JP2001131718A - Silicon steel wire excellent in high frequency magnetic property and workability - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a silicon steel wire excellent in high frequency magnetic properties and workability, in which wire drawing and iron core working are easily executable, and moreover, deterioration in magnetic properties caused by working strain is extremely small. SOLUTION: The total content of C, S, O and N contained in steel is suppressed to <=0.025 wt.%, moreover, the wire diameter (t) is controller to 0.01 to 1.0 mm, and also, as for the wire diameter (t) and the crystal grain diameter (d), the relation in the rolling inequality of d<=80/(t+1.0) is satisfied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic steel wire excellent in high-frequency magnetic properties and workability suitable for use in iron core materials such as transformers and reactors.

[0002]

2. Description of the Related Art Oriented or non-oriented magnetic steel sheets have been used as iron core materials such as transformers and reactors. There are a stack type and a roll type in these iron cores, and in each case, precise processing such as slitting, shearing, or bending is required. However, especially when the core is relatively small, not only is the processing itself difficult, but also the volume of the distorted portion due to the processing in the entire core becomes large, so that the magnetic properties of the core deteriorate. There was a problem.

[0003] On the other hand, similarly to the present invention, a metal wire having excellent magnetic properties has been conventionally developed. For example,
Japanese Patent Application Laid-Open No. 59-215463 and Japanese Patent No. 2910288 propose to reduce the amount of Si, the amount of carbon, or the amount of ultra-low carbon in order to improve the magnetic properties and the cold drawability. However, in these methods, good iron loss characteristics cannot be obtained, and there is a problem that the iron loss particularly in a high frequency range is increased.

In this regard, Japanese Patent Application Laid-Open No. Sho 60-181234 discloses that annealing after drawing is performed in a decarburized atmosphere at 750 ° C.
By performing the following conditions or A ₃ transformation point, it is proposed to improve the texture. However, although this method is also excellent in magnetic flux density characteristics, satisfactory iron loss characteristics cannot be obtained. In addition, Japanese Unexamined Patent Publication
Japanese Patent No. 75311 attempts to improve drawability and magnetic properties by specifying hot rolling conditions, but this method still has a problem that iron loss is high. further,
Japanese Patent Application Laid-Open No. 56-167302 proposes a magnetic metal wire having an insulating coating for an iron core of an induction heating furnace. However, this method also has a problem that iron loss is deteriorated due to distortion during processing. there were.

[0005]

As described above, all of the prior arts have been developed mainly for large-diameter ones, so that these techniques are applied to wire drawing, particularly for diameter drawing. However, when wire drawing is performed to a fine wire having a thickness of 1.0 mm or less, or when processing is performed on an iron core, the texture is deteriorated, and therefore, there is a problem that the magnetic properties are greatly deteriorated due to processing strain. The present invention advantageously solves the above-mentioned problems of the prior art, and is excellent in high-frequency magnetic characteristics and workability, in which wire drawing and iron core processing are easy, and magnetic characteristics are hardly deteriorated due to processing distortion. The purpose is to propose a magnetic steel wire.

[0006]

Means for Solving the Problems The inventors made wires using various materials, prototyped a 300 W reactor using them, and compared their characteristics. As a result, when using a wire, in order to increase the efficiency of the reactor for high frequency, as shown in FIG. 1, the material for the iron core is excellent in high-frequency iron loss of W _1/10000 , It is necessary to have a high magnetic flux density. It is considered that the reason for this is that, as the high magnetic field magnetic flux density is higher, the saturation characteristics of the iron core are improved, and the loss at the time of DC superposition can be suppressed.

The present invention has been developed on the basis of the above-mentioned new findings, and clarifies the metallurgical conditions necessary for achieving the above. In other words, the magnetic wire is excellent in wire drawability, and the magnetic properties are less deteriorated due to processing distortion when processed into equipment that requires good magnetic properties especially at high frequencies, especially in reactors and transformers. It has been newly found that it is necessary to reduce trace impurity components contained in steel wires as much as possible and to strictly define the crystal grain size according to the wire diameter in order to obtain the actual magnetic properties of the actual machine. .

That is, the gist of the present invention is as follows. 1. The total amount of C, S, O and N contained in steel is 0.0
25 wt% or less, the diameter t is 0.01 mm or more and 1.0 mm or less, and the diameter t and the crystal grain size d (μm) satisfy the following relationship: d ≦ 80 / (t + 1.0) Electromagnetic steel wire with excellent magnetic properties and workability.

[0009] 2. The electromagnetic steel wire according to 1 above, wherein the steel further has a composition further containing Sb and / or Sn: 0.005 to 0.5 wt%.

