JP2950595B2 - Stainless steel for cathode ray tube electron gun and electron gun for cathode ray tube using the same - Google Patents

Description

The present invention relates to a stainless steel material for a cathode ray tube electron gun and an electron gun for a cathode ray tube using the same.

(Prior art) Electron guns used in cathode ray tubes such as color picture tubes include:
A plurality of electrodes are arranged such as an electrode for controlling the emission of an electron beam from a cathode, an electrode for accelerating and further converging or deflecting the emitted electron beam, and each of them has an electron beam passage hole. .

In general, a high voltage is applied to the electrodes arranged in the electron gun in order to form an electrostatic lens between the electrodes, and it is considered that the larger the potential difference, the more preferable in terms of convergence and acceleration. I have. Therefore, it is desired that these electrodes have no harmful defects such as scratches and burrs that adversely affect the withstand voltage. Further, in order to form a lens having no distortion, it is desired that the constituent materials of these electrodes are non-magnetic.

For this reason, conventionally, as an electrode material for an electron gun, an austenitic stainless steel made non-magnetic by heat treatment, for example, SUS 304 or the like has been used. Such an electrode material is subjected to casting, hot working, cold rolling, etc., to form a strip having a predetermined thickness, and then to processing such as punching and drawing into a predetermined shape, further deburring, After being subjected to cleaning, heat treatment, etc., it is incorporated into an electron gun.

(Problems to be Solved by the Invention) However, the conventional electrode constituting materials such as SUS 304 described above, when performing a punching process such as drilling,
The disadvantage is that the burr generated around the hole is large, which not only shortens the life of the mold, but also disturbs the electric field of the electron gun and becomes a source of contamination such as foreign matter. There was a problem that it was easy to have an adverse effect. In addition, there is also a problem that softening due to heat treatment before assembling easily causes problems such as deformation of parts.

Also, by reducing the diameters of the first and second grids close to the cathode after increasing the precision, focus characteristics are improved and clear image quality can be obtained. However, the strength was not so high that these requirements could not be satisfied.

The present invention has been made in order to address such problems, and has improved mechanical strength, heat resistance, and the like, and a stainless steel material for a non-magnetic cathode ray tube electron gun that has improved workability such as punching properties and the like. An object of the present invention is to provide a cathode ray tube electron gun using the same.

[Constitution of the Invention] (Means and Actions for Solving the Problems) That is, the stainless steel material for a cathode ray tube electron gun of the present invention
13-25 wt% Cr, 6-20 wt% Ni, 1.5 wt% Mn
Less than 1.0% by weight of Si, 0.001 to 0.3% by weight of C, IV
An alloy containing 0.1 to 5% by weight of at least one element selected from the group a elements and the group Va elements, and the remainder substantially consisting of Fe excluding impurities, wherein the alloy structure includes Containing carbides of at least one element selected from the group consisting of element and Va group element as dispersed particles in the range of 10,000 to 5,000,000 particles / mm ² , or as dispersed particles having an average size of 10 μm or less. It is characterized by the following.

Further, the electron gun for a cathode ray tube of the present invention is a cathode ray tube electron gun, comprising: a cathode portion for emitting an electron beam; and a plurality of electrodes having a passage hole for the electron beam and controlling the electron beam. A part or all of the electrode is made of the stainless steel material for a cathode ray tube electron gun.

The reasons for limiting the composition of the stainless steel material for an electron gun of the present invention are as follows.

Cr is an element that enhances corrosion resistance. If it is less than 13% by weight, sufficient corrosion resistance cannot be obtained, and if it exceeds 25% by weight, the austenite phase becomes unstable. A more preferred content of Cr is in the range of 15 to 19% by weight.

Ni is an element that makes a uniform austenite phase appear. If it is less than 6% by weight, it becomes difficult to make a uniform austenite phase appear, and even if it exceeds 20% by weight, no further effect can be obtained. Not only that, the cost will increase. A more preferred content of Ni is in the range of 11-15% by weight.

Mn is necessary for deoxidation and for improving hot workability, but when it is 1.5% by weight or more, it has a bad influence on emission characteristics. On the other hand, if the content of Si is 1.0% by weight or more, the workability is reduced.

C precipitates at least one element selected from the group IVa group element and the group Va group element as a carbide, improves mechanical strength and heat resistance, and imparts appropriate punching properties. The content is in the range of 0.001 to 0.3% by weight.

If the content of C is less than 0.001% by weight, the effect of improving strength and heat resistance cannot be sufficiently obtained. On the other hand, if the content of C exceeds 0.1% by weight, workability decreases and mechanical strength becomes too high. The pressability to various parts shapes deteriorates remarkably. A more preferred content of C is in the range of 0.01 to 0.1% by weight.

One kind of element selected from the group IVa element and the group Va element at least precipitates as carbides and exists as dispersed particles in the alloy structure, thereby improving mechanical strength and heat resistance, and improving the mechanical strength and heat resistance. By providing punching properties and fixing dissolved gas, the amount of gas released in a vacuum is reduced. It may be deposited or crystallized as another compound such as a nitride or an intermetallic compound with Fe. As the element, it is particularly preferable to use at least one element selected from Nb, Ta, and Zr from the viewpoint of the effect.

The content of these IVa group elements and Va group elements is 0.01
If the content of these elements is less than 0.01% by weight, these additional elements will form a solid solution in the parent phase and the amount of precipitation as carbides will be insufficient. The effect of improving the performance and the effect of reducing the amount of released gas cannot be sufficiently obtained. On the other hand, when the content exceeds 5% by weight, the workability is reduced, and the mechanical strength is too high, so that the rolling process becomes difficult and the pressability to various parts shapes is remarkably deteriorated. A more preferred content of Group IVa and Va elements is in the range of 0.4 to 3% by weight.

The above-mentioned IVa group element and Va group element may be used in combination of plural kinds of elements, or may be used alone. The content when a plurality of types of elements are used in combination is within the above range in total.

Further, the content of Al as an impurity in the alloy composition was 01.
Less than 1.0 wt%, Ti content is less than 1.0 wt%, Cu content is 1.0
It is preferred that the amount is less than the weight%. When the content of these impurity elements is more than the above numerical values, all of them adversely affect emission characteristics. Further, the content of S is set to less than 0.01% by weight from the viewpoint of the amount of released gas.

As described above, the stainless steel material for an electron gun of the present invention
Dispersed particles containing carbides of a group a element and a group Va element are present in the alloy structure.

The dispersed particles preferably have a size of 10 μm or less, and dispersed particles having such a size are 10,000 to 50,000.
It is preferable to be present in the range of 00 pieces / mm ² . When the size of the dispersed particles exceeds 10 μm, the effect of improving the strength and heat resistance cannot be sufficiently obtained, and the punching property is reduced, and the hole burr tends to increase. Here, the size of the dispersed particles means the diameter of the smallest circle containing the dispersed particles. Further, even number less than 10000 / mm ² of the dispersed particles, the strength and not the effect of improving heat resistance can not be obtained sufficiently, also reduces the punching property, large hole burrs and cracks angle becomes smaller Cheap.

(Example) Next, an example of the present invention is described.

Examples 1 to 6 First, alloy components having the compositions shown in Table 1 were respectively melted to cast ingots, and then cast at a temperature of 1200 ° C.
Billets of 0 mm × 600 mm × L were prepared.

Next, the thickness of each billet, after hot rolling at a temperature of 1150 ° C. to 4 mm, to a thickness of 0.25 mm by repeated cold working and annealing, further annealing at a temperature of about 950 ° C. for 30 minutes Then, a plate-shaped alloy sample was prepared for each, and was subjected to characteristic evaluation described later.

On the other hand, for comparison with the present invention, a plate-like sample was similarly prepared using a conventional stainless steel having a composition shown in Table 1 and was subjected to characteristic evaluation.

