WO1998051833A1

WO1998051833A1 - Invar alloy steel sheet material for shadow mask, method of production thereof, shadow mask, and color picture tube

Info

Publication number: WO1998051833A1
Application number: PCT/JP1998/002051
Authority: WO
Inventors: Tsuneyuki Ide; Hironao Okayama; Hiroaki Ikenaga; Susumu Shigemasa; Yasuo Tahara; Taizo Sato; Akira Ikeda
Original assignee: Toyo Kohan Co., Ltd.
Priority date: 1997-05-09
Filing date: 1998-05-08
Publication date: 1998-11-19
Also published as: CN1255168A; DE19882379T1; AU7234898A; CN1083495C; MY123398A; KR100519520B1; CN1376807A; KR20010012409A; CN1132956C

Abstract

An invar alloy steel sheet for a shadow mask having improved etching characteristics, an economical method of production thereof, a shadow mask made from the invar alloy steel sheet, and a color picture tube incorporating the shadow mask. The production method is characterized by hot working a slab of an alloy consisting of 33 to 40 wt.% of Ni and the balance of Fe, applying primary cold rolling at a rolling reduction of not higher than 80 %, annealing the sheet at a temperature not lower than 550 °C, and applying further secondary cold rolling at a rolling reduction of not higher than 50 %, so that a planar integration of the {100} plane of the rolled surface is 60 to 80 %.

Description

Description Invar alloy steel sheet material for shadow mask, manufacturing method, shadow mask, and color picture tube Technical field

The present invention relates to an invar alloy steel sheet material used for a shadow mask of a color picture tube (hereinafter referred to as CRT), a method for producing the same, a shadow mask using the above-mentioned invar alloy steel sheet material, and a CRT incorporating the same. More specifically, the present invention relates to a steel plate for a shadow mask made of an Invar alloy having excellent etching properties when drilling dot holes (micro holes) of a shadow mask, a method of manufacturing the same, a shadow mask and a CRT incorporating the same. Background art

As a material for the shadow mass used in the CRT, a thin plate made of a quinvar alloy or aluminum killed steel is used. The material for shadow masks made of Invar alloy is a series of invar alloy melted, forged, hot rolled, pickled and ground, scale removed, cold rolled and annealed. It is manufactured through the following process. A flat mask can be obtained by perforating dot holes in the thin plate of Invar alloy obtained in this manner by using a photo-etching method. This flat mask is annealed, pressed into a desired shape, blackened, and then incorporated into a CRT.

The shadow mask serves as an anode for the electron beam emitted from the electron gun and as an aperture when the electron beam passing through the dot hole is applied to the fluorescent paint dot applied to the front panel. Has a combined role. The latter plays a role in directly controlling the sharpness, color bleeding, and uneven brightness of the image displayed on the CRT, The through hole requires extremely high dimensional accuracy. The dot hole is a small-diameter dot hole (hereinafter referred to as a small dot) on the cathode side of the thin mask plate, that is, the side facing the electron gun, and a large-diameter dot hole (hereinafter referred to as the panel) on the opposite side. It has a structure consisting of a small dot and a large dot, and a hole at the "meeting" portion between the small dot and the large dot (Break Through Hole, hereinafter referred to as BrTh hole ^). The Br Th hole actually plays the role of the shadow mask as an electron beam aperture.

Usually, the thickness of the alloy steel sheet for shadow mask is in the range of 100 to 250 x m, and the pitch between the centers of the dot holes is about 250 / x m in the case of the high-definition shadow mask. Further, the diameter of the Br Th hole is about 120 × m, and the Br Th hole is required to have uniform diameter / roundness and uniform circularity. In addition, the surface roughness of the etching surface is strictly required to be a dense and uniform surface in terms of the function as a diaphragm. There is a strong demand for improvements in these etching properties.

