As mentioned above, the atomic hydrogen prefers to pileup in
the regions with high KAM values, as dislocation density of these
positions are high, it would increase the hydrogen traps. Then,
atomic hydrogen aggregates to generate hydrogen pressure and
result in the initiation of crack easily. The crack would form among
the grains with high Taylor factor and proceeds along the HAGBs
or across the LAGBs. The growth of cracking leads to the failure of
the S1 sample eventually. As a result, it can be used to assess and
predict crack initiation and propagation.