Stress corrosion cracking anodic dissolution and hydrogen permeation in pipeline steels

摘要

The phenomenon of Transgranular Stress Corrosion Cracking (TGSCC) has been observed in buried pipelines where in contact with diluted solution under disbonded coating. It was proposed that such cracking is due to a mechanism related to hydrogen evolution and permeation at the crack tip, as observed in nuclear pressure vessel steels and other low alloy steels. In this paper, the cracking mechanism of TGSCC is discussed. The combined effect of Hydrogen permeation and anodic dissolution has been experimentally investigated by im- Posing different cathodic protection levels: from free corrosion potential(-750 mV SCE), to -1300 mV SCE.