Cathodic Protection History

Cathodic Protection History

Cathodic protection was first discovered by a scientist named Sir Humphry Davy in the papers he had presented in the Royal Society in London back in the year 1824.

Thomas Edison tried impressed current cathodic protection on ships in 1890 to protect the hull but was not successful largely due to absence of appropriate source of direct current and suitable materials for development of anode.

CP is remarkable for what becomes of it by 1945 in the USA people commonly applied CP to the continuously growing oil/natural gas enterprise. In the United Kingdom, the use of CP was initiated in the 1950’s and cathodic protection company limited was initiated in this period signifying the beginning of the innovative usage of CP procedure in the region.

Cathodic Protection has become firmly develped for the vast range of submerged and earthen iron and steel constructions, together with reinforced concrete structures where it fulfills a sound method of corrosion protection.

As previously stated, the application of CP has been in existence since the nineteenth century, and it has been modified over and over. Here are some key milestones in the history of cathodic protection:Here are some key milestones in the history of cathodic protection:

Discovery of Galvanic Corrosion (1824): The history of cathodic protection can be subject to the discoverer of galvanic corrosion that was an Italian scientist Alessandro Volta. Volta noted that any two metals of different categories when joined and affixed to each other into an electrolyte solution, one metal would degrade while the other would be shielded. This phenomenon facilitated the development of electrode systems under the head of cathodic protection using sacrificial anodes.

Nobel Prize (1938): Viktor Gutmann, a Norwegian Scientist, who researched into the corrosion of iron within sea water and his efforts won him the Nobel Prize in Chemistry. The candidate’s work involved extension of knowledge about corrosion phenomena and Cathodic protection and methods of corrosion protection.

Invention of Sacrificial Anodes (Early 20th Century): While the idea of using sacrificial anodes, including zinc anodes and magnesium anodes, took root, in the early twentieth century. These anodes, when in contact with a metal structure, dissolve preferentially while leaving the structure intact; it is used in corrosion control . This meant a new advancement in the technology in cathodic protection technology had been made.

Growth in Marine Applications (1940s): In the period of Second World War, cathodic protection became widely used in the application related to sea industry especially regarding naval ships and hulls of the sea going vessels. Mainly it was perceived that cathodic protection could increase the shelf life of ships to carry out its task effectively and also reduced the maintenance cost of the ships to a great extent.

Development of ICCP Systems (1950s): As for impressed current cathodic protection (ICCP) systems, they emerged as another addition to the history of cathodic protection. ICCP systems incorporate outside sources of power like rectifiers in order to supply a regulated electrical current for protection purposes on the structures. It facilitated improved and versatile means of corrosion protection in so many sectors.

Advancements in Oil and Gas Industry (1960s): It spread its use for the protection of underground pipelines, storage tanks and offshore structures in the oil and industries. Cathodic protection was deemed necessary in minimizing failure particularly by corrosion and polluting the environment.

Standardization and Regulation: Later more standards and regulations on cathodic protection were established by global organizations that include NACE International that used to be known as the National Association of Corrosion Engineers. Cathodic protection systems required standards to set down requirements for design, installation, and maintenance.

Ongoing Research and Advancements: The use of cathodic protection also undergoes constant development in form of new materials and systems and more efficient, longer lasting as well as environmentally friendly systems are in the course of being developed.

Cathodic protection is commonly applied today in numerous fields to help protect metal structures like oil and gas, marine, water, and other structures used in infrastructure. Thus, Cathodic protection technology has emerged as one of the most vital tools for the service life of important structures and, thereby reducing corrosion cost and its effects on the environment.

Why cathodic protection is important

Cathodic protection is valued and needed for several reasons, mainly associated with protection and control of corrosion on the metallic structures, especially in environments that are aggressive. Here are the key reasons why cathodic protection is crucial:Here are the key reasons why cathodic protection is crucial:

Corrosion Prevention: DP is used mostly to mitigate or even cease the process of corrosion of metallic structures and systems. Corrosion is the undesirable changes in metal and its properties due to a reaction between the material and the environment and causes the materials to degrade slowly and become weaker until they fail. Cathodic protection is useful in ensuring that corrosion of such structures is reduced and hence their durability is preserved.

