Cathodic protection is an effective method that involves polarizing the metal to a state of immunity to corrosion. Corrosion of structural steel has been proven to stop when its potential reaches -800 mV, measured with a silver/silver chloride (Ag/AgCl) reference electrode, ideal for marine environments.
The most commonly used criteria for cathodic protection of steel structures include:
- Application of a polarization of -850 mV vs. Cu/CuSO₄
- 2. Polarized potential (off potential) of -850 mV vs. Cu/CuSO₄
- 1. Protection potential of -950 mV vs. Cu/CuSO₄ under anaerobic conditions with sulfate-reducing bacteria.
- 3. 100 mV polarization.
These values are established with reference to the Cu/CuSO₄ electrode and may vary depending on the electrode used, as shown in specialized tables.
Protection methods
Various strategies are employed to prevent corrosion, including the selection of suitable materials, the application of coatings, the use of inhibitors, and environmental control. However, Zineti has used a highly effective method for nearly 50 years: cathodic protection.
Cathodic protection
This method converts the entire metal surface into a cathode by applying an external electric current, preventing its deterioration. Two main approaches can be used:
1. Cathodic protection by sacrificial anode
A more anodic metal is connected to the structure to be protected, generating a galvanic cell where the anode corrodes instead of the cathode, preserving it.
2. Impressed current cathodic protection
An external electric current is applied by a rectifier to maintain the potential of the protected metal within the optimal immunity ranges.
Conclusion:
Cathodic protection is a key technique for safeguarding metallic structures from corrosive effects, extending their lifespan and reducing maintenance costs. Having an adequate and efficient system is essential to ensure the integrity of assets over time.
At Zineti, we specialize in offering advanced and customized cathodic protection solutions. With our experience and cutting-edge technology, we provide design, installation, and maintenance services to ensure maximum protection for your equipment and structures. As your trusted provider, we are committed to solving any corrosion-related challenge and ensuring the durability of your facilities.
If you need a reliable and effective cathodic protection solution, Zineti is here to help you. Don’t hesitate to contact us to learn more about how we can optimize the protection of your assets.