Chemical and electrochemical conditions on steel under disbonded coatings: the effect of previously corroded surfaces and wet and dry cycles
Chemical and electrochemical conditions on steel under disbonded coatings: the effect of previously corroded surfaces and wet and dry cycles
- New search for: Perdomo, J.J.
- New search for: Chabica, M.E.
- New search for: Song, I.
- New search for: Perdomo, J.J.
- New search for: Chabica, M.E.
- New search for: Song, I.
In the study, the effectiveness of cathodic protection (CP) in a simulated highly insulating disbonded tape has been studied for previously corroded surfaces. The potential of the steel, pH and oxygen concentration of the solution were measured for a variety of initial steel surface conditions. Also, the effect of wet and dry cycles on the chemistry changes in the crevice solution was studied as a function of the starting surface condition. A cell was used to model disbonded regions of a tape-coated, buried steel pipeline under impressed current cathodic protection. Deaeration within the crevice causes prerusted steel surfaces made up to gamma-FeO(OH) to reduce to Fe3O4 as long as the crevice is filled with solution even in the absence of CP. The rate at which potential decreased to the more negative direction was slower than previously reported for bare steel. A combination of high alkalinity, low oxygen concentration and appropriate applied potential, work together to form magnetite and as a result to mitigate corrosion on pipelines.
Document information
Chemical and electrochemical conditions on steel under disbonded coatings: the effect of previously corroded surfaces and wet and dry cycles
Chemische und elektrochemische Bedingungen auf Stahl unter nichthaftenden Beschichtungen: Der Einfluss vorkorrodierter Oberflächen und feucht/trocken-Zyklen
Corrosion Science ; 43 , 3 ; 515-532
2001
18 Seiten, 5 Bilder, 2 Tabellen, 21 Quellen
Article (Journal)
English
unterirdische Rohrleitung , Stahl , beschichteter Werkstoff , kathodischer Schutz , Korrosionsmechanismus , Korrosionsversuch , Voroxidation , zyklische Belastung , Trocknen , Feuchtigkeit , Eisenoxid , Eisenhydroxid , Spaltkorrosion , elektrisches Potenzial , elektrochemisches Potenzial , pH-Wert , Basizität , Sauerstoff , Korrosionsprodukt , Röntgenbeugung , Oberflächenzustand , bandbeschichteter Stahl , Grundwasser
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