When can corrosion occur without the presence of water?

Corrosion can indeed occur at high temperatures, particularly in environments where certain metals are exposed to reactive gases, even without the direct presence of moisture. High temperatures can accelerate the rate of chemical reactions, making it easier for oxidation and other corrosive processes to take place. For example, metals can react with sulfur or other gases present in the atmosphere, leading to corrosion products forming on the surface.

While oxygen is often a critical factor in the corrosion process, it does not negate the role that temperature plays. A dry environment can also contribute to corrosion, particularly via mechanisms like stress corrosion cracking or corrosion caused by thermal oxidation. Therefore, the presence of high temperatures provides a unique condition under which corrosion can occur through different chemical reactions, emphasizing the importance of temperature in the corrosion process.