Alternating current (AC) corrosion mechanism is not well understood, particularly as it applies in cathodic protection (CP) condition. The aim of this research is to propose an AC corrosion mechanism of carbon steel in CP conditions. Electrochemical tests were carried out on carbon steel in simulated soil conditions to identify AC corrosion risk related parameters during CP, like AC and CP current density ratio and protection potential. A corrosion risk diagram is proposed: overprotection seems to be the most dangerous condition in the presence of AC. A two-steps corrosion model is proposed: AC causes the local breakdown of the nanosized passive layer formed in CP condition (Step 1) and then high pH corrosion can occur (Step 2) due to the high alkalinity in overprotection condition. To study the effects of AC on passive films, corrosion tests were performed on an austenitic stainless steel in neutral solution in the presence of chlorides.
A proposal of AC corrosion mechanism in cathodic protection
Ein Vorschlag für den Korrosionsmechanismus beim kathodischen Schutz durch Wechselstrom
2011
4 Seiten, 3 Bilder, 18 Quellen
Aufsatz (Konferenz)
Englisch
Marine corrosion and cathodic protection
TIBKAT | 2022
|Cathodic protection monitoring detects corrosion problems
Tema Archiv | 1976
|Cathodic corrosion protection in hydraulic steel construction
Online Contents | 1998
|Corrosion and cathodic protection in arctic water
Tema Archiv | 1979
|Prevent corrosion by cathodic protection - part 13
Tema Archiv | 1989
|