JPH05209254A - Fe-ni alloy thin sheet for shadow mask excellent in press formability and its manufacture - Google Patents

Abstract

PURPOSE:To provide an Fe-Ni invar alloy thin sheet for a shadow mask excellent in press formability and having excellent shape freezability at the time of forming, good fitness with a die and the capacity of suppressing the generation of cracks even in the case of annealing treatment at a low temp. for short time. CONSTITUTION:The objective Fe-Ni invar alloy thin sheet for a shadow mask is constituted of 34 to 38% Ni, <=0.05% Si, <=0.0005% B, <=0.0020% O and <=0.0015% N, and the balance Fe with inevitable impurities, and in which 0.2% proof stress after annealing before press forming is regulated to <=28.5kgf/mm<2> and the degree of accumulation on the {211} crystalline plane to the alloy surface is regulated to <=16%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Fe-Ni alloy thin plate excellent in press formability, and relates to a preferable Fe-Ni alloy thin plate for a shadow mask used for a color cathode ray tube and a method for producing the same. ..

[0002]

2. Description of the Related Art In recent years, with the increasing quality of color televisions,
As a shadow mask alloy that can deal with the problem of color misregistration, a Fe-Ni alloy containing 34 to 38 wt% Ni (hereinafter referred to as "conventional Fe-Ni alloy") is used. This conventional Fe-Ni alloy has a remarkably small coefficient of thermal expansion as compared with the low carbon steel conventionally used as a shadow mask material. Therefore, if the shadow mask is made of the conventional Fe-Ni alloy, even if the shadow mask is heated by the electron beam, the problem of color shift due to thermal expansion of the shadow mask is unlikely to occur.

An alloy thin plate for a shadow mask is usually manufactured by the following steps. That is, an alloy ingot is prepared by a continuous casting method or an ingot making method, and then the alloy ingot thus prepared is subjected to slab rolling, hot rolling and cold rolling.
Annealing is performed to manufacture an alloy thin plate.

The alloy thin plate for a shadow mask manufactured as described above is usually processed into a shadow mask by the following steps. That is, through a photoetching on the alloy thin plate for the shadow mask, the electron beam passage hole (hereinafter,
Simply called "holes") (hereinafter, the thin alloy plate for shadow masks that has been punched by etching is called "flat mask"), then annealed the flat mask, and then annealed the flat mask. , Press-molded into a curved shape so as to match the shape of the cathode ray tube, then, this is assembled into a shadow mask, and the surface thereof is subjected to blackening treatment.

However, when such a conventional Fe-Ni alloy is used, the strength is higher than that of the shadow mask material of the conventional low carbon steel, and this alloy is cold-rolled, recrystallized, annealed or recrystallized. The material for shadow masks manufactured by slight finishing rolling after crystal annealing should be softened and annealed at a temperature of 800 ° C or higher before press molding to coarsen the crystal grains due to the problem of press formability after etching perforation. We are trying to soften. After the softening and annealing, spherical molding was performed by a warm pressing method.

However, even at 800 ° C., the temperature is high,
From the viewpoint of work efficiency and economical efficiency, it is desired to develop a manufacturing method capable of obtaining the same low strength as that of the material softened and annealed at a temperature of 800 ° C. or more by softening annealed at a lower temperature than the current one. Therefore, the following prior art is known. That is, in JP-A-3-267320, cold rolling followed by recrystallization annealing is followed by finish cold rolling in a rolling reduction range of 5 to 20% to obtain a temperature of less than 800 ° C. At 730 ° C. for 60 min at 200 ° C.
The 0.2% proof stress is set to 9.5 kgf / mm ² (10 kgf / mm ² or less) to reduce the strength to a level with good press formability.

[0007]

However, in the above-described prior art, under the annealing condition of 730 ° C. for 60 minutes, the strength of the press formability is lowered to a satisfactory level. It has not been possible to satisfy all of the above-mentioned warm press molding qualities. That is, in the shadow mask material according to the above-mentioned technique, galling occurs in the mold during molding, and cracks are likely to occur at the end portions of the shadow mask.

[0008] Despite these problems, CRT manufacturers have been pursuing work efficiency and economic efficiency.
Attempts have also been made to anneal before pressing at the above-mentioned temperatures for shorter times. Incidentally, the annealing time is specifically 40 min or less, and in some cases, it may be a short-time treatment such as 2 min. When such an annealing condition is applied to the above-mentioned prior art, the occurrence of galling on the mold during press molding becomes more significant, the shadow mask frequently cracks, and this is a serious problem in terms of quality.

The present invention was devised after repeated studies in view of the above-mentioned circumstances, and has excellent press formability, and the annealing before pressing is as low as 720 ° C to 790 ° C and as short as 40 minutes or less. The Fe-Ni-based Invar alloy thin plate for shadow masks and the manufacturing method thereof that can impart the required press-forming quality even in the treatment at the annealing time are as follows, and are as follows. The press-molding quality of means that the shape-freezing property at the time of molding is excellent, the mold fits well (there is no galling with the mold), and the material does not crack.

