JP2681855B2 - Aperture grill material and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material for an aperture grill used in a cathode ray tube for a color television and a method for manufacturing the same, and in particular, etching processability and line disturbance due to the etching process are small, and in addition, the tension is lowered during blackening. An object of the present invention is to provide a product having a characteristic that the color shift due to is small.

[0002]

2. Description of the Related Art Of the cathode ray tubes for color televisions, the Trinitron tube employs a color selection electrode different from the shadow mask used by other cathode ray tubes, and this color selection electrode is called an aperture grill. . The aperture grill is formed by etching a number of slits on a cold-rolled steel plate, then stretches it over the frame with tension applied in the slit direction, welds the edges, and in this state black at a temperature of 400-500 ° C. The product is converted into a product and incorporated into a Trinitron tube.

[0003]

The blackening treatment with steam or gas carried out in the process of manufacturing the aperture grill described above forms a dense and well-adhered oxide film on the surface, and gas generation from the inside, This is a treatment that is performed to prevent the generation of secondary electrons. However, since a thermal cycle is performed while tension is applied, the tension is lowered due to stress relaxation.
If this decrease in tension is large, the resonance frequency changes, and in the audible range, the sound of the speaker resonates, causing color shift.

For such a problem, it is conceivable that the rigidity of the aperture grill structure is increased to change the design and operation, but the sufficient effect has not been obtained.

As another measure, a method of modifying the shape of an aluminum-killed thin steel sheet before blackening treatment and performing stress relief annealing at a temperature not higher than the recrystallization temperature (Japanese Patent Laid-Open No. 61-190041),
A method using an ultra low carbon steel sheet containing 40 to 100 ppm of nitrogen (Japanese Patent Laid-Open No. 62-249339), 0.20 to 2.0% of Cr and 0.1
A method of adding a large amount of 0 to 3.0% of Mo in combination (Japanese Patent Laid-Open No. 2-17
4042).

However, in addition to the problem of increasing the number of steps, the method of removing stress before the blackening treatment does not necessarily prevent the color misregistration due to the decrease in tension due to metallurgical strengthening. The effect is not enough. Further, the method of defining only the nitrogen content has a problem that its effect is largely influenced by the content of an element having a strong affinity for nitrogen such as aluminum, and thus lacks stability. Also, a large amount of Cr,
Although the method of adding Mo is effective in preventing the tension from being lowered during the blackening treatment, it causes a change in the morphology of carbides and has a problem of poor etching processability.

The etching processability is a characteristic required as a material for an aperture grill, in addition to the fact that color shift due to a decrease in tension during blackening treatment does not occur, and further, each slit after etching process is distorted. It is also important to maintain a uniform shape. This is because if the shape of the slit is not maintained, a phenomenon called line disturbance will occur, causing color misregistration.

Regarding this etching workability, from rimmed steel which has a rim layer on the surface and is advantageous in that pickling and blackening treatment can be performed uniformly, aluminum killed steel which has few inclusions and is excellent in etching workability has been used. ing. However, as will be described later, when it is essential to reduce the amount of Sol.Al as a measure for preventing color shift due to a decrease in tension during blackening treatment, normal strong deoxidation with aluminum becomes impossible.

As described above, in order to provide all the properties required for the aperture grille, such as preventing the tension from being lowered during the blackening process that causes color misregistration, etching workability, and preventing line disturbance due to etching work. , New technology not available in the past is needed. An object of the present invention is to provide a material for an aperture grill and a method for manufacturing the same, which comprehensively solves these problems.

[0010]

Means for Solving the Problems As a result of repeated studies aimed at the above objects, the inventors of the present invention further added C, N, even if a trace amount of Cr or Mo was added in a range that does not deteriorate etching processability.
By defining Sol.Al and securing the required amount of solid solution N and C, it is possible to sufficiently prevent color shift due to tension reduction during blackening processing without degrading etching processability. I found that.

The material for the aperture grill according to the present invention and the method for producing the same will be described below.

First, the material for the aperture grill,
The present invention contains at least one or two of Cr: 0.02% or more and less than 0.20% (the same as% by weight or less), Mo: 0.02% or more and less than 0.10%, C: 0.001 to 0.030%, Si: 0.05
% Or less, Mn: 0.20 to 0.6%, P: 0.02% or less, S: 0.015%
Below, O: 0.015% or less, N: 0.0030 to 0.0120%, Sol.A
l: 0.020% or less, which satisfies the relationship shown in the following formula 1 and is characterized by containing other Fe and unavoidable impurities.