Cost Savings: One can carry out cathodic protection systems to help prevent further expenditure on corroded structures as opposed to replacing or repairing them. It increases the life cycle of the assets and thus it will require less frequency of repairant and maintenance which can be costly and time consuming.

Safety: The deterioration consequences as a result of corrosion in important structures like piping, bridges, and storage containers are dangerous to the public and the environment. Cathodic protection is a method used to protect such structures and therefore increases their safety through protection from corrosion.

Environmental Protection: This often results to the release of dangerous materials such as hazardous chemicals and pollutants which threatens the environment. Use of cathodic protection systems minimize cases of leakages and hence effect a reduction in polluting the environment. f

Regulatory Compliance: Most industries are bound by legal frameworks that dictate that the usage of cathodic protection to guard the structure’s integrity is necessary. Non-compliance to these regulations attracts legal and financial consequences hence the need to adhere to them.

Energy Efficiency: It can reach higher levels of force and friction that could greatly affect the efficiency of the pipelines and other systems leading to high energy consumption. Wanting to maintain and achieve their efficiency, cathodic protection is helpful in such systems.

Long-Term Asset Preservation: Anodes Cathodic protection systems are critical structures in protecting investments of many years in infrastructures like pipelines, underground storage tanks, bridges among others, of many years. Maintenance aids these assets to work as required and without incidence for the expected useful life of the asset.

Versatility: Cathodic protection can be used on most metallic structures commonly used in pipelines, storage tanks, offshore platforms, ship hulls and the like. It is a versatile material to be used in any environment or construction type.

Minimization of Downtime: The use of cathodic protection system can help decrease the frequency and time of maintenance shutdowns and repair. This reduces downtime especially in industries that require a chain process to run for very extended periods.

Preventive Maintenance: Cathodic protection is a preventive measure in maintenance and not a remedial one; hence is preferred to its ‘repair’ alternatives. This procedure guarantees continued protection of the pipelines and any probable problems are detected way ahead of time.

In conclusion, cathodic protection is instrumental in protection against corrosion, preservation of metallic structures, safety, meeting set standard, and reduced costs. They literally are a valuable technology for variety of industries as they serve to guard both one’s property and the nature as a whole.

What is cathodic protection on ships

Cathodic protection is a procedure applied for the purpose of protecting a ship from process of rusting. It functions on the ability to generate an electrical connection between the metallic structure of the ship and the water. This current makes the hull more cathodic or, in relation to the corrosion process, less susceptible to corrosion.

There are two main types of cathodic protection:There are two main types of cathodic protection:

• Sacrificial anode: It applies the use of a metal that is more reactive than the iron or steel which is being protected through the use of zinc or aluminum. An anode is connected to the outer surface of the hull of a ship. In the procedure of corrosion, the anode exacts electrons into the seawater. These electrons are conducted to the hull of the ship, which prevents the process of corrosion.
• Impressed current: Cathodic protection that applys an external source of electricity to complete an electrical circuit between the hull of the ship and the sea water. Commonly the power supply is a mode called a rectifier which steps the input AC power to DC power. The DC current is then passed through the hull of the ship by inserting electrodes in its body and the surrounding.

One of the most effective methods of fighting corrosion in ships is cathodic protection. Due to this characteristic it is employed by commercial and military ships operating throughout the world.

Benefits of cathodic protection on ships: 

• Exhibit the anti corrosive properties of painting the ship’s hull to protect the hull, this in turn can enhance the lifespan of the ship and ultimately decrease the costs of maintaining the ship.
• Prevents the corrosion of the ship internal structure inclusive of ballast tanks and piping systems.
• Reduces the probability of fissures and other failure modes resulting from the development of rancidness.
• Enhances the ship’s fuel economy since the bio fouling which is marine life formation on the hull of the ship increases the ship’s drag.

Disadvantages of cathodic protection on ships:

• Increase in the cost of installation and subsequent costs of the equipment.
• Can pose a great threat to life within marine habitats in the instance it’s not well designed and installed.

All in all, cathodic protection is an effective method of combating corrosion threats affecting ships and subsequently improving the life span of ships.

