Understanding the Stress Corrosion Cracking of X-65 Pipeline Steel in Fuel-grade Ethanol

Currently, the major concern on transporting fuel-grade ethanol (FGE) via existing pipeline is the stress corrosion cracking (SCC) of carbon steel in such environment. Nationwide, collaborative efforts have been made by various research groups to understand the failure mechanisms and address the protection methods. The focus of this paper is to discuss the ethanol chemistry effects on SCC and provide a mechanistic picture on crack initiation and growth in simulated fuel-grade ethanol (SFGE). Chloride, pHe and water are critical for SCC in this system. It was also found the film related anodic dissolution controls the cracking dynamics during slow strain rate test (SSRT) in SFGE.