AFM study of steel corrosion in aqueous solutions in concrete

摘要

Early corrosion stages are studied in carbon steel by means of a solution simulating that contained in concrete pores. Non-carbonated solution contains 5% NaCl. The atomic force microscopy (AFM) technique is used to study material performance after different immersion times (up to 48 h). Obtained data are compared to electrochemical ones (corrosion potential and polarization resistance). Analysis of images and roughness evolution along time shows that steel initially tends to reach passivity, although the passive layer rapidly loses its protective character due to chloride attack.