Electrochemical and stress corrosion cracking behaviour of micro-alloyed steels in CO2/HCO3- environment

Tmnagmmdar Stress Corrosion Cracking @GSCC) is a relatively recent form of stress corrosion cracking of buried gas mrdoilpipelines.Aimof thepresentworkis toevaluatetheelectrochemicalandSCCbehaviourof microalloyedsteels inC02/HCO~envimnmentainorderto better datine the mechanisms involved in TGSCC. It baa been shown that in TGSCC environment all the te$ed steels remain active. It is the presence of the couple C@/HCOj and of a pH around seven to play a major rule in the TGSCC. There are strong evidences that TGSCC is caused by the entrance of atomic hydrogen into the metal, hindered by the presence of corrosion products due to the environment. Temperature seems to irrbibit TGSCC. No SCC was obtained by constant load and constant deformation tests.