Extemal stress corrosion cracking is a significant threat to the integrity of operating pipeline systems. Both intergranular and transgranular cracking are seen but these modes of failure are identified with different environmental conditions. Understanding how these conditions arise can improve site selection and risk based management approaches to integrity maintenance. This paper reviews the different electrolytes associated with both high pH and near neutral pH SCC in the field and discusses processes responsible for creation of solutions amenable to the potential cracking of line pipe steel under disbonded coatings.
Keywords: high pH SCC, neutral pH SCC, electrolytes, coatings, deposits, pipelines