JPH1121699A - Apparatus for forming surface oxide film on long workpieces such as nuclear fuel cladding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for producing a wear-resistant surface oxide film by electrolytically treating a long material to be treated such as a nuclear fuel cladding tube, and immersing the entire material to be treated in an electrolytic solution. Without the need to perform the electrolysis while running and passing through a small amount of electrolyte, the equipment can be significantly reduced in size. SOLUTION: An electrolytic solution supply tank 4 to which an electrolytic solution E is supplied by an inlet side wall 3a and an outlet side wall 3b of an electrically insulating outer tank body 1 and a cathode plate 2 connected to a cathode side N of a DC power supply unit 6.
Is installed internally. The long material to be treated M, which is electrically connected to the anode side P of the DC power supply unit 6, is supplied from the inlet side sliding contact 4a of the inlet side wall 3a to the outlet side sliding contact 4b of the outlet side wall 3b through the electrolytic solution E. It can be fitted in the sealed state. By operating the transfer device 5 at a predetermined traveling speed in the direction of the arrow A, the surface oxide film is continuously generated over the entire length by the operation of the transfer device unit 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of immersing a long material to be treated made of various metals, for example, a nuclear fuel cladding tube made of a zirconium alloy in an electrolytic solution of an electrolytic cell, and connecting a cathode side of a DC power supply to the electrolytic solution. A current is passed by connecting the cathode to the cathode plate in the electrolytic solution and connecting the anode side to the above-mentioned long workpiece, thereby providing a surface oxidation having wear resistance and high corrosion resistance over the entire length of the long workpiece. The present invention relates to a miniaturized device capable of producing a film.

[0002]

2. Description of the Related Art As is well known, a material made of a zirconium alloy such as Zircaloy-2 or Zircaloy-4 has been adopted for forming a nuclear fuel cladding tube in a nuclear fuel element used in a light water reactor. All of the above-mentioned zirconium alloys are materials having excellent corrosion resistance. However, when exposed to high-temperature and high-pressure steam for a long time inside the nuclear reactor, the zirconium alloy has a spot-like undesirable oxidation called nodular corrosion. An object will be generated.

[0003] The above-mentioned oxide, which is nodular corrosion, damages the outer surface of the nuclear fuel cladding tube due to unintentional contact with other members, such as spacers and springs, during assembly of the fuel assembly. It is known to occur on the scar. Therefore, in order to suppress the occurrence of such nodular corrosion, it has been already practiced to form a highly corrosion-resistant surface oxide film on the outer surface of the nuclear fuel cladding tube. And, in the case of the nuclear fuel cladding tube, since it is relatively soft itself, wear marks due to the above-described assembling work are apt to occur, and therefore considerable care is required in handling the nuclear fuel cladding tube, This kind of work is difficult. Therefore, on the outer surface of the nuclear fuel cladding,
As described above, there is a demand for the generation of a surface oxide which is excellent not only in corrosion resistance but also in wear resistance.

Therefore, as a means for generating a surface oxide film as described above, a long material to be treated such as a nuclear fuel cladding tube is subjected to an autoclave treatment, or a current is supplied to an electrolyte using the nuclear fuel cladding tube as an anode. It is known that a surface oxide is formed by flowing anodizing treatment. In order to implement the latter generation means, a considerably long nuclear fuel cladding tube is placed in a large electrolytic cell in which this can be stored. The long material to be treated is immersed in an electrolytic solution to simultaneously treat the entire surface of the material to be treated. As a result, a very large surface treatment film generating apparatus is installed.

[0005]

In the case of the above-described apparatus for forming a surface oxide film according to the prior art, a long material to be treated must be immersed in an electrolytic solution to complete the process. If a surface oxide film with high corrosion resistance and excellent wear resistance is to be applied to the surface, equipment including a considerably large-sized electrolytic cell is required, and thus not only requires a large facility area but also the equipment can be used. This implies serious deficiencies, such as forced investment.

The present invention is intended to solve the above-mentioned problems of the prior art. According to the first aspect of the present invention, it is possible to supply an electrolytic solution having a relatively small size with respect to the length of a long material to be treated such as a nuclear fuel cladding tube. Install a tank. Then, in the electrolyte stored therein, the long material to be treated is immersed and passed by the operation of the transfer device in the liquid-sealed state, and in the process of the passing, continuously long. A surface oxide film is generated on a material to be processed, and thus, a very small-sized facility can be used to generate a surface oxide film, thereby solving the problem of the facility site and capital investment.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, the electrolytic solution is circulated between the electrolytic solution outlet and the electrolytic solution inlet of the electrolytic solution supply tank, and An electrolytic solution circulation channel for removing bubbles due to oxygen or hydrogen is provided, thereby making it possible to realize good surface oxide generation.

