Synthesis, Characterization and Evaluation of Apatitic Tricalcium Phosphate as a Corrosion Inhibitor for Carbon Steel in 3 wt% NaCl

Abstract

In this study, we did the synthesis of apatitic tricalcium phosphate, which was characterized by Chemical Analysis, Fourier-Transform Infrared Absorption Spectroscopy and X-Ray Diffraction. The product obtained is apatitic tricalcium phosphate PTCa with the chemical formula Ca 9 (HPO 4 )(PO 4 ) 5 (OH) and a Ca/P ratio equal to 1.5. We evaluated the inhibitory power of PTCa on carbon steel in a NaCl 3 wt% medium by different electrochemical techniques: Stationary polarization, Electrochemical impedance spectroscopy. The results obtained revealed that the apatitic tricalcium leads to a systematic decrease in the kinetics of steel corrosion processes. This decrease depends on the concentration of the compound, the temperature and the immersion time. It reaches 87% for a concentration of 200 ppm. Thermodynamic parameters of the activation process and metal dissolution were calculated and discussed.