On Corrosion-Induced Creep and the Shedding of Oxide Pest From Metal Plates

We consider a boundary value problem for a flat plate of an originally ductile metal that is subject to surface corrosion. Corrosion is modeled with the aid of two mobile interfaces. The leading interface is an oxidation front where volumetric expansion generates stress. This interface is initially present, with its location taken as prescribed. The trailing interface is a failure front associated with the shedding of oxide pest. This interface is not initially present, rather it first appears at some finite time into the process, and is determined via a stress-based failure criterion. The problem is reduced to a set of ordinary differential equations whose form changes depending on whether or not shedding has initiated. Numerical treatment shows a substantial increase in creep rate due to oxide shedding.