Application of Scratch Testing for the Assessment of the Adherent Properties of Scales and CO2 Corrosion Product Layers and their Relation to Corrosion

Protective corrosion product layers, such as iron carbonate, can govern pipeline corrosion; their formation being associated with operational conditions (high [Fe2+], pH > 6.0, T > 70 degrees C). Brines contain Ca2+ that can incorporate as a substitutional cation in the iron carbonate lattice, potentially compromising the mechanical integrity of the protective layer. This work utilized scratch testing as an analytical technique that provides more information on layer adherence than indentation methods. It was demonstrated that the presence of iron calcium carbonate layers contributes to the formation of a protective and mechanically stable iron carbonate layer adjacent to the steel surface.

Automated summary

Operational conditions play a crucial role in controlling pipeline corrosion and iron carbonate may be a key factor in this process. Research indicates that the presence of iron calcium carbonate layers contributes to the formation of a protective and mechanically stable iron carbonate layer.