Erosion-Corrosion in Oil and Gas – Stainless Steel Under De-Aerated Slurry Impingement Attack

Stainless steels are known for their excellent corrosion properties when they can rely on the passive film. The passivity is attributed to the ability to form an oxide “passive” layer on the metallic surface, as soon as it is exposed to an oxygen-containing environment. 
The respond of passivating materials to the combined attack of erosion and corrosion is still not well understood, when the passive film is breached by abrasion. In this study a superaustenitic stainless steel was tested in carbon dioxide saturated artificial seawater under erosion-corrosion attack with various levels of severity. The influence of changing velocity and solid loading was in the focus of this work, giving information about the passivity maintenance under de-aerated conditions.
Erosion-corrosion tests have been conducted using a recirculating flow loop involving impingement of a liquid/solid slurry onto the specimen surface. Integrated electrochemical measurements enable the corrosion rate to be assessed as a function of solid particle content and flow velocity.