Further, in the case of a third aspect, in the first or the second aspect, the anode having an appropriate thickness and length is used for connecting the long workpiece to the anode side of the DC power supply unit. By using a connector, the connection work can be performed easily and quickly, and the running of the long material to be processed in the electrolytic solution can be smoothly performed, and over the entire length of the long material, The entire surface oxide film can be formed without losing its formation.

According to a fourth aspect of the present invention, a cleaning water tank is provided adjacent to the structure of the first aspect, and an inlet-side fitting port and an outlet-side fitting port are opened in the washing water tank. The material to be treated, which has passed through the electrolytic solution, is supplied to the washing water tank as it is, washed with distilled water or the like, and then discharged, so that a long surface oxide film is formed. It enables efficient production of materials to be treated.

[0010]

In order to achieve the above object, according to the present invention, there is provided an electrically insulating outer tank body and an electrolytic solution supply formed by the electrically insulating outer tank body and the cathode body. The tank, between the electrolyte outlet and the electrolyte inlet of the electrolyte supply tank, by circulating the electrolyte, the electrolyte circulation flow path connected in order to remove bubbles in the electrolyte,
An inlet-side sliding contact and an outlet-side sliding contact with which a long material to be processed is fitted in a liquid-sealed state on the inlet side wall and the outlet side wall of the electrically insulating outer tank body defining the electrolytic solution supply tank. And the long workpiece to be fitted into the outlet side sliding port from the inlet side sliding port through the electrolytic solution supply tank at the predetermined speed to the outlet side sliding port side. A long-time treatment of a nuclear fuel cladding tube or the like, comprising: a transfer device for traveling toward the cathode; and a DC power supply unit in which the cathode side is connected to the cathode body and the anode side is conducted to the long material to be treated. An attempt is being made to provide an apparatus for producing a surface oxide film on a material.

According to a second aspect of the present invention, there is provided an electrically insulating outer tank,
An electrolyte supply tank formed by the electrically insulating outer tank body and the cathode body, between the electrolyte outlet and the electrolyte inlet of the electrolyte supply tank, and by circulating the electrolyte, the electrolyte solution Elongated material to be processed is provided on the electrolyte circulation channel continuously provided to remove air bubbles therein, and on the inlet side wall and the outlet side wall of the electrically insulating outer tank body defining the electrolyte supply tank. An inlet-side sliding contact and an outlet-side sliding contact that are fitted in a liquid-sealed state are provided therethrough, and are fitted from the inlet-side sliding contact to the outlet-side sliding contact through the inside of the electrolytic solution supply tank. A transfer device for moving the elongated workpiece at a predetermined speed toward the outlet side sliding contact port side, and a DC power supply in which the cathode side is connected to the cathode body and the anode side is connected to the elongated workpiece. And a device for forming a surface oxide film on a long material to be treated, such as a nuclear fuel cladding tube, comprising: We are trying to test.

Further, in claim 3 according to claim 1 or claim 2, the conduction between the anode side of the DC power supply unit and the long workpiece is established at one or both of the elongated ends of the long workpiece. An anode connector to be detachably attached, comprising: a contact contacting the thinned end; and an anode lead wire led out of the contact and connected to the anode, and the anode connector The electrically insulating outer cylinder has an outer diameter that can be fitted in the inlet-side sliding contact and the outlet-side sliding contact of the electrolytic solution supply tank, and the sliding contact length of the inlet-side sliding contact and the outlet-side sliding contact is equal to or longer than the sliding length. Its content is that it is formed in a length dimension.

An apparatus for forming a surface oxide film on a long material to be treated such as a nuclear fuel cladding tube according to a fourth aspect of the present invention comprises an electrically insulating outer tank body, and the electrically insulating outer tank body and the cathode body. The long material to be treated is fitted in a liquid-sealed state to the formed electrolyte supply tank and the inlet side wall and the outlet side wall of the electrically insulating outer tank body defining the electrolyte supply tank. The inlet-side sliding contact and the outlet-side sliding contact are provided through, and the inlet-side sliding contact is fitted to the outlet-side sliding contact through the electrolytic solution supply tank, and further into the electrically insulating outer tank body. A transfer device section that enters the inlet-side fitting port of the adjacent washing water tank and allows the long workpiece to be inserted into the outlet-side fitting port through the washing water tank to travel at a predetermined speed; and The cathode side is connected to the cathode body, and the anode side is composed of a DC power supply section which is conducted to the long workpiece. Are the contents.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Claims 1 to 3 of the present invention
In the following, FIG. 1 to FIG.
As can be understood from FIGS. 1 and 2 (A), in the illustrated example, the electrically insulating outer tank body 1 formed in a cylindrical shape or a rectangular tube shape is provided with:
In addition, a cylindrical or square-shaped cathode body 2 is provided in a horizontal direction in the illustrated example, so that the cathode body 2 and the inlet side wall of the electrically insulating outer tank body 1 which are installed facing each other. The electrolytic solution supply tank 4 is defined by the portion 3a and the outlet side wall portion 3b.

