JPH05311327A - Material for aperture grill and production thereof - Google Patents

Abstract

(57) [Summary] [Object] To provide a material for an aperture grill, which has little etching workability and line disturbance due to etching processing, and has little color shift due to a decrease in tension during blackening treatment. [Composition] Cr: 0.02% or more and less than 0.20%, Mo: 0.02% or more and 0.
Contain at least one or two of less than 10%, C:
0.001-0.030%, Si: 0.05% or less, Mn: 0.6% over 3.0%
Below, P: 0.02% or less, S: 0.015% or less, O: 0.015% or less, N: 0.0030 to 0.0120%, Sol.Al: 0.1 at 0.020% or less
[% Cr] +0.1 [% Mo] + [% C] + [% N] -0.52 [% S
ol.Al] ≧ 0.0080 is satisfied (however, [% N] −
When 0.52 [% Sol.Al] ≤ 0, [% N] -0.52 [% Sol.A
l] = 0), other Fe and inevitable impurities.

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 etching process are small, and in addition, tension reduction during blackening treatment An object of the present invention is to provide a product having a characteristic that a 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. 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 sheet, then stretches it over the frame with tension applied in the slit direction and welds the edges. It is made into a product by subjecting it to a chemical treatment, and is incorporated into a Trinitron tube.

[0003]

The above-mentioned blackening treatment with steam or gas carried out in the process of manufacturing the aperture grill forms a dense and well-adhered oxide film on the surface to generate gas from the inside. This is a treatment that is performed to prevent the generation of secondary electrons, but since the 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 misregistration.

To solve 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 40-100 ppm of nitrogen (Japanese Patent Laid-Open No. 62-249339), 0.20-2.0% of Cr and 0.1
A method of adding a large amount of 0 to 3.0% of a composite (Japanese Patent Laid-Open No. 2-17
4042).

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

This etching processability is a characteristic that is not required for a color shift due to a decrease in tension during blackening treatment, and is a characteristic required as a material for an aperture grill. Furthermore, 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 occurs, which causes 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 characteristics required for the aperture grille, such as the prevention of tension reduction during the blackening process that causes color misregistration, the etching processability, and the prevention of line disturbance due to the etching process. , 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 solve these problems.

[0010]

Means for Solving the Problems As a result of repeated studies aimed at the above objects, the present inventors added a large amount of Mn and then added a trace amount of Cr and Mo in a range that does not deteriorate etching processability. In addition, by defining C, N, Sol.Al and securing the required amount of solid solution N and C, color misregistration caused by a decrease in tension during blackening treatment without degrading etching processability. Found that it is possible to prevent enough.

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 wt% or less), Mo: 0.02% or more and less than 0.10%, C: 0.001 to 0.030%, Si: 0.05
% Or less, Mn: 0.6% or more and 3.0% or less, P: 0.02% or less, S:
0.015% or less, O: 0.015% or less, N: 0.0030 to 0.0120%,
Sol.Al: 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] ≧ 0.0080 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 prescribed temperature range by annealing in a recovery or recrystallization temperature range below the transformation point and by secondary cold rolling. The basic feature is to make it thick.

In the manufacturing process, when casting the molten metal having the above component composition, the casting is preferably performed 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 morphological change of 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.Therefore, 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: When Mn is added in an amount of more than 0.6%, it is 450 ° C.
It is an extremely important element that significantly improves the high temperature strength in the vicinity and prevents color shift due to a decrease in tension during blackening treatment. If it is less than 0.6%, there is no effect, and if it exceeds 3.0%, the effect is saturated and the cost rises. Therefore, the addition range is over 0.6% and 3.0% or less.

P: P is a strengthening element, but if its content is large, rollability is impaired due to factors such as grain boundary segregation.
Its content is 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 a surface defect during pickling. Therefore, the content of S is 0.015. %
Below.

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 has the effect of increasing the high temperature strength and preventing color shift due to a decrease in tension during 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. That is, 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 this decrease the amount of solid-dissolved nitrogen, but it also deteriorates 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 decrease in tension during blackening, 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 measure against the color shift caused by the decrease in the tension during the blackening process with the formula l]. This formula is
It is the essence of the present invention together with Mn addition, if the total amount multiplied by the coefficient of the element represented by this formula is less than 0.0080,
Since the tension drop during blackening treatment, which causes color misregistration, becomes significant, the content of these elements is 0.1 [% Cr] + 0.1 [% Mo].
+ [% C] + [% N] -0.52 [% Sol.Al] ≧ 0.0080 It is essential that the amount be satisfied (however, [%
When N] -0.52 [% Sol.Al] ≤ 0, [% N] -0.52 [% S
ol.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 a sufficient decrease in tension during blackening treatment even with the addition of trace amounts of Cr and Mo within the range that does not adversely affect etching processability is achieved. Will be obtained. Furthermore, the effect is amplified by combining the addition of a large amount of Mn exceeding 0.6% as the constitution.

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 after the primary cold rolling, annealing is performed in a recovery or recrystallization temperature range below the transformation point.

Conventionally, rimmed steel has been used for the shadow mask and the aperture grille material because the pickling and the blackening treatment can be performed uniformly. Aluminum clean steel with high cleanliness is being used. 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 which 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 addition of a trace amount of Al, instead of the usual strong deoxidation method with aluminum.

