What is the primary common cause of atmospheric corrosion?

The primary cause of atmospheric corrosion is the presence of moisture and oxygen. These two elements are essential for the electrochemical reactions that lead to corrosion. When moisture, such as rain or humidity, comes into contact with metal surfaces, it creates an electrolyte solution. In combination with oxygen present in the atmosphere, this process promotes corrosion, as the metal can oxidize and, over time, deteriorate.

Moisture facilitates the transfer of ions, and oxygen is necessary to form oxides or rust. This is particularly relevant for metals such as iron, which can rapidly corrode in the presence of both elements. The impact of moisture and oxygen is significant in various environments, including both natural and industrial settings, making them the primary factors contributing to atmospheric corrosion.

While extreme temperatures, high-pressure conditions, and direct sunlight exposure can affect metals and materials in various ways, they do not play as direct a role in the electrochemical corrosion process as moisture and oxygen do.