WO2001077399A1

WO2001077399A1 - Raw material for shadow mask, method for production thereof, shadow mask and picture tube

Info

Publication number: WO2001077399A1
Application number: PCT/JP2001/002230
Authority: WO
Inventors: Toshiyuki Ueda; Shinichi Aoki; Taizo Sato
Original assignee: Toyo Kohan Co., Ltd.
Priority date: 2000-04-05
Filing date: 2001-03-21
Publication date: 2001-10-18
Also published as: AU2001242736A1; JP2001288540A

Abstract

A raw material for a shadow mask comprising a cold rolled steel sheet having a chemical composition: C: ≤ 0.0008 wt %, Si ≤ 0.03 wt %, Mn: 0.1 to 0.5 wt %, P: ≤ 0.02 wt %, S: ≤ 0.02 wt %, Al: 0.01 to 0.07 wt %, N: ≤ 0.0030 wt %, B: 0.5 ≤ B/N ≤ 2, balance: Fe and inevitable impurities; a method for producing the material; a shadow mask using the material; and a picture tube using the shadow mask. The material has magnetic properties which are excellent and also homogeneous in a coil.

Description

Description Material for shadow mask, manufacturing method thereof, shadow mask and picture tube

The present invention relates to a cold-rolled steel sheet as a shadow mask material used for a shadow mask used in a color picture tube, a method for manufacturing the same, a shadow mask using the cold-rolled steel sheet, and a picture tube incorporating the shadow mask. . Background art

Cold-rolled steel sheets, which are materials for shadow masks, are conventionally manufactured by the following manufacturing process.

I

Have been. That is, low-carbon steel manufactured by a steel maker is pickled and cold-rolled to a predetermined thickness, then degreased, and then subjected to decarburization annealing in a box-type annealing furnace in a wet water atmosphere. The thickness of the final product was reduced by secondary cold rolling as needed.

The cold-rolled steel sheet manufactured by this manufacturing method is photoetched by an etching maker, annealed by a press maker for softening, pressed into a predetermined shape, and then reddish To prevent this and reduce the emissivity, annealing is performed in an oxidizing atmosphere to form an oxide film called a blackened film on the surface. One of the important characteristics required here is soft magnetic characteristics.

The shadow mask inside the TV cathode ray tube, together with the inner shield, protects the straightness of the electron beam from the external magnetic field (hereinafter referred to as the environmental magnetic field) such as terrestrial magnetism. is there. Also, since the shadow mask material is magnetized in the same direction according to the environmental magnetic field when the direction of the TV is changed, it is desirable that the demagnetization be excellent. These characteristics can be obtained from a hysteresis curve measured by the quadrupole Epstein method. It is desirable that the former have a high value of the maximum magnetic permeability (hereinafter, β max) and the latter have a small value of the coercive force (hereafter, He). , Especially H c is also valued by users.

In general, it is desirable that the crystal grains of Z max and He are coarse, but there is a limit to the coarsening of crystal grains in conventional materials, and the maximum temperature depends on the annealing temperature of each press maker. Hc = 103 to 135 A / m. An object of the present invention is to provide a shadow mask material having excellent magnetic properties uniformly in a coil, a method for manufacturing the same, a shadow mask using the cold-rolled steel sheet, and a picture tube incorporating the shadow mask. Things. Disclosure of the invention

The shadow mask material of the present invention contains N: ≤0.0030% by weight, 8: 0.5 B / N≤2, and preferably 0.2, with the balance being Fe. And unavoidable impurities.

. Shadow mask material of the present invention, component, C:. ≤ 0 001 5 wt%, desired properly is ≤ 0. 0008 wt ^{_{0/0, S i: ≤}} 0. 03 weight ^_0/0, Mn: ⁰ :! ~ 0.5 weight. /. , P: ≤ 0.02% by weight, S: ≤ 0.02% by weight. /. A1: 0.01 to 0.07% by weight, N: ≤ 0.0030 weight ⁰ / ο, B: 0.5 ≤ B / N ≤ 2, preferably 0.8 ≤ B / N ≤ 1.2 And the balance is composed of Fe and inevitable impurities.

