Carbon Dioxide Corrosion
CO2 corrosion is a form of uniform corrosion of metals in aqueous media caused by dissolved carbon dioxide. It forms porous iron carbonate scales and leads to material loss.
Physicochemical Mechanism of Action
Carbon dioxide (CO2) dissolves in water and forms carbonic acid (H2CO3). This reacts with iron (Fe) to form iron carbonate (FeCO3). This process causes chemical removal of the metal.
Metallurgical Relevance & Risks in Welding
CO2 corrosion can occur in aqueous environments, such as cooling water or hot water systems. It leads to a porous and corroded metal structure, reducing mechanical strength and component life. In the welding shop, it can contaminate the weld pool and cause porosity in the weld.
Shop Practice & Action Guidelines
To prevent CO2 corrosion, clean metals thoroughly before welding. Use proper deoxidation in the weld pool and ensure a clean welding process. In aqueous environments, regularly clean the system and monitor the water pH.