JP2002266017A - METHOD FOR MANUFACTURING Fe-Ni PERMALLOY ALLOY - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize the content of oxide nonmetallic inclusions whose existence is one of the main causes of the hindrance of the migration of magnetic domain walls. SOLUTION: At deoxidation treatment, the following treatments are performed: primary deoxidation treatment where oxygen concentration in atmosphere in a melting vessel is controlled to <=0.1 vol.% and an Si-Mn-based deoxidizer is added to carry out deoxidation; and secondary deoxidation treatment where an Al-based deoxidizer is added to the molten metal in the above vessel to control oxygen concentration in the molten alloy to <=50 ppm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head, a magnetic shielding material, a Fe-N used for a core of a transformer core, and the like.
The method for producing an i-based permalloy is characterized by a refining method mainly including a deoxidation method.

[0002]

2. Description of the Related Art Fe-Ni-based permalloy is usually made of PB (4
5wt% Ni), PC (78wt% Ni-Mo-Cu), etc. are typical. The former is mainly used for the application of the feature that the saturation magnetic flux density is large, for example, the stator of the watch, the pole piece of the magnetic lens. Many are used for such. On the other hand, the latter is used as a high-sensitivity transformer or a magnetic shield material in a high frequency region utilizing an excellent magnetic permeability.

A technique for improving the magnetic properties of this type of Fe—Ni-based permalloy is disclosed in, for example, Japanese Patent Application Laid-Open No. 05-00516.
In Japanese Patent Publication No. 2, {200} including the easy axis <100> is described.
A technique has been proposed in which surfaces are integrated in a plane at an integration intensity ratio of 2 or more. As a technique approached from the viewpoint of the influence of impurities or precipitates on magnetic properties, Japanese Patent Application Laid-Open No. 06-122947 discloses that S, B and O as impurity elements are S ≦ 0.003 wt% and B ≦ B. 0.005wt%, O ≦ 0.
We propose a method to regulate 005wt% and S + B + O ≦ 0.008wt%. That is, this technique proposes to suppress the impurity element on the assumption that the second phase such as a precipitate has a bad influence on the domain wall motion,
It is not an idea to directly control the nonmetallic inclusion itself.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to reduce the content of oxide-based nonmetallic inclusions, which is one of the factors that hinder domain wall movement, as much as possible. Oxygen is reduced by deoxidation using Al, and the oxide-based nonmetallic inclusions generated at this time are not greatly elongated during hot rolling, and are fine even in the final product. Difficult to disperse,
That Al ₂ O _3, and specific aims to propose a technique for controlling the MgO · Al ₂ O _3, MgO refractory oxide-based nonmetallic inclusions, such as.

[0005]

In order to achieve the above object, the present inventors first conducted a deoxidation experiment in a laboratory using a molten Fe-Ni permalloy alloy using various deoxidizing agents. went. As the refractory of the melting vessel used in this experiment,
Magnesia, alumina or spinel was used. The molten alloy thus obtained was cast into a mold to form an ingot, which was forged, hot rolled, and cold rolled to obtain a product having a thickness of 0.35 mm. Thereafter, magnetic annealing was performed at 1100 ° C. for 3 hours, and DC magnetization characteristics were examined. As a result, for permalloy alloy, when Al etc. is used as deoxidizer during finish deoxidation,
The oxygen concentration for refining nonmetallic inclusions decreases, and the oxide-based nonmetallic inclusions are in the form of one or more of Al ₂ O ₃ , MgO ・ Al ₂ O ₃ , and MgO, and have high magnetic permeability Was obtained. Further, before the final deoxidation, if about 0.05 to 0.25 wt% of C is added to the molten alloy and preliminarily deoxidized under a reduced pressure of 5 torr or less, inclusions during the final deoxidation with Al or the like. It was also found that the amount of generation could be further reduced and higher magnetic permeability could be obtained.

That is, according to the present invention, in producing a Fe-Ni-based permalloy containing 30 to 85 wt% of Ni, the oxygen concentration in the atmosphere in the melting vessel is controlled to 0.1 vol% or less when deoxidizing. In addition, a primary deoxidation treatment is performed in which a deoxidizing agent made of Si and / or Mn is added to perform deoxidation, and thereafter, Al or an Al-containing deoxidizing agent is further added to the molten alloy in the container, and A method for producing a Fe—Ni-based permalloy, characterized by performing a secondary deoxidation treatment for controlling the oxygen concentration in the steel to 50 ppm or less.

