JPH09248617A - Apparatus for locally treating vacuum arc descaling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently execute the descaling only to a part of the surface of a large scaled member in a short time by arranging a cupped vacuum vessel imcorporating an electrode and having a sealing material for holding the stickiness to the member to be treated at the foot part. SOLUTION: The cupped vessel 2 is formed so as to be possible to stick to the member 1 to be treated through the vacuum sealing material 7. The cupped vessel 2 is connected with an evacuating device through an evacuating part 3. After sticking the cupped vessel 2 to the member 1 to be treated, the pressure in the vessel is reduced with the evacuating device and then, the cupped vessel 2 is intensely held pressed to the member 1 to be treated to automatically strengthen the sealing effect, and the vacuum degree in the cupped vessel is made to high and held.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface treatment field for removing an oxide film and dirt on a surface of a metal member by causing a DC arc discharge between an anode and a cathode in a vacuum, The present invention relates to a vacuum arc descaling local processing device.

[0002]

In vacuum arc descaling, usually 1
Arc discharge is performed in an atmosphere of 0 ⁴ Pa to 1 Pa.
It is called vacuum arc descaling, but it is not a technology in a strict sense in a vacuum state, but a scale removal technology using an arc created in a reduced pressure atmosphere. In the present invention, an arc formed in a reduced pressure atmosphere is also called a vacuum arc according to the customary practice. Including scale removal or thin oxide film removal is called descaling below. Since the vacuum arc descaling process produces fine irregularities on the surface, it may be used as a method for roughening the surface. The scale removal or surface roughening processing using a vacuum arc is collectively referred to as vacuum arc descaling in the present invention. In the vacuum arc descaling, a processing target member for which scale is to be removed is connected to a negative polarity of a power source to act as a cathode and generate an arc between a separately installed anode. The oxide film on the surface of the cathode is removed by the action of the arc cathode spots formed on the surface of the object to be treated which becomes the cathode.

Conventionally, in order to carry out this kind of vacuum arc descaling, a vacuum container for accommodating all the members to be subjected to the descaling is provided as shown in, for example, Japanese Unexamined Patent Publication No. 4-110084. A vacuum arc is generated between a member to be used as a cathode and an anode separately installed in a vacuum container to remove the scale on the entire surface of the member. In the case of removing the scale of only a specific part of the surface of the member, the masking process has been performed leaving only the surface to be treated.

[0004]

In the conventional vacuum arc descaling, a large vacuum container is required for a large member because the whole member is put in a vacuum container and subjected to a vacuum arc treatment. However, there is a problem that it takes a long time to reduce the pressure of a large container and the operating cost becomes large. In many cases, even if the member itself is long, only a part of the surface that requires descaling is sufficient. In this case, excessive equipment is used and wasteful operation is performed.

Further, masking for treating only a part is a troublesome work, and gas is released from the masking material, which sometimes makes it difficult to create a vacuum atmosphere. Therefore, in many cases, descaling processing is performed on unnecessary surfaces without masking. In this case, since excess energy is input to the member, not only is energy wasted, but the temperature of the entire member excessively rises, causing the member shape to deform,
There is also the problem that the characteristics will change.

In order to solve these problems, an object of the present invention is to provide an apparatus capable of locally forming a vacuum atmosphere and locally performing a vacuum arc treatment.

[0007]

The present invention is an invention which solves the above-mentioned problems by creating a local vacuum and subjecting only a local portion to a vacuum arc treatment. A vacuum consisting of an electrode, a vacuum container, a DC power supply and an exhaust device. In the arc descaling device, the vacuum arc descaling device is characterized in that the vacuum container is a cup-shaped vacuum container having an electrode incorporated therein and a sealing material at the hem for providing adhesiveness with a member to be processed. Is.

The concept of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the basic principle of the present invention. In order to create a local vacuum atmosphere, the cup-shaped container 2 can be brought into close contact with the member 1 to be processed via the vacuum sealing material 7. The cup-shaped container 2 is connected to a vacuum exhaust device via a vacuum exhaust port 3. When the cup-shaped container is brought into close contact with the member to be treated and then depressurized into the container by the vacuum exhaust device, the cup-shaped container is strongly pressed against the member to be treated due to the pressure difference between the outside of the container and the sealing effect is automatically increased. The degree of internal vacuum is increased and maintained. An electrode 4 is installed inside the cup-shaped container.

The electrode installed in the cup-shaped container according to the present invention does not necessarily have to be a component independent of the cup-shaped container as shown in FIG. 1, and for example, a part of the cup-shaped container as shown in FIG. Including the case of In any case, it is desirable that the electrodes and the cup-shaped container have a water cooling structure. Further, the electrode part must be electrically insulated from other container parts. Reference numerals 5 and 6 in FIG. 1 denote cooling water supply / drain ports.

The electrode 4 and the member 1 are connected to a DC power source for arc generation. For starting the arc, various methods have been established as known techniques such as a method of applying a high frequency high voltage, a method of instantaneously contacting an anode with a cathode, and a method of using an auxiliary electrode, and any method may be adopted. or,
Similarly, the arc power supply, the electrode and the arc power supply, the arc start circuit, and the method of joining the electrodes with the electric equipment are not the basis of the present invention, and thus detailed description thereof is omitted.

The component 8 shown in FIG. 2 is a detachable container which is an auxiliary container for coping with the case where the shape of the member or the processing area is changed, and has a sealing portion adapted to the processing shape of the member to be processed. The side in contact with the container is characterized by further including an auxiliary container having a surface conforming to the cup shape.

Reference numeral 9 in FIG. 3 denotes an electric circuit switching mechanism for changing the polarity of the electrodes, which is arranged between the DC power source 10 and the members and the electrodes. Since only the principle of the invention is described, the whole or a part of the vacuum exhaust equipment, the arc power supply circuit, the cooling water supply / drainage equipment and the like are omitted in the drawing.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The operation of the means of the present invention for solving the above problems will be described with reference to the drawings. In order to locally create a vacuum atmosphere in a region that requires descaling on the surface of a member (for example, a steel material) 1 to be vacuum-arced,
There is a cup-shaped container 2. The cup-shaped container 2 is provided with a sealing material 7 such as an O-ring capable of vacuum sealing on the surface in contact with the member 1. The cup-shaped container 2 is connected to a vacuum exhaust device through a vacuum exhaust port 3. An electrode 4 for generating a vacuum arc is installed in a cup-shaped container 2 that enables a local vacuum. Container 2 is electrode 4
Also, it is electrically insulated from the member 1 to be descaled. The vacuum arc is connected to a DC arc power supply so as to occur between the member 1 and the electrode 4. In order to perform surface descaling of member 1, member 1 has a negative polarity,
The electrode 4 is connected so as to have a positive polarity. It is desirable that the cup-shaped container 2 and the electrode 4 have a water-cooled structure because the temperature becomes high due to the generation of a vacuum arc. Reference numerals 5 and 6 in FIG. 1 denote water supply / drainage ports for cooling water to the cup-shaped container and the electrode, respectively.

Since the area shape to be locally processed is not constant, it is possible to deal with the change of the area shape by shielding an extra area in the cup-shaped container as long as it can be covered by the cup-shaped container. it can. When processing an area beyond the range that can be covered by the cup-shaped container, as shown in FIG. 2, a hem portion (hem jig) 8 of the cup-shaped container is made a detachable mechanism and the hem portion 8 is replaced. Corresponds to changes in shape. It is necessary to be able to maintain a vacuum atmosphere after the attachment / detachment and replacement, but such a sealing mechanism is a known technique, and therefore its explanation is omitted.

FIG. 3 shows a local vacuum arc descaling processor having a polarity switching mechanism. As described above, originally, the vacuum arc descaling is performed by using the processed material as the cathode and the separately installed electrode as the anode. There are various purposes for switching the polarity. One of them is electrode cleaning. With vacuum arc descaling,
When the electrode used as the anode becomes dirty and the vacuum arc descaling action is no longer performed normally, the polarity switching mechanism 9 is used to reverse the polarity, and the electrode that has conventionally operated as the anode becomes the cathode. The surface of the electrode is cleaned by the cleaning action of the cathode spot.
If the polarity switching mechanism 9 is used again to reverse the polarity after performing the cleaning process, the original descaling process can be performed. Since the polarity switching mechanism is emphasized in FIG. 3, the originally required water cooling structure and vacuum exhaust structure are not shown. Reference numeral 10 indicates a DC power supply.

