JP3799679B2 - Anticorrosion method for structures - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a corrosion prevention method of the structure, particularly, the invention relates to the corrosion protection method Structures allow the anticorrosive coating treatment of large areas with less power by low current and constant voltage method.
[0002]
[Prior art]
For example, a ship's ballast tank is placed in a severe corrosive environment in order to inject seawater into the interior, and much of the damage that occurs in structural members is due to corrosion and wear.
[0003]
For this reason, as shown in FIG. 8, the anti-corrosion measures for the ballast tank are basically such that the inner wall b of the ballast tank a is covered with the coating film c by coating the inner wall b of the ballast tank a to form the coating film c. In order to provide a general anticorrosive property, and to prevent corrosion caused by contact of seawater with the defective portion of the coating film c when the coating film c is defective for any reason, the tank inner wall b Part of uncoated part d of paint is partially formed, backup anode e such as zinc or aluminum piece is welded and fixed to uncoated part d, and the potential difference between steel tank inner wall b and backup anode e is utilized. Thus, corrosion of defective portions of the coating film c is prevented.
[0004]
[Problems to be solved by the invention]
In the conventional means described above, an operator enters the ballast tank a and manually performs the painting operation. In this case, it is difficult to uniformly apply the coating to the whole, and therefore it is difficult to maintain the consistency of the technology. In addition, there is a problem that the quality of the coating film c is difficult to stabilize, and further commercialization is difficult.
[0005]
In view of the above circumstances, the present invention eliminates the need to perform a painting operation, maintains the consistency of the technology, and stabilizes the quality of the coating applied to the surface of the structure. It was made for the purpose of providing a method for preventing corrosion of structures that could be commercialized.
[0006]
[Means for Solving the Problems]
The invention relating to this method determines the current value output from the power source based on the number of anodes connected to the power source and the area to be subjected to the anticorrosive coating treatment of the structural steel body, and submerses in the electrolyte. When a predetermined current output from the power source is applied to the anode and a cation such as Ca ²⁺ or Mg ²⁺ is deposited by electrolysis of an electrolytic solution to form an anticorrosion film on the structural steel body, thereby forming an anticorrosion film In addition, whether the anticorrosion film treatment is performed satisfactorily by measuring the current flowing from the anode to the structural steel body that performs the anticorrosion film treatment, the potential difference applied between the reference electrode and the structural steel body, and the temperature of the electrolyte. Monitoring .
[0007]
[0008]
Another invention related to this method determines the current value output from the power source based on the number of anodes connected to the power source and the area to be subjected to the anticorrosive coating treatment of the structural steel body, and is immersed in the electrolyte. A first step of applying a predetermined current output from the power source to a watered anode and forming a corrosion-resistant coating on the structural steel body by electrolysis of an electrolytic solution;
A second step of immersing the sacrificial anode having a higher ionization tendency than the structural steel body to be subjected to the anticorrosive film treatment in the electrolytic solution and forming the anticorrosive film on the structural steel body by electrolysis of the electrolytic solution ,
When forming the anticorrosive film in the first step, by measuring the current flowing from the anode to the structural steel body that performs the anticorrosive film treatment, the potential difference applied between the reference electrode and the structural steel body, and the temperature of the electrolyte solution Monitor whether the anti-corrosion coating is performed well,
When the anticorrosion film is formed in the second step, the current flowing from the sacrificial anode to the structural steel body that performs the anticorrosion film treatment, the potential difference applied between the reference electrode and the structural steel body, and the temperature of the electrolyte solution are measured. Thus, it is monitored whether or not the anticorrosion film treatment is satisfactorily performed .
[0009]
[0010]
[0011]
[0012]
In this how onset bright, construction quality of anticorrosive film that has been subjected to the steel body is stable and anticorrosive film of large area with less power by low current and constant voltage method it is possible to maintain consistency of the technology Since it can be processed, commercialization is easy.