(1) wt%, Ni: 34 to 38%, Si:
0.05% or less, B: 0.0005% or less, O: 0.0020
% Or less, N: 0.0015% or less, the balance is unavoidable impurities and the composition of Fe, and 0.2% proof stress is 28.5 kgf / mm in the alloy sheet before annealing before press forming.
² or less, and the degree of integration of {211} crystal planes on the surface of the alloy plate (hereinafter simply referred to as {211} crystal plane integration degree) is 16
% Fe or less Fe-Ni alloy thin plate for a shadow mask having excellent press formability, which is characterized in that

(2) A hot-rolled steel strip of a low thermal expansion alloy having the component described in the above item (1) is hot-rolled sheet annealed, then cold-rolled and subsequently recrystallized annealed, and then finished. At the time of manufacturing in the process of performing cold rolling, the hot rolled sheet annealing is performed at 910
The reduction ratio (R)% in the finish cold rolling is the austenite grain size D (μm) after the recrystallization annealing described above.
The annealing before the press forming is performed within the range of the region I shown in FIG. 3 according to the temperature (T ° C.) of 720 to 790 ° C., the time (tmin) of 2 to 40 min and T ≧ −53.8 log t + 8.
The alloy sheet after annealing has a 0.2% proof stress of 28.5 kgf / mm ² or less and an integration degree of {211} crystal faces of 16% or less. Fe for shadow mask with excellent press formability
-The manufacturing method of a Ni alloy thin plate.

(3) A hot-rolled steel strip of a low thermal expansion alloy having the composition described in the above item (1) is annealed by hot-rolled sheet, followed by cold rolling and subsequent recrystallization annealing, and then finish cooling. When manufacturing in the step of performing hot rolling, the hot rolled sheet annealing is performed at 910 ° C. to 990 ° C., and the reduction ratio (R%) in finish cold rolling is the austenite grain size D ( μm) within the range II shown in FIG. 3, and the subsequent annealing before press forming is performed at a temperature (T ° C.) of 7
20 to 790 ° C., time (tmin) is 2 to 40 min, and T ≧
By applying under the condition that −53.8 log t + 806 is satisfied, the 0.2% proof stress of the annealed alloy plate is 28.0 kgf / mm.
^A method for producing an Fe-Ni alloy thin plate for a shadow mask excellent in press formability, which comprises adjusting the degree of integration of {211} crystal planes to ² or less and 16% or less.

(4) A hot-rolled steel strip of a low-thermal expansion alloy having the composition described in the above item (1) is annealed by hot-rolling, followed by cold rolling and subsequent recrystallization annealing, and then finish cooling. When manufacturing in the step of performing hot rolling, the hot rolled sheet annealing is performed at 910 ° C. to 990 ° C., and the reduction ratio (R%) in finish cold rolling is the austenite grain size D ( μm) within the range shown in region III in FIG. 3, and the subsequent annealing before press forming is performed at temperature (T ° C)
Is 720 to 790 ° C., time (tmin) is 2 to 40 min, and T ≧ −53.8 log t + 806 is satisfied, so that 0.2% proof stress of the annealed alloy sheet is 27.5 kgf.
/ Mm ² or less, and the degree of integration of {211} crystal faces is 16%
A method for producing an Fe-Ni alloy thin plate for a shadow mask, which is excellent in press formability, which is adjusted as follows.

[0014]

Describing the present invention as described above, the inventors of the present invention have conducted earnest studies to develop an Fe-Ni alloy thin plate for a shadow mask excellent in press molding quality from the above viewpoint. As a result, the following findings were obtained. That is, the present invention obtains a required press-forming quality by adjusting the chemical composition of the Fe-Ni alloy thin plate for a shadow mask, the 0.2% proof stress and the crystal orientation within a predetermined range. Is.

More specifically, the inclusion of B and O within a predetermined range enhances the crystal grain growth during annealing before pressing under the conditions characterized by the present invention, and lowers the yield strength by coarsening. Then, the inclusion of Si and N within the predetermined range improves the compatibility with the mold during press molding (suppresses the occurrence of galling on the mold), and further in the alloy thin plate after annealing before pressing { Two
11} By setting the degree of integration of crystal faces within a predetermined range, it is possible to suppress the occurrence of material cracking during press molding.

Further, the present inventors have obtained the following findings. That is, in the manufacturing process of the present alloy, hot-rolled steel strip is annealed at a predetermined temperature before cold-rolling the hot-rolled steel strip, and further, the reduction ratio in the finish cold-rolling is the same as that before the finish cold-rolling. By appropriately changing the grain size of austenite, the 0.2% proof stress and the degree of integration of {211} crystal faces of the alloy sheet after annealing before pressing can be adjusted within a predetermined range.

The present invention has been made on the basis of the above-mentioned findings. The chemical composition of the Fe-Ni alloy thin plate for shadow mask of the present invention, 0.2 after pre-press annealing is described below. The reasons for limiting the% yield strength and the degree of integration of crystal planes are as follows.

(1) Nickel: The upper limit of the average thermal expansion coefficient in the temperature range of 30 to 100 ° C. required for the Fe-Ni alloy thin plate for a shadow mask in order to prevent the occurrence of color shift is about It is 2.0 × 10 ⁻⁶ / ° C. The coefficient of thermal expansion depends on the nickel content of the alloy sheet. Then, the range of nickel content satisfying the above-described condition of the average thermal expansion coefficient is in the range of 34 to 38 wt%. Therefore,
The nickel content should be limited to the range 34-38 wt%.

In the present invention, the yield strength required for improving the shape fixability at the time of press forming and suppressing the occurrence of cracks in the alloy sheet is premised on warm pressing.
The upper limit was set at 28.5 kgf / mm ² at 0.2% proof stress at room temperature. Even if the 0.2% proof stress is 28.5 kgf / mm ² or less, by reducing the 0.2% proof stress, the above-mentioned shape fixability can be further improved.

In order to prevent other press forming qualities intended in the present invention, that is, to suppress the occurrence of material cracking, while maintaining the above-mentioned yield strength, {211 } It is essential to control the degree of integration of crystal planes to a specific value.

First, in order to improve the growth of crystal grains under the annealing conditions before pressing intended in the present invention, O and B are controlled to be below a specific value and the mold fit during press molding is improved. In order to achieve this, it is necessary to control Si and Ni to below a specific value, respectively, as follows. (2) Oxygen: Oxygen is one of the impurities inevitably mixed in the present alloy. When this oxygen content increases, the amount of oxide-based nonmetallic inclusions in the alloy increases, and these inclusions
In particular, it inhibits the crystal grain growth during annealing before press molding at a temperature of 720 to 790 ° C. for 40 minutes or less. That is, when the amount of O exceeds 0.0020%, the above grain growth inhibiting effect becomes remarkable, and 28.5 kg is obtained after annealing before press forming.
Since the 0.2% proof stress of f / mm ² or less cannot be obtained, 0.002
The upper limit was 0%. The lower limit is not specified, but is 0.0001% from the economical aspect of melting.

(3) Boron: Boron is contained in this alloy.
Improves hot workability, but when the content is high, it segregates at the grain boundaries of the recrystallized grains formed during annealing before pressing, making it difficult for the grain boundaries to move, and as a result the grain growth is hindered. ,
The required 0.2% proof stress cannot be obtained after annealing before press forming. In particular, under the annealing conditions before pressing specified in the present invention, such a grain growth inhibitory action is strong, and this action does not work uniformly for all the crystal grains, resulting in significant mixed grains. It shows a structure and causes uneven elongation of the material during press molding.

Further, this B also increases the degree of integration of the {211} crystal planes, which causes cracks in the material skirt, after annealing. If the amount of B exceeds 0.0005%, the above-mentioned grain growth inhibitory effect becomes remarkable, and the grain size of 28.5 kgf / mm ² or less becomes 0.2.
% Yield strength cannot be obtained, and problems such as elongation unevenness at the time of pressing also occur, and the degree of integration of {211} crystal faces also exceeds the upper limit specified in the present invention. From the above, the upper limit of B content is
It was set to 0.0005%.

(4) Silicon: Silicon is used as a deoxidizing element when the alloy is melted. If it exceeds 0.05%, a Si oxide film is formed on the alloy surface during annealing before pressing. Due to this oxide film, the compatibility with the mold at the time of press molding becomes poor, and the alloy comes to bite the mold. Therefore
The upper limit of the amount of Si was set to 0.05%. Even if Si is 0.05% or less, the fit between the alloy plate and the mold can be further improved by further reducing the Si content. The lower limit is not particularly specified, but is 0.001% or more from the economical aspect of melting.

(5) Nitrogen: Nitrogen is an element that is inevitably mixed when the alloy is melted. If it exceeds 0.0015%, N is concentrated on the alloy surface during annealing before pressing, and this alloy surface The nitride makes the alloy less compatible with the mold at the time of press molding, and causes the alloy plate to bite the mold. Therefore, the upper limit of the amount of N is set to 0.0015%. The lower limit is not specified, but it is 0.0001% or more from the economical aspect of melting.

The invar alloy for a shadow mask according to the present invention has a basic composition of Fe--Ni as described above with a specific amount of B, O, Si, N, and 0.2 after annealing before pressing.
% Proof stress is 28.5 kgf / mm ² or less and the degree of accumulation of {211} crystal faces is 16% or less. In addition to the above composition, C: 0.0001 to 0.0050%, Mn : 0.0
It is preferably within the range of 01 to 0.35% and Cr: 0.001 to 0.05%.

By controlling the components as described above and setting the 0.2% proof stress after the pre-press annealing within the stipulations of the present invention, it is possible to suppress the galling of the alloy during the press molding,
In addition, although the shape fixability can be set to an excellent level, the press molding quality still has a problem of material cracking. Therefore, in order to solve such a problem, the present inventors have variously changed the crystal orientation of the present alloy sheet having the components and 0.2% proof stress within the rules of the present invention to crack the material during press forming. I investigated the relationship with. As a result, in order to suppress cracking of this alloy material,
In addition to the regulation of 2% proof stress, it was found that it is effective to control the degree of integration of {211} crystal planes to a specific value or less.

FIG. 1 shows the relationship between alloy plate cracking during press forming, the degree of accumulation of {211} crystal faces, and 0.2% proof stress for alloy plates having the components shown in FIG.
The degree of integration of the {211} crystal plane was measured by measuring the relative X-ray diffraction intensity ratio of the (422) diffraction plane of the alloy sheet after annealing before pressing to (11
1), (200), (220), (311), (33
It was determined by dividing by the sum of the relative X-ray intensity ratios of the diffraction surfaces of 1) and (420). Here, the relative X-ray diffraction intensity ratio is the X-ray diffraction intensity measured on each diffraction surface divided by the theoretical X-ray diffraction intensity of that diffraction surface. For example (11
1) The relative X-ray diffraction intensity ratio of the diffraction plane is the X-ray diffraction intensity of the (111) diffraction plane divided by the theoretical X-ray diffraction intensity of the (111) diffraction plane. The integration degree of the {112} crystal plane was measured by measuring the X-ray diffraction intensity of the (422) diffraction plane which is equivalent to the {211} plane in terms of orientation. From Figure 1 like this
0.2% proof stress is 28.5 kgf / mm ² or less and {211}
When the degree of integration of crystal planes is 16% or less, cracking of the alloy plate does not occur during press forming, and the excellent effect intended by the present invention is exhibited. From the above examination results, the degree of integration of {211} crystal planes was set to 16% as a condition for suppressing cracking of alloy sheets.
The following was set.

As described above, the O, B, and
Specified Si and N and 0.2% proof stress after annealing before pressing,
The press molding quality intended in the present invention can be made excellent by the degree of integration and regulation of the {211} crystal plane.

