The subject of AC corrosion on cathodically protected pipelines, even if already known, arose in the world of corrosion engineers only in the 80ies. Up to that time, only a few countries in Europe where AC traction systems were used were involved and had experience on this subject.
Starting from the 90ies, the problem of AC interference due to electric power lines has massively grown, because of the intensive use of very high electrical resistance coating of pipelines, but also due to the increasing number of parallelisms of electric power lines and the development of high speed trains, fed with alternating current. The problem of reducing AC interference on gas pipelines so that AC corrosion could be minimized is the origin of quite a harsh controversial debate in Europe; nonetheless, a Technical Specification has been delivered in the framework of CEN (European Committee for Standards) Works, the CEN/TS 15280, March, 2006 . This Technical Specification is nowadays going to be transformed into a full validity Standard.
The paper highlights the State of the Art in the technical/scientific knowledge of this subject. Its mitigation, the studies and the issue of relevant Standards & Recommendations will also be dealt with.
Keywords: AC corrosion, AC corrosion coupons, E.R. Coupons resistive, inductive, capacitive interference, AC discharge device, incubation time