JPH11286793A - Cathodic corrosion protecting method for metallic structure, and device therefor - Google Patents

Cathodic corrosion protecting method for metallic structure, and device therefor

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Publication number
JPH11286793A
JPH11286793A JP10093187A JP9318798A JPH11286793A JP H11286793 A JPH11286793 A JP H11286793A JP 10093187 A JP10093187 A JP 10093187A JP 9318798 A JP9318798 A JP 9318798A JP H11286793 A JPH11286793 A JP H11286793A
Authority
JP
Japan
Prior art keywords
metal
anode
current
pilot
cathodic protection
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP10093187A
Other languages
Japanese (ja)
Other versions
JP4148373B2 (en
Inventor
Masahiro Takahashi
Yasuhiko Takahashi
Eisuke Wada
英輔 和田
正浩 高橋
靖彦 高橋
Original Assignee
Tac:Kk
株式会社タック
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tac:Kk, 株式会社タック filed Critical Tac:Kk
Priority to JP09318798A priority Critical patent/JP4148373B2/en
Publication of JPH11286793A publication Critical patent/JPH11286793A/en
Application granted granted Critical
Publication of JP4148373B2 publication Critical patent/JP4148373B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Abstract

PROBLEM TO BE SOLVED: To provide a cathodic corrosion protecting method for a metallic structure and a device therefore, by which the range enabling the corrosion protection with one anode can be enlarged to the max. while avoiding excessive corrosion protection, in the electric corrosion protection for the metallic structure. SOLUTION: A main anode 15 and a pilot anode 20 are fitted onto the coated film 17 of the metallic structure 16 and also, a cathode is fitted to a metallic material of the metallic structure 16. Then, a prescribed voltage is impressed to the metallic structure 16 from the pilot anode 20 and the necessary corrosion protecting current to the metallic structure 16 is read out from the current value of the pilot anode 20 changed according to the variation of the corrosive environment of the metallic structure 16 and the impressed voltage of the main anode 15 while linking with this current value is changed.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION
【0001】[0001]
【発明の属する技術分野】本発明は、建物の外壁、屋
根、橋梁などの大気中に暴露されている金属製構造物が
酸化腐食されるのを電気的システムにより防止する陰極
防食法および装置に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cathodic protection method and apparatus for preventing, by an electric system, oxidative corrosion of metal structures exposed to the atmosphere, such as building exterior walls, roofs and bridges. .
【0002】[0002]
【従来の技術】大気中に暴露されている金属製構造物
は、その金属表面が塗装されていても、経時的に、雨水
や空気中の湿気と大気中の汚染物質等によってその表面
に形成される電解質水分とこの水分中の溶存酸素とによ
り、酸化腐食される。
2. Description of the Related Art A metal structure exposed to the atmosphere is formed on the surface by rainwater or moisture in the air and pollutants in the air over time, even if the metal surface is painted. Oxidative corrosion is caused by the electrolyte water and dissolved oxygen in the water.
【0003】このような金属製構造物の塗装面の防食を
行う保護陽極および陰極防食システムとして、シー・エ
ル・アイ・システムズ・インコーポレイテッド(米国)
が開発し、市販している装置がある(特願平3−306
342号)。
[0003] As a protective anode and cathodic protection system for protecting the painted surface of such a metal structure, CIL Systems Inc. (USA)
There is a device developed and marketed (Japanese Patent Application No. 3-306).
342).
【0004】この電気防食装置は、大気中に暴露され、
塗装により表面を保護されている金属製構造物の腐食防
止に効果を発揮しているが、以下の2点の問題点は避け
られないでいる。すなわち、 (1) 構成要素である電流制御手段は、湿度感応素子
により検知される環境湿度に正比例する値の電流を流す
機能を持たされている。しかし、実際には、海塩粒子や
大気汚染物質が水膜に溶存する度合いによって、同じ湿
度で水膜の厚さが同じであっても、明らかに、水膜自体
の単位長さ当たりの電気抵抗は大きく異なってくる。そ
のため、水膜の水質によって、防食に必要な電流量は変
わってくるので、同じ電流量を印加しても、そのときの
環境水質により、防食電流の到達範囲にも変動が生じ
る。
[0004] This cathodic protection device is exposed to the atmosphere,
Although effective in preventing corrosion of metal structures whose surfaces are protected by painting, the following two problems cannot be avoided. That is, (1) the current control means, which is a component, has a function of flowing a current having a value directly proportional to the environmental humidity detected by the humidity sensitive element. However, in reality, depending on the degree to which sea salt particles and air pollutants are dissolved in the water film, even if the thickness of the water film is the same at the same humidity, it is obvious that the electric power per unit length of the water film itself is apparent. Resistance will vary greatly. Therefore, the amount of current required for anticorrosion varies depending on the water quality of the water film. Therefore, even when the same amount of current is applied, the reach of the anticorrosion current varies depending on the environmental water quality at that time.