A method for making the degree of integration of {211} crystal planes 16% or less will be described with reference to FIG. Figure 2
Are those obtained by annealing the hot-rolled steel strip of the alloy of the present invention and those not annealed by cold rolling-annealing (890 ° C. × 1 min).
-Finish cold rolling (21%)-Pre-press annealing (750 ° C x
It shows the degree of integration of {211} crystal faces and the elongation value in the tensile test of the alloy plate after the process of 15 min). When the hot-rolled sheet is annealed at 910 to 990 ° C, the degree of integration of {211} crystal faces is 16% or less. Therefore, in the present invention, the temperature range in the hot-rolled sheet annealing is set to 910 to 990 as a condition for making the degree of integration of {211} crystal planes 16% or less.
℃ was set.

Such hot-rolled sheet annealing in the present invention is exhibited when the hot-rolled steel strip of the present alloy is sufficiently recrystallized before the hot-rolled sheet annealing. Further, in order to obtain the degree of integration of {211} crystal planes intended in the present invention, the slab homogenization heat treatment after slabbing is not preferable in producing the present alloy. For example, the above homogenizing heat treatment is 1200 ° C. or higher, 1
When the treatment is performed for 0 hours or longer, the degree of integration of the {211} crystal plane exceeds the specified value of the present invention, and therefore such treatment must be avoided.

Although the mechanism by which the degree of integration of {211} crystal planes exceeds 16% and the material cracks during press molding has not been clarified, the C direction (material) shown in FIG. In the value of the elongation in the direction perpendicular to the rolling direction), when the degree of integration of the {211} crystal plane is high, the value of this elongation shows a low value. It is presumed that cracking may occur due to the lowering of the elongation value and the lowering of the breaking limit when the value rises.

While the degree of integration of {211} crystal planes is 16% or less, the 0.2% proof stress after annealing before pressing is 28.5 kgf /
In order to reduce the size to mm ² or less, it is important to control the finish cold rolling rate, the austenite grain size before that, and the annealing condition before pressing in addition to the above-mentioned regulations.

FIG. 3 shows a tensile test of an alloy plate produced by the manufacturing process of the hot-rolled steel strip of the alloy of the present invention.
This is a measurement of 0.2% proof stress. Annealing after cold rolling changes the temperature to obtain a predetermined austenite grain size.

From FIG. 3, the finish cold rolling rate (R%) is 1
6-75%, and 6.38D-133.9 ≦ R ≦ 6.3 depending on the austenite crystal grain size (Dμm) before finish cold rolling.
By setting 8D-51.0, 0.2% proof stress is 28.5kgf
/ Mm ² or less.

R is less than 16%, or 6.38D-1
In the case of 33.9> R, the recrystallization is insufficient and the grain growth of the recrystallized grains is insufficient under the annealing condition before pressing specified in the present invention, so that the 0.2% proof stress is 28 .5 kgf /
Not suitable because it exceeds mm ² . On the other hand, if R exceeds 75%, or if R> 6.38D-51.0, 100% recrystallization occurs under the annealing conditions before pressing specified in the present invention, but the frequency of nucleation during recrystallization becomes too high. 0.2 because the crystal grains become finer
% Proof strength is over 28.5 kgf / mm ² , which is unsuitable.

From the above-mentioned relationship, 0.2% proof stress is 28.5 kgf / mm ^{2 under the} pre-press annealing condition which is a feature of the present invention.
As conditions for obtaining the following, R: 16 to 75%, 6.38
D-133.9 ≦ R ≦ 6.38 D-51.0 was defined. If the finish cold rolling ratio (R%) and the austenite grain size (D μm) before the finish cold rolling are within such ranges, {211} crystals on the surface of the alloy sheet after annealing before pressing are obtained. The degree of surface integration can be 16% or less.

The structure control of the alloy of the present invention as described above is performed by
Achieved by controlling the nucleation frequency during recrystallization by the combination of the grain size before finish cold rolling and the appropriate finish cold rolling ratio in addition to the texture control in hot-rolled sheet annealing. It is a thing. By optimizing the combination of D and R described above,
It is possible to lower the 2% proof stress. That is,
R: 21 to 70%, 6.38D-122.6 ≦ R ≦ 6.38D
By selecting R and D that satisfy the condition of −65.2,
The 0.2% proof stress can be set to 28.0 kgf / mm ² or less.

Further, R: 26-63%, 6.38D-10
By selecting R and D satisfying the condition of 8.0 ≦ R ≦ 6.38D−79.3, the 0.2% proof stress can be set to 27.5 kgf / mm ² or less. The austenite grain size before the finish cold rolling intended in the present invention is determined by annealing the hot-rolled steel strip in a hot-rolled sheet and annealing it after the subsequent cold-rolling at 860 to 950 ° C.
Then, it can be accurately obtained by appropriately applying 0.5 to 2 min.

In the present invention, the degree of accumulation of {211} crystal planes on the surface of the alloy sheet is 16% or less, and the 0.2% proof stress after annealing before pressing is 28.5 kgf / mm ² or less. In order to do so, in addition to the above regulations, it is important to control the annealing conditions before pressing. This will be described with reference to FIG. 4. FIG. 4 shows the composition, the annealing conditions of hot-rolled sheet, the austenite grain size before finish cold rolling, and the finish cold rolling ratio of alloy sheets within the scope of the present invention. It shows the relationship between the 0.2% proof stress after pre-press annealing and the degree of integration of {211} crystal faces, and the temperature (T) and time (t) of pre-press annealing.

