Chromium–nickel stainless steels, otherwise chemically resistant, can suffer very high corrosion rates during nitric acid production using Pt–Rh catalyst. The corrosion of these steels is shown to be the result of the establishment of mixed electrode potentials between chromium–nickel steels and Pt–Rh deposits as well as of microgalvanic couples associated with the different potentials of strained and unstrained material in HNO3 electrolyte.