KR0141568B1 - Alloy for manufacturing shadowmask - Google Patents

Abstract

The present invention relates to an alloy for producing a shadow mask composed of Fe and Ni.

According to the present invention there is provided an alloy for producing a shadow mask consisting of Fe and Ni; The shadow mask alloy is characterized in that it comprises 1 to 5% by weight of Cr and / or 1 to 5% by weight of Co.

According to the above configuration of the present invention, the yield strength of the Invar material consisting of Fe and Ni is lowered, so that high temperature forming process and heat treatment process are unnecessary, formability is improved, energy loss is prevented, and the defective rate of the final molded product is Is reduced.

Description

Alloy for Shadow Mask Manufacturing

TECHNICAL FIELD The present invention relates to an alloy for producing a shadow mask, and more particularly, to an alloy for producing a shadow mask, by adding Cr and Co to lower the yield strength of a material, thereby improving formability and eliminating the need for a high temperature forming process.

In general, a color picture tube (CPT) is applied to the inner surface of a panel by emitting electron beams of red, green, and blue from an electron gun and passing through a plurality of regularly arranged fine holes of a shadow mask. It takes a structure that collides with phosphors emitting red, green and blue to produce a color image. Therefore, in order to create a correct image, a number of fine holes formed in the shadow mask must be regularly and accurately aligned, and the mutual distance between the shadow mask and the inner surface of the panel must not be changed, and the curved surface is different from the inner surface of the panel. There should be no configuration changes.

As a material of the shadow mask, high purity iron is generally used as a main component, and for example, Al­kildetalan steel having a thickness of 0.1­0.3 mm is mainly used. However, as TVs become larger and higher in quality, color purity deterioration due to thermal expansion of shadow masks has become a big problem.

Therefore, in order to prevent color purity deterioration due to thermal expansion of the shadow mask, an Invar material (alloy of Fe and Ni, which has low thermal expansion coefficient and corrosion resistance) has a low thermal expansion coefficient (2.5 × 10 ⁶ ㎜ / ℃). It is used. Invar material has a thermal expansion coefficient of about one tenth of that of Al-kiltal carbon steel used in conventional shadow masks. do. However, the invar material has a high yield strength due to its material properties, which leads to considerable difficulty in molding.

In order to reduce the yield strength of the Invar material, a method of preheating the material by applying heat of about 200 ° C to the Invar material prior to molding is used. This is because the mechanical properties of the Invar material are sensitive to temperature. It is taken to improve the formability. However, the shadow mask heated by the heat transfer by the mold is not uniform in the temperature distribution and accordingly the yield stress of the Invar material becomes uneven, causing wrinkles during molding, it is difficult to maintain a constant temperature distribution of the mold This is followed by a lot of energy loss. In addition, in order to obtain a yield stress of 20 kg / mm 2, there is a problem in that a high temperature heat treatment process is required and the molding must be performed while the mold is heated.

The present invention was devised to simultaneously solve the various problems inherent in the shadow mask manufacturing alloy according to the prior art as described above, the object of the present invention is to reduce the yield stress of the material is a high temperature forming process and heat treatment process An object of the present invention is to provide an alloy for producing a shadow mask, which makes it unnecessary, improves formability, prevents energy loss, and reduces the defective rate of molded products.

According to one aspect of the invention, there is provided an alloy for producing a shadow mask consisting of Fe and Ni, the shadow mask manufacturing alloy, characterized in that 1 to 5% by weight of Cr.

According to another aspect of the invention, the shadow mask manufacturing alloy further comprises 1 to 5% by weight of Co.

According to the above characteristics of the present invention, 1 to 5% by weight of Cr and Co is included in the shadow mask manufacturing alloy, the yield strength of the Invar material consisting of Fe and Ni is lowered to form a high temperature forming process and heat treatment process This eliminates the need, improves formability, prevents energy loss and reduces the defective rate of the final molded product.

Hereinafter, preferred embodiments of the present invention will be described in detail.

The inventors of the present invention, by adding Cr to the Invar material consisting of Fe36% by weight Ni Ni reduction of the impetus defect energy and difficult to cross slip in the strain range of less than 0.2% of low dislocation density, which hinders dislocation movement It has been found that no jog is formed and yield strength is reduced. The inventors of the present invention conducted an experiment for measuring the effect on the yield strength of the material by adding Cr to the Invar material consisting of Fe ­ 36% by weight Ni.

Example 1

Cr in 1, 2, 3, and 5 wt% of Fe36 wt% Ni0.3 wt% Mn was added to dissolve the added Invar material into a thin plate, heat-treated by one-stage hydrogen annealing, and then subjected to tensile test. The results are shown in Table 1.

Referring to Table 1, it can be seen that as the addition amount of Cr increases, the room temperature (RT) yield strength after hydrogen heat treatment is significantly decreased. The yield strength when Cr is not added is about 24 kg / mm2, whereas when 3 wt% Cr is added, the yield strength is in the range of 1617 kg / mm2, and when 5 wt% Cr is added, the yield strength is 13.1 kg / mm2. Reduced to 2 mm2. The low yield strength value obtained by adding 5% by weight of Cr is almost a value close to the room temperature yield strength of the Al-kiltal carbon steel. The thermal expansion coefficient of the material to which 5 wt% Cr is added is about 4 × 10 ⁶ .

Table 1

The higher the tensile test temperature, the lower the yield strength. When tested at 100 ° C, a low yield strength of about 10.7 kg / mm2 can be obtained by adding only 1% by weight of Cr. Therefore, it is possible to mold the invar material having a thermal expansion coefficient of about 2x10 ⁶ by setting the molding temperature to 100 占 폚. Tensile strength hardly varies with the addition of Cr and decreases with increasing test temperature. It can be seen that the elongation does not show any particular change depending on the Cr content or the test temperature.

Example 2

The inventors of the present invention found that by adding Co to the Invar material composed of FeNi, the non-magnetization value is increased to lower the coefficient of thermal expansion, and Co is 1, 2, 3, After changing to 4% by weight, the added Invar material was dissolved to prepare a thin plate, heat treated by a one-stage hydrogen annealing method, and then subjected to a tensile test. The results are shown in Table 2.

Comparing the test results of the specimens 5 to 8 of Table 2 with those of the specimen 3 of Table 1, the increase in yield strength due to the addition of Co hardly occurs and the overall yield strength, tensile strength, and elongation are similar. It can be seen that. This is because the solid solution strengthening effect is almost similar to that of Co added by substituting Ni.

TABLE 2

Therefore, it can be seen that when the materials to which Cr and Co are added according to the present invention are used, it is possible to lower the heating temperature in the forming process to 100 ° C or lower.

According to the configuration as described above of the present invention, 1 to 5% by weight of Cr and Co is included in the shadow mask manufacturing alloy, the yield strength of the Invar material consisting of Fe and Ni is lowered to form a high temperature forming process and heat treatment The process is not required, the formability is improved, the energy loss is prevented and the defective rate of the final molded product is reduced.

While the invention has been shown and described with reference to certain preferred embodiments, it will be understood that the invention can be variously modified and modified without departing from the spirit or scope of the invention as set forth in the following claims. Those skilled in the art can easily know that.

Claims (2)

An alloy for producing shadow masks, which comprises Fe and Ni, comprising 1 to 5% by weight of chromium. The method of claim 1, The shadow mask manufacturing alloy, wherein the shadow mask manufacturing alloy further comprises 1 to 5% by weight of cobalt.