[0013]

[Equation 1] 0.1 [% Cr] + 0.1 [% Mo] + [% C] + [% N] -0.52 [% Sol.Al] ≧ 0.0100 However, [% N] -0.52 [% Sol.Al] If ≤0, set [% N] -0.52 [% Sol.Al] = 0.

Next, regarding the method for producing this material, the present invention is to cool a cold-rolled steel sheet having the above-mentioned composition into a predetermined sheet by annealing at a recovery or recrystallization temperature range below the transformation point and by secondary cold rolling. The basic feature is to make it thick.

Further, in the production process, when casting the molten metal having the above-mentioned composition, it is preferable to perform the casting by continuous casting.

The detailed reasons for each limitation will be described below.

Cr: Cr is combined with C to cause secondary hardening precipitation,
It is an important element that prevents color shift due to a decrease in tension during blackening treatment. However, if it is less than 0.02%, the effect is small, and if it is 0.20% or more, not only the effect is saturated, but also the morphology change of the carbide occurs and the etching workability is deteriorated. Therefore, its composition range is 0.02% or more and 0.20%
Less than

Mo: Mo, like Cr, is an important element that has the effect of preventing color shift due to the decrease in tension during blackening treatment,
The proper addition amount is 0.02% or more and 0.10 for the same reason as Cr.
Less than%.

C: C has the effect of ensuring strength and preventing color shift due to a decrease in tension during blackening treatment, and must be added. However, if the amount is too large, the amount of carbides increases, which causes etching processing failure, so the appropriate addition amount is 0.001 to 0.030.
%.

Si: If the amount of Si is too large, the amount of Si-based oxide increases and the etching processability deteriorates.

Mn: Mn is added for deoxidizing and imparting hot workability. If it is less than 0.20%, it has no effect, and if it exceeds 0.6%, the effect is saturated and the cost rises. Therefore, the addition range is 0.20 to 0.6%.

P: P is a strengthening element, but if its content is large, rolling performance is impaired due to factors such as grain boundary segregation.
Its content shall be 0.02% or less.

S: If the content of S is large, the amount of sulfide (MnS) with Mn increases, the etching processability deteriorates, and it causes surface defects during pickling. Therefore, the content of S is 0.015. %
The following is assumed.

O: If the content of O is large, the amount of oxides increases and the etching processability deteriorates.
0.015% or less.

When N: N exists not as a nitride but as a solid solution nitrogen, it is effective in increasing the high temperature strength and preventing the color shift due to the decrease in the tension during the blackening treatment. If the content is less than 0.0030%, no effect can be obtained regardless of the amount of Sol.Al,
Even if the content exceeds 0.0120%, the effect will be saturated, so
The content is 0.0030 to 0.0120%.

Sol.Al: Sol.Al plays a very important role. In other words, it has a strong affinity with nitrogen and forms AlN (stoichiometrically, Sol.Al fixes 0.52% of N per 1%), and is effective in preventing color misregistration due to tension reduction during blackening treatment. Not only does it lower the amount of solid solution nitrogen, but it also lowers the etching processability. Therefore, its content is 0.02
0% or less.

Here, from the basic experiment result of the present inventor, C
Has the same effect as nitrogen in the solid solution state in preventing the color shift caused by the tension decrease during the blackening treatment, regardless of whether the existing state is solid solution or precipitation. But
It was found to be comparable to 1/10 of C and N, so 0.1 [% C
r] +0.1 [% Mo] + [% C] + [% N] -0.52 [% Sol.A
It is possible to uniquely express the effect of the color misregistration countermeasure due to the decrease in tension during the blackening process with the formula l]. This formula is the essence of the present invention, and if the total amount multiplied by the coefficient of the element that can be represented by this formula is less than 0.0100, the decrease in tension during blackening processing that causes color misregistration becomes noticeable. Content of these elements is 0.1 [% Cr] +0.1 [% Mo] + [% C] + [% N]
-0.52 [% Sol.Al] ≧ 0.0100 is essential to satisfy the relationship (however, [% N] -0.52 [% Sol.A]
In the case of l] ≦ 0, [% N] −0.52 [% Sol.Al] = 0, but originally [% N] −0.52 [% Sol.Al] is preferably 0.0020 or more). Conversely, by controlling the chemical composition so as to satisfy this value, the effect of suppressing the decrease in tension during sufficient blackening treatment even with the addition of trace amounts of Cr and Mo in the range that does not adversely affect etching processability is achieved. Will be obtained.

