Evaluation of the inhibitor effect of l-ascorbic acid on the corrosion of mild steel

The influence of l-ascorbic acid (AA) on mild steel corrosion in pH=2–6 solutions was investigated using electrochemical and weight loss techniques. Optical microscopic analyses provided the surface condition. The maximum inhibitor efficiency has been found in 10−3 mol dm−3 AA, pH=4, solutions (69%). In these conditions, AA acts as a mixed-type inhibitor. Activation energies of 49.4 and 65.7 kJ mol−1 for the corrosion processes were observed in absence and presence of AA, respectively. The AA inhibitor effect could also be evidenced by surface optical images.