Impressed current cathodic protection ICCP

Coatings combined with impressed current cathodic protection (ICCP) are the most common means for the protection of shipboard. They interact with each other to protect shipboard. Coatings provide primary corrosion protection by isolating the hull metal from the seawater, while ICCP provides secondary corrosion protection in those areas where the paint is damaged or degraded. The protective effect is directly related to the ICCP configurations an incorrectly designed ICCP system would not only influence the protective effect but also... 

Cathodic protection is probably the most important of all approaches to corrosion control. Using an externally applied electric current, corrosion is reduced essentially to zero. A metal surface that is cathodically protected can be maintained in a corrosive environment without deterioration for an indefinite time. There are two types of cathodic protection impressed current cathodic protection (ICCP) and sacrificial anode cathodic protection (SACP), also known as galvanic cathodic protection. 

Aside from the use of linings, other corrosion protection techniques include cathodic protection and corrosion inhibitors. Impressed Current Cathodic Protection (ICCP) technology is attractive because it avoids the use of expensive alloys. The Electric Power Research Institute (EPRI) has developed a system that allows cathodic protection to be applied to duct walls having thin films of condensate, rather than immersed in a liquid [22]. EPRI also has evaluated the performance of several inhibitors on the corrosion behavior... 

Figure 8.1 shows the general diagram for protecting a stmcture from corrosion. The useful techniques for protecting metalUc stmctures can be solely applied or coupled with other technique, such as coating supplemented with impressed current cathodic protection (ICCP). 

The silver-silver chloride electrode simplicity of fabrication and fundamental ruggedness makes it a good candidate for many industrial applications where the electrochemical potential has to be measured or controlled. An important industrial example where this half-cell has become indispensable is to provide a measure of applied potential during the impressed current cathodic protection (ICCP) of sea-going ships. 

Cathodic protection is widely used on small to extremely large structures to protect metals and particularly steel against corrosion. This can often be accomplished by using a protective current that is either generated by a power supply in what is called impressed current cathodic protection (ICCP) or by using another metal that corrodes more readily than the metal being protected and therefore is sacrificed is the process. Chapter 13 provides a much detailed discussion of this important technique. 

When an impressed current cathodic protection (ICCP) system is in full operation there is a high possibility for oxygen to be produced at the anode, and in nearly all cells, hydrogen is formed at the cathode. If chloride ions are present, chlorine gas may be formed at the anode. This generation of gas, either oxygen or chlorine, at the anode is not nearly as likely to occur in a natural corroding cell as it is when an ICCP system is used, particularly when inert anodes are used. 

Using an impressed current cathodic protection (ICCP) provided by an external current source (Fig. 13.3). 

Impressed current cathodic protection (ICCP) and sacrificial anode cathodic protection (SACP) systems were designed... 

With the ICCP system shown in Fig. 13.10, the groundbed anodes are not really providing the driving power. Instead, some external source of direct electric current is connected (or impressed) between the structure to be protected and the groundbed anodes. The positive terminal of the power source is connected to the groundbed, which is then forced to discharge as much CP current as is desirable. If a mistake is made and the positive terminal is connected erroneously to the structure to be protected, the structure will become an anode instead of a cathode and will corrode actively. 

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