Further, the present invention relates to Fe-Ni containing 30 to 85 wt% of Ni.
In the production of a permalloy alloy, when performing deoxidation treatment, first, preliminarily deoxidize the molten alloy in the melting vessel,
As a finish deoxidation treatment, the oxygen concentration in the atmosphere in the melting vessel is controlled to 0.1 vol% or less, and Si and / or M
By performing deoxidation by adding a deoxidizing agent consisting of n, a primary deoxidation treatment is performed to reduce the oxygen concentration in the molten alloy to 100 ppm or less, and then, furthermore, Al or
Add an Al-containing deoxidizer to reduce the oxygen concentration in the molten alloy to 50 ppm
Performing a secondary deoxidation treatment controlled below
This is a method for producing an Fe-Ni-based permalloy.

In the present invention, the pre-deoxidation is performed by adding C or a C-containing deoxidizing agent under a reduced pressure of 5 torr or less in the atmosphere in the melting vessel to reduce the oxygen concentration in the molten alloy to 20%.
The oxygen concentration of the molten alloy after the primary deoxidation treatment is preferably 100 ppm or less.

Further, Fe-Ni produced by the method of the present invention
Series permalloy alloy contains 30-85wt% Ni,
Any one or more elements selected from o, Cu, Co and Nb, each containing 15 wt% or less and a total of 20 wt% or less, with the balance being Fe Preferably, there is.

Preferably, a high-frequency induction furnace is used as the melting vessel, and magnesia, alumina or spinel is used as an inner wall refractory in the melting vessel.

The alloy obtained by the production method according to the present invention containing 30 to 40% by weight of Ni has a maximum magnetic permeability μm of 30,000 or more, an initial magnetic permeability μi of 10,000 or more, and a coercive force Hc of 7.0 [ A / m] The magnetic properties of
%, The maximum magnetic permeability μm = 70,000 or more, the initial magnetic permeability μi = 10,000 or more, and the coercive force Hc = 5.0 [A / m] or less.The one containing 70 to 85 wt% of Ni is Maximum permeability μm = 300,000 or more, initial permeability μi = 200,000 or more, coercive force
It is a Fe—Ni-based permalloy exhibiting magnetic properties of Hc = 0.7 [A / m] or less.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION
-In the field of Ni-based permalloy, although it is different from steel production, the handling of deoxidizers is compared because the oxygen potential in the molten alloy after deoxidation must be reduced as much as possible. It is preferable to use a material which is easy and has a strong deoxidizing effect, and the use of Al is recommended. That is, Fe-
When Al is added to the molten Ni-based permalloy alloy, the following reaction occurs. _{2 Al +3 O = Al 2 O} 3 ( _inclusion)

According to the study by the inventors, it is necessary to add Al ≧ 0.001 wt% in order to efficiently advance this deoxidation reaction and reduce the oxygen concentration of the molten alloy to 50 ppm or less. know. However, if Al is added too much,
Lattice distortion occurs due to solid solution, and magnetic properties are deteriorated. Therefore, the preferred range of addition of Al as a deoxidizing agent is 0.00
1 ≦ wt% Al ≦ 0.05 is preferred.

When the Al is added in the finish deoxidation treatment, the oxygen concentration of the smelted alloy melt is 50 ppm
The content is adjusted to not more than 40 ppm, preferably not more than 40 ppm, more preferably not more than 30 ppm. The oxygen concentration of the alloy after finish deoxidation is 50 ppm,
The reason for adjusting the content to preferably 40 ppm or less, more preferably 30 ppm or less, is that the lower the oxygen concentration, the lower the absolute amount of nonmetallic inclusions, and the better the magnetic properties.

A feature of the present invention is that, as described above, deoxidation with Si and / or Mn is performed before finish deoxidation with Al (hereinafter, this deoxidation is referred to as "secondary deoxidation") (hereinafter, referred to as "secondary deoxidation"). This deoxidation is referred to as “primary deoxidation”. The reason why the final deoxidation is divided into primary and secondary is that if the oxygen concentration in the molten alloy is to be reduced to 50 ppm or less only by the final deoxidation with Al, Al must be added in a state where the oxygen concentration is high. Since it disappears, the generation amount of alumina-based nonmetallic inclusions increases, and sometimes even clusters are generated. Since such clusters have an apparent specific gravity similar to that of molten steel, there is a problem that a great amount of time is required for flotation separation.

