JP2002256499A - Electrode and electrode unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode and electrode unit, which can effectively protect a terminal part from corrosion caused by mist of an electrolytic solution, and consequently hardly generates a conduction failure. SOLUTION: The electrode 1 comprises an electrode body 20 and a power supply member 21. The electrode body 20 comprises a metallic base-material on the body side 11, and a discharge material 10d which is arranged in the state of being electrically conducted to the metallic base-material on the body side 11 and forms an electrode discharge face 3. The electrode discharge face 3 comprises being disposed as to be immersed in an electrolytic solution EL. Besides, the power supply member 21 comprises being disposed as to be exposed outside of the electrolytic solution EL, and being connected to the metallic base-material on the body side 11 in the state of being electrically conducted;. has a terminal part 2 on the power supply member, to which a cable side terminal part TR of a cable CB for power supply is detachably connected; and has a metallic base-material 12 on the power supply side, of which the component of the terminal part 2 on the power-supply member side comprises a Cu-based metal part. The surface of the Cu-based metal part 12 at a contact part with the cable terminal part, comprises being covered with a metal layer 10 for corrosion prevention, consisting of elastic low melting metals mainly including at least either Pb or Sn.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode used for electrochemical treatment such as electrolytic plating in a form immersed in an electrolytic solution, and to an electrode unit having the electrode and a current-carrying conductor.

[0002]

2. Description of the Related Art For example, an electrode using Pb as a discharge material portion is used in a line for continuously plating a steel strip with a metal such as Zn or Cr. Also, instead of Pb, a Pt group metal or its oxide (typically IrO
There is also an electrode using a discharge material part including ₂ ). These electrodes are provided with a discharge material portion that forms an electrode discharge surface on an iron-based electrode base material that is covered with a corrosion-resistant metal such as Ti or a resin as necessary, and is connected to the electrode base material. A structure is generally used in which power is supplied by a power supply conductor connected to an external power supply via a Cu power supply member. The current-carrying conductor is formed in a plate shape or a ring shape, for example, and is connected to the exposed terminal portion of the Cu power supply member by fastening it with a bolt nut or the like.

[0003]

In the above electrode, the material of the discharge material portion immersed in the electrolytic solution is substantially insoluble, which greatly contributes to the improvement of the electrode life. However, even when the terminal portion to which the power supply cable is connected is used by arranging it outside the electrolytic solution, since the terminal portion is arranged not far from the liquid surface of the electrolytic solution, it is easily exposed to the mist of the electrolytic solution, There is a problem that the power supply member made of Cu is deteriorated due to corrosion and is likely to cause poor current supply. Particularly when the electrolytic solution is heated, the amount of mist increases and the temperature rise causes the corrosion reaction to proceed more easily, so the terminal section has a longer life than the discharge material section. There is also a possibility that the improvement of the material of the discharge material portion or the like becomes meaningless. In addition, depending on the layout of the accompanying equipment around the plating tank, the terminal portion may have to be arranged immediately above the liquid level of the electrolytic solution, and the problem is more serious. As an improvement measure, for example, a method of wrapping a vinyl tape around a terminal portion to which a current-carrying conductor is connected, covering the terminal portion with a rubber cover to protect the terminal, or promoting exhaustion of mist by exhaust equipment is taken. However, none of them are effective enough.

[0004] It is an object of the present invention to provide an electrode and an electrode unit which can effectively protect a terminal portion from corrosion caused by electrolyte mist and, consequently, hardly cause poor conduction.