After adjusting the molten metal having the above composition range, it is manufactured as a material for an aperture grill by casting-hot rolling-primary cold rolling-annealing-secondary cold rolling. At this time, in the present invention, casting is performed by continuous casting for the following reasons, and the temperature range is below the transformation point after the primary cold rolling.
Then, annealing is performed in the recovery temperature range or the recrystallization temperature range .

Conventionally, rimmed steel has been used for shadow masks and aperture grill materials because it can uniformly perform pickling and blackening treatment, but aluminum clean killed steel, which has a high degree of cleanliness, has few non-metallic inclusions. Is becoming available. As for the casting method, the former is an ordinary ingot making method and the latter is a continuous casting method. In the present invention, in order to improve the blackening processability by adjusting the composition, it is not necessary to use rimmed steel, and it is assumed that casting is performed by a continuous casting method that is advantageous in terms of etching processability. However, since the amount of Sol.Al is limited, it is necessary to use a method that combines light deoxidation with Mn and oxygen concentration adjustment by adding a small amount of Al, instead of the usual strong deoxidation method with aluminum.

On the other hand, in the annealing after the primary cold rolling , the temperature is below the transformation point for the purpose of stress relief and recovery is performed.
Perform in the temperature range or recrystallization temperature range . This is because if the material for an aperture grill that has been cold-rolled continuously without being annealed is photo-etched, line disturbance easily occurs due to superposition of residual stress. Further, when heated to a temperature above the transformation point, crystal grains grow and the structural homogeneity of the material is impaired, so that the etching processability deteriorates.

[0031]

[Operation] By controlling various components as described above,
It is possible to prevent a decrease in tension during blackening, which causes color misregistration. In addition to controlling the components, the continuous casting method is adopted and the annealing conditions after primary cold rolling are optimized to achieve photoetching. The property is also improved.

[0032]

[Examples] Sample materials having various compositions shown in Table 1 below were prepared.
0.25 mm in melt-degassing, continuous casting-hot rolling-cold rolling
It was made thick and continuously annealed in the recrystallization region of 650 ° C., and was made to have a thickness of 0.1 mm by secondary cold rolling, and was subjected to various evaluations mainly to investigate the influence of the chemical composition. It should be noted that only No. 19 is a rimmed steel produced by the ingot casting method, not by continuous casting, and differs from other steels in that it has a high oxygen content. As a simulation of the tension drop evaluation during the blackening treatment, a stress of 30 Kgf / mm ² was applied at 450 ° C. and the drop rate was evaluated after 5 minutes. From the results of preliminary experiments, it has been confirmed that color shift does not occur when the stress reduction rate is 10% or less. Further, etching defects and line disorder were evaluated by actually performing etching perforation. The results are also shown in Table 1 and FIG.

[0033]

[Table 1]

From these tables and drawings, the stress reduction rate is 0.
1 [% Cr] +0.1 [% Mo] + [% C] + [% N] -0.52 [%
Sol.Al] (however, if [% N] -0.52 [% Sol.Al] ≤ 0, [% N] -0.52 [% Sol.Al] = 0), there is a good correlation with this formula. If the value is 0.0100 or more, the stress reduction rate is
It turns out that it is possible to keep it below 10%. However, if 0.02% or more of at least one of Cr and Mo is not included, 0.1 [% Cr] + 0.1 [% Mo] + [% C] + [% N]
-0.52 [% Sol.Al] ≥ 0.0100 is satisfied (however, if [% N] -0.52 [% Sol.Al] ≤ 0, [% N]
-0.52 [% Sol.Al] = 0), the stress reduction rate exceeds 10% as in No.18 and No.22. Further, even if the nitrogen content is high as in Nos. 12 and 13, if the content of Sol.Al is high, the blackening processability will be poor. Regarding etching, S,
In No. 20, 21, 23, 24 with a high content of C, Cr, Mo and No. 19 with a high O content that adopted the ingot casting method instead of the continuous casting method, it was caused by inclusions and the second phase. Defects have occurred and line disturbance has occurred. On the other hand, by continuous casting, within the scope of the present invention, 0.02% or more of Cr, Mo, or both, and 0.1 [% Cr] + 0.1 [% Mo] + [% C] +
[% N] -0.52 [% Sol.Al] ≧ 0.0100 (However, if [% N] -0.52 [% Sol.Al] ≦ 0, [% N]-
Steel satisfying 0.52 [% Sol.Al] = 0) does not have the problem of color shift and etching defects due to the decrease in tension during blackening treatment.