[0010] 3. In the above 1 or 2, the steel further contains Si: 0.1 to 8.0 wt%, Mn: 3.0 wt% or less, Al: 2.0 wt% or less, Cu: 2.0 wt% or less, Cr: 0.1 to 15 wt%, Ni: 5.0 wt% % Or less, P: 0.2 wt% or less An electromagnetic steel wire excellent in high-frequency magnetic properties and workability, characterized in that it has a composition containing one or more kinds selected from the group consisting of:

The high-frequency magnetic characteristics targeted in the present invention are as follows: the iron loss W _{1/10000 at} 0.1 T, 10,000 Hz is 30 W /
the magnetic flux density B ₁₀₀ is 1 kg or less, and in 10000 A / m.
That is 55T or more.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. Si: 2.05 wt%, Al: 0.5 wt%, Mn: 0.5 wt% and P:
0.02wt% and a trace element (C + S + O +
N) Bloom with a total amount of 135 ppm and Si: 2.02wt
%, Al: 0.3 wt%, Mn: 0.7 wt%, and P: 0.02 wt%, and blooms each having a total amount of (C + S + O + N) of 292 ppm were prepared and used as hot-rolled wires having a diameter of 5 mm. After that, the wire was drawn to 0.2 mm in the cold. Then
Anneal for 2 minutes in a nitrogen atmosphere at 700 to 1,050 ° C, measure the average crystal grain size, make a ring core with an average diameter of 5cm, apply a 100-turn primary and secondary winding, and then measure the magnetism Was done.

FIG. 2 shows the results of an investigation on the effect of the crystal grain size on the iron loss W _1/10000 (W / kg). As is clear from the figure, the amount of trace elements (C + S + O + N) is large.
In the case of 92 ppm, good iron loss could not be obtained irrespective of the crystal grain size, whereas trace elements (C + S + O +
When the amount of N) was small and 135 ppm, the iron loss was remarkably improved as the crystal grain size became smaller.

Then, next, Si: 3 wt%, Al: 0.2 wt%
And Mn: containing 0.3 wt% and containing trace elements (C + S +
O + N) Bloom with a total amount of 210 ppm
Wire drawing was performed from m to 1.0 mm, and the same heat treatment, particle size measurement, and magnetic measurement as described above were performed. The obtained results are summarized in the relationship between the average crystal grain size and the wire diameter, and are shown in FIG. As shown in the figure, both the core loss and the magnetic flux density exhibit good values because of the wire diameter t (mm) and the average crystal grain diameter d.
(μm) was found to satisfy the relationship of the following equation. d ≦ 80 / (t + 1.0)

Thus, the trace element (C + S + O + N)
The reason why the magnetic properties are improved by reducing the amount as much as possible and making the crystal grain size smaller as the wire diameter becomes larger is as follows.
It is considered as follows. First, trace elements (C + S + O
+ N), the wire drawing processability is improved, thereby promoting the formation of a texture having good magnetic properties. Further, the reduction of these impurities is achieved by improving the texture of the wire through its texture improving effect. It is considered that the reduction in distortion during ring processing after removal is a reason for obtaining good magnetic properties. The relationship between the wire diameter and the crystal grain size is
It is thought that what was conventionally buried in the variation and did not appear clearly, but clearly appeared as a change in the magnetic characteristics due to the reduction of the amount of the trace element (C + S + O + N).
In other words, it is considered that the high purification makes it possible to achieve both good high magnetic field characteristics and good high frequency characteristics by well-balanced crystal grain size and texture according to the wire diameter.

Hereinafter, the reason why the composition of the steel wire is limited to the above range in the present invention will be described. (C + S + O + N) amount: 0.025 wt% or less Since all of these elements inhibit workability, particularly ductility, it is desirable to reduce them as much as possible. The total amount
It is important to reduce it to 0.025wt% (250ppm) or less. It is to be noted that desired characteristics can be obtained if these elements are suppressed in the above range in total, but it is particularly preferable to limit the respective elements to the following ranges.

C: 0.010 wt% or less C, if it exceeds 0.010 wt%, forms a solid solution in steel and causes strain aging during processing to deteriorate ductility. Therefore, it is preferable to make C 0.010 wt% or less. N: 0.0050 wt% or less N, like C, causes not only strain aging during processing and deterioration of ductility, but also a large amount of N forms nitrides and deteriorates the texture. % Is preferable. S: 0.010 wt% or less S deteriorates ductility by forming sulfide,
When finely dispersed, the crystal grain growth and iron loss are deteriorated. Therefore, the content is preferably set to 0.010 wt% or less. O: 0.0050 wt% or less O also deteriorates ductility and crystal grain growth due to the formation of oxides, so it is preferable that O be 0.0050 wt% or less.

Next, preferred additive components will be described. Sb and / or Sn: 0.005 to 0.5 wt% Both Sb and Sn are elements that are useful for improving texture, suppressing nitriding during annealing, and reducing deterioration due to processing strain. %, The effect is small. On the other hand, if it exceeds 0.5 wt%, the cold workability is deteriorated.
It is preferable to contain it in the range of 05 to 0.5 wt%.

