JP2002146492A - Laminated silicon steel sheet having excellent workability - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated silicon steel sheet having excellent shearing workability and hardly causing warp, peeling, etc., even if sheared into cores of small width and also having excellent workability. SOLUTION: The laminated silicon steel sheet having excellent workability is constituted by laminating two or more silicon steel sheets of <=0.25 mm thickness. Moreover, bonding layers and films each composed of organic resin having >=50 deg.C glass transition temperature or softening temperature are provided between the respective silicon steel sheets and to the respective surfaces of the silicon steel sheets on the outer sides, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated electromagnetic steel sheet used for a laminated core of a rotating machine, a transformer and the like.

[0002]

2. Description of the Related Art Due to the recent trend toward higher efficiency of rotating machines, transformers, and the like, higher performance is required for magnetic steel sheets used for iron cores. It is well known that if the thickness of an electromagnetic steel sheet used for a laminated core is reduced, iron loss is reduced, and therefore, many attempts have been made to reduce the thickness and achieve high performance. . However, 0.
When an electromagnetic steel sheet having a thickness of 2 mm or less is used, the number of laminations at the time of laminating the cores is increased and the working efficiency is reduced. In addition, since the strength of the steel sheet itself is low, there are problems such as bending and buckling.

[0003] Japanese Patent Laid-Open Publication No. 2000-17815 proposes an adhesive laminated electromagnetic steel sheet that achieves both improvement in iron loss and workability in core processing. However, if the magnetic steel sheets are simply laminated and bonded, bending, peeling, and the like occur in actual processing such as shearing and punching, which is disadvantageous. In particular, this problem becomes remarkable when the shear interval is narrow, such as when a tooth portion or a core having a small width is manufactured.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a heat-adhesive type insulating film which is excellent in workability and hardly bends or peels off even when subjected to shearing into a narrow core. An object of the present invention is to provide a laminated electromagnetic steel sheet.

[0005]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors, as shown in FIG.
a and 1b, an organic resin layer 2 is provided to bond both steel plates, and further, organic resin coatings 4a and 4b are provided on an outer surface 3a of the electromagnetic steel plate 1a and an outer surface 3b of the electromagnetic steel plate 1b, respectively. Experiments 1 and 2 were conducted on the relationship between the thickness and Cr amount of the laminated electromagnetic steel sheet, the glass transition temperature of the organic resin used, and the shearability of the obtained laminated electromagnetic steel sheet. And 3 were performed.

[0006] In Experiment 1, an Fe-Cr-Si-based magnetic steel sheet (component composition: Cr 4.5% by mass, Si 3.9% by mass, C
+ N19 mass ppm or less, balance iron and unavoidable impurities) and Fe—Si-based magnetic steel sheet (Si: 1.85 mass%), each having a different plate thickness, and having a glass transition temperature of 80 ° C. as an organic resin. Laminated electromagnetic steel sheet samples were prepared using an acrylic resin in the same manner as in the examples described below, and the shearing workability was evaluated in the same manner as described below. The result is shown in FIG.

Experiment 2 was carried out on a 0.1 mm thick Fe—Cr—Si based magnetic steel sheet having the above-mentioned composition and a Fe—Cr—Si based steel sheet.
A sample of a laminated electromagnetic steel sheet having a structure shown in FIG. 1 was prepared using an Si-based electromagnetic steel sheet and an acrylic resin having a different glass transition temperature as an organic resin, and the shear workability was evaluated in the same manner as described below. did. The result is shown in FIG.

In Experiment 3, three types of Fe—Cr—Si magnetic steel sheets having a thickness of 0.1 mm and having different Cr contents were used, and an acrylic resin having a glass transition temperature of 80 ° C. and 35 ° C. was used as an organic resin. A sample of a laminated electromagnetic steel sheet having the structure shown in FIG. 1 was prepared using the resin, and the shearing workability was evaluated in the same manner as described below. FIG. 4 shows the results.

As a result of the above experiments 1 to 3, it is effective to use a magnetic steel sheet having a thickness of 0.25 mm or less for the shearing workability of the laminated electromagnetic steel sheet. The present inventors have found that the use of an organic resin having a glass transition temperature of 50 ° C. or higher can provide good shearing workability, and the present invention has been made.

That is, the present invention has been made based on the above findings,
A laminated electromagnetic steel sheet obtained by laminating two or more electromagnetic steel sheets having a thickness of 0.25 mm or less, wherein a glass transition temperature or a softening temperature is 50 ° C. between each electromagnetic steel sheet and the surface of the electromagnetic steel sheet.
Provided is a laminated electromagnetic steel sheet having excellent workability, which is provided with an adhesive layer and a coating made of the above-described organic resin (hereinafter, referred to as “laminated electromagnetic steel sheet of the present invention”). Further, as can be seen from the results of Experiment 3, Cr 1.5 to 20
It is preferable to use an electromagnetic steel sheet containing 0.1% by mass in order to obtain good shear workability.

