Mitigating Corrosion of Carbon Steel in Supercritical CO2 Environments using HVOF Coatings

Thursday, May 14, 2015: 9:00 AM
Room 101A (Long Beach Convention and Entertainment Center)
Dr. Shiladitya Paul , TWI, Cambridge, United Kingdom
This paper reports the use of HVOF-sprayed corrosion resistant alloy (CRA) coatings to protect carbon steel in supercritical CO2-containing environments such as oil and gas wells. 316L, Ti, alloy C-276 and alloy 625 were sprayed onto carbon steel substrate using a JP5000 and tested in 3.5wt.% NaCl solution in 100bar CO2 at 40°C and 80°C for 30days. Microstructural characterisation revealed that the coating protected the steel substrate from supercritical CO2 corrosion. The bare steel formed a siderite (FeCO3) scale while no such scale was seen in the case of CRA-coated steel. It can be concluded that thermally sprayed CRA coatings provide a cost-effective corrosion mitigation method for infrastructure likely to be in contact with wet supercritical CO2. However, care must be taken to ensure that the thermally sprayed layer does not have any through-thickness porosity; else, such coatings may accelerate corrosion of the underlying steel due to galvanic interactions.
See more of: Corrosion 2
See more of: Thermal Spray Applications