[0005]

Means for Solving the Problems and Action / Effect The electrode of the present invention for solving the above problems is provided in a state in which it is electrically connected to the main body side metal base and the main body side electrode base. And a discharge material portion forming an electrode discharge surface, and an electrode body portion disposed so that the electrode discharge surface is at least immersed in the electrolytic solution, and disposed in a form exposed outside the electrolytic solution. A power supply member formed with a power supply member side terminal portion to which an electrically conductive conductor is detachably connected while being electrically connected to the main body portion side metal base in a state of being electrically connected thereto; The member has a power supply member side metal base material in which a component of the power supply member side terminal portion is at least a Cu-based metal portion,
At least in the contact portion with the current-carrying conductor, the surface of the Cu-based metal portion has a structure covered with an anticorrosion metal layer made of a soft low-melting metal containing at least one of Pb and Sn as a main component. I do. Note that “Pb and Sn
At least one of the above as a main component "means that one or both of Pb and Sn is contained, and the total content thereof is 50% by mass or more.

According to the configuration of the electrode, since the portion forming the power supply member side terminal portion of the power supply member side metal base is made of a Cu-based metal portion, the conductivity is good, and the plating using the electrode is performed. Etc., the efficiency of the electrochemical treatment can be increased. On the other hand, since the Cu-based metal portion is covered with an anticorrosion metal layer made of a soft low-melting metal containing at least one of Pb and Sn as a main component at a contact portion with the current-carrying conductor, Compared with the case where the base metal part is used in a bare state, occurrence of conduction failure or the like due to corrosion is greatly reduced. In particular, a soft low-melting-point metal containing at least one of Pb and Sn as a main component is not only not easily corroded and consumed, but also is appropriately deformed even with a normal fastening force when a current-carrying conductor is crimped by fastening or the like. Since the state of adhesion to the current-carrying conductor is improved, and the improvement of the conduction state and the suppression of the penetration of corrosive mist are simultaneously achieved, this greatly contributes to the reduction of conduction failure.

Further, an electrode unit according to the present invention includes the above-described electrode and a current-carrying conductor detachably connected to the power-supplying-member-side terminal portion, and a contact surface of the current-carrying conductor with the power-supplying-member-side terminal portion is provided. At least one of Pb and Sn is used as a main component to form a corrosion-resistant metal layer made of a soft low-melting metal. In this configuration, the contact surface of the current-carrying conductor with the power-supplying-member-side terminal is also made of the above-mentioned soft low-melting-point metal, whereby corrosion of the current-carrying conductor is suppressed, and furthermore, the current-carrying conductor and the power-supplying member-side terminal The effect of improving the conduction state and suppressing the penetration of corrosive mist is further improved by improving the state of close contact with the portion, so that conduction failure due to corrosion can be further reduced.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1B, an electrode 1 according to one embodiment of the present invention has a plate-shaped electrode body 20. FIG. 1A shows an example of an apparatus for continuously plating a steel strip SS as a material to be treated using the electrode 1. The steel sheet strip SS is provided with a feed auxiliary roll 5
0a, is fed in the longitudinal direction between the electrodes 1 and 1 in the electrolytic solution tank T filled with the electrolytic solution EL such as a plating solution,
After being turned around by being rolled around the roll 50 inside the tank, it passes through another pair of electrodes 1, 1 and is discharged out of the tank via the auxiliary feeding roll 50a. In the electrolytic solution EL, the steel plate strip SS is continuously plated on both sides by two electrode pairs 1,1,1,1. Each electrode 1 is, as shown in FIG.
It is supported in a suspended state in the electrolytic solution tank T1, and is immersed in the electrolytic solution EL with one of its plate surfaces facing the steel plate strip SS, and faces the steel plate strip SS at a portion immersed in the electrolytic solution EL. The electrode discharge surface 3 is formed on the plate surface, and the other surface is covered with the polymer coating layer 4. The polymer coating layer 4 is made of an insulating polymer material having a property of shifting from a fluid state to a cured state, for example, a polymer material such as various plastics and rubbers, or a composite material based on them (for example, a fiber-reinforced plastic). Can be configured.

