Contribution to the study of diffusion and localisation of hydrogen in extra-mild steel. Consequences on embrittlement

In this engineering research thesis, the author reports the study of solution and diffusion of hydrogen in Fe alpha, the study of the localisation of hydrogen in the iron lattice (radio-crystallographic study), the study of the hydrogen embrittlement under uniaxial traction (influence of loading time and of holding duration, influence of hydrogen on sliding properties, influence of hydrogen on fracture facies), the study of a prior strain hardening on hydrogen embrittlement (strain hardening at room temperature or liquid air temperature, fracture at room or liquid air temperature), and a discussion of the general process of hydrogen embrittlement.