JP3536059B2 - Fe-Ni 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 has excellent resistance to deformation due to a drop impact in a state of being incorporated in a cathode ray tube even when pressed so that the shape of an electron beam transmitting portion of a shadow mask becomes completely flat, and doming. The present invention relates to an alloy ribbon for a flat mask that can maintain low thermal expansion without causing a crack, and in particular, by controlling the crystal orientation, the Young's modulus, which is an index of drop impact deformation resistance, was improved and low thermal expansion was maintained. The present invention relates to an Fe-Ni alloy ribbon for a flat mask.

[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 has its own challenges, but it is said that pressing the surface of the shadow mask closer to a flat surface by pressing is basically more difficult than that of a stretch method such as an aperture grill (for example, [NIKKEI EC
TRONICS] 1999.7.26 (No.748) p. 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 the spherical surface, the incident angles of the electron beam emitted from the electron gun at the four corners of the mask become acute angles. 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.

Although not intended for flat masks, in an attempt to improve thermal expansion characteristics and impact resistance, Japanese Patent No. 2723718 (Right holder: Yamaha Corporation) has reported that 2 to 7
% Fe-Ni-Co alloy containing Co (Super Inva
It has been proposed to reduce the coefficient of thermal expansion by using a shadow mask for r). However, Co is 2-7
%, It becomes expensive, and the tensile strength after softening annealing before pressing, especially Young's modulus, is not sufficient to withstand the drop impact when the mask is flat. It was Further, in Japanese Patent No. 1854642 (Right holder: Nikko Metal Co., Ltd.), Ni is 34 to 38% of Fe-
Ni-based alloys with Ti, Zr, B, Mo, Nb, N, P, C
0.01 to 1.0% in total of one or more of u
It has been proposed to prevent buckling due to impact at the time of assembly by including it, but the thermal expansion coefficient is 10 × 10.
^{The value} exceeds ⁻⁷ / ° C., which is not satisfactory in terms of suppressing color shift 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.
It is possible to suppress the thermal expansion coefficient by using an Fe-32% Ni-5% Co alloy as a base, but Co and the additional elements result in an expensive material.

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 at a low cost. Therefore, a Young's modulus after press-softening annealing is applied to improve drop impact deformation resistance with a very small amount of additive element. Increase
Fe-N used for flat type shadow mask
It is to develop an i-based alloy ribbon.

[0009]

Means for Solving the Problems The present inventor diligently investigated a method of increasing the Young's modulus by adding as little as possible by utilizing elements such as Nb, Ti, and Hf, which are known to have Young's modulus improving effects. Researched. 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-based 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 (200).
It has a strong correlation with the plane X-ray diffraction intensity composition ratio, and the Young's modulus sharply decreases when the (200) plane X-ray diffraction intensity ratio exceeds 75%, and below 75%, the (200) plane X-ray diffraction intensity ratio. It was found that the Young's modulus increased slightly with decreasing. It was found that the (200) plane X-ray diffraction intensity ratio inside the plate thickness obtained by removing 5% or more of the plate thickness from the surface after softening annealing is almost determined by that of the ribbon.

Then, in order to control the (200) plane X-ray diffraction intensity ratio of 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 having 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. . In this way, after the final annealing, cold rolling of 30 to 65% is performed to soften the cold-rolled ribbon, and 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, according to the present invention, (1) based on the mass percentage (%) (hereinafter referred to as%) Ni: 33 to 37 mass%, Nb and Ti, one kind or two kinds in total, 0.05 to. 0.5% content, Mn: 0.01-0.1% content,
The balance consists of Fe and unavoidable impurities, and the plate thickness is 0.05.
mm-0.3 mm, softening at 700 ° C or higher after cold rolling
A (200) plane X-ray diffraction intensity composition ratio α (200) of a blunted Fe-Ni alloy thin ribbon having a thickness of 5% or more removed from the surface is expressed by Equation 1. , Α (200)
Of 75% or less and having improved Young's modulus after softening and annealing, Fe for press mold flat mask
-Ni-based alloy ribbon.

