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. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.