As one of concrete improvement methods, a technique for reducing impurities in an Invar alloy is disclosed in Japanese Patent Publication No. 2-51973, Japanese Patent Application Laid-Open No. 61-199023, and the like. This limits the amount of impurities such as C, 〇, and N. These proposals are minimally necessary for high-accuracy etching techniques such as shadow masks, and simply reducing impurities does not improve the etching characteristics. As a method for improving the alloy structure of an invar alloy, Japanese Patent Application Laid-Open Nos. Sho 61-93943, Japanese Patent Publication No. Hei 2-96955, and Japanese Patent Laid-Open No. Hei 6-2794946 have been proposed. It is disclosed in gazettes and the like and limits the crystal grain size or crystal orientation. In the case of polycrystalline materials, the finer the crystal grain, the less likely it is that a step is generated due to the difference in etching speed between grains depending on the crystal orientation, and it is widely known that the etching speed is uniform. This is the minimum technical content required to improve Further, the invar alloy has a face-centered cubic crystal structure, and has exactly the same kind of crystal structure as austenitic stainless steel, which is well known as a stainless alloy in the field of steel materials. That is, in the case of the face-centered cubic material, etching is performed on the {111} plane and the {100} plane. It is a long-known technique to progress more uniformly on a surface with such a high atomic density.

Thus, it cannot be said that the combination of the conventional techniques alone has yet provided etching characteristics that can be used for a high-definition shadow mask. Furthermore, in order to industrially produce a fine grain structure and crystal orientation structure, complicated adjustments such as cold rolling and annealing are required, which is a major factor in cost increase. I have. Recently, there has been a strong demand for cost reduction of shadow masks, and there is a need for shadow masks and mask materials that are compatible with high definition and that are less expensive.

In view of the above, the present invention provides an industrially inexpensive provision of an invar alloy steel plate as a material for a shadow mask having even better etching characteristics, a method of manufacturing the invar alloy steel plate, and a method of manufacturing the invar alloy steel plate. An object of the present invention is to provide a shadow mask using the same and a color picture tube incorporating the shadow mask. Disclosure of the invention

! 5 What is the Invar alloy steel plate material for shadow mask of claim 1? ^ Is 33 to 40% by weight, and the balance is Fember, which is a member material of a steel alloy for shadow masks, and the degree of integration of the {100} plane of the rolled surface is 60 to 80%. It is characterized by.

The method for producing a steel member material for a shadow mask according to claim 2 is characterized in that, after hot working a slab of an alloy having Ni of 33 to 40% by weight and the balance of Fe, the reduction rate is 80%. It is characterized by performing the following primary cold rolling, followed by annealing at 550 ° C. or more, and then performing secondary cold rolling at a reduction of 50% or less.

In such a production method, the rolling reduction in the primary cold rolling is desirably 50 to 80% (Claim 3), and the temperature range in the annealing is 65 to 95 ° C. (Claim 4), and the rolling reduction in the secondary cold rolling is preferably 0.055 to 40% (claim 5).

6. The shadow mask for a color picture tube according to claim 5, wherein It is characterized by using a mono-alloy steel plate material.

A color picture tube according to a sixth aspect is characterized in that the color picture tube shadow mask is incorporated. BEST MODE FOR CARRYING OUT THE INVENTION

First, the Ni content in the Invar alloy is limited to the range of 33 to 40% by weight. When the Ni content is in this range, the coefficient of thermal expansion is significantly reduced, and even when incorporated into the CRT, image distortion and color unevenness do not occur due to temperature changes. On the other hand, if the Ni content is less than 33% by weight or exceeds 40% by weight, the coefficient of thermal expansion increases, and the above-mentioned problems such as distortion occur. A technical problem in the production of Invar alloy steel sheets used for CRT shadow masks is the improvement in etching characteristics of Invar alloys. However, in industrial production, the production conditions are severe because priority is given to improving the properties of invar materials, and the production process is only becoming more complicated. To improve the etching characteristics of the Invar alloy within the industrially feasible range, it is necessary to set the {10} 50} plane integration degree in the range of 60 to 80%. When the degree of integration exceeds 80%, the effect of improving the etching characteristics is small, but rather, the rolling reduction increases in the cold rolling process, which unnecessarily increases the number of passes and increases the rolling time. Come delay. Furthermore, the cost will increase due to the wear of the rolling rolls due to the work hardening of the Invar alloy steel sheet. Also, etching equipment for shadow masks

