The purpose of this work was to study the effect that turbulent flow has on the electrochemical
behaviour of a 3-amino-1,2,4-triazole (aminotriazole or 3-AT) based corrosion inhibitor. The
experiments were carried out in a rotating cylinder electrode (RCE) and a 4 l laboratory flow-loop. The
test environment used in all experiments was a 3% NaCl solution saturated with CO2 at 20C.
Potentiodynamic polarization curves, polarization resistance and electrochemical impedance
spectroscopy (EIS) measurements were used to determine the electrochemical behaviour of the steel in
the environment at different flow rates and inhibitor concentrations. The inhibiting effect of the tested
substance is strongly dependent on the hydrodynamic conditions of the environment. As the turbulence
of the environment increases, the efficiency of the inhibitor also increases. This increment could be
associated to an increased migration of the inhibitor, from the bulk of the solution towards the surface of
the corroding electrode. This increased migration can generate a better coverage of the surface of the
corroding electrode and therefore a decrement of icorr.
When the efficiency of this inhibitor is estimated, controlled hydrodynamic conditions must be taken
into account. Otherwise the value of efficiency that is calculated can be underestimated.
Keywords: aminotriazole, corrosion, CO2, inhibitor, flow