A methodology for the construction of the erosion-corrosion map in aqueous environments

For the erosion of alloys under aqueous conditions, there have been some recent attempts to identify the transitions between the erosion-corrosion regimes using laboratory results. Such transitions can be superimposed on an erosion-corrosion map as a function of the main corrosion and erosion variables. Defining the magnitude of the wastage rate on such maps enables the relevant process parameters involved in the damage process to be optimized. The object of this work was to model the erosion-corrosion behaviour of mild steel exposed to an aqueous solution containing alumina particles. The results were used to identify the transitions between the erosion-corrosion regimes on erosion-corrosion mechanism maps. Process control maps, which show the magnitude of the wastage rate, were also constructed using such an approach. This paper describes the basis of the mathematical models used to construct the boundaries on the maps. The effects of particle size, flux, and solution pH on such boundaries are demonstrated. In addition, a qualitative comparison is made between the results of the model, and a series of slurry erosion-corrosion tests of mild steel in aqueous media. (C) 1997 Elsevier Science S.A.