This experiment aims to determine the corrosion characteristics of Maraging steel 250 grade, AISI 4340 aeronautical steel and Inconel 625 which are used in aeronautical applications under normal and heat treated conditions. Potentio dynamic polarization studies in sea water environments of 3.5% NaCl and 5% Nacl are done in order to understand the corrosion behaviour and corrosion rates of each metal under different conditions. © 2014 University of Manchester and the authors.