The entrance side wall 3a has an entrance side sliding contact 4
a, the outlet side wall 3b is provided with an outlet side sliding contact port 4b at a position facing each other, and the nuclear fuel cladding tube or the like which is entered in a liquid sealed state from the inlet side sliding contact port 4a.
The long material to be treated M having a circular end surface or the like and made of metal is also configured to be fitted into the outlet side sliding contact opening 4b in a liquid-sealed state.
Is formed considerably smaller than the length of the long material to be processed M.

Here, as described above, in order to make the entrance side sliding contact port 4a and the exit side sliding contact port 4b run in the direction of arrow A while sliding the long material to be processed M in the liquid sealing state, As shown in the figure, a ring-shaped inlet packing 4A and an outlet packing 4B made of rubber or synthetic resin are connected to the inlet side wall 3 respectively.
a and the outlet side wall 3b. And
In order to make the long material to be processed M travel in the direction of arrow A,
A transfer device unit 5 is provided, and a DC power supply unit 6 for conducting the anode side P to the long workpiece M and the cathode side N to the cathode body 2 is provided.

Although various structures can be adopted for the transfer unit 5, the running speed of the long material to be processed M can be controlled in the illustrated example as shown in FIGS. A receiving drive roller 5b, which is rotatably driven by the transfer power source 5a, and a play suppressing roller 5c, which is disposed on the upper side of the receiving drive roller 5b, are provided, for example, on the front side of the inlet side wall 3a. On the trailing side of the travel, a long workpiece M can be rotatably sandwiched between the receiving idler roller 5d and the idler roller 5e. As for these roller groups, it is preferable to use a drum-shaped roller group as shown in FIG.

Next, the electric connection means of the DC power supply section 6 will be described. The cathode N may be connected to the cathode body 2 by passing the cathode lead wire N1 through the electrically insulating outer tank body 1. On the other hand, also on the anode side P, the anode lead wire P1 shown in the figure may be connected to one end of the long material to be processed M or the like by appropriate means.

However, when the connecting means as specified in claim 3 is used, as shown in FIG. 2, the anode connector 6A is attached to one end or, if necessary, both sides of the elongated workpiece M. Like that. That is, in this case, the anode connector 6A is removably fitted to one or both of the narrow ends M1 provided in both the longitudinal directions of the long workpiece M in the longitudinal direction.

In FIG. 2B, the anode connector 6A is in contact with the narrowed end portion M1.
Anode lead wire P1 derived from this and conducting to anode side P
And an electrically insulating outer cylinder 6b in which the contact 6a is fitted. In the figure, reference numeral 6c denotes a fitting opening of the electrically insulating outer cylinder 6b. Anode connector 6A
Is reduced by the elasticity of the contact 6a as described above.
In addition to the pressure contact, a pressing screw (not shown) may be separately used for pressing.

Further, in the above-mentioned anode connector 6A, the outer diameter of the electrically insulating outer cylinder 6b is fitted in the inlet-side sliding contact port 4a and the outlet-side sliding contact port 4b in the electrolytic solution supply tank 4, so that a liquid-tight state is obtained. And the length L1 of the electrically insulating outer cylinder 6b is equal to or greater than the sliding length L2 of the entrance side sliding contact port 4a and the exit side sliding contact port 4b. Have been.

Therefore, with this configuration, FIG.
As clearly indicated by the above, the long material to be treated M is supplied to the electrolytic solution supply tank 4.
The anode connector 6A
Is inserted into the sliding contact opening 4a on the inlet side, the elongated workpiece M can travel until the tip of the anode connector 6A enters the electrolytic solution supply tank 4. The electrolytic treatment can be completely performed up to the terminal portion M2 except for the end portion M1.

If the anode connector 6A as described above is fitted to the other end M1 as well, a complete electrolytic surface treatment can be performed on the terminal M2 as described above.
In this case, instead of the anode connector 6A, FIGS.
A cap 6B formed in a similar size as shown in FIG.