In the device as shown in FIG. 3, the second purpose of switching the polarities is to switch the polarities.
It is to perform vacuum arc vapor deposition. After the surface of the member 1 is cleaned by the descaling process, when the polarity is switched without breaking the vacuum atmosphere, the conventional anode 4 operates as a cathode, and the electrode 4 is formed from the surface of the electrode 4. The existing elements evaporate. Because the atmosphere is a vacuum,
The evaporation element is deposited on the surface of the member 1 to form a vapor deposition film. Since the cleaning treatment of the member surface and the vacuum vapor deposition film formation can be carried out in the same apparatus without breaking the vacuum, the economical effect is large and the film performance is improved.

1, FIG. 2 and FIG. 3 are all characterized in that a separate electrode is installed in the vacuum container to perform the vacuum arc descaling process, but as shown in FIG. A part of the vacuum container 2 can be used as an electrode. FIG. 4 is a diagram when the ceiling portion 4'of the cup-shaped container is used as an electrode. Also in this case, the electrodes 4'are 5 and 6
Cooling water is supplied and drained from the port indicated by. Electrode 4 '
Is fixed to the vacuum container 2 ′ via an insulating material 11. If the electrode 4'is directly connected to the positive electrode of the power source, the electrode 4 as shown in FIGS. 1 to 3 becomes unnecessary.

[0018]

【Example】

(Example 1) The conventional vacuum arc descaling method was used to remove the scale in a circle area of 100 mm in diameter at the center of the surface of a hot rolled steel material covered with a scale of 0.5 mm x 1 m and a thickness of 8 mm. Table 1 shows a comparison between the work time and the required power when the device of the present invention is used. As a conventional vacuum arc method, after masking with a glass tape leaving a circle with a diameter of 50 mm in the center of the hot rolled plate, put the hot rolled plate in a large vacuum container and connect the electric circuit so that it becomes a cathode, and vacuum. Descaling was performed by generating an arc with an anode separately installed in the container. For reference, the results of the conventional method when descaling the entire surface without masking treatment are also shown. As processing according to the present invention, local descaling was performed using a cup-shaped cylindrical container having an inner diameter of 50 mm as shown in FIG. The masking work time is the time required to cover the area where descaling is not necessary with the glass tape. Since there is no such work in the full-scale descaling in the conventional method and the local descaling in the present invention, it is 0.
It is. Exhaust time is 50Pa to start vacuum arc
Is the time it takes to exhaust.

Even if the hot-rolled steel sheet having a scale surface with minute irregularities is a member to be treated, a sufficient decompressed atmosphere can be achieved in the cup-shaped container using the O-ring seal as a sealing material. It could be scaled.
The descaling required time and descaling energy consumption are the time from vacuum arc ignition to the end of descaling and the electric power input during this period. Regarding the scale removal condition, the surface texture after the descaling was visually observed, and if no scale residue was found, it was judged as good. The steel material temperature is the temperature at the center of the back surface of the material immediately after the end of descaling. In either case, the arc current is 100
A was performed at a constant rate. When the conventional method is used for full-scale descaling without masking, the temperature of the steel material rises and the central part becomes red hot, so the descaling work is stopped at 480 seconds after the ignition of the arc.

[0020]

[Table 1]

(Embodiment 2) An embodiment in which the surface of the substrate is cleaned and the Cu vapor deposition film is formed by the method shown in FIG. Using a stainless steel plate as a base material, a cylinder made of copper,
It was used as an electrode facing stainless steel. First, after exhausting the interior of the local vacuum container to 2 Pa, vacuum arc descaling with a stainless steel plate as the cathode and copper as the anode was performed under the conditions shown in Table 2, then the vacuum arc was extinguished, and the stainless steel material was switched by the polarity switching mechanism. Was used as an anode and a copper electrode was used as a cathode, and a vacuum arc was generated under the vapor deposition conditions shown in Table 3. During this time, the vacuum state is maintained without breaking.
It was confirmed that a cathode spot with high energy density was formed on the copper surface, copper was evaporated, and the surface of stainless steel was replaced with the hue of metallic copper to form a copper film. Even when this stainless steel sample was taken out and subjected to right-angle bending, peeling of the copper film was not observed, and it was confirmed that a copper film having high adhesion was formed on the stainless steel material.

