JP2565058B2 - Fe-Ni alloy cold rolled sheet for shadow mask excellent in blackening processability and method for producing the same - Google Patents

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 cold-rolled sheet for a shadow mask, which is used for a cathode ray tube of a color television and has excellent blackening property, and a method for producing the same.

[0002]

2. Description of the Related Art Cold-rolled low carbon steel sheets have hitherto been used as materials for shadow masks used in cathode ray tubes of color televisions. However, the shadow mask made of low-carbon steel cold-rolled sheet has a problem that the relative positional relationship between the shadow mask and the fluorescent screen is deviated due to the deformation caused by thermal expansion during use, resulting in color misregistration. there were.

In recent years, as the quality of color televisions has increased, the above-mentioned color shift has become a problem. As a material for a shadow mask capable of preventing the color shift, 34 to 38 wt.% Is used.
Fe-Ni alloy cold-rolled sheets containing nickel have been used. The coefficient of thermal expansion of Fe-Ni alloy cold rolled sheet is
Remarkably lower than low carbon steel cold rolled sheet. Therefore, if a shadow mask made of a Fe-Ni alloy cold rolled sheet is used, it is possible to prevent the occurrence of color shift due to its thermal expansion.

Such an Fe-Ni alloy cold-rolled sheet for a shadow mask material having a low coefficient of thermal expansion is disclosed in JP-A-62-161,93.
A Fe-Ni alloy cold-rolled sheet disclosed in Japanese Patent No. 6 which has excellent surface properties during cold rolling and essentially consists of the following has been proposed. Nickel: 30 to 45 wt.%, Manganese: 0.3 to 1.0 wt.%, Silicon: 0.1 to 0.3 wt.%, Aluminum: 0.0004 to 0.0020 wt.%, And the rest,
Iron and inevitable impurities (hereinafter referred to as "prior art").

[0005]

The above-mentioned prior art has the following problems. That is, the shadow mask is
In order to promote heat dissipation and prevent rust, it is necessary to form a black oxide film (hereinafter referred to as a blackened film) on the surface thereof. However, in the Fe-Ni alloy cold-rolled sheet of the prior art, silicon oxide is generated due to the fact that it contains 0.1 to 0.3 wt.% Of silicon. As a result, it is not possible to form a blackened film having uniform blackness without unevenness and excellent heat radiation performance and adhesiveness, and thus the blackening processability is poor.

From the above, it is possible to form a blackening film having a uniform blackness without unevenness and having excellent heat radiation performance and adhesion, and a shadow mask material having excellent blackening processability. Fe-Ni alloy cold-rolled sheet for steel is required,
Such alloy cold-rolled sheet and its manufacturing method have not been proposed yet.

Therefore, an object of the present invention is to solve the above-mentioned problems and to form a blackened film having uniform blackness without unevenness and excellent heat radiation performance and adhesion.
An object of the present invention is to provide an Fe—Ni-based alloy cold-rolled sheet for a shadow mask material, which is excellent in blackening processability, and a manufacturing method thereof.

[0008]

SUMMARY OF THE INVENTION From the above-mentioned viewpoints, the inventors of the present invention have proposed a black mask material excellent in blackening processability.
To develop Fe-Ni alloy cold rolled sheet and its manufacturing method,
We have earnestly studied. As a result, the following findings were obtained. That is,
An Fe-Ni-based molten alloy containing nickel in the range of 34 to 38 wt.% Was prepared, and oxygen was supplied to the Fe-Ni-based molten alloy in an electric furnace and / or a ladle to produce the Fe-Ni-based molten alloy. -Ni
Silicon, chromium, contained in the molten alloy
Titanium, tungsten, niobium, vanadium and boron are oxidized, the generated oxide is absorbed by CaO 2 slag and removed. It was found that an Fe-Ni alloy cold-rolled sheet for a shadow mask material having excellent processability can be obtained.

