fig7
Figure 7. Mechanism and prediction of HE in various alloy systems. (A) Schematic of embrittlement process at crack tip. (B) Schematic of crack tip hydrogen concentrations Ccleave and Cemit that control embrittlement as a function of KIapp. (C) Predicted embrittlement due to nanodiffusion and blocking of dislocation emission: KIapp reaches KIC prior to reaching KIe. (D) Predicted embrittled and unembrittled domains of hydrogen concentration for six alloys and Ni. The transition region corresponding to the upper and lower limits of KIe is indicated by thick black lines (Reproduced with permission[68]. Copyright 2021, American Physical Society). HE: Hydrogen embrittlement.