In this regard, when the primary deoxidation step using Si and Mn is performed, manganese silicate-based inclusions which are liquid and have excellent separability are formed, and therefore, the manganese silicate-based inclusions may be clustered like Al ₂ O _3. And the total time required for finish deoxidation is significantly reduced.

In this case, in the primary deoxidation treatment using Si and Mn, the oxygen concentration in the molten alloy is adjusted to about 100 ppm or less. In this treatment, if it cannot be adjusted to about 100 ppm or less, not only the secondary finish deoxidation with Al takes a long time but also the total inclusion amount cannot be reduced until sufficient magnetic properties can be obtained.

In the present invention, the primary finish deoxidizing treatment is
The atmosphere in the melting vessel is controlled to an oxygen concentration of 0.1 vol% or less. The reason for controlling the oxygen concentration in the atmosphere to 0.1 vol% or less is as follows.
This is to prevent the oxygen contained in the atmosphere from oxidizing the deoxidizing agent when adding the deoxidizing agent. That is, it is to improve the efficiency of the deoxidizing agent and more efficiently remove oxygen in the molten steel.

In a more preferred embodiment of the present invention, C or a C-containing deoxidizing agent is added to 0.05 to 0.25 before the first finishing deoxidizing treatment.
This is a method of performing preliminary deoxidation by adding wt%. If C or C
In order to achieve the final deoxidation target of oxygen: 50 ppm or less without performing pre-deoxidation using the contained deoxidizer, the secondary finish deoxidation treatment with Al is performed, and the floating time of nonmetallic inclusions For more than 30 minutes.

In the step of the preliminary deoxidizing treatment, C or the like is replaced with Fe-Ni
After adding and dissolving about 0.05-0.25wt% in the molten permalloy alloy, it is treated under reduced pressure of 5torr or less, deoxidation proceeds by CO reaction, and oxygen is reduced to 200ppm or less. . After that, by performing the primary and secondary finishing deoxidation treatments, the total amount of nonmetallic inclusions can be suppressed, and the floating time of the nonmetallic inclusions can be reduced to 30 minutes or less. Can be shortened.

In the present invention, the composition of the nonmetallic inclusions formed is selected from the group consisting of alumina, spinel and magnesia.
In order to control at least one type, it is necessary to use a magnesia, alumina, or spinel-based refractory for holding molten steel in the melting vessel. When the refractory is alumina, nonmetallic inclusions are mainly alumina. However, when magnesia or spinel is used, the following reduction reaction occurs to generate dissolved Mg in the molten alloy. 3MgO _{(refractory) +2 Al = Al 2 O 3} ( _refractory) +3 M g and this Mg reacts with alumina-based inclusions, magnesia, sometimes produces a spinel.

Generated by performing the above processing,
Al ₂ O ₃ , MgO.Al ₂ O ₃ , MgO inclusions conforming to the present invention are:
Both are high melting point oxides and do not easily expand in the hot rolling step. Therefore, even in the final product, they are concentrated and not dispersed. For this reason, the concentration of the inclusions that hinder the movement of the domain wall becomes small, which leads to the improvement of the magnetic characteristics.

In the present invention, as a preferred example, a high-frequency induction furnace whose atmosphere can be controlled, such as a vacuum induction furnace, is used as a melting vessel for the above-mentioned preliminary deoxidation treatment and the deoxidation treatment of the first and second finishes. The reason for focusing on this furnace is that the atmosphere can be easily controlled to a reduced pressure, an inert gas atmosphere such as argon, and the heating can be easily performed.

