The alloying effects of Mn, Co and Nb on the stacking fault energy of austenitic stainless steels, Fe–Cr–Ni with various Ni contents, were investigated via quantum–mechanical first-principles calculations. In the composition range (cCr = 20%, cNi between 8 and 20%, cMn greater than 0, cCo and cNb less than 8%, balance Fe) studied here, it was found that Mn always decreased the stacking fault energy at 0K but increased it at room temperature in high-Ni (cNi greater than 16%) alloys. The stacking fault energy always decreased with increasing Co content. Niobium increased the stacking fault energy significantly in low-Ni alloys; however, this effect was strongly diminished in high-Ni alloys. The stacking fault energy-enhancing effect of Ni usually observed in Fe–Cr–Ni alloys was inverted to an stacking fault energy-decreasing effect by Nb for cNb greater than 3%. The revealed nonlinear composition dependencies were explained in terms of the peculiar magnetic contributions to the total stacking fault energy.

Stacking Fault Energies of Mn, Co and Nb Alloyed Austenitic Stainless Steels. S.Lu, Q.M.Hu, B.Johansson, L.Vitos: Acta Materialia, 2011, 59[14], 5728-34