[0013]

[Equation 3]

(2) Based on the mass percentage (%)
Below, expressed as%) Ni: 33 to 37 mass%, Nb and Ti are 1 type
Alternatively, the total content of the two types is 0.05 to 0.5 %, and Mn: 0.01 to 0.
Containing 1 % and the balance Fe and unavoidable impurities,
Fe with a plate thickness of 0.05 mm to 0.3 mm after cold rolling
- (200) plane X-ray diffraction intensity composition ratio β of a Ni-based alloy ribbon with 5% or more of the thickness of the ribbon removed from the surface
When (200) is expressed by Equation 2, β (200) is 25% to 7
5%, which means that the Young's modulus after softening and annealing was improved.
Press mold Fe-Ni alloy thin strip for a flat mask, wherein.

[0015]

[Equation 4]

[0016] (3) of the inevitable impurities, C: 0.0020 ~
0.0070% , Si: 0.001 to 0.030% , N: 0.0005 to 0.0050% , S: 0.
0015% or less (1) or (2)
Fe-Ni compound for press mold flat mask described in
Gold ribbon. (4) The temperature of the ribbon is 800 seconds or more for 5 seconds or more before the final cold rolling.
℃ or more and the crystal grain size according to JIS G 05
The austenite grain size number specified in No. 51 is recrystallization annealed into fine grains of 8.0 or more, and the final cold rolling is performed by 30
% To 65% to improve the Young's modulus after softening and annealing, and the Fe-Ni alloy ribbon for a press-molding flat mask according to (1) to (3) .

(5) The Fe—Ni-based alloy ribbon for a press-molding flat mask according to (1) to (4) , which is characterized by performing strain relief annealing after the final cold rolling.

[0018]

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 does not generate harmful martensite structure such as increase in press workability and thermal expansion and achieves low thermal expansion, so that it is in the range of 33 to 37%, preferably 34 to 36%. And 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 0.05%, it is not effective,
If it exceeds 0.5% , the etching property is lowered and the thermal expansion is increased. Not only it is necessary to set the range of 0.05% to 0.5% by itself, but the total content thereof is
It is necessary to set it in the range of 0.05% to 0.5% . 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
Average thermal expansion coefficient of 0 ℃ is 12 × 10 ^- in order to achieve a ⁷ / ° C. or less, and 0.01% to 0.1%, preferably
It is required to be 0.01 to 0.05% . Si: Si has a deoxidizing effect on the molten metal, but 0.030%
If it exceeds the limit , the etching performance will deteriorate significantly.
Is 0.030% or less. C: C enters as inevitable impurities from the melting raw material, the auxiliary raw material, and the melting furnace material. C is Nb
Alternatively, it works effectively to form a carbide with Ti and control it to a desired crystal orientation. The effect appears at 0.0020% or more. However, when C exceeds 0.0070%, carbides are excessively formed to deteriorate the etching piercing property. Therefore,
The amount is 0.0020% to 0.0070%, preferably 0.0020% to 0.0050%.

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 appears at 0.0005% or more. However,
When N exceeds 0.0050%, excessive nitrides are formed to deteriorate etching piercing property, and the annealing softening temperature is increased to deteriorate press formability. Therefore, 0.0005% ~ 0.005
It is set to 0%, preferably 0.0005% to 0.0030%.

S: S enters as unavoidable impurities from the melting raw materials, auxiliary raw materials, and melting furnace materials. Fe with low Mn content
In Ni-based alloys, hot cracking easily occurs when S is contained. To ensure hot workability, 0.00
15% or less, preferably less than 0.0010%.

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 700 ° C. or higher in a non-oxidizing atmosphere such as a reducing atmosphere.
(For example, in hydrogen at 900 ° C. for 30 minutes) to give press moldability. 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 subjected to blackening treatment in the atmosphere or 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, a nearly perfect plane form with an outer surface radius of curvature R: 100,000 mm or more and flatness: maximum height of screen curved surface portion / effective screen diagonal dimension = 0.1% or less. Is to have.