In addition, the components adjusted as described above
The molten metal is then cast, agglomerated, hot rolled, and cold
Rolled and processed by conventional methods such as magnetic annealing
Therefore, Fe-Ni based permanent magnets having the following magnetic properties
It becomes possible to produce Roy alloys. That is, (i) when Ni: 30 to 40 wt% is contained, the maximum magnetic permeability μm: 3
0,000 or more, initial permeability μi: 10,000 or more, and coercive force Hc:
Fe-Ni permalloy alloy showing magnetic properties of 7.0 [A / m] or less
Money. (ii) Ni: When containing 40 to 50 wt%, the maximum magnetic permeability μm:
70,000 or more, initial permeability μ _i: 10,000 or more and coercive force H
c: Fe-Ni-based permalloy showing magnetic properties of 5.0 [A / m] or less
alloy. (iii) Ni: maximum magnetic permeability μ when 70-85 wt% is contained
m: 300,000 or more, initial permeability μ_i: 200,000 or more and coercivity
Fe-Ni-based permanent magnet showing magnetic properties of force Hc: 0.7 [A / m] or less
Roy alloy.

The material to which the method of the present invention is applied is a Fe—Ni-based permalloy alloy having a Ni content of 30 to 40 wt% and 40 to 50 watts.
t% and 70 to 85 wt%, and the balance is mainly composed of Fe. Of course, in some cases Mo, Cu,
Also used is one in which one or two elements selected from Co and Nb are added in an amount of 15 wt% or less, respectively, and a total of 20 wt% or less. Mo and Cu are useful elements for controlling the generation conditions of the ordered lattice of the PC material. Co has the function of increasing the magnetic flux density and at the same time improving the magnetic permeability by adding an appropriate amount. Nb is an indispensable component for applications such as a magnetic head because it has little effect on magnetic properties, but increases the hardness of the material and improves wear resistance. If each of the above elements (Mo, Cu, Co, Nb) exceeds 15% by weight, the content of Fe decreases and the saturation magnetic flux density decreases. Therefore, each of the above elements is 15 wt% or less, preferably 1 to
The range is 15wt%. On the other hand, if the sum of them exceeds 20 wt%, the content of Fe decreases similarly, and the saturation magnetic flux density decreases. Therefore, the total of the above elements is limited to 20 wt% or less.

[0026]

EXAMPLE After melting 5 kg of a Fe-Ni-based permalloy alloy adjusted to the composition shown in Tables 1 to 3 in a vacuum induction furnace in which the inside of the furnace was replaced with Ar, 0.05 to 0.25 wt% of C was added. , 5t inside the furnace
Perform pre-deoxidation under reduced pressure to orr, add Si, Mn and add 1
After performing the second finishing deoxidation, Al was further added to perform the second finishing deoxidation. As another example, instead of performing the above pre-deoxidation by C, a method was also attempted in which Si and Mn were first added to perform a primary finish deoxidation treatment, and then Al was added to perform a second finish deoxidation treatment. The alloy ingot produced through such a treatment was hot forged, and then subjected to hot rolling and cold rolling to obtain a product having a thickness of 0.35 mm. Then, perform magnetic annealing for 110
The test was performed at 0 ° C. × 3 hours in a hydrogen atmosphere. The DC magnetization characteristics of this product were examined.

The DC magnetization characteristics are based on JIS C2531,
The primary and secondary sides of a 45 mm x 33 mm ring test piece are wound for 50 turns, and the saturation magnetic flux density is measured under the condition of a magnetic field of 1590 [A / m], and the maximum permeability, initial permeability and coercive force. For PC and 4 [A / m], the switching field was measured, and for PB and PD, 16 [A / m] was measured as the switching field.
The chemical composition was determined by X-ray fluorescence analysis.
Analyzed by DS (energy dispersive analyzer). PC, P
Examples corresponding to B and PD are shown in Tables 1, 2 and 3, respectively.

[0028]

[Table 1]

[0029]

[Table 2]

[0030]

[Table 3]

As is evident from Tables 1 to 3, in each of the examples of the present invention, the oxygen concentration was controlled to 50 ppm or less and the nonmetallic inclusions of alumina, magnesia, and spinel were all controlled. Since it is controlled to any one, it shows a value excellent in DC magnetization characteristics. Moreover,
It was found that, in the charge in which C was added and the preliminary deoxidation was performed under reduced pressure, the oxygen concentration was particularly low, and further excellent characteristics were exhibited.

On the other hand, in the comparative example, since the Al concentration was low, the oxygen concentration was high, and the inclusion composition was a silicate-based material which had a relatively low melting point and was easily stretched and dispersed in the forging and hot rolling processes. It was found that the value of the DC magnetization characteristics was inferior.

