JPS60135545A - Free-cutting magnetic alloy - Google Patents

Abstract

PURPOSE:To obtain the titled alloy having improved machinability without deteriorating the hot workability by adding a specified amount of rare earth elements to an alloy having a specified composition consisting of Ni, Cu, Ti, Zr, V, Nb, Ta, Cr, Mo, W, Mn, Ge and Fe. CONSTITUTION:The machinability of an Ni-Fe-Cu alloy contg. much Cu is improved without deteriorating the hot workability or reducing the initial permeability by adding 0.001-0.5wt% rare earth elements to the alloy consisting of 57-74wt% Ni, 12-32wt% Cu, <=10wt% at least one among Ti, Zr, V, Nb, Ta, Cr, Mo, W, Mn and Ge, and the balance Fe to obtain a free-cutting magnetic alloy. Misch metal may be used as the rare earth elements, and it improves the machinability without deteriorating the hot workability by improving the crushability of shavings when added by above restricted amount.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a Ni-Fe-Cu alloy, namely (:'
This invention relates to a free-cutting magnetic alloy that has improved machinability such as machinability and punchability of uzf-malloy.

Traditionally, cylindrical malloy has been widely used as a material for electromagnetic equipment and magnetic shielding. For shielding purposes, it is widely used as magnetic herad shield cases and shield covers in the audio and VTR fields. For these applications, machines equivalent to JIS-PC, which is a high Ni permalloy that can obtain particularly high magnetic permeability among permalloy types, are mainly used, but since the price is relatively high, lowering the price is not desirable industrially. It is rare. Therefore, the Cuaj-Mai, which has an expensive Ni content of about 7 to 70% less than the conventional JIS-PC equivalent machine, has been attracting attention in recent years.

The basic composition of this CuA-malloy is 57 to 74% Ni and 2 to 34% Cu I in weight percent (hereinafter simply referred to as %).

It is the remainder of Fe and contains a large amount of Cu. For this reason, it is more flexible and sticky than conventional JIS-PC equivalent machines, resulting in poor machinability and shortened tool life. In particular, the magnetic shield case of the VTR audio control head has several holes for fixing screws.9. Furthermore, the hole is tapped. Therefore, when using Cu permalloy for the above purposes,
It is necessary to improve free machinability.

Generally, in order to improve the free machinability of Ni-Fe based magnetic alloys, a low melting point element that does not form a solid solution with the Nr-Fe based alloy is added to disperse it as fine metal particles in the alloy and improve the machinability. Further, a method of improving machinability by incorporating a large amount of impurities or nonmetallic inclusions into the alloy has been considered. but.

In the former method, the hot workability is significantly deteriorated and the magnetic permeability is reduced, and in the latter method, the magnetic permeability is also reduced.

The present invention has been developed using Ni-Fe-Cu containing a large amount of Cu'i without impairing hot workability or reducing initial permeability.
The purpose of the present invention is to provide a magnetic alloy with improved machinability.

The present invention contains Ni57-74%, Cu]2-32%
.

10% or less Ti, Zr + V, Nb,
By adding 0.001 to 0.5% of rare earth elements to an alloy consisting of at least one selected from Ta, Cr + Mo + W, Mn, Ge and the balance Fe, it is possible to improve hot workability and magnetic properties without impairing them. It has improved rigidity.

Next, the reason for limiting the alloy composition will be explained.

Although Ni has high magnetic permeability in the range of 57-74%.

When the N content is less than 157%, the magnetic permeability decreases and the corrosion resistance is also significantly inferior, and when the content exceeds 74 mm, the magnetic permeability decreases significantly due to the addition of Cu in an amount of 12% or more. Further, those containing more than 74% Ni are industrially disadvantageous in terms of saving resources and lowering prices.

Cu l has high magnetic permeability in the range of 2 to 32 cm, but Cu
If it is less than 12%, the Ni content must not exceed 74%.

If high magnetic permeability cannot be obtained and Cu exceeds 32%, the initial magnetic permeability decreases and hot workability deteriorates even if Ni is less than 57%.

In order to obtain high magnetic permeability within the above composition range for both Ni and Cu, the amount of Cu needs to increase as the amount of Ni decreases.

Ti, Zr + V, Nb + Ta, C
r, Mo, W, Mn.

