Study on the corrosion behaviours of API X65 steel in wet gas environment containing CO₂

An impingement jet system was used to study the corrosion of API X65 steel in a wet CO₂-containing environment via electrochemical tests, surface analysis technique and computational fluid dynamics simulation. The corrosion rate decreased in the wet environment compared to that in the bulk solution. When under flow condition, corrosion rate increased with the flowing velocity, especially when above the critical flowing velocity. Continuous electrolyte film was formed and electrochemical reaction started to occur in about 70% RH, and the critical RH appeared at 70–80%, above which pit size and amount remarkably increased with flow velocity.