As shown in FIG. 2 (see also FIG. 5 and the like), the electrode main body 20 is provided in a state in which it is electrically connected to the main body side metal base 11 and the main body side electrode base 11. And a discharge material portion 10 d that forms the electrode discharge surface 3. Then, the electrode discharge surface 3 is arranged so as to be immersed at least in the electrolytic solution EL. On the other hand, the power supply member 21 is
L is disposed in a form exposed to the outside, and the main body side metal substrate 1
1 and is electrically connected thereto. Further, a power supply member side terminal portion 2 to which the conducting conductor CB is detachably connected is formed. The power supply member 21 includes the power supply member-side metal base 12 in which a component of the power supply member-side terminal portion 2 is at least a Cu-based metal portion. In this embodiment,
To improve conductivity, the entire power supply member side metal base 12 is made of Cu.
Although the base metal part is used, for example, only the constituent part of the power supply member side terminal part 2 may be a Cu base metal part, and the remaining part may be another material such as carbon steel. Then, as shown in FIG. 6A, at least the C
The surface of the u-based metal part 12 is covered with an anticorrosion metal layer 10 made of a soft low-melting metal mainly containing at least one of Pb and Sn.

The current-carrying conductor CB is for supplying a current from the power supply unit to the power supply member 21. In this embodiment, as shown in FIG. , Pb, and Sn as a main component, and is formed of a corrosion-resistant metal layer 52 made of a soft low-melting metal (the thickness is exaggerated in the figure).
Specifically, the current-carrying conductor CB covers the entire surface of the plate-shaped core material 51 with the anticorrosion metal layer 52. Note that, depending on the degree of the corrosive environment, only the contact surface of the core member 51 with the power supply member side terminal portion 2 may be covered with the anticorrosion metal layer 52.

In the present embodiment, the soft low-melting point metal is composed of inexpensive Pb simple metal. However, in consideration of, for example, the easiness of molten overlay described later, an appropriate amount of Sn is added. A low melting point solder alloy may be used.

As shown in FIG. 2, although the power supply member-side terminal portion 2 to which the current-carrying conductor CB is connected is arranged outside the electrolytic solution EL, it is located at a position not far from the level of the electrolytic solution EL. I do. For example, when the electrolytic solution EL is used by being heated by a heater (not shown) or the like, a large amount of mist is generated from the electrolytic solution EL, and the current-carrying conductor CB and the power supply member-side terminal 2
Attack the connection with the In particular, if any auxiliary equipment JS is disposed above the widthwise end of the plating tank T, the power supply member side terminal portion 2 is connected to the liquid level of the electrolyte EL in order to avoid interference with the auxiliary equipment JS. In some cases, it must be placed directly above, which makes it more susceptible to mist attacks. In FIG. 2, in order to avoid interference with the auxiliary equipment JS, the length of the arm-shaped power supply member 21 is changed to the configuration shown in FIG.
This is another embodiment of the electrode of the present invention except for the length of FIG. 2, which is the same as that of FIG. 2). It is located inside the direction edge.

However, according to the electrode 1, the Cu
The power supply member side metal base material 12 configured as a system metal part
At least a portion in contact with the conducting conductor CB is covered with the anticorrosion metal layer 10. Since the anticorrosion metal layer 10 made of a soft low-melting metal containing at least one of Pb and Sn as a main component is excellent in corrosion resistance and is soft, as shown in FIGS. Accordingly, when the current-carrying conductor CB is crimped, it is appropriately deformed even with a normal fastening force, and the state of close contact with the current-carrying conductor CB is improved. As a result, the conduction state is improved, and the penetration of corrosive mist to the contact interface between the current-carrying conductor CB and the anticorrosion metal tank 10 is suppressed, which greatly contributes to the reduction of conduction failure.

As shown in FIG. 6B, the contact surface of the current-carrying conductor CB with the power-supplying-member-side terminal portion 2 is also covered with the anticorrosion metal layer 52 made of the soft low-melting metal.
Corrosion of the current-carrying conductor CB is suppressed, and the effect of improving the conduction state and suppressing the penetration of corrosive mist is further improved by improving the state of adhesion between the current-carrying conductor CB and the power supply member side terminal portion 2.

