JP2006316348A - Thin ribbon of amorphous iron alloy - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin ribbon of an amorphous iron alloy in which the increase of magnetic flux density, the improvement of thermal stability, amorphousness, and processability, and the reduction of iron loss in an Fe-B-Si-based amorphous alloy are obtained. <P>SOLUTION: Regarding the thin ribbon of an amorphous iron alloy, adequate amounts of N, C and P are incorporated into a thin ribbon of an Fe-B-Si-based amorphous alloy, thus its thermal stability, amorphousness, processability (brittleness) and iron loss are improved without remarkably deteriorating its magnetic flux density. The thin ribbon of an amorphous iron alloy comprises 5 to 25 at.% B, 1 to 30 at.% Si, 0.001 to 0.2% N, 0.003 to 10% C, and 0.001 to 0.2% P, the remainder being iron and unavoidable impurities. In the thin ribbon, the ≤15% iron can be replaced with one or more members selected among up to 15% cobalt and nickel and up to 5% chromium. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an Fe-based amorphous alloy ribbon used for iron cores such as power transformers and high-frequency transformers. In particular, the present invention relates to a Fe-based amorphous alloy ribbon having a high magnetic flux density and excellent in thermal stability, amorphous shape performance, workability and iron loss.

  Technical issues of using amorphous alloy ribbons as iron core materials for power transformers, high-frequency transformers, etc. include the amount of materials used in transformer production compared to the use of silicon steel sheets, such as iron cores and copper wires. This increases the manufacturing cost. This is because many of the amorphous alloy ribbons have a low saturation magnetic force and the design magnetic flux density in the transformer has to be lowered. As a result, the iron core cross-sectional area increases. is there.

Therefore, various studies have been made to improve the magnetic flux density of the amorphous alloy ribbon. For example, in Patent Document 1, a saturation magnetic flux density of 1.57 to 1.61 T (Tesla) is obtained in an amorphous alloy ribbon having a composition of Fe ₈₀ B ₂₀ , and embrittlement occurs by adding Si and P. It has been proposed that the temperature and ductility can be improved. In Patent Document 2, although high magnetic flux density is confirmed by adding Co in an Fe—B—Si—C-based amorphous alloy ribbon, since Co is an expensive element, it is difficult in terms of cost. There is. Therefore, as a component system capable of realizing a high magnetic flux density without using Co, Non-Patent Document 1 introduced an Fe—B—C-based amorphous alloy ribbon, and in this component system, 1.78 T is obtained. Although it has been reported that the saturation magnetic flux density has been achieved, the iron loss is lower than that of the Fe-B-Si-C amorphous alloy ribbon, and the magnetic characteristics are stable during annealing and transformer operation. There is a problem that the thermal stability represented is low.

  Furthermore, Patent Document 3 proposes that the allowable amount of impurity elements such as S and Mn can be increased by adding a trace amount of P: 0.008 to 0.1% by mass. The impact on mechanical stability and workability (brittleness) has not been evaluated. Patent Document 4 proposes increasing the hardness of the ribbon, improving the maximum magnetic permeability, and improving the iron loss by adding N to the amorphous alloy ribbon containing Cr. However, thermal stability still remains. The processability problem has not been solved.

Japanese Patent Laid-Open No. 03-264654 Japanese Patent Laid-Open No. 03-5000668 JP 09-95760 A JP-A-62-74050 Hatta et al .: JEEEE Trans. Magnetics MAG-14 (1978) 1013

  In order to increase the magnetic flux density of the Fe-B-Si-based or Fe-B-Si-C-based amorphous alloy ribbon, it is effective to reduce the amount of components other than Fe. If it does so, there exists a problem that thermal stability, an amorphous formation ability, workability (brittleness), and an iron loss are not improved. In addition to this, an Fe-based amorphous alloy ribbon capable of obtaining stable iron loss using an inexpensive iron source has not been obtained so far.

