Effect of vacuum on the plastic zone around a fatigue crack in armco iron

Controlling factors and mechanisms of fatigue crack growth influenced by high pressure of gaseous hydrogen in a commercially pure iron

“…2. Once the mechanical loading is raised, intense slip deformation of the crack tip causes crack tip blunting accompanied by plastically deformed zone ahead of the crack tip in vacuum, but also at a lower extent in air and nitrogen (Figure 3 (a-2)) [56,57], leading to the formation of ductile striations [58]. In contrast, in the presence of hydrogen, the solute hydrogen atoms concentrated at the crack tip, for instance in high hydrostatic stress field [59], inhibit the plastic deformation at the crack tip.…”