Relative thermodynamic stability of martensite and austenite near the room temperature

Chemical potentials of the components of quenched Fe-Ni alloys (28.7-32.7 at. % Ni) with martensite and austenite structures have been found with the Touch Instant Electromotive Force Method. Differences of their Gibbs energies that are a measure of relative thermodynamic stability of metastable martensite and austenite at the temperature range of 253-315 K have been calculated. The T$_0$* temperatures at which Gibbs energies of alloys with both types of structures are mutually equal have been determined by interpolation. The “non-chemical" contribution into Gibbs energy of the martensitic transformation has been evaluated