Silicon ion implantation on austenitic and ferritic stainless steels against localized aqueous corrosion

Silicon ion implantation has been used as a surface modification technique in order to improve the corrosion resistance of two stainless steels with s imilar passive layers but different microstructures, such as AISI 304 (aust enitic) and AISI 430 (ferritic). For each steel, different doses of silicon ion implantation (1 x 10(14), 5 x 10(14), 1 x 10(15) ions/cm(2)) at an ene rgy of 80 keV have been tested. Theoretical simulations using the TRIM 96 c omputer code have been performed in order to estimate the Si implantation p rofiles. The corrosion resistance of the Si-implanted stainless steels was analysed using electrochemical impedance spectroscopy (EIS) in a 0.5 M NaCl solution. The surface was characterised by auger electron spectroscopy (AE S). The effect of optimum doses of Si-implanted stainless steels on the cor rosion behaviour is discussed. (C) 2000 Elsevier Science B.V. All rights re served.