JPH1025517A - Production of iron-nickel alloy sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control a texture so that low magnetostrictive characteristic required of a deflection yoke is obtained, by subjecting an ingot of an Fe-Ni alloy of specific composition to hot rolling, to cold rolling at specific draft, and then to annealing so that specific crystalline grain size is obtained. SOLUTION: An alloy, having a composition consisting of, by weight, 38-52% Ni, <=0.10% C, <=0.5% Si, 0.1-2.0% Mn, and the balance Fe with inevitable impurities, is cast. The resultant ingot is hot-rolled and then cold-rolled at >=80% draft to the prescribed sheet thickness. The resultant cold rolled sheet is annealed so that >=30μm crystalline grain size is obtained. By this procedure, a texture, where crystalline grains in which (200) plane is oriented in rolling surface comprise <=20% can be formed. It is preferable to regulate hot rolling temp. to 700-1200 deg.C. By this method, a pole shoe material for deflection yoke, minimal in collor slippage and beat tofie, stably working in a service temp. region, and excellent in workability, can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an Fe--Ni alloy plate, and more particularly, to a method for producing a deflection yoke of a cathode ray tube display, which is used as a pole piece for an excellent deflection. An object of the present invention is to provide a method for manufacturing a ferromagnetic material having a texture controlled to have characteristics.

[0002]

2. Description of the Related Art The deflection yoke component described above is required to have a small color shift at the center of the screen, a small color shift at the periphery of the screen, a low beat sound, and the like. In the past, pure iron or silicon steel plate was used as the pole piece material for the deflection yoke of the cathode ray tube, but each of these had disadvantages such as large deviation of the center of the plane and loud noise.
None of them satisfied the requirements. In order to overcome such a situation, one of the present applicants is disclosed in Japanese Patent Application Laid-Open No. 7-2543.
No. 77, the Fe-
It has been proposed to use Ni alloy as the deflection yoke component. The Fe—Al alloy is not suitable as a pole piece material for a deflection yoke because it has a loud beating sound and is inferior in workability similarly to a silicon steel plate.

[0003] The magnetostriction of an Fe-Ni alloy is as follows.
(200) and (111) magnetostriction constants (λ ₂₀₀ , λ ₁₁₁ )
Are known, the magnetostriction of the single crystal and lambda _200, indicated by the sum of lambda _111. The saturation magnetostriction constant of a polycrystalline Fe—Ni alloy is expressed as λ _S = 0.4 × λ ₂₀₀ + 0.6 × λ ₁₁₁ .

[0004] As for Fe-Ni alloy, Fe-Si alloy and pure iron, magnetostriction as shown in FIG. 1 (Table 1) is known. 42% Ni-Fe, 45% Ni-F shown in Table 1
e, the magnetostriction of the 50% Ni—Fe alloy is such that the polycrystalline saturation magnetostriction constant λ _S is a large value exceeding 10 × 10 ⁻⁶ , but the magnetostriction λ ₂₀₀ of the single crystal (200) plane is a small value. ,
When the (200) plane is gathered on the rolled surface by controlling the crystal orientation, the magnetostriction in the longitudinal direction of the pole piece can be suppressed low, and the beating noise during excitation and operation of the deflection yoke can be reduced.

On the other hand, λ ₁₁₁ of the 3.5Si—Fe alloy is small, but λ ₂₀₀ is large, so that polycrystal has large magnetostriction. 6.5Si-Fe has small magnetostriction but is difficult to process.

According to Japanese Patent Application Laid-Open No. Hei 7-126753 concerning a method for producing an Fe-Ni alloy, 30-85% Ni-
The final permeability of the hot-rolled sheet of the Fe alloy is subjected to final cold rolling at a total draft of 30% or more, followed by magnetic annealing in a temperature range of 900 to 1200 ° C. to control the average crystal grain size to 100 μm or more. There example mu _max = high as about 7 × 10 ^4, a method of obtaining a soft magnetic material suitable as a magnetic head or a magnetic shield has been proposed. The maximum cold rolling reduction shown in the examples in this publication is 75%. In the present invention, a high magnetic permeability is obtained by releasing the strain energy accumulated in the grain boundaries in the magnetic annealing process and causing secondary recrystallization, and increasing the average crystal grain size.

Further, the applicant's Japanese Patent Publication No. 23864/1986
According to the publication, forging, hot rolling, cold rolling, annealing, cold rolling, annealing, cold rolling (for a working ratio of 90
%) To obtain a shadow mask material having a thickness of 0.13 mm. By this step, the line unevenness due to the component segregation disappears, but the final annealing for controlling the texture is not performed.

[0008] By the way, about 83% Ni-Fe alloy is λ _s
It is well known that ≒ 0, but a Ni—Fe alloy having a composition in the vicinity of this value has a low saturation magnetic flux density B _{S and a} low inductance in a high magnetic field region. Not optimal. On the other hand, 30% Ni
Since -Fe and 36% Ni-Fe have a low Curie point, the saturation magnetic flux density B _S decreases in the operating temperature range (about 100 to 200 ° C.) of the deflection yoke, and the characteristics as a ferromagnetic material are lost. Not suitable for pole piece material for deflection yoke. Therefore, the Fe—Ni alloy composition suitable as a deflection yoke has a Ni content limited to more than 36% and less than 80%. Further from the viewpoint of magnetostriction lambda ₂₀₀ decreases Ni =
A composition range of 40 to 50% is preferred.

