Electrochemical behavior of stainless steel AISI 430 exposed to simulated food

Abstract

Due to the excellent properties of stainless steel, these materials have a variety of applications among which is the food processing industry. One of the main problems in this industry is the possible releasing of metal ions towards food. For this reason, it is very important to know corrosion behavior of steels that are used in this industry. In this study the release of Fe, Cr and Ni ions and the electrochemical behavior of AISI 430 steel with three different surfaces finishes in contact with a solution that simulates food contact (acetic acid 3% v/v) was evaluated. For this, the influence of the surface finish (polished by SiC paper 600, 1200 and 1500 grit) and the exposure time to the solution (4 and 10 days) at different temperatures (25, 60 and 100°C) was analyzed by atomic absorption spectroscopy, linear polarization resistance and potentiodynamic polarization curves. The results show that the releases of Fe, Cr and Ni ions, the linear polarization resistance and the corrosion rate of the AISI 430 steel depend on surface finish and temperature. The lower corrosion rate was obtained when the material had the smooth surface finish, in such a way that it is possible to avoid health risks due to the release of metal ions.