[0033]

As described above, according to the present invention,
"Magnesia, alumina, and spinel," which can reduce the oxygen concentration that forms nonmetallic inclusions in Fe-Ni-based permalloy alloys and that does not elongate the chemical components of the nonmetallic inclusions during the hot rolling process ”, The magnetic characteristics can be significantly improved.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C21C 7/00 C21C 7/00 C 7/04 7/04 B H01F 1/147 C22C 19/03 E // C22C 19 / 03 38/00 303S 38/00 303 H01F 1/14 A (72) Inventor Tatsuya Ito 4-2 Kojimacho, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture, Japan Nihon Metallurgical Industry Co., Ltd. (72) Inventor Akinori Katsumata Kanagawa 4-2, Kojima-cho, Kawasaki-ku, Kawasaki-ku, Japan F-term in the Technical Research Laboratory of Nihon Metallurgical Industry Co., Ltd. 4K013 AA01 AA04 BA08 CD04 CE06 CF12 CF19 DA03 DA09 DA12 DA14 EA19 EA20 EA28 EA30 FA02 FA04 5E041 AA07 CA01 HB08 NN17

Claims (7)

[Claims] In the production of a Fe-Ni permalloy containing 30 to 85 wt% of Ni, the oxygen concentration in the atmosphere in the melting vessel is controlled to 0.1 vol% or less when deoxidizing treatment is performed.
A primary deoxidation treatment is performed in which deoxidation is performed by adding a deoxidizing agent consisting of i and / or Mn, and thereafter, Al or an Al-containing deoxidizing agent is further added to the alloy melt in the container, and oxygen in the alloy melt is added. Perform a secondary deoxidation treatment to control the concentration to 50 ppm or less,
A method for producing a Fe-Ni-based permalloy, comprising: 2. The method according to claim 1, wherein the oxygen concentration of the molten alloy after the primary deoxidizing treatment is set to 100 ppm or less. 3. In the production of a Fe-Ni-based permalloy containing 30 to 85% by weight of Ni, when performing a deoxidation treatment, first, the alloy melt in the melting vessel is preliminarily deoxidized, and then a final deoxidation treatment is performed. The oxygen concentration in the molten alloy is controlled by controlling the oxygen concentration in the atmosphere in the melting vessel to 0.1 vol% or less and adding a deoxidizing agent made of Si and / or Mn to deoxidize the molten metal.
Perform a primary deoxidation treatment to 100 ppm or less, and then further
A secondary deoxidation treatment in which Al or an Al-containing deoxidizing agent is added to the alloy melt in the container to control the oxygen concentration in the alloy melt to 50 ppm or less, characterized in that the Fe-Ni-based permalloy alloy Production method. 4. The method according to claim 3, wherein the pre-deoxidation treatment is performed by reducing the atmosphere in the melting vessel to 5 torr or less.
Alternatively, by adding a C-containing deoxidizing agent, the oxygen concentration in the molten alloy is reduced to 200 ppm or less Fe-N
Manufacturing method of i-based permalloy. 5. The Fe—Ni-based permalloy produced by the method according to claim 1 contains 30 to 85% by weight of Ni, and is further selected from Mo, Cu, Co and Nb. One or more elements, each containing up to 15 wt% and a total of up to 20 wt%, with the balance Fe
A method for producing an Fe-Ni-based permalloy, characterized in that: 6. The method according to claim 1, wherein
A high-frequency induction furnace is used as the melting vessel, and the inner wall refractory of the melting vessel is made of any one of magnesia, alumina, and spinel.
Method of producing permalloy alloy. 7. The method according to any one of claims 1 to 6, wherein the alloy produced by these methods comprises Ni.
Those containing 30 to 40 wt% have a maximum magnetic permeability μm of 30,000 or more, an initial magnetic permeability μi of 10,000 or more, and a coercive force Hc of 7.0 [A / m].
Those exhibiting the following magnetic characteristics and containing 40 to 50% by weight of Ni have a maximum magnetic permeability μm of 70,000 or more and an initial magnetic permeability μi of 10,000.
As described above, the magnetic properties of the coercive force Hc = 5.0 [A / m] or less were exhibited.
Contains 70 to 85 wt%, the maximum permeability μm = 300,000
As described above, the initial permeability μi = 200,000 or more, and the coercive force Hc = 0.7 [A /
m] A method for producing a Fe—Ni-based permalloy having the following magnetic properties: