Abstract
As the oil and gas sector moves towards exploration of deeper and remote wells, corrosion protection of conduits carrying hot fluids subsea becomes critical. Thermally Sprayed Aluminum (TSA) has been used to protect offshore structures for many years at ambient temperatures. However, the melting point of aluminum, and the limited corrosion rate data indicate that they are likely to perform well at high temperature in subsea environment. Even when TSA is partly damaged the underlying steel is protected cathodically. With time, the formation of deposits on the cathodically polarized steel also offers protection. Nonetheless, not much in known regarding the protection mechanism offered by TSA to at elevated seawater temperatures. In particular, the mechanism of calcareous deposit formation at elevated temperature is little understood. This paper reports micro-scale surface characterization data on damaged TSA-coated carbon steel exposed to boiling synthetic seawater. The kinetic information regarding the rate of formation of calcareous deposits is also presented.
