JPH0245697B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is based on HADFIELD'S AUSTENITIC
This invention relates to improvements in the Fe-Mn-C alloy known under the name STEEL. HADFIELD'S AUSTENITIC
STEEL is an alloy with a composition consisting of appropriate amounts of Mn and C with the balance being iron, and it is possible to easily introduce the austenite phase (hereinafter referred to as γ phase) of a non-magnetic material at room temperature, and it is possible to easily introduce martenite phase (hereinafter referred to as γ phase) at room temperature. It is a material in which site transformation (γ phase → martensitic phase (hereinafter referred to as α phase) hardly occurs. Also,
When the above-mentioned alloy is subjected to cold working in the γ phase state, it is significantly work hardened and its mechanical strength increases. However, when an attempt is made to form an α phase, which is a ferromagnetic phase, in a γ phase matrix by heat treatment, the γ phase is stable at low temperatures, so the γ→α transformation does not occur easily even after heat treatment, and the γ→ A long heat treatment is required to complete the α transformation. The reason why the long heat treatment is required is that appropriate amounts of Mn and C are added, and the effect of C is particularly large. This alloy has α+γ+Fe ₃ C or γ+Fe ₃ C between the α and γ phases.
A mixed phase of Fe 3 C is formed, and Fe ₃ C is strongly bound.

As described above, this alloy has the advantage that the γ phase can be easily introduced at room temperature, but when considering its application to magnetic materials, it has the disadvantage of requiring a long heat treatment for the γ→α transformation.

The present invention provides a composite magnetic material characterized in that Zr is added to the above-mentioned conventional alloy in order to easily transform the γ-phase of the above-mentioned alloy introduced into room temperature into the α-phase by subjecting it to short-time heat treatment. The present invention relates to alloys, and aims to provide an alloy for composite magnetic materials that is industrially effective, has a wide range of applications, and is excellent in terms of productivity by taking advantage of the advantages of the above-mentioned alloys and solving the above-mentioned drawbacks.

According to the alloy for composite magnetic materials of the present invention, by annealing the material using a laser beam, an electron beam, an infrared beam, etc., the surface of the non-magnetic material can be formed at an arbitrary depth and in an arbitrary pattern. It became possible to form a magnetic phase.

Furthermore, compared to a composite magnetic material that is made by joining a non-magnetic material and a magnetic material together using an adhesive, mechanical method, thermocompression bonding, etc., the composite magnetic material manufactured by the method of the present invention has a mechanical It was also found to be superior in terms of reliability.

The reason for limiting the range of chemical components of the alloy for composite magnetic material in the present invention will be described below.

Fe is the main component of the alloy for composite magnetic material in the present invention. The γ phase of Fe is unstable and transforms into the α phase during the cooling process, no matter how quickly it is cooled.

The γ phase of Fe contains up to about 2% by weight of C as a solid solution and γ-
However, when rapidly cooled from high temperature, γ
In order to bring the phase to room temperature, more than 2% by weight of
Mn had to be added. On the other hand, in order to obtain an alloy with a practically sufficient amount of magnetization,
Mn must not be added in excess of 20% by weight, and the maximum
When 20% by weight of Mn was added, the γ phase could be easily introduced at room temperature by adding 0.4% by weight or more of C. If more than 2% by weight of C is added, all the added C will not be solidly dissolved and will be incorporated into the matrix of the γ phase.
A compound in which Mn, Zr, or Fe and C are bonded coexists, making it impossible to obtain a single γ phase at room temperature. Therefore, the alloy for composite magnetic materials of the present invention containing more than 2% by weight of C is difficult to cold-work such as rolling, wire drawing or swaging at room temperature.

The γ phase can be introduced to room temperature by rapidly cooling the alloy in the above composition range, but 0.1 to 2.0% by weight of Zr was added to facilitate the γ→α transformation. 0.1
If the amount added is less than 2.0% by weight, the effect of Zr addition is not exhibited, and if it is added in excess of 2.0% by weight, it becomes an α phase in the entire temperature range.

Next, the details of the present invention will be described by listing them in Examples.

Example 1 An alloy ingot having the composition (Fe _85.8 Mn ₁₃ C _1.2 ) _99.4 Zr _0.6 in weight % was heated at a temperature of 1100° C. for 1 hour.
After homogenization treatment in an Ar atmosphere, it was immersed in a 10% NaOH aqueous solution and rapidly cooled. When a small piece is cut out from this alloy ingot and the amount of magnetization is measured, σs=
It was a γ phase of 0.02 (emu/gm). After removing the surface oxide film, this alloy ingot has an area reduction rate of 50%.
When subjected to cold rolling processing, the amount of magnetization is σs=
It became 0.05 (emu/gm). Furthermore, when this alloy ingot was further cold-rolled with an area reduction rate of 99% from its initial shape, the amount of magnetization was reduced to σs = 0.1.
It became (emu/gm). Also, mechanical strength σa ₂ =
14BKg/mm ² Bits hardness Hv = 743.

