%0 journal article
%@ 1359-6462
%A Pogrielz, T.,Eichinger, M.,Weiser, A.,Todt, J.,Hohenwarter, A.,Ascii, A.,Sarac, B.,Brandl, D.,Ressel, G.,Jary, M.,Dlouhy, A.,Mori, G.,Keckes, J.
%D 2024
%J Scripta Materialia
%N 
%P 116142 
%R doi:10.1016/j.scriptamat.2024.116142
%T Peculiarity of hydrogen absorption in duplex steels: Phase-selective lattice swelling and stress evolution
%U https://doi.org/10.1016/j.scriptamat.2024.116142
 
%X Electrochemical hydrogen absorption in duplex steels is not fully understood. In this work, an in-situ synchrotron cross-sectional X-ray micro-diffraction analysis is performed on steel with comparable phase fractions of ferrite and austenite, coupled with electrolytic hydrogen charging. The results reveal that charging with a constant current density of 10 mA/cm² for 5 h leads to expanding the austenitic lattice to a depth of approximately 250 µm, up to ≥0.15 %. In contrast, the lattice parameter of the ferrite phase remains unchanged during this process. As the austenite expansion progresses, it generates different amounts of equivalent in-plane compressive stresses, which amount to approximately -150 and -450 MPa in the austenite and ferrite phases at the sample surface, respectively. Using a finite element model of grain interaction, this difference is qualitatively interpreted by mutual mechanical constraints between ferrite and austenite, as well as between the hydrogen-charged surface layer and the underlying material.