A first-principles study on the hydrogen trap characteristics of coherent nano-precipitates in α-Fe

Autor: Lijie Qiao, Ma Yuan, Lei Gao, Yufang Shi, Heyuan Wang, Zhishan Mi, Z.Y. Liu, Yanjing Su, Yu Yan
Rok vydání: 2020
Předmět:
Zdroj: International Journal of Hydrogen Energy. 45:27941-27949
ISSN: 0360-3199
DOI: 10.1016/j.ijhydene.2020.07.123
Popis: Density functional theory (DFT) calculations have been carried out to investigate the hydrogen trap characteristics of a serial of nano-precipitates (VC, VN, TiN, NbN, NbC, and NiAl) in α-Fe. The H atom solution energies calculations in bulk nano-precipitates indicate that ideal nano-precipitates could not trap H atoms, while the vacancies in nano-precipitates could reduce the H atom solution energies. With respect to the coherent interfaces between α-Fe and nano-precipitates, tetrahedral sites are possible hydrogen traps. Volume evolutions and Bader charge analyses have been performed and it was found the strain at the coherent interface benefits to the hydrogen trap. In addition, the vacancies near the coherent interfaces could be fine hydrogen traps, which is attributed to the combined effect of strain and vacancy. This study could provide guidance to design nano-precipitates in steel to suppress the hydrogen embrittlement.
Databáze: OpenAIRE