The present inventors have added an impurity element (Al or the like), which is said to be a crystallization promoting element, by adding N to an Fe-B-Si-based and Fe-B-Si-C-based amorphous alloy. It has been found that it can be concentrated on the surface oxide layer, which prevents crack propagation in the amorphous alloy ribbon and greatly improves the workability. This N-containing effect eliminates the problem of containing P, which is particularly effective in improving the performance of low iron loss and amorphous form (the inclusion of P makes it easier for cracks to propagate through the ribbon). This makes it possible to produce an Fe-based amorphous alloy ribbon having a high magnetic flux density and excellent in thermal stability, amorphous form performance, workability (brittleness), and iron loss.
In addition, the inclusion of N in addition to P is a thin-band embrittlement that occurs when part of Fe is replaced with Ni, Co, Cr for the purpose of improving magnetic flux density, corrosion resistance characteristics, annealing conditions, and the like. It also turned out to be effective in improving the problem.
Based on these findings, studies have been repeated and the present invention has been completed. The summary is as follows.
(1) Fe containing at least 5% by atom, B: 5 to 25%, Si: 1 to 30%, N: 0.001 to 0.2%, and remaining Fe and unavoidable impurities Amorphous alloy ribbon.
(2) Atomic%, and further comprising one or two of C: 0.003 to 10% and P: 0.001 to 0.2%, the balance being Fe and unavoidable impurities The Fe-based amorphous alloy ribbon according to (1).
(3) Atomic%, B: 10-20%, Si: 1-10%, N: 0.001-0.2%, C: 0.02-2%, P: 0.001-0.2 %, The Fe-based amorphous alloy ribbon according to (2).
(4) Atomic%, B: 5-12%, Si: 1-5%, N: 0.001-0.2%, C: 1-10%, P: 0.001-0.2%, (2) The Fe-based amorphous alloy ribbon according to (2).
(5) The term according to any one of (1) to (4), wherein 15% or less of the amount of Fe in atomic% is substituted with Co, Ni or 5% or less with one or more kinds of Cr. 2. An Fe-based amorphous alloy ribbon described in 1.

  According to the present invention, it is possible to provide a Fe-based amorphous alloy ribbon having a high magnetic flux density and improved thermal stability, amorphous forming ability, workability (brittleness), and iron loss. Become.

  First, the component composition and its range in the present invention will be described. The range of the component composition is atomic% unless otherwise specified.

  B is an element effective for improving the amorphous forming ability and the thermal stability, and an appropriate amount is added according to the requirements of each characteristic. If B is less than 5%, an amorphous phase cannot be stably obtained. On the other hand, if B exceeds 25%, formation of the amorphous phase becomes difficult due to an increase in melting point. When importance is attached to low iron loss and thermal stability, B is preferably 10 to 20%, and when importance is placed on high magnetic flux density, it is necessary to reduce the metalloid element, so 5 to 12%. It is preferable.

  Similarly, Si is an element effective for improving amorphous forming ability and thermal stability, and an appropriate amount is added according to the requirements of each characteristic. If Si is less than 1%, an amorphous phase cannot be stably formed, while if it exceeds 30%, the effect of improving thermal stability is saturated. When importance is attached to low iron loss and thermal stability, Si is preferably 1 to 10%, and when importance is attached to high magnetic flux density, it is necessary to reduce the metalloid element, so 1 to 5%. It is preferable.

N is an element effective for improving thermal stability, amorphous form performance, and workability (brittleness) of the amorphous ribbon, and an appropriate content is determined according to the requirements of each characteristic. If N is less than 0.001%, these characteristics are not improved, while if it exceeds 0.2%, the effect of thermal stability is saturated. N is preferably about 0.003%, 0.004%, 0.006%, 0.007%, 0.008%, 0.009%, or 0.02%, 0.03%, 0.0. It may contain about 04% and 0.05%. On the other hand, the addition of N exceeding 0.1% increases the cost. Preferably, the addition cost decreases if it is about 0.09%, 0.08%, 0.07%, or 0.06%.
In the case where Co, Ni, and Cr are contained using an iron source containing impurities, N is not necessarily required to be added, and N is not necessarily indispensable as an inevitable impurity. It may be contained.