Si: 0.1 to 8.0 wt% Si is a useful component for improving iron loss characteristics by increasing the electrical resistance of steel. However, if the content is less than 0.1 wt%, the effect of its addition is poor. If it exceeds 8.0 wt%, cold working becomes difficult, so it is preferable to set the content to about 0.1 to 8.0 wt%.

Mn: 3.0 wt% or less Mn is a useful component for increasing the electrical resistance of a steel wire and improving iron loss characteristics. However, if it exceeds 3.0 wt%, it undergoes α / γ transformation during recrystallization annealing. The texture deteriorates.

Al: 2.0 wt% or less Al is a useful component for increasing the electrical resistance of the steel wire and improving iron loss characteristics. However, if it exceeds 2.0 wt%, nitriding is promoted during recrystallization annealing, and The loss will deteriorate.

Cu: 2.0 wt% or less Cu is a useful component for increasing the electrical resistance of the steel wire and improving iron loss characteristics. However, if it exceeds 2.0 wt%, the steel becomes brittle,
Cold working becomes difficult.

Cr: 0.1 to 15 wt% Cr is a useful element that enhances the electrical resistance of the steel wire and improves iron loss characteristics, and has an effect when added in an amount of 0.1 wt% or more. The wire workability deteriorates.

Ni: 5.0 wt% or less Ni is a useful component for increasing the electrical resistance of the steel wire and improving iron loss characteristics. However, if it exceeds 5.0 wt%, cold workability is deteriorated.

P: 0.2 wt% or less P is a useful component for increasing the electrical resistance of the steel wire and improving iron loss characteristics. However, if it exceeds 0.2 wt%, cold workability is deteriorated.

[0026] The molten steel adjusted to the above-mentioned preferable composition is formed into a bloom having a predetermined thickness by continuous casting or ingot-bulking method, and then into a wire by hot rolling, and then once or twice including intermediate annealing. The above wire drawing is performed. afterwards,
After annealing or processing into an iron core, finish annealing is performed. Note that an insulating film may be coated to enhance the insulating property.

[0027]

EXAMPLES Blooms having various component compositions shown in Table 1 were prepared, and hot-rolled wire having a diameter of 5 mm was formed.
Wire drawing was performed to 0.05 to 1.2 mm. Then, 700 ~ 1050 ℃
For 2 minutes in a nitrogen atmosphere. A ring core having an average diameter of 5 cm was prepared from each of the obtained wire rods, and after a primary and secondary winding of 100 turns was applied, a magnetic measurement was performed. In addition, the workability is determined by the state of breakage during wire drawing,
When the wire was never broken during wire drawing, it was indicated by ○, and when broken even once, it was indicated by ×. Table 2 shows the obtained results.

[0028]

[Table 1]

[0029]

[Table 2]

As is evident from Table 2, all those satisfying the requirements of the present invention have better magnetic properties and workability than the comparative materials.

[0031]

As described above, according to the present invention, it is possible to stably provide an electromagnetic steel wire which is easy to wire-draw and iron-core, has very little deterioration in magnetic properties due to processing strain, and has excellent high-frequency magnetic properties and workability. Can be obtained.

[Brief description of the drawings]

FIG. 1 is a graph showing the effect of magnetic properties of a wire for an iron core on reactor loss.

FIG. 2 is a graph showing the influence of the amount of impurity elements and the average crystal grain size on the iron loss characteristics of a wire.

FIG. 3 is a graph showing the relationship between the wire diameter and the average crystal grain size that affect the magnetic properties of the wire.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Nobuhiro Shiga 1-chome, Mizushima-Kawasaki-dori, Kurashiki-shi, Okayama Pref.

Claims (3)

[Claims] 1. The total amount of C, S, O and N contained in steel is 0.025 wt% or less, the wire diameter t is 0.01 mm or more and 1.0 mm or less, and the wire diameter t and the crystal grain size d (μm ) Satisfying the following relationship: d ≦ 80 / (t + 1.0). An electromagnetic steel wire excellent in high-frequency magnetic properties and workability. 2. The electromagnetic steel wire according to claim 1, wherein the steel has a composition further containing 0.005 to 0.5 wt% of Sb and / or Sn. 3. The steel according to claim 1 or 2, wherein the steel further comprises Si: 0.1 to 8.0 wt%, Mn: 3.0 wt% or less, Al: 2.0 wt% or less, Cu: 2.0 wt% or less, Cr: 0.1 to 15 wt%. %, Ni: 5.0 wt% or less, P: 0.2 wt% or less An electromagnetic steel wire excellent in high-frequency magnetic properties and workability, characterized by having a composition containing one or more selected from the group consisting of: