JP3515769B2 - Fe-Ni-Co alloy ribbon for press-molded flat mask - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shadow mask which is pressed so that the electron beam transmitting portion has a completely flat shape and is excellent in deformation resistance due to a drop impact in a state where it is incorporated in a cathode ray tube, and doming occurs. It is related to alloy ribbon for flat mask that can maintain low thermal expansion,
In particular, the present invention relates to the Fe-Ni-Co alloy ribbon for a flat mask, in which the Young's modulus, which is an index of drop impact deformation resistance, is improved by controlling the crystal orientation, and the low thermal expansion is maintained.

[0002]

2. Description of the Related Art In a color cathode ray tube, an electron beam emitted from an electron gun is applied to a phosphor inside a glass panel to display a screen. The deflection yoke controls the direction of the electron beam by magnetic force. In front of the glass panel, there is provided a mechanism that divides the electron beam into pixel units so that the electron beam strikes a predetermined phosphor, which is called a mask or a color selection mechanism. The mask for the color cathode ray tube has a shadow mask method in which the mask material is etched into dots or slots and then press-molded,
It is roughly divided into an aperture grill method in which a frame material is stretched and stretched by applying a strong pulling force to the frame material after etching in a blind shape. Each method has advantages and disadvantages, and both methods are used in the market.

By the way, many attempts have been made to develop a flat screen for flattening the display screen. Here, the flat screen is a flat screen of a conventional spherical display screen that is almost completely perfect. One of the big problems when trying to flatten the screen of a cathode ray tube is how to make the shadow mask and the aperture grill flat. Each of them has its own problems, but it is said that it is basically more difficult to make the surface of the shadow mask closer to a flat surface by a press than that of an extension method such as an aperture grill (for example, [NKKE
I ELECTRONICS] 1999.7.26 (N
o. 748) 128).

This is because the shadow mask is manufactured by press-molding a metal sheet. Therefore, unlike the stretching method, it is necessary to maintain the shape by a self-maintaining shape. Basically, the shape is maintained unless it is spherical. This is because it cannot be done. On the other hand, the flat mask is difficult to maintain the shape because it makes the mask almost flat. The only way to solve this is to increase the strength of the mask. The "mask strength" referred to here is different from the meaning of the strength of general metal (for example, the strength by a tensile test), and is whether or not the mask is deformed by giving an impact to the entire cathode ray tube after the cathode ray tube is assembled. Specifically, the cathode ray tube is dropped from a certain height to test whether the mask is deformed. The development of a mask that is resistant to such impact deformation, that is, improved in the resistance to drop impact deformation, is required for the flat tube.

Further, the flat tube is required to have excellent doming characteristics. That is, as the mask becomes flatter from a spherical surface, the incident angle of the electron beam emitted from the electron gun at the four corners of the mask becomes acute. That is, this means that the mask is only slightly displaced due to thermal expansion, the electron beam is mislanded, and a problem of color misalignment occurs. This necessitates the development of low-expansion masks whose thermal expansion is significantly lower than conventional masks. In order to increase the degree of freedom in designing the flat mask and prevent the problem of color misregistration as much as possible, the average thermal expansion coefficient at 30 to 100 ° C. is 7 × 10 ⁻⁷ / ° C. or less, preferably 2 to 5
For some flat masks, it is necessary to achieve × 10 ⁻⁷ / ° C. The present inventors have found that a Fe—Ni alloy having low thermal expansion characteristics and improved drop impact deformation resistance (Japanese Patent Application No. 2000-2000).
-192249) was developed, but the average coefficient of thermal expansion at 30 to 100 ° C was 8 to 11 × 10 ^-7 / ° C, and 7 × 10 ^-7.
/ C has not been achieved.

Although not intended for a flat mask, as an attempt to improve thermal expansion characteristics and impact resistance, Japanese Patent No. 2723718 (Right holder: Yamaha Corporation)
Fe-Ni-Co alloy containing 2 to 7% of Co (Sup
er Invar) is used as a shadow mask to reduce the coefficient of thermal expansion. However, when Co is contained in an amount of 2 to 7%, the price becomes high, and in addition, the tensile strength after softening annealing before pressing, especially Young's modulus, can withstand a drop impact when the mask is flattened. Was not completely satisfied. In addition, in Japanese Patent No. 1854642 (right holder: Nikko Metal Co., Ltd.),
Ni, 34-38% Fe-Ni alloy, Ti, Zr,
Proposed to prevent buckling due to impact during assembly by including 0.01 to 1.0% in total of one or more of B, Mo, Nb, N, P and Cu. However, the coefficient of thermal expansion exceeds 10 × 10 ⁻⁷ / ° C., and it is not sufficiently satisfactory in terms of suppressing color misregistration when the mask is flat.

[0007]

In general, the Fe-Ni alloy used for a shadow mask contains 36% Ni. This is because this composition has the smallest thermal expansion coefficient in the range of room temperature to 100 ° C. in which the shadow mask is used. If an element for improving the strength such as Nb is added to this alloy, the coefficient of thermal expansion increases, so it is not preferable to add a large amount. Further, the addition causes an increase in raw material cost.
Fe-32% is required for manufacturing a press-molding flat mask having an average coefficient of thermal expansion of 30 to 100 ° C. of 7 × 10 ⁻⁷ / ° C. or less and improved drop impact deformation resistance.
It was decided to repeat the study based on the Ni-5% Co alloy.

An object of the present invention is to supply a press-molding type shadow mask which can be used for a flat cathode ray tube, so that the Young's modulus after press softening annealing is increased in order to improve the drop impact deformation resistance with a very small amount of additional elements. Fe-Ni-Co used for a flat type shadow mask
It is to develop a series alloy ribbon.

[0009]

Means for Solving the Problems The inventors of the present invention have intensively studied and researched a method of increasing Young's modulus by adding as little as possible by using elements such as Nb and Ti, which are known to have Young's modulus improving effect. . As a result, it was found that the Young's modulus of the shadow mask after softening annealing before press forming was significantly changed by the crystal orientation inside the plate thickness after softening annealing of the rolled ribbon.

Specifically, Fe-N containing the above elements is added.
The i-Co alloy was processed into several types of cold-rolled ribbons with different workability, and Young's modulus after 800 ° C. annealing was examined.
As a result, they have found that the Young's modulus increases when Nb or Ti is contained and cold rolling is performed at a workability within a specific range. As a result of detailed examination, Young's modulus was measured on the surface of the strip after softening annealing, which was removed from the surface by 5% or more of the plate thickness (2
It has a strong correlation with the (00) plane X-ray diffraction intensity composition ratio,
It was found that the Young's modulus sharply decreased when the (00) plane X-ray diffraction intensity ratio exceeded 75%, and the Young's modulus slightly increased with the (200) plane X-ray diffraction intensity ratio decreased below 80%. . In addition, from the surface after softening annealing,
It was found that the (200) plane X-ray diffraction intensity ratio inside the plate thickness where more than 100% was removed is almost determined by that of the ribbon.

In order to control the X-ray diffraction intensity ratio of the (200) plane in the central portion of the plate thickness after annealing and softening the ribbon, the material is annealed before the final cold rolling at a temperature of 800 ° C. or higher. It turns out that it is important to hold for more than a second. It is considered that this is because carbides, nitrides, and borides with a concentration product with Nb or Ti are dissociated to some extent by annealing and redissolved, and finely reprecipitated in the cooling process after annealing. After the final annealing in this manner, cold rolling of 30 to 65% is performed to soften and anneal the cold-rolled ribbon, so that the (200) plane X-ray diffraction intensity ratio at the center portion of the plate thickness is desired. It was possible to set the range, and the present invention was completed.

Thus, the present invention provides: (1) Ni: 30-35 based on mass percentage (%).
%, Co: 2 to 8% and Mn: 0.01 to 0.5%, and Nb and Ti of 0.0 in total of one or two.
1 to 0.8%, balance Fe and unavoidable impurities. Of the unavoidable impurities, C: 0.0020 to 0.
0070%, Si: 0.001 to 0.030%, N:
0.0005 to 0.0050%, S: 0.0015% or less, the plate thickness is 0.05 mm to 0.3 mm, cold rolling
Fe-Ni-Co system after softening and annealing at 700 ° C or higher
It is a gold ribbon, and this ribbon is removed from the surface with a plate thickness of 5% or more.
Removed by the surface of the (200) plane X-ray diffraction intensity component ratio α
_{When (200)} is expressed by the equation (1) , α ₍₂₀₀₎ is 80%.
Fe-Ni- for a press-molding flat mask, which is characterized in that the Young's modulus after softening and annealing is improved.
Co-based alloy ribbon.

[0013]

[Equation 4] I _(hkl) : _(hk of the surface where 5% or more of the plate thickness is removed from the surface after soft annealing the ribbon at a temperature of 700 ° C. or more
l) Surface X-ray diffraction intensity

(2) Ni based on mass percentage (%):
30-35%, Co: 2-8% and Mn: 0.01-
It contains 0.5%, 0.01 to 0.5% of Nb and Ti in total of one kind or two kinds, and balance Fe and unavoidable impurities. Of the unavoidable impurities, C: 0. .0
020-0.0070%, Si: 0.001-0.03
0%, N: 0.0005 to 0.0050%, S: 0.0
The plate thickness of 015% or less is 0.05 mm to 0.3 mm
Fe-N soft-annealed at 700 ° C or higher after cold rolling
An i-Co alloy thin ribbon, which has a thickness of 5% or more.
When the (200) plane X-ray diffraction intensity composition ratio α ₍₂₀₀₎ of the surface from which is removed from the surface is expressed by the formula (1) , α ₍₂₀₀₎ is 80% or less and is defined by the formula (2). Fe for press molding type flat mask, characterized in that Ni segregation is 1.0% or less and Young's modulus after softening annealing is improved.
-Ni-Co alloy ribbon.

[0015]

[Equation 5] I _(hkl) : _(hk of the surface where 5% or more of the plate thickness is removed from the surface after soft annealing the ribbon at a temperature of 700 ° C. or more
l) Surface X-ray diffraction intensity ΔNi = C _x −C ₀ ...... ΔNi: Ni segregation rate C _x : Ni content rate (%) in streak portion C ₀ : Ni content rate (%) in streak vicinity portion

[0016] (3) Expressing cold rolling thin strip of thickness more than 5% was removed from the surface plane of the (200) plane X-ray diffraction intensity component ratio beta ₍₂₀₀₎ in equation (3), beta _{( 200)} is 25
% To 75%, and the Fe-Ni-Co alloy ribbon for a press mold type flat mask according to the above (1) or (2), which has improved Young's modulus after softening annealing.

[0017]

[Equation 6] I ′ _(hkl) : X-ray diffraction intensity of the (hkl) plane of the surface obtained by removing 5% or more of the thickness of the cold-rolled ribbon from the surface

(4) Before the final cold rolling, the temperature of the ribbon should be 5 seconds or more and 800 ° C. or more, and the grain size should be JI.
Young after softening annealing is performed by performing recrystallization annealing to fine grains of 8.0 or more with austenite grain size number specified in S G 0551 and performing final cold rolling at a workability of 30% to 65%. The Fe-Ni-Co based alloy ribbon for a press-molding flat mask according to the above (1) to (3), which has an improved rate.

(5) The Fe-Ni-Co alloy ribbon for a press-molding flat mask according to the above (1) to (4), wherein strain relief annealing is performed after the final cold rolling.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The basis of the present invention is to control the Young's modulus after softening annealing performed before pressing by controlling the (200) plane X-ray diffraction intensity constituent ratio within the plate thickness, thereby adding a strength increasing element. Is suppressed as much as possible, and the regulation of the C and N contents works effectively. As a manufacturing method, the workability of the final rolling, the material temperature in the annealing before the rolling, and the crystal grain size after the annealing are important.

The reasons for limiting the constituent elements, crystal orientations and manufacturing conditions relating to the present invention will be described below. Ni: Ni is
In order to achieve a low thermal expansion due to a synergistic effect with Co, a harmful martensite structure such as increase in press workability and thermal expansion is not generated, and in order to achieve low thermal expansion, preferably 3%.
The range is 1 to 33%. Co: Co not only reduces the thermal expansion but also plays a role in improving the yield strength. For this purpose, it is necessary to add 2% or more in balance with the Ni content, but on the other hand, if the addition amount exceeds 8%, the thermal expansion is increased in balance with the Ni content. Further increasing the content is also disadvantageous in terms of manufacturing cost and is not a good idea. In consideration of the Ni content, for the purpose of the present invention, 2 to 8%, preferably 4 to
Add in the range of 6%. Mn: Mn is added as a deoxidizing agent to the molten metal, but the addition thereof increases the coefficient of thermal expansion, so that it is 30 to 10
In order to achieve an average coefficient of thermal expansion at 0 ° C. of 7 × 10 ⁻⁷ / ° C. or less, the content is 0.01 to 0.5%, preferably 0.1 .
It is required to be 01 to 0.3%. Nb, Ti: Add as an element that can obtain a desired high yield strength without increasing the thermal expansion and further improve the Young's modulus. If it is less than 0.01%, the effect is not obtained, while if it exceeds 0.8%, the etching property is lowered and the thermal expansion is increased. Not only it is necessary to be in the range of 0.01% to 0.8% alone, but it is also necessary for the total content thereof to be in the range of 0.01% to 0.8%.
In manufacturing the alloy of the present invention, it is necessary to pay attention to the occurrence of Ni segregation from the viewpoint of the etching property of the mask. However, according to the findings of the present invention, when Nb and Ti are added, Fe-Ni is added. It is presumed that the solidus temperature and liquidus temperature in the Co-based alloy change, and Ni segregation easily occurs during casting and solidification. The present inventor has also found that the Young's modulus decreases when Ni segregation occurs. The reason for this decrease is that Ni segregation occurs,
It is estimated that the crystal orientation of the Fe-Ni-Co alloy changes and the Young's modulus changes. Ni segregation is affected not only by the Nb and Ti contents but also by the casting and forging conditions, but the Nb and Ti contents are each 0.01 to 0.5%.
Then, if their sum is 0.01 to 0.5%, Ni
The segregation ratio was 1.0% or less, and it was found that the streak unevenness due to the Ni segregation does not occur, as in the Fe-Ni-Co based alloy in which Nb and Ti are not added. Therefore, the Nb and Ti contents are each 0.01 to 0.5%, and their total is 0.01 to 0.5%. Si: Si has a deoxidizing effect on the molten metal, but 0.030%
If it exceeds 0, the etching property is greatly deteriorated.
001 to 0.030%. C: C enters as inevitable impurities from the melting raw material, the auxiliary raw material, and the melting furnace material. C effectively forms a carbide with Nb or Ti to control the crystal orientation to a desired one. The effect is exhibited at 0.0020% or more. However, C
When it exceeds 0.0070%, carbides are excessively formed to deteriorate the etching piercing property. Therefore, 0.0020-
0.0070%, preferably 0.0020 to 0.005
0%

N: N mainly enters as an unavoidable impurity due to contamination from the melting atmosphere. N acts effectively to form a nitride with Nb or Ti to control the crystal orientation to a desired one.
The effect is exhibited at 0.0005% or more. However, when N exceeds 0.0050%, nitrides are excessively formed to deteriorate the etching piercing property, and the annealing softening temperature becomes high to deteriorate the press formability. Therefore,
0.0005% to 0.0050%, preferably 0.00
05 to 0.0030%.

S: S enters as unavoidable impurities from the melting raw materials, auxiliary raw materials, and melting furnace materials. In the Fe—Ni—Co alloy having a low Mn content, hot cracking easily occurs when S is contained. In order to secure hot workability, 0.0015% or less, preferably 0.0010%
Less than%. α ₍₂₀₀₎ : In order to improve the strength of the flat mask, that is, the resistance to drop impact deformation, it is effective to raise the Young's modulus of the material (Patent No. 1854642 (Right holder: Nikko Metal Co., Ltd.)). Said. The inventors of the present invention have investigated the relationship between the (200) plane X-ray diffraction intensity constituent ratio α ₍₂₀₀₎ and the Young's modulus of the material in the state where the influence of the surface processing layer of the material softened and annealed for the purpose of ensuring press formability is removed. We found a good correlation between them. In order to obtain sufficient resistance to drop impact deformation, the Young's modulus of the material must be 120,000 N / mm ² or more, and α ₍₂₀₀₎ is 80% for that purpose.
You will need the following: β ₍₂₀₀₎ : The (200) plane X-ray diffraction intensity constituent ratio β ₍₂₀₀₎ in a state where the influence of the surface-treated layer in the cold-rolled foil strip is removed needs to be 25 to 75%. When the material to be filled is softened and annealed and the above-mentioned α ₍₂₀₀₎ is measured, it becomes 80% or less.

For the shadow mask material, for example, an alloy material having a required composition is melted in a vacuum induction melting furnace (VIM furnace), cast into an ingot, forged, hot rolled and cold rolled, and then bright annealed. Repeated cold rolling, and finally 0.05-
The final cold rolling is performed by rolling rolls that have been dull processed to a predetermined thickness in the 0.30 mm range. The thickness of various shadow mask materials manufactured by etching is 0.0
The thickness is generally 5 to 0.30 mm, and in particular, a flat mask of a press mold uses a material having a plate thickness of 0.1 to 0.13 mm. After that, slitting is performed to obtain a shadow mask material having a predetermined plate width. Shadow mask material
After degreasing, a photoresist is applied on both sides, a pattern is baked, and after development, etching and perforation processing is performed, and the shadow mask material unit is individually cut.

The shadow mask material unit is annealed at a temperature of 700 ° C. or higher in a non-oxidizing atmosphere, for example, a reducing atmosphere (for example, in hydrogen at 900 ° C. for 30 minutes) to give press formability. In the pre-annealing method, the above-described annealing is performed on the final cold rolled material before etching. After undergoing leveler processing, it is formed into a flat mask form by pressing.

Finally, the press-molded flat mask is degreased and then blackened in the air or in a CO / CO ₂ gas atmosphere to form a black oxide film on the surface.
The press mold “flat mask” of the present invention is, for example,
Outer surface radius of curvature R: 100,000 mm or more and flatness:
It has a nearly perfect plane form of maximum height of screen curved surface / diagonal size of effective screen = 0.1% or less.

The press-molding type flat mask of the present invention is
The average coefficient of thermal expansion over 30 to 100 ° C. is 7 × 10
^The Young's modulus is 120,000 N / mm after annealing for imparting the above-mentioned press formability while maintaining at ^-7 / ° C or less.
It is characterized by being ² or more. Young's modulus is 120,0
When it is 00 N / mm ² or more, mask deformation does not occur even in a perfect flat cathode ray tube in the above-described cathode ray tube drop test. In order to improve the Young's modulus, a cold-rolled ribbon satisfying the components specified in the present invention is softened and annealed at a temperature of 700 ° C. or higher, and then 5% or more of the plate thickness is removed from the surface (2
When the (00) plane X-ray diffraction intensity constituent ratio α ₍₂₀₀₎ is expressed by an equation, it is specified that α ₍₂₀₀₎ is 80% or less.

[0028]

[Equation 7] I _(hkl) : _(hk of the surface where 5% or more of the plate thickness is removed from the surface after soft annealing the ribbon at a temperature of 700 ° C. or more
l) Surface X-ray diffraction intensity

Here, the softening annealing is carried out by a mask processing manufacturer in order to ensure press formability of the material, while the removal of 5% or more from the surface of the material means the surface processing of the material. The present inventor has found that there is a good correlation between the (200) plane X-ray diffraction intensity constituent ratio α ₍₂₀₀₎ and the Young's modulus of the material in a state where the influence of the layer is removed. For example, according to FIG. 1, α ₍₂₀₀₎ is 8
If it is 0% or less, Young's modulus is 120,000 N / m.
m ² or more, and a preferable one is obtained.

The (200) plane X-ray diffraction intensity composition ratio β ₍₂₀₀₎ of the surface obtained by removing 5% or more of the thickness of the thin strip from the surface is represented by the equation (3) , β ₍₂₀₀₎ is 25% to It is specified to be 75%. From FIG. 2 showing the relationship between α ₍₂₀₀₎ and β ₍₂₀₀₎ , α ₍₂₀₀₎ is in the range of 80% or less because β ₍₂₀₀₎ is 25% to 75%, and this range is preferable. Is grasped.

[0031]

[Equation 8] I ' _(hkl) : X-ray diffraction intensity of the (hkl) plane of the surface in which 5% or more of the thickness of the thin strip is removed from the surface

As in the case of the softened and annealed material, the removal of 5% or more from the surface of the material of the ribbon is the (200) plane X-ray diffraction intensity composition in the state where the influence of the surface processing layer of the material is removed. The present inventors have found that there is a good correlation between the ratio β ₍₂₀₀₎ and the Young's modulus of the material.

As described above, the range of specific manufacturing conditions for manufacturing the shadow mask material having an improved Young's modulus will be described. Before the final cold rolling, the ribbon temperature is 5
The crystal grain size should be J
Recrystallization annealing is carried out so that the austenite grain size number specified in IS G 0551 is 8.0 or more.
The final cold rolling is performed with a workability of 30% to 65%. More preferably, strain relief annealing is performed after the final cold rolling. This makes it possible to manufacture a Fe-Ni-Co alloy ribbon for press-molding type flat masks having improved Young's modulus after softening and annealing.

The press-molding type flat mask of the present invention comprises:
Young's modulus: 140,000 N / mm ^TwoTo achieve the above
And Young's modulus: 150,000 N / mm
^TwoThe above can be realized.

[0035]

EXAMPLES Table 1 shows the compositions of alloys used as examples and comparative examples.

[0036]

[Table 1]

The alloys of these compositions are applied to a vacuum induction melting furnace (VI
It melted in the M furnace). After smelting, 3 by forging and hot rolling
After the thickness was reduced to mm, cold rolling and bright annealing were repeated to obtain a cold rolled material having a thickness of about 0.12 mm. Then, the shadow mask material having slits and having a predetermined plate width was annealed (900 ° C. × 30 minutes in hydrogen) in a reducing atmosphere to impart press formability.

Samples were taken from the annealed and rolled materials,
After removing 5 to 6% of the plate thickness on the front and back surfaces by etching, the main diffraction grating surfaces of the alloy are (111) and (20).
0), (220) and (311) planes were measured for X-ray diffraction intensity, and α was calculated according to equations (1) and (3) .
₍₂₀₀₎ and β ₍₂₀₀₎ were determined. The Young's modulus of the annealed material was measured at room temperature by the bending resonance method according to "JIS R 1605".

According to this method, a driving force from an oscillator is applied to the upper and lower surfaces of a test piece suspended by a drag thread on the driver side and the detector side so that free bending vibration can be achieved, and the maximum amplitude is passed through the detector. Is generated and the node of vibration is measured to determine the primary resonance frequency, and the dynamic elastic modulus is calculated from the primary resonance frequency and the mass and size of the test piece based on a predetermined formula. Further, the average coefficient of thermal expansion between 30 and 100 ° C is measured, and the surface of the etched surface is observed by spraying 45 ° Baume ferric chloride aqueous solution at 60 ° C for 1 minute at a pressure of 0.3 MPa. did. The results are shown in Table 2.

[0040]

[Table 2]

Sample No. of the present invention. 1 to 9 are thermal expansion coefficients
Is regarded as an acceptable level (7 × 10^{− 7}/ ° C)
The target Young's modulus is 120,000 N / mm
^TwoThe above was fully realized, and especially sample No. 1 to 6 is Yang
Gug rate: 140,000 N / mm ^TwoRealized the above.

Alloy No. The relationship between the (200) plane X-ray diffraction intensity constituent ratio α ₍₂₀₀₎ and the Young's modulus of the annealed material of No. 1 is shown in FIG.
Shown in. The horizontal axis represents the (200) plane X-ray diffraction intensity constituent ratio α ₍₂₀₀₎ after the annealed material, and the vertical axis represents the Young's modulus. The annealing conditions were 800 ° C. for 30 minutes in a hydrogen gas atmosphere. From FIG. 1, when α ₍₂₀₀₎ is 80% or less, the Young's modulus is 120,000 N / mm ² or more, which is preferable.

Sample No. 14 to 18 are M of impurity elements
Since each of n, C, Si, S, and N exceeded the prescribed level of claim 1, the state of the etched surface was not good, and minute irregularities and etching marks of foreign matter were observed.

On the other hand, the sample No. No. 10 has a high average thermal expansion coefficient because the Ni and Co contents are out of the specified range. Sample No. Since No. 11 has a low Ni content, it has a high average thermal expansion coefficient. Sample No. Since No. 12 has a high Co content, the average coefficient of thermal expansion is high. Sample No. 13 is
Since Nb and Ti are not added, the Young's modulus is low and the strength characteristics are very poor. Sample No. No. 14 has a high Mn content and thus has a high average thermal expansion coefficient. Sample No. In No. 15, the total amount of Nb and Ti added exceeds 0.8%, the average coefficient of thermal expansion is high, and the result on the etched surface is poor. Since Nb and Ti are not added, the Young's modulus is low and the strength characteristics are very poor. Sample No. Nos. 16 to 19 showed a result that the state of the etching surface was bad because the contents of C, Si, S and N were excessive.

Sample No. 20 to 23 are (20 after annealing).
Since the 0) plane X-ray diffraction intensity α ₍₂₀₀₎ exceeded 80%, the Young's modulus was low and the state of the etched surface was poor.

[0046]

As described above, while achieving a low thermal expansion by controlling the Mn content contained in the Fe-Ni-Co alloy containing appropriate nickel and cobalt concentrations to be low, the insufficient drop impact deformation resistance of Nb, Based on an alloy to which an appropriate amount of Ti is added, the (200) plane X-ray diffraction intensity α of this material after annealing
By controlling ₍₂₀₀₎ , the Fe-Ni-Co alloy for press-molding type flat mask can be manufactured. In this way, it is possible to cope with future flat type color cathode-ray tubes, and to perform stable and efficient production of a good press-molding type flat mask that is free from color shift and does not deform during handling.

[Brief description of drawings]

1 is an alloy No. introduced in the examples. It is a figure which shows the relationship between the Young's modulus and the (200) plane X-ray-diffraction intensity | strength composition ratio alpha ₍₂₀₀₎ after the annealing material of No. 1.

FIG. 2 Alloy No. It is a diagram showing a relationship between the first rolling member and the annealed material (200) plane X-ray diffraction intensity component ratio beta _{(20 0)} and alpha _(200).

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI H01J 29/07 H01J 29/07 Z

Claims (5)

(57) [Claims] 1. Based on mass percentage (%) (hereinafter referred to as%) Ni: 30 to 35%, Co: 2 to 8%, and Mn: 0.01 to 0.5% are contained, Furthermore, Nb: 0.
01-0.8% and Ti: 0.01-0.8%, one or two kinds selected from 0.01 to 0.8% in total, and the balance Fe and inevitable impurities. : 0.0020 to 0.0070%, S
i: 0.001-0.030%, N: 0.0005-
0.0050%, S: 0.0015% or less plate thickness
0.05mm-0.3mm, 700 ℃ or more after cold rolling
Fe-Ni-Co alloy ribbon that has been softened and annealed by
Then, the (200) plane X-ray diffraction intensity composition ratio α ₍₂₀₀₎ of the surface obtained by removing 5% or more of this thin strip from the surface is calculated by
Expressed by (1) , α ₍₂₀₀₎ is 80% or less, and the Young's modulus after softening annealing is improved, and the Fe-Ni-Co alloy ribbon for a press mold type flat mask is characterized. [Equation 1] I _(hkl) : _(hk of the surface where 5% or more of the plate thickness is removed from the surface after soft annealing the ribbon at a temperature of 700 ° C. or more
l) Surface X-ray diffraction intensity 2. Based on mass percentage (%) (hereinafter,%
Notated) Ni: 30 to 35%, Co: 2 to 8%,
And Mn: 0.01 to 0.5%, and Nb:
0.01-0.5% and Ti: 0.01-0.5%, 1 or 2 kinds selected in total 0.01-0.5
%, And the balance Fe and unavoidable impurities. Of the unavoidable impurities, C: 0.0020 to 0.0070.
%, Si: 0.001 to 0.030%, N: 0.000
5 to 0.0050%, S: 0.0015% or less of the plate
Thickness is 0.05mm-0.3mm, 700 ℃ after cold rolling
The Fe-Ni-Co alloy ribbon that has been soft-annealed as described above is
Then, the (200) plane X-ray diffraction intensity composition ratio α ₍₂₀₀₎ of the surface obtained by removing 5% or more of the thin ribbon from the surface is calculated by
Expressed by (1) , α ₍₂₀₀₎ is 80% or less, and Ni segregation defined by the formula (2) is 1.0% or less, and the Young's modulus after softening annealing is improved. Fe-Ni-Co alloy ribbon for press mold flat masks. [Equation 2] I _(hkl) : _(hk of the surface where 5% or more of the plate thickness is removed from the surface after soft annealing the ribbon at a temperature of 700 ° C. or more
l) Surface X-ray diffraction intensity ΔNi = C _x −C ₀ (2) ΔNi: Ni segregation rate C _x : Ni content rate (%) in streak portion C ₀ : Ni content rate (%) in streak vicinity portion 3. The (200) plane X-ray diffraction intensity composition ratio β of the surface obtained by removing 5% or more of the plate thickness of the cold rolled ribbon from the surface.
_{When (200)} is expressed by the equation (3) , β ₍₂₀₀₎ is 25%.
The Fe-Ni-Co based alloy ribbon for a press-molding type flat mask according to claim 1 or 2, wherein the Young's modulus after softening annealing is improved to be 75%. [Equation 3] I ′ _(hkl) : X-ray diffraction intensity of the (hkl) plane of the surface obtained by removing 5% or more of the thickness of the cold-rolled ribbon from the surface 4. Before the final cold rolling, the temperature of the ribbon is kept at 5 seconds or more and 800 ° C. or more, and the crystal grain size is JIS.
The Young's modulus after softening annealing is performed by recrystallizing annealing to a fine grain of 8.0 or more with austenite grain size number specified in G 0551, and performing final cold rolling at a workability of 30% to 65%. It is improved, Claim 1 characterized by the above-mentioned.
To F for a press-molding flat mask according to claim 3.
e-Ni-Co alloy ribbon. 5. The Fe—Ni—Co alloy ribbon for a press-molding flat mask according to claim 1, wherein strain relief annealing is performed after the final cold rolling.