On the other hand, the annealing after the primary cold rolling is performed in the recovery or recrystallization temperature range below the transformation point for the purpose of stress relief. This is because if the material for an aperture grill that has been cold-rolled continuously without being annealed is photo-etched, line disturbance is likely to occur 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 the decrease in tension during blackening that causes color shift, and in addition to controlling this component, adopt the continuous casting method and optimize the annealing conditions after primary cold rolling to perform photoetching. The property is also improved.

[0032]

[Examples] Sample materials having various compositions shown in Table 1 below were prepared.
0.25mm by melting-degassing, continuous casting-hot rolling-cold rolling
The thickness was continuously annealed in the recrystallization region of 650 ° C., and the thickness was 0.15 mm by the secondary cold rolling. The thickness was used for various evaluations mainly to investigate the influence of the chemical composition. It should be noted that only No. 23 is a rimmed steel produced by the ingot casting method, not by continuous casting, and is different 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 0.0080 or more, the stress reduction rate is
It turns out that it is possible to keep it below 10%. However, Mn is low like No.12 and 13, or like No.14 and 15.
0.1 [% Cr] + 0.1 [% Mo] + [% C] + [% N] − 0 if 0.02% or more of at least one of Cr and Mo is not included.
Even if the relation of 52 [% Sol.Al] ≥ 0.0080 is satisfied (however, if [% N] -0.52 [% Sol.Al] ≤ 0, [% N]-
0.52 [% Sol.Al] = 0), the stress reduction rate exceeds 10%. Also, as in No. 17, the nitrogen content is low,
Even if the nitrogen content is high, such as 18, if the Sol.Al is high, the blackening processability will be poor. Regarding etching, S, C, Cr, Mo content is high No.21,22,24,25 and O content is high No.23 adopting ingot casting method instead of continuous casting method.
In, defects caused by inclusions and the second phase occur,
The line is disturbed. On the other hand, by continuous casting,
Within the scope of the invention, while containing more than 0.6% Mn
Contains 0.02% or more of Cr or Mo, or both,
And 0.1 [% Cr] + 0.1 [% Mo] + [% C] + [% N] -0.
52 [% Sol.Al] ≧ 0.0080 (however, [% N]-
When 0.52 [% Sol.Al] ≤ 0, [% N] -0.52 [% Sol.A
Steel satisfying l] = 0) has no problem of color misregistration and etching defects due to a 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 and 8 of Table 1 as the steels. Table 1 shows the stress reduction rate and etching defects.
The same result was obtained, but with respect to the line turbulence after etching, line turbulence occurred due to residual stress or nonuniformity of the structure when recovery or recrystallization annealing was not performed.

[0036]

[Table 2]

[0037]

According to the configuration of the present invention as described above, color shift due to a decrease in tension during blackening treatment does not occur, and
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 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 (72) Inventor Yoshihiro Hosoya, Marunouchi 1-2-2, Chiyoda-ku, Tokyo Japan Steel Pipe Co., Ltd. (72) Yutaka Baba 1-2-1 Marunouchi, Chiyoda-ku, Tokyo Main Steel Pipe Co., Ltd. (72) Inventor Koichi Osawa Marunouchi 1-2-2 Marunouchi, Chiyoda-ku, Tokyo Japan Steel Pipe Co., Ltd. (72) Inventor Masahiro Tsuji 3 Kurami, Samukawa-cho, Takaza-gun, Kanagawa Japan Mining Co., Ltd In the Kurami Plant (72) Inventor Norio Yuki 3 Kurami, Sakami-cho, Takaza-gun, Kanagawa Japan Mining 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

Claims (3)

[Claims] 1. A component contains at least one or two of Cr: 0.02% or more and less than 0.20% (same as the weight% or less), Mo: 0.02% or more and less than 0.10%, and C: 0.001 to 0.030%, S
i: 0.05% or less, Mn: 0.6% to 3.0% or less, P: 0.02% or less, S: 0.015% or less, O: 0.015% or less, N: 0.0030 to 0.0
120%, Sol.Al: 0.020% or less, satisfying the relationship shown in the following formula 1, and also containing other Fe and unavoidable impurities, a material for an aperture grill. [Equation 1] 0.1 [% Cr] +0.1 [% Mo] + [% C] + [% N] −0.52 [% Sol.Al] ≧ 0.0080 However, [% N] −0.52 [% Sol.Al] If ≤0, set [% N] -0.52 [% Sol.Al] = 0. 2. The component is Cr: 0.02% or more and less than 0.20%, Mo:
Contains at least one or two of 0.02% or more and less than 0.10%, C: 0.001 to 0.030%, Si: 0.05% or less, Mn:
0.6% to 3.0% or less, P: 0.02% or less, S: 0.015% or less, O: 0.015% or less, N: 0.0030 to 0.0120%, Sol.Al:
0.020% or less, satisfying the relationship shown in the above formula 1,
A method for producing a material for an aperture grill, characterized in that a cold-rolled steel sheet containing Fe and unavoidable impurities is annealed in a recovery or recrystallization temperature range below a transformation point and is subjected to secondary cold rolling to a predetermined sheet thickness. .. 3. The method for producing a material for an aperture grill according to claim 2, wherein when the molten metal melted to have the above-mentioned composition is cast, the casting is performed by continuous casting. Item 2. A method for producing a material for an aperture grill according to item 2.