Fig. 5. H induced cracking and failure associated with TBs in H-charged sample.

a Orientation map obtained by EBSD on the sample surface after SSRT to failure; b a magnified image from (a) showing long cracks associated with TBs, which are indicated by black arrows, and Schmid factor of the TBs are noted; c the corresponding secondary electron image of (b) with dislocation slip bands (DSBs) indicated; d–f more magnified images from the framed regions in (a) to show cracks along relatively short TBs and extended to the neighbouring grains; The inset in (b) is the colour legend of all orientation maps. g A SEM image of the fracture surface showing very flat facets in the quasi-cleavage regions, where H was present during SSRT.