Influence of deformation on the hydrogen behavior in iron and nickel base alloys: a review of experimental data

Most of the hydrogen-induced crack propagation mechanisms occuring in metals and alloys involve various interactions of hydrogen with deformation processes in materials. Modeling the kinetics of hydrogen entry with respect to its local concentration to assess a crack propagation rate first requires a detailed characterization of these interactions. The purpose of this paper is to review some data illustrating the influence of deformation on the hydrogen behavior in iron and nickel base alloys. Experimental data on hydrogen, deuterium and tritium diffusion and trapping show: (a) a strain dependence of the hydrogen ingress in b.c.c. alloys through natural or passive films; (b) a strain induced hydrogen trapping; (c) an accelerated transport of hydrogen in pre-strained samples or during dynamic straining; (d) a hydrogen enhanced localized plasticity; and (e) a deformation enhanced embrittlement. These effects are shown to depend on various parameters including the hydrogen activity, the material chemistry and microstructure, the strain rate and the temperature.