Effect of pH on the Corrosion and Repassivation Behavior of TA2 in Simulated Seawater.

ABSTRACT

The effect of pH on the corrosion and repassivation behavior of TA2 in simulated seawater was studied using electrochemical tests, immersion experiments, and surface morphology topology analysis. The results show that Ecorr and Rf increased while ipass and weight loss rate decreased as the pH of simulated seawater increased. The TA2 passive film was determined to be mainly composed of a large amount of TiO2 and a small amount of TiO. The repassivation function of TA2 can be expressed as E = -0.1375 + 0.0532ln(t - 1.241) for a simulated seawater pH of 8.2. The parameter b, which represents the slope of the potential-time curve during the friction electrode test, was used to evaluate the repassivation behavior of TA2. The increase in pH value was observed to promote the repassivation speed of the passive film, which is beneficial to the corrosion resistance of TA2.