[0013]
When the structure is a ship when the anticorrosion film treatment is performed separately in the first step and the second step in the invention of the present method, the anticorrosion film is formed while the ship is in service in the second step. Can do.
[0014]
In the present invention, when the anticorrosion film is formed, the current flowing from the anode or the sacrificial anode to the structural steel body that performs the anticorrosion film treatment, the potential difference applied between the reference electrode and the structural steel body, and the temperature of the electrolyte solution are measured. Therefore, since it is monitored whether or not the anticorrosion film treatment is performed satisfactorily, a good anticorrosion film can be obtained.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0016]
FIGS. 1-7 is an example of embodiment of this invention, FIGS. 1-4 shows the means of the 1st step, and FIGS. 5-7 has shown the means of the 2nd step.
[0017]
First, the means of the first step will be described with reference to FIGS.
[0018]
In FIG. 2, 1 is a primary power source of 440V mounted on the ship 2, 3 is a control device that is operated by the power supplied from the primary power source 1, and 4 is a plurality of electrical devices that are electrically connected to the control device 3. The branch box 5 is an anode disposed in the ballast tank 2 a for performing anticorrosive coating treatment in the ballast tank 2 a of the ship 2 by power feeding from the branch box 4.
[0019]
Although two branch boxes 4 are shown in FIG. 2, there are actually six branch boxes 4 and up to 64 anodes 5 can be connected to one branch box 4.
[0020]
As shown in FIG. 1, the control device 3 receives electricity from the primary power source 1 (see FIG. 2), transforms it to 200 V and 100 V, and receives power from the power receiving panel 6 and the power receiving panel 6. Operates with 100V electricity and sets various data at the time of anticorrosive coating treatment, and operates with 200V electric power from PC 7 for receiving various measured data and receiving board 6 and is electrically connected to PC 7 The control panel 8 is provided with a plurality of power sources 9 that operate in accordance with commands from the control panel 8 and perform constant current operation for supplying power to the anode 5 via the control panel 8 and the branch box 4. In FIG. 1, two power power supplies 9 are shown, but in reality, there are six, and the number of branch boxes 4 corresponds one-to-one.
[0021]
In FIG. 1, reference numeral 10 denotes a current detector, ballast, which is stored in a ballast tank 2a containing seawater (see FIG. 2) and measures the current flowing from the anode 5 to the tank steel plate 11 (see FIG. 3). A data detector 5a such as a temperature detector that detects the temperature of the seawater stored in the tank 2a is a reference electrode that is stored in the ballast tank 2a and measures a potential difference with the tank steel plate 11.
[0022]
Next, the method of the 1st step which performs the anti-corrosion film process in the ballast tank 2a of the ship 2 shown in FIG. 2 using the apparatus of FIG. 1, 2 is demonstrated, referring also to FIG.
[0023]
As shown in FIG. 3, a shop primer 12 is applied to a tank steel plate 11 that is a structural member of the ballast tank 2 a in order to prevent corrosion during the construction period of the ship 2. The shop primer 12 is broken due to cutting, welding, or the like of the tank steel plate 11 in the assembly stage, and rust is partially generated by long-term exposure.
[0024]
Therefore, after the assembly of the hull is completed, seawater is put into the ballast tank 2a during the outfitting period after the launch, and a current of a predetermined strength is applied from the power source 9 of FIG. The electric current 13 is generated, and an operation of generating and attaching the anticorrosion film 14 to the defective portion and the rust portion of the shop primer 12 by electrolysis of seawater is performed.