Hereinafter, a more detailed configuration of the electrode 1 will be described. As shown in FIG. 6A, an insertion hole 15 through which a fastening member 17 for attaching the conducting conductor CB is inserted is formed in the power supply member side terminal portion 2. The current-carrying conductor CB is held between the seating surface of the head 17a of the fastening member 17 inserted into the insertion hole 15 and the peripheral edge of the opening of the insertion hole 15. Further, it becomes a direct contact portion between the power supply member side terminal portion 2 and the conducting conductor CB.
The periphery of the opening of the insertion hole 15 is covered with the anticorrosion metal layer 10. Corrosion-resistant metal layer 10 covering the periphery of the opening of insertion hole 15
Is clamped between the head 17a of the fastening member 17 and the Cu-based metal portion 12 serving as a base by fastening, and the effect of improving the adhesion as shown in FIG. 8 is further enhanced. In the present embodiment, the fastening member 17 is a bolt having a head portion 17a, and after passing this through a center hole of the ring-shaped current-carrying conductor CB, a bolt leg portion protruding from an opening opposite to the insertion hole 15 is provided. The above-described fastening state is formed by screwing the nut 18 to the tip of the nut.

The inner peripheral surface of the insertion hole 15 as well as the periphery of the opening is covered with the anticorrosion metal layer 10. Accordingly, the exposed portion of the underlying Cu-based metal portion 12 hardly occurs near the insertion hole 15 involved in the connection of the current-carrying conductor CB. It becomes difficult.

The anticorrosion metal layer 10 can be formed, for example, as a built-up portion of the soft low melting point metal. The material of the soft low-melting metal is heated and melted, and the surface of the Cu-based metal part 12 is melt-faded, whereby the corrosion-resistant metal layer 10 having a relatively large thickness and excellent corrosion resistance can be easily formed. In this case, it is desirable that the average thickness t of the built-up portion to be formed is about 0.5 to 4 mm. If the average thickness t is less than 0.5 mm,
It becomes difficult to form a built-up portion having a uniform thickness, and Cu
In some cases, the surface of the system metal part 12 cannot be uniformly coated, and the anticorrosion effect may be insufficient. On the other hand, formation of the overlaid portion having a thickness of 4 mm or more cannot expect a further dramatic improvement in the anticorrosion effect, and involves a wasteful increase in the amount of metal used.

In FIG. 6, the cladding portion 10 of the soft low-melting metal is provided with an inner coating portion 1 covering the inner peripheral surface of the insertion hole 15.
0i. Such an inner surface covering portion 10i can be easily and reliably formed by the method shown in FIG. First, as shown in FIG.
A through hole 12a is formed in the system metal part 12, and as shown in FIG. 7B, the inside of the through hole 12a is filled with a soft low melting point metal to form a metal filling part 10f. Next, FIG.
As shown in (c), by removing the metal-filled portion 10f in such a manner as to leave a portion intended for the inner surface covering portion 10i,
An insertion hole 15 whose inner peripheral surface is the inner surface covering portion 10i is obtained.

On the other hand, as shown in FIG. 10, the anticorrosion metal layer can be formed to include a soft low-melting-point metal plating layer 80. This method has an advantage that it is difficult to form a thick film as in the above-mentioned built-up portion, but it is easier to form. The plating layer 80 may be formed by electrolytic plating of a solder alloy, but a solder alloy powder prepared in a paste form together with a flux is applied to the surface of the anticorrosion metal layer and reflowed at an appropriate temperature. If a kind of hot-dip plating method is adopted, the plating layer 80 can be formed more reliably and more easily. FIG. 10A shows an example in which not only the surface of the Cu-based metal part 12 but also the inner peripheral surface of the insertion hole 15 is covered with the plating layer 80. The plating layer covering the inner peripheral surface may be omitted, and the Cu-based metal portion 12 may be exposed.
On the other hand, when it is difficult to uniformly coat the inner peripheral surface,
The surface of the Cu-based metal part 12 other than the inner peripheral surface is plated
On the other hand, it is also possible to cover the inner peripheral surface with a built-up portion formed by the method shown in FIG. In this case, the order of forming the inner peripheral surface cladding portion and the plating layer 80 is not particularly limited. Note that the average thickness of the plating layer 80 is preferably about 1 to 700 μm in consideration of ensuring corrosion resistance and plating time.

