The effect of pH on the kinetics and mechanism of Armco iron (99.99%)
corrosion in deaerated, nitrogen saturated solutions at 21 degrees C w
as studied. The total concentration of sulphate ions in the solutions
tested was 0.5 M. The increase in the pH in the range tested caused a
change in the Tafel anodic straight line slope from 28 mV dec(-1) (pH
0.6) to 75 mV dec(-1) (pH 4.15), without a change in the anodic mechan
ism. For the anodic dissolution the order of reaction with respect to
the OH- ion was found to be -1. The effect of pH on the corrosion pote
ntial and current was also found.