Factorial design study of corrosion in Tin-Free Steel (TFS) tinplate of tomato paste

Abstract

In this paper, a sample of tin-free steel tinplate from a tomato paste was analyzed for electrochemical corrosion. The dependence between the variables pH, NaCl content and temperature was evaluated through factorial design. For the body it is possible to verify the presence of Sn thin layer. On the other hand, in the samples of the bottom and the top it is not possible to observe this layer. At low temperatures (below 22 °C) and NaCl concentration from 500 to 2000 ppm the pH do not influence the corrosion rate (CR). Furthermore, for NaCl concentration values below 2000 ppm the temperature does not seem to influence the CR. Thus, working at a chloride concentration below 2000 ppm, the corrosion rate seems to remain the same for changes in pH and temperature.