【0005】また、金属構造物の表面塗装の塗膜は、砂
塵、その他の環境中の影響因子により、部分的に劣化さ
れ、その一部に欠陥が生じる。この欠陥部位が拡大する
と、環境湿度が同じでも、欠陥部位をも含んだ金属構造
物の広範な表面の防食に必要な電流量は、大幅に増大す
る。例えば、水膜に多量の海塩粒子が溶け込んで、さら
に、塗膜の欠陥が、装置の保護陽極の周囲に発生した場
合を考えると、湿度が60〜70%と低湿度で、電流が
少量しか供給されないとすると、供給した電流は、前述
の欠陥部位に流れ込んでしまうため、保護陽極の周辺の
狭い範囲で消耗されることになり、防食電流の到達する
範囲が狭くなってしまう。
[0005] Further, a coating film for surface coating of a metal structure is partially degraded due to dust and other environmental influencing factors, and a part thereof is defective. When the defect site is enlarged, the amount of current required for preventing corrosion of a wide surface of the metal structure including the defect site is greatly increased even at the same environmental humidity. For example, considering a case where a large amount of sea salt particles are dissolved in a water film and a defect of a coating film is generated around a protective anode of the device, the humidity is low at 60 to 70% and the current is small. If only the supplied current is supplied, the supplied current flows into the above-described defective portion, so that the supplied current is consumed in a narrow range around the protective anode, and the range in which the anticorrosion current reaches is narrowed.
【0006】(2) 保護陽極近傍の金属製構造物の過
防食を防止するために、陽極の出力電圧を最大12Vと
している。しかし、前述のように、前記塗膜の欠陥部位
の領域が増大する場合、所期の範囲の防食を達成するた
めには、さらに電圧を高めて、電流を多く流してやる必
要がある。この必要に対して、最大12Vの出力電圧に
よる電流印加では、対応できない。
(2) The output voltage of the anode is set to a maximum of 12 V in order to prevent excessive corrosion of the metal structure near the protective anode. However, as described above, when the area of the defective portion of the coating film increases, it is necessary to further increase the voltage and to flow a large amount of current in order to achieve the desired range of corrosion protection. This need cannot be met by applying a current with an output voltage of 12 V at the maximum.
【0007】[0007]
【発明が解決しようとする課題】本発明は、前記従来の
事情を鑑みてなされたもので、その課題は、金属製構造
物の電気防食において、一つの陽極によって防食可能と
する範囲を、過防食を起こさずに、最大限にまで拡大す
ることのできる金属製構造物の陰極防食法および装置を
提供することにある。
SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to limit the range in which a single anode can prevent corrosion in a metal structure. It is an object of the present invention to provide a method and an apparatus for cathodic protection of metal structures which can be expanded to the maximum without causing corrosion protection.
【0008】[0008]
【課題を解決するための手段】本発明者らは、前記課題
を解決するために、下記のような実験検討を行い、本発
明をなすに至った。
Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have carried out the following experimental studies and completed the present invention.
【0009】実験では、各種システムを構築し、所期の
機能を果たせるか否か試行錯誤を重ね、図1に示すシス
テムを初期に作り上げた。
In the experiments, various systems were constructed, and trial and error were repeated to determine whether or not the desired functions could be achieved, and the system shown in FIG.
【0010】図中、1はAC100〜200V電源の端
子、2はヒューズ、3はサージ電流吸収のバリスターで
ある。4はトランスであり、出力を18〜20Vに落圧
する。また、5は整流回路であり、交流を直流に変換す
る。6、7はコンデンサーである。8はレギュレータで
あり、主陽極15に印加する電圧を制御する。9および
10はコンデンサーであり、21もコンデンサーであ
る。22はレギュレータであり、パイロット陽極20に
印加する電圧を一定値に制御する。23および24はコ
ンデンサーである。
In FIG. 1, reference numeral 1 denotes a 100 to 200 V AC power supply terminal, 2 denotes a fuse, and 3 denotes a surge current absorbing varistor. Reference numeral 4 denotes a transformer that reduces the output to 18 to 20V. Reference numeral 5 denotes a rectifier circuit that converts alternating current into direct current. 6 and 7 are condensers. Reference numeral 8 denotes a regulator that controls a voltage applied to the main anode 15. 9 and 10 are condensers, and 21 is also a condenser. A regulator 22 controls the voltage applied to the pilot anode 20 to a constant value. 23 and 24 are condensers.
【0011】以上の電源端子1ないしコンデンサー1
0、コンデンサー21、レギュレータ22、コンデンサ
ー23および24の各部品は、制御器30に収納されて
いる。
The above-mentioned power supply terminal 1 or capacitor 1
0, the condenser 21, the regulator 22, and the condensers 23 and 24 are housed in the controller 30.
【0012】トランジスター11、抵抗器12、14、
ツェナーダイオード13は、主陽極15に供給される電
流がある一定値以上流れないようにする第1の電流制限
手段100を構成している。また、コンデンサー25、
オペアンプ26、抵抗器27、28、29は、第2の電
流制限手段101を構成しており、パイロット陽極20
から防食対象である塗装鋼板(金属製構造物)16に流
れ込む電流を検出し、その電流検出値に応じて、レギュ
レータ8のグランドを介して該レギュレータ8の出力電
圧を制御し、それによって、所期の最適電流を主陽極1
5から塗装鋼板16に流す。主陽極15と塗装鋼板16
との間には、電気抵抗を有する特殊な媒体70を介在さ
せる。
The transistor 11, the resistors 12, 14,
The Zener diode 13 constitutes first current limiting means 100 for preventing the current supplied to the main anode 15 from flowing beyond a certain value. Also, the condenser 25,
The operational amplifier 26 and the resistors 27, 28 and 29 constitute a second current limiting means 101, and the pilot anode 20
Current flowing into a coated steel plate (metal structure) 16 to be protected from corrosion, the output voltage of the regulator 8 is controlled via the ground of the regulator 8 in accordance with the detected current value, whereby The optimal current for the main anode 1
5 to the coated steel plate 16. Main anode 15 and painted steel plate 16
A special medium 70 having an electric resistance is interposed between the media.
