundish 2 Molten metal 3 Stopper 4 Nozzle 5 Cooling roll 6 Thin strip 7 Winding roll 8 Polishing apparatus

Claims (3)

  The dimension in the direction perpendicular to the casting direction is 50 μm or more in an arbitrary rectangular region having a long side length of 100 mm and a short side length of 25 mm in the surface in contact with the cooling roll. An amorphous alloy ribbon characterized by having 5 or less scratches.   The amorphous alloy ribbon according to claim 1, wherein the dimension in the width direction perpendicular to the casting direction is 25 mm or more.   3. The amorphous alloy ribbon according to claim 1, wherein a center line average roughness Ra on a surface in contact with the cooling roll is 0.3 μm ≦ Ra ≦ 1.0 μm.

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