Evaluation of the anticorrosive behavior of epoxy-Nb2O5 paint in high temperatures submitted to the environment with sulfuric acid

The aim of the present work is to evaluate the corrosion resistance of epoxy-Nb 2 O 5 paint in acid atmosphere and high temperatures. For comparison, samples of SAE1020 carbon steel were coated with an epoxy-Nb 2 O 5 paint and an epoxy commercial paint. The samples were partially immersed for 720 h and 1440 h in 40% (v/v) H 2 SO 4 solution at temperatures of 25°C, 60°C, and 80°C. The degradation analysis, mechanical characterization, and electrochemical measurements of the samples were carried out after immersion period. The coatings were characterized by scanning electron microscopy. Electrochemical impedance spectroscopy was used to evaluate the electrochemical behavior. Results showed the epoxy-Nb 2 O 5 paint was less blistering, cracked, flaked, and rusted than the commercial epoxy paint samples. However, it was important to note that the increase in temperature led to the degradation of epoxy-Nb 2 O 5 paint. The addition of temperature was probably responsible for the degradation of epoxy resin over the immersion time.