Cathodic protection on ships

A cathodic protection system goes to prevent or at least slow the corrosion of metal structures, normally by operating the metal as the cathode in an electrolyte cell. Here's how a cathodic protection system works:Here's how a cathodic protection system works:

Electrochemical Cell: It forms an electrochemical cell having an anode, a cathode, and an electrolyte, which is most often the environing earth or water.

Anode: Two main kinds of anodes can be employed in cathodic protection systems:.

Sacrificial Anodes: These are usually of zinc, aluminum or magnesium and they have lesser electrochemical potential as compared to the metal structure in question that they are meant to protect. Outfitting anodes will be attached to the structure and rather corrode than the protected material. They discharge electrons as they rust.

Impressed Current Anodes: More impressing type of current systems has an external power supply like the rectifier that sends a controlled electrical current to the structure. This current polarizes the structure’s surfaces, designating the cathode. Through the imposed current electrons are provided to the cathode in the case of the impressed current system.

Cathode: This structure to be protected is the cathode in this electrochemical cell. The cathode is the location where decrease response occurs. Electrons are brought to the cathode, thus, the emission of electrons at the anodic sites on the surface of the metal is hindered.

Electrolyte: The soil or water which is used to immerse the metal structure act as the electrolyte. It facilitates migration of ions and electrons from the anode to the cathode, thereby making up the path for the electrochemical circuit.

Corrosion Inhibition: Through negation of electrical potential on the surface of the metal, cathodic protection system slows down the entire oxidation (corrosion) process. Therefore, the metal structure which is used as the cathode does not surrender electrons to the anodic reactions, which promote corrosion. Otherwise, it is supplemented with electrons with the use of the sacrificial anodes or impressed current, thus, excluding the possibility of rust and corrosion formation.

Cathodic protection ensures that a specific electrical potential is maintained on the surface of the metal and therefore it becomes important for the system to be working well. This potential depends on the nature, number and location of the anodes and the current fed into the impressed current systems. The main consequence of the protective effect is regular monitoring and maintenance of the work of the system, providing the preservation of the corrosion protection of the metal structure.

It is applied in the industries like pipelines & storage tanks buried, ship hulls, bridges & any other structure that is more exposed to corrosive environments. It is probably one of the best ways to increase the service life of such structures not mentioning the expensive consequences of both corrosion and its repair.

How cathodic protection works to prevent rusting

Cathodic protection is a method of controlling the electrochemical process responsible for rusting or corrosion of structures made of metal. It operates such that the metal (usually steel) is made to act as the cathode in an electrochemical cell; thus, the anodic process (oxidation or corrosion) is slowed downs. Here's how cathodic protection prevents rusting:Here's how cathodic protection prevents rusting:

Basic Principle: In general, rusting or, also known as corrosion, is the gradual reaction of a metal with moisture and oxygen on the surface. They are; In presence of these species, the metal experience oxidation reaction and forms rust – iron oxide. This is represented as:

Metal (e. g. , iron) → Metal ions (e. g. , iron ions) + Electrons

During this step, the metal surrenders its electrons resulting in corrosion.

Cathode and Anode: The basic and most important requirements of a corrosion cell are: It consists of the anode and the cathode. The anode is presupposed to be the area of the corrosion-oxidation process during which the metal in question is turned into metal ions and electron release occurs. It is on the cathode where reduction reactions typically take place and these are reactions that use electrons. As mentioned earlier attenuating the flow of electrons in the varios from the anode to the cathode can restrain the corrosion process.

Application of Cathodic Protection: Cathodic protection entails causing a direct electric current onto the metal structure that requires protection. There are two primary methods for cathodic protection:There are two primary methods for cathodic protection:

a. Sacrificial Anodes: In this method, ‘sacrificial anodes’,—parts of metal which has a lower ‘electrochemical potential’ than that of the parent metal; for example zinc or aluminum are connected to the structure to be protected. These anodes give up their own metal in preference to the protected metal. While the sacrificial anodes erode, they liberate the electrons which in turn, neutralise the oxidation otherwise known as rusting of the steel protected.

b. Impressed Current Cathodic Protection (ICCP): ICCP systems, that have to be supplied and controlled, include the use of an external power source like rectifier. This current polarizes the structure’s surface, thereby becoming a cathode. The electrons provided by the ICCP system counteract the metal’s corrosion by denying further release of electrons at the anodic zones.