As is apparent from FIG. 4 as described above,
Even if the hot rolled sheet annealing conditions, the finish cold rolling austenite grain size and the finish cold rolling rate are within the scope of the present invention,
In case of T <−53.8log t + 806, recrystallization is not sufficient, 0.2% proof stress is over 28.5 kgf / mm ² , and {2
The degree of integration of the 11} crystal plane is also over 16%, which is unsuitable. Further, when T exceeds 790 ° C. or t exceeds 40 min, the {211} crystal plane is developed and the degree of integration of this crystal plane exceeds I6%, which is not suitable. From these relationships, the 0.2% proof stress and {2
11] As a condition for obtaining the degree of integration of crystal planes, T: 720 to 720
790 ° C., t: 2 to 40 min, T ≧ −53.8 log t + 8
06 has been set.

It is to be noted that FIG. 5 shows an alloy plate produced by the manufacturing process shown in FIG. 5 using the alloy of the present invention (alloy No. 1) and the comparative alloy (alloy No. 7 and No. 8). Changes in 0.2% proof stress and degree of integration of {211} crystal planes with annealing time are shown. The conditions for hot-rolled sheet annealing, the austenite grain size before finish cold rolling and the finish cold rolling rate are within the scope of the present invention.

According to FIG. 5 as described above, when the alloy of the present invention was used, within the pre-press annealing conditions within the scope of the present invention shown in FIG. 4, 0.2% proof stress and {211} crystal plane were obtained. Is within the range specified by the present invention. On the other hand, in the case of the comparative alloy, 0.2% even when annealed at 750 ° C.
The yield strength is more than 28.5 kgf / mm ² , and the degree of integration of {211} crystal planes is also more than the specified value of the present invention, and it is clear that there is a problem in press formability. As described above, in the present invention, it is understood that the composition of the alloy is extremely important in addition to the definition of the manufacturing method.

Further, the annealing before press forming in the present invention may be carried out before photoetching. In this case, if the annealing conditions before press forming are within the scope of the present invention,
The required photoetching quality can be ensured.

The alloy thin plate after annealing before press was {2
11) In addition to the above-described method, the method of controlling the degree of integration of crystal planes within the scope of the present invention includes the use of rapid solidification, texture control by controlling recrystallization in hot working, and the like.

[0046]

EXAMPLES The present invention as described above will be described in more detail with reference to specific examples as follows. (Example 1) Steel ladles composed of alloys No. 1 to No. 18 having the chemical components shown in the following Table 1 and Table 2 were prepared by ladle refining.

[0047]

[Table 1]

[0048]

[Table 2]

Each of the ingots shown in Tables 1 and 2 described above is a hot rolled steel strip obtained by slabbing, surface flaw removal, and hot rolling (heating at 1100 ° C. × 3 hr) after caring for each. Thereafter, hot-rolled sheet annealing (930 ° C.)-Cold rolling-annealing (conditions shown in Table 3) -finish cold rolling (reduction of 21%) was performed to obtain an alloy sheet having a sheet thickness of 0.25 mm. .. These hot-rolled steel strips were sufficiently recrystallized after hot-rolling. After these alloy sheets are made into flat masks by etching, the flat masks are annealed before press under the condition of 750 ° C. × 15 min, and then press-formed to obtain shape fixability, conformability with a die, and material. The occurrence of cracks was examined according to the evaluation criteria shown in Tables 1 and 2 (Alloy No. 1 to No. 18 are
No.1 to No.18). The tensile properties (0.2% proof stress and elongation in the direction perpendicular to the rolling direction) and the degree of integration of {211} crystal faces were examined after the pre-press annealing. Tensile properties are measured at room temperature. The integration degree of the {211} crystal plane was measured by the above-mentioned X-ray diffraction.

[0050]

[Table 3]

As is clear from the results shown in Tables 1 and 2, the composition of the components within the scope of the present invention and the degree of integration of {211} crystal faces within the scope of the present invention and 0.2% were obtained. Each of the materials No. 1 to No. 13 that have proof stress shows an excellent level of press molding quality.

On the other hand, each of the materials No. 14 and No. 16 has a Si content and an N content exceeding the stipulations of the present invention, and there is a problem in compatibility with the mold. Material No.1
No. 5 is the case where the amount of O exceeds the regulation of the present invention, the 0.2% proof stress is over 28.5 kgf / mm ² , the shape fixability is inferior, and the cracking of the alloy plate occurs, so the press forming quality is high. Clearly there is a problem. In addition, No. 17 and No. 18 are the cases where only the B content and the B content and the O content exceed the regulations of the present invention, and the 0.2% proof stress is over 28.5 kgf / mm ² . The shape fixability is inferior. Furthermore, the degree of integration of the {211} crystal planes of these comparative alloys exceeds the value specified in the present invention, cracking of the alloy plate has occurred, and there is a problem in press molding quality.

As is apparent from the above description, the composition of components within the scope of the present invention and {21 within the scope of the present invention.
It is clear that the Fe-Ni alloy thin plate for a shadow mask having an excellent level of press-forming quality intended by the present invention can be obtained by adjusting the degree of integration of 1} crystal planes and the 0.2% proof stress.

(Example 2) Using the hot-rolled steel strips of alloys No. 1, No. 3, No. 5, No. 9, and No. 12 used in the above-mentioned Example 1, the hot-rolled sheet was annealed thereafter. Was performed under the conditions shown in Table 4 below, and those not carried out in the following.
Annealing (890 ° C x 1 min) -finish cold rolling (reduction ratio 21
%) To obtain an alloy plate having a plate thickness of 0.25 mm.

[0055]

[Table 4]

After each alloy plate as described above is formed into a flat mask by etching, the flat mask is exposed to 750 ° C.
Material No. 19 ~ by annealing before press under the condition of × 15min
I got No.23. Next, press molding was performed and the press molding quality shown in Table 3 was examined. The method of measuring each characteristic value in Table 3 is the same as in Example 1.

