Fundamental criterion Ktrans for failure analysis of hydrogen-assisted cracks in notched specimens of pure Ni

The effects of short notches on crack initiation and extension were studied under electrochemical hydