Performance of Damaged Thermally Sprayed Aluminium in 10 MPa Supercritical CO2

Abstract This paper reports the performance of damaged thermally sprayed aluminium (TSA) in an aqueous solution pressurized with 10 MPa supercritical CO2 at 40°C. Carbon steel substrate with thermal spray aluminium coating was prepared, artificial defect was created, and the specimen were exposed to 3.5 wt.% NaCl solution pressurised with 10 MPa CO2. The specimen was taken out after 168h and post-test examination was carried out. Post-test visual examination indicate no significant signs of damage to the coating which was confirmed by microstructural characterization. The micrographs indicated promising behaviour of TSA with no significant corrosion was seen at the TSA-steel interface in the defect region. However, one must note that the test was carried out for 168 h and such short term test seldom give long-term corrosion performance. Nonetheless, the initial results looks interesting and provides some indication of TSA’s promise for protection of steel against CO2 corrosion. Further work is required to explore the efficacy of such coatings in carbon capture and storage (CCS) applications.