JPS6046341A - Magnetic alloy - Google Patents

Abstract

PURPOSE:To provide a magnetic alloy containing no expensive Mo at all and reduced in the content of expensive Ni without damaging the characteristics of a JIS-PC material, obtained by containing a specific amount of Cu and Cr in a Ni- Fe type alloy. CONSTITUTION:This alloy contains, on a wt. basis, 58-85% of Ni, 8-29% of Cu, 0.3-5% of Cr and the remainder of Fe as main components and further contains one or more of 0.01-3% Si, 0.05-1% of Zr, 0.1-0.8% of Ti, 0.1-5% of Nb, 0.1-5% of V and 0.1-5% W as auxiliary components and is excellent in corrosion resistance and good in magnetic characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high permeability magnetic alloy that has good magnetic properties and is applied to magnetic shield members etc. that require high magnetic permeability, and has improved corrosion resistance.

Magnetic shield members using Ni--Fe based high permeability alloys are widely used, for example, in shield cases for magnetic heads, magnetic shield plates for cassette tapes, and the like. M
High Ni/P-Malloy (JIS-PC material) containing o, Cu, etc. Oyohi Low Ni /<? -MaC1i (JIS-PB
materials) are often used. The former has high magnetic permeability and high corrosion resistance, but contains a large amount of expensive Ni at 76% by weight or more (hereinafter simply referred to as "M"), and is even more expensive.

Since it also contains , it has the disadvantage of being expensive among magnetic alloys. In addition, the latter has a Ni content of about 45%, so it is inexpensive and has a high saturation magnetic flux density BIO of 14,000 Gauss at 10 Oerste, but on the other hand, it has extremely poor corrosion resistance and has an initial magnetic permeability of 5.000 μm compared to the former. It has the disadvantage of being low.

Furthermore, this 45% Ni-Fe permalloy is magnetically/-
In order to use it as a shield member, it is necessary to perform a plating treatment as a rust prevention treatment, which is industrially disadvantageous.

Therefore, it is difficult to obtain a magnetic alloy that has excellent magnetic properties, high corrosion resistance, and is inexpensive using the conventional J I 5-PC material and PB, l. However, from an industrial perspective, there is a strong demand for inexpensive magnetic alloys that have excellent magnetic properties and corrosion resistance.

The present invention has been made in response to the above needs.

The object of the present invention is to provide a new magnetic alloy that does not contain any expensive Mo and has a reduced content of expensive Ni without impairing the characteristics of the JIS-PC material.

Research on Ni-Fe-Cu alloys, which are made by adding Cu to Ni-Fe alloys, has been conducted for a long time, and it is well known that they have excellent magnetic properties (for example, M
, “Ferromagnism” by Bozorth
”, D. van No5trandCo, 1951
). The present inventors have made various improvements to this Ni-Fe'Cu alloy (Japanese Patent Application No. 56-1976).
No. 17, Patent Application No. 1982-200045, Patent Application No. 58-4
．． No. 1498) was not necessarily perfect in terms of corrosion resistance. Therefore, after repeated experiments to perfect the corrosion resistance, it was found that the addition of Cr was effective in improving the corrosion resistance.
Si with r.

It has been found that the corrosion resistance is further improved when Zr, Tin Nb, V, and W are added in combination.

The present invention has been made based on the above considerations. That is, the alloy of the present invention contains 53 to 75% Ni and 8 to 2% Cu.
9q6. A magnetic alloy in which CrO3~5q6 balance is substantially Fe, and this alloy contains SiO, 01~3%,
Zr C1.05~1%, Ti 0.1~0.8%
, NbO, 1-5%, VO, 1-5%, W0
．． It is a magnetic alloy containing at least one or two or more of 1 to 5% + 7) in a total amount of 0.01 to 8.

Here, Ni has a high magnetic permeability in the range of 58 to 75 modulus, but if Ni is less than 58%, the magnetostriction increases and the permeability decreases, and if it exceeds 75%, the magnetic permeability decreases due to the addition of Cu amount of 8% or more. There is a significant decrease in Furthermore, those with N1 exceeding 75 units are industrially disadvantageous when resource saving and price reduction are taken into consideration.

Cu has high magnetic permeability within the range of 8 to 29 inches, but Cu
If the Cu content is less than 8 tib, high magnetic permeability cannot be obtained unless the Nl content exceeds 75 tib, and if the Cu content exceeds 29 tib, the initial permeability decreases and hot workability deteriorates.

Cr is added to improve the corrosion resistance of this alloy.If it is less than 0.3%, it will hardly improve the corrosion resistance, and if it is added in excess of 5%, the drawability will deteriorate, so the amount added is 0.3 to 5%. It is preferable to add 0.5% or more, and even more preferably 1% or more.

Si +Zr +Tj+Nb +V and W are both Cr
Corrosion resistance is improved by adding in combination with the above-mentioned amount.If the addition amount is less than the above-mentioned amount, the effect is not obvious, whereas if the addition amount exceeds the above-mentioned amount, the workability deteriorates.

Note that c and At are added to the alloy of the present invention as a deoxidizing agent and a desulfurizing agent.

Ca + Mg, Mn, etc. may be added in a total amount of 1 or less.

In particular, Mg is added as a desulfurization agent to improve hot workability, but the amount added is preferably 0.02% or less.

Next, an example will be described.

It was vacuum melted to have the composition shown in Table 1, thoroughly deoxidized with C, and desulfurized by adding Mg to reduce impurities as much as possible to obtain a uniform molten metal. This molten metal was poured into an appropriate mold and cooled at an appropriate cooling rate to prevent segregation of Cu to obtain a sound ingot. This ingot was subjected to conventional hot working and cold working to produce a plate material having a thickness of 0.5 mm. Here, no corner cracks, edge cracks, etc. occurred during hot working, and hot workability was good. Then, from these plates, a ring for measuring magnetic properties (
Outer diameter: 45 mm, inner diameter: 33 mm), corrosion resistance measurement sample (5 mm)
After magnetic annealing (1) of these samples in a hydrogen atmosphere (held at 0°C for 3 hours), the following items were investigated.

0 Magnetic properties: Initial magnetic permeability μm, saturation magnetic flux density B″□0 Coercive force Hc O Corrosion resistance: Salt spray test (JIS Z 2371) 1
The evaluation is based on the area ratio (A) of the 1θ filtered portion when continuously tested for 00 hours and 200 hours.

These results are shown in Table 1.

Table 1 shows that by adding Cr, the area ratio of corroded parts was less than 1% in the 9,100-hour salt water spray test.

It corroded by about 2 to 3 degrees in 200 hours. Also, Cr and si,
The composite addition of Zr+Ti, Nb+V, and W only corroded about 2% even after 200 hours.

As mentioned above (Ni-Fe-Cu alloy with Cr added and Cr and Sit Zrl Ti, Nb, v
, W is added in a composite manner, and the alloy has excellent corrosion resistance and good magnetic properties. Therefore, this alloy is suitable for use in, for example, the shield case of a magnetic head and the magnetic shield plate of a cassette tape.

Claims (1)

[Claims] 19% by weight, Ni 58-75%, Cu 8-29%
. A magnetic alloy consisting of 0.3 to 5 Cr and the remainder substantially Fe. 2% by weight N158-75%, Cu 8=29%
. Cr0.3-5%, balance Fe as main component, 81001-3% as secondary components, Zr 0.05-1%, T
i O, 1~08%, Nb0.1~5%, V0.1~5
%, W0.1-8 in total of one or more types from section 5
A magnetic alloy characterized by containing CH.