  C is an element effective for improving the magnetic flux density of the ribbon and improving the amorphous form performance (improving castability), and an appropriate amount is determined according to the requirements of each characteristic. By containing C in an amount of 0.001% or more, preferably 0.003% or more, the wettability between the molten metal and the cooling substrate is improved, and a good ribbon can be formed. Further, when C is 0.01% or more, preferably 0.02% or more, an effect of improving the amorphous form performance is obtained, and more preferably 0.03%, 0.06%, 0.08%,. 1%, 0.15%, 0.2%, 0.3%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, or 1%, 2 %, 3%, 4%, 5% can also be contained. On the other hand, if it exceeds 10%, the effect of improving the magnetic flux density decreases. When importance is attached to low iron loss and thermal stability, C is preferably 0.02 to 2%, and when importance is attached to high magnetic flux density, the melting point rises to reduce the amount of B. It is preferable to add 1 to 10% of C.

  P is an element effective for improving iron loss and amorphous form performance, and an appropriate amount is contained according to the requirements of each characteristic. The inclusion of P improves the amorphous form performance and increases the allowable amount of impurity elements, but if P is less than 0.001%, the amorphous form performance improvement effect is not seen and the iron loss improvement effect is also seen. I can't. Inclusion of P improves the amorphous form performance, but on the other hand, as the P content increases, cracks are easily propagated to the ribbon, resulting in a problem that workability deteriorates. Further, when P exceeds 0.2%, the bending fracture diameter at the time of bending and breaking with the roll cooling surface of the amorphous ribbon becomes larger, and the workability (brittleness) of the amorphous ribbon is deteriorated. P is 0.002%, 0.003%, 0.004%, 0.006%, 0.008%, 0.01%, 0.02%, 0.03%, 0.04%, 0.0. 05%, 0.06%, 0.07%, 0.08%, and further 0.12% and 0.15% may be included.

  In the present invention, when 15% or less of the amount of Fe is replaced with one or more of Co, Ni or 5% or less of Cr, the amorphous thin ribbon is not embrittled and a good amorphous state is obtained. A thin ribbon is obtained. These elements are preferably 0.001%, 0.002%, 0.003%, 0.005%, 0.008%, 0.01%, 0.02%, 0.03%, 0.04 %, 0.05%, 0.06%, 0.07%, 0.08%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6 % May be included. However, Co and Ni have an effect of improving the magnetic flux density, but are expensive. Therefore, considering the raw material cost, it is preferable to keep the replacement to 10% or less, and further 5% or less of the Fe amount. More preferably, these elements may be 4%, 3%, 2%, 1% or less.

When an inexpensive iron source is used, for example, it is possible to use some steel types produced in a steelmaking process in which iron ore is a raw material as an alloy iron source, but the ribbon of the present invention is manufactured. The iron source for this is not limited to the steel type produced by this steelmaking process. Further, the trace component contained in the present invention may be positively added by an alloy or the like, or may be contained by actively utilizing an impurity component mixed from another alloy or the like.
Moreover, even if it contains well-known Ti, Zr, V, Nb, Mo, Cu etc. other than Fe, B, and Si as a constituent element in the component of this invention, the effect of this invention is not impaired at all. In particular, Ti and Zr are known to be effective for improving the amorphous forming ability, and these may be contained in an amount of about 0.01 to 5%.

  The ribbon of the present invention is a method for melting the alloy component of the present invention, spraying the molten metal on a cooling plate moving at high speed through a slot nozzle or the like, and rapidly quenching and solidifying the molten metal, It can be produced by a twin roll process. The single roll device is equipped with a centrifugal quenching device that uses the inner wall of the drum, a device that uses an endless belt, and an auxiliary roll or roll surface temperature control device that is an improved version thereof, under reduced pressure or in vacuum Or a casting apparatus in an inert gas is also included. In the present invention, the thickness and width of the ribbon are not particularly limited, but the thickness of the ribbon is preferably 10 μm or more and 100 μm or less, for example. The plate width is preferably 20 mm or more.