A 50 μm thick γ-phase plate material cold-rolled as described above was annealed at 550° C. for 5 seconds in an Ar atmosphere, and then rapidly cooled in an Ar atmosphere. the result,
Magnetization amount σs = 131 (emu/gm). Mechanical strength σa ₂ = 92
(Kg/gm ² ) It became an α phase with a Bitkers hardness of Hv=518.

In addition, the surface of the γ phase plate material with a thickness of 50 μm was
1mm with 3W continuous wave YAG laser annealing equipment
A laser beam with a diameter of 1 mm/ses was run at a speed of 1 (mm/ses) to perform annealing and purification in an Ar atmosphere. When the heated part was observed under a microscope, it was confirmed that it had transformed into a phase different from the γ phase in a width of approximately 1.1 mm over the entire length in the thickness direction, and the phase-transformed part was cut out and the magnetization amount was determined. When measured, it was found to be an α phase with σs=121 (emu/gm).

Example 2 An alloy ingot having the composition (Fe ₉₆ Mn ₂ C _2.0 ) ₉₈ HZr _2.0 in weight % was heated at a temperature of 1100° C. for 1 hour.
After homogenization treatment in an Ar atmosphere, it was immersed in a 10% NaOH aqueous solution and rapidly cooled. Cutting out a small piece from this alloy ingot and measuring the amount of magnetization, σs = 0.03
(emu/gm). After removing the surface oxide film of this alloy ingot, it was cold rolled with an area reduction rate of 99%, and the magnetization amount σs = 0.3
It became (emu/gm). Also, mechanical strength σ _0.2 =
The hardness was 137Kg/mm ² and the Bitkers hardness Hv was 653.

A 50 μm thick γ-phase plate material cold-rolled as described above was rapidly cooled at 600° C. for 5 seconds in an Ar atmosphere. As a result, the amount of magnetization σs = 147 (emu/
gm) Mechanical strength σ _0.2 = 85 (Kg/mm ² ) and Vickers hardness Hv = 50.

In addition, the surface of the γ phase plate material with a thickness of 50 μm was
1 with 3.5W continuous wave YAG laser annealing equipment
A laser beam with a diameter of mm was run at a speed of 1.5 (mm/ses) to perform annealing and purification in an Ar atmosphere. When the heated part was observed under a microscope, it was confirmed that it had transformed into a phase different from the γ phase in a width of approximately 1.1 mm over the entire length in the thickness direction, and this phase-transformed part was cut out and magnetized. When the amount was measured, σs = 136 (emu/
gm).

Example 3 An alloy ingot having a chemical composition of (Fe _79.6 Mn ₂₀ C _0.4 ) _99.9 Zr _0.1 in weight% was homogenized in an Ar atmosphere at a temperature of 1100°C for 1 hour, and then immersed in a 10% NaOH aqueous solution. and cooled quickly. Cutting out a small piece from this alloy ingot and measuring the amount of magnetization, σs = 0.03
(emu/gm). After removing the surface oxide film of this alloy ingot, it was cold rolled with an area reduction rate of 99%, and the magnetization amount σs = 0.2
It became (emu/gm). Also, mechanical strength σ _0.2 =
123 (Kg/mm ² ), and Bitkers hardness Hv=587.

A 50 μm thick γ-phase plate material cold-rolled as described above was sintered in an Ar atmosphere at a temperature of 500° C. for 5 seconds, and rapidly cooled in an Ar atmosphere.

As a result, magnetization amount σs = 115 (emu/gm), mechanical strength σ _0.2 = 79 (Kg/mm ² ), and Vickers hardness Hv = 491
It became the α phase of

In addition, the surface of the γ phase plate material with a thickness of 50 μm was
1 with 2.5W continuous wave YAG laser annealing equipment
Annealing was performed in an Ar atmosphere by running a mm diameter laser beam at a speed of 1 (mm/sec). When the heated part was observed under a microscope, it was confirmed that it had transformed into a phase different from the γ phase in a width of approximately 1.1 mm over the entire length in the thickness direction, and this phase-transformed part was cut out. When we measured the amount of magnetization, σs = 105 (emu/
gm).

