Electrochemical Tests on the Optimum Cathodic Protection Potential of X70 Steel in the Presence of AC Interference

2011 ◽  
Author(s):  
Zili Li ◽  
Hongna Hao ◽  
Qingmiao Ding
Keyword(s):  
Cathodic Protection ◽  
Electrochemical Tests ◽  
Protection Potential ◽  
Ac Interference

scholarly journals AC Corrosion of Carbon Steel under Cathodic Protection Condition: Assessment, Criteria and Mechanism. A Review

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2158
Author(s):  
Andrea Brenna ◽  
Silvia Beretta ◽  
Marco Ormellese
Keyword(s):  
Carbon Steel ◽  
Cathodic Protection ◽  
Grey Literature ◽  
Reference Electrode ◽  
Steel Structures ◽  
Localized Corrosion ◽  
Corrosion Mechanism ◽  
Narrative Literature Review ◽  
Protection Potential ◽  
Ac Interference

Cathodic protection (CP), in combination with an insulating coating, is a preventative system to control corrosion of buried carbon steel pipes. The corrosion protection of coating defects is achieved by means of a cathodic polarization below the protection potential, namely −0.85 V vs. CSE (CSE, copper-copper sulfate reference electrode) for carbon steel in aerated soil. The presence of alternating current (AC) interference, induced by high-voltage power lines (HVPL) or AC-electrified railways, may represent a corrosion threat for coated carbon steel structures, although the potential protection criterion is matched. Nowadays, the protection criteria in the presence of AC, as well as AC corrosion mechanisms in CP condition, are still controversial and discussed. This paper deals with a narrative literature review, which includes selected journal articles, conference proceedings and grey literature, on the assessment, acceptable criteria and corrosion mechanism of carbon steel structures in CP condition with AC interference. The study shows that the assessment of AC corrosion likelihood should be based on the measurement of AC and DC (direct current) related parameters, namely AC voltage, AC and DC densities and potential measurements. Threshold values of the mentioned parameters are discussed. Overprotection (EIR-free < −1.2 V vs. CSE) is the most dangerous condition in the presence of AC: the combination of strong alkalization close to the coating defect due to the high CP current density and the action of AC interference provokes localized corrosion of carbon steel.

scholarly journals STABILITY ASSESSMENT OF PIPELINE CATHODIC PROTECTION POTENTIALS UNDER THE INFLUENCE OF AC INTERFERENCE

2018 ◽  
Vol 66 ◽  
pp. 19-28
Author(s):  
Thabane Hendry Shabangu ◽  
Purva Shrivastava ◽  
Bolanle Tolulope Abe ◽  
Peter A. Olubambi
Keyword(s):  
Cathodic Protection ◽  
Stability Assessment ◽  
Ac Interference

Fatigue-Corrosion of High Strength Steels in Synthetic Seawater under Cathodic Protection

2020 ◽  
Vol 841 ◽  
pp. 294-299
Author(s):  
Sergio Lorenzi ◽  
Cristian Testa ◽  
Marina Cabrini ◽  
Francesco Carugo ◽  
Luigi Coppola ◽  
...  
Keyword(s):  
Cathodic Protection ◽  
Fatigue Behavior ◽  
High Strength Steels ◽  
High Strength ◽  
Loading Frequency ◽  
Offshore Pipelines ◽  
Synthetic Seawater ◽  
Steel Grades ◽  
Protection Potential ◽  
Fatigue Corrosion

The paper is aimed to the study of the corrosion-fatigue behavior of high strength steels for offshore pipelines. Tests have been performed in order to study fatigue crack growth in synthetic seawater under cathodic protection. The tests have been carried out on three different steel grades from 65 to 85 ksi with tempered martensite and ferrite-bainite microstructures. The effect of stress intensity factor, cathodic protection potential and cyclic loading frequency is shown.

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