2-0 has been significantly improved in recent years, and the high-temperature etchant is sprayed at high pressure. Good etching conditions are being prepared compared to the conditions. Therefore, it is necessary to limit the upper limit of the {100} plane integration of the Invar alloy to about 80%, and to propose manufacturing conditions that can cope with the reduction of the shadow mask price to some extent. On the other hand, if the degree of {100} plane integration falls below 60%, the etching characteristics deteriorate, so the lower limit is limited to 60%. Based on the above concept, a method for manufacturing an Invar alloy steel sheet will be described below in order to set the degree of integration of the {100} plane to 60 to 80%. Melt Ni to 33 to 40% by weight and the balance to Fe, and manufacture it in an ingot and then manufacture it, or create a slab with continuous manufacturing equipment and then hot-work to segregate components? And processing into a hot coil. The oxide scale on the surface is removed by pickling or grinding with a grindstone. Hereinafter, the steel sheet is finished through primary cold working, annealing, and secondary cold working. The primary cold working usually uses a cold rolling method using a rolling mill. The reduction is not only an important factor in the rolling structure of Invar alloys, but also important in the cost required for cold rolling. According to the present invention, as a result of various tests, the rolling reduction in the first cold rolling jo is set to 80% or less. More preferably, it is limited to the range of 50 to 80%. If the rolling reduction is less than 50%, the degree of integration of the {100} plane cannot be satisfied, and it falls below the lower limit of the degree of integration of {100}, 60%. Conversely, even if the rolling reduction exceeds 80%, the degree of increase in the {100} plane integration is small, and not only does the load of the rolling process increase unnecessarily, but also the wear of the roll increases rapidly. The upper limit of rolling reduction is limited to 80% at f5. The annealing in the next step is aimed at recovering the rolled structure and recrystallization, and its temperature range is 550 ° C or higher. The degree of integration of the {100} plane is increased by this annealing treatment. If the temperature is out of this temperature range and lower than 550 ° C., desired recrystallization does not proceed, and the {100} plane integration degree is significantly reduced. On the other hand, if the temperature exceeds 950 ° C, recrystallization progresses remarkably and the crystal grains become coarse, resulting in a decrease in etching characteristics. A more preferable temperature range is 650 to 950 ° C. The secondary cold working aims to increase the hardness and strength by work hardening, and imparts a predetermined hardness to the Invar alloy steel sheet while maintaining the high degree of {100} plane integration obtained by annealing. . Therefore, the rolling reduction range of the secondary cold processing is 50% or less. If the rolling reduction exceeds 50%, the high degree of integration of the {100} plane due to annealing will disappear, and the annealing effect will be lost.

I The draft in secondary cold working should be 50% or less. More preferably, it is set to 0.05 to 40%. If it is less than 0.05%, there is no difference in hardness with the annealed material, and the effect of secondary cold working It is not allowed. As a result, the hardness and the strength of the Invar alloy steel plate are insufficient, so that a process trouble due to bending of the plate or the like easily occurs at the time of the passing operation in the etching process. Usually, the hardness required for the Invar alloy is Vitzkaas hardness Hv 130 or more, and the hardness of the Invar alloy steel sheet of the present invention is in the range of Hv 130 to 250. Furthermore, the thus obtained invar alloy steel sheet for a shadow mask was quantitatively evaluated for the {100} plane integration degree by an X-ray diffraction method. After measuring the diffraction intensities of the {1 1 1}, {100}, {1 10} and {31 1} planes,

{100} surface integration (%) = 100 X {100} no [{1 1 1} + {100}

+ {1 10} + {31 1}] ··· (1) f0 The {100} plane integration was calculated by the calculation method represented by the above equation (1). Here, {111}, {100}, {110} and {311} represent the diffraction intensity of each plane. Next, the etch factor was used as a quantitative evaluation method of the etching characteristics. One method of measuring the etch factor is to etch one side of the steel sheet and determine the ratio of the etch depth to the side etch.

, ₅ Etch factor 1 = (etch depth) / (side etch) · · · (2) As shown in the above formula (2), for materials with excellent etching characteristics, the etch depth (the thickness direction by liquid spray) The side etch (etch length in the plate surface direction) is smaller than the etch length, and the etch factor is high. Conversely, a material having poor etching characteristics has a large side etch and a small etch factor. 0 The mechanical properties of the materials were compared by measuring the hardness of the materials. The hardness was measured using a Vickers hardness tester with a weight of 100 g.