The present invention has been made based on the above-mentioned findings, and the Fe-Ni alloy cold-rolled sheet for a shadow mask excellent in blackening treatment of the present invention essentially consists of the following. ing. Nickel: 34 to 38 wt.%, Manganese: 0.05 to 0.35 wt.%, Aluminum: 0.001 to 0.020 wt.%, Silicon: 0.05 wt.% Or less, Chromium: 0.05 wt.% Or less, Titanium: 0.02 wt.% Or less However, the total content of aluminum, silicon, chromium and titanium is 0.10 wt.% Or less, molybdenum: 0.05 wt.% Or less, tungsten: 0.02 wt.% Or less, niobium: 0.02 wt.% Or less, vanadium: 0.02 wt. % Or less, copper: 0.02 wt.% Or less, arsenic: 0.005 wt.% Or less, antimony: 0.01 wt.% Or less, boron: 0.0005 wt.% Or less, and residual iron and unavoidable impurities.

The manufacturing method of the Fe-Ni alloy cold-rolled sheet for the shadow mask excellent in the blackening process of the present invention comprises the following steps. A Fe-Ni-based molten alloy containing nickel in an amount within the range of 34 to 38 wt.% Was prepared, and oxygen was supplied to the Fe-Ni-based molten alloy in an electric furnace and / or a ladle. , Oxidize silicon, chromium, titanium, tungsten, niobium, vanadium and boron contained in the Fe-Ni-based molten alloy, absorb the generated oxide by CaO-based slag, and then remove the oxide. A shadow mask excellent in blackening treatment is obtained by casting the Fe-Ni molten alloy from which the material has been removed into an ingot, and then slab-rolling, hot-rolling, and cold-rolling the ingot. Manufactures Fe-Ni alloy cold rolled sheet.

The reason why the chemical composition of the Fe-Ni alloy cold-rolled sheet for a shadow mask excellent in blackening treatment of the present invention is limited to the above-mentioned range will be described below. (1) Nickel: Nickel is a component that greatly affects the coefficient of thermal expansion of the Fe-Ni alloy plate. The upper limit of the average coefficient of thermal expansion in the temperature range of 30 to 100 ° C required for Fe-Ni alloy sheet is about 2.0 × 10 ^-6 / ° C. The content of nickel that satisfies such an average coefficient of thermal expansion is 34 to 38 wt.%.
Range. Even if the nickel content is less than 34 wt.% Or more than 38 wt.%, The average coefficient of thermal expansion becomes higher than the above upper limit.

When a Fe-Ni alloy plate having a high average thermal expansion coefficient is used as a shadow mask material, it causes color misregistration. Therefore, the nickel content should be limited to the range of 34-38 wt.%. When nickel containing 0.01 to 6 wt.% Cobalt is used, the content of nickel satisfying the above average thermal expansion coefficient is in the range of 30 to 40 wt.%. Therefore, the nickel content is
If it is limited to the range of 38 wt.%, The average thermal expansion coefficient can be satisfied even in this case.

(2) Manganese: Manganese has a function of imparting desired strength to the Fe-Ni alloy plate. However, if the manganese content exceeds 0.35 wt.%, Fe-N
As a result of the generation of spinel oxide containing manganese on the i-based alloy plate, the blackness of the blackened film deteriorates. On the other hand, if the content of manganese is less than 0.05 wt.%, The alloy sheet cannot be provided with desired strength. Therefore, the manganese content is 0.05
It should be limited to the range of ~ 0.35 wt.%.

(3) Aluminum: Aluminum is Fe-N
It is an element added as a deoxidizer during the melting of i-based alloys. However, the aluminum content is 0.020 wt.%
If it exceeds, the blackness of the blackened film deteriorates as a result of the formation of aluminum oxide on the Fe-Ni alloy plate. On the other hand, when the aluminum content is less than 0.001 wt.%, There is no deoxidizing effect, and problems such as deterioration of surface properties occur. Therefore, the aluminum content should be limited to the range of 0.001 to 0.020 wt.%.

