JPS607682B2 - Electrode device in metal fine particle production equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrode device in a metal fine particle manufacturing apparatus,
In particular, the present invention relates to means for preventing metal particles generated during arc discharge from adhering to electrodes and causing wear and tear of the electrodes.

A method of melting metals and alloys generally using arc discharge, namely tungsten or tritane (1% to 2%
When metals or alloys are arc melted in an atmosphere of inert gas (one or more gases such as helium, argon, etc.) using tungsten containing thorium oxide as an electrode, very few particles are generated. Therefore, the problem of the fine particles adhering to the electrodes and causing the electrodes to deteriorate due to wear and tear does not occur.

However, in arc melting, when metals or alloys are melted using hydrogen gas or a gas mixture with the above-mentioned inert gas as the atmospheric gas, the generated metal particles adhere to the electrodes, causing deformation and melting of the electrodes. Arc discharge for a long time was not possible because it would cause problems such as dripping.

The present invention has been made to eliminate the above-mentioned drawbacks, and its main purpose is to process metals or alloys in an atmosphere of hydrogen gas or a mixed gas of hydrogen gas and an inert gas (for example, helium, argon, etc.). An object of the present invention is to provide a means for an electrode device that prevents fine metal particles generated during arc melting from adhering to an electrode.

FIG. 1 shows an electrode device used in a conventional arc melting method, where 1 is an electrode made of pure tungsten or tritanium (tungsten containing thorium oxide), and 2 is an electrode support frame for fixing the electrode 1.

Metals or alloys that are soluble in water, such as iron, cobalt,
Consists of nickel or an alloy of two or more thereof.

9 is a water-cooled steel hearth coated with metal or alloy 10.

In such a configuration, an inert gas (one or more of helium, argon, etc.) is placed between the electrode 1 and the metal or alloy 10.
The metal or alloy 10 is heated and melted by causing arc discharge in a mixed gas atmosphere. At this time, problems due to fine particles adhering to the electrode do not occur in practice, except in the case of metals with high vapor pressure such as chromium and manganese. On the other hand, in the electrode device using this arc melting method, when arc discharge is performed in hydrogen gas or a mixture of hydrogen gas and inert gas, the activated hydrogen gas reacts with the molten metal, and metal fine particles are removed from the molten metal. A large amount is generated, and a portion of this adheres to the electrodes, causing wear and tear.

In order to solve this problem, a means for preventing metal fine particles from adhering to electrodes was invented, and examples thereof are shown in FIGS. 2 to 4.

Hereinafter, the electrode device of the present invention will be explained with reference to these drawings. FIGS. 2 and 3 show the electrode device shown in FIG. 1 in which the electrode 1 and the electrode support frame 2 are vertically installed, but the arc column 6 is tilted from the vertical direction due to an external factor, and metal fine particles are generated. This figure shows a means for preventing the adhesion of the liquid to the electrode. That is, in FIG. 2, the arc column 6 is tilted by blowing hydrogen gas or a mixed gas of hydrogen gas and inert gas from a gas pipe 7 toward the arc column 6 from one side of the arc column 6. . Furthermore, FIG. 3 shows a case where the arc column is tilted by lines of magnetic force generated from a permanent magnet, an electromagnet 8, etc. instead of a gas flow. According to this device, since the electrode 1 does not exist in that direction for the metal fine particles mainly generated in the upper direction, the metal fine particles are less likely to adhere to the electrode 1, and wear and tear of the electrode 1 can be prevented.

FIG. 5 shows another embodiment of the present invention, in which gas flows out around the haze electrode.

