Imaging of the effects of pitting corrosion with the use of AFM

Pitting corrosion is a local attack on a metal surface, limited to a point or small area, which appears as a hole. Pitting corrosion is one of the most harmful forms of corrosion due to the fact that it is associated with small, difficult to detect damage, that can even lead to perforation of the structure. A single pit may range in size from micrometers to millimeters, which may make it difficult to identify it quickly. This type of corrosion usually occurs in alloys that are protected by a permanent oxide layer, such as stainless steels, nickel alloys, aluminium alloys, in environments containing aggressive compounds such as chlorides or thiosulphates. The measurements included in the set were made on the surface of AISI304 high-alloy steel, previously subjected to anodic electrochemical polarization in a 3% brine solution, in order to induce a local attack process. Measurements were made on the dried surface of the sample using the semi-contact technique with the use of the NSG30 probe. The collection contains 14 images.
[1] P. Guo, E.C. La Plante, B. Wang, X. Chen, M. Balonis, M. Bauchy, G. Sant, Direct observation of pitting corrosion evolutions on carbon steel surfaces at the nano-to-micro- scales, Sci. Rep. 8 (2018) 7990. doi:10.1038/s41598-018-26340-5.