[0009]

SUMMARY OF THE INVENTION In view of the above-mentioned state of the art, the present invention relates to the above-mentioned preferred composition (about 40% Ni
It is an object of the present invention to provide a method for controlling the texture of a rolled Fe—Ni alloy sheet having a thickness of about 50% Ni) so as to obtain low magnetostriction characteristics required for a deflection yoke.

[0010]

According to the present invention, there is provided an Fe-Ni alloy according to the present invention.
The method of manufacturing the alloy plate is as follows: Ni: 38% to 52% (% by weight,
The same applies hereinafter), C: 0.10% or less, Si: 0.5% or less, Mn: 0.1 to 2.0%, and melts an Fe-Ni-based alloy consisting of the balance Fe and other unavoidable impurities. In a method of manufacturing an Fe—Ni alloy sheet by hot rolling an ingot that has been cast and cold rolling the obtained sheet material, cold rolling is performed at a working ratio of 80% or more to obtain a cold roll having a predetermined thickness. By annealing the cold-rolled sheet so that the crystal grain size becomes 30 μm or more, the crystal grains with the (200) plane oriented in the rolled surface are 35% or more and the crystal grains with the (111) plane oriented in 20%. The following texture is formed.

The reasons for limiting the composition of the Fe—Ni alloy of the present invention will be described below. Fe-Ni alloy satisfying various required characteristics of pole piece material for deflection yoke of cathode ray tube
When the content is in the range of 38% to 52%, the color misregistration is small, it operates stably in the operating temperature range, and is excellent in workability.
More specifically, when the Ni content is less than 38%, the Curie point becomes 200 ° C. or less, so that the saturation magnetic flux density B _s decreases in the operating temperature range (about 100 to 200 ° C.) of the deflection yoke, and the soft magnetic property decreases. Material properties are lost. If Ni exceeds 52%, the magnetostriction is large, and it is difficult to reduce the magnetostriction even when the crystal orientation is adjusted. Therefore, the Ni content is set to 38 to 52%.

C: When C exceeds 0.1%, the formation of iron carbide is remarkable, and the hardness of the alloy is remarkably increased, so that press formability is difficult. Therefore, C is set to 0.1% or less. . Si: Si is added for the purpose of deoxidation, but if it exceeds 0.5%, the hardness of the alloy is remarkably increased, so that press forming becomes difficult. Therefore, Si is set to 0.5% or less. Mn: Mn is added for the purpose of deoxidation and for imparting hot workability. If it is less than 0.1%, the deoxidizing effect is insufficient and the hot workability is poor. If the content of Mn exceeds 2.0%, the hardness of the alloy increases, and sufficient press-formability cannot be obtained. Therefore, the Mn content is set to 0.1 to 2.0%.

[0013] A Fe-Ni alloy having the above-described composition is melted and cast into an appropriate shape, and a sheet material is obtained by hot rolling. The temperature of the hot rolling is preferably from 700 to 1200C.

Subsequently, the hot-rolled sheet is directly cold-rolled at a working ratio of 80% or more, or is subjected to processing and annealing to reduce the thickness as appropriate to obtain a final cold-rolled work of 80% or more. Cold rolling is performed at a predetermined rate to obtain a predetermined plate thickness, and then annealing is performed so that the crystal grain size is 30 μm or more, preferably 50 μm or more. % Or more, and at least the (111) plane forms a texture of 20% or less in the rolled sheet. Here, if the working ratio of the cold rolling is less than 80% and / or the crystal grain size after annealing is 30 μm, the desired texture cannot be obtained.

In a plate having a thickness of 1 mm or less, the entire cross section has the above texture. When a rolled Fe-Ni alloy rolled plate having a large number of (200) crystal grains and a small number of (111) crystal grains is used as a deflection yoke and excited in a direction perpendicular to the rolled plate, the direction of the magnetic flux has the highest magnetostriction. Since the direction becomes smaller, the beating sound of the deflection yoke is reduced. Also, even if the magnet is excited in parallel with the rolling surface, no magnetostriction occurs in the (111) plane, so that the beating sound of the deflection yoke is also reduced.

The above-mentioned cold rolling is carried out so as to reach a working ratio of 80% or more in one pass or several passes. Annealing can be performed under conditions that recover workability but do not cause recrystallization in the middle of multiple passes of cold rolling. The annealing performed after the cold rolling is preferably performed at a temperature of 800 ° C. or higher.

In general, the required quality of the deflection yoke magnetic pole piece material includes the following five items. To reduce the color shift at the center of the screen, the residual magnetic flux density and coercive force of the pole pieces must be small. In order to reduce the color shift at the peripheral portion of the screen, the magnetization should not be saturated in the high magnetic field region, and the inductance should be high and should not be reduced in the high magnetic field region. In order to reduce the beating noise, the material does not expand or contract due to the fluctuation of the magnetic field, that is, the magnetostriction is small. The magnetic transformation temperature (Curie point) must be higher than the driving temperature range so that the pole piece material can stably exhibit the characteristics as a ferromagnetic material. Finally, it is required that processing is easy and formation into a part shape is easy.