Inhibition of Rusting: Thus, cathodic protection has the effect of preventing the oxidation process by ensuring that the company retains a negative electrical potential on the surface of the metal. This means that former cathodic metal structure will not relinquish electrons to pro-anodic reactions causing rusting. However, the electrons are provided by the cathodic protection system, which avoids rust build up on the structure.

Cathodic protection is widely applied in many fields to protect pipelines and other structures buried into the ground, storage tanks, ships’ hulls and other metal structures against corrosion. This method is widely used and provides accurate outcomes in increasing the lifetime of such structures and cutting the expenses on maintenance of corrosion damage.

What is cathodic protection in chemistry

In chemistry, cathodic protection is a strategy applied on metals to secure it against corrosion while making it the cathode of the electrochemical cell. This is achieved by joining the metal to be protected to a metal which is more reactive, this is referred to as an anode. The anode dissolves while the metal to be protected is not affected but remains being protected.

This process is based on the principle of electrochemistry where metals with low oxidation potential (comparatively active metals will corrode before metals with high oxidation potential (Innocuous metals).

For instance if iron is joined to zinc it will the zinc that rust and not the iron. This is because zinc has a lower oxidation potential that iron thus it will corrode in a solution containing dissolved iron.

Cathodic protection is one of the best techniques that can be used for the protection of metals from corroding. That’s why it is successfully implemented in a number of spheres, such as oil and gas, petrochemical, power generation and marine.

Here are some examples of cathodic protection in chemistry:Here are some examples of cathodic protection in chemistry:

• Galvanized steel: Zinc is added on steel material to help it be shielded against corrosion.
• Sacrificial anodes: Sacrificial anodes such as zinc or aluminum are used and fixed on the ship and any other metallic structures which are susceptible to corrosion in seawater.
• Impressed current cathodic protection: DC current is passed through a metal structure through a sequence of electrodes in order to prevent it from rusting.

CP is widely used as a good anode to protect the metals from corrosion and increase the durability of the metal assets. It is employed in numerous applications such as; protection of ship and pipelines and even in the protection of structures of buildings.

How cathodic protection system works

A cathodic protection system works by using electrochemical principles to prevent or significantly reduce the corrosion of metal structures, typically by making the metal the cathode in an electrochemical cell. Here's how a cathodic protection system works:

Electrochemical Cell: The system creates an electrochemical cell that consists of three key elements: an anode, a cathode, and an electrolyte (usually the surrounding soil or water).

Anode: There are two primary types of anodes used in cathodic protection systems:

Sacrificial Anodes: These are typically made of metals like zinc, aluminum, or magnesium, which have a more negative electrochemical potential compared to the metal structure to be protected. Sacrificial anodes are connected to the structure, and they preferentially corrode instead of the protected metal. As they corrode, they release electrons.

Impressed Current Anodes: In impressed current systems, an external power source, such as a rectifier, supplies a controlled electrical current to the structure. This current polarizes the structure's surface, making it the cathode. Electrons are supplied through the impressed current system to the cathode.

Cathode: The metal structure to be protected is the cathode in this electrochemical cell. The cathode is the site where reduction reactions occur. Electrons are supplied to the cathode, which prevents the release of electrons at the anodic sites on the metal surface.

Electrolyte: The soil or water in which the metal structure is immersed serves as the electrolyte. It allows the transfer of ions and electrons between the anode and cathode, completing the electrochemical circuit.

Corrosion Inhibition: By maintaining a negative electrical potential on the metal surface, the cathodic protection system inhibits the oxidation (corrosion) process. As a result, the metal structure, now the cathode, does not give up electrons to the anodic reactions that cause corrosion. Instead, electrons are supplied through either sacrificial anodes or impressed current, preventing the formation of rust and corrosion.

The key to a successful cathodic protection system is maintaining the appropriate electrical potential on the metal surface. This potential is determined by factors such as the type and number of anodes, their positioning, and the electrical current supplied in impressed current systems. Regular monitoring and maintenance of the system are essential to ensure that the protective potential is sustained and that the metal structure remains corrosion-free.

Cathodic protection systems are used in various industries to protect buried pipelines, storage tanks, ship hulls, bridges, and other metal structures exposed to corrosive environments. They are a highly effective method for extending the service life of these structures and reducing the costly impact of corrosion-related damage and maintenance.

