| Abstract Scope |
It is well-known that hydrogen affects plastic deformation processes in structural metals, but detailed understanding of how these effects depend on hydrogen concentration remains limited. The objective of this study is to address this knowledge gap by systematically evaluating the effect of hydrogen concentration on the work hardening behavior of polycrystalline, commercially pure nickel. Specimens were gaseously precharged with hydrogen concentrations of 0, 2000, 3000, 4000, and 5000 appm and then subjected to uniaxial tensile testing at ambient temperature. Experimental data are then assessed in the context of existing dislocation density-based hardening models. Results of this analysis reveal that there is an appreciable increase in dislocation storage as the hydrogen concentration is increased from 0 to 2000 appm, but minimal further increase beyond 2000 appm. Conversely, dynamic recovery behavior remains constant up to 3000 appm, but further increases in hydrogen concentration induce a significant acceleration in dynamic recovery. |