【0013】前記第1の電流制御手段100は、主陽極
15に一体化し、第2の電流制御手段101は、パイロ
ット陽極20に一体化する。なお、図中、17は防食対
象である塗装鋼板16に施した塗装の塗膜である。18
は前記塗膜17の欠陥部であり、19は塗装鋼板16の
表面に形成される水膜を示す。
The first current control means 100 is integrated with the main anode 15, and the second current control means 101 is integrated with the pilot anode 20. In the drawing, reference numeral 17 denotes a coating film applied to the coated steel plate 16 to be subjected to anticorrosion. 18
Denotes a defective portion of the coating film 17, and 19 denotes a water film formed on the surface of the coated steel plate 16.
【0014】前記構成の装置において、レギュレータ2
2の出力電圧を8V〜12Vのある一定値に制御し、水
膜19の電気伝導度の増大および欠陥部18の拡大によ
り電流が増加するとき、それに応じて、レギュレータ8
の出力電圧を10Vから例えば15Vまで上げて、所期
の最適防食電流を塗装鋼板16に供給する。
In the apparatus having the above configuration, the regulator 2
2 is controlled to a certain constant value of 8V to 12V, and when the current increases due to the increase in the electric conductivity of the water film 19 and the enlargement of the defective portion 18, the regulator 8
Is increased from 10 V to, for example, 15 V, and the desired optimal anticorrosion current is supplied to the coated steel plate 16.
【0015】図2は、図1に示した構成の電気防食装置
の防食機能を確認するための試験設備の概要を示すもの
である。塗装鋼板16に主陽極15およびパイロット陽
極20を絶縁性両面接合体を介して貼り付けた。制御器
30からのアノード線30a,30aを、対応する主陽
極15とパイロット陽極20に接続し、さらに、カソー
ド線30bを塗装鋼板17の母材32に接続した。
FIG. 2 shows an outline of a test facility for confirming the anticorrosion function of the cathodic protection device having the configuration shown in FIG. The main anode 15 and the pilot anode 20 were attached to the coated steel plate 16 via an insulating double-sided joined body. The anode wires 30a, 30a from the controller 30 were connected to the corresponding main anode 15 and pilot anode 20, and the cathode wire 30b was connected to the base material 32 of the coated steel plate 17.
【0016】塗装鋼板16の陽極取付位置から離れた位
置の塗膜の一部分を剥離し、直径10mmの人工の塗膜
欠陥部18を形成した。塗膜欠陥部18に飽和KClを
含む寒天でコーティングしたAg/AgCl微小電極
(φ=0.1mm)31を設置した。この電極31に対
する鋼板母材17の電位をバッファーを介してコンピュ
ータに出力させ、データ収集を行った。
A portion of the coating film away from the anode mounting position of the coated steel plate 16 was peeled off to form an artificial coating defect 18 having a diameter of 10 mm. An Ag / AgCl microelectrode (φ = 0.1 mm) 31 coated with agar containing saturated KCl was provided on the coating film defect portion 18. The potential of the steel sheet base material 17 with respect to the electrode 31 was output to a computer via a buffer, and data was collected.
【0017】制御器30にAC100V電源を接続し、
パイロット陽極20の電圧が設定値10Vの一定になる
ことを確認した後に、塗装鋼板16を約30日間の暴露
テストにかけた。その結果、湿度が60%未満の状態で
は、主陽極15に印加されている電圧は、最小値10V
を示し、湿度が高くなる程、その電位が上昇し、降雨時
に13V前後に到達した。
A 100 VAC power supply is connected to the controller 30,
After confirming that the voltage of the pilot anode 20 was constant at the set value of 10 V, the coated steel plate 16 was subjected to an exposure test for about 30 days. As a result, when the humidity is less than 60%, the voltage applied to the main anode 15 has a minimum value of 10 V
The higher the humidity, the higher the potential, and reached about 13 V during rainfall.
【0018】さらに、塗膜欠陥部を、前述の位置に加え
て、主陽極15およびパイロット陽極20のそれぞれの
陽極と前記位置の塗膜欠陥部18との間にも形成して、
降雨時における主陽極15の印加電圧が最大の15Vに
達するようにした。
Further, in addition to the above-described positions, the coating defect portions are formed between the respective anodes of the main anode 15 and the pilot anode 20 and the coating defect portions 18 at the positions,
The voltage applied to the main anode 15 during rainfall reached a maximum of 15V.
【0019】この状態でも、塗膜欠陥部18の電位は、
−850mV前後の値を示しており、十分に防食が達成
できていることが判った。
Even in this state, the potential of the coating defect 18 is
The value around -850 mV was shown, indicating that the anticorrosion was sufficiently achieved.
【0020】さらに、主陽極15の近傍の塗膜17にも
過防食の兆候は見られず、主陽極15から塗膜17の欠
陥部18に流れる電流が充分に大きいため、主陽極15
の下部の絶縁接合体(特殊媒体)70表面の水膜におけ
る電圧降下によって、主陽極15近傍の塗膜部における
電圧が過防食を引き起こす電圧よりも低くなっているこ
とが推察できた。
Further, there is no sign of excessive corrosion prevention in the coating film 17 near the main anode 15, and the current flowing from the main anode 15 to the defective portion 18 of the coating film 17 is sufficiently large.
It can be guessed that the voltage drop in the water film on the surface of the insulating joint body (special medium) 70 below the lower portion causes the voltage in the coating portion near the main anode 15 to be lower than the voltage causing excessive corrosion protection.
【0021】すなわち、主陽極15から2.5〜3.0
m離れた位置の塗膜欠陥部18と主陽極15との間に他
の塗膜欠陥部を増やしていって、所要防食電流が増える
場合、従来の技術では、主陽極の電圧12Vが限界とな
り、塗膜欠陥部18の電位が防食電位まで低下しないこ
ととなるのに対し、本発明の方法および装置では、電流
所要量の増加とともに、(本テストでは15Vを最大値
としたが、)電圧が上昇し、そのために、塗膜欠陥部が
かなり増えても、最遠の欠陥部18の電位が充分低下し
て防食電位に達していることが確認された。このことか
ら、本発明によって、防食能が従来技術よりも優れた新
技術を確立することができた。
That is, from the main anode 15 to 2.5 to 3.0
In the case of increasing the required anticorrosion current by increasing other coating defect portions between the coating defect portion 18 and the main anode 15 at a distance of m, the voltage of the main anode is limited to 12 V in the conventional technology. In contrast, the potential of the coating defect 18 does not drop to the anticorrosion potential, whereas the method and apparatus of the present invention increase the current requirement and increase the voltage (although the maximum value was 15 V in this test). It has been confirmed that even when the number of defective coatings increases considerably, the potential of the farthest defective portion 18 has sufficiently decreased to reach the anticorrosion potential. From the above, according to the present invention, a new technology having a superior anticorrosion ability than the conventional technology could be established.
【0022】塗膜形成塗料と陰極防食法の組み合わせに
よる最も経済的な金属製構造物の防食を行う方法とし
て、下層は汎用の絶縁性塗料を塗布し、最上層には電気
抵抗の低い導電性の塗料を施した金属製構造物(塗装鋼
板)に、本発明による陰極防食法の設備を用いて、図2
に示したテストを行った。
As the most economical method of preventing corrosion of a metal structure by a combination of a coating film forming paint and a cathodic protection method, a general-purpose insulating paint is applied to a lower layer, and a conductive material having a low electric resistance is applied to a top layer. FIG. 2 shows a metal structure (painted steel plate) coated with the paint of FIG.
The tests shown in Table 1 were performed.
【0023】最上層の塗料として電気抵抗値0.2Ωc
mのものを使用して、主陽極15から5m離れた位置に
塗膜の人工欠陥部を設けて、制御器30に通電し、塗装
鋼板16の表面に散水して、塗膜欠陥部18の電位を測
定した。
Electric resistance of 0.2 Ωc as the top layer paint
The artificial defect portion of the coating film is provided at a position 5 m away from the main anode 15 by using a material having a thickness of 5 m and the controller 30 is energized to spray water on the surface of the coated steel plate 16. The potential was measured.
【0024】その電位は、−850〜−950mVの値
を示し、不活性領域内にあり、充分防食が果たされてい
ることが明らかとなった。
The potential showed a value of -850 to -950 mV, which was in the inactive region, and it was clarified that the anticorrosion was sufficiently achieved.
【0025】通常の絶縁性塗料を用いたカラー鋼板で
は、人工欠陥部が主陽極から2.5〜3.5m程度まで
しか防食電位に達しないのに対し、塗料と陰極防食の最
適な組み合わせによって、防食範囲を大幅に拡大できる
技術を確立することができた。
In the case of a color steel sheet using a normal insulating paint, the artificial defect reaches the corrosion protection potential only up to about 2.5 to 3.5 m from the main anode. In this way, we were able to establish a technology that could greatly expand the range of anticorrosion.
【0026】[0026]
【発明の実施の形態】以下、本発明の実施の形態を説明
するが、本発明は、これらの実施の形態に限定されるも
のではない。
DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these embodiments.
【0027】図3は、本発明にかかる金属製構造物の陰
極防食法を実現するのに好適な装置の回路図である。
FIG. 3 is a circuit diagram of an apparatus suitable for realizing the cathodic protection method for a metal structure according to the present invention.
【0028】本方法では、被防食体である塗装鋼板16
の塗膜17に欠陥部18があり、前記塗装面にアルミニ
ウム製などの陽極150が絶縁性両面接合体70により
接着されている。湿度が60%前後となる時、水膜19
が塗装鋼材16を覆い、それに大気汚染物質や海塩粒子
が溶け込んで、水膜19を構成する水は電解質水溶液と
なり、塗膜欠陥部分18に錆を発生させる条件が成立す
る。これに対し、本発明による制御器および陽極150
から最適の防食電流を、水膜19を介して塗膜欠陥部1
8に供給することにより、塗膜欠陥部18における発錆
を防止するものである。
In this method, the coated steel plate 16 to be protected is protected.
The coating 17 has a defective portion 18, and an anode 150 made of aluminum or the like is adhered to the painted surface by an insulating double-sided joint 70. When the humidity becomes around 60%, the water film 19
Covers the coated steel material 16, into which air pollutants and sea salt particles dissolve, the water constituting the water film 19 becomes an aqueous electrolyte solution, and the conditions for generating rust on the defective portion 18 of the coating film are satisfied. In contrast, the controller and anode 150 according to the present invention
From the coating film defect portion 1 through the water film 19.
8 prevents rusting at the coating defect 18.
【0029】図に示すように、AC100〜200V電
源の端子33から電気を導入し、ヒューズ34、サージ
電流吸収のバリスター35、トランス36を介して、A
C18〜20Vに落圧して、整流回路37によって直流
にする。コンデンサー38によって電圧変動を吸収し、
レギュレータ39によって直流17Vの電気を供給す
る。そして、コンデンサー40によって、DC17Vを
安定化する。
As shown in the figure, electricity is introduced from a terminal 33 of a 100 to 200 V AC power supply, and is supplied through a fuse 34, a surge current absorbing varistor 35, and a transformer 36.
The voltage is lowered to C18 to 20V, and is converted to DC by the rectifier circuit 37. Absorb the voltage fluctuation by the capacitor 38,
A regulator 39 supplies 17 V DC electricity. Then, DC17V is stabilized by the capacitor 40.
【0030】陽極150から水膜19を通して塗膜17
の欠陥部18から塗装鋼板16に流入する電流の大きさ
によって変化する抵抗器48の電圧降下を、オペアンプ
45で検出し、その値によって、トランジスター44の
エミッターから流出する電流の電圧を制御する。抵抗器
41、42、46、47、49、50およびコンデンサ
ー43は、系の安定した作動を補助する。トランジスタ
ー51、ツェナーダイオード53、抵抗器52、54
は、陽極150から流れ出る電流が一定値を越さないよ
うにする電流制限手段102を構成している。
The coating film 17 from the anode 150 through the water film 19
The voltage drop of the resistor 48, which varies depending on the magnitude of the current flowing from the defective portion 18 into the coated steel plate 16, is detected by the operational amplifier 45, and the voltage of the current flowing out of the emitter of the transistor 44 is controlled based on the detected value. The resistors 41, 42, 46, 47, 49, 50 and the condenser 43 assist in the stable operation of the system. Transistor 51, Zener diode 53, resistors 52, 54
Constitutes the current limiting means 102 for preventing the current flowing out of the anode 150 from exceeding a certain value.
【0031】前記電源端子33、ヒューズ34、バリス
ター35、トランス36、整流回路37、コンデンサー
38、レギュレータ39、およびコンデンサー40は、
一基の制御器30内に収納する。また、前記抵抗器41
および42、コンデンサー43、トランジスター44、
オペアンプ45、抵抗器46,47,48,49,およ
び50、トランジスター51、抵抗器52、ツェナーダ
イオード53、および抵抗器54は、陽極150に一体
的に組み込む。一基の制御器30は、一つあるいは複数
の陽極システムへ一定電圧の電流を供給する。
The power supply terminal 33, fuse 34, varistor 35, transformer 36, rectifier circuit 37, capacitor 38, regulator 39, and capacitor 40
It is stored in one controller 30. In addition, the resistor 41
And 42, a capacitor 43, a transistor 44,
The operational amplifier 45, the resistors 46, 47, 48, 49, and 50, the transistor 51, the resistor 52, the Zener diode 53, and the resistor 54 are integrated into the anode 150. One controller 30 supplies a constant voltage current to one or more anode systems.
【0032】図4に、前記陽極150の一例を示す。FIG. 4 shows an example of the anode 150.
【0033】図中、55は板状アルミニウム陽極であ
り、その上面に開口する凹部56中にトランジスター、
オペアンプ、ツェナーダイオード、抵抗器等を含む前記
電流制御手段102をはめ込み、その部分を硬質のエポ
キシ樹脂で固めた。
In the figure, reference numeral 55 denotes a plate-shaped aluminum anode, and a transistor,
The current control means 102 including an operational amplifier, a zener diode, a resistor and the like was fitted therein, and the portion was hardened with a hard epoxy resin.
【0034】前記電流制御手段102には、外部からの
リード線58が接続されている。59は制御器30から
のアノード配線を接続する圧着端子である。陽極55
は、塗装鋼板16の塗膜17に、両面接合体70を用い
て、貼り付ける。
An external lead wire 58 is connected to the current control means 102. Reference numeral 59 denotes a crimp terminal for connecting the anode wiring from the controller 30. Anode 55
Is attached to the coating film 17 of the coated steel plate 16 using the double-sided bonded body 70.
