TY - JOUR AU - Arenas, M. A. AU - Damborenea, J. J. PY - 2005/12/17 Y2 - 2024/03/29 TI - Generation of conversion coatings using rare earths on galvanised steel JF - Revista de Metalurgia JA - Rev. metal. VL - 41 IS - Extra SE - Articles DO - 10.3989/revmetalm.2005.v41.iExtra.1070 UR - https://revistademetalurgia.revistas.csic.es/index.php/revistademetalurgia/article/view/1070 SP - 433-437 AB - Cerium conversion coatings are formed on commercial galvanized steel and a generation mechanism is suggested. The best conversion coatings were found using 10,000 ppm CeCl<sub>3</sub>·7H<sub>2</sub>O + 0,3 % vol. of H<sub>2</sub>O<sub>2</sub> with a pH of 1.3. A cathodic potential, -100 mV versus corrosion potential, was applied during the treatment at a constant temperature of 43 °C. SEM micrographs have revealed a non uniform coating thickness between 1-2 μm. Polarization curves in 3.56 wt. % NaCl exhibited an inhibition power of about 94 % with respect to the galvanized steel. The proposed mechanism suggests that the Ce (III) ions in the solution were oxidized by H<sub>2</sub>O<sub>2</sub> to Ce (IV) which then precipitated as CeO<sub>2</sub>. The applied voltage could cause a higher presence of Ce<sup>3+</sup> in the film maybe due to an electroreduction process of cerium (IV) in the film to cerium (III). ER -