Investigation of artificial pit growth in carbon steel in highly alkaline solutions containing 0.5 M NaCl under oxic and anoxic conditions

Abstract

Abstract We report an investigation of artificial pit growth (APG) in P355QL2 Grade Carbon Steel in the highly alkaline, synthetic concrete pore solution [sat. Ca(OH)2/NaOH of pH of 13.5]\xa0+\xa00.5\xa0M NaCl under both “oxic” and “anoxic” environmental conditions. The corrosion potential of the external surface, as well as the coupling currents flowing between the external surface and the pit tip and pit walls of the segmented carbon steel specimens under the selected conditions, were measured as a function of time and pit aspect ratio. The findings were interpreted in terms of the Differential Aeration Hypothesis (DAH).