Nickel-containing stainless-steel are known to undergo regular oscillations in corrosion potential when exposed concentrated sulfuric acid. The change in corrosion potential of the steel is known to be related to the spontaneous and repeated; formation and breakdown of a passive film. Using a series of kinetic equations to describe the active and passive state behavior of the steel, a model was developed which reproduces the conditions which cause the instability exhibited by this system. The model quantitatively simulated the observed oscillation in corrosion potential for this system. (C) 2013 The Electrochemical Society. All rights reserved.