JP2003213374A - Iron-manganese nonmagnetic alloy - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a material which has properties such as spring properties, workability, rigidity, resistance to repeated bending and corrosion resistance so as to order the shape of underwear such as brassieres and corsets, or suitable for the accessories of wear such as hooks and grippers, and has no magnetism even by intensive working so that it does not become an obstacle to search for a broken needle, and further can be produced at a low cost. <P>SOLUTION: The iron-manganese nonmagnetic alloy having excellent workability and spring properties has a composition containing, by weight, ≤0.3% C, ≤0.2% N and 30 to 45% Mn, and the balance Fe with inevitable impurities. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an iron-manganese non-magnetic alloy excellent in workability and spring, and more particularly to an iron-manganese non-magnetic alloy suitable for use in clothes such as underwear of brassieres and the like.

[0002]

2. Description of the Related Art Conventionally, a spring-like metal has been used for underwear such as brassieres and corsets or accessories such as hooks and grippers. The required properties of such a metal are, of course, springiness and workability, but also some rigidity, resistance to repeated bending, and corrosion resistance. Recently, shape memory alloys such as Ni—Ti alloys have been developed as materials having such characteristics and are used in brassieres and the like. However, because they are difficult to process and expensive, they are partially used as high-grade products. Only. For this reason, the conventional magnetic piano wire or the like is often used.

Needless to say, it is necessary to sew clothes such as underwear, but needles may break during the sewing process. In particular, since underwear is in direct contact with the body, if a needle remains inside such clothes, it may cause a serious accident. Generally, the magnetic exploration method is an effective means for searching for such a broken needle. However, when magnetic metals are embedded inside clothes as described above, the magnetism interferes with the problem that the broken needle cannot be searched.

For this reason, instead of the above-mentioned piano wire, non-magnetic SUS304 or higher-grade SUS316L is used.
The use of such austenitic stainless steels has been studied. However, when such stainless steel is subjected to severe working for forming for several times, work-induced transformation occurs, ferromagnetic martensite is generated, and magnetic probing operates. In addition, aluminum alloys and copper alloys are also available as non-magnetic materials, but there is a problem in that sufficient spring properties cannot be retained. Thus, on the one hand, properties such as springiness suitable for adjusting the shape of underwear such as brassieres and corsets or used as accessories for other clothing are strongly demanded, and on the other hand, cost reduction is required. Moreover, there is a need for a material that does not have magnetism even by strong working. However, at present, a steel material or an inexpensive alloy suitable for such a material has not been found.

[0005]

[Problems to be Solved by the Invention] The underwear such as a brassiere or corset is shaped, or spring characteristics, workability, rigidity, resistance to repeated bending, corrosion resistance, etc. suitable for clothing accessories such as hooks and grippers are provided. An object of the present invention is to provide a material that has a magnetic property that does not have magnetism even by strong processing so as not to interfere with the exploration of a broken needle and the like and that can be manufactured at low cost.

[0006]

The present inventors have improved the iron-manganese-based material to obtain the above-mentioned properties such as spring property and workability, and at the same time, have no magnetism even by strong working. We obtained the knowledge that Based on this finding, the present invention provides: C: 0.3 wt% or less, N: 0.2 wt% or less, M
1. Iron-manganese nonmagnetic alloy excellent in workability and spring, characterized in that n: 30 to 45 wt%, balance Fe and inevitable impurities 2. 2. The iron-manganese non-magnetic alloy as described in 1 above, which is for clothes such as underwear. The iron-manganese non-magnetic alloy gold according to the above item 2, which is used for a brassiere.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As a conventional iron-manganese-based (manganese-based austenite) material, there is hadfield steel known from old times. This hadfield steel is 11
~ 14wt% Mn, 0.9-1.3wt% C, balance Fe
It is an alloy steel consisting of and is a completely austenitic material. However, since the austenite of this alloy steel is unstable, it undergoes martensitic transformation and work hardening instantaneously when an impact is applied. Therefore, the Hadfield steel itself utilizes such a work-hardening property and does not have characteristics as a non-magnetic material. In addition to hadfield steel, many manganese-based non-magnetic steels have been developed. Some of these non-magnetic steels have a magnetic permeability of 1.001 to 1.002 in a completely austenitic structure formed by casting or quenching after working. However, these non-magnetic manganese-based materials have a manganese content of 25 wt% or less, and are slightly magnetized due to cold-working of several tens of percent or more.
To prevent this, it is usual to add several percent or more of nickel. In addition, Fe-22Mn-13Cr-5Ni and Fe-22Mn- with chromium and molybdenum added to further increase the strength
There are alloy steels such as 13Cr-7Ni-1Mo, which are non-magnetic materials that do not become magnetic even when processed, and are therefore used as materials for nuclear fusion devices and superconducting linear structures.

However, the above-mentioned additive elements nickel, chromium, molybdenum, etc. have a drawback that the cost of the manganese-based material is significantly increased. Therefore, the present invention increases the amount of manganese in order to stabilize the austenite phase, and by adding N and C which are the austenite stabilizing elements, it is possible to make them non-magnetic and to provide a suitable spring property. The material that can be obtained is manufactured inexpensively. Mn amount is 30 to 45 wt
%. If it is less than 30 wt%, it will be magnetized after processing such as rolling, and if it exceeds 45 wt%, processing will be difficult.
It is preferable to set it to 30 to 45 wt%. Especially, the Mn amount is 32
It is desirable to set it to ˜38 wt%. C is an austenite stabilizing element, and the added amount is 0.3 wt% or less.
This is because if it exceeds 0.3 wt%, manganese carbide and iron carbide are generated and the material becomes hard, which makes processing difficult. In the iron-manganese non-magnetic alloy of the present invention, adjustment of this C content is particularly important. However, if the content is up to 0.3 wt%, the rolled surface becomes clean and the magnetism is not affected, so the content is 0.3 wt% or less, preferably 0.
It can be contained in the range of 25 wt% or less. Further, N is added in an amount of 0.2 wt% or less. N is a very strong austenite stabilizing element. However, if it is contained in a large amount, many pinholes are generated, so the above range is set.