Cathodic protection principle

The main aspects of cathodic protection are derived from the basic concepts of the electrochemical reactions that take place during corrosion. It entails coming up with an electrochemical cell in which the metal structure to be protected is the cathode in such a manner that the process of corrosion of the metal is either arrested or severely curbed. Here are the key principles of cathodic protection:Here are the key principles of cathodic protection:

Electrochemical Cell: Corrosion is the process wherein electrons as well as ions are transferred, thus, it can be described as an electrochemical process. Cathodic protection systems create an electrochemical cell with the following components:Cathodic protection systems create an electrochemical cell with the following components:

• Anode: This is anytime the sacrificial anode or the location from where the electrical current source is originating from. In sacrificial steel anode systems the anode is of steels with less electrochemical potential than the structure which is to be protected. In impressed current systems the power source is connected to the anode which is located externally.
• Cathode: The metal structure to be protected is cathode in the cell they are known to be built mainly from the following metals.
• Electrolyte: Thus, the electrolytes in the system are represented by the surrounding environment which can be soil, water, or concrete, allowing the circulation of ions and electrons between the anode and the cathode.

Corrosion Process: Corrosion entails the reduction of the metal through the formation of metal ions, and the production of electrons:

Metal (e. g. , iron) → Metal ions (e. g. , iron ions) + E –

They reactions also occur at the anodic sites on the metal surface.

Cathodic Protection Mechanism: The functioning of the cathodic protection system is based on the means of putting the metal structure into a negative electrochemical potential called cathodic potential. This negative potential makes the metal to be the cathode in example electrochemical cell, where reduction reactions happen, and hence, use electrons. The electrons are provided to the cathode to thwart their emission at the anodic sites. Therefore, the metal structure is shield from further oxidation and corrosion is prevented.

Types of Cathodic Protection:

• Sacrificial Anodes: In this method, Septic anodes like zinc or aluminum are fixed on the structure that is to be protected. These anodes dissolve away at the structure instead of the protected metal and supply the right amount of electrons for cathodic protection.
• Impressed Current Cathodic Protection (ICCP): ICCP systems employ an external power such as rectifier to supply a controlled electrical current on the structure. This current reverses the metal structure and makes the structure of the cathode while at the same time reducing corrosion.
• Maintenance and Monitoring: It is important that proper cathodic potential is kept by the cathodic protection system and to achieve this right cathodic potential, there must be intermittent control and maintenance of the cathodic protection system. Sacrificial anodes may be corroded and hence would need to be replaced, while impressed current systems would require changes to the amount of current supplied to maintain the protection.

The general principle comprised in cathodic protection is to direct the possibilities of the electrochemical reactions on the metal’s surface by making the metal structure the cathode and supplying the necessary electrons to halt electrochemistry. This method is very efficient when it comes to the protection and even an attempt to increase the durability of metallic structures that are subjected to corrosion.

Where is cathodic protection used

Cathodic protection is used to protect a wide range of metallic structures in various environments, including:Cathodic protection is used to protect a wide range of metallic structures in various environments, including:

• Pipelines: Cathodic protection is used as an anticorrosion technique in pipelines; be it the buried pipelines or the ones that are submerged in water. Thus, pipelines transport oil, gas, water, and chemicals among others as some of their services. Leakage of pipes due to corrosion affects them and many cost consequences and at times could have negative impacts to the environment.
• Storage tanks: Cathodic protection is also used to protect Storage tanks also from the effects of corrosion. Some of the content that storage tanks are used to hold consist of oil, gas, water, and chemicals. Leaking and tank failures which results from corrosion of storage tanks bring in high costs, and also danger.
• Ships: Cathodic protection is applied to prevent corrosion on the ships’ hull, and other parts of the ship, including internal structures. Ship hulls are in contact with water and especially seawater which is highly corrosive. Internal systems like ballast tanks and piping systems are also prone to attacks by the corrosive environment. In general, corrosion of ships has effects such as leaks, structural failures, and even creation of fire.
• Offshore oil platforms: Coating of steel and cathodic protection is used to prevent corrosion to offshore oil platforms. Platforms are situated in sea environment that is very corrosive because of impact with the sea water. Rust on the offshore structures can cause the structures to collapse, leakages and even burst into flames.
• Rebar in concrete: Cathodic protection the same way is used to protect the rebar in concrete from corrosion. Rebar is steel that is imbedded into concrete to prevent the material from cracking from its own weight. The formation of rust on the surface of rebar can create cracks and chucks on the surface of the concrete and therefore reduce the span of the structure.

In addition to these specific examples, cathodic protection is used to protect a wide variety of other metallic structures, including:In addition to these specific examples, cathodic protection is used to protect a wide variety of other metallic structures, including:

• Heat exchangers
• Boilers
• Condensers
• Bridges
• Pier pilings
• Marine vessels
• Aircraft
• Automotive parts
• Medical devices

Cathodic protection is one of the most efficient methods of protection corrosion of metals and longevity of their use. This smart material is applied in a large number of fields including the protection of essential structures and articles for daily use.

Which metals provide cathodic protection to iron

Several metals can be used as sacrificial anodes to provide cathodic protection to iron and steel structures. These sacrificial anodes are selected based on their electrochemical potential, where they have a more negative potential than the iron or steel they are protecting. This means that they will preferentially corrode, sacrificing themselves to protect the iron or steel. Common sacrificial anode materials for cathodic protection of iron and steel include:

Zinc (Zn): Zinc is one of the most commonly used sacrificial anode materials. It has a more negative electrochemical potential than iron, making it an effective sacrificial anode. Zinc anodes are widely used in applications like marine environments to protect ship hulls and other submerged steel structures.

Aluminum (Al): Aluminum anodes are another popular choice for cathodic protection. They are often used in a variety of applications, including underground pipelines and storage tanks. Aluminum has a lower potential than steel and can effectively protect it from corrosion.

Magnesium (Mg): Magnesium is used in some cathodic protection applications, especially in environments with higher resistivity, such as in soils. Magnesium anodes have a strong negative potential and are often used in buried pipelines and tanks.

Galvanized Zinc (Galvanic Zinc): Galvanized zinc coatings on steel structures can act as sacrificial anodes and provide cathodic protection. The zinc coating corrodes in preference to the underlying steel.

The choice of sacrificial anode material depends on the specific application, environmental conditions, and the potential difference between the anode and the protected structure. Proper selection and maintenance of sacrificial anodes are essential to ensure effective cathodic protection and extend the service life of the iron or steel components. Sacrificial anodes need to be periodically inspected and replaced as they corrode, ensuring that they continue to provide adequate protection.

What is cathodic and anodic protection

The two techniques of electrochemical corrosion control are known as cathodic protection and anodic protection.

Cathodic protection is actually the technique of converting an engineering material into the Cathode in an electrochemical system. This is done by connecting the metal to a more active metal which takes the role of the anode. The anode thus corrodes rather than the metal which is intended to be protected and gains the protection.

Anodic protection is to offer the metal to be protected as an anode in the electrochemical cell and submit a potential to it to be constant on its passive status. The passive state is a very thin layer of oxide over the metal which protects the metal from further corrosion.

Differences between cathodic protection and anodic protection:

• With cathodic protection, you can protect virtually any metal, but anodic protection can only protect few metals like the stainless steel and titanium.
• The control of cathodic protection is inexpensive when installing and consuming materials and energy while anodic protection control is slightly expensive.
• Anodic protection is not commonly applied as much as cathodic protection.

Applications of cathodic protection and anodic protection:

• Cathodic protection is used extensively for pipelines, oil and gas storage tanks, ships, offshore oil installation and rebar in concrete.
• Anodic protection is a method of corrosion control applied in the chemical and process industries on the equipment, made of stainless steel and titanium.

Advantages and disadvantages of cathodic protection and anodic protection:

Cathodic protection:

• Advantages:
  • Effective for protecting any metal.
  • Relatively inexpensive to install and maintain.
• Disadvantages:
  • Can be harmful to marine life if not properly designed and installed.

Anodic protection:

• Advantages:
  • Effective for protecting stainless steel and titanium.
  • Can be used in aggressive environments where cathodic protection is not effective.
• Disadvantages:
  • More expensive to install and maintain than cathodic protection.
  • Can be difficult to control and maintain.

Comparing the two techniques of protection, cathodic protection can be seen as being more generalized and budget friendly when compared to anodic protection. But, anodic protection is one of the most effective and widely used technique to provide protection to stainless steel and titanium equipment used in aggressive surroundings.

what is cathodic protection

Cathodic protection is an electrochemical procedure applied in a way that prevent or significantly decreases the process of corrosion of metal structures including pipelines, storage tanks, bridges and ships through the management of electrochemical reactions that results in corrosion. The idea of cathodic protection is thus founded on the fact that the protected metal structure becomes the cathode of the electro chemical cell thereby preventing anodic or the corrosion reaction. Here's how cathodic protection works:Here's how cathodic protection works:

Basic Principle: Metal degradation particularly of steel occurs due to exposure of the metals to moisture, oxygen and other corrosive elements. Under these conditions, the metal corrodes through oxidation and migrates away; simultaneously, metal ions and electrons are released and therefore build rust.

Electrochemical Cell: The protection of cathodic serves an electrochemical cell comprising of three main factors:

• Anode: The anode is usually a sacrificial anode which is anode of lower electrochemical series than the structure requiring protection. In impressed current systems the anode is an external power source.
• Cathode: The metal structure to be protected becomes the Cathode of the electro chemical cell.
• Electrolyte: Outside surrounding like the soil, water, or concrete becomes the electrolyte through which ions and electrons from the two poles anode and cathode move.

Inhibition of Corrosion: Cathodic protection in an efficient way prevents the oxidation that is also known as corrosion because the outermost surface of the metal structure is given a negative electrical charge. In the anodic reactions which cause corrosion the metal structure of the positive electrode; now the cathode does not surrender electrons. It is transferred by the cathodic protection system whereas the electrons are supplied to the structure and thus avoiding the formation of rust and other forms of corrosion.

The technique of cathodic protection is employed in many fields to protect structures from corrosion related challenges in metals. There are two primary methods for cathodic protection:There are two primary methods for cathodic protection:

Sacrificial Anodes: These are sacrificial metals and they include zinc, aluminium or magnesium that are attached to the structure. Sacrificial anodes corrode at the required areas instead of the protected metal and thus supplies electrons while negating the metal corrosion.

Impressed Current Cathodic Protection (ICCP): Some of the most used ICCP systems rely in an independent power source such as a rectifier to source a controlled electrical current for the structure. This current polarizes the structure’s surface, thus becoming the cathode and hence minimizing corrosion.

Cathodic protection is among the most efficient ways of providing protection to the infrastructures which are potentially vulnerable to the corrosive by increasing the service life of metallic structure as well as decreasing the cost of maintenance and repair. It is crucial to note that, similar to any other monitoring protection device, cathodic protection requires to be checked and often maintained in order to continue providing protection.

How long does cathodic protection last

The useful life of any cathodic protection system is again a function of several factors, specific system type, environment and the quality of workmanship. At the same time, cathodic protection systems are smooth and well-designed as well as properly installed are expected to have a lifespan of up to 30 years.

Here are some factors that can affect the lifespan of a cathodic protection system:Here are some factors that can affect the lifespan of a cathodic protection system:

• Type of system: Each of the impressed current cathodic protection technologies is expected to have a lower useful life compared to the cathodic protection through sacrificial anode.
• Environment: Protection anodes for cathodic protection systems located in the aggressive milieu like seawater or chemical plants would be required more often than those from other less aggressive environment.
• Quality of installation: The cathodic protection system installations that are improperly conducted have high chances of failure in the near future.

Cathodic protection systems should be checked and audited from time to time to determine if they are functioning optimally and for elongation of their useful life.

Here are some tips for extending the lifespan of a cathodic protection system:Here are some tips for extending the lifespan of a cathodic protection system:

• Check the system for some debris or some forms of damage from time to time.
• Take the system for testing at least once a week for it to be ascertained whether it is working as it should be.
• Sacrificial anodes help protect the hull of a vessel from premature corrosion yet they eventually wear out as they are gradually consumed in the process of acting as anodic protection for the ship’s exterior surface and hence, replacement of sacrificial anodes is required as soon as they are established to be worn out.
• The impressed current power supply and the electrodes used should also be preserved.

If all these tips are practiced the cathodic protection system will longer offer protection to your metal structures.