JPH10259454A - Ferrum-nickel base alloy sheet excellent in etching pierceability - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an Fe-Ni base alloy sheet excellent in etching pierceability, in an Fe-Ni base alloy sheet for a shadow mask, by specifying the total content of oxide inclusions and furthermore specifying the weight ratio of MgO/Al2 O3 in the region. SOLUTION: In an Fe-Ni base alloy sheet for a shadow mask, the content of oxide inclusions is regulated to <=0.003 wt.% expressed in terms of oxygen, and the weight ratio of MgO/Al2 O3 in the oxide inclusions in this region is also regulated to >=0.25, preferably, to >=0.4. This Fe-Ni base alloy is, e.g. composed of, by weight, <=0.005% C, <=0.4% Si, 0.1 to 1% Mn, 30 to 45% Ni, <=0.1% Cr, <=0.003% O, <=0.005% S, <=0.005% N, 0.001 to 0.2% Al, and the balance substantial Fe. Furthermore, among the oxide inclusions, the weight ratio of the oxides other than MgO and Al2 O3 is regulated to <=20%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an Fe-Ni alloy for a shadow mask having excellent etching piercing properties, and more particularly to an Fe-Ni alloy having improved etching piercing properties by controlling the composition of an oxide-based inclusion. Related to an alloy plate.

[0002]

2. Description of the Related Art Heretofore, cold rolled Fe—Ni alloys as shadow mask materials for high-definition TVs have been required to have a low expansion coefficient and to be free from defects during etching perforation.

[0003] Since many defects generated at the time of etching drilling are caused by oxide-based inclusions, there are various methods for controlling the composition, shape, size, and amount of oxide-based inclusions in an Fe-Ni-based alloy plate. Proposed.

In Japanese Patent Application Laid-Open No. 63-231844, the width of the non-metallic A-type inclusions in the cross section and the surface parallel to the rolling direction of the shadow mask is 5.0 μm by the JIS method.
m or less, a length of 50 μm or less, a width of the granular inclusion aggregate of B-based nonmetallic inclusions of 5.0 μm or less, a length of 50 μm or less, and an average diameter of a single inclusion of C-based nonmetallic inclusions of 5 μm or less. 0.0μ
m or less, the value of d (A + B + C) 60X400 is 0.01
It has been proposed to reduce the occurrence of defects at the time of etching perforation by using a steel plate manufactured from an Fe-Ni-based alloy plate having the following cleanliness.

In Japanese Patent Application Laid-Open No. 62-161936, non-metallic inclusions contained in a cold rolled Fe—Ni alloy for a shadow mask are shown in FIG. 3 as Al ₂ O ₃ —MnO—Si.
Points in O ₂ ternary system phase diagram _{1: Al 2 O 3: 4wt} % MnO: 58wt% SiO 2: 38wt% points _{2: Al 2 O 3: 5wt} % MnO: 49wt% SiO 2: 46wt% point 3: _{Al 2 O 3: 23wt% MnO} : 23wt% SiO 2: 54wt% points _{4: Al 2 O 3: 27wt} % MnO: 31wt% SiO 2: 42wt% points _{5: Al 2 O 3: 17wt} % MnO: 54wt% SiO A method has been proposed for reducing the occurrence of defects at the time of etching perforation by making the composition in a region surrounded by a line connecting ₂ : 29 wt% sequentially.

[0006]

However, with the trend toward higher definition of color televisions and the increase in the use of shadow masks in personal computers, the demand for higher definition of shadow masks has been further increased. F applied
Even with an e-Ni-based alloy cold-rolled sheet, it has become impossible to suppress defects at the time of etching perforation caused by inclusions. Therefore, there is no defect at the time of etching perforation, which is a problem with respect to the currently required high definition.
An e-Ni alloy cold rolled sheet has not yet been proposed.

[0007] It is naturally effective to reduce the amount of inclusions as much as possible in order to suppress the occurrence of defects at the time of etching perforation. However, further reduction of inclusions from the current level leads to a considerable increase in manufacturing cost. , Not realistic.

The present invention has been made in view of the above circumstances, and has no defects at the time of etching perforation, and can be used for a shadow mask for a high-definition color television and a personal computer. It is an object of the present invention to provide an Fe-Ni-based alloy plate having excellent properties.