(Example)

Hereinafter, the present invention will be described in more detail with reference to Examples. A hot coil was prepared through melting, forging, forging, homogenizing heat treatment, hot rolling, and pickling steps of an Invar alloy steel sheet having the chemical composition shown in Sample No. A in Table 1. Table 2 shows the production conditions for primary cold rolling, annealing and secondary cold rolling. Table 3 shows the characteristics of the materials obtained. Is shown. The hardness is represented by Vickers hardness (Hv—100), and a value of 130 or more is regarded as “OK”. In an etching line, a steel sheet is usually passed in a strip shape, so that the steel sheet cannot be normally passed on the line unless the Weiss force hardness is 130 or more. The degree of integration means the degree of {100} plane integration, and 50 to 80% is regarded as acceptable. The {100} plane integration is determined by the X-ray diffraction method described above. An etch factor of 2.6 or more is considered acceptable. In the table, 〇 means “possible” and X means “impossible”.

The samples No. 7 to 10 of the examples of the present invention satisfy the criteria for the material properties, while the samples No. 7 to 10 of the comparative examples have the hardness, the degree of integration or the etch factor. It can be seen that one or more do not satisfy the criteria. Industrial applicability

The invar alloy steel sheet material for a shadow mask of the present invention comprises a primary cold-rolled steel having a reduction ratio of 80% or less after hot-working a slab of an alloy having a Ni content of 33 to 40% by weight and a balance of Fe. Rolling, then annealing at 550 or more, and further performing secondary cold rolling with a reduction of 50% or less, it is possible to manufacture at low cost, and it has good etching characteristics. I have. A color picture tube incorporating a shadow mask using this shadow mask material has little color bleeding and uneven brightness, and is excellent in the sharpness of the projected image.

'9S ειο'ο wo'o 100 "0 00 · ο L000 -0 100 · 0 zz · 0 ozo · 0 · 0 V ϊ N 1 V 1 N S d! S 3 ON

(96 honors) 3Ϊ

lSOCO / 86Jf / X3d Table 2

Manufacturing conditions for monoalloy copper sheets

Trial manufacturing conditions

Material Primary cold rolling m Pure Secondary cold rolling

No Front thickness Back thickness Reduction rate Temperature time Rear thickness Reduction rate f, r, fme, f,

(mm;, mm) (%) (min) mm) (%)

1 0.49 0.230 53.0 800 5 0, 200 13.3

2 0.70 n ten 78.5 800 5 0.130 13.3

3 1 no υon η ουυ ς n on

3 u. U

4 0.65 0.131 80.0 800 5 0.130 0.2

5 0.70 0.150 78.5 670 5 0.130 13.3

6 0.70 0.150 78.5 940 5 0.130 13.3

7 2.60 0.130 95.0 1000 5

8 1.73 0.260 85.0 1000 5 0.130 50.0

9 0.70 0.150 78.5 500 5 0.130 13.3

10 0.31 0.186 40.0 800 5 0.130 30.0 Characteristic evaluation results

Material characteristics

(100)

IS degree factor

No

tlV-one 1WU

1 1 c 1 c OnU 2.8 o The present invention

2 1 n CO

13U 00 2.7 o The present invention

3 ISO 62 2.7 〇 The present invention

4 145 79 2.8 発明 The present invention

5 172 67 2.7 発明 The present invention

6 139 71 2.7 〇 The present invention

7 116 98 2.6 X Comparative example

8 196 58 2.4 X Comparative example

9 179 52 2.5 X Comparative example

10 180 46 2.4 X Comparative example

Claims

The scope of the claims

1. Invar alloy steel sheet material for shadow masks consisting of 33 to 40% by weight with> 11 and the balance Fe, characterized in that the {100} plane integration of the rolled surface is 60 to 80%. Invar alloy steel plate material for shadow masks.

2. After hot-working an alloy slab consisting of 33% to 40% by weight of 1 ^ 1 and the balance of Fe, the steel is subjected to primary cold rolling at a reduction of 80% or less, and then annealed at 550 or more. A method for producing an invar alloy steel sheet material for a shadow mask, further comprising performing a secondary cold rolling at a rolling reduction of 50% or less.

3. The method for producing an invar alloy steel sheet material for a shadow mask according to claim 2, wherein a reduction ratio in the first cold rolling is 50 to 80%.

4. The method according to claim 2, wherein a temperature range of the annealing is 650 to 950.

5. The rolling reduction in the secondary cold rolling is 0.05 to 40%.

3. The method for producing an invar alloy steel sheet material for a shadow mask according to claim 2, wherein

6. A shadow mask for a color picture tube, wherein the invar alloy steel plate material for a shadow mask according to claim 1 is used.

7. A color picture tube, wherein the shadow mask for a picture tube according to claim 6 is incorporated.