The press-molding type flat mask of the present invention comprises:
The average coefficient of thermal expansion over 30 to 100 ℃ is 12x10 ^-7 / ℃
While being kept below, the Young's modulus is 120,000 N / mm ² or more after annealing for imparting the above-mentioned press formability. If the Young's modulus is 120,000 N / mm ² or more, mask deformation does not occur even with a completely flat cathode ray tube in the cathode ray tube drop test described above. In order to improve the Young's modulus, the components specified in the present invention are satisfied and, after cold rolling, 700 ° C.
Or more (200) faces that were removed from the anneal thin plate and was the surface more than 5% thickness surface X-ray diffraction intensity component ratio alpha (2
00) is expressed by the equation 1, it is specified that α (200) is 75% or less.

[0026]

[Equation 5]

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. (2 with the effect of layers removed
The present inventors have found that there is a good correlation between the ₍ 00) plane X-ray diffraction intensity constituent ratio α ₍₂₀₀₎ and the Young's modulus of the material. For example, according to FIG. 1, if α ₍₂₀₀₎ is 75% or less, Young's modulus is 120,000 N / mm 2 or more,
Preferred ones are obtained.

The (200) plane X-ray diffraction intensity composition ratio β (2) of the surface from which 5% or more of the strip thickness before softening annealing is removed from the surface
00) is expressed by Equation 2, β (200) is 25% to 75%.
Stipulates that From FIG. 2 showing the relationship between α (200) and β (200), the range of α (200) of 75% or less is β (200) 25% to 75%, and this range is preferable. To be grasped.

[0029]

[Equation 6]

The removal of 5% or more from the surface of the material of the ribbon is carried out by the (200) plane X-ray diffraction intensity composition in the state where the influence of the surface processing layer of the material is removed as in the case of the softened and annealed material. 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-based alloy ribbon for press-molding type flat masks having improved Young's modulus after softening and annealing.

The press mold type flat mask of the present invention is
It is possible to achieve a Young's modulus of 135,000 N / mm2 or more, and further a Young's modulus of 140,000 N / mm2 or more.

[0033]

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

[0034]

[Table 1]

A vacuum induction melting furnace (VIM
It was melted in a furnace. 3m by forging and hot rolling after melting
After making m thickness, cold rolling and bright annealing are repeated, and about 0.12
A cold rolled material with a thickness of mm was used. Then, the shadow mask material with slits and the specified plate width is annealed in a reducing atmosphere.
(900 ° C. × 30 minutes in hydrogen) to give press moldability.

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 ₍₂₀₀₎ and β were calculated according to Equations 1 and 2.
₍₂₀₀₎ was calculated. The Young's modulus of the annealed material was measured at room temperature by the bending resonance method according to "JIS R 1605".

In 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 was measured, and the surface of the etched surface was observed by spraying 45 ° Baume ferric chloride aqueous solution at 60 ° C for 1 minute at a pressure of 0.3 MPa. . The results are shown in Table 2.

[0038]

[Table 2]

Samples Nos. 1 to 7 of the present invention have a target Young's modulus of 120,000 N / mm ² or more without exceeding the allowable level of thermal expansion coefficient (12 × 10 ⁻⁷ / ° C.). In particular, Sample Nos. 1 to 6 achieved Young's modulus of 140,000 N / mm ² or more. X of (200) surface of alloy No. 1 annealed material
Figure 1 shows the relationship between the line diffraction intensity composition ratio α ₍₂₀₀₎ and Young's modulus.
Shown in. The horizontal axis represents the X-ray diffraction intensity constituent ratio α ₍₂₀₀₎ of the (200) plane after the annealed material, and the vertical axis represents the Young's modulus. The annealing conditions were 800 ° C. × 30 minutes in a hydrogen gas atmosphere.
From FIG. 1, when α ₍₂₀₀₎ is 75% or less, the Young's modulus is 120,000 N / mm 2 or more, which is preferable.

In sample Nos. 4 to 7, since the impurity elements C, Si, S, and N exceeded the prescribed levels of claim 3 , respectively, the condition of the etching surface was not good, and minute irregularities and etching marks of foreign matter were observed. Was observed, but there was no problem in use.

On the other hand, in samples Nos. 8 to 9, the average thermal expansion coefficient was high because the Ni content was out of the specified range.
Sample No. 10 has a high average Mn content and thus a high average coefficient of thermal expansion. Sample No. 11 has a low Young's modulus and very poor strength characteristics because Nb and Ti are not added. Sample No.12
Has a high average thermal expansion coefficient because the Nb content is excessive,
Etching property is poor.

Sample Nos. 17 to 21 were (200) after annealing.
Since the X-ray diffraction intensity α (200) of the surface is strong, the Young's modulus is low.

As described above, an alloy in which an appropriate amount of Nb and Ti is added to provide insufficient drop impact deformation resistance while achieving low thermal expansion by controlling the Mn content contained in the Fe-Ni alloy containing an appropriate nickel concentration to a low level. On the basis of (20
By controlling the X-ray diffraction intensity α (200) of the (0) plane,
Fe-Ni alloys for press mold flat masks can now 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]

[FIG. 1] (2 after annealing of alloy No. 1 introduced in the example)
It is a figure which shows the relationship between the X-ray-diffraction intensity | strength composition ratio alpha _{(200) of a (} 00) surface, and a Young's modulus.

FIG. 2 is a diagram showing the relationship between the X-ray diffraction intensity composition ratios β _{( 200)} and α ₍₂₀₀₎ of the (200) plane of alloy No. 1 rolled material and annealed material.

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 a mass percentage (%) (hereinafter referred to as%), Ni: 33 to 37 mass% and one or two kinds of Ti are contained in a total amount of 0.05 to 0.5%, and Mn: 0.01-0.1%, balance Fe and unavoidable impurities, and plate thickness of 0.
05mm-0.3mm, soft at 700 ℃ or higher after cold rolling
A chemical-annealed Fe-Ni alloy ribbon, which comprises:
When the (200) plane X-ray diffraction intensity composition ratio α (200) of the surface in which 5% or more of the plate thickness is removed from the surface is expressed by Equation 1, α (20
0) is 75% or less, and the Young's modulus after softening annealing is improved, and the Fe-Ni alloy ribbon for a press-molding type flat mask is characterized. [Equation 1] 2. Based on the mass percentage (%) (hereinafter referred to as%
Notation) Ni: 33 to 37 mass%, Nb and Ti 1 type or 2 types
Content of 0.05 to 0.5 %, and Mn: 0.01 to 0.1 %.
Which has a balance of Fe and unavoidable impurities, and has a plate thickness
Fe-Ni after cold rolling with 0.05 mm to 0.3 mm
A system alloy ribbon, (200) plane X-ray of the surface removal of more than 5% of the plate thickness ribbon from the surface diffraction intensity component ratio beta (20
0) is expressed by Equation 2, β (200) is 25% to 75%, and the Young's modulus after softening annealing is improved. . [Equation 2] 3. Of the inevitable impurities, C: 0.0020 to 0.0070.
% , Si: 0.001 to 0.030% , N: 0.0005 to 0.0050% , S: 0.0015%
The following is provided in claim 1 or claim 2.
Fe-Ni based alloy for press mold flat mask described
Thin strip. 4. Before the final cold rolling, the temperature of the ribbon is set to be not less than 5 seconds and not less than 800 ° C., and the grain size is JIS G.
8. Austenite grain size number specified in 0551.
0 or more it becomes fine as recrystallization annealing, 1 to claim, characterized in that the final cold rolling with improved Young's modulus after anneal by performing 30% to 65% of working ratio
Fe- for a press-molding type flat mask according to claim 3.
Ni-based alloy ribbon. 5. The Fe-Ni alloy ribbon for a press-molding flat mask according to claim 1 , wherein strain relief annealing is performed after the final cold rolling.