[0009]

Means for Solving the Problems The present inventors have intensively studied to solve the above problems. As a result, it has been found that there is an extremely strong correlation between the hole shape abnormality and the linear defect generated at the time of etching and the composition of the oxide-based inclusions in the steel sheet.

That is, an Fe—Ni alloy applied to a shadow mask or the like is usually refined in an electric furnace,
D (vacuum-arc degassing), VOD (vacuum-oxygen decarburization) can be obtained by cracking, hot rolling, cold rolling the ingot after refining, or after exiting the converter. It is obtained by hot rolling and cold rolling a slab obtained by continuously casting molten steel obtained by adjusting the components in the secondary refining, but is included in the finally obtained Fe-Ni alloy plate. It has been found that by controlling the composition of the oxide-based inclusions, it is possible to prevent defects generated at the time of etching perforation.

The present invention has been made based on such findings, and the content of oxide-based inclusions is 0.003% by weight or less in terms of oxygen, and the MgO / Al ₂ O ₃ weight ratio is 0.1%. An object of the present invention is to provide an Fe—Ni-based alloy plate excellent in etching piercing property, which is characterized by being 25 or more.

Further, in the above invention, there is provided an Fe—Ni-based alloy plate excellent in etching piercing property, wherein the weight ratio of MgO / Al ₂ O ₃ in the oxide-based inclusions is 0.4 or more. To provide.

Further, in any one of the above inventions, the proportion of oxides other than MgO and Al ₂ O ₃ among oxide-based inclusions is not more than 20% by weight.
An object of the present invention is to provide an e-Ni-based alloy plate.

Further, in any of the above inventions, the ratio of oxide-based inclusions can be determined by dissolving a sample, extracting only oxide-based inclusions, and quantitatively analyzing a metal element from the extract. It is intended to provide an Fe-Ni-based alloy plate characterized by the following.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. First, the actual state of hole-shaped abnormalities and linear defects generated during etching was investigated. Almost all of the inclusions present at this site were oxide-based inclusions mainly composed of Al ₂ O ₃ , and had a size of about several μm to several tens μm. The present inventors conducted an investigation based on the above findings, focusing on the relationship between the composition of oxide-based inclusions contained in the material and the defect rate.

First, etching drilling was carried out in a laboratory using cold rolled Fe—Ni alloys for shadow masks manufactured under various conditions. In the case of etching perforation in a laboratory, if the etching defect rate is 1% or less, there is no problem in an actual etching line.

Next, about 5 g of a sample was sampled from the cold-rolled plate subjected to the etching perforation, dissolved in a 10% Br ₂ -methanol solution to extract inclusions, and the inclusions after the extraction were quantified. Originally, besides oxide inclusions in steel,
Sulfide-based inclusions, carbide-based inclusions, and nitride-based inclusions are included, and methods for extracting these inclusions include acid dissolution, halogen-organic solvent dissolution, and electrolytic extraction. Of these inclusions, the oxide-based inclusions that affect the etching piercing property, it is necessary to selectively extract only the oxide-based inclusions in the Fe-Ni-based alloy, and the extracted It is necessary to quantify the inclusions, and for that purpose, acid dissolution extraction and halogen-organic solvent extraction are suitable.

FIG. 1 shows MgO / Al in oxide-based inclusions.
The relationship between the ₂ O ₃ weight ratio and the etching failure rate is shown. The oxide-based inclusions are mainly composed of Al ₂ O ₃ and MgO, and are composed of a small amount of SiO ₂ , CaO, MnO and the like.
It is confirmed that the / Al ₂ O ₃ ratio has a very strong correlation with the etching failure rate.

That is, in the region where the total amount of oxide-based inclusions is 30 ppm or less (0.003 wt% or less) in terms of oxygen, the defect rate is 1% or less when the MgO / Al ₂ O ₃ weight ratio is 0.25 or more. And 0.4
If it is 0 or more, no defect occurs. FIG. 2 shows Al ₂ O ₃
A MgO binary system phase diagram is shown, from which the MgO /
When the Al ₂ O ₃ weight ratio is 0.25 or more, the inclusion composition in the equilibrium state is Spinel or Spinel + P
It can be seen that this is an ericrose area.

On the other hand, when the weight ratio of MgO / Al ₂ O ₃ is 0.2
In the range lower than 5, the defective rate exceeds 1%. As apparent from the phase diagram of FIG. 2, this region is a region in which the inclusion composition in the equilibrium state is Corundum + Spinel or Corundum.

Based on these results, in the present invention, the total amount of the oxide-based inclusions is set to 30 ppm or less in terms of oxygen, and from the viewpoint of suppressing the etching failure rate to a level having no problem in an actual etching line. In the above, the weight ratio of MgO / Al ₂ O ₃ in the oxide-based inclusions was set to 0.
25 or more. If the weight ratio is 0.40 or more, no etching failure occurs at all, so the MgO / Al ₂ O ₃ weight ratio is more preferably 0.40 or more.

As described above, by defining the total amount of the oxide-based inclusions and the weight ratio of MgO / Al ₂ O ₃ therein, the occurrence of defects at the time of etching drilling can be suppressed. By reducing the proportion of oxides other than MgO and Al ₂ O _{3 in} the material and setting the weight ratio to 20% or less, the etching piercing property can be further improved.

In the present invention, in order to determine the ratio of the oxide-based inclusions, it is preferable to dissolve the sample, extract only the oxide-based inclusions, and quantitatively analyze the metal element from the extract. Although it is possible to quantify it from a scanning electron micrograph or the like, the analysis accuracy is higher when the sample is dissolved and the oxide-based inclusions are extracted. In this case, the amount of the sample is preferably 1 g or more. As the method for extracting the oxide-based inclusions, the above-described acid dissolution extraction and halogen-organic solvent extraction are suitable, and it is preferable to use any of these methods.

In the present invention, etching defects are prevented by controlling the composition of the oxide-based inclusions after reducing the amount of the oxide-based inclusions to a certain extent as described above. Etching defects can be prevented without reducing the amount of system inclusions, and an Fe-Ni-based alloy plate with low etching defects can be obtained at low cost.

In the present invention, the alloy composition other than the total amount and the ratio of the oxide inclusions is not particularly limited.
-Ni-based alloy, for example, by weight%, C: 0.
005% or less, Si: 0.4% or less, Mn: 0.1 to 1
%, Ni: 30 to 45%, Cr: 0.1% or less, O:
0.003% or less, S: 0.005% or less, N: 0.0
It is possible to use an Fe-Ni-based alloy containing 0.05% or less, Al: 0.001 to 0.2%, and the balance substantially Fe. In addition, a material in which a part of Ni is replaced by up to 6% by weight of Co can be used. In addition, the effects of the present invention are not impaired even if alloy elements such as Ca and Mg are added as necessary.

Regarding the production method, steel adjusted to a predetermined composition by a converter and secondary refining may be used as a slab by continuous casting, or may be refined in an electric furnace,
A steel smelted by AD (vacuum-arc degassing) or VOD (vacuum-oxygen decarburization) may be formed into a slab by ingot cracking and rolling after ingot casting.

The slab thus obtained is subjected to hot rolling, cold rolling, etc., according to a conventional method, so that a slab having a predetermined thickness is obtained.
It is an e-Ni alloy plate. Specifically, for example, the slab is hot rolled, pickled, cold rolled, annealed, and cold finish rolled to obtain a product.

[0028]

EXAMPLE An electric furnace, a VAD furnace (vacuum-arc degassing furnace) and a VOD furnace (vacuum-oxygen decarburizing furnace) were used.
0.005% or less, Si: 0.4% or less, Mn: 0.1
１1%, Ni: 30 to 45%, Cr: 0.1% or less,
O: 0.003% or less, S: 0.005% or less, N:
0.005% or less, Al: 0.002 to 0.03%, Fe-Ni-based alloy consisting of the balance Fe and unavoidable impurities was dissolved to adjust the components, and cast to obtain a steel ingot. The ingots were subjected to hot rolling, pickling, cold rolling, annealing, and cold finish rolling to obtain a 0.13 mm-thick steel sheet for a shadow mask. At this time, the composition of the oxide-based inclusions was variously changed by adjusting the amount of the deoxidizing agent, the slag composition, the refining conditions, and the like.

A sample for inclusion measurement was collected from the steel sheet,
About 5 g is dissolved in a 10% Br ₂ -methanol solution to extract oxide inclusions, determine the amount of the extracted oxide inclusions, determine the MgO / Al ₂ O ₃ ratio in the inclusions, The proportion of oxides other than MgO and Al ₂ O _{3 in the} system inclusions was determined.

At the same time, the steel plate was subjected to etching perforation in a shadow mask, the defect rate such as abnormal hole shape or linear defect was investigated, and the amount of oxide-based inclusions in terms of oxygen and the amount of M in the inclusions were determined.
gO / Al ₂ O ₃ ratio and Mg in oxide-based inclusions
The evaluation was made in accordance with the ratio of oxides other than O and Al ₂ O ₃ . Table 1 shows the results.

Comparative Examples 1 and 2 are examples in which the rate of defective etching is high because the amount of oxide-based inclusions exceeds 30 ppm in terms of oxygen. In Comparative Examples 3 and 4, the amount of oxide-based inclusions was 30 ppm or less in terms of oxygen, but MgO / Al ₂
This is an example in which the etching failure rate is high because the O ₃ ratio is 0.25 or less. In Comparative Examples 5 and 6, both the amount of the oxide-based inclusions and the ratio of MgO / Al ₂ O ₃ are out of the range of the present invention, and the etching failure rate is particularly high.

On the other hand, in Examples 1 to 11 which are within the scope of the present invention, it can be seen that the defective etching rate is low and good etching properties are obtained. Above all, M
gO / Al ₂ O ₃ weight ratio is 0.4 or more and Mg
20% by weight of oxides other than O and Al ₂ O ₃
The following Examples 1 to 4 and 7 to 9 all had an etching failure rate of 0.

[0033]

[Table 1]

[0034]

As described above, according to the present invention,
By reducing the amount of oxide inclusions to some extent and defining its composition in a specific range, it can be used for shadow masks for high-definition color televisions and personal computers, and has excellent etching piercing properties. A Ni-based alloy plate can be obtained at low cost. Therefore, by applying the present invention, it is possible to reduce etching defects such as hole-shaped abnormalities and linear defects caused by oxide-based inclusions without extremely reducing oxide-based inclusions. While at a cost, the ability to etch perforations can be significantly improved.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the amount of oxide-based inclusions in terms of oxygen, the weight ratio of MgO / Al ₂ O _{3 in} oxide-based inclusions, and the etching failure rate.

FIG. 2 is an Al ₂ O ₃ —MgO binary system phase diagram.

FIG. 3 shows Al ₂ O ₃ —MnO ₃ —S showing the region of the composition of oxide-based inclusions present in a conventional Fe—Ni-based alloy steel sheet.
iO ₂ ternary phase diagram.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tsuneo Kondo 1-2-1, Marunouchi, Chiyoda-ku, Tokyo, Japan Inside Nihon Kokan Co., Ltd. (72) Inventor Tomohiko Uchino 1-2-1, Marunouchi, Chiyoda-ku, Tokyo, Japan (72) Inventor Akira Yamamoto 1-1-2, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd.

Claims (4)

[Claims] 1. The method according to claim 1, wherein the content of the oxide-based inclusion is 0.003 wt% or less in terms of oxygen, and the content of Mg in the oxide-based inclusion is
_{O / Al 2 O 3 Fe-} Ni alloy plate having excellent etching perforated, wherein the weight ratio is 0.25 or more. 2. MgO / Al ₂ in the oxide-based inclusions
O ₃ wherein the weight ratio is 0.4 or more, Fe-Ni alloy plate having excellent etching perforation of claim 1. 3. The method according to claim 1, wherein the proportion of oxides other than MgO and Al ₂ O _{3 in} the oxide-based inclusions is not more than 20% by weight. Fe-Ni alloy plate with excellent etching piercing property. 4. The ratio of oxide inclusions is determined by dissolving a sample, extracting only oxide inclusions, and quantitatively analyzing a metal element from the extract. The Fe-Ni-based alloy plate according to any one of claims 1 to 3, wherein the Fe-Ni-based alloy plate has excellent etching piercing properties.