Autori: Lingvay Iosif, Lingvay Carmen

Editorial: Coordinator - Adel Abdul Azim, Egyptean Corrosion Society, The 25th Annual Conference of Egyptean Corrosion Society "Corrosion Problems in Industry" Egycorr 2006, 4-6 December 2006, Ain El Sukhna, Egypt, CD-paper no. 11, 2006.

Rezumat:

The European operators of energy transportation systems – pipelines – have reported numerous failures (corrosion defects – defects / holes in the metal of gas and oil pipes) in the last two decades. This majority of these failures are due to a new form of corrosion, namely stray currents corrosion. Issue of the operational safety for these grids (gas and oil pipelines) is of great impact: economic, social and environmental. Therefore the scientists in the field and the European regulations / standards focus their attention on this new kind of corrosion. Recently, a lot of papers approaching the problem of accelerated corrosion due to stray AC currents were presented to the last sessions of European congresses / conferences in the field (CEOOCOR, EUROCORR).
The present paper deals with various aspects concerning AC corrosion phenomenon such as AC stray currents origination, influence of alternating signals on the kinetics of the corrosion reactions, specific methods worldwide destined for corrosion mitigation. Also, an original method developed in Romania and which is high efficient is shown. Thus, the method ensures: electric safety of metallic pipes to hazardous / random charges with undefined polarity and which generate dangerous voltages (lighting strikes inclusively), polarized drainage of stray DC currents, treatment of stray alternating currents by their rectification and transforming in protection cathodic current, therefore increasing of cathodic protection effectiveness.

Cuvinte cheie: underground pipelines, corrosion, DC stray currents, AC stray currents, control of corrosion, electric safety, cathodic protection, grids’ operational safety, gas transportation pipelines, oil transportation pipelines // underground pipelines, corrosion, DC stray currents, AC stray currents, control of corrosion, electric safety, cathodic protection, grids’ operational safety, gas transportation pipelines, oil transportation pipelines