【0035】[0035]
【発明の効果】金属製構造物の表面塗装の塗膜には、目
には見えない無数のピンホールが開いている場合が多
い。また、砂埃、その他の大気中の環境因子により、経
時的に、塗膜に欠陥が生じる。このような状況下で、大
気中の湿度が60%を越すと、塗膜表面に水膜が形成さ
れるが、この表面の水膜中には大気中の海塩粒子等が溶
け込んで、水膜水は電解質水となる。この電解質水が前
記ピンホールや塗膜欠陥部を通して、金属の表面に接触
し、発錆の条件が整う。このときに、前記電解質水膜を
通して防食電流を流して、発錆を抑制するのが、陰極防
食法である。この陰極防食法において、本発明の方法
は、従来の方法と異なって、所要電流量の増大に応じて
陽極に印加する電圧を上昇させ、従来、過防食のために
不可能と考えられていた陽極から離れた領域にまで防食
電流を流すことができる。本発明では、防食対象である
金属製構造物の塗膜と陽極との間に介在する電気抵抗を
有する特殊媒体(電解質水膜)の特性の変動、および塗
膜欠陥部の大きさに応じて、防食電流、電圧を最適に制
御する。陽極の近傍の塗膜で過防食とならない最大電圧
を、電流が大きくなっても保持することにより、陽極を
出発点とする電気防食可能な領域を増大させることがで
きた。
As described above, in many cases, innumerable pinholes are invisible in the surface coating film of a metal structure. Further, due to dust and other environmental factors in the atmosphere, defects occur in the coating film over time. Under these circumstances, if the humidity in the atmosphere exceeds 60%, a water film is formed on the surface of the coating film. The membrane water becomes electrolyte water. The electrolyte water comes into contact with the surface of the metal through the pinholes and the coating defect, and the conditions for rusting are set. At this time, it is the cathodic protection method in which an anticorrosion current flows through the electrolyte water film to suppress rusting. In this cathodic protection method, the method of the present invention, unlike the conventional method, raises the voltage applied to the anode in accordance with an increase in the required current amount, and was conventionally considered impossible due to excessive corrosion protection. The anticorrosion current can flow to a region away from the anode. In the present invention, the characteristics of a special medium (electrolyte water film) having an electric resistance interposed between a coating film of a metal structure to be protected and an anode, and the size of a defective portion of the coating film are determined. Optimum control of anticorrosion current and voltage. By maintaining the maximum voltage at which the coating near the anode did not cause over-corrosion even when the current increased, it was possible to increase the area in which the anode could be used as a starting point for cathodic protection.
【0036】また、汎用の絶縁性塗料の下塗りを行った
上に、表面仕上げ塗装として導電性の特殊塗料を塗り、
さらに、そこに本発明による陰極防食法を適用すること
により、陽極を出発点とする電気防食領域を飛躍的に増
大させることができた。したがって、塗料の種類と本発
明による陰極防食法の電圧、電流の値の組み合わせによ
る最適化を図ることにより、経済性の高い金属製構造物
の防食法を確立できる。
In addition, after a general-purpose insulating paint is undercoated, a special conductive paint is applied as a surface finish coating,
Furthermore, by applying the cathodic protection method according to the present invention thereto, the cathodic protection region starting from the anode could be increased dramatically. Therefore, by optimizing the combination of the type of paint and the voltage and current values of the cathodic protection method according to the present invention, a highly economical method of protecting metal structures from corrosion can be established.
【図面の簡単な説明】[Brief description of the drawings]
【図1】本発明の金属製構造物の陰極防食装置の一例の
回路図である。
FIG. 1 is a circuit diagram of an example of a cathodic protection apparatus for a metal structure according to the present invention.
【図2】図1に示した装置の機能を測定するためのシス
テムの説明図である。
FIG. 2 is an explanatory diagram of a system for measuring the functions of the device shown in FIG.
【図3】本発明の金属製構造物の陰極防食装置の他の例
の回路図である。
FIG. 3 is a circuit diagram of another example of the cathodic protection device for a metal structure according to the present invention.
【図4】図3に示した装置の陰極の一例を示す斜視図で
ある。
FIG. 4 is a perspective view showing an example of a cathode of the device shown in FIG.