Example 4 The alloy ingot used in Example 1 was homogenized at a temperature of 1100°C for 1 hour in an Ar atmosphere, and then 10%
It was quenched by immersing it in a NaOH aqueous solution. When a small piece was cut out from this alloy ingot and the amount of magnetization was measured, it was found to be a γ phase with σs = 0.02 (emu/gm). After removing the surface oxide film of this alloy ingot, it was cold-rolled with an area reduction of 99% to form a plate material with a thickness of 50 μm. This plate material was heat-treated at a temperature of 950° C. for 5 seconds in an Ar atmosphere, and then rapidly cooled in an Ar atmosphere. As a result, the magnetization amount σs = 0.02 (emu/gm), the mechanical strength σ _0.2 = 55 (Kg/mm ² ), and the Vickers hardness Hv = 275.

The above heat-treated 50 μm thick γ-phase plate material
Annealed in an Ar atmosphere at a temperature of 550℃ for 5 seconds.
It was quenched in an Ar atmosphere. As a result, the amount of magnetization σs=
117 (emu/gm), mechanical strength σ _0.2 = 71 (Kg/mm ² ),
It became an α phase with a Bitkers hardness of Hv=411.

In addition, the surface of the γ phase plate material with a thickness of 50 μm was
1mm with 3W continuous wave YAG laser annealing equipment
Annealing was performed in an Ar atmosphere by running a laser beam with a diameter of 1 (mm/ses) at a speed of 1 (mm/ses). When the heated part was observed under a microscope, it was confirmed that it had transformed into a phase different from the γ phase in a width of approximately 1 mm over the entire length in the thickness direction, and this phase-transformed part was cut out and the amount of magnetization was determined. When measured, α of σs = 109 (emu/gm)
It was a phase.

Example 5 An alloy ingot having the composition used in the example was heated to 1100°C.
After homogenization treatment in an Ar atmosphere at a temperature of 1 hour, the sample was quenched by immersion in a 10% NaOH aqueous solution. When a small piece was cut out from this alloy ingot and the amount of magnetization was measured, it was found to be a γ phase with σs = 0.02 (emu/gm). After removing the surface oxide film of this alloy ingot, it was cold rolled with an area reduction rate of 75%, and then
After homogenization treatment at a temperature of 950° C. for 30 minutes in an Ar atmosphere, it was immersed in the above solution and rapidly cooled. As a result, the magnetization amount is σs = 0.02 (emu/gm) as above
It was hot. Subsequently, cold rolling was performed again with an area reduction rate of 50% to obtain a plate material with a thickness of 30 μm.

As a result, magnetization amount σs = 0.05 (emu/gm), mechanical strength σ _0.2 = 128 (Kg/mm ² ), and Vickers hardness Hv =
It was 675.

The above cold-rolled plate material with a thickness of 30 μm is
Annealed in an Ar atmosphere at a temperature of 550℃ for 5 seconds,
It was quenched in an Ar atmosphere. As a result, the amount of magnetization σs=
It became an α phase with a mechanical strength of 128 (emu/gm), σ _0.2 = 89 (Kg/mm ² ), and a Vickers hardness, Hv = 513.

In addition, the surface of the γ phase plate material with a thickness of 30 μm was
1mm with 3W continuous wave YAG laser annealing equipment
Annealing was performed in an Ar atmosphere by running a laser beam with a diameter of 1 (mm/sec.) at a speed of 1 (mm/sec.). When the heated part was observed under a microscope, it was confirmed that it was transformed into a phase different from the γ phase in a width of approximately 1.1 mm over the entire length in the thickness direction, and the transformed part was cut out and the magnetization amount was determined. When measured, it was found to be an α phase with σs=119 (emu/gm).

(Fe _87.8 Mn ₁₀ C _2.2 ) _99.4 Zr _0.6 alloy with more than 2% C added was uniformly treated in an Ar atmosphere at a temperature of 1100°C for 1 hour, and then quenched by immersing it in a 10% NaOH aqueous solution. . As a result of X-ray measurement of this alloy,
The diffraction lines of the γ phase and other diffraction lines were measured. When this alloy was cold rolled, cracks appeared and rolling into thin sheets was impossible.

Although the above has been described based on the embodiments, it is possible to draw not only a linear magnetic pattern but also any complex magnetic pattern by moving the heating beam in any desired direction. In addition, when the opposite side of a 50 μm thick plate material was cooled and annealed with a laser beam in the same manner as in Example 1, no phase transformation occurred over the entire length in the thickness direction, and the cut surface was observed under a microscope. When observed, the depth of the portion transformed into a phase different from the γ phase (α phase) was approximately 20 μm.

It must be said that Fe--Mn--C alloys containing Zr have high industrial utility as alloys for composite magnetic materials because of their ease of heat treatment.

Claims (1)

[Claims] 1. An alloy for a composite magnetic material, characterized in that it contains 0.1 to 2 weight % of Zr in a composition consisting of 2 to 20 weight % Mn, 0.4 to 2 weight % C, and the balance Fe.