Table 2 below shows the results obtained by changing the annealing temperature after primary cold rolling using No. 1 in Table 1 as the steel. Regarding the stress reduction rate and etching defects, the same results as in Table 1 were obtained, but regarding the line disturbance after etching, due to residual stress or non-uniformity of the structure when recovery or recrystallization annealing was not performed. , The line is disturbed.

[0036]

[Table 2]

[0037]

According to the configuration of the present invention as described above, color misregistration due to a decrease in tension during blackening treatment does not occur,
Further, it is possible to provide a material suitable for the aperture grill, which is free from the problems of defects and line disturbance due to etching.

[Brief description of the drawings]

[Fig. 1] f (Cr, Mo, C, N, Sol.
It is a graph which shows the relationship between Al) and a stress reduction rate.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication location H01J 29/07 H01J 29/07 B (72) Inventor Hiroshi Baba 1-1-1 Marunouchi, Chiyoda-ku, Tokyo No. 2 Japan Steel Pipe Co., Ltd. (72) Inventor Koichi Osawa 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Japan Steel Pipe Co., Ltd. (72) Inventor Masahiro Tsuji, Kurami Town, Takaza-gun, Kanagawa Prefecture, Japan 3 Mining Co., Ltd. In the Kurami Plant (72) Inventor Norio Yuki 3 Kurami, Sakawa-cho, Takaza-gun, Kanagawa Japan Minami Co., Ltd. Kurami Plant (72) Inventor Takeshi Masuda, Kurami-cho, Takaza-gun, Kanagawa Japan Minami Co., Ltd. Kurami Plant ( 72) Inventor Kiyoaki Nishikawa 3 Kurami, Samukawa-cho, Takaza-gun, Kanagawa Japan Mining Co., Ltd. Kurami factory inspector Satoshi Sera (5 6) References JP-A-2-174042 (JP, A)

Claims (3)

(57) [Claims] 1. The component is Cr: 0.02% or more and 0.20%
Less (less than or equal to weight%), Mo: 0.02% or more and 0.1
Contains at least one or two of less than 0%,
C: 0.001 to 0.030%, Si: 0.05% or less, Mn: 0.20 to 0.6%, P: 0.02% or less,
S: 0.015% or less, 0: 0.015% or less, N:
0.0030 to 0.0120%, Sol. Al: 0.0
A material for an aperture grill, which is 20% or less and satisfies the relation shown in the following formula 1, and further contains Fe and unavoidable impurities. ## EQU1 ## 0.1 [% Cr] +0.1 [% Mo] + [% C] + [% N] −0.52 [% Sol. Al] ≧ 0.0100 However, [% N] −0.52 [% Sol. When Al] ≦ 0, [% N] −0.52 [% Sol. Al] = 0. 2. The component is Cr: 0.02% or more and 0.20%
Or less, Mo: 0.02% or more and less than 0.10%, and at least one kind or two kinds is contained, and C: 0.001 to 0.
030%, Si: 0.05% or less, Mn: 0.20
0.6%, P: 0.02% or less, S: 0.015% or less, 0: 0.015% or less, N: 0.0030 to 0.0
120%, Sol. Al: 0.020% or less,
A cold-rolled steel sheet satisfying the relationship shown in the above mathematical expression 1 and containing Fe and unavoidable impurities is in a temperature range below the transformation point.
Annealing in the recovery temperature range or recrystallization temperature range,
Then, a method for producing a material for an aperture grill, which comprises subjecting the sheet to a predetermined plate thickness by secondary cold rolling. 3. The method for manufacturing a material for an aperture grill according to claim 2, wherein when casting the molten metal melted to have the above-mentioned component composition, the casting is performed by continuous casting. Item 2. A method for producing a material for an aperture grill according to Item 2.