Aging pipeline infrastructure is subject to various degradation modes, in particular there is a growing concern of stress corrosion cracking (SCC) from external environments. The current program focused on developing data in high pH carbonate/bicarbonate environments as a function of temperature, applied potential, and loading modes in three different pipeline steels. Crack growth rate measurements indicate that the susceptibility to SCC increases with increasing temperature and is higher under low cycle fatigue compared to constant K conditions. The crack growth rate behavior at each temperature was a strong function of the applied potential, coinciding with the potential range of the active passive transition in the polarization scans. The potential at which a peak in crack growth rate was observed, coincided with the peak value of the ratio of the current density from the fast to slow scans. The crack growth rate data was fitted to a crack tip strain rate based model to account for both the cyclic as well as static crack growth rate. The model developed was able to successfully predict prior data in literature generated under various loading conditions.

This content is only available as a PDF.
You do not currently have access to this content.