The Corrosion Behavior of Galvanized and Cold Rolled Steels

Samples of painted cold rolled and galvanized steel have been exposed to laboratory cyclic and salt spray tests, accelerated outdoor exposure in Florida, and on a vehicle in Detroit. Samples have been evaluated visually and by scanning electron microscopy and microprobe analysis.

Galvanized steel performed better than cold rolled steel in all but the salt spray test. Some of the factors influencing the spread of corrosion beneath a paint film have been identified.