Next, in the electrode 1 of this embodiment, as shown in FIG. 4, the power supply member 21 is formed in a horizontally long plate shape.
The power supply member side terminal portion 2 is formed at one end thereof. Then, as shown in FIG. 6, the entire surface of the power supply member side terminal portion 2 is covered with the anticorrosion metal layer 10. Power supply member 2
1 is made horizontally long and the power supply member side terminal portion 2 is formed at the end thereof, so that the power supply cable CB can be easily attached and detached.
Also, by covering the entire surface of the power supply member side terminal portion 2 with the anticorrosion metal layer 10, the exposed portion of the Cu-based metal portion 12 is eliminated,
The occurrence of conduction failure can be further reduced.

As already described with reference to FIG. 1, the electrode 1 of the present embodiment has the polymer material coating layer 4. The polymer material coating layer 4 covers the power supply member 21 so as to partially overlap the anticorrosion metal layer 10 on the Cu-based metal portion 12 while exposing the power supply member side terminal portion 2 of the power supply member 21. It is also considered. By forming an overlapping portion between the anticorrosion metal layer 10 and the polymer material coating layer 4, the polymer material coating layer 4 and the base material are separated from the boundary between the power supply member side terminal portion 2 and the portion covered by the polymer material coating layer 4. Even if some corrosive mist or the like permeates between the base material and the base material, since the underlying portion is the anticorrosive metal layer 10, Cu
Corrosion of the system metal part 12 can be prevented.

As shown in FIG. 4, in the present embodiment, the electrode base metal part 11 and the electrode base metal base 11 are separated.
The entirety of the power supply member-side metal base material 12 connected to the power supply member-side metal base material 12 is a soft low melting point metal layer 10 (here,
Pb single metal). The exposed region of the soft low-melting metal layer 10 is formed in each of the formation region of the power supply member side terminal portion 2 of the power supply member side metal base material 11 and the formation region of the electrode discharge surface 3 of the electrode body portion side metal base material 11. The outer surface of the soft low-melting metal layer 10 is covered with a polymer coating layer 4 as will occur. Then, the exposed portion of the soft low-melting metal layer 10 in the formation region of the electrode discharge surface becomes the discharge material portion 10d, and the exposed portion of the soft low-melting metal layer 10 in the formation region of the power supply member-side terminal portion 2 has the corrosion prevention already described. Metal layer 1
It becomes 0. According to this configuration, when forming the discharge material portion 10d, the entirety of the electrode body portion side metal base material 11 and the power supply member side metal base material 12 may be wrapped together with the soft low melting point metal layer. Since the formation of the anticorrosion metal layer 10 of the member-side terminal portion 2 can be performed collectively, the entire electrode can be configured at low cost.

More specifically, the base end of the Cu-made horizontally long power supply member-side metal base material 12 is connected to the one end of the electrode main body-side metal base material 11 made of carbon steel plate by a carbon steel connection member. It is connected via a plate 13. FIG. 5B is an enlarged cross-sectional view of the coupling portion, in which a bolt 33 inserted into a through hole 12 b formed in the base end of the power supply member side metal base 12.
And a bolt 34 inserted into a through hole 11b formed at the edge of the power supply member-side metal base material 12, into the screw holes 31 and 32 of the connection plate 13 stacked on the back side, respectively, thereby forming the electrode body. The unit-side metal base 11 and the power supply member-side metal base 12 are coupled to each other. The power supply member-side metal base 12 may be an integrated L-shaped copper plate including a portion corresponding to the connection plate 13.

