Atmospheric corrosion in energy infrastructure: understanding and strategies

Atmospheric corrosion in energy infrastructure is one of the most problematic and persistent issues in corrosion engineering. It generally occurs in oil pipelines, gas pipelines, storage tanks, and offshore platforms, causing considerable economic losses and operational risks (Uhlig & Revie, 2008).

The objective of this article is to provide a comprehensive overview of atmospheric corrosion in energy infrastructure, addressing its definition, main mechanisms, environmental factors that accelerate it, risk classification, and mitigation strategies. It also includes documented case studies from the industry, with the aim of providing the reader with a clear understanding of the problem and the solutions that can be applied in the real world.

What is atmospheric corrosion?

Atmospheric corrosion is defined as the electrochemical degradation of metallic materials exposed to the external environment (Uhlig & Revie, 2008). This phenomenon poses a silent challenge to energy infrastructure, affecting everything from oil and gas pipelines to storage tanks and offshore platforms.

Unlike internal corrosion, which depends on transported fluids, atmospheric corrosion depends directly on environmental factors such as humidity, temperature, salinity, industrial pollution, and ultraviolet radiation. Prolonged exposure to these conditions leads to loss of metal thickness, structural weakening, and eventually critical failures if adequate preventive strategies are not implemented (Bockris & Reddy, 2000).

Main mechanisms of atmospheric corrosion

Atmospheric corrosion mechanisms can be classified as uniform, pitting, galvanic, stress, and biological. Uniform corrosion is characterized by homogeneous material loss, making it easier to predict and mitigate using protective coatings and anti-corrosive paints. On the other hand, localized corrosion, such as pitting, creates deep cavities that quickly compromise structural integrity and are difficult to detect.

Galvanic corrosion occurs when two metals with different electrochemical potentials are in electrical contact and exposed to an electrolyte, while stress corrosion combines mechanical and chemical factors, weakening materials under stress. Finally, microbiologically influenced atmospheric corrosion represents an emerging risk, where biofilms and microorganisms accelerate surface degradation (Revie, 2011).

What factors influence atmospheric corrosion?

The types of factors linked to this type of corrosion are closely related to the atmospheric environment. Relative humidity is the determining factor in the rate of corrosion, as it promotes the formation of electrolytic films on the metal surface.

The presence of chlorides, particularly in coastal areas, accelerates localized corrosion, while industrial pollutants such as sulfur dioxide (SO₂) and nitrogen oxides (NOₓ) promote the formation of acids that attack metal surfaces.

Temperature influences both the kinetics of electrochemical reactions and the solubility of contaminants in the surface water film. Understanding these factors is essential for planning inspections and designing preventive maintenance programs (Fontana, 2005).

Risk of atmospheric corrosion in the energy industry

Risk classification allows corrective and preventive actions to be prioritized. Uniform corrosion is considered a medium risk, as it is easy to monitor using thickness loss tests. Localized and galvanic corrosion are usually classified as high risk due to their critical impact on pipes and tanks.

Stress corrosion and microbiological corrosion, although less frequent, are considered critical risks due to their ability to cause sudden and catastrophic failures (Revie & Uhlig, 2011). This classification guides the selection of mitigation strategies, optimizing operational availability and facility safety.

What mitigation and protection strategies are effective?

The most commonly used strategies include advanced coatings, cathodic protection, continuous monitoring, periodic inspections, and predictive maintenance.

• Polymer and metal coatings reduce the metal’s exposure to oxygen and electrolytes present in the environment.
• Cathodic protection, using sacrificial anodes or impressed current, is effective in buried or partially submerged structures, but requires constant monitoring to prevent secondary failures.
• The integration of monitoring technologies, such as humidity sensors and corrosion meters, allows for early detection of localized corrosion.
• Likewise, maintenance plans should prioritize critical areas exposed to high humidity, chlorides, and industrial contaminants (Baboian, 2005).

Atmospheric corrosion management in the energy industry

Effective management requires a multidisciplinary approach combining materials engineering, applied chemistry, structural mechanics, and asset management. It is recommended to develop corrosion maps, establish risk-based inspection programs, and maintain historical records of failures.

This integration allows informed decisions to be made about material replacement, structural reinforcement, and adjustments to maintenance programs. The implementation of digital asset information systems improves traceability and preventive maintenance planning, reducing costs and increasing the useful life of infrastructure (Revie & Uhlig, 2011).

Corrosion in land-based oil pipelines

An oil pipeline in the coastal region of the Gulf of Mexico experienced repeated failures due to atmospheric corrosion localized in sections exposed to high humidity and salt spray. Periodic ultrasonic inspections revealed deep pitting, which caused minor leaks. Mitigation was implemented by combining reinforced epoxy coatings, active cathodic protection, and continuous surface moisture monitoring, reducing reportable incidents by 85% over the next three years (Koch et al., 2002).

Microbiologically influenced atmospheric corrosion

In some onshore pipelines and tanks with condensation zones, biofilms were observed that accelerated the corrosion of carbon steel. Microbiological studies identified sulfuric acid-producing bacteria and mixed biofilms that caused rapid pitting. The strategy applied included periodic chemical treatment, controlled drainage of condensates, and biofilm-resistant coatings, which reduced the rate of thickness loss and extended the service life of the equipment (Little & Lee, 2007).

Conclusion

Atmospheric corrosion poses a silent but constant challenge to energy infrastructure. Understanding its mechanisms, environmental factors, and associated risks is essential for implementing effective mitigation strategies. The adoption of advanced coatings, cathodic protection, and systematic monitoring, together with comprehensive risk management, makes it possible to maintain operational safety, extend the useful life of assets, and reduce economic losses. The integration of these approaches is an essential practice for corrosion engineers and professionals in the energy sector. Case studies of atmospheric corrosion in energy infrastructure

References

1. Baboian, R. (2005). Corrosion tests and standards: Application and interpretation. ASTM International.
2. Bockris, J. O’M., & Reddy, A. K. N. (2000). Modern electrochemistry: Fundamentals of electrodics. Kluwer Academic Publishers.
3. Fontana, M. G. (2005). Corrosion engineering (3rd ed.). McGraw-Hill.
4. Revie, R. W. (2011). Uhlig’s corrosion handbook (3rd ed.). Wiley.
5. Revie, R. W., & Uhlig, H. H. (2011). Corrosion and corrosion control. Wiley.
6. Uhlig, H. H., & Revie, R. W. (2008). Corrosion and corrosion control (4th ed.). Wiley.
7. Koch, G. H., Brongers, M. P. H., Thompson, N. G., Virmani, Y. P., & Payer, J. H. (2002). Corrosion costs and preventive strategies in the United States. NACE International.
8. Fontana, M. G. (2005). Corrosion engineering (3rd ed.). McGraw-Hill.
9. Revie, R. W., & Uhlig, H. H. (2011). Corrosion and corrosion control. Wiley.
10. Little, B. J., & Lee, J. S. (2007). Microbiologically influenced corrosion. Wiley.