Therefore, when the apparatus for forming a surface oxide film according to the first and second aspects is used, a long sliding contact port 4a and a small sliding contact port 4b in the electrolytic solution supply tank 4 are provided. After fitting the front end side of the material to be treated M, in the illustrated example, the electrolyte E is supplied from the electrolyte inlet 1a provided at the upper part of the electrolyte supply tank 4 until the electrolyte E is filled with a 1 wt% NaOH aqueous solution or the like, By fitting the anode connector 6A to the thinned end portion M1, between the long workpiece M and the cathode body 2,
A voltage of about 40 to 60 V is applied by the DC power supply unit 6.

Next, by operating the transfer unit 5, the long workpiece M is transferred in the direction of the arrow A by the transfer power source 5a at the traveling speed adjusted in advance. At this time, if the time during which the long material to be treated M is in contact with the electrolytic solution is set to about 10 to 30 seconds, the long material to be treated M is continuously and uniformly oxidized over its entire length. A film can be produced. In practice, it has been confirmed that the film pressure of the surface oxide film is about 500 nm, and the film thickness is controlled by adjusting the voltage applied by the DC power supply unit 6 and the traveling speed of the long workpiece M. It was also found that it could be changed.

Here, claim 2 will be described.
As described above, an electrolyte circulation channel 7 is added to the configuration of the first aspect. That is, not only the above-described electrolyte inlet 1a but also the electrolyte outlet 1b is provided upright on the upper part of the electrically insulating outer tank 1, and the electrolyte E is circulated between these two openings. Then, the electrolytic solution E
If the air bubbles in the inside, that is, the NaOH aqueous solution is an electrolytic solution, hydrogen will be generated in the cathode plate 2 and air bubbles as oxygen will be generated in the long material to be processed M as the anode. The electrolyte circulation channel 7 is connected in series. In this way, according to the second aspect, it is possible to efficiently and sufficiently generate an oxide film on the surface of the long material to be processed M. Here, the electrolytic solution circulation channel 7 illustrated in FIG.
a and the liquid sending pump 7b are connected, and 7c denotes a bubble discharge port.

FIG. 4 illustrates the technical contents of the fourth embodiment. The basic structure of the fourth embodiment is the same as that of the first embodiment. The cleaning water tank 8 is disposed next to the electrically insulating outer tank body 1 thus provided. In the cleaning water tank 8, the long material to be processed M, in which the surface oxide film has been formed in the electrolytic solution E in the previous stage, is cleaned. The cleaning is performed by the operation of the transfer device unit 5. This is done in a series of transfer steps.

For this reason, according to the fourth aspect, the long material to be processed M sent from the outlet side sliding contact port 4b of the electrically insulating outer tank body 1 is allowed to travel as it is to perform the cleaning. Entrance side entrance 8 of entrance tub wall 8a in water tub 8
b. Further, after the distilled water W is sprayed on the running long material to be processed M from the washing water jetting port 8e penetrating through the upper wall of the washing water tank 8, the outlet side fitting of the outlet tank wall 8c. In FIG. 4, 8f denotes a washing water discharge port provided on the lower wall, and 5f and 5g are provided near the outlet side fitting port 8d. And the idler roller and the idler roller at the final stage of the transfer device section 5 respectively.

[0029]

According to the first aspect of the present invention, since the present invention is constituted as described above, the long material to be treated is not immersed in the large electrolytic tank, but is simply immersed in the electrolytic solution supply tank. Since it is possible to generate a surface oxide film by electrolysis while passing through the liquid, the equipment site and equipment scale can be significantly reduced compared to the conventional technology, and industries that require the generation of this type of surface oxide film Great for the world.

In the second aspect, an electrolyte circulation channel is added to the configuration of the first aspect, so that air bubbles generated by the electrolytic surface treatment can be positively removed. Even if the material is transported at a considerable traveling speed, a desired surface oxide film can be generated, and the generation efficiency can be improved.

According to a third aspect of the present invention, in the first or second aspect, the anode connector having an appropriate size and configuration provides:
Because the anode side of the DC power supply unit is electrically connected to the long workpiece so that it can be freely attached and detached, work processing when using this type of device can be performed quickly and smooth long workpieces can be processed. The traveling can be ensured, and the generation of the entire surface oxide film over the entire length of the long workpiece can be guaranteed.

According to the fourth aspect, in addition to the configuration of the first aspect, the cleaning water tank is appropriately disposed, so that not only the formation of the surface oxide film but also the subsequent cleaning processing is performed in a series. The final process product in which the surface oxide film is generated can be promptly provided.

