OBSERVATIONS ON THE INFLUENCE OF MICROSTRUCTURE ON ELECTROLYTIC TINPLATE CORROSION

Corrosion processes on the stratified structure of electrolytic tinpla tes were characterized by means of alloy-tin couple, pickle-lag, anodi c polarization tests, and scanning electron microscopy analyses. To st udy polarization, citric-citrate and acetic-acetate solutions were emp loyed as artificial media while tomato sauce, canned razor-clams, and mussels were representative of real media. The results made it possibl e to establish a direct relationship between continuity homogeneity, a nd crystallization density of each layer and its resistance to corrosi on processes. The continuity and homogeneity conditions also involved organic layers having a protective role.