[0025]
That is, a predetermined voltage is supplied from the primary power source 1 to the personal computer 7 and the control panel 8 via the power receiving panel 6. First, the personal computer 7 is started up and various data necessary for the anticorrosive coating treatment are set in the personal computer 7. The data to be set includes the following items, for example.
i. File name for storing stored data
ii. Number of anode 5 connections per power source 9
iii. Coating area for each block shown in FIG. 4 (m ² )
iv. No. of the block to which the power supply 9 belongs.
v. Operating time (min.)
vi Potential difference measurement points (maximum 3 points)
vii. Current measurement points (up to 3 points)
viii. Temperature measurement points (up to 4 points)
[0026]
Such i. When the operation shown in -viii is input to the personal computer 7 and the operation is started, the personal computer 7 determines the power from the number of anodes 5 connected to the power power source 9 per unit and the area of the tank steel plate 11 to be subjected to the anticorrosive coating treatment. The current output set value (current amount) per unit of the power supply 9 is calculated by [Equation 1], and the current output set value is given to the power power supply 9 via the control panel 8.
[0027]
[Expression 1]
I = IT / 6 = CT × (S / t) × (1/6)
[0028]
However, [Equation 1] holds when M ≧ IT / 5, where M is the number of anodes, I is the amount of current per unit of power supply 9 (A), and IT is the total current. The amount (A) and CT are the total energization amount (A · day / m ² ), S is the coating area (m ² ), and t is the energization time (day).
[0029]
Thus, the power power source 9 performs a constant current operation in accordance with the current output set value command from the control panel 8, and a predetermined output voltage and current value are returned to the control panel 8. Is fed to the anode 5 via the branch box 4. Therefore, a current 13 flows from the anode 5 to the tank steel plate 11 functioning as a cathode as shown in FIG. 3, and thus cations such as Ca ²⁺ and Mg ²⁺ are precipitated from seawater, and the shop primer of the tank steel plate 11 is obtained. The anticorrosive film 14 is formed by adhering to the portion having no twelve.
[0030]
On the other hand, the potential difference between the current detected by the data detector 10 and various data such as the temperature of the seawater stored in the ballast tank 2a and the tank steel plate 11 measured by the reference electrode 5a is determined by the branch box 4. Is given to the personal computer 7 through the control panel 8 and stored as data on a floppy disk or the like. These data are used as data for monitoring whether or not the anticorrosion film treatment is being performed satisfactorily and at the same time as data for the anticorrosion film treatment at other locations. Further, by providing a printer, these data may be printed out as a table or a graph as appropriate.
[0031]
Further, the output voltage and current value from the power supply 9 are also supplied from the control panel 8 to the personal computer 7 and stored as data in a floppy disk or the like. This data is the cumulative consumption of zinc (Zn) at the anode 5. Used for calculation.
[0032]
The calculation of Zn integrated consumption is performed by [Equation 2].
[0033]
[Expression 2]
Zn integrated consumption (g / m ² )
= [1.22 (g / A · hr) × current value (A) × time (hr)] / area of the corresponding block for the anticorrosion coating treatment (m ² )
[0034]
In [Expression 2], 1.22 is the system constant, the current value is the sum of the output current values of the power supply 9 in the predetermined block (see FIG. 4), and the time is the elapsed time during which the anticorrosion coating treatment is performed. is there.
[0035]
The accumulated Zn accumulated consumption is also taken into the floppy disk of the personal computer 7.
[0036]
When the initially set time has elapsed, the supply of the output voltage and current from the power source 9 to the anode 5 and the anticorrosion coating process are completed.
[0037]
As described above, by supplying a predetermined output voltage and current value from the power source 9 to the anode 5 and performing the anticorrosion coating, the anticorrosion coating can be performed by a low voltage constant current method. The inner surface of the tank 2 a is in a state where there is no unprotected surface due to the anticorrosion film 14 and the shop primer 12.
[0038]
In addition, by adopting the low voltage constant current method, a power transformer is not required, so that the power source 9 can be downsized (0 to 15 V, 200 A), and a large area can be treated with a small amount of electric power with a small power. Therefore, commercialization can be easily performed.
[0039]
If the power supply is not a low voltage constant current system, a power transformer is required, so the power supply becomes large, and a current of several thousand amperes is required, so the voltage must be increased, There are problems such as the need for a substation.
[0040]
Next, the means of the second step will be described with reference to FIGS.
