Galvanic corrosion can occur under which conditions?

• A. Immersion and Atmospheric Condition
• B. Dry Air and Vacuum
• C. High Temperature and Low Humidity
• D. Static Mechanical Load

Answer: (A)

Galvanic corrosion requires two dissimilar metals in electrical contact with an electrolyte present. In immersion, water provides the electrolyte continuously, allowing electrons to flow between metals and one metal to corrode preferentially. In atmospheric conditions, humidity can form a thin film of electrolyte on metal surfaces (especially if salts or contaminants are present), enabling the same electrochemical process to occur even without submersion.

The other scenarios don’t support galvanic corrosion. Dry air and vacuum lack enough moisture to form the necessary electrolyte, so the galvanic cell can’t operate. High temperature with low humidity still depends on having a conductive moisture layer to drive the reaction, which isn’t reliably present under those conditions. Static mechanical load isn’t about electrochemical reactions at all, so it doesn’t drive galvanic corrosion.

Therefore, immersion and atmospheric condition provide the environments where galvanic corrosion can occur.