A first electrode la is fixed to an opening at the lower end of the electrode support frame 2, and two openings for the second electrode lb and the gas introduction pipe 4 are formed on the first electrode la. A discharge electrode 1 is iron-bonded to the second electrode lb, and a flange is formed on the entrance edge on the insertion side. Furthermore, a gas introduction pipe 4 disposed within the support frame 2 is also inserted. A first nozzle 3 is attached around the electrode 1 by being screwed onto the first electrode la. Here, the gap between the first nozzle 3 and the electrode 1 is substantially constant along the longitudinal direction of the electrode 1. A second nozzle 3a is arranged in the gap between the first electrode 3 and the first and second electrodes la, lb, and a plurality of openings are formed along the circumferential direction of the second nozzle 3a. Further, a gap is formed between the first electrode la and the first nozzle 3 in the vertical direction as well. In this configuration, one or more mixed gases of hydrogen, helium, and argon, for example, are introduced into the gas introduction pipe 4 and led out into the gap with the second nozzle 3a.

This led out gas passes through the gap with the first nozzle 3 through the opening formed in the second nozzle 3a, and is led out from the gap between the electrode 1 and the first nozzle 3. The derived gas flow forms a laminar flow around the electrode 1, and in particular forms a dense gas flow layer at its tip as shown by the dotted line in Figure 4, and the generated metal particles adhere to the electrode 1 and become thick. There is. Here, the reason why the distance between the first nozzle 3 and the electrode 1 is made constant is to form a laminar flow in the electrode 1 described above; if this distance is not constant, the derived gas flow will cause a vortex flow or This is because disturbance occurs and the effect of preventing metal fine particles from adhering to the electrode 1 is hindered. FIGS. 5 and 6 show how the electrode according to the present invention deteriorates due to wear and tear, and the arc discharge conditions are as follows.

Applied current 200A Applied voltage 26V Gas composition Hydrogen 40% Argon 60% In addition, tungsten electrodes are used for the electrodes.

Figures 1, 2, and 3 show the electrode before discharge, the electrode after continuous arc discharge for approximately 2 hours using the device shown in Figure 3, and the electrode after approximately 1 hour using the conventional device shown in Figure 1. It is a side view which shows the state of an electrode when arc discharge is performed continuously. In addition, Fig. 6 2 shows the electrode when arc discharge was performed continuously for about 2 hours using the electrode device shown in Fig. 4, and Fig. 6 1 and 3 show electrodes under the same conditions as Fig. 5 1 and 3, respectively. shows.

As is clear from these drawings, according to the present invention, wear and deterioration of the electrodes can be prevented by any of the electrode devices, and arc discharge can be performed for a long time.

As described above, according to the present invention, it is possible to prevent the metal particles generated during arc discharge from adhering to the electrode and wear and deteriorate the electrode, and it is possible to perform arc discharge for a long time, especially for long-term continuous discharge. It is valid.

In addition to using the embodiments of the present invention described above alone,
For example, the embodiments of the present invention may be combined in various ways, such as by applying the electrode device shown in FIG. 4 to the devices shown in FIGS. 2 and 3, thereby further improving the prevention of electrode wear and deterioration.

[Brief explanation of the drawing]

FIG. 1 is a side view showing a conventional electrode device, FIGS. 2, 3, and 4 are side sectional views showing an embodiment of the present invention, and FIGS. A side view showing the state of the electrodes produced by the device shown in FIG. 3 and the device shown in FIG. 1, and FIG. FIG. 1...electrode, la...first electrode, lb...second electrode,
2... Electrode support rack, 3... First nozzle, 3a...
2nd nozzle, 4, 7...Gas introduction pipe, 5...Collector, 6...Arc column, 8...Magnet, 9...Mizuka steel hearth, 10...Metal or alloy . Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] 1. In a discharge electrode device consisting of a discharge electrode and an electrode support frame for supporting the electrode and applying voltage, fine metal particles generated by arc discharge between the discharge electrode and a metal or alloy adhere to the discharge electrode. The present invention is characterized by having an arc column control means that reduces the concentration of metal fine particles around the discharge electrode by blowing and applying an air current or a magnetic field or both to the arc column as a means to prevent this. electrode device.