CONSTRUCTION OF EROSION-CORROSION MAPS FOR EROSION IN AQUEOUS SLURRIES

Although much research has been carried out on the erosion of material s in aqueous slurries, little attention has been given to defining tra nsitions between erosion regimes in such environments. This is despite the large amount of work that has been carried out in this area in 'd ry' high temperature corrosion environments. Defining transitions betw een regimes permits distinction between erosion and corrosion dominate d behaviour which can be an aid to materials selection and to process monitoring in such conditions. This paper describes the basis of a rel atively simple theoretical method for evaluating the transitions betwe en erosion and aqueous corrosion regimes. Models for solid particle er osion at normal impact are combined with those for aqueous corrosion t o define regimes of damage in corrosion conditions varying from dissol ution to passivation. This permits the construction of the erosion-aqu eous corrosion map where the transitions between the regimes are shown as a function of erosion and aqueous corrosion variables. The rationa le for the regimes suggested is discussed on the basis of research on erosion maps in oxidising conditions. The boundaries on the maps are c ompared with experimental data. Other issues addressed in this study i nclude using the erosion-corrosion map to identify favourable and adve rse operating conditions in addition to identifying the mechanism of d amage. (C) 1996 The Institute of Materials.