Hydrogen effects on the plasticity of face centred cubic (fcc) crystals

International audience; The dynamic interactions between solid solution hydrogen atoms and dislocations in face centred cubic (fcc) crystals are considered. Using strain ageing experiments, the strength of the elastic binding between dislocations and solutes atmospheres is measured. These results support the linearised hydrogen elasticity framework for modelling hydrogen-dislocation interactions. It is used to derive quantitative estimates of hydrogen effects on dislocation properties. Consequences are predicted on the Franck-Read mechanism and the cross-slip probability of screw dislocations. They are compared to the tensile response of nickel single crystals. Cross-slip is the mechanism whose alteration by hydrogen has the most important consequences on deformation. Effects on hydrogen-induced damage are discussed and possible extensions to other classes of metals and alloys are outlined.