Method for producing a material for a shadow mask of the present invention, component, N:. ≤0 0030 by weight ^{_{0/0, B: 0. 5≤BZN≤}} 2, and preferably is free Yes in relation 0.2 The remainder of the slab consisting of Fe and unavoidable impurities is hot-rolled at an Ar temperature of ₃ points or higher, hot-rolled at a winding temperature of 540 to 680 ° C, pickled, and then cold-rolled. Then, in the continuous annealing process, the residual C content was 0.0015 weight. / ₀ or less, preferably 0.0008% by weight or less.

Method of manufacturing a material for a shadow mask of the present invention, component, C:. ≤0 0008 double bulk ^{_{0/0, S i: ≤}} 0. 03 weight ^{_{0/0, Mn: 0.:}} ! ~ 0. 5 weight ^{_{0/0, P: ≤ 0.}} 02 weight. /. , S: ≤ 0.02 weight. /. A1: 0.01-0.07 weight. /. , N: ≤ 0. 0030 wt ^{_{0/0, B: 0. 5≤B}} / N≤ 2, preferably 0. 8≤BZN≤ 1. are contained in the second relationship, the balance F e and unavoidable The steel slab made of impurities is hot-rolled at Ar ₃ points or higher, hot-rolled at a winding temperature of 540 to 680 ° C, pickled, cold-rolled, and then subjected to a continuous annealing process. It is characterized in that the residual C content is reduced to 0.0001% by weight or less, preferably 0.0008% by weight or less.

The shadow mask of the present invention is characterized by using the shadow mask material.

The picture tube according to the present invention is characterized in that the shadow mask is incorporated therein. BEST MODE FOR CARRYING OUT THE INVENTION

The following are preferred as components of the hot-rolled steel sheet.

N≤ 0. 0 0 3 0 wt ^{_{0/0, B: 0. 5≤}} B / N≤ 2, preferably is contained in relation to 0. 8≤BZN ≤ 1. 2, balance F e and unavoidable It is desirable that the steel slab be made of magnetic impurities.

N: ≤ 0.0030% by weight

N in steel is desirable because it forms a nitride with A 1, reduces solute N and reduces the aging effect. Further, in order to ensure press moldability as a shadow mask material, it is necessary to minimize the amount, so that the upper limit is desirably 0.0030% by weight. More preferably 0.0020 weight. / ₀ or less.

B: 0.52, preferably 0. δ ^ Β / Ν ^ Ι. 2

Since Β in the steel coarsens the crystal grains of the thin steel sheet, it has an excellent effect on the magnetic properties as a shadow mask material. In particular, the effect of addition is remarkable in an ultra-thin shadow mask having a plate thickness of about 0.08 mm to 0.25 mm, which has been used recently.

In addition, B in steel is an element effective for fixing solid solution N, so it is desirable to add B. On the other hand, an excessive amount of added B can reduce crystal grains and impair magnetic properties. Therefore, it is desirable to be within a certain range.

In the present invention, B is desirably contained in a range satisfying the above formula. That is, when the relationship between B and N is within this range, as shown in Tables 1 and 3, it is understood that excellent magnetic properties are exhibited. Furthermore, in the present invention, it has recently been used to regulate the following as billet components, which are the materials of the hot-rolled steel sheet: 0.08 mn! It is preferable as a material for so-called ultra-thin shadow masks with a thickness of about 0.25 mm.

That is, C: ≤0.0008% by weight, Si: ≤0.03 weight ⁰ / o, Mn: 0.1 to 0.5 weight. /. , P: ≤ 0.02 weight. /. , S: ≤ 0.02% by weight, A1: 0.01 to 0.07% by weight. The reasons for the regulation are described below.

C: ≤ 0.003% by weight

The amount of C in the hot-rolled steel sheet greatly affects the continuous annealing process for decarburization. If it exceeds 0.0003% by weight, decarburization in the continuous annealing process is not sufficient, and it is contained in the shadow mask material. The prescribed 0.0008 weight. In order to reduce the temperature to / ₀ or less, it is necessary to increase the annealing temperature and the annealing time, which increases the production cost and decreases the productivity. Therefore, it is desirable to set the upper limit to 0.0030% by weight. The content is preferably 0.025% by weight, more preferably 0.0020% by weight or less.

S i: ≤ 0.03% by weight

S 1 in the shadow mask material is an element that inhibits blackening in the blackening process in the manufacture of a picture tube, and a smaller amount is preferable, but an element inevitably contained in A1 killed steel. The upper limit is preferably set to 0.03% by weight. Desirably, it is 0.025% by weight, more preferably 0.02% by weight or less.