Hereinafter, the present invention will be described in more detail. The laminated electromagnetic steel sheet of the present invention is obtained by laminating and bonding two or more electromagnetic steel sheets (electric steel sheets). Known electromagnetic steel sheets can be used as the respective electromagnetic steel sheets to be laminated, and any one of non-directional, one-directional, and two-directional may be used.

Although the chemical composition of the laminated electromagnetic steel sheets is not particularly limited, it is preferable to use an electromagnetic steel sheet containing 1.5 to 20% by mass of Cr, since the shear workability is further improved. Although the reason is not clear, it is considered that a Cr-based surface oxide film was formed on the surface of such an electromagnetic steel sheet, and the adhesion to the organic resin was increased. Further, in the case of such an electromagnetic steel sheet, the toughness is improved, but a single ultra-thin steel sheet tends to easily cause a problem such as bending. It is considered that the strength is increased by stacking two or more sheets, and the further improvement in the shearing processability is also affecting.

Further, Cr is a basic alloying component that greatly improves electric resistance by a synergistic effect with Si, reduces iron loss in a high frequency range, and further improves corrosion resistance. Even when about 5% by mass or more of Si is contained, it is extremely effective for obtaining toughness to the extent that warm rolling is possible, and from that viewpoint, 2% by mass or more is preferable. When the amount of Si is smaller than the above case, the workability can be ensured even if the amount of Cr is further reduced. However, the effect of improving the workability of Cr is exhibited, and the specific resistance of the alloy is 60 μΩcm.
As described above, in order to improve iron loss in a high frequency range, 1.5%
More than mass% of Cr is preferred. On the other hand, if it exceeds 20% by mass, the effect of improving toughness is saturated and the cost is increased. Therefore, the content of Cr is 1.5 to 20% by mass, preferably 2 to 10% by mass, and more preferably 3 to 10% by mass. 7% by mass
Range.

[0014] Si is a component effective for greatly increasing electric resistance by a synergistic effect with Cr and reducing iron loss in a high frequency range. However, if it exceeds 10% by mass, Cr
, The toughness to the extent that warm rolling is possible cannot be ensured, so the Si content is 10% by mass or less, preferably 2.5 to 7% by mass or less, more preferably 3.0 to 5% by mass or less. Range.

C and N are preferably reduced as much as possible in order to deteriorate the toughness of the Fe—Cr—Si alloy, and the allowable amounts thereof are 1.5% by mass or more of Cr and 2.% of Si in the present invention. When the content is 5% by mass or less, it is preferable to suppress the total amount to 100% by mass or less in order to secure high toughness. Preferably 60 mass ppm or less,
It is more preferably at most 30 ppm by mass. In addition, as for each of C and N, C is preferably 30 mass ppm or less, N is preferably 80 mass ppm or less, and more preferably C is 10 mass pp.
m or less, and N is preferably 20 mass ppm or less. Also, C, N
The amount of impurities other than the above is not particularly limited, but S: 20 mass p
pm or less, preferably 10 ppm by mass or less, more preferably 5 ppm by mass or less. O: 50 mass ppm or less, preferably 30 mass ppm or less, more preferably 1 mass ppm or less.
5 mass ppm or less is good. Or the impurity C + S + N +
The total amount of O is preferably 120 ppm by mass or less, more preferably 50 ppm by mass or less.

[0016] It is known that Mn and P further increase the electric resistance by being further added to an Fe-Cr-Si alloy. By the addition of these components, a further reduction in iron loss can be achieved without impairing the spirit of the present invention. Therefore, in the present invention, Mn, P
One or two selected from the following may be contained. Nevertheless, adding a large amount of these components leads to an increase in cost. Therefore, the upper limit of each addition amount is 1% by mass. More preferably, it is 0.5 mass% or less.

In the present invention, the addition of a conventionally known alloy component for the purpose of further improving the magnetic properties, corrosion resistance, workability, etc. does not impair the effects of the present invention. It is also possible to include components. Representative examples of those components are listed below.
Ni of 5% by mass or less is a component for improving corrosion resistance, lowers the ductile-brittle transition temperature, improves workability, and suppresses eddy current loss because it is easy to make crystal grains fine.
It is also effective in reducing high frequency iron loss. 1 mass% or less of Cu
Has the same effect as Ni. Mo or W of 5% by mass or less
Improves corrosion resistance. La, V or Nb of 1% by mass or less,
0.1% by mass or less of Ti, Y or Zr, and 0.1% by mass or less of B have the effect of increasing toughness and improving workability.
Co of 5% by mass or less improves the magnetic flux density and is effective in reducing iron loss. 0.1 mass% or less of Sb and Sn
Is effective for improving the texture and for reducing the iron loss.

