Transgranular stress corrosion cracking (TGSCC) of buried carbon steel fuel transmission pipelines has
been reported to occur on pipelines that are protectively coated and subjected to cathodic protection.
The objective of this research was to investigate the conditions under which near-neutral pH
environments can be formed. Specifically, this research focuses on how the pH of solutions change
with applied potential and CO2 exposure. Potentiodynamic polarization tests were performed in
solutions with different ground water constituents to see their role in anodic and cathodic behavior of
pipeline steels. Application of cathodic protection alters the pH at the steel surface, shifting the
environment outside of near-neutral pH conditions. Coupon exposure tests and potentiodynamic results
suggest that the environment of TGSCC is possible in a wide range of temperatures and compositions.