【符号の説明】 1、33 電源端子 2、34 ヒューズ 3、35 バリスター 4、36 トランス 5、37 整流回路 6、7、9、10、21、23、24、25、38、4
0、43 コンデンサー 8、22、39 レギュレータ 11、44、51 トランジスター 12、14、27、28、29 抵抗器 13、53 ツェナーダイオード 15 主陽極 16 塗装鋼板(金属製構造物) 17 塗膜 18 前記塗膜の欠陥部 19 塗装鋼板の表面に形成される水膜 20 パイロット陽極 26、45 オペアンプ 30 制御器 30a 制御器からのアノード線 30b 制御器からのカソード線 31 Ag/AgCl微小電極(φ=0.1mm) 32 塗装鋼板の母材 41、42、46、47、48、49、50、52、5
4 抵抗器 55 板状アルミニウム陽極 56 凹部 58 リード線 59 圧着端子 70 絶縁性両面接合体(電気抵抗を有する特殊な媒
体) 100 第1の電流制限手段 101 第2の電流制限手段 102電流制限手段 150 陽極
[Description of Signs] 1, 33 Power supply terminal 2, 34 Fuse 3, 35 Varistor 4, 36 Transformer 5, 37 Rectifier circuit 6, 7, 9, 10, 21, 23, 24, 25, 38, 4
0, 43 Capacitor 8, 22, 39 Regulator 11, 44, 51 Transistor 12, 14, 27, 28, 29 Resistor 13, 53 Zener diode 15 Main anode 16 Painted steel plate (metal structure) 17 Coating 18 Coating Defects in the film 19 Water film formed on the surface of the coated steel plate 20 Pilot anode 26, 45 Operational amplifier 30 Controller 30a Anode wire from controller 30b Cathode wire from controller 31 Ag / AgCl minute electrode (φ = 0. 1mm) 32 Base material of painted steel plate 41, 42, 46, 47, 48, 49, 50, 52, 5
Reference Signs List 4 resistor 55 plate-shaped aluminum anode 56 recess 58 lead wire 59 crimp terminal 70 insulating double-sided joint (special medium having electric resistance) 100 first current limiting means 101 second current limiting means 102 current limiting means 150 anode

Claims (9)

    【特許請求の範囲】[Claims]
  1. 【請求項1】 外部電源から金属製構造物に電流を通電
    させ、該金属製構造物の腐食を防止する陰極防食法であ
    って、 前記金属製構造物の塗膜上に主陽極とパイロット陽極と
    を取り付けるとともに、該金属製構造物の金属母材に陰
    極を取り付け、前記パイロット陽極から前記金属製構造
    物に所定の電圧を印加し、腐食防止を行う対象である前
    記金属製構造物の防食電流所要量の大きさを、前記金属
    製構造物の腐食環境の変動に応じて変化する前記パイロ
    ット陽極の電流値から読みとり、この電流値に連動して
    前記主陽極の印加電圧を上下させ、これにより前記金属
    製構造物の腐食環境に応じた最適の防食電流を供給する
    ことを特徴する金属製構造物の陰極防食法。
    1. A cathodic protection method for applying a current to a metal structure from an external power source to prevent corrosion of the metal structure, wherein a main anode and a pilot anode are provided on a coating film of the metal structure. And attaching a cathode to the metal base material of the metal structure, applying a predetermined voltage from the pilot anode to the metal structure, and preventing corrosion of the metal structure to be subjected to corrosion prevention. The magnitude of the required current is read from the current value of the pilot anode, which changes according to the change in the corrosive environment of the metal structure, and the voltage applied to the main anode is increased and decreased in conjunction with this current value. A cathodic protection method for a metal structure, the method comprising supplying an optimum anticorrosion current according to the corrosive environment of the metal structure.
  2. 【請求項2】 前記パイロット陽極と主陽極が1対1対
    応のみならず、一つのパイロット陽極を複数の主陽極と
    対応させたことを特徴とする請求項1に記載の陰極防食
    法。
    2. The cathodic protection method according to claim 1, wherein not only one pilot anode and one main anode correspond but also one pilot anode corresponds to a plurality of main anodes.
  3. 【請求項3】 前記パイロット陽極および主陽極を絶縁
    性両面接合体を介して防食対象である金属製構造物に取
    り付けることによって、前記金属製構造物の表面から前
    記各陽極に連続して水膜が形成され、前記金属製構造物
    の腐食条件が整った時に、前記陽極と、前記金属製構造
    物の金属母材に接続した前記陰極との間に、防食に最適
    な電流が流れるようにしたことを特徴とする請求項1ま
    たは2の陰極防食法。
    3. A water film is continuously provided from the surface of the metal structure to each of the anodes by attaching the pilot anode and the main anode to a metal structure to be protected from corrosion by a double-sided insulating body. Is formed, and when the corrosion conditions of the metal structure are adjusted, an optimal current for corrosion prevention flows between the anode and the cathode connected to the metal base material of the metal structure. The cathodic protection method according to claim 1 or 2, wherein:
  4. 【請求項4】 外部電源から金属製構造物に電流を通電
    させ、該金属製構造物の腐食を防止する陰極防食装置で
    あって、 前記金属製構造物の塗膜上に取り付ける主陽極とパイロ
    ット陽極と、 前記金属製構造物の金属母材に接続する陰極と、 前記パイロット陽極から前記金属製構造物に所定の電圧
    を印加し、腐食防止を行う対象である前記金属製構造物
    の防食電流所要量の大きさを、前記金属製構造物の腐食
    環境の変動に応じて変化する前記パイロット陽極の電流
    値から読みとり、この電流値に連動して前記主陽極の印
    加電圧を上下させ、これにより前記金属製構造物の腐食
    環境に応じた最適の防食電流を供給する電流制御手段
    と、を有することを特徴する金属製構造物の陰極防食装
    置。
    4. A cathodic protection device for applying a current to a metal structure from an external power source to prevent corrosion of the metal structure, comprising: a main anode and a pilot mounted on a coating film of the metal structure. An anode, a cathode connected to a metal base material of the metal structure, and a predetermined voltage applied from the pilot anode to the metal structure to prevent corrosion of the metal structure to be subjected to corrosion prevention. The magnitude of the required amount is read from the current value of the pilot anode that changes in accordance with the change in the corrosive environment of the metal structure, and the voltage applied to the main anode is increased or decreased in accordance with the current value, whereby A current control means for supplying an optimum anticorrosion current according to the corrosive environment of the metal structure; a cathodic protection device for a metal structure.