[0022]

[Table 2]

[Table 3]

(Embodiment 3) Two kinds of hem jigs indicated by reference numeral 8 in FIG. 2 were prepared. As the cup-shaped container indicated by reference numeral 2, a water-cooled container having an inner diameter of 50 mm is used. The hem jig spreads the hem, and the cross section of the expanded end is a circle with an inner diameter of 60 mm and one with a 50 mm inner diameter and a square cross section with a side of 60 mm. Was attached to a water-cooled cup-shaped container having an inner diameter of 50 mm, and vacuum arc descaling was performed. In each case, as a result of observing the descaled shape of the surface of the member 1, depending on the shape of the end of the hem jig, a 60 mm diameter end has a descaled surface of 61 mm in diameter, and a 60 mm square end. With the hem jig, a square descale surface having a side of 61 mm was obtained. It was confirmed that the area corresponding to the shape of the hem can be easily descaled by replacing the hem.

(Embodiment 4) Based on the principle structure shown in FIG. 4, a water-cooled copper cylinder 2'having an inner diameter of 50 mm and an O-ring seal portion at the hem, an insulating ring 11 made of alumina, and an anode ceiling 4 made of water-cooled copper 4 are used. , A water-cooled copper anode 4'is used as an anode, the stainless hot-rolled steel material 1 with scale is used as a cathode, and a part of the surface of the stainless hot-rolled material is used as a depressurized atmosphere with a pressure of 20 Pa to produce a vacuum. Arc descaling processing was performed. After maintaining the arc for 10 seconds under the condition of an arc current of 100 A, the arc was stopped and the surface descaling state was observed. It was confirmed that the surface of the stainless steel material was satisfactorily descaled.

[0025]

As described above, according to the present invention, it is possible to perform a local descaling process on a large-sized member, and a large-sized vacuum container and large-sized exhaust equipment are unnecessary. Descaling of only the necessary local parts is possible without masking or with extremely simple masking, shortening the exhaust time to create a vacuum atmosphere,
It is possible to shorten the descaling processing time and significantly reduce the power required for the descaling processing. Local surface vapor deposition coating work enables surface pretreatment and vacuum vapor deposition with the same equipment, and enables formation of a film with high adhesion.

[Brief description of drawings]

FIG. 1 is a principle diagram of a vacuum arc descaling local processing apparatus of the present invention.

FIG. 2 is a principle diagram of a vacuum arc descaling local processing apparatus of the present invention having a skirt jig.

FIG. 3 is a principle diagram of a vacuum arc descaling local processing apparatus of the present invention having a polarity switching mechanism.

FIG. 4 is a principle diagram of a vacuum arc descaling local processing apparatus of the present invention in which a part of a vacuum container is used as an electrode.

[Explanation of symbols]

 1 member (normal cathode) 2 vacuum container 2'vacuum container body part 3 vacuum exhaust port 4 electrode (normal anode) 4'ceiling electrode (normal anode) 5 water supply port 6 drainage port 7 sealing material 8 hem (hem jig) 9 Polarity switching mechanism 10 DC power supply 11 Insulation material

Front page continuation (72) Inventor Motoki Tamura 1618 Ida, Nakahara-ku, Kawasaki-shi, Kanagawa Nippon Steel Corporation Technology Development Division

Claims (3)

[Claims] 1. A vacuum arc descaling device comprising an electrode, a vacuum container, a DC power supply, and an exhaust device, wherein the vacuum container incorporates an electrode and has a sealing material at the hem for providing adhesion to a member to be processed. Vacuum arc descaling device, which is a cup-shaped vacuum container. 2. The auxiliary container having a seal portion matching the processed shape of the member to be processed, and the side contacting the cup-shaped container further having an auxiliary container having a surface matched to the cup shape. The vacuum arc descaling device described. 3. The vacuum arc descaling device according to claim 1, further comprising an electrode polarity switching device on a circuit connecting the arc DC power supply and the vacuum arc electrode.