The electrochemical corrosion behavior of high purity iron, nickel, and chromium is evaluated in sodium sulfate solutions at temperatures up to 473 K. The thermodynamic stability regions of the species involved in the X-H2O system (X = Fe, Ni, Cr) were evaluated. The stability regions were presented in a new form of potential vs. temperature diagrams in specific solutions rather than conventional E-pH diagrams. The open circuit potential and polarization resistance experiment data were used to demonstrate the viability and usefulness of the newly developed diagrams. (C) 2013 Elsevier Ltd. All rights reserved.