Identification of transitions in erosion-corrosion regimes in aqueous environments

Wastage of materials due to the synergistic effects of erosion and corrosion occurs in both ''dry'' and ''wet'' industrial processes. In the ''dry'' case, degradation occurs due to the impact of solid particles on corroding surfaces at elevated temperatures. In the ''wet'' case, wastage is due to the impact of solid particles in aqueous media or other reactive liquids.

A distinctive difference between the investigations in these two research areas is in the various attempts made to assign ''regimes'' of behaviour. In the ''dry'' high temperature studies, there have been attempts to define possible regimes of behaviour. However, in the ''wet'' environments, this has not generally been the case.

This paper describes the initial results from an experimental programme which aims to identify and explain transitions in erosion-corrosion ''repimes'' at room temperatures, for pure metals and alloys. It will be shown how such results can be used to define erosion-corrosion regimes in such environments, which has not been attempted to date. In addition, an aqueous erosion-corrosion map is proposed where the transitions between the aqueous erosion-corrosion regimes is given as a function of erodent velocity and potential.