For each of the plate-shaped alloy samples obtained in the above Examples and Comparative Examples, hardness, tensile strength and elongation were first measured, and then heat-treated at a temperature of 1050 ° C. for 30 minutes. , The hardness, tensile strength and elongation were measured in the same manner.

In addition, the size and number of dispersed particles in each of the alloy samples after the heat treatment were measured in several visual fields from a 400-fold metallographic photograph. The size of the dispersed particles is indicated by an average value.

Further, the first grid and the second grid were punched as electron gun parts from each of the alloy samples after the heat treatment by press working, and the burr height and crack angle around the punched holes of the parts were measured. Further, the magnetic permeability and the gas release rate when heated at 800 ° C. for 30 minutes were measured by a flow rate method.

 Table 2 shows the above measurement results.

In the punching test, as shown in FIG. 1, the fractured surface 1 at the punched portion and the punched surface 2 were evaluated.
Is the angle of cracking, and the burrs 3
Was measured as the hole burr height. Here, when the crack angle θ is small, the height of the burr 3 increases, and the burr 3 easily falls down to the hole side, causing various problems.

As is clear from the results in Table 2, the stainless steel for an electron gun according to each embodiment is non-magnetic, has a high hardness, and
It can be seen that the hardness hardly decreases even after the heat treatment at 1050 ° C., the crack angle at the time of press punching is large, and the burr height is small. Also, the outgassing rate is low.

From the above, by assembling the electron gun for a cathode ray tube using the stainless steel material for an electron gun, it is possible to prevent an adverse effect on the electron beam characteristics, to improve the assemblability, etc., and to sharpen an image. Fine processing for improving the degree can be performed with high accuracy. Further, since the amount of released gas is reduced, product characteristics can be improved.

[Effects of the Invention] As described above, according to the stainless steel material for a cathode ray tube electron gun of the present invention, a material having high hardness, heat resistance, and excellent punching properties while satisfying nonmagnetic properties is provided. It is possible to do. Therefore, by using this as a material for forming an electrode for an electron gun to constitute an electron gun, it is possible to provide a high-quality electron gun for a cathode ray tube.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining an evaluation method of a punching test. 1 ... broken view, 2 ... punched surface, 3 ... burr, h ...
Burr height, θ: crack angle.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C22C 38/00-38/60 C22C 1/10 H01J 29/48

Claims (4)

(57) [Claims] (1) 13 to 25% by weight of Cr, 6 to 20% by weight of Ni, Mn
Less than 1.5% by weight, Si less than 1.0% by weight, C
% Alloy containing 0.1 to 5% by weight of at least one element carried from a group IVa element and a group Va element, and the balance substantially consisting of Fe excluding impurities. A carbide of at least one element selected from the group IVa element and the group Va element as dispersed particles from 10,000 to 5,000,000
A stainless steel material for cathode ray tube electron guns, characterized in that it is contained in the range of pcs / mm ² . (2) Cr is 13 to 25% by weight, Ni is 6 to 20% by weight, Mn
Less than 1.5% by weight, Si less than 1.0% by weight, C
% Alloy containing at least one element selected from the group IVa element and the group Va element in an amount of 0.1 to 5% by weight, with the balance being substantially Fe except for impurities. A stainless steel material for a cathode ray tube electron gun, comprising a carbide of at least one element selected from Group IVa and Group Va as dispersed particles having an average size of 10 μm or less. 3. The stainless steel material for an electron gun of a cathode ray tube according to claim 1, wherein an Al content as an impurity in the alloy composition is less than 0.1% by weight, a Ti content is less than 1.0% by weight, and a Cu content. Less than 1.0% by weight, S content 0.01% by weight
A stainless steel material for a cathode ray tube electron gun. 4. A cathode ray tube electron gun comprising: a cathode portion for emitting an electron beam; and a plurality of electrodes having a hole for passing the electron beam and controlling the electron beam. All claim 1 or claim 2
An electron gun for a cathode ray tube, comprising the stainless steel material for a cathode ray tube electron gun described above.