Mn: 0:! To 0.5% by weight

Since Mn in the hot-rolled steel sheet is a component necessary to prevent red hot embrittlement during hot rolling due to the impurity S, the ultra-thin shadow mask material of the present invention is prone to cracking during cold rolling, so it is actively used. It is preferable to add a predetermined amount. This effect is 0.1-fold % Or more is preferred, but preferably 0.25% by weight. / ₀ or more.

On the other hand, if the content exceeds 0.6%, the formability is deteriorated. Therefore, the content is preferably 0.5% by weight, preferably 0.40% by weight, more preferably 0.35% by weight or less, and is there.

P: ≤ 0. 02 weight ^_0/0

P in the shadow mask material has poor magnetic properties due to the refinement of crystal grains, and the smaller the P, the better. Particularly, the effect of the ultra-thin shadow mask material of the present invention is remarkable, and preferably 0.02% by weight or less.

S: ≤ 0.02 weight. /.

S in the hot-rolled steel sheet is an element that is inevitably contained, is an impurity component that causes red-hot embrittlement during hot rolling, and is desirably as small as possible. Since the ultrathin shadow mask material of the present invention is liable to crack during cold rolling, it is preferable to actively remove the material. This effect is preferably 0.02% by weight or less, but preferably 0.01% by weight or less.

A 1: 0.01 to 0.07 weight. / o

A1 in the hot-rolled steel sheet is added to the steel bath as a deoxidizing agent during steelmaking and is removed as slag. However, if the added amount is small, a stable deoxidizing effect cannot be obtained. Therefore, this effect is preferably added at 0.01% by weight or more, more preferably at 0.02% by weight or more.

On the other hand, the effect is small even if it exceeds 0.07% by weight. Also, in this report, the purpose is to increase the crystal grains, and it is not desirable to make the crystal grains fine by excessive addition of A1, and it is desirable that the content be 0.07% by weight or less, more preferably, 0% or less. . 04% by weight or less.

Remaining part: The remaining part does not regulate elements that are inevitably contained so as not to impair Fe and etching properties and press formability.

Next, a method of manufacturing the ultra-thin shadow mask material of the present invention will be described. Slab The heating temperature and the hot rolling conditions are not specified in the present invention. However, if the slab heating temperature is lower than 110 ° C., the hot rollability deteriorates and the viewpoint of securing the hot rolling temperature is reduced. Therefore, it is desirable that the temperature be higher than 110 ° C. On the other hand, if the slab heating temperature is too high, the crystal grain boundaries will be embrittled during the slab, and it is desirable that the temperature does not exceed 125 ° C. The hot-rolling finishing temperature is not particularly limited.However, if the Ar temperature is less than ₃ points, phase transformation occurs during rolling, so the rolling width is difficult to control, and the rolling width may be smaller than the specified width. It is desirable that the number of A r can be rolled is ₃ or more. The lower limit of the winding temperature is preferably set at 540 ° C in consideration of the quality stability in the coil width direction and the longitudinal direction during hot rolling. On the other hand, if the temperature exceeds 680 ° C, the descaling property deteriorates. Therefore, it is desirable to set the temperature in the range of 540 to 680 ° C.

(Pickling, primary cold rolling process)

Pickling and primary cold rolling may be performed under ordinary conditions. In order to efficiently perform decarburization annealing of the ultra-thin shadow mask material of the present invention, it is desirable that the sheet thickness after the first cold rolling be 0.6 mm or less.

(Continuous annealing process)

The continuous annealing step is an important step in the present invention. The sheet temperature is at least 75 ° C., the soaking time is at least 60 seconds, the annealing atmosphere is at a hydrogen concentration of 0 to 75%, and the remaining N ₂ force is It is desirable to perform continuous annealing at a dew point of −30 to 70 ° C.

(Annealing temperature)

The annealing temperature affects the decarburization efficiency and magnetic properties.If it is lower than 75 ° C, it takes a long time to decarburize, not only lowering the productivity, but also the recrystallized structure after annealing. There is unevenness, and uniform magnetic properties cannot be obtained. Therefore, it is preferable that the annealing temperature is set to be equal to or higher than 75 ° C. More preferably, the temperature is 800 ° C. or more.