  5. 【請求項5】 前記パイロット陽極と主陽極が1対1対
    応のみならず、一つのパイロット陽極が複数の主陽極と
    対応させられていることを特徴とする請求項4に記載の
    陰極防食装置。
    5. The cathodic protection apparatus according to claim 4, wherein not only one pilot anode and one main anode correspond to each other, but one pilot anode corresponds to a plurality of main anodes.
  6. 【請求項6】 前記パイロット陽極および主陽極を前記
    金属製構造物の表面に取り付けるための絶縁性両面接合
    体を、さらに有し、該絶縁性両面接合体を介して防食対
    象である金属製構造物に前記各陽極を取り付けることに
    よって、前記金属製構造物の表面から前記各陽極に連続
    して水膜が形成され、前記金属製構造物の腐食条件が整
    った時に、前記陽極と、前記金属製構造物の金属母材に
    接続した前記陰極との間に、防食に最適な電流が流れる
    ようにしたことを特徴とする請求項4または5に記載の
    陰極防食装置。
    6. A metal structure which is further provided with an insulative double-sided joint for attaching the pilot anode and the main anode to a surface of the metal structure, and which is to be subjected to anticorrosion via the insulative double-sided joint. By attaching each of the anodes to an object, a water film is formed continuously from the surface of the metal structure to each of the anodes, and when the corrosion conditions of the metal structure are adjusted, the anode and the metal The cathodic protection device according to claim 4 or 5, wherein a current optimal for anticorrosion flows between the cathode connected to the metal base material of the structure.
  7. 【請求項7】 前記パイロット陽極および主陽極の機能
    を一体的に設けたことを特徴とする請求項4ないし6の
    いずれかに記載の陰極防食装置。
    7. The cathodic protection device according to claim 4, wherein the functions of the pilot anode and the main anode are integrally provided.
  8. 【請求項8】 前記電流制御手段は、トランジスター、
    ダイオード、オペアンプ、抵抗器、その他の電子部品よ
    りなることを特徴とする請求項4ないし7のいずれかに
    に記載の陰極防食装置。
    8. The current control means includes a transistor,
    The cathodic protection device according to any one of claims 4 to 7, comprising a diode, an operational amplifier, a resistor, and other electronic components.
  9. 【請求項9】 防食対象である金属製構造物の塗装を、
    下層は通常の絶縁性塗料とし、最上層を導電性塗料とす
    る組み合わせにより、行い、塗装を完了した前記金属製
    構造物に、前記請求項1ないし3のいずれかの陰極防食
    を適用することを特徴とする金属製構造物の陰極防食
    法。
    9. The coating of a metal structure to be subjected to anticorrosion,
    The lower layer is made of a normal insulating paint and the uppermost layer is made of a conductive paint, and the cathodic protection of any one of claims 1 to 3 is applied to the metal structure that has been coated. Characteristic cathodic protection of metal structures.
JP09318798A 1998-04-06 1998-04-06 Cathodic protection method and apparatus for metal structures Expired - Lifetime JP4148373B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
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Application Number Priority Date Filing Date Title
JP09318798A JP4148373B2 (en) 1998-04-06 1998-04-06 Cathodic protection method and apparatus for metal structures
TW88117247A TW477832B (en) 1998-04-06 1999-10-06 Cathodic corrosion reisting method for metallic structure, and device therefor

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Publication Number Publication Date
JPH11286793A true JPH11286793A (en) 1999-10-19
JP4148373B2 JP4148373B2 (en) 2008-09-10

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001025507A1 (en) * 1999-10-06 2001-04-12 Jonan Co., Ltd. Cathodic protection method and device for metal structure
KR100380113B1 (en) * 2000-05-20 2003-04-16 아키정보기술(주) A Corrosion Prediction System of Underground Metallic Structures and it's Analysis Method
KR100408868B1 (en) * 2001-02-14 2003-12-11 히데오 모리 A structure of an electrode in the cathodic corrosion protection system with an impressed current system
KR100897320B1 (en) 2001-06-08 2009-05-14 어플라이드 세미컨덕터, 인크. Semiconductive polymeric system, devices incorporating the same, and its use in controlling corrosion

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001025507A1 (en) * 1999-10-06 2001-04-12 Jonan Co., Ltd. Cathodic protection method and device for metal structure
US6506295B1 (en) 1999-10-06 2003-01-14 Jonan Co., Ltd. Cathodic protection method and device for metal structure
KR100380113B1 (en) * 2000-05-20 2003-04-16 아키정보기술(주) A Corrosion Prediction System of Underground Metallic Structures and it's Analysis Method
KR100408868B1 (en) * 2001-02-14 2003-12-11 히데오 모리 A structure of an electrode in the cathodic corrosion protection system with an impressed current system
KR100897320B1 (en) 2001-06-08 2009-05-14 어플라이드 세미컨덕터, 인크. Semiconductive polymeric system, devices incorporating the same, and its use in controlling corrosion

Also Published As

Publication number Publication date
JP4148373B2 (en) 2008-09-10
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