Use of the phase stability and kinetic diagrams in relation to the high temperature oxidation of binary solid-solution alloys

After considering briefly the phase diagrams of ternary systems involving two metal components and one oxidant and the limitations to their use in relation to the high temperature oxidation of binary alloys, the paper examines the construction of other plots, denoted as kinetic diagrams, useful to predict under which conditions the two oxides, assumed to be mutually insoluble, can form the external scale during the high-temperature oxidation of binary alloys. The kinetic diagrams are calculated on the basis of a complete set of data of a thermodynamic and kinetic nature concerning both the alloy and the oxides, assuming the validity of the parabolic rate law. The combined use of the two types of diagram provides more complete information about the oxidation behavior of binary alloys.