[0041]
In FIG. 5, 15 is a personal computer that can be started up by an onboard power source, 16 is a control panel electrically connected to the personal computer 15, 17 is a branch box electrically connected to the control panel 16, and 18 is Data of a current detector for measuring the current flowing from the sacrificial anode 19 to the tank steel plate 11 stored in a ballast tank containing seawater, a temperature detector for detecting the temperature of the seawater stored in the ballast tank, etc. The detector 19a is a reference electrode that is housed in the ballast tank and measures a potential difference with the tank steel plate. The sacrificial anode 19 and the reference electrode 19a are disposed and fixed in the ballast tank.
[0042]
Next, the method of the 2nd step which performs anti-corrosion film processing in the ballast tank 2a of the ship 2 shown in FIG. 6 using the suspicious anode 19 is demonstrated.
[0043]
Since the tank steel plate 11 of the ballast tank 2a is exposed to a severe corrosive environment, the shop primer applied to the tank steel plate 11 is gradually lost over time, but the shop primer of the tank steel plate 11 is lost. The method of the 2nd step of this Embodiment is applied to the place where it was.
[0044]
That is, first, the personal computer 15 is started up, and various data necessary for performing the anticorrosive film treatment are set in the personal computer 15. The data to be set includes the following items, for example.
i. File name for storing stored data
ii. Name of potential measurement point
iii. Name of current measurement point
iv. Current measurement point block
v. Coating area for each block (m ² )
vi Temperature measurement point name
vii. Operating time [0045]
Since the second step uses a sacrificial anode 19 of zinc steel or the like, the difference in ionization tendency between the sacrificial anode 19 and the tank steel 11, the current 20 flows from the sacrificial anode 19 in the tank steel 11 flows Then, cations such as Ca ²⁺ and Mg ²⁺ are precipitated from the seawater stored in the ballast tank 2a, adhere to the tank steel plate 11 constituting the ballast tank 2a, and the anticorrosion film 14 is formed.
[0046]
Thus, in response to the measurement start instruction, various data such as current and temperature are taken from the data detector 18 to the personal computer 15 via the branch box 17 and the control panel 16, and stored as data on the floppy disk. The potential difference from the reference electrode 19a is also taken into the personal computer 15 in the same way as various data and is stored as data on the floppy disk. As in the case of the first step, these data are used as monitoring material for determining whether or not the anticorrosion film treatment is being performed satisfactorily, and also used as a material when the anticorrosion film treatment is performed at another place. Note that the operation time and the measurement time are considered to be equal, and the operation is performed with reference to the time during which the film formation state is stabilized.
[0047]
Further, from the accumulated data, the integrated Zn consumption is obtained by [Equation 2] and accumulated in the floppy disk of the personal computer 15. However, in the case of the second step, the current value in [Expression 2] is the total sum of the galvanic anode currents in the corresponding block.
[0048]
According to the method of the second step, not only the anticorrosive film treatment of the lost part of the shop primer but also the initial film is reinforced.
[0049]
Further, in the second step, since the suspicious anode 19 is used, the anticorrosion coating treatment can be performed by storing seawater in the ballast tank 2a even after the ship enters service.
[0050]
According to the embodiment of the present invention, the anticorrosion film 14 is formed on the tank steel plate 11 using electrolysis, and it is not necessary to perform painting, so that the consistency of the technology can be maintained, and The quality of the formed anticorrosion film is stable and can be easily commercialized.
[0051]
Further, according to the present embodiment, in the first step, power is supplied from the power source 9 to the anode 5 to form the anticorrosion film 14, and in the second step, the suspicious anode 19 which is a simple device is used. Thus, the anticorrosion film 14 is formed. For this reason, the anticorrosion film treatment can be performed promptly until the ship enters service, and after the ship enters service, the anticorrosion film treatment can be performed slowly over time while navigating the ship.