As is clear from the results shown in Table 4 above, the component composition within the range of the present invention, the degree of accumulation of {211} crystal faces and 0.2% proof stress and the finish cold within the range of the present invention. It has the austenite grain size before rolling, finish cold rolling rate and pre-press annealing conditions, and the hot-rolled sheet annealing conditions are all press-formed for materials No. 19 and No. 20 within the scope of the present invention. The quality shows an excellent level.

On the other hand, each of the materials No. 21 to No. 23 has a hot-rolled sheet annealing temperature lower than the lower limit, higher than the upper limit of the present invention, and not hot-rolled sheet annealed. However, in all materials, the degree of integration of {211} crystal planes exceeds the upper limit specified in the present invention, and the alloy plate is cracked during press forming. Furthermore, in material No. 23, the 0.2% proof stress is also over 28.5 kgf / mm ² , and there is a problem with the shape fixability during press molding.

As described above, in order to set the degree of integration of {211} crystal planes within the range of the present invention, it is important to set the hot-rolled sheet annealing within the range of the present invention.

(Example 3) Alloy No. 1 used in Example 1
No.2, No.4, No.6, No.7, No.9, No.11, No.12, No.13
And using No. 18 hot-rolled steel strip, hot-rolled sheet annealing (930 ° C) -cold rolling-annealing (1 at the temperature shown in Table 4
Finish cold rolling (implemented at a reduction ratio shown in Table 3) was performed to obtain an alloy plate having a plate thickness of 0.25 mm. After these alloy plates were made into flat masks by etching, the flat masks were annealed before press under the condition of 750 ° C. × 15 min to obtain materials No. 24 to No. 61. Next, press molding was performed and the press molding qualities shown in the following Tables 5 and 6 were examined. The measuring method of each characteristic value in Table 4 is the same as that of the first embodiment.

[0061]

[Table 5]

[0062]

[Table 6]

As is clear from the results shown in Tables 5 and 6, the austenite grains before the finish cold rolling were performed even in the case of the component composition within the scope of the present invention, the hot rolled sheet annealing conditions and the pre-press annealing conditions. Material No.25 to No.30, No.33, No.36 whose diameter and finish cold rolling rate are within the range specified by the present invention
~ No.38, No.42 ~ No.61 are all {211}
The degree of integration of crystal planes is less than 16%, especially material No. 25,
No.30, No.33, No.36, No.42, No.44, No.4
Each of No. 5, No. 49, No. 55, No. 58, and No. 61 is within the range of Region 1 of the present invention, and the 0.2% proof stress is 28.5 kgf /
mm ² or less, material No. 26, No. 28, No. 29, No. 43, No. 4
Each of No. 7, No. 50, No. 54, No. 60 and No. 38 is within the range of Region 2 of the present invention, and the 0.2% proof stress is 28.0 kg.
f / mm ² or less, material No. 27, No. 46, No. 48, No. 51, N
The materials of o.52, No.53, No.56, No.57, No.59 and No.37 are within the range of Region 3 of the present invention, and the 0.2% proof stress is 27.5kgf / mm. ^The yield strength of 0.2% or less, which is the target of the present invention, is obtained, and all of these materials show an excellent level of press moldability. Also, as mentioned above,
It can be seen that the shape fixability can be made to a more excellent level by the reduction of the 0.2% proof stress.

On the other hand, materials No. 24, No. 31, No. 3
Each of No. 2, No. 34, No. 35, No. 39, and No. 40 has one or both of the austenite grain size before the finish cold rolling and the finish cold rolling rate defined by the present invention. , The 0.2% proof stress and / or the degree of integration of {211} crystal planes exceeds the regulation of the present invention, and at the time of press molding,
There is a problem in one or both of shape fixability and cracking of the alloy plate.

Material No. 41 is the case where the annealing condition before finish cold rolling is 850 ° C. for 1 min, the austenite grain size is 10.0 μm in such annealing, and the subsequent finish cold rolling is performed. 0.2% even if the rolling rate is 15%
The yield strength is more than 28.5 kgf / mm ² , and the shape fixability during press molding intended by the present invention is not obtained.

As described above, even in the case of the component composition within the scope of the present invention, the hot rolled sheet annealing conditions and the pre-press annealing conditions, the austenite grain size before the finish cold rolling and the finish cold rolling rate are within the scope of the present invention. It is understood that the internal content is necessary to obtain the press molding quality intended in the present invention.

Example 4 Alloy No. 1 used in Example 1
Using No.4, No.17, No.18, No.9, No.10 and No.12 hot rolled steel strips, hot rolled sheet annealing (930 ° C) -cold rolling-annealing (890 ° C) X1 min) -finish cold rolling (reduction ratio 21%) was performed to obtain an alloy plate having a plate thickness of 0.25 mm. After these alloy plates were made into flat masks by etching, the flat masks were annealed before press under the conditions shown in Table 7 below to obtain materials No. 62 to 79. Then, press molding was performed and the press molding quality shown in Table 7 was examined. The measuring method of each characteristic value in Table 7 is the same as that of the first embodiment.

[0068]

[Table 7]

As is clear from the results shown in Table 7, even in the case of the component composition, hot rolling conditions, austenite grain size before finish cold rolling and finish cold rolling ratio within the scope of the present invention, before pressing Material No.62, No.64, No.71 to No.79 and No.6 whose annealing conditions (temperature, time) are within the scope of the present invention
The degree of integration of {211} crystal planes for each of the 5 materials is 16%
Below, 0.2% proof stress is also within the regulation of the present invention, and all materials show excellent press molding quality.