<Example 1>
Single roll amorphous consisting of a 580 mm diameter copper alloy cooling roll (roll rotation speed 800 rpm), a high frequency induction melting device for sample dissolution, a quartz crucible, a slit nozzle 25 mm long and 0.6 mm wide provided at the crucible tip. Using an alloy ribbon manufacturing apparatus, an amorphous alloy ribbon having a width of 25 mm and a thickness of 28 to 35 μm was formed using the components shown in Table 1 in which N, C, and P were added to the Fe—B—Si component composition. Manufactured. The Fe source is converter steel with few impurities, B is added as Fe-B, Si is added as Fe-Si, C is added as pure C, P is added as Fe-P, N Was added by blending iron nitride in a nitrogen gas stream. Table 1 shows the component composition and the obtained characteristics. Various properties of the obtained amorphous alloy ribbon were measured by the methods described below.

1) The magnetic properties were obtained by annealing the obtained ribbon at 360 ° C. for 1 hour in a nitrogen atmosphere in a magnetic field and measuring it with a single-plate magnetometer (SST), with a magnetic flux density of 1.3 T and a frequency of 50 Hz. Evaluation was based on iron loss and magnetic flux density (B8) at a magnetic field of 800 A / m.
2) Thermal stability was measured with a vibrating sample magnetometer (VSM) using the Curie temperature as an evaluation index (the higher the Curie temperature, the more thermally stable).
3) Amorphous form performance was measured by measuring the crystallization temperature (Tp) and melting point (Tm) with a differential scanning calorimeter (DSC), and expressed as an evaluation index by Tp / Tm (the larger Tp / Tm is, Amorphous form performance is good).
4) Evaluation of brittleness was performed by measuring the bending fracture diameter when the amorphous ribbon after annealing in a nitrogen atmosphere at 360 ° C. for 1 hour was bent to the outside on the roll cooling surface side of the ribbon and fractured (bending) The larger the fracture diameter, the worse the brittleness).
When an amorphous ribbon is used for an iron core such as a power transformer or a high-frequency transformer, the amorphous ribbon is very thin and is usually used as a wound iron core. Therefore, brittleness is a particularly important characteristic when manufacturing iron cores. As a result of investigation by the present inventors, the bending fracture radius used as a brittleness evaluation index needs to be 4 mm or less. It was also found from the manufacturing conditions such as the annealing temperature and the design conditions that Tp / Tm is 0.5 or more and the Curie temperature is 350 ° C. or more. On the other hand, the iron loss and the magnetic flux density are selected as necessary because they are related to the design of the iron core. (Generally, low iron loss and high magnetic flux density are required. For example, even if the iron loss is slightly high, the high magnetic flux density is preferentially designed. Low iron loss is important and the magnetic flux density is not considered very important. , Selected according to the target device.)

Table 1 shows component compositions and evaluation results of the inventive examples and comparative examples that obtain a high magnetic flux density with low iron loss related to the first and second aspects of the present invention. In Table 1, Comparative Example 1 is an Fe-B-Si amorphous ribbon and does not contain any of N, C, and P, and has a base component composition. The magnetic properties, thermal stability, amorphous shape performance, and brittleness of the amorphous ribbon obtained by adding N, C, and P to Comparative Example 1 were evaluated.
Invention Example 1 contains 0.004% of N relative to Comparative Example 1, and has improved thermal stability, amorphous form performance, and brittleness. In Example 2 of the present invention, since 0.93% of C and 0.004% of N are contained, the magnetic flux density is also improved. On the other hand, Example 3 of the present invention contains 0.1% P and 0.004% N, so that the iron loss is good. In Invention Example 4, C is 0.93%, P is 0.1%, and N is 0.004%. In all of thermal stability, amorphous form performance, brittleness, magnetic flux density, and iron loss. It has been improved. In Inventive Example 5, C and N are the same as in Inventive Example 4, but 0.2% of P is contained, and the magnetic flux density is slightly reduced by the reduction of Fe, but the iron loss value is greatly improved. Amorphous form performance and brittleness were also improved. On the other hand, in Comparative Example 2, P was excessively contained at 0.25%, so that the magnetic flux density was lowered and the brittleness was deteriorated. In Examples 6 to 8 of the present invention, the N content was changed after adding 0.93% C and 0.1% P. However, the magnetic flux density and the iron loss were not significantly changed. As the content increases, the thermal stability, amorphous form performance, and brittleness are improved. Comparative Example 3 contains N excessively at 0.25%, and the cost of adding N is high, but the thermal stability and amorphous forming ability are already saturated. The density is decreasing.
From the above, it can be seen that thermal stability, amorphous forming ability, workability (brittleness), and iron loss are improved.