In addition, in order to improve strength, corrosion resistance and cold workability, Si, Cr, Ni, Mo, Nb, Ti,
0.1 to 4.0 wt% of any one or more of Zr
It can also be added in the range of%. The balance is Fe and inevitable impurities. The iron-manganese non-magnetic alloy of the present invention is excellent in workability and spring even though it is an alloy having a simple composition as described above, and is a material that does not have magnetism even by strong working, and is low in cost. It has an excellent feature that it can be manufactured by. From the above, it is most suitable as a material used for clothes such as underwear such as brassieres and corsets, and other accessories for clothes, and can easily perform magnetic exploration for detecting broken needles when sewing clothes. There is an advantage.

As the method for producing the alloy of the present invention, C: 0.
3 wt% or less, N: 0.2 wt% or less, Mn: 30 to 4
After adjusting appropriate raw material components within a composition range of 5 wt% and the balance of Fe, the materials are melted by using an arc melting furnace or a high frequency melting furnace, which is used as a casting ingot and further forged,
It is manufactured through processing steps such as rolling. The rolled plate is further heated in air at 300 to 500 ° C. for about 10 minutes to 1 hour,
Quench in water to give it springiness. Fine wire processing is performed as necessary. The material thus obtained is manganese,
Due to the interaction of nitrogen and carbon, austenite has the advantages of being extremely stable, having low magnetic permeability and non-magnetism, and having excellent strength and spring properties. Therefore, it can be used not only for clothes as described above, but also for structures used in a strong magnetic field such as guideways of linear motor cars, etc., and can be used for cryogenic structures because there is no risk of cracking even at extremely low temperatures. It has an excellent feature that it can be done.

[0011]

EXAMPLES AND COMPARATIVE EXAMPLES Next, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. That is,
Of course, other examples, modes, modifications and the like within the scope of the technical idea of the present invention are included.

(Example 1) Mn 35.4 wt%, C0.
Iron alloy 2 which is 06 wt%, N 0.11 wt% and balance iron
High frequency melting of 00g and 2kg. The magnetic permeability of this iron alloy in the as-cast state was 1.001. This ingot was processed by cold rolling with a processing rate of 80% to a plate thickness of 1 mm. By this processing, a thin plate without cracks was obtained. The magnetic permeability of this thin plate was 1.002, and it did not react even when contacted with a needle finder (magnetometer). When this thin plate was bent by a bending test, it fractured at 150 °. That is, it is easy to break in the rolled state. But,
When this was heated in air at 400 ° C for 15 minutes and cooled with water, bending at 180 ° C was possible. Furthermore, when this was processed into a coil, excellent spring properties were obtained. There was no difference between the iron alloy dissolution amount of 200 g and 2 kg, and similar results were obtained. Further, the above-mentioned properties such as non-magnetic property, spring property, and workability are the same in the composition range of C: 0.3 wt% or less, N: 0.2 wt% or less, Mn: 30 to 45 wt%, and the balance Fe. The result was obtained.

(Comparative Example 1) Mn 25 wt%, C0.05
High-frequency melting was performed with 200% by weight of the iron alloy having the balance of iron. The magnetic permeability of this iron alloy in the as-cast state is 1.001.
Met. This ingot was processed by cold rolling with a processing rate of 80% to a plate thickness of 1 mm. By this processing,
The permeability of this sheet increased to 1.2 and the needle finder (magnetometer) reacted. The magnetic properties of this material after rolling are about the same as those of SUS316L after rolling.

(Comparative Example 2) Mn 25 wt%, C0.4 w
200% of an iron alloy containing t% and the balance of iron was subjected to high frequency melting.
Since this ingot cracks during cold rolling, thin plate processing could not be performed. Moreover, when N0.4 wt% was added to this alloy, the ingot became porous due to undissolved nitrogen gas, and it could not be made into a product.

[0015]

The iron-manganese-based nonmagnetic alloy of the present invention is
It is a material that is easy to manufacture and has properties such as spring properties, workability, rigidity, resistance to repeated bending, corrosion resistance, and a low coefficient of thermal expansion. It has an excellent feature that it can be manufactured by. The iron-manganese-based non-magnetic alloy having such characteristics is particularly suitable for adjusting the shape of underwear such as brassieres and corsets, and other clothing accessories or structures used in high magnetic fields or low temperature structures. It has an excellent effect that it can be used for. Further, when it is used for the above-mentioned clothes and the like, there is a remarkable advantage that it does not hinder the magnetic exploration of the broken needle during sewing.

Claims (3)

[Claims] 1. C: 0.3 wt% or less, N: 0.2 wt
%, Mn: 30 to 45 wt%, balance Fe and unavoidable impurities, and is an iron-manganese non-magnetic alloy excellent in workability and spring. 2. The iron-manganese non-magnetic alloy according to claim 1, which is for clothes such as underwear. 3. The iron-manganese non-magnetic alloy according to claim 2, which is used for brassieres.