Stacking fault energies of Mn, Co and Nb alloyed austenitic stainless steels

• Published in: Acta materialia Vol. 59; no. 14; pp. 5728 - 5734
• Main Authors: Lu, Song, Hu, Qing-Miao, Johansson, Börje, Vitos, Levente
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.08.2011; Elsevier
• Subjects: Alloy steels; Alloying effects; Applied sciences; Austenitic stainless steels; Exact sciences and technology; First-principles electron theory; Mathematical analysis; Metals. Metallurgy; Nickel; Niobium base alloys; Stacking fault energy; Steels; Stacking fault energy; Austenitic stainless steels; First-principles electron theory; Austenitic stainless steel; Austenitic steel; Stainless steel; Stacking fault
• ISSN: 1359-6454; 1873-2453; 1873-2453
• DOI: 10.1016/j.actamat.2011.05.049

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