<Example 2>
An Fe—B—Si—C—P—N-based amorphous alloy ribbon having a width of 25 mm and a thickness of 28 to 35 μm was produced in the same manner as in Example 1 with the components shown in Table 2. Table 2 shows the component composition and the obtained characteristics. The measurement method and the evaluation method are the same as those in Example 1.

Table 2 shows the composition of the components of the present invention and the comparative example, which have low iron loss, good workability, and a moderate magnetic flux density, and the evaluation results. In Table 2, Comparative Example 4 contains neither P nor N and has a base component composition. For Comparative Example 4, the magnetic properties, thermal stability, amorphous forming ability, and brittleness of an amorphous ribbon obtained by containing P and N were evaluated.
In Invention Example 9, 0.005% P and 0.004% N were added, and iron loss, brittleness, and thermal stability were improved. In Examples 10 and 11 of the present invention, the magnetic flux density is slightly reduced but the iron loss value is large because Fe is decreased when P: 0.1%, P: 0.2%, and N: 0.004%, respectively. Improved, amorphous form performance and brittleness were also improved. On the other hand, in Comparative Example 5, P was excessively contained at 0.25%, so that the magnetic flux density was lowered and the brittleness was deteriorated. Inventive Examples 12 to 14 contain P: 0.1% and show low iron loss, and the amorphous forming ability is also improved. However, as the N content increases, thermal stability, Crystalline shape performance and brittleness are improved. Comparative Example 6 contains excessively N: 0.25% and the cost of adding N is high, but the thermal stability and amorphous forming ability are already saturated, and the increase in N increases the magnetic flux. The density is decreasing.
From the above, it can be seen that the thermal stability, amorphous forming ability, workability (brittleness), and iron loss are improved even in the component composition of Table 2.

<Example 3>
An Fe—B—Si—C—P—N-based amorphous alloy ribbon having a width of 25 mm and a thickness of 28 to 35 μm was manufactured using the components shown in Table 3 in the same manner as in Example 1. Table 3 shows the component composition and the obtained characteristics. The measurement method and the evaluation method are the same as those in Example 1.

Table 3 shows the composition of the components of the present invention and comparative examples for obtaining a high magnetic flux density related to the invention of claim 4 and the evaluation results thereof. In Table 3, Comparative Example 7 contains neither P nor N and has a base component composition. The comparative example 7 was evaluated for magnetic properties, thermal stability, amorphous forming ability, and brittleness of an amorphous ribbon obtained by containing P and N.
Invention Example 15 contained 0.005% P and 0.004% N, and improved iron loss, brittleness, and thermal stability. In Examples 16 and 17 of the present invention, the magnetic flux density is slightly decreased but the iron loss value is large because Fe is decreased by containing P: 0.1%, P: 0.2%, and N: 0.004%, respectively. There was also an improvement in amorphous form performance and brittleness. On the other hand, in Comparative Example 8, P was excessively added at 0.25%, so that the magnetic flux density was lowered and embrittled. Inventive Examples 18 to 20 show low iron loss when P: 0.1% is added, and the amorphous form performance is also improved. However, the thermal stability is increased as the N content increases, Amorphous form performance and brittleness are improved. Comparative Example 9 contains an excessive amount of N: 0.25%, and the cost of adding N is high, but the thermal stability and amorphous forming ability are already saturated. The density is decreasing.
From the above, it can be seen that the thermal stability, amorphous forming ability, workability (brittleness), and iron loss are improved even in the component composition of Table 3.

