WO2000070108A1

WO2000070108A1 - Material for shadow mask, shadow mask and color image receiving tube having the shadow mask incorporated therein

Info

Publication number: WO2000070108A1
Application number: PCT/JP2000/003063
Authority: WO
Inventors: Tsuneyuki Ide; Takahiko Miyazaki; Susumu Shigemasa; Yasuo Tahara; Hironao Okayama
Original assignee: Toyo Kohan Co., Ltd.
Priority date: 1999-05-12
Filing date: 2000-05-12
Publication date: 2000-11-23
Also published as: AU4432400A

Abstract

A material for a shadow mask for a color image receiving tube, characterized in that it comprises an invar alloy containing Ni in an amount of 34 to 37 wt % and inevitable trace elements, the balance being Fe, and exhibits a Vickers hardness (Hv) of 160 to 250 when it is incorporated in an image receiving tube; a shadow mask using the material; and an image receiving tube having the shadow mask incorporated therein. The material for a shadow mask is excellent in tensile strength and high temperature creep strength.

Description

Specification

Shadow mask material, shadow mask and color picture tube incorporating the shadow mask r

Technical field

The present invention relates to a shadow mask material, a shadow mask, and a color picture tube incorporating the same. More specifically, a shadow mask material for a color picture tube, which has excellent tensile strength and high temperature cleave strength, a shadow mask, and a shadow mask incorporating the same.

, 0 For color picture tubes.

Background art

The shadow mask for a color picture tube is made of Fe-36% Ni alloy-based member material or aluminum-killed steel which is a kind of ultra-low carbon steel. | (Γ In recent years, so-called flat-surface CRTs, which are welded and mounted on a frame with a slightly curved mask surface, have come to be used for shadow-mask-type empty picture tubes. CRT has a remarkable effect of remarkably reducing diffuse reflection of illumination light and the like, and reducing eye fatigue.

The shadow mask material used in such a conventional method has press moldability and shape freezing properties that maintain the shape at the time of pressing, so that it can be welded and attached to a frame with a slightly curved mask surface. It has been regarded as important.

However, when the flat surface of the cathode ray tube is further advanced in the shadow mask method, the flat surface may not be achieved on the slightly curved mask surface used in the conventional cathode ray tube. Therefore, there is a demand for the development of a shadow mask material capable of coping with a completely flat mask surface of a conventional shadow mask type i cathode ray tube. An object of the present invention is to provide a shadow mask material for a color picture tube, a shadow mask and a picture tube incorporating the same, which are capable of coping with the above-mentioned complete flat surface cathode ray tube. An object of the present invention is to provide a shadow mask material for a color picture tube having a high-temperature creep strength, a shadow mask, and a color picture tube incorporating the same.

Furthermore, after being welded to the frame, heat treatment is performed to blacken the surface.However, in order to keep the tension-imparting shadow mask after the blackening without tension loosening, the heat treatment is performed. It has been carried out at a low temperature of about 60 minutes at a temperature lower than the recrystallization temperature of steel, for example, at 45 Ot :. However, under these blackening heat treatment conditions,

It is impossible to avoid the _¾ 0 recovery phenomenon, since they produce a growth in tension applying shadow mask due to the recovery, and 4 0 gf / mm ² or more of tensile strength as a material for the tensioning shadow mask for a color picture tube, 4 5 0 ^ x 60 minutes Blackening treatment does not cause elongation, that is, it has a cleaving strength that elongation when tensile stress of 20 kgf / mm2 is disabled is 0.1% or less. Is required.

, lr Usually, it is said that the creep strength has a correlation with the material hardness.However, in the case of the tension-imparting shadow mask for a color picture tube of the present invention, it cannot be said that the creep strength is determined solely by the hardness of the material. It has been found. This is due to the unique structure of the tensioning shadow mask for a color picture tube of the present invention. As described above, the tension mask for color picture tubes of the present invention has a structure in which the outer periphery is welded to the frame, and the elasticity of the frame allows the shadow mask to be moved in one direction from top and bottom or two directions from top and bottom and left and right. Under tension. A more detailed investigation revealed that various stresses other than tension were applied to the shadow mask. As a result, it was found that, in order to simulate the material strength required for the tension-imparting shadow mask of the present invention, in addition to the hardness test, evaluation by a creep test was appropriate.