As shown in FIG. 4, the periphery of the electrode discharge surface 3 is covered with a polymer coating layer 4 in a frame shape. Then, as shown in FIG. 5 (a), the peripheral edge of the anticorrosion metal layer 10 on the side where the electrode discharge surface 3 is formed is cut out in the thickness direction to form a step 10a. A groove 5 (a biting recess) is formed along the periphery of the groove 3 by groove cutting or the like. The groove 5 has a tapered surface 5a on the inner surface located farther from the outer edge of the electrode discharge surface 3 so that the groove width becomes wider as approaching the groove bottom. On the polymer coating layer 4 side, a ridge 6 (biting ridge) having a cross-sectional shape corresponding to the groove 5 is formed so as to bite into the groove 5. By forming the groove portion 5 and the ridge portion 6 in such a cross-sectional shape, the ridge portion 6 is prevented or prevented from falling out of the groove portion 5, and the polymer coating layer 4 is formed on the electrode body 2.
A state of being firmly bound to zero can be maintained for a long period of time.

As shown in FIG. 11, a concave portion 2f is formed at a position corresponding to the electrode discharge surface 3 of the power supply member-side metal base material 12, and is filled with a soft low-melting point metal.
The soft low melting point metal layer 10 covering only a part of the surface of the power supply member side metal base 12 may be formed.

As shown in FIG. 9, the power supply member-side metal base 12 can be configured such that only a necessary part of the surface is covered with the soft low-melting metal layer 10. For example, in the configuration of FIG.
Only one end side of 2 is covered with the soft low-melting point metal layer 10 (formed as the above-mentioned built-up portion) including the inner surface of the insertion hole 15. In the present embodiment, the surface layer of the power supply member-side metal base 12 is removed with a predetermined thickness, and the cutout 12
The notch 12r is filled with a soft low-melting-point metal overlay 10. In addition, the polymer coating layer 4 has an overlapping portion 60 m with a certain length on the base end side of the soft low melting point metal layer 10.
Has occurred. On the other hand, in the configuration of FIG. 9B, a soft low-melting-point metal overlay 10 covering only the inner peripheral surface of the insertion hole 15 of the power supply member-side metal base 12 and the peripheral portions of both openings is formed. It is an example.

The structure of the power-supplying-member-side terminal, which is a feature of the present invention, is not limited to the electrode in which the discharge material portion is composed of a single Pb metal as described above. The present invention can also be applied to an electrode using a discharge material portion containing (typically, IrO ₂ ). Also in this case, the power supply member-side terminal portion can be configured in exactly the same manner as that shown in FIGS. 6 and 9, for example.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing an example of disposing an electrode of the present invention in an electrolytic solution tank.

FIG. 2 is a front view showing an example of the electrode of the present invention.

FIG. 3 is a front view showing a modification of the electrode of FIG. 2 in which the power supply member is elongated.

FIG. 4 is a front view showing the inside of a polymer coating layer of the electrode of FIG. 2 in a see-through form.

5 is a sectional view taken along line AA and a sectional view taken along line BB of FIG. 4;

FIG. 6 is a cross-sectional view of the same CC and a cross-sectional view showing an example of an internal structure of a current-carrying conductor.

FIG. 7 is a process explanatory view showing an example of a method of forming a power supply member-side terminal portion shown in a cross-sectional view taken along the line CC of FIG. 4;

FIG. 8 is an explanatory diagram of an action of a soft low-melting metal layer in the electrode of the present invention.

FIG. 9 is a cross-sectional view showing some modified examples of a formation form of a built-up portion forming a soft low-melting metal layer of a power supply member side terminal portion.