On the other hand, the materials No. 66, No. 67, and No. 68 each have a temperature in the pre-press annealing that is less than the lower limit, exceeds the upper limit, and exceeds the upper limit in time. In all the materials, the degree of integration of the {211} crystal plane exceeded 16%, and the alloy cracked. In material No. 66, the temperature is below the lower limit, so 0.2
The% yield strength is 28.5 kgf / mm ^2, and there is a problem with the shape fixability during press molding.

Material No. 63 is a conditional expression (T ≧ −53.8) consisting of temperature (T) and time (t) in pre-press annealing.
log t + 806), 0.2% proof stress is over 28.5 kgf / mm ² and there is a problem in shape fixability during press forming, and the degree of accumulation of {211} crystal faces is over 16%. As a result, the alloy plate is cracked during press forming.

Each of the materials No. 69 and No. 70 is the case where the comparative alloy is used.
Even when the pre-press annealing of min is performed, the 0.2% proof stress is more than 28.5 kgf / mm ² , and there is a problem in shape fixability during press forming. Further, in these materials, the degree of integration of {211} crystal planes is more than 16%, and the alloy plate is cracked during press forming.

As described above, even in the case of the component composition, the hot rolled sheet annealing conditions, the austenite grain size before the finish cold rolling and the finish cold rolling ratio within the scope of the present invention, the annealing conditions before the press are set according to the present invention. It is understood that the content within the range is necessary for obtaining the press molding quality intended in the present invention.

(Example 5) Alloy Nos. 1 and N used in the examples
Annealing of hot-rolled sheet (930 ℃) using hot-rolled steel strip of o.4
—Cold Rolling—Annealing (890 ° C. × 1 min) —Finishing Cold rolling (reduction of 21%) was performed to obtain an alloy plate having a plate thickness of 0.25 mm. These alloy sheets were annealed before press under the conditions shown in Table 8 below to obtain No. 80 to No. 82 materials. After forming a flat mask by subsequent etching, press molding,
The press molding quality shown in Table 6 was examined. The method of measuring each characteristic value in Table 8 is the same as in Example 1. Further, the etching property was examined by visually observing the occurrence of unevenness in the flat mask after etching.

[0075]

[Table 8]

As is clear from the results shown in Table 8 above, the composition within the scope of the present invention, the hot rolling conditions, the austenite grain size before finish cold rolling, the finish cold rolling rate and the pre-press annealing conditions were determined. Materials No.80 to No.82 within the scope of the present invention
Each of the above materials has good etching property without unevenness, and the degree of integration of {211} crystal faces is 16% or less.
The 2% proof stress is also within the regulation of the present invention, and all materials show excellent press molding quality.

As described above, the composition of components within the scope of the present invention, the conditions of hot-rolled strip annealing, the austenite grain size of the finish cold-rolled surface, the finish cold-rolling ratio and the annealing conditions before pressing are within the scope of the present invention. It is necessary in order to obtain the press molding quality intended in the present invention, and after the annealing before pressing, even if etching is performed, the obtained flat mask has no unevenness and the required etching. It is understood that sex is obtained.

As is clear from Examples 1 to 5, when the degree of integration of {211} crystal faces exceeds 16%, the elongation in the direction perpendicular to the rolling direction after the pre-press annealing is the present invention. It is lower than the example, and the degree of integration of {211} crystal planes is high,
It is presumed that this elongation value decreases and cracking occurs during press molding.

[0079]

According to the present invention as described in detail above,
Excellent press formability, and annealing before pressing is 720 ℃ to 7 ℃.
The required press-molding quality even at a low temperature of 90 ° C and a short annealing time of 40 min or less, that is, excellent shape fixability at the time of molding, good mold compatibility, and suppression of material cracking. Since it is possible to provide an Fe-Ni-based Invar alloy thin plate for a shadow mask and a method for producing the same, it is possible to provide industrially advantageous effects, and it is a large invention.

Furthermore, according to the present invention, the required etching quality and press molding quality can be obtained even if annealing before press molding is performed before etching, so that the CRT maker omits annealing before pressing. Since it is possible to provide an Fe-Ni-based Invar alloy thin plate for a shadow mask, it is possible to provide an industrially advantageous effect, which is a large invention.

[Brief description of drawings]

FIG. 1 is a table showing the relationship between cracking during press forming, the degree of accumulation of {211} crystal faces, and 0.2% proof stress after annealing before pressing.

FIG. 2 is a chart showing the relationship between the degree of integration of {211} crystal faces, the elongation in the direction perpendicular to the rolling, and the annealing temperature of the hot-rolled sheet.

FIG. 3 is a table showing the relationship between 0.2% proof stress after pre-press annealing, austenite grain size before finish cold rolling, and finish cold rolling rate.

FIG. 4 is a table showing the relationship between 0.2% proof stress after pre-press annealing, the degree of integration of {211} crystal faces, and pre-press annealing conditions.

FIG. 5 is a table showing the relationship between 0.2% proof stress after pre-press annealing, the degree of integration of {211} crystal faces, and pre-press annealing conditions.