The thickness of each magnetic steel sheet used in the present invention must be 0.25 mm or less, and is preferably 0.05 to 0.23 mm. In this case, since the plate thickness is thin, the adhesive strength between the organic resin and the electromagnetic steel plate becomes relatively stronger than the bending stress of the plate itself. As a result, it is considered that peeling hardly occurs in shearing. On the other hand, when the plate thickness exceeds 0.25 mm, the sheet tends to bend at the time of shearing and is easily peeled.

In the present invention, the organic resin constituting the coating provided between the magnetic steel sheets and on the surface of the magnetic steel sheet on the outer side is not particularly limited. For example, acrylic resin, epoxy resin, phenol resin, urethane resin, Styrene-based, vinyl-based, and other organic resins that exhibit adhesiveness when heated and pressed can be used. Examples of the acrylic resin include methyl acrylate, ethyl acrylate, butyl acrylate, stearyl acrylate, glycidyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, stearyl methacrylate, glycidyl methacrylate, and the like. Examples of the epoxy resin include bisphenol A type, halogenated bisphenol A type, novolak type, polyglycol type, and bisphenol F type epoxy resins. Examples of the phenolic resin include novolak-type and resol-type phenolic resins. Examples of the urethane-based resin include amine-modified urethane, epoxy-modified urethane, and phenoxy-modified urethane. Examples of the styrene resin include polystyrene, acrylonitrile styrene resin, and acrylonitrile butadiene styrene resin. Examples of the vinyl resin include polyvinyl acetate. Further, a mixture of two or more organic resins may be used as the organic resin.

If necessary, the organic resin may contain an additive such as an amine curing agent or silica to such an extent that the effect of the present invention is not impaired.

The organic resin used in the present invention must have a glass transition temperature or a softening temperature (softening point) of 50 ° C. or more, and particularly preferably a resin having a temperature of 60 to 150 ° C. The glass transition temperature or softening temperature can be adjusted by appropriately mixing the above resins or by the amount of additives. For example, when 98 parts of methyl methacrylate is mixed with 2 parts of acrylic acid, a resin having a glass transition temperature of 105 ° C. is obtained. When 75 parts of methyl methacrylate, 7 parts of hydroxyethyl methacrylate, 3 parts of acrylic acid, and 15 parts of ethyl acrylate are mixed, glass is obtained. A resin having a transition temperature of 75 ° C. is obtained. In the shearing process, it is necessary that the bonded plate does not shift, bend or peel, but if the glass transition temperature or softening temperature is less than 50 ° C, it will be close to the actual working environment temperature, It is considered that the strength of the base resin itself is reduced, the plates are likely to be displaced and peeled off, and the effect of overlapping is reduced, so that the shearing processability is deteriorated.

Further, in order to further improve the performance of the film, an additive such as a rust preventive may be blended. In this case, the total amount of the additives is preferably in the range of 3 to 300 parts with respect to 100 parts of the organic resin in order to ensure the performance after the strain relief annealing.

In the laminated magnetic steel sheet of the present invention, the thickness of the organic resin film provided between the respective magnetic steel sheets is not particularly limited, but is preferably about 1 to 50 μm, and more preferably 5 to 20 μm. If it is less than 1 μm, a sufficient bonding area cannot be obtained, and the bonding strength decreases. If it exceeds 50 μm, the ratio of the organic resin layer to the thickness of the electromagnetic steel sheet of 0.25 mm = 250 μm or less increases, and the space factor decreases.

In the laminated electromagnetic steel sheet of the present invention, the thickness of the organic resin film provided on the outer surface of the laminated electromagnetic steel sheet is not particularly limited, but is preferably about 0.5 to 25 μm, more preferably 2 to 25 μm. 0.5 to 10 μm. With this thickness, there is sufficient interlayer resistance,
Sufficient bonding strength can be exhibited even when bonding by pressure. In addition, it may be provided on either one surface of 4a or 4b in FIG. 1 or may be provided on both surfaces.

The method for producing the laminated electromagnetic steel sheet of the present invention is not particularly limited, and examples thereof include the following method. An aqueous emulsion or dispersion of an organic resin is applied to both sides of a magnetic steel sheet by various methods such as a roll coater method, a flow coater method, a spray coating, and a knife coater,
A baking process is performed according to a conventional method such as a hot air system, an infrared system, or an induction heating system to form a film made of an organic resin on both surfaces. Laminate the required number of steel sheets, hot press,
A method of bonding magnetic steel sheets by applying heat and pressure using a heat-pressing roll or the like, or laminating a required number of magnetic steel sheets having a coating made of an organic resin on both sides, winding them up in a coil shape, and then heating. And any other method. It is considered that the method using a coil shape has high productivity and is practical.

