Investigation of iron adsorption on composite transition metal carbides in steel by first-principles calculation

• Published in: The Journal of physics and chemistry of solids 2018-05, Vol.116, p.30-36
• Main Authors: Xiong, Hui-Hui, Gan, Lei, Tong, Zhi-Fang, Zhang, Heng-Hua, Zhou, Yang
• Format: Article
• Language: English
• Subjects: Adsorption energy; Composite transition metal carbides; First-principles calculation; Iron
• ISSN: 0022-3697; 1879-2553
• DOI: 10.1016/j.jpcs.2018.01.013

The nucleation potential of transition metal (TM) carbides formed in steel can be predicted by the behavior of iron adsorption on their surface. Therefore, Fe adsorption on the (001) surface of (A1-xmx)C (A = Nb, Ti, m = Mo, V) was investigated by the first-principles method to reveal the initialization of Fe nucleation. The Mulliken population and partial density of state (PDOS) were also calculated and analyzed in this work. The results show that Fe adsorption depends on the composition and configuration of the composite carbides. The adsorption energy (Wads) of Fe on most of (A1-xmx)C is larger than that of Fe on pure TiC or NbC. The maximum Wads is found for Fe on (Nb0.5Mo0.5)C complex carbide, indicating that this carbide has the high nucleation capacity at early stage. The Fe adsorption could be improved by the segregation of Cr and Mn atoms on the surfaces of (Nb0.5Mo0.5)C and (Ti0.5Mo0.5)C. The PDOS analysis of (Cr, Mn)-doped systems further explains the strong interactions between Fe and Cr or Mn atoms. [Display omitted] •Fe adsorption on the (001) surface of (A1-xmx)C (A = Nb, Ti, m = Mo, V) was investigated by the first-principles method.•The Wads value of Fe on most of (A1-xmx)C(001) is larger than that of Fe on pure TiC or NbC.•The maximum Wads value was found for Fe on the (Nb0.5Mo0.5)C complex carbide.•Segregation of Cr and Mn atoms on (A0.5Mo0.5)C surfaces improves the subsequent Fe adsorption.