Corrosion Reasons of a Retractable Corrosometer on Offshore Oilfield

In offshore made of 316L stainless steel retractable corrosometer was repeatedly corroded locally. Serious corrosion damage occurred only 2 or 3 months after new corrosometer was installed. In order to find out the corrosion reason and support the future corrosion control, a typical sample was characterization by means of physical and chemical inspection, electrochemical analysis. The results showed that the reason of the local ized corrosion was waterline corrosion caused by concentration cell, and Cl- accelerated the whole corrosion process.