| Abstract Scope |
The Pourbaix diagram, or potential-pH diagram, is an electrochemical phase diagram which represents the thermodynamically predominant reaction products in aqueous corrosion. In this talk, two recent advances in the calculation of Pourbaix diagrams using the CALPHAD approach will be discussed for aqueous corrosion studies. First, a room temperature Pourbaix diagram considering oxide solid solutions, as a generalization of the traditional Pourbaix diagram with stoichiometric oxides, is constructed for an FCC single-phase high entropy alloy. By incorporating the solution models of complex oxides, this work presents a general and more accurate way to analyze the reaction products during aqueous corrosion of high entropy alloys. Second, a thermodynamic probability diagram is calculated to analyze the effects of Rb on the corrosion susceptibility of Cr-containing steels for nuclear materials canisters, which avoid the all-or-nothing approach to oxide formation typical of Pourbaix diagram. The formation of metastable species can be analyzed in aqueous environments. |