(Annealing time)

The annealing time is preferably set to 60 seconds or more. ^In less than ⁶⁰ seconds, ultra-thin shadows Decarburization as a mask material is insufficient, and it is difficult to reduce the target C content to 0.0008% or less. The upper limit is not particularly limited, but is preferably 180 seconds or less from the viewpoint of productivity and prevention of coarse particles.

(Hydrogen concentration and dew point in continuous annealing atmosphere)

If the hydrogen concentration in the continuous annealing atmosphere is maintained at 70% or less, the C content of the ultra-thin shadow mask material can be reduced to 0.0008% or less. Even if the hydrogen concentration exceeds 70%, there is no difference in the decarburization time, and the cost is rather increased. Therefore, it is preferable to set the upper limit to 70%. If the dew point is in the range of 135 to 70 ° C, the C content of the ultra-thin shadow mask material can be reduced to 0.0008% or less.

(Secondary cold rolling after annealing)

The rolling ratio of the secondary cold rolling after annealing is preferably 41 to 90%, and more preferably 55 to 90%, in order to impart the necessary strength to the ultra-thin shadow mask material. If it is less than 55%, the required strength cannot be obtained, and if it is more than 91%, the number of times of rolling increases and the productivity decreases, so the upper limit is preferably made 90%. By the second cold rolling, a material having a final thickness of the ultra-thin shadow mask material of the present invention of 0.08 to 0.25 mm is obtained. Example

Hereinafter, the present invention will be described in more detail with reference to Examples. Hot rolling of billets 2.

A hot-rolled steel sheet of 3 mm was pickled and then cold-rolled into a cold-rolled sheet having a thickness of 0.55 mm. The carbon content of the cold-rolled sheet was 0.0022% by weight in Example 1, and 0.0002 in Example 2.

3 weight. /. In Example 3, it was 0.0028% by weight, in Comparative Example 1, it was 0.0019% by weight, and in Comparative Example 2, it was 0.045% by weight. Then, in the continuous annealing process, decarburization annealing was performed under the conditions shown in Table 2. Tables 1 and 2 show the amounts of steel components after decarburization, the annealing conditions, and the secondary cold rolling reduction. An ultra-thin shadow mask material with a thickness of 0.25 mm was produced by secondary cold rolling. Example of chemical composition and chemical composition (wt%) B / N is comparative example C Si Hn PS Al NB Example 1 0.0008 0.01 0.10 0.006 0.005 0.059 0.0030 0.0021 0.89 Example 2 0.0008 0.01 0.15 0.005 0.004 0.060 0.0029 0.0013 0.57 Example 3 0.0011 0.02 0.24 0.009 0.008 0.063 0.0021 0.0031 1.88 Comparative Example 1 0.0008 0.01 0.14 0.006 0.005 0.061 0.0028 0.0003 0.14 Comparative Example 2 0.0007 0.01 0.23 0.016 0.015 0.054 0.0023 0.0002 0.11

Table 2

Table 3

Example Mechanical properties Magnetic properties Magnetic properties or TSTEL Soaking: 600 Soaking: 650 "C Soaking: 725 Soaking: 800 Total Comparative Examples (UPa) () He μ max He μ max He / imaz He iniax evaluation

(A / m) (A / m) (A / m) (A / m)

Example 1 605 1.4 111 3200 112 3250 105 3650 96 4300 © Example 2 607 1.4 119 3150 117 3200 110 3590 99 4200 O Example 3 610 1.3 118 3190 117 3250 109 3620 98 4100 O Comparative example 1 607 1.4 131 3140 126 3190 115 3450 102 4000 Δ Comparative Example 2 610 1.3 139 2950 127 3200 123 3150 111 3250 X Next, Table 3 shows the evaluation results of the magnetic properties of the obtained shadow mask material. In Table 3, the mechanical properties were evaluated by cutting a steel sheet whose surface roughness was given by temper rolling after secondary cold rolling into JIS No. 5 test pieces. In Table 3, TS indicates tensile strength and T.EL indicates elongation. The magnetic properties of the steel sheet subjected to the above-mentioned secondary cold rolling and temper rolling are 5.5 volumes of N ₂ gas. / ₀ and H ₂ gas 9 4. 5 vol. Dew point in an atmosphere containing / ₀ and annealed at 10 ° C for 10 minutes in the range of 600 to 830 ° C, and μmax and He are determined by the quadrupole Epstein method. Was.