(4) Silicon: The content of silicon is 0.05w
When it exceeds t.%, the oxide of silicon is generated on the Fe-Ni alloy plate, and as a result, the blackness of the blackened film deteriorates. Therefore, the content of silicon should be limited to 0.05 wt.% Or less.

(5) Chromium: Chromium is one of the impurities that are inevitably mixed in when the Fe-Ni alloy is melted. When the chromium content exceeds 0.05 wt.%, Chromium oxide is formed on the Fe-Ni alloy plate, and as a result, the blackness of the blackened film deteriorates.
Therefore, the chromium content should be limited to 0.05 wt.% Or less.

(6) Titanium: Titanium is one of the impurities that are inevitably mixed during the melting of Fe-Ni alloys. When the titanium content exceeds 0.02 wt.%, Titanium oxide is formed on the Fe—Ni alloy plate, and as a result, the blackness of the blackened film deteriorates.
Therefore, the titanium content should be limited to 0.02 wt.% Or less.

(7) Total content of aluminum, silicon, chromium and titanium Even if the content of each of aluminum, silicon, chromium and titanium is within the above range, the total content of these is 0.10 wt. If it exceeds 0.1%, the blackness and heat emissivity of the blackened film deteriorate. Therefore, the total content of aluminum, silicon, chromium and titanium should be limited to 0.10 wt.% Or less.

(8) Molybdenum, tungsten, niobium,
Vanadium, copper, arsenic, antimony: In order to improve the thermal emissivity of the blackening film formed on the surface of the Fe-Ni alloy cold-rolled sheet, in addition to increasing the blackness of the blackening film, black It is necessary to promote the growth of the oxide film and form a blackened film having a predetermined thickness within a predetermined time. When the Fe-Ni alloy is melted,
Molybdenum, tungsten, niobium, vanadium, copper,
Arsenic, antimony, etc. are inevitably mixed in, but if the content of these elements exceeds the prescribed values, the growth rate of the blackened film decreases, and a blackened film of a given thickness should be formed within a given time. Can not be.

From the above viewpoint, the molybdenum content is set to 0.05 wt. % Or less, the content of tungsten is 0.
02 wt. % Or less, and the niobium content of 0.02 wt. %
Below, the content of vanadium was 0.02 wt. % Or less, the content of copper is 0.02 wt. % Or less, and the arsenic content of 0.
005 wt. % Or less, and the content of antimony
0.01 wt. Each should be limited to less than or equal to% .

When the contents of molybdenum, tungsten, niobium, vanadium, copper, arsenic and antimony exceed the above values, the reason why the growth rate of the blackening film is inhibited is not clear, but it is as follows. Presumed. That is, when the content of each element exceeds the above range,
Each of the above elements becomes concentrated at the interface between the Fe-Ni alloy cold-rolled sheet and the blackened film. As a result, it is difficult to form a black oxide film, that is, a blackened film, and the growth rate thereof is hindered.

(9) Boron: Boron is one of the impurities that are inevitably mixed in when the Fe-Ni alloy is melted. When the boron content exceeds 0.0005 wt.%, The adhesion of the blackened film deteriorates. Therefore, the content of boron should be limited to 0.0005 wt.% Or less.

(10) Hydrogen: CaO-based slag is generally used in the refining process when smelting an Invar alloy containing Fe-34 to 38 wt.% Ni. CaO 2 slag is a source of hydrogen in the alloy because it easily absorbs water. Therefore, hydrogen is inevitably mixed in the Fe-Ni alloy during its melting. As a result, when the blackening film is formed on the surface of the Fe-Ni alloy cold-rolled sheet, hydrogen gas is released from the alloy plate and the blackening film becomes porous, so that the rigidity of the blackening film is increased. Becomes smaller and the adhesiveness deteriorates. Such a problem becomes remarkable when the hydrogen content exceeds 1.0 ppm. Therefore, it is preferable to limit the hydrogen content to 1.0 ppm or less.

(11) Rare earth element: The rare earth element is one of the impurities that are inevitably mixed in when the present alloy is melted. The content of rare earth elements is 0.0002 in total of 1 or 2 or more
When it exceeds wt.%, the blackness of the blackened film deteriorates. Therefore,
The total content of one or more rare earth elements is 0.0002
It is preferable to limit it to wt.% or less.

Next, Fe-Ni for shadow mask of the present invention
A method for manufacturing a cold-rolled alloy sheet will be described. Fe in an electric furnace containing nickel in an amount in the range of 34 to 38 wt.%
-Prepare a Ni-based molten alloy. And in the electric furnace and /
Alternatively, oxygen is supplied into the molten Fe-Ni alloy in the ladle by blowing oxygen or adding an oxide such as mill scale into the slag. As a result, Fe-Ni
Impurities such as silicon, chromium, titanium, tungsten, niobium, vanadium, and boron contained in the molten alloys are oxidized, and the produced oxides are absorbed and removed by the CaO 2 slag.

By removing the above-mentioned oxide, the content of silicon in the Fe-Ni based molten alloy is 0.05 wt.% Or less, the content of chromium is 0.05 wt.% Or less, and the content of titanium is 0.02 wt. %
Below (however, the total content of aluminum, silicon, chromium and titanium is 0.10 wt.% Or less), the content of tungsten is 0.02 wt.% Or less, the content of niobium is 0.02 wt.% Or less, and the content of vanadium is Make the content 0.02 wt.% Or less.

In the Fe-Ni molten alloy, the manganese content is 0.35 wt.% Or less, and the aluminum content is 0.02%.
wt.% or less, molybdenum content is 0.05 wt.% or less, copper content is 0.02 wt.% or less, and arsenic content is 0.005 wt.%.
Below, and the raw materials are selected and adjusted so that the content of antimony is 0.01 wt.% Or less.

A Fe-Ni based molten alloy having the above-described composition is cast into an ingot, and then the ingot is slab-rolled, hot-rolled and cold-rolled. Thus, the Fe—Ni alloy cold-rolled sheet for the shadow mask, which is excellent in the blackening property, is manufactured.

[0029]

EXAMPLES Next, an Fe-Ni alloy cold-rolled sheet for shadow masks having excellent blackening processability and a method for producing the same according to the present invention will be described in comparison with Comparative Examples outside the scope of the present invention. Will be described in more detail. Fe-Ni alloy cold-rolled sheets were prepared using the raw materials shown in Table 1 by the following manufacturing process.

1. Dissolve steel scrap and nickel ingots as refining raw materials using an electric furnace, including the following: Slag-making acid 2. Refining using a VAD (vacuum-electric arc-degassing) facility including: 3. Use of VOD ( abbreviation of vacuum-oxygen-decarburization) equipment including refining, acid transfer, slag transfer, acid transfer decarburization, vacuum decarburization, deoxidation, slag deoxidation Lumps 5. Bulk rolling 6. Hot rolling 7. Cold rolling

[0031]

[Table 1]

Fe-Ni according to the invention in an electric furnace
An example of a process for refining a molten alloy of the Fe-Ni type is shown in the process flow chart of FIG. Each is shown. That is, in a 50t electric furnace equipped with a bottom plug for blowing a gas for stirring, slag, steel scrap and nickel metal were melted to prepare a Fe-Ni based molten alloy. The compositional composition of the obtained molten alloy is as shown in Table 2, and the compositional composition of the slag produced at the time of melting is as shown in Table 3.

[0033]

[Table 2]

[0034]

[Table 3]

Then, acid transfer was carried out in an amount of 10 to ³⁰ Nm ³ / t. The component composition of the Fe-Ni-based molten alloy after the acid transfer is shown in Table 4, and the component composition of the slag produced at that time is shown in Table 5.

[0036]

[0037]

Next, this was transferred into a 50-ton ladle, and this ladle was placed in a VAD (vacuum-electric arc-degassing) facility, where slag and heating were carried out. Then, add the ladle to V
It was placed in an OD (vacuum-oxygen-decarburization) facility, where acid feeding was carried out under the following conditions.

Degree of vacuum: 600 Torr or less, flow rate of top-blown oxygen gas: 12 Nm ³ / Hr · t, oxygen transfer rate: 2-5 Nm ³ / t, distance between lance and surface of molten alloy: 900 mm.

Table 6 shows the composition of the Fe-Ni molten alloy after the acid transfer, and Table 7 shows the composition of the slag produced at that time.

[0041]

[Table 6]

[0042]

[Table 7]

The Fe-Ni-based molten alloy thus obtained was subjected to slag removal, recasting and heating in a ladle.
Acid-delivered decarburization, vacuum decarburization, and deoxidation / slag deoxidation treatment were performed, and the molten alloy thus treated was cast into an ingot. Then, the ingot thus prepared,
Slab rolling, then slab surface care, hot rolling,
By a series of steps consisting of descaling, cold rolling, annealing, cold rolling and strain relief heat treatment, a specimen of the Fe—Ni alloy cold-rolled sheet of the present invention having a thickness of 0.15 mm (hereinafter referred to as the present invention (Specimen) No. 1 was prepared. Also,
The test piece of the present invention No. The material of No. 2 is also the invention described above.
Specimen No. Prepared by a method similar to 1.

For comparison, by the same process as in the above-mentioned invention except that oxygen is not supplied to the Fe-Ni based molten alloy by feeding oxygen or adding an oxide into the slag, Fe outside the scope of the invention with a thickness of 0.15 mm
Samples of cold-rolled Ni-based alloy (hereinafter referred to as comparative sample) Nos. 1 and 2 were prepared.

Table 8 shows the component composition of the slag when the Fe-Ni based molten alloy was prepared in the electric furnace during the production of the comparative specimen.

[0046]

[Table 8]

The above-described test sample of the present invention and the test sample for comparison were perforated by etching. The test piece having the etching perforations was annealed at a temperature of 810 ° C., and then subjected to a blackened film forming treatment at a temperature of 550 ° C. for 8 minutes.

With respect to the test piece on which the blackened film was thus formed, the adhesion, blackness, thermal emissivity, and unevenness of the blackened film were examined as follows.

(1) Adhesion of the blackened film: A tape was attached to the surface of the test piece, and 18 was applied to the test piece to which the tape was attached.
Tight bending was applied at an angle of 0 degree, and then the tape was peeled off. Then, the state of adhesion of the peeled blackened film on the tape was evaluated. The evaluation criteria are as follows. ⊚: The blackening film does not peel at all, and the adhesion is very good. ○: The blackening film hardly peels and the adhesion is good. Δ: The blackening film peels to some extent and the adhesion is slightly poor. X: Exfoliation of the blackening film is large and adhesion is poor.

(2) Blackness of the blackened film: The blackness of the blackened film of the test piece was visually evaluated. The evaluation criteria are as follows. ◎: Very good ○: Good △: Slightly bad ×: Bad

(3) Thermal emissivity: The thermal emissivity of the test piece when the thermal emissivity of the reference black body which completely absorbs heat was 1.0 was examined and evaluated.

(4) Occurrence of unevenness in blackening film The occurrence of unevenness in the blackening film of the test piece was visually evaluated. The evaluation criteria are as follows. ◎: No unevenness ○: Almost no unevenness △: Some unevenness ×: There is unevenness

Table 9 shows the results of investigations on the chemical composition of the samples of the present invention and the samples for comparison, and the adhesion, blackness, heat emissivity and unevenness of the blackened film.

Since the comparative specimens Nos. 1 and 2 were not supplied with oxygen during refining, as is apparent from Table 9, oxidation of silicon, chromium, titanium, tungsten, niobium, vanadium, boron, etc. Was not removed, and therefore these elements were hardly reduced, and the FeO activity of the slag was low as shown in Table 8. Therefore, the adhesion, blackness, and thermal emissivity of the blackened film were poor, and the blackened film was uneven.

On the other hand, the specimens No. 1 and 2 of the present invention
Had excellent adhesion, blackness and thermal emissivity of the blackened film, and unevenness did not occur in the blackened film. In particular, in the sample No. 1 of the present invention, since the amounts of silicon, chromium and titanium were reduced to more preferable levels, the adhesion, blackness and heat emissivity of the blackening film were further excellent.

[0056]

[Table 9]

[0057]

As described above, according to the present invention,
Manufacture Fe-Ni alloy cold-rolled sheet for shadow mask material, which has uniform blackness without unevenness, has blackening film with excellent heat radiation performance and adhesion, and has excellent blackening processability. It is possible to bring about an industrially useful effect.

[Brief description of drawings]

FIG. 1 is a flow system diagram showing an example of a process for refining a molten Fe—Ni alloy according to the present invention in an electric furnace.

FIG. 2 is a flow system diagram showing an example of a process for refining a Fe—Ni based molten alloy according to the present invention in a ladle.

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical indication location H01J 29/07 H01J 29/07 Z (72) Inventor Tadashi Inoue 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Japan Steel Pipe Co., Ltd. (72) Inventor Hidetoshi Matsuno 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Japan Steel Pipe Co., Ltd. (56) Reference JP-A-4-103743 (JP, A) JP-A-58-133324 ( JP, A)

Claims (5)

(57) [Claims] 1. Nickel: 34 to 38 wt. %, Manganese: 0.05 to 0.35 wt. %, Aluminum: 0.001 to 0.020 wt. %, Silicon: 0.05 wt. % Or less, chromium: 0.05 wt. % Or less, titanium: 0.02 wt. %, Provided that the total content of aluminum, silicon, chromium and titanium is 0.10 wt. % Or less, molybdenum: 0.05 wt. % Or less, tungsten: 0.02 wt. % Or less, niobium: 0.02 wt. % Or less, vanadium: 0.02 wt. % Or less, copper: 0.02 wt. % Or less, arsenic: 0.005 wt. % Or less, antimony: 0.01 wt. % Or less, boron: 0.0005 wt. % Or less, and the remainder, iron and unavoidable impurities, characterized in that it consists, Fe-Ni-based alloy cold-rolled sheet for excellent shadow mask in blackening resistance. 2. Further, the hydrogen content is 1.0 ppm or less,
The Fe-Ni alloy cold-rolled sheet according to claim 1, wherein the rare earth element content is 0.0002 wt.% Or less. 3. A Fe—Ni based molten alloy containing nickel in an amount within the range of 34 to 38 wt.
Or, in a ladle, oxygen is supplied to the Fe-Ni molten alloy to oxidize silicon, chromium, titanium, tungsten, niobium, vanadium and boron contained in the Fe-Ni molten alloy. , The generated oxide is Ca
It is absorbed into O 2 slag and removed, then the Fe-Ni molten alloy from which the oxide is removed is cast into an ingot, and then the ingot is slab-rolled, hot-rolled, and cold-rolled. Fe-Ni alloy cold-rolled sheet for shadow masks, which has excellent blackening processability, is manufactured by rolling, and Fe-Ni alloy cold-rolled sheet for shadow masks, which has excellent blackening processability, is manufactured. Manufacturing method. 4. The supply of oxygen to the Fe-Ni-based molten alloy in the electric furnace and / or in the ladle is controlled by the Fe
The method according to claim 3, which is carried out by blowing oxygen into the Ni-based molten alloy. 5. The method according to claim 3, wherein oxygen is supplied into the Fe—Ni molten alloy in the electric furnace and / or the ladle by adding an oxide such as mill scale into the slag. Method.