[0052]
In addition, although the case where the thing made from zinc was used as an anode used for this Embodiment or a sacrificial anode was demonstrated, it can implement even if it uses the thing made from aluminum, not only a ship but in water, a bridge, and a marine structure Of course, the present invention can be applied to objects, dams, etc., the electrolytic solution can be hard water in addition to seawater, and various modifications can be made without departing from the scope of the present invention.
[0053]
【The invention's effect】
According to anticorrosion how the structure of the present invention, in any of the claims 1 and 2, the quality of the anticorrosive film that has been subjected to a structure it is possible to maintain consistency of the technology is stable and low Commercialization is easy because a wide area can be treated with a small amount of power by using the voltage constant current method, and monitoring of whether the anticorrosion film is well formed from various data obtained during the anticorrosion film treatment. In the case of claim 2, when the structure is a ship, the anti-corrosion film is formed while the ship is in service in the second step. it is, can achieve equal various excellent effects.
[Brief description of the drawings]
[1] Oite anticorrosive method of the structure of the present invention, is a schematic block diagram of an apparatus used in the first step.
FIG. 2 is a schematic side view of performing an anticorrosive coating treatment by mounting an apparatus applied to the anticorrosion method of the present invention on a ship.
FIG. 3 is a side view for explaining the principle when the anticorrosion film treatment is performed by the apparatus shown in FIG. 1;
4 is a conceptual diagram showing an example in which a power source and an anode in the apparatus of FIG. 1 are blocked.
[5] Oite anticorrosive method of the structure of the present invention, is a schematic block diagram of apparatus used in the second step.
6 is a schematic side view of carrying out the anticorrosion coating treatment by mounting the apparatus shown in FIG. 5 on a ship. FIG.
FIG. 7 is a side view for explaining the principle when the anticorrosion film treatment is performed by the apparatus shown in FIG.
FIG. 8 is a partial cross-sectional side view of a tank steel plate for explaining a conventional example.
[Explanation of symbols]
5 Anode 5a, 19a Reference electrode 7 Personal computer (control data setting monitoring device)
8 Control panel 9 Power supply 10, 18 Data detector 11 Tank steel plate (steel structure)
14 Anticorrosion coating 19 Sacrificial anode

Claims (2)

The current value output from the power source is determined based on the number of anodes connected to the power source and the area to be subjected to the anticorrosive coating treatment of the structural steel body, and the power source is connected to the anode immersed in the electrolyte. When applying a predetermined current output from the electrolytic solution and depositing cations such as Ca ²⁺ and Mg ²⁺ by electrolysis of the electrolytic solution to form an anticorrosion film on the structural steel body, the anticorrosion film is formed from the anode. Monitoring whether the anticorrosion coating treatment is being performed satisfactorily by measuring the current flowing to the structural steel body to be treated, the potential difference applied between the reference electrode and the structural steel body, and the temperature of the electrolyte. A method for preventing corrosion of a structure. The current value output from the power source is determined based on the number of anodes connected to the power source and the area to be subjected to the anticorrosive coating treatment of the structural steel body, and the power source is connected to the anode immersed in the electrolyte. A first step of applying a predetermined current output from the above and forming an anticorrosion film on the structural steel body by electrolysis of an electrolytic solution;
A second step of immersing the sacrificial anode having a higher ionization tendency than the structural steel body to be subjected to the anticorrosive film treatment in the electrolytic solution and forming the anticorrosive film on the structural steel body by electrolysis of the electrolytic solution,
When forming the anticorrosive film in the first step, by measuring the current flowing from the anode to the structural steel body that performs the anticorrosive film treatment, the potential difference applied between the reference electrode and the structural steel body, and the temperature of the electrolyte solution Monitor whether the anti-corrosion coating is performed well,
When performing the anticorrosive film treatment in the second step, measure the current flowing from the sacrificial anode to the structural steel body that performs the anticorrosive film treatment, the potential difference applied between the reference electrode and the structural steel body, and the temperature of the electrolytic solution. The method for preventing corrosion of a structure is characterized by monitoring whether or not the anticorrosion film treatment is satisfactorily performed .

Images