Corrosion and hydrogen permeation characteristics of pipeline steel in synthetic near-neutral pH environments and development of cracking environments

In this research, synthetic near-neutral pH soil solutions were prepared that were based on the solutions extracted from sites where near-neutral pH SCC had occurred. Potentiodynamic polarization tests were used to investigate the corrosion characteristics, and hydrogen permeation tests were used to investigate the rate of hydrogen uptake into X-65 pipeline steel in these solutions. Influences of the electrolyte chemistry as well as the carbon dioxide level in the purging gas were investigated. Moreover, precipitation tests were used to study the effects of cathodic potentials, electrolyte chemistry and carbon dioxide content or lack thereof on the development of cracking environments.