The laminated electromagnetic steel sheet of the present invention can be used by being laminated as it is after punching into a core. However, it is further heated by utilizing the fact that an organic resin film having an adhesive property is present on the surface.・ It can be made into a block by applying pressure.

[0027]

EXAMPLES Hereinafter, the present invention will be specifically described based on examples.
I will tell. (Examples 1 to 20, Comparative Examples 1 to 9)
Electrical steel sheet having the sheet thickness, component composition and specific resistance described in
(Electromagnetic steel sheet) has the glass transition temperature or softening shown in Table 1.
Apply water-based organic resin with temperature using a roll coater
After baking at an ultimate plate temperature of 260 ° C, allow to cool and
An electromagnetic steel sheet with an insulating coating having a thickness of 5 μm was obtained. next,
The electromagnetic steel sheets were laminated in the number shown in Table 1 and hot-pressed.
200 ° C., pressure 10 kg / cm using ^Two, Time 1
Heating and pressing were performed under the conditions of minutes to obtain a laminated magnetic steel sheet.

Organic Resin An acrylic organic resin was prepared by mixing one or more of the above-mentioned acrylic resins and adjusting the glass transition temperature to a value shown in Table 1. The epoxy-based organic resin is obtained by mixing at least one of the epoxy resins exemplified above and having a softening temperature of Table 1.
Was adjusted so as to have the value shown in FIG. The glass transition temperature is based on JIS K7121, and the softening temperature is based on JIS K7121.
Each measurement was performed based on K7206.

The obtained laminated electromagnetic steel sheets were evaluated for shear workability according to the following method. Table 1 shows the results
Shown in

Shear workability The laminated adhesive steel sheet (50 × 100 mm) was sheared to a width of 5 mm by a shearing machine, and the peeled state of the sheared small pieces was visually observed and evaluated according to the following criteria. ；: No bending or peeling ○: There is peeling such as cracks, but there is no problem without bending or separation of the plate. 状態: Slight bending and partial peeling are observed. ×: Curving or peeling is observed. Separated by some force or separated

[0031]

[Table 1]

[0032]

[Table 2]

As is clear from Table 1, all of the examples of the present invention are superior to the comparative examples in shear workability.

[0034]

The laminated electromagnetic steel sheet of the present invention is excellent in shearing workability. Therefore, even if a narrow core is subjected to shearing processing such as punching or punching, the sheet shape is damaged by bending and the sheet is peeled off. Hateful. Therefore, the laminated magnetic steel sheet of the present invention is suitable as a material for a laminated core of a rotating machine, a transformer and the like.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing a laminated electromagnetic steel sheet used in an experiment on the thickness and Cr content of an electromagnetic steel sheet, the glass transition temperature of an organic resin, and shearing workability.

FIG. 2 is a view showing the results of an experiment on the sheet thickness and shear workability of an electromagnetic steel sheet.

FIG. 3 is a diagram showing the results of an experiment on the glass transition temperature and shear workability of an organic resin.

FIG. 4 is a diagram showing experimental results on the Cr content and shear workability of an electrical steel sheet.

[Explanation of symbols]

 1a, 1b Magnetic steel sheet 2 Organic resin layer 3a, 3b Outer surface of magnetic steel sheet 4a, 4b Organic resin film

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Osamu Kondo, Inventor 1-chome, Kawasaki-dori, Mizushima, Kurashiki-shi, Okayama Pref. Inside the Mizushima Works, Kawasaki Steel Corporation (72) Inventor, Masaki Kawano 1, Mizushima-Kawasakidori, Kurashiki-shi, Okayama Chome (without address) Inside Mizushima Works, Kawasaki Steel Corporation (72) Inventor Honda Atsuto 1-chome, Mizushima, Kawasaki-dori, Kurashiki City, Okayama Prefecture (without address) Inside Mizushima Works, Kawasaki Steel Corporation F-term (reference) 4D075 CA01 CA50 DA06 DB02 DC19 DC50 EA35 EB22 EB32 EB33 EB38 EB53 4F100 AB03A AB03B AB13A AB13B AK01C AK01D AK01E AK25 AK53 BA05 BA06 BA10D BA10E BA13 GB48 GB51 JA04C JA04D JA04E JA05C JA05D JA05EY00Y JA00YY00Y

Claims (2)

[Claims] 1. A laminated electromagnetic steel sheet in which two or more electromagnetic steel sheets having a thickness of 0.25 mm or less are laminated, wherein a glass transition temperature or a softening temperature is 50 ° C. between and between the respective electromagnetic steel sheets. A laminated electromagnetic steel sheet excellent in workability, characterized by having an adhesive layer and a coating made of the above organic resin. 2. The magnetic steel sheet according to claim 1, wherein Cr is 1.5 to 20% by mass.
The laminated electromagnetic steel sheet having excellent workability according to claim 1, comprising: