WO2003035920A1

WO2003035920A1 - Fe-Ni BASE ALLOY FOR SHADOW MASK RAW MATERIAL EXCELLENT IN CORROSION RESISTANCE AND SHADOW MASK MATERIAL

Info

Publication number: WO2003035920A1
Application number: PCT/JP2002/010718
Authority: WO
Inventors: Toru Nishi; Tsutomu Omori; Yutaka Kobayashi
Original assignee: Nippon Yakin Kogyo Co., Ltd.
Priority date: 2001-10-22
Filing date: 2002-10-16
Publication date: 2003-05-01
Also published as: JP2003129185A; CN100343405C; KR20040045877A; CN1571857A; US20040238076A1; EP1445341A1; JP3854121B2; EP1445341A4; KR100595393B1

Abstract

A Fe-Ni base alloy for a shadow mask raw material excellent in the resistance to corrosion having a chemical composition, in wt %: C ≤ 0.01 %, Si: 0.01 to 0.1 %, Mn: 0.01 to 0.1 %, Ni: 35 to 37 %, Cr ≤ 0.1 %, Nb: 0.01 to 1.0 %, S ≤ 0.0020 %, Al ≤ 0.005 % and balance: Fe and inevitable impurities; and a shadow mask material which comprises the Fe-Ni base alloy, wherein the alloy exhibits a 0.2 % yield strength of 300 N/mm2 or more, a thermal expansion coefficient in the range of 30 to 100˚C of 1.0 X 10-6/˚C or less. The Fe-Ni base alloy for a shadow mask raw material and the shadow mask material are free from the formation of rust even when exposed to the atmosphere for a long time due to transportation or the like after a bright annealing step as an intermediate step of the production of the material.

Description

Description Fe-Ni alloys for shadow mask materials with excellent corrosion resistance and shadow mask materials

The present invention relates to an Fe—Ni-based alloy and a shadow mask material for a shadow mask material having excellent corrosion resistance used for a color television cathode ray tube and the like, and in particular, is exposed to the air after light-volatilizing annealing in the material manufacturing process. We propose a high-rigidity, low-thermal-expansion Fe-Ni-based alloy with low corrosion and excellent corrosion resistance, and a shadow mask material using this alloy. Background art

Conventionally, low carbon aluminum killed steel sheets have been used as shadow mask materials. This steel sheet is, for example, a process in which the steel sheet after the intermediate cold rolling is strained in a continuous annealing furnace or a batch annealing furnace and subjected to intermediate annealing, followed by finish cold rolling and temper rolling (including dull rolling). It has been manufactured through.

In general, the material for high-definition color television CRT display is, for example, in the case of a color television picture tube, the electron beam passing through the shadow mask is less than 1/3 of the total, and the remaining The electron beam strikes the shadow mask, which heats it up to as much as 80 ° C. As a result, the shadow mask material undergoes thermal expansion and distortion, leading to a reduction in color purity. For this reason, it is advantageous to use a material having a small coefficient of thermal expansion as the material of the shadow mask material. In this sense, in recent years, an Fe-36Ni-based invar alloy, which is less affected by thermal expansion, has been used in place of the above-mentioned aluminum-killed steel sheet.

Among these Fe—Ni-based alloy sheets, in recent years, as the screen becomes flatter and larger, a low-thermal-expansion Fe-36Ni-based alloy sheet with reduced alloying element Mn (Japanese Patent Laid-open No. -Patent No. 1868653) and alloy plates with high strength by adding Nb (Patent No. 3150831) are used.

However, low-thermal expansion Fe-36Ni-based alloys with low Mn and high-strength Fe-36Ni-based alloys with the addition of Nb are not exposed to a corrosive environment in a bran tube in a vacuum atmosphere. In the process of distribution and transportation after light-volume annealing, there were cases where mackerel was generated due to long-term exposure to the air and did not become a product, leaving a problem in terms of server protection.

An object of the present invention is to provide a high-rigidity, low-thermal-expansion shadow that generates little mackerel even when exposed to the air for a long period of time for distribution or transportation after light-volatilization annealing, which is an intermediate step in the production of a material. Providing Fe-Ni alloy for mask material and shadow mask material

In view of the above-mentioned objectives, the inventors have set forth the conditions for Fe-Ni-based alloys that are unlikely to produce blue even when exposed to the atmosphere after light-volatilization annealing, which is an intermediate step in the production of materials. As a result of intensive research, the following findings were obtained. It is said that the 鲭 that occurs in the material (Fe-Ni-based alloy) is more likely to occur after light-volatilization annealing, and that the low thermal expansion Fe-36Ni alloy with reduced Mn is more likely to occur than ordinary Fe-36Ni alloy. I understand. Further investigation of this finding shows that the S concentration in the alloy from the surface to the depth of 150A (surface layer) of the low-Mn Fe-Ni-based alloy sheet is higher than that of the metal part (inner part). It was found to be significantly higher. As is generally known, when S is concentrated in the surface layer, S promotes dissolution of metal ions and induces mackerel. These phenomena can be solved by mechanically and chemically removing the surface layer of the alloy sheet, but it is difficult to perform this treatment on a commercial scale.

Therefore, the inventors have decided to suppress the concentration of S in the surface layer of the alloy sheet. According to the inventors' research, the concentration of S in the surface layer of the Fe-36Ni alloy It is absent in high-Fe-Ni alloys with high content, and is remarkable in low-thermal expansion Fe-36Ni alloys with low Mn content. Mn-based inclusions in Fe-Ni alloys with high Mn content It was found that S was incorporated in the low thermal expansion Fe-36ΝΪ alloy with a low Mn content, but the S enrichment decreased in inverse proportion to the Mn content. In other words, it was found that in the low thermal expansion Fe-36Ni alloy with a low Mn content, there was a lot of S that was not taken into the Mn-based inclusions, and this S diffused near the surface layer during bright annealing and became concentrated. .

On the other hand, the present inventors have obtained the knowledge that it is necessary to control the ratio of Mn to S of the Mn-based inclusion forming element in order to prevent the occurrence of 鑌, and to further study. Recommended. As a result, we found that when the relationship between Mn and S satisfies MnZS ^ SS, 鲭 hardly occurred. In addition, it was also found that mackerel formation was particularly difficult when the S concentration in the region (surface layer) up to 150 A from the surface of the alloy was about 20 times or less that of the bulk part (inside).

In addition, it was found that the corrosion resistance of the Fe—Ni alloy also greatly depends on the crystal grain size. In other words, the corrosion resistance after light-volatilization annealing greatly depends on the crystal grain size of the material. In particular, as the crystal grain size becomes smaller (the grain size number (ASTM) becomes larger), the corrosion resistance of the material improves. I also understood. This is considered to be because the area of the crystal grain boundary increases as the crystal grain size decreases, and the diffusion distance of S increases. Furthermore, it was found that controlling non-metallic inclusions in addition to the above countermeasures was also effective in suppressing the occurrence of mackerel. This is because the formation of acid-soluble MgO simple inclusions and CaO simple inclusions degrades the corrosion resistance when dew condensation occurs in the atmosphere, and the Nb-containing Fe-36Ni alloy suppresses the formation of alumina-based inclusions. generate for MnO -FeO- Si0 ₂ in _{_{_{- Nb 2 0 5 -MgO- A1 2}}} 0 3 - in CaO-based composite Sani匕物, when containing both the MgO simple substance inclusions or CaO alone inclusions, also It was found that the corrosion resistance deteriorated.

On the other hand, with these inclusions containing no MgO or CaO inclusions, there is no problem with the corrosion resistance. Therefore, in order to improve the corrosion resistance, MnO—FeO— _{_{_{Si0 2 -Nb 2 0 5 - MgO-}}} A1 2 0 3 - Besides the CaO-based composite Sani匕物, silica (Si0 _2), spinel _{_{(MgO · Α1 2 0 3)}} , and niobium oxide (Nb ₂ It was found that it was effective to use nonmetallic inclusions composed of one or more selected from the groups described in ( ₅ ).

The present invention has been completed based on these findings, and the gist configuration thereof is as described below.

That is, in the present invention, C≤0.01 wt%, Si: 0.01-0.1 wt ° / o, Mn: 0.01-0.1 wt%, Ni: 35-37 wt%, Cr≤0.1 wt%, Nb: 0.01- : 1.0 wt%, S≤0.0020 wt%, Al≤0.005 wt%, the balance is Fe and Ni-based alloy for mask material with excellent corrosion resistance consisting of Fe and unavoidable impurities.

In addition, the alloy of the present invention further comprises, in addition to the above component composition, one or more selected from Ti, V, Zr, Ta, Hf and REM in a total amount of 0.005 to 1.0. %.

The alloy according to the present invention is preferably an alloy in which the relationship between Mn and S is Mn / S≥25.

In the present invention, it is preferable that the maximum value of the S concentration in the region from the surface of the alloy to 150 A is not more than 20 times the bulk.

Still further, the alloy of the present invention preferably has a crystal grain size as large as No. 9 or more of the ASTM particle size number.

Furthermore, the alloy of the present _{_{invention, MnO- FeO- Si0 2 - Nb20 5}} - MgO- A1 2 0 3 - other CaO-based composite oxide, further silica (Si0 ₂₎ spinel (MgO · Α1 ₂ 0 ₃₎ Contact preferably contains a good beauty niobium oxide (Nb ₂ 0 ₅₎ any one or non-metallic inclusions consisting of those containing two or more of.

The present invention also provides the above Fe—Ni-based alloy, wherein the alloy has a 0.2% proof stress of 300 N / mm ² or more and a thermal expansion coefficient of 30 to: L00 ° C. of 1.0 × 10 ⁶ / ° C. or less. We propose a shadow mask material with high corrosion resistance, high rigidity and low thermal expansion. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the reasons for defining the composition of the Fe—Ni-based alloy according to the present invention as described above will be described.

C≤0.01 wt%

C is an element that contributes to the solid solution and the strengthening of the material by the work hardening action. If its content exceeds 0.01 wt%, a large amount of carbides will precipitate, deteriorating the etching properties, press formability, blackening properties and low thermal expansion properties. Therefore, the content of C is limited to 0.01 wt% or less. Preferably it is 0.005 ^% or less.

Si: 0.01—0.1 wt%

Si needs to be added as a deoxidizer in an amount of 0.01% or more as a deoxidizing agent when the alloy is refined. However, adding more than 0.1% by weight increases the thermal expansion.] Determined. Preferably it is 0.02-0.05 wt%.

Mn: 0.01-0.1 wt%

Mn is useful as a solid solution strengthening element, and it is necessary to add 0.01% or more as a deoxidizing material when refining the alloy. However, if its content exceeds 0.1 \ ^%, the thermal expansion will increase, so it was set to the range of 0.01-0.1 wt%. Preferably, it is 0.01 to 0.05 wt%.

In addition, the addition of Mn generates Mn-based inclusions, which fix the S that diffuses during photovoltaic annealing, so that a certain amount of Mn-based inclusions is required. Therefore, it is necessary to control this Mn so as to satisfy Mn / S25 in terms of corrosion resistance in relation to S.

Ni: 35-37 wt%

Ni is an element that has a significant effect on the thermal expansion characteristics of the Fe—Ni alloy. When this content is 36 wt%, thermal expansion is minimized, so Ni should be limited to 35-37 wt%.

Cr≤0.1 wt%

Cr is an element that significantly improves corrosion resistance, but if it exceeds 0.1 wt%, the thermal expansion coefficient And the blackening property is also poor, so the content is limited to 0.1 wt% or less.

Nb: 0.01 ~: LO wt%

When Nb is added to an alloy, the proof stress increases by 0.2%. In addition, it has the effect of remarkably reducing the crystal grain size, increasing the area of the crystal grain boundaries, and increasing the diffusion distance of S during light-volatilization annealing, thereby suppressing S concentration on the surface. In addition, it improves toughness, etching property, and pressurizing property, and also improves blackening property.

Therefore, Nb needs to be added in an amount of at least 0.01 wt% or more in order to obtain the above-mentioned effects, particularly to provide corrosion resistance and 0.2% proof stress. Preferably, 0.10 wt% or more is added. However, if added in excess of 1.0 wt%, the toughness, press formability, and low thermal expansion properties are rather reduced, so the content is limited to 0.01 to 1.0 wt%.

S≤ 0.0020 wt%

s is an element that characterizes the alloy according to the present invention, and has a significant effect on corrosion resistance. This S content is 0.0020 wt. /. If it exceeds, S diffuses into the vicinity of the material surface after light-volatilization annealing, and the S concentration at a depth of up to 150A from the material surface (surface layer) increases significantly with respect to the bulk, lowering the corrosion resistance. Therefore, the content of S is set to 0.0020 wt% or less, preferably 0.0010 wt% or less.

However, S needs to satisfy Mn / S≥25 in relation to Mn.

A1≤ 0.005 wt%

Since A1 is a relatively active element, if it is contained in a large amount, it causes preferential oxidation on the surface of the cooked rice, and inhibits black-and-white properties. Further, it increases the amount of A1 type oxidized product and inhibits the etching property. In particular, if the content exceeds 0.005 wt%, the low thermal expansion characteristics are reduced, so the content was limited to 0.005 wt%.

Ti, V, Zr, Ta, Hf and R E M

i, V, Zr, Ta, Hf and REM are elements that combine with C and N to form carbides and nitrides and contribute to grain refinement. It forms and contributes to corrosion resistance. Choose from Ti, V, Zr, Ta, Hf and REM (rare earth element) If at least one or more of them is used alone or in a total of less than 0.005 wt%, the above effects will be insufficient. On the other hand, if the content is more than 1.0 wt%, the solid solution amount of these elements becomes so large that the low thermal expansion characteristic is reduced.

Mn / S≥25

In the Fe—Ni alloy according to the present invention, Mn and S are represented by the following formula;

Mn / S≥25

It is necessary to make adjustments so as to fall within a range that satisfies the relationship of In other words, it is important to adjust the Mn content according to the S content, and control the S content, which adversely affects corrosion resistance, with Mn. In other words, when the ratio of Mn / S is less than 25, the amount of S incorporated into the Mn-based inclusions is small, and S diffuses and condenses to near the surface layer during bright annealing, so that a mackerel is easily generated. A preferred upper limit is about 70.

Next, in the Fe—Ni alloy according to the present invention, the S concentration in the region from the plate surface to 150 A is set to be about 20 times or less that of the bulk. This is because if the concentration of S in the surface layer exceeds 20 times the S concentration in the bulk (base), the dissolution of metal ions is promoted and the mackerel is induced. This S concentration is more preferably 18 times or less. In the present invention, in addition to the above-mentioned component design, it is effective to set the crystal grain size to a size of No. 9 or more in terms of an ASTM particle size number. According to the study of the present inventors, the corrosion resistance of a Fe—Ni alloy after light volatilization annealing largely depends on the crystal grain size of the material, and especially as the crystal grain size becomes smaller (the grain size number becomes larger), It was found that the corrosion resistance of the material was improved. In addition, since the 0.2% resistance greatly depends on the crystal grain size, it is desirable that the crystal grain size be AST M No. 9 or more in order to obtain excellent corrosion resistance and rigidity.

Non-Φ

In addition to the above component design and crystal grain size adjustment, the present invention further controls nonmetallic inclusions. In other words, non-metallic inclusions contained in the alloy of the present invention, MnO- FeO- Si 0 ₂ - Nb2_rei _{_{_{5 - MgO- A1 2 0 3 -}}} CaO -based composite oxide in addition to further, Si0 _2, MgO · A1 ₂ 0 _3, it is necessary to Nb ₂ 0 Non-metallic inclusions consisting of those containing one kind or two or more kinds of the _five. According to the inventors' research, it has been found that the generation of acid-soluble inclusions of MgO and CaO alone deteriorates the corrosion resistance when dew is formed in the atmosphere. In yet Nb-containing Fe- 36 Ni alloy, MnO -FeO- Si0 ₂ generates upon suppressing generate alumina-based inclusions - in CaO-based composite _{_{oxide, - Nb 2 0 5 - MgO-}} A1 2 0 3 It was also found that corrosion resistance deteriorated when both MgO and CaO inclusions were included. On the other hand, inclusions containing no MgO single inclusions or CaO single inclusions did not cause a problem in corrosion resistance. Example

Hereinafter, the working effects of the alloy according to the present invention will be specifically described with reference to examples, but the present invention is not limited to the examples described below.

The test material was manufactured by adjusting the components of the alloy so as to have the component composition shown in Table 1 below, and the test material was melted in an air induction furnace to produce an ingot. The ingot is hot forged at a temperature of 1000 to 1150 ° C, hot rolled at a rolling ratio of 80% or more, and 900 ° C-60 seconds, 30% H ₂ + N ₂ , dew point-40 ° The solid solution heat treatment was performed in the C atmosphere. Then, it was gradually cooled to obtain a 0.12 mm thick Fe-Ni alloy plate.

The coefficient of thermal expansion in the table is from room temperature to 300. Measured in the range up to C, the average coefficient of thermal expansion at 30 to 100 ° C was determined, and the 0.2% proof stress was measured by a tensile test. The maximum value of the amount of S enrichment in the region at 150 A from the plate surface was determined by using an Auger electron spectrometer at 50 A intervals from the surface, performing elemental analysis each time, and determining the atomic concentration of S. It was calculated and expressed as a ratio to parc (bulk is a value obtained by chemically analyzing the entire material in this case). The corrosion resistance was evaluated by the outdoor air exposure test, and the corrosion status after exposure was evaluated based on the area ratio of occurrence. In addition, those with an emission area ratio of 0.5% or more generate 鲭 when exposed to the atmosphere for a long time after bright annealing, which is an intermediate process of material production. It was unsuitable as a material. Table 2 shows the results.

As is evident from Table 2, it can be said that the alloy conforming to the present invention has sufficient properties in terms of corrosion resistance, rigidity and low thermal expansion properties. That is, the test material according to the present invention has a 0.2% proof stress of 300 NZmm2 or more, has high rigidity, and has a low thermal expansion coefficient of 1.0Χ10 · ⁶ / ° 〇 or less. In addition, the mackerel area ratio after the air exposure test is 0.5% or less, and it has excellent corrosion resistance. On the other hand, the comparative materials 19 and 20 are inferior in corrosion resistance due to the large amount of S in the bulk. In addition, the comparative materials 21 and 22 are inferior in corrosion resistance because the inclusion form includes MgO alone and CaO alone. Comparative material 23 is inferior in corrosion resistance and rigidity due to the large crystal grain size. Comparative Example 24 is inferior in corrosion resistance because the maximum value of the S concentration in the region at 150 A from the plate surface is 20 or more. Incidentally, the above-mentioned Fe—Ni-based alloy of the present invention produced as a shadow mask material could be produced without occurrence of Δ after light-volatilization annealing. In particular, the 0.2% proof stress before mask molded as quality material is not less 300 NZmm ² or more, the thermal expansion coefficient to produce a shadow mask material of high rigidity is and low thermal expansion below 1.0 X 10- ⁶ / ° C Was completed.

Alloy number 0.2% Power resistance coefficient of thermal expansion Grain size S content of lux Relative ratio from surface layer to 150A After air exposure test

(N / mm ² ) No. (A) s; gas large value (B) (Β / Α) Departure i blue surface 85 rate (! 0

1 315 0.81 1 1 0.0003 0.0050 16.8 0.26

2 316 0.84 10 0.0008 0.0013 16.1 0.24

Dep. 3 320 0.88 1 1 0.0010 0.0152 15.2 0.25

Akira 4 318 0.89 10 0.0012 0.0218 18.2 0.30

5 319 0.88 11 0.0012 0.0160 13.3 0.24

6 305 0.83 9 0.0015 0.0260 17.3 0.26

7 340 0.92 10 0.0010 0.0170 17.0 0.27

8 351 0.95 10 0.0013 0.0224 17.2 0.29

y 321 0.88 11 0.0012 0.0223 18.6 0.31

ι υ 318 0.85 10 0.0018 0.0311 17.3 0.32

1 1 316 0.87 11 0.0008 0.0146 18.3 0.31

322 0.85 11 0.001 1 0.0193 17.5 0.30

319 0.89 1 1 0.0015 0.0252 16.8 0.30

14 31 7 0.87 11 0.0010 0.0153 15.3 0.27

15 335 0.93 1 1 0.0008 0.0145 18.1 0.30

16 309 0.86 1 1 0.0012 0.0226 18.8 0.32

17 31 2 0.88 1 1 0.0012 0.0223 18.6 0.33

18 319 0.89 1 1 0.001 1 0.0187 17.0 0.30

19 319 0.85 10 0.0022 0.1 1 18 50.8 0.97

Ratio 20 315 0.88 1 1 0.0030 0.1458 48.6 0.92

Comparison 21 316 0.83 10 0.0025 0.0770 30.8 0.60

22 319 0.85 11 0.0035 0.0990 25.7 0.52

Fri 23 290 0.80 7 0.0015 0.0260 17.3 0.51

24 320 0.88 11 0.0020 0.0430 21.5 0.50

S】 2 Industrial applicability

As described above, according to the present invention, even when exposed to the atmosphere in the course of distribution and transportation after light-volatilization annealing, which is an intermediate step of material production, mackerel is less likely to occur.High corrosion resistance, high rigidity and low heat An Fe—Ni-based alloy for an expanded shadow mask can be provided. Therefore, it is possible to reliably provide a high-quality, high-yield shadow mask material for color CRTs and displays with beautiful images.

Claims

The scope of the claims

(1) C≤0.01wt%, Si: 0.01 ~ 0.1wt%, Mn: 0.01 ~ 0.1wt%, Ni: 35 ~ 37wt% s Cr≤0.1wt% Nb: 0.01 ~: 1.0wt%, S≤0.0020 wt ° / ₀ Al ≤ 0.005wt% Fe-Ni-based ^^ for shadow mask materials, with the balance being Fe and unavoidable impurities, and having excellent corrosion resistance.

(2) The alloy according to claim 1, wherein the relationship between Mn and S is Mn / S25.

(3) In addition to the above components, further contains one or more selected from Ίϊ, V, Zr, Ta, Hf and REM in a total amount of 0.005 to: 1.0%. The Fe—Ni-based opening 用 o for a shadow mask material according to claim 1 or 2, wherein

(4) In the alloy having the component composition according to any one of claims 1 to 3, the maximum value of the S concentration in the region from the surface to 150A is controlled to be 20 times or less that of the bulk. The Fe-Ni alloy for a shadow mask material according to any one of claims 1 to 3, characterized in that:

(5) The Fe—Ni-based ^^ for a shadow mask material according to any one of claims 1 to 4, wherein the crystal grain size is a size of ASTM No. 9 or more.

(6) MnO- FeO- Si_rei_2- _{_{_{Nb 2 0 5 - MgO- A1 2}}} 0 3 - other CaO-based composite oxide, further silica (Si0 ₂₎ spinel (MgO · Α1 ₂ 0 ₃₎ and niobium oxide (Nb ₂₀

_The shadow mask material having excellent corrosion resistance according to any one of claims 1 to 5, characterized by containing a non-metallic inclusion comprising one or more of any one of the above (5). For Fe-Ni alloy.

(7) The Fe—Ni alloy according to any one of claims 1 to 6, wherein the alloy has a 0.2% proof stress of 300 N / mm ² or more and 30 to: 100. First heat expansion coefficient of the C is 1.0 × 10 ⁶

A high-corrosion-resistant, high-rigidity, low-thermal-expansion shadow mask material having characteristics of / ° C or less.