<Example 4>
In the same manner as in Example 1, the Fe-B-Si-C-P-N type amorphous alloy ribbon with a width of 25 mm and a thickness of 28 to 35 [mu] m was changed to Fe, Co, Ni, Cr with the components shown in Table 4. Amorphous alloy ribbons replaced with were produced. Table 4 shows the component composition and the obtained characteristics. The measurement method and the evaluation method are the same as those in Example 1.

Table 4 shows the composition of the components of the inventive examples and comparative examples for the purpose of improving the magnetic flux density and the corrosion resistance related to the invention of claim 5 and the evaluation results. In Table 4, the inventive examples 21 to 24 are substituted with Fe for the magnetic flux density improvement, and the inventive example 25 is substituted with Ni. Inventive Example 21 is a component composition not containing C and P, Inventive Example 22 is a component composition not containing C, and Inventive Example 23 is a component composition not containing P. In Invention Example 26, Fe is replaced with Cr for the purpose of improving the corrosion resistance. In Invention Example 27, Fe is replaced by Co, Ni, and Cr for the purpose of improving both the magnetic flux density and the corrosion resistance. A small amount of Ni and Cr was inevitably mixed from the Fe source and an additive alloy such as Fe-B (for example, Ni: 0.03% and Cr: 0.05% in Invention Example 21 in Table 4). Comparative Examples 10 and 11 are examples that do not contain N with respect to Invention Examples 21 and 22, and Comparative Example 12 is an example that does not contain N with respect to Invention Example 23 and N and P with respect to Comparative Example 24. .
Moreover, Comparative Examples 12-14 are examples which do not contain N and P with respect to Invention Examples 24-27.
It can be seen that in all of the examples of the present invention, the bending fracture diameter is reduced by about 40% due to the N-containing effect, and is reduced to 4 mm or less, thereby improving brittleness. Moreover, the iron loss is also good due to the effect of P, and the brittleness due to the addition of P is also improved due to the effect of containing N.
From the above, it can be seen that even when Fe is replaced with Co, Ni, and Cr, the ribbon properties are improved by the effect of containing P and N.

  The alloy ribbon of the present invention is improved in thermal stability, amorphous forming ability, workability (brittleness), and iron loss by the effect of addition of N. Further, it can be widely used as an iron core for power transformers and high-frequency transformers, and further as a soft magnetic material for iron cores such as a magnetic shield material.

Claims (5)

Atomic%, B: 5-25%,
Si: 1 to 30%
N: 0.001 to 0.2%
Fe-based amorphous alloy ribbon characterized by comprising Fe and the balance Fe and inevitable impurities. Atomic%, and
C: 0.003 to 10%,
P: 0.001 to 0.2%
2. The Fe-based amorphous alloy ribbon according to claim 1, wherein the Fe-based amorphous alloy ribbon comprises at least one of the above and the balance Fe and unavoidable impurities. Atomic%
B: 10-20%
Si: 1 to 10%,
N: 0.001 to 0.2%,
C: 0.02 to 2%,
P: 0.001 to 0.2%
The Fe-based amorphous alloy ribbon according to claim 2. Atomic%
B: 5-12%,
Si: 1 to 5%
N: 0.001 to 0.2%,
C: 1-10%,
P: 0.001 to 0.2%
The Fe-based amorphous alloy ribbon according to claim 2.   The Fe system according to any one of claims 1 to 4, wherein 15% or less of the amount of Fe in atomic% is substituted with Co, Ni, or 5% or less with one or more of Cr. Amorphous alloy ribbon.