CORROSION OF LEAD BY ORGANIC-ACIDS

The corrosion of lead in 10(-4)-10(-1) M aerated solutions of oxalic, tartaric and citric acids has been studied by open-circuit potential, cathodic polarisation and corrosion rate measurements. The corrosion r ate of lead increases with increase in acid concentration. A linear re lationship is observed between the steady-state potential (E) and the logarithmic concentration of the organic acid (log C) for the three ac ids studied. The order of aggressiveness being, oxalic > tartaric > ci tric. The corrosion of lead increases with pH in the range 2.5-5.5 ind icating that the corrosion process is anodically controlled. Polarisat ion studies show the corrosion mechanism to be under anodic control du e to complexing of lead ions with the acids.