FIG. 10 is a cross-sectional view showing some examples in which a soft low-melting metal layer of a power supply member side terminal portion is configured as a plating layer.

FIG. 11 is a sectional view showing an example in which only a region corresponding to an electrode discharge surface of an electrode body side metal substrate is selectively covered with a soft low melting point metal layer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrode 2 Power supply member side terminal part 3 Electrode discharge surface 4 Polymer coating layer 10 Soft low melting point metal layer (facing part) 11 Electrode main body side metal base material 12 Power supply member side metal base material 15 Insertion hole 17 Fastening member 17a Head Part 20 electrode body part 21 power supply part 80 plating layer (soft low melting point metal layer) CB conducting conductor

Claims (9)

[Claims] 1. A main body-side metal base material, and a discharge material portion provided in an electrically conductive state with the main body-side electrode base material and forming an electrode discharge surface, wherein the electrode discharge surface is An electrode body portion arranged at least so as to be immersed in the electrolytic solution; and an electrode body portion arranged so as to be exposed outside the electrolytic solution and electrically connected to the body-side metal base. And a power supply member formed with a power supply member side terminal portion to which a current-carrying conductor is detachably connected, wherein the power supply member has at least a Cu-based metal A power supply member-side metal base material, and at least in a contact portion with the current-carrying conductor, the surface of the Cu-based metal portion is made of a soft low-melting metal containing at least one of Pb and Sn as a main component. Has a structure covered with an anticorrosion metal layer Electrode, wherein Rukoto. 2. The power supply member side terminal portion is formed with an insertion hole through which a fastening member for attaching the current-carrying conductor is inserted, and a head seat surface of the fastening member inserted through the insertion hole. And the current-carrying conductor is held between the opening peripheral portion of the insertion hole and the opening conductor,
2. The electrode according to claim 1, wherein the periphery of the opening of the insertion hole is covered with at least the anticorrosion metal layer. 3. 3. The electrode according to claim 2, wherein an inner peripheral surface of the insertion hole is covered with the anticorrosion metal layer together with the peripheral portion of the opening. 4. The anticorrosion metal layer has an average thickness of 0.5 to 0.5.
The electrode according to any one of claims 1 to 3, further comprising a built-up portion of the soft low-melting metal of 4 mm. 5. The electrode according to claim 1, wherein the anticorrosion metal layer includes a plating layer of the soft low melting point metal. 6. The power supply member is formed in a horizontally long plate shape, the power supply member side terminal portion is formed at one end thereof, and the entire surface of the power supply member side terminal portion is covered with the anticorrosion metal layer. The electrode according to any one of claims 1 to 5, wherein: 7. A polymer material that covers the power supply member so as to partially overlap the anticorrosion metal layer on the Cu-based metal portion while exposing the power supply member-side terminal portion of the power supply member. 7. The electrode according to claim 6, which has a polymer coating layer as a main component. 8. A soft low-melting metal made of the soft low-melting metal as a whole of the electrode main body-side metal base and the power supply member-side metal base connected to the electrode main body-side metal base. The soft low melting point is formed in a region where the power supply member-side terminal portion of the power supply member-side metal substrate and a region where the electrode discharge surface of the electrode body portion-side metal substrate is formed. The outer surface of the soft low-melting metal layer is covered with the polymer coating layer so that an exposed region of the metal layer is formed, and the exposed portion of the soft low-melting metal layer in a region where the electrode discharge surface is formed is 8. The electrode according to claim 7, wherein the electrode is a discharge material portion, and an exposed portion of the soft low-melting metal layer in a region where the power supply member side terminal portion is formed is the anticorrosion metal layer. 9. The power supply member side of the power supply member, comprising: the electrode according to claim 1; and a power supply conductor detachably connected to the power supply member side terminal portion. An electrode unit characterized in that at least a contact surface with a terminal portion is constituted by an anticorrosion metal layer made of a soft low-melting metal mainly containing at least one of Pb and Sn.