Abstract
The study aims to describe interactions between deuterium and deformation defects in austenitic stainless steel. Solution annealed 316L was pre-strained by uniaxial tension at 10, 20 and 31% or not strained. Dislocation density as a function of the pre-strain level was evaluated by X-ray diffraction (XRD). Cathodic charging was employed to introduce deuterium into the material as a tracer for hydrogen. Deuterium and deformation defects interactions were analyzed using thermodesorption spectrometry (TDS), secondary ion mass spectroscopy (SIMS) depth profiling, and numerical resolution of diffusion/trapping equations on samples that were subjected – or not – to aging treatment after charging. TDS thermograms showed that for all pre-strained samples a specific desorption peak appeared, which was assigned to deuterium trapping. Moreover, it was shown that the trap sites retained deuterium in the material and limited its desorption during aging treatment. Numerical simulations allowed to give a first estimation of the detrapping kinetic constants and highlighted a rather high detrapping energy that could be associated with strong trapping at dislocations cores or point defects.