AC-induced corrosion continues to be a controversial subject and a full agreement on influencing
parameters and mechanism has not yet been achieved. The influence of AC-induced interference on
the localized corrosion resistance of passive metals is discussed on the basis of laboratory test results.
Tests were performed on stainless steel with different chemical composition (PREN 18 and 25) in soilsimulating
solution and on carbon steel in alkaline solution (under cathodic protection of carbon steel,
the local pH at the soil-steel interface is higher than 10, so carbon steel is in passive condition).
Potentiodynamic tests were also carried out to analyse the effects of AC stationary interference on
passivity current density. Applied AC was in the range of 10 A/m2 to 100 A/m2. Results allow to
evaluate the effect of AC on: time-to-corrosion, AC critical current density and corrosion morphology.
Key words: AC-induced corrosion, AC-interference, passive metals, passivity current density.