Phosphate ions used as green inhibitor against copper corrosion in tap water

M. B. VALCARCE; M. VÁZQUEZ

CORROSION SCIENCE

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2010 vol. 52 p. 1413 - 1420

0010-938X

Three dosages of PO43- ions are evaluated as corrosion inhibitors of copper in artificial tap water by measuring the corrosion potential, polarization resistance, electrochemical impedance and reflectance spectra. The water used is moderately hard, highly carbonated and chloride-rich. The results show that the surface film is composed by Cu2O. When the inhibiting agent is added, the film becomes thicker, denser and more compact. This behaviour is attributed to CuO incorporating into the passive layer. The optimal dosage of inhibitor is 10 mg l-1 P when the polarization resistance increases three times. The inhibitor retards the pit initiation, without hindering pit growth