[Brief description of the drawings]

FIG. 1 is a schematic front view showing an entire configuration of a partially cut-out according to an embodiment of the present invention.

2 (A) is a perspective view showing an electrically insulating outer tank body in FIG. 1, and FIG. 2 (B) is a longitudinal sectional front view of a main part showing a connection state between a long workpiece and an anode connector. .

3A is an enlarged front view showing the transfer device in FIG. 1, and FIG. 3B is a cross-sectional view taken along line BB of FIG.

FIG. 4 is a schematic front view showing the entire configuration of a partially cutaway showing one embodiment of the fourth aspect of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrically insulating outer tank body 1a Electrolyte inlet 1b Electrolyte outlet 2 Cathode body 3a Inlet side wall part 3b Outlet side wall part 4 Electrolyte supply tank 4a Inlet side sliding contact port 4b Outlet side sliding contact port 5 Transfer device part 6 DC power supply part 6A Anode connector 6a Contact 6b Electrically insulating outer cylinder 7 Electrolyte circulation channel 8 Washing water tank 8b Inlet-side mating port 8d Outlet-side mating port E Electrolyte L2 Sliding length M Long material to be treated M1 Narrowed end N Cathode side P Anode side P1 Anode lead wire

Claims (4)

[Claims] 1. An electric insulating outer tank body, an electrolytic solution supply tank formed by the electric insulating outer tank body and the cathode body, and an electric insulating outer tank body defining the electrolytic solution supply tank. The inlet side wall portion and the outlet side wall portion are provided with an inlet side sliding contact port and an outlet side sliding contact port through which a long material to be processed is fitted in a liquid-sealed state, respectively. A transfer device for moving the long workpiece to be fitted into the outlet-side sliding port through the electrolytic solution supply tank toward the outlet-side sliding port at a predetermined speed; An apparatus for forming a surface oxide film on a long material to be treated such as a nuclear fuel cladding tube, the device comprising a DC power supply connected to the anode and connected to the long material to be treated. 2. An electric insulation outer tank, an electrolyte supply tank formed by the electric insulation outer tank and the cathode body, and a gap between an electrolyte outlet and an electrolyte inlet of the electrolyte supply tank. The electrolytic solution is circulated to remove the bubbles in the electrolytic solution, and an electrolytic solution circulating flow path, and an inlet side wall of an electrically insulating outer tank body that defines the electrolytic solution supply tank. An inlet-side sliding contact and an outlet-side sliding contact with which a long material to be treated is fitted in a liquid-sealed state are provided through the inlet side and the outlet side wall, respectively. A transfer device for moving the long workpiece to be fitted into the outlet sliding contact port through the tank toward the outlet sliding contact port side at a predetermined speed, and the cathode side is connected to the cathode body, A long-side treatment, such as a nuclear fuel cladding tube, characterized in that the anode side comprises a DC power supply section which is conducted to the long-side treatment material. A device that generates a surface oxide film on a base material. 3. An anode connector which is detachably attached to one or both of the elongated ends of the elongated material, wherein conduction between the anode side of the DC power supply unit and the elongated material to be processed is provided. A contact that comes into contact with the thinned end portion, and an anode lead wire that is led out of the contact and is electrically connected to the anode side, and the electrically insulating outer cylinder of the anode connector is provided in the electrolyte supply tank. 2. The method according to claim 1, wherein the outer sliding contact port and the inlet sliding contact port have an outer diameter capable of being fitted inside the sliding contact port and have a length equal to or greater than the sliding contact length of the inlet sliding contact port and the outlet sliding contact port. 3. An apparatus for forming a surface oxide film on a long material to be treated such as the nuclear fuel cladding tube according to 2. 4. An electric insulating outer tank body, an electrolytic solution supply tank formed by the electric insulating outer tank body and the cathode body, and an electric insulating outer tank body defining the electrolytic solution supplying tank. The inlet side wall portion and the outlet side wall portion are provided with an inlet side sliding contact port and an outlet side sliding contact port through which a long material to be processed is fitted in a liquid-sealed state, respectively. The outlet-side sliding contact port is fitted through the electrolytic solution supply tank, and further enters the inlet-side sliding port in the washing water tank adjacent to the electrically insulating outer tank body, and is fitted through the washing water tank through the outlet side. A transfer device section for running a long workpiece to be inserted into the sliding port at a predetermined speed, and a DC power supply section in which the cathode side is connected to the cathode body and the anode side is connected to the long workpiece. An apparatus for forming a surface oxide film on a long workpiece to be treated such as a nuclear fuel cladding tube.