Ge is added as a total upper limit of 10% to improve magnetic properties and mechanical properties. The preferable addition range of each additive element is + Ta + W + Mn is 10 each.
% or less + V + Nb + Cr + Mo + G
e is 6 tres or less, Ti 2% or less, Zr]
% or less. If these elements are added in excess of the above range, hot workability will deteriorate, saturation magnetic flux density will decrease, and machinability will also deteriorate.

Rare earth elements are elements added to improve machinability and have the effect of improving chip breakability.

If it is less than 0,001%, the effect of its addition is not obvious.

Addition of more than 0.5% K does not significantly improve machinability, and furthermore, hot workability deteriorates significantly. Here, the rare earth elements include 15 element elements from the 57th element La to the 71st element Lu in the periodic table. In the following examples, 9
A misch metal (M-M,) containing 8 rare earth elements and 40% or more of CeJ:Sfx was used.

Next, the present invention will be explained with reference to examples.

An alloy having the chemical composition shown in Table 1 was vacuum melted and then cast to obtain an ingot. These ingots are 900-1
A plate-shaped sample with a thickness of 6 mm was obtained by hot forging and hot rolling at an appropriate temperature range of 250°C.

At this time, hot workability was good in all cases. A 50x50x6 test piece was cut out from these samples and heated at 900°C.
It was annealed for 1 hour (in a hydrogen atmosphere) and subjected to a stiffness test. Further, the plate-shaped sample was cold-rolled to a thickness of 0.5 mm, with 10 outer diameters and 6 inner diameters.
A ring-shaped sample of the throat was punched out, annealed at 1100°C for 3 hours (in a hydrogen atmosphere), and the magnetic properties were measured.

Margin below (6) Table 1 Drilling was performed for each alloy shown in Table 1, and the cutting resistance at this time was measured. Cutting resistance was measured separately into torque and thrust components using a tool dynamometer. Furthermore, the total cutting torque during tapping was also measured. The cutting conditions at this time are summarized in Table 2, and the full measurement results Table 4
Shown below.

In addition, the measurement items of magnetic properties are shown in Table 3, and the measurement results are shown in Table 4.
Shown below.

Margin Table-2 Cutting Condition Table-3 Measurement Items (Note) Based on the Electronic Materials Industry Association standard EMAS-2003.

(9) Table-4 (10) Next, Al,! 3 and A9, the relationship between feed rate and cutting resistance during drilling is shown in Figs. 1 and 2. Figure 1 shows the results for the torque component, and Figure 2 shows the results for the thrust component. From these figures, it can be seen that the torque component and the thrust component of the alloy flat plate 9 of the present invention are smaller than those of the comparative flat sheets 1 and 3 of 1flJ, that is, the cutting resistance is smaller.

Furthermore, the total cutting torque during tapping for the same alloy is shown in FIG. This figure also shows that the alloy flat plate 9 of the present invention has a smaller cutting resistance than the flat plates 1 and 3 of the comparative example.

” As shown in Example 2, in the alloy of the present invention, N
A preferable composition range from the viewpoint of magnetic properties is 60 to 69% for i and 16 to 30% for Cu.

- As mentioned, N157~74%, Cu ] 2~
32%, 10% or less of 'ri, Zr, V,
Nb + Ta, Cr.

It consists of at least one selected from Mo + W + Mn + Ge and the remainder Fe. The so-called CuzR-
Malloy contains rare earth elements i0. By containing oo1-05chi, it is possible to improve machinability without impairing hot workability and magnetic properties. Therefore, the alloy of the present invention has VT
It is extremely useful as a magnetic nozzle case for R, and is also useful as a material for various electromagnetic devices used in other cutting processes.

[Brief explanation of drawings]

FIGS. 1 and 2 are diagrams showing the relationship between tool feed rate and cutting resistance during drilling, and FIG. 1 shows the torque component of the cutting resistance, and FIG. 2 shows the thrust component. FIG. 3 is a diagram showing the cutting torque for each material during tapping.

Claims (1)

[Claims] 1. Ni 57-74%, Cu 12-32% by weight,
10% or less T+ + Zr r V + Nb +
A free-cutting magnetic alloy characterized by containing 0.001 to 0.5% of a rare earth element in an alloy consisting of at least one selected from Ta + CryMo + W, Mn, and Ge and the remainder Fe.