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[Procedure amendment]

[Submission date] February 10, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0028

[Correction method] Change

[Correction content]

FIG. 1 shows the relationship between alloy plate cracking during press forming, the degree of accumulation of {211} crystal faces, and 0.2% proof stress for alloy plates having the components shown in the figure.
The degree of integration of the {211} crystal plane was measured by measuring the relative X-ray diffraction intensity ratio of the (422) diffraction plane of the alloy plate after annealing before pressing (11
1), (200), (220), (311), (33
Relative X of each diffraction surface of 1), (420) and (422)
It was obtained by dividing by the sum of the line intensity ratios. Where relative X
The line diffraction intensity ratio is the X-ray diffraction intensity measured on each diffraction surface divided by the theoretical X-ray diffraction intensity of that diffraction surface.
For example, the relative X-ray diffraction intensity ratio of the (111) diffraction plane is (11
1) X-ray diffraction intensity of the diffractive surface divided by theoretical X-ray diffraction intensity of the (111) diffractive surface. The measurement of the integration degree of the {112} crystal plane is equivalent to the {211} plane in terms of orientation (42
2) The measurement was performed by measuring the X-ray diffraction intensity of the diffraction surface. As shown in FIG. 1, the 0.2% proof stress is 28.5 kgf / mm ² or less, the degree of integration of {211} crystal faces is 16% or less, and the alloy sheet is not cracked during press forming. The excellent effect intended by the present invention is exhibited. From the above examination results, the degree of integration of {211} crystal faces was determined to be 16% or less as a condition for suppressing cracking of the alloy plate.

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[Procedure amendment]

[Submission date] April 16, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0054

[Correction method] Change

[Correction content]

[0054] If used in (Example 2) Example 1 described above
The hot-rolled steel strip of gold No. 1 was used to anneal the hot-rolled sheet thereafter.
In the following, cold rolling-annealing (890 ° C x 1 min) -finish cold rolling (21% rolling reduction) were carried out for those that were carried out under the conditions shown in (1) and alloy sheets with a thickness of 0.25 mm were obtained. It was

[Procedure Amendment 2]

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[Correction target item name] 0060

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[Correction content]

(Example 3) Alloy No. 1 used in Example 1
No.2, No.4, No.6, No.7, No.9, No.11, No.12, No.13
And using No. 8 hot rolled steel strip, hot rolled sheet annealing (930 ° C.)-Cold rolling-annealing (1 at the temperature shown in Table 4)
Finish cold rolling (implemented at the rolling reduction shown in Table 3) was performed to obtain an alloy plate having a plate thickness of 0.25 mm. After these alloy plates were made into flat masks by etching, the flat masks were annealed before press under the condition of 750 ° C. × 15 min to obtain materials No. 24 to No. 61. Next, press molding was performed and the press molding qualities shown in the following Tables 5 and 6 were examined. The measuring method of each characteristic value in Table 4 is the same as that of the first embodiment.

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[Figure 5]

Claims (4)

[Claims] 1. Wt%, Ni: 34-38%, Si: 0.05
% Or less, B: 0.0005% or less, O: 0.0020% or less, N: 0.0005% or less, the balance consists of unavoidable impurities and Fe component composition, and is an alloy after annealing before press forming. A shadow mask excellent in press formability, which has a 0.2% proof stress of 28.5 kgf / mm ² or less in a plate and an accumulation degree of {211} crystal planes on the surface of an alloy plate of 16% or less. Fe-Ni alloy thin plate for use. 2. A hot-rolled steel strip of a low-thermal expansion alloy having the components according to claim 1 is annealed by hot-rolling, followed by cold rolling and subsequent recrystallization annealing, and then finish cold rolling. At the time of manufacturing in the process of applying, the hot rolled sheet annealing is performed at 910 to 990 ° C.
The reduction ratio (R)% in the finish cold rolling is applied within the range of the region I shown in FIG. 3 according to the austenite grain size D (μm) after the recrystallization annealing described above, and before the subsequent press forming. Annealing is performed at temperature (T ° C) of 720 to 790 ° C for time (tmin)
Is 2 to 40 min and T ≧ −53.8 logt + 806 so that the alloy plate after annealing is 0.2
% Yield strength of 28.5 kgf / mm ² or less and adjusting the degree of integration of {211} crystal faces to 16% or less, a method for producing an Fe-Ni alloy thin plate for a shadow mask excellent in press formability . 3. A hot-rolled steel strip of a low thermal expansion alloy having the components according to claim 1 is subjected to hot-rolled sheet annealing, followed by cold rolling and subsequent recrystallization annealing, and then finish cold rolling. When manufacturing in the process of applying, the hot-rolled sheet is annealed at 910 ° C.
Rolling ratio (R%) in finish cold rolling performed at ~ 990 ° C
Is the austenite grain size D (μ
m) in the region II shown in FIG. 3, and the subsequent annealing before press forming has a temperature (T ° C.) of 720 to 79.
0 ° C., time (tmin) is 2 to 40 min, and T ≧ −53.8 lo
By applying under the condition of satisfying g t +806, the 0.2% proof stress of the annealed alloy plate is 28.0 kgf / mm ² or less,
A method of manufacturing an Fe-Ni alloy thin plate for a shadow mask excellent in press formability, which comprises adjusting the degree of integration of {211} crystal faces to 16% or less. 4. A hot-rolled steel strip of a low-thermal expansion alloy having the components according to claim 1 is annealed by hot-rolling, followed by cold rolling and subsequent recrystallization annealing, and then finish cold rolling. When manufacturing in the process of applying, the hot-rolled sheet is annealed at 910 ° C.
Rolling ratio (R%) in finish cold rolling performed at ~ 990 ° C
Is the austenite grain size D (μ
m) according to the area III shown in FIG.
The temperature (T ° C) for the subsequent annealing before press forming is 720
~ 790 ° C, time (tmin) is 2-40 min and T≥-5
By applying under the condition satisfying 3.8 log t + 806,
A shadow mask with excellent press formability, characterized in that the alloy sheet after annealing has a 0.2% proof stress of 27.5 kgf / mm ² or less and the degree of integration of {211} crystal faces is adjusted to 16% or less. For manufacturing Fe-Ni alloy sheet for automobile.