Anti-Corrosion Coatings Based on Nb2O5 - a Comparison Between two Coatings Technology: Thermal Spray Coating and Epoxy Paint

Niobium pentoxide (Nb2O5) has gained prominence as an anti-corrosive pigment. The performance of anti-corrosive coatings based on Nb2O5 was tested in an environment with an acid atmosphere and at high temperatures. For comparison, SAE 1020 carbon steel samples were coated with two anticorrosive coatings based on Nb2O5: applied by thermal spray and epoxy paint. The samples were partially immersed in the laboratory for 720 h and 1440 h in a 40% (v/v)H2SO4 at 25 degrees C, 60 degrees C, and 80 degrees C. An in-situ evaluation was carried out of chemical industry installations over 4383 h in microcli mates with the presence of corrosive agents at temperatures up to 70 degrees C. The results obtained showed that the Nb2O5 coatings applied by thermal spray offer better anti-corrosive performance under immersive conditions. In contrast, under conditions submitted to steam, both the Nb2O5 coatings applied by thermal spraying and epoxy-Nb2O5 paint show excellent anti-corrosive behavior.