Erosion-corrosion of materials in aqueous environments is a complex phenomenon involving a very large number of variables. In such cases, characteristics of the target, particle and the environment affect the degradation mechanism. Predicting material behaviour may sometimes be a "black art" due to the parameter size which is involved in such processes. In studies of erosion-corrosion, there have been significant advances in the modelling of such processes in recent years. Various methodologies employed include quasi-static modelling, using CFD modelling and erosion-corrosion mapping. In such cases, the output of the various models can differ significantly. In this work, a methodology combining CFD modelling and erosion-corrosion mapping has been developed to model erosion-corrosion behaviour of pure metals, which variously passivate and dissolve under a range of simulated conditions. This provides a means of mapping the component undergoing erosion-corrosion and thus is a step change on previous modelling work in this area as it enables superimposition of the erosion-corrosion map on real surfaces. The relative advantages and limitations of this approach are discussed in this paper