Berlin 2024 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
MM: Fachverband Metall- und Materialphysik
MM 23: Topical Session: Hydrogen in Materials: from Storage to Embrittlement III
MM 23.4: Vortrag
Dienstag, 19. März 2024, 12:45–13:00, C 130
The role of manganese and aluminium on hydrogen trapping and diffusion in Mn/Al rich steel alloys — Bikram Kumar Das1, •Mauricio Bonilla1, Poulami Chakraborty1, and Elena Akhmatskaya1,2 — 1BCAM - Basque Center for Applied Mathematics, Bilbao, Spain — 2IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
Hydrogen-induced embrittlement (HIE) remains a serious bottleneck for using steel in infrastructure for H2 storage and transport. Small amounts of Al and Mn have been shown to mitigate HIE, but the proposed mechanisms are often contradictory. To address this problem, we present a systematic approach to model the local environments (LEs) around the H-binding sites in FCC Fe-Mn-Al alloys up to the 3rd nearest neighbor (NN) shell. First, the most favorable LEs are determined using Density Functional Theory (DFT). Then, the local impact of Al/Mn content and distribution on the binding and diffusion of H is examined through the nudge elastic band method and crystal orbital Hamilton population analysis. We found that H-binding correlates most strongly with Al content, and is weakly influenced by Mn up to 5 wt%. Moreover, direct H-Al bonding destabilizes H binding, but the presence of Al in the 2nd NN shell of the H-binding site leads to a strong stabilizing effect by promoting H-Fe bonding. The presence of Al and Mn in grain boundaries and precipitates is known to play a prominent role in HIE. Here, we show that Al ability to indirectly trap H in bulk austenite could mitigate HIE. The analysis approach in this work could readily be adapted to study similar alloy systems.
Keywords: Hydrogen embrittlement; Austenitic Steel; Manganese Aluminium Alloys; Density Functional Theory; Crystal Orbital Hamilton Population