^ On the other hand, Fe-36% Ni alloy metal or aluminum-killed steel used for conventional dome-type shadow masks is hardened when shipped from a material supplier. The hardness is in the range of Weitzkers hardness (Hv) of 140 to 200 for Invar, and 160 to 240 for aluminum killed steel. These material steel sheets are first subjected to etching processing, but after a predetermined dot hole processing, the temperature is higher than the recovery or recrystallization temperature of invar material and aluminum killed steel. In this case, it is necessary to soften the material by performing annealing heat treatment. In this annealing heat treatment, when the shadow mask is press-formed into a dome shape in a subsequent press process, the shadow mask material is required to have good press formability. If the shadow mask material is hard, springback will occur after molding, it will not fit within the prescribed shape range, the distance between the phosphor surface and the shadow mask will not be kept constant when incorporated in a cathode ray tube, and eventually the color picture tube Image quality ίθ May cause deterioration. Therefore, the hardness of Fe-36% Ni alloy-based members or aluminum-killed steel used for conventional dome-type shadow masks is limited, and when it is incorporated in a cathode ray tube, the Weitzkers hardness ( H v) is approximately 150 or less. In other words, the characteristics required for the shadow mask material are the same as those of the conventional dome-type color CRT and flat surface CRT.

| (ΤTensioning shadow masks are completely different.

An object of the present invention is to solve the above problems, and an object of the present invention is to provide a tension-imparting shadow mask for a color picture tube having excellent tensile strength and high-temperature cleave strength, and a color picture tube incorporating the same. ? Disclosure of the invention

The shadow mask material according to the first embodiment of the present invention is an invar alloy containing 34 to 37% by weight of Ni and an unavoidable trace element, with the balance being Fe. It is characterized in that the hardness when incorporated into a pipe is 160 to 250 in Weitzkers hardness (Hv).

y ^ The shadow mask material according to the second aspect of the present invention is an invar alloy containing 34 to 37% by weight of Ni and an unavoidable trace element, with the balance being Fe. Big In a creep test in which a tensile stress of 20 kgf / mm ² is applied in a humid atmosphere, the creep test is performed at a temperature of 450 so that the creep strain after a holding time of 60 minutes is 0.1% or less. It is characterized by having done.

The shadow mask material according to the third embodiment of the present invention is an invar alloy containing 34 to 37% by weight of Ni and an unavoidable trace element, with the balance being Fe. In a creep test in which a tensile stress of 20 kgf Zmm ² was applied in an atmosphere, the creep strain after a holding time of 60 minutes at a temperature of 450 was 0.1% or less, and an image was received. It is characterized in that the hardness when incorporated into a pipe is 160-250 in Weitzkaers hardness (HV).

, 0 A shadow mask according to the present invention uses the shadow mask material according to any one of claims 1 to 3.

A color picture tube according to the present invention is characterized by incorporating the shadow mask of claim 4.

^ BEST MODE FOR CARRYING OUT THE INVENTION

The material used in the present invention contains 34 to 37% by weight of Ni and 0.05 to 0.40% by weight of Mn as alloying elements, and the balance consists of Fe and unavoidable impurity elements. Fe-Ni Invar alloy. This material, by managing the processing rate range of temper rolling the final step, high hardness Invar can be obtained, and even after having been subjected to blackening heat treatment after working the shadow _£) mask, Vuitsukasu hard (Hv) was found to be maintained in the range of 160 to 250.

Further, it was also found that high hardness can be maintained by controlling the working ratio of the temper rolling similarly when alloy elements other than Ni and Mn are contained.

In the case of Invar alloys containing alloying elements other than Ni and Mn, it was also found that a synergistic effect of solid solution hardening by these alloy ^ elements and work hardening by temper rolling was obtained. Hereinafter, the present invention will be described in detail.

The alloy used as a material of the shadow mask for a color picture tube according to the present invention contains 34 to 37% by weight of Ni and 0.05 to 0.40% by weight of Mn as alloying elements, and the remainder is Fe and inevitable. Consisting of impurity elements. The content of ^ ίi is in the range of the Ni content having the so-called Invar effect in the Fe—Ni binary alloy, and specifically, is preferably 34% by weight or more and 37% by weight or less.

If the Ni content is less than 34% by weight or exceeds 37% by weight, the inherent invar effect cannot be obtained, and the low thermal expansion coefficient peculiar to the invar material cannot be obtained.

Regarding Mn, λίη must be combined with S in steel and fixed as Mn S, and must be added to prevent hot brittleness and D. However, the effect of adding Mn over 0.4 wt. Since no improvement is observed, it is limited to 0.4% by weight or less.

Other unavoidable trace elements include, for example, C, S, Si and P. Each of these elements impairs the etching characteristics, and in particular, S and P embrittle the material, so it is preferable to minimize the content.

, l More specifically, each of C, S and P is preferably set to 0.01% by weight or less, and Si is preferably reduced to 0.1% by weight or less.

The invar material containing Ni and Mn used in the present invention (hereinafter referred to as Ni-Mn-based member material) is usually obtained after reducing impurity elements such as C, Si, S, and P in the melting step. Then, it is inserted into an ingot case to produce a lump, and is hot-rolled into a hot-rolled steel strip (hot coil). Next, after removing the oxide film on the surface and passing through a process in which cold rolling and subsequent annealing are combined at least once each, the hardness of the material is adjusted by surface pass rolling, and the surface roughness is imparted. Provide for etching as a material for masks.

Note that the hardness does not limit the hardness of the shadow mask material, but specifies the hardness of the shadow mask when incorporated as a shadow mask into a CRT for a color picture tube under tension. It is. Hereinafter, the shadow mask material and the method for manufacturing the shadow mask of the present invention will be described. The hardness of chamber material, which is a shadow mask material that imparts tension, is affected by the type and content of impurities, the working ratio during cold rolling, the heating conditions during annealing, and the working ratio during temper rolling. Receive strongly. For example, the working rate during cold rolling is generally in the range of 20 to 95% i, and annealing is performed in the range of 700 to 100% when using a continuous furnace, and temper rolling. Is preferably performed at a processing rate of 1 to 50%.

The higher the working ratio of cold rolling, the more the recovery and recrystallization during annealing tends to be promoted. During annealing, the softening progresses at a lower temperature and the hardness tends to decrease. The higher the annealing temperature, the more the recovery and recrystallization tend to progress.

, 0 The material softens more. The higher the working ratio of the temper rolling, the more the work hardening tends to progress, and the harder the tension imparted shadow mask material is. In addition, depending on the type and content of each impurity element in the tension-imparting shadow mask material, the higher the content of the impurities, C, Si, S and P, the higher the tension-imparting shadow mask material. Indicates a tendency to cure.

^ As described above, the material hardness of the tension-imparting shadow mask material is affected by the type and content of impurities, the working ratio during cold rolling, the temperature conditions during annealing, and the working ratio during temper rolling. Therefore, it is important to control the manufacturing conditions of the invar material for the tension imparting shadow mask in accordance with these influential factors.

The tension-imparting shadow mask for a picture tube of the present invention requires that the material hardness at the time of incorporation into a cathode ray tube be in the range of 160 to 230 in Weitzkaers hardness (Hv). In consideration of the softening due to annealing, the hardness of the material to be etched must be approximately in the range of Weitzkers hardness (Hv) 180 to 280. As the conditions, for example, the working ratio during cold rolling is set in the range of 20 to 40%, the annealing temperature is set to 700 to 800, and the working ratio during temper rolling is 3

It is desirable to set manufacturing conditions so as to be in the range of 0% to 50%. Of course, the type and content of impurities in the material for the tension-imparting shadow mask material for the picture tube It is necessary to manufacture a raw material whose amount falls within a predetermined range.

The tension-imparting shadow mask for a color picture tube according to the present invention further has an excellent cleave strength as a mechanical property. The cleave strength is the same as the hardness, the type and content of impurities, the working ratio during cold rolling, the heating conditions during annealing, and the working ratio during temper rolling.

Strongly affected by I. Therefore, it is necessary to investigate these factors in detail to satisfy the desired creep strength.

The tension-imparting shadow mask for a color picture tube of the present invention has a creep strength at the time of assembling into a cathode ray tube of 20 kgf / mm in an air atmosphere at a temperature of 450 and a creep strain of 60 minutes after a holding time of 60 minutes. Less than 1%

! 0 and required. As manufacturing conditions, for example, the working ratio during cold rolling is set to 30 to 95%, the annealing temperature is set to 700 to 800, and the working ratio during temper rolling is set to 30 to 50%. It is desirable to set appropriate manufacturing conditions. Needless to say, it is necessary to manufacture a material in which the type and content of impurities in the invar material for a tension mask for a color picture tube are within a predetermined range.

_{| (f Further} , as another embodiment, the tension-imparting shadow mask for a color picture tube of the present invention may include an alloy element other than Ν i and Μη. The alloy element is C o. Mo, Cr, T i, Nb, V, W, A1, and Cu, and at least one of them is contained, and the content is limited to the range of 0.01 to 2.0% by weight for each element.

Hereinafter, the effects of these alloy elements and the reasons for limitation will be described.

Co has the effect of further reducing the coefficient of thermal expansion of the tension imparting shadow mask of the present invention and reducing color unevenness due to the thermal expansion of the shadow mask. However, Co is an expensive element, and the upper limit is 2.0% by weight. If the content is less than 0.01% by weight, the effect is not remarkable.

^ Since Mo. Cr, Ti, Nb, V and W are remarkably solid-solution hardened and are carbide-forming elements, the precipitation hardening of carbides is combined with the tension imparted shadow mask of the present invention. The effect of increasing the hardness of the disc is remarkable. However, if each element exceeds 2.0% by weight, the precipitation amount of carbides becomes excessive and the etching characteristics are impaired. Therefore, the upper limit of these elements is set to 2.0% by weight. Conversely, if the content is less than 0.01% by weight, the solid solution effect and precipitation hardening are small.

If A 1 has a remarkable deoxidizing effect on the molten metal in the melting step, so that a clean molten metal can be obtained and, consequently, a steel sheet with few material defects can be obtained. Further, since solid solution hardening is obtained, the material can be strengthened. However, if the content exceeds 2.0% by weight, solid solution hardening becomes excessive and the etching characteristics are adversely affected. Therefore, the upper limit is set to 2.0% by weight. On the other hand, if the content is less than 0.01% by weight, the effect is not clear.

| 0 Example

Hereinafter, the present invention will be described in more detail with reference to Examples. A slab obtained by vacuum degassing and melting six types of invar materials (A to F) having the chemical compositions shown in Table 1 was hot-rolled to obtain a hot-rolled steel sheet having a thickness of 2.5 mm.

Table 2 shows that the hot rolled steel sheet in Table 1 was washed with nitric acid and then cold rolled to reduce the working rate from 20 to 85.

After rolling in the range of | l%, recrystallization annealing at a temperature of 800, and the obtained specimens with a thickness of 0.2 to 0.39 mm, the subsequent manufacturing conditions were as follows: cold rolling, annealing And conditions for temper rolling. At the same time, the hardness of the 0.1 mm thick test material, which was manufactured at the time of etching, and the characteristics of the tension-imparting shadow mask when incorporated into a Braun tube, were evaluated as the mask hardness (Witzcars hardness (Hv)) and creep elongation (atmosphere). Medium, tensile stress: 20 kgf Zmm ² , heating and holding temperature: 200 × 60 min). Chemical composition of wiping material

Characteristics of the wiping material

Specimen K-building condition 77 tinc 'r r Reinforcement when assembling round tube Remarks No.

Working rate Temperature Working rate Material hardness Hardness

(%) CC) (%) (Hv) (Hv) (%)

A1 60 800 45 220 195 0.05 The present invention

A2 90 730 50 225 198 0.04 The present invention

A3 90 800 3 158 141 0.15 Comparative example

A4 60 900 5 165 149 0.14 Comparative example

B 60 730 40 210 181 0.09 Invention

C 60 730 45 225 211 0.02 The present invention

D 60 730 45 243 228 0.01 Invention

E 60 730 45 240 225 0.01 Invention

F 60 730 45 222 206 0.03 The present invention The tension mask for a color picture tube comprising an Invar alloy containing 34 to 37% by weight of Ni and an unavoidable trace element and the balance being Fe of the present invention has high hardness and is excellent. It has high creep strength.

Further, even if the color picture tube incorporating the tension imparting shadow mask is heat-treated for blackening after being welded to the frame, the shadow mask has a small deformation amount.

The shadow mask material of the present invention is welded to a frame while applying a large tension in the vertical direction, and in a subsequent heat treatment step, the tension is applied to the shadow mask in a state where the tension is applied without loosening. It has sufficient cleave strength even at high temperatures to maintain it.

| 0 Although the shadow mask has been described in one of the upper and lower directions, the shadow mask material of the present invention is similarly sufficiently applied to a shadow mask that applies a constant tension from up, down, left, and right. It can demonstrate its function. Industrial applicability

Since the shadow mask material of the present invention has excellent tensile strength and creep strength, the shadow mask does not deform even if it is subjected to a heat treatment for blackening after being welded to the frame. It has the effect of.

Claims

The scope of the claims

1. A Nivar alloy containing 34 to 37% by weight of Ni and inevitable trace elements, with the balance being Fe. The hardness when incorporated into a picture tube is Vickers hardness i (Hv) of 160 to A material for shadow masks characterized by having a value of 250.

2. containing N i a 34 to 37% by weight and inevitable trace elements, a Invar alloy and the balance of F e, the creep test to load stress 20 kgf ZMM ² Tensile an air atmosphere, the The creep test conditions were maintained at a temperature of 450.

Material for shadow masks, characterized in that the creep distortion after 60 minutes of ID retention time is 0.1% or less.

3. N i contains 34-37% by weight and inevitable trace elements, a Invar alloy and the balance of F e, the creep test to load stress 20 kgf ZMM ² Tensile an air atmosphere, the Cleave test conditions are maintained at a temperature of 45 O.

| ΙΓ A shadow characterized by a creep strain of less than 0.1% after a retention time of 60 minutes and a hardness of 160 to 250 Vickers hardness (Hv) when incorporated into the picture tube. Material for mask.

4. A shadow mask using the shadow mask material according to any one of claims 1 to 3.> 0 5. A color picture tube incorporating the shadow mask according to claim 4.