Grain size distribution effects on the corrosion behaviour of materials

While the effect of grain size refinement on the corrosion behaviour of materials is well studied, the effect of grain size distribution has not been explored. By utilising existing correlations between corrosion current and grain size, we derive relationships for corrosion current and grain size distribution. These relationships suggest that for the same average grain size, a broader grain size distribution leads to increased corrosion resistance in a non-passivating environment and vice versa in a passivating environment. These relationships are also used to predict the corrosion behaviour of bimodal microstructures. (C) 2012 Elsevier Ltd. All rights reserved.