As described above, // max and He, which are important parameters of the magnetic properties, can substitute the magnetic properties after forming and blackening in the evaluation of an annealed sheet obtained by annealing a cold-rolled steel sheet before pressing.

Although the temperature of this pre-press annealing varies depending on the press manufacturer, it is in the range of 600 to 80 ° C, so annealing was performed in this temperature range.

In the comprehensive evaluation of magnetic properties in Table 3, © and △ are good for both umax and He, △ is slightly inferior to Hc after pre-press annealing at relatively low temperature, and X is relatively poor. Hc after annealing at low temperature before press is inferior. Industrial applicability

As shown in Table 3, the present invention provides a shadow mask having a large max, a small He, and good magnetic properties in the entire temperature range of pre-press annealing at a press manufacturer, as shown in Table 3. The material is obtained.

Also, as the pre-press annealing temperature increases, secondary recrystallization, that is, grain growth occurs, so that the crystal grains of the product increase and the magnetic properties improve. That is, β max is large and He is small. The magnetic properties of the present invention are better than those of Comparative Examples 1 and 2 in the entire range of 600 to 800 ° C. That is, the present invention is better than Comparative Example 1 due to the effect of B in the component, and better than Comparative Example 2 is due to the high temperature annealing after cold rolling in addition to the effect of B in the component.

Also, many users have a pre-press annealing temperature of around 700 ° C. In this case, even if the pre-press annealing temperature for these users was lowered by 100 ° C to 600 ° C, the magnetic properties pre-press-annealed at 725 ° C in Comparative Example 2, which is the conventional material, did not Is also good. Therefore, the pre-press annealing temperature of the press manufacturer can be reduced by 100 ° C, and the energy cost can be reduced.

Claims

The scope of the claims

1. A material for shadow masks containing 0.30% by weight of components and 8: 0.5≤ 、, Ν≤2, with the balance being Fe and unavoidable impurities.

2. Ingredients: C: ≤ 0.0015% by weight, S i: ≤ 0.03% by weight, Mn: 0.1 to 0.5% by weight. /. , P: ≤ 0.02% by weight, S: ≤ 0.02% by weight, A1: 0.

0 1 to 0.07% by weight, N: ≤ 0.030% by weight. /. , B: A material for shadow masks that is contained in a relationship of 0.5≤B / N≤2, with the balance being Fe and unavoidable impurities.

3. The component is C: ≤0.008 weight. The shadow mask material according to claim 2, wherein the ratio is / ₀ .

4. The material for a shadow mask according to any one of claims 1 to 3, wherein the component is contained in a relation of Β: 0.8 ≤ B / N ≤ 1.2.

5-Ingredients are contained in the following relationship: Ν: ≤ 0.0000% by weight, 8: 0.5 ≤ ΒΖΝ ≤ 2, the balance being Fe and unavoidable impurities. Finish rolling is set to ₃ points or more, hot rolling is performed at a coiling temperature of 540 to 680 ° C, pickling is performed, then cold rolling is performed, and the residual C amount is determined in a continuous annealing process. A method for producing a shadow mask material, wherein the content is 0.005% by weight or less.

6. The component is C: ≤ 0.003 weight. /. , S i: ≤ 0.03 weight ⁰ /. , Mn: 0 .:! -0.5% by weight, P: ≤0.02% by weight, S: ≤0.02% by weight. /. A1: 0-0.1 to 0.07 weight. /. , N: ≤ 0.03 0 weight. /. , B: are contained in relation to 0. 5≤B / N≤ 2, the steel strip and the balance being F e and unavoidable impurities, the finish hot rolling or more A r ₃ points, the coiling temperature A shadow characterized by hot rolling at 540 to 680 ° C, pickling, cold rolling, and then reducing the residual C content to 0.0015 wt% or less in a continuous annealing process. Manufacturing method of mask material.

7. Make sure that the above components are contained in the relationship of B: 0.8≤B / N≤1.2. 7. The method for producing a shadow mask material according to claim 5, wherein:

8. The method for producing a shadow mask material according to claim 5, wherein the residual C content is set to 0.0008% by weight or less.

9. A shadow mask using the material according to claims 1 to 4.

10. A picture tube incorporating the shadow mask according to claim 9.