Thermodynamic modeling of the stacking fault energy of austenitic steels

The stacking fault energies (SFE) of 10 austenitic steels were determined in the temperature range 50 ⩽ T ⩽ 600 K by thermodynamic modeling of the Fe–Cr–Ni–Mn–Al–Si–Cu–C–N system using a modified Olson and Cohen modeling approach (Olson GB, Cohen M. Metall Trans 1976;7A:1897 [1]). The applied model accounts for each element’s contribution to the Gibbs energy, the first-order excess free energies, magnetic contributions and the effect of interstitial nitrogen. Experimental SFE values from X-ray diffraction measurements were used for comparison. The effect of SFE on deformation mechanisms was also studied by electron backscatter diffraction.