An electrometric method for evaluation of the corrosion of lead alloys

In an electrometric method, the lead electrode is subjected to electrolyte and temperature conditions, as well as various states of polarization that simulate the service of lead/acid batteries. The resulting corrosion layer is first reduced to lead sulfate then to sponge lead. A linear relation is observed between the weight of the corroded lead and the surface area of the sponge lead after cathodic reduction of the corrosion layer. This surface area is determined by measuring the time required to cover the lead completely again with lead sulfate at a specified current density and standardized conditions, irrespective of the test solution and test temperature. The results are very reproducible. The application of the electrometric method proves to be effective for the evaluation of lead–antimony–arsenic alloys in a wide range of sulfuric acid concentrations and at temperatures between 25 and 60°C. The study also suggests that the recommendation to reduce the acidʹs relative density (rel. dens.) in lead/acid batteries operated in tropical climates may be harmful to battery life.