[0018]

EXAMPLE An Fe-Ni alloy and an Fe-Si alloy having the compositions shown in FIG. 2 (Table 2) were melted, cast, forged, and hot-rolled sheet materials (2 to 6 mm thick) were obtained. Next, the sheet material obtained by this hot rolling was formed into a sheet material having a thickness of 0.3 mm by repeating cold working and annealing at a working ratio of 30 to 95% shown in Table 2 and then obtained from 700 to 300 shown in Table 2 also. Anneal at a temperature of 1100 ° C. Rolled materials (Nos. 1 to 3) having a working ratio of 80% or more in the table and an annealing temperature of 1000 ° C. or more are examples of the present invention, and others are comparative examples or reference examples.
After the final annealing, the results of measuring the X-ray diffraction intensity ratio and the crystal grain size and evaluating the above characteristics are shown in FIG. 2 (Table 2).

In the evaluation of the following characteristics, those satisfying the following criteria were passed (o), and those not satisfied were rejected (x).
And Small color shift at the center of the screen-coercive force: H _C ≤ 25A
/ M Small color shift around screen-Saturation magnetic flux density: B _S ≧
0.7T Low beating sound-Magnetostriction constant: λ ≤ ± 7 × 10 ^{-5 The} pole piece material stably exhibits the properties as a soft magnetic material-Curie point: T _C ≥ 200 ° C) Easy to form into shape.

The diffraction intensity ratio (R) of the (111) plane and the (200) plane was obtained by the following equation. R ₍₁₁₁₎ = I ₍₁₁₁₎ / I _total × 100 (%) R ₍₂₀₀₎ = I ₍₂₀₀₎ / I _total × 100 (%) where I is the diffraction intensity and I _total = I ₍₁₁₁₎ + I _{( 200)} +
I ₍₂₂₀₎ + I ₍₃₁₁₎ .

3.5% Si shown in Table 2 as a reference example
-Fe (Nos. 10, 12) has a high degree of orientation in the (200) plane, but is not optimal as a pole piece material for a deflection yoke because of large magnetostriction and a loud whine during use. Similarly, as a reference example, 6.5% Si—Fe (No. 1)
1, 13) is not optimal as a pole piece material for a deflection yoke because its material is brittle and it is difficult to process it into a pole piece. No. of the comparative example. Nos. 4, 5, and 6 have a Ni content of 38% to 52% suitable as a pole piece material for a deflection yoke, and have large crystal grains, but have a small degree of orientation of the (200) plane and a normal crystal orientation. To have large magnetostriction,
I want a loud noise during use. No. of the comparative example. 14-1
No. 6 has a Ni content of 42% suitable as a pole piece material for a deflection yoke, but (200)
The degree of plane orientation is reduced, resulting in large magnetostriction and a loud noise during use. Comparative Examples 7 and 8 are extremely high (20
0) Although it has a degree of plane orientation, it does not have stable characteristics as a ferromagnetic material due to a low Curie point due to a low Ni content. Comparative Example 9 has a high Ni content but a saturated magnetic flux density B _s
Is not suitable as a pole piece material for a deflection yoke because the inductance is reduced in a high magnetic field region due to the low magnetic field.

On the other hand, N corresponding to the embodiment of the present invention
o. 1-3 are excellent in all performance, color shift, beat sound is small, it operates stably in the operating temperature range,
A pole piece material for a deflection yoke of a cathode ray tube having excellent workability can be provided.

[Brief description of the drawings]

FIG. 1 is a chart (Table 1) showing magnetostriction of an Fe—Ni alloy and an Fe—Si alloy.

FIG. 2 is a table (Table 2) showing rolling reduction rates, annealing temperatures, and characteristics of Examples, Comparative Examples, and Reference Examples.

──────────────────────────────────────────────────の Continuation of front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C22F 1/00 623 8719-4K C22F 1/00 623 660 8719-4K 660C 661 8719-4K 661Z 685 8719 −4K 685 694 8719 −4K 694A

Claims (2)

[Claims] 1. Ni: 38% to 52% (weight%, the same applies hereinafter), C: 0.10% or less, Si: 0.5% or less, M
n: containing 0.1 to 2.0%, by hot rolling an ingot cast by melting and casting an Fe-Ni alloy containing the balance of Fe and other unavoidable impurities, and cold rolling the obtained sheet material. In the method for producing an Fe—Ni alloy sheet, cold rolling is performed at a working ratio of 80% or more, and a cold-rolled sheet having a predetermined thickness is annealed so that the crystal grain size becomes 30 μm or more. Producing a Fe-Ni alloy sheet, wherein a texture is formed in which the crystal grains with the (200) plane oriented are 35% or more and the crystal grains with the (111) plane oriented are 20% or less. Method. 2. The method for producing an Fe—Ni alloy sheet according to claim 1, wherein the annealing is performed so that the crystal grain size becomes 50 μm or more.