Berlin 2024 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 26: Topical Session: Hydrogen in Materials: from Storage to Embrittlement IV
MM 26.3: Vortrag
Dienstag, 19. März 2024, 14:00–14:15, C 130
Hydrogen redistribution during electrochemical charging and mechanical testing: insights from a combined ab initio and finite element method — Christian Posch-Peperkorn1, Philipp Hammer1, Vsevolod Razumovskiy1, Werner Ecker1, Klemens Mraczek2, Ali Tehranchi3, and •Tilmann Hickel4 — 1Materials Centre Leoben Forschung GmbH, Austria — 2voestalpine Stahl GmbH, Linz, Austria — 3MPI für Eisenforschung Düsseldorf, Germany — 4Bundesanstalt für Materialforschung und -prüfung, Berlin, Germany
In advanced high strength steels the mechanisms of hydrogen embrittlement are expected to be strongly connected to the amount of retained austenite (RA) contained in the microstructure and its transformation upon deformation. We have developed a multi-scale model for the H redistribution during H charging and tensile loading within a martensitic/austenitic microstructure. Ab initio simulations have been used to resolve the complex energy profile of H in the phase boundaries. Representative microstructures with different amounts of RA have been converted form experimental SEM-EBSD measurements. Simulations with the finite element method (FEM) have been used to analyse H concentration profiles. The simulations confirm an accumulation of H within the austenitic phase during charging, which undergoes a phase transformation under mechanical load and releases accumulated H into the martensite matrix. The latter segregates to the microstructure regions subjected to high hydrostatic tensile stresses and plastic strains, driving H embrittlement.
Keywords: ab initio; FEM simulation; retained austenite; hydrogen embrittlement