JPS6240344A - Fe-co alloy having high magnetic permeability - Google Patents

Abstract

PURPOSE:To obtain a magnetic alloy having superior reversible magnetic permeability by adding specified amounts of C and W to 2V Permendur as an alloy having high magnetic permeability. CONSTITUTION:An alloy consisting of 40-55% Co, 0.5-2.5% V, 0.01-0.05% C, 0.1-3% W and the balance Fe is manufactured by adding C and W to 2V Permendur consisting of 2% V, 49% Co and the balance Fe and having high saturation magnetic flux density as a magnetic material for the diaphragm of a telephone or a speaker. The alloy is cast, cogged and hot rolled to obtain a plate of 3mm thickness. This hot rolled plate is heated to 1,000 deg.C for 0.5hr, quenched in water, descaled and cold rolled. The resulting cold rolled thin plate of 0.3mm thickness is annealed at 800 deg.C for 3hr and subjected to furnace cooling. Thus, an Fe-Co alloy plate having high magnetic permeability and superior reversible magnetic permeability is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a Fe--Co based high magnetic permeability alloy useful as a magnetic pole material for diaphragms of telephones and speakers.

[Conventional technology]

Fe--Co alloy has the highest saturation magnetic flux density among all materials.

Fe-Co binary alloy is very easy to order and brittle, so
Materials whose toughness is improved by adding V, Cr, Nb, etc. as a third element are currently in practical use. Generally, 2V-49Go-Fe containing about 2% of V is a typical alloy, and is known as Vermender.

The Fe-Co alloy used as a high magnetic permeability material has a single ferrite phase, and is usually subjected to heat treatment conditions that increase the grain size, such as (75o-900) 'Cx (2-4)H furnace cooling, and then It is incorporated into parts.

In the case of soft magnetic ferrite alloys, the content of interstitial solid solution atoms is controlled to be low because they degrade magnetic permeability. And in 2v-permender, JP-A-47-9
05, C content is usually 0.01% as shown in P2
It is reported that:

In order to obtain high reversible magnetic permeability (μr) under a high magnetic field, the present invention added various additive elements to 2v-permender and tested it.
This is based on the discovery that high reversible magnetic permeability (μr) was obtained when the content was 0.1-3%.

[Problem that the invention seeks to solve]

Conventional 2V-Permender has a reversible magnetic permeability (μr) of about 1000 at shoulder wave number IKHz when used in a high magnetic field such as the diaphragm of a telephone receiver, and has the disadvantage that it cannot increase sensitivity when made smaller. there were.

In order to solve the above-mentioned drawbacks, the present invention provides an alloy with high reversible magnetic permeability (ur) by optimizing the alloy composition.

[Means for solving problems]

The present invention has 1 weight ratio of Co 40-55%, V 0.5~
2.5-2.5%, W 0.5-2.1-3%, G
0.5-2.01-0.05% and the balance substantially Fe
It is a magnetic alloy with high reversible permeability (ur).

Co and V are the main elements that make up Permender, and Co increases the magnetic flux density by forming an alloy with Fe.
If it is less than 40% or more than 55%, the magnetic permeability decreases, so it is set to 40 to 55%.

V is known as an element that improves the workability of Fa-Co alloys. If it is less than 0.5%, it has no effect on improving workability;
．． If it exceeds 5%, the magnetic permeability of the Permender alloy decreases, so it is set at 0.5 to 2.5%.

W and C are the reversible magnetic permeability (ur) of the 2v-permender alloy
This effect was discovered during research to increase the 2
The coercive force Hc of V-permender alloy is approximately 0.5 (Os
), but the reversible permeability (ur) shows a small value when the plate thickness is 0.
3m, magnetic flux density B = 15-18 (KG), frequency f
= exhibits a value of about 900 at IKHz. However, this
When W and C are added as in the invention, the coercive force is 0.7 to 1
．． 5 (Os), and generally exhibits an effect of deteriorating soft magnetism. However, the reversible permeability (ur) is 10
This mechanism is unknown, but B-H
On the curve, the residual magnetic flux density Br decreases slightly and the shoulder of the first curve becomes smooth. This is probably due to the action of solid solution carbon and W carbide.

In the present invention, C is set to 0.01 to 0.05% because 0.0
When it is less than 1%, ur is small, and when it is 0.5 to 2. This is because if it exceeds OS%, the coercive force increases and the characteristics of a soft magnetic material are lost.

It shows similar results to W+JC, and ur is small at 0.1%, and coercive force becomes large when it exceeds 3mm.
%.

Further, in the present invention, even when SL, Mn, and A1 were contained as deoxidizing agents in an amount of 0.5z or less, no change was observed in the characteristic of high reversible magnetic permeability (ur).

〔Example〕

After melting 7 kg of the alloy whose chemical composition is shown in Table 1 in a high-frequency vacuum induction melting furnace, a plate material having a thickness of 3 mm and a width of 80+ m was manufactured by casting → decomposition → hot rolling.

After rolling the first plate, it was heated at 1000°C for 0.5 hours, rapidly cooled in water, the first surface scale was removed, and the plate was cold rolled to a thickness of 0.
I finished it in 3■. A 33φ x 45φ JIS ring was taken from this material, heat treated at 800°C and cooled in a furnace for 3 hours, and then the reversible magnetic permeability (ur) was determined by applying a bias magnetic field with DC magnetic properties and magnetic flux density B = 15 (KG).
(f=IK7) was measured.

As is known from the results in Table 1, the present alloy has a slightly inferior coercive force HC compared to the conventional 2v-Vermender alloy, but its reversible magnetic permeability (ur) has increased considerably.

〔Effect of the invention〕

As is clear from the above, the alloy of the present invention has a higher reversible magnetic permeability (UR) than the conventional 2V-bermender, and is suitable for increasing the sensitivity of magnetic poles and diaphragms of telephone receivers, and is suitable for industrial use. is considered to be very beneficial.

Claims (1)

[Claims] Co 40-55%, V 0.5-2.5% by weight
, 0.1 to 3% of W, 0.01 to 0.05% of C, and the balance substantially composed of Fe, and is characterized by having a high reversible magnetic permeability.