Corrosion is an often overlooked but essential part of the engineering process. It affects many lifesaving products, from planes to bridges, and so it must be managed correctly. One way to manage corrosion is through cathodic protection (CP). The purpose of CP is to control the rate of corrosion by applying a direct current to metallic components. This current creates a protective film on the surface that slows down or stops further corrosion.
Cathodic protection works by creating a cathode at the point where you want to protect against corrosion. This is done by connecting a sacrificial anode made of zinc, magnesium, or aluminum directly to the metal surface that needs protection. When electricity passes through this anode, it releases electrons into the surrounding environment and creates a cathode in the process.
The resulting reaction causes metal ions (corrosion) to be attracted away from the protected area and toward the sacrificial anode instead. This reduces corrosion over time and helps prevent further damage from occurring. The process also works in reverse for anodes—the metal ions are drawn away from them instead, which can help stop existing corrosion from spreading further. A NACE certified coating inspector we spoke to said that applying cathodic protection is one of the most effective ways to protect metal structures from corrosion. Their contact information can be found here.
An anode is similar to a sacrificial anode but with a different purpose. This type of protection works by providing current directly to the metal surface that needs protection, rather than using electrons from a sacrificial anode. This prevents the formation of galvanic cells (corrosion cells) on the surface and helps stop existing corrosion from spreading further. Indeed, this has been shown in a study by the US Naval Research Laboratory to be more effective than cathodic protection in some cases. This study also showed that anodic protection can improve the service life of steel structures and reduce maintenance costs.
So, in more laments terms, anodic protection works similarly to cathodic protection except that it uses an electric current as opposed to a direct current. Instead of using sacrificial anodes like with cathodic protection, anodes are placed at strategic points around the object being protected and connected via insulated wires to a power source. When electricity flows through these wires it creates an electrical potential difference between different points on the object being protected, thus reducing or eliminating any potential for galvanic corrosion effects.
The result is that any metal ions present in the environment are attracted away from those areas where they could potentially cause damage and towards those areas where they will be neutralized or even beneficial in some cases. By doing this, anodic protection helps keep your equipment safe and free from corrosive elements while still allowing you to use them in harsh environments without fear of damage due to galvanic corrosion effects.
Another important corrosion management tool is corrosion monitoring. This involves regularly measuring and evaluating factors such as pH levels, temperature, humidity, and more in order to detect any signs of corrosion early on. If a problem is detected, it can then be addressed quickly in order to prevent further damage. Corrosion monitoring can also be used to track the effectiveness of corrosion management strategies over time, allowing engineers to make any necessary adjustments or improvements.
It is estimated that by the year 2030, corrosion will cost the global economy around $4.5 trillion, so it is important to take proactive steps to prevent and manage corrosion before it can cause significant problems. The use of cathodic protection, anodic protection, and corrosion monitoring are all effective tools for combating corrosion in a variety of different scenarios. Utilizing these strategies can help ensure that your equipment stays safe and free from corrosive elements while still allowing you to use them in harsh environments without fear of damage due to galvanic corrosion effects.
In conclusion, when it comes to protecting against corrosion, both cathodic and anodic protection have their own benefits that make them viable options. Both strategies employ specialized methods depending on factors such as material composition, location, climate conditions, etc., but ultimately their goal is always the same: keeping your assets safe for longer periods of time by preventing damaging corrosive elements from affecting them negatively! Ultimately choosing one strategy over another depends on several factors such as budget constraints and environmental conditions but regardless of which one you choose both provide excellent options for keeping your assets safe against corrosive elements! For more on the subject visit the Electrochemical Society website here: https://knowledge.electrochem.org/encycl/art-c06-cathodic.htm