Factors Affecting the Corrosion of Tin in the Presence of Reducible Inorganic and Organic Substances

摘要

The purpose of these studies is to obtain a better understanding of the role which antimony plays in accelerating the corrosion of tin. Tin-antimony alloys were prepared by electrodeposition and the corrosion rates were determined from polarization data obtained in deaerated 0.33M citric acid. The corrosion rates were linearly related to the antimony concentration in the alloy and could be described by the following equation: Corrosion rate in A/sq. m. = 0.0003 + 0.000079X where X is the antimony concentration in the tin in ppm. Nitrite additions to the deaerated citric acid greatly accelerated the corrosion rate. The effect of nitrite could be described by the following equation: Corrosion rate in A/sq. m. = 0.0003 + 0.021Y where Y is the nitrite concentration in the citric acid in ppm. The nitrite results and the great effect of antimony on the corrosion rate were attributed to the fact that a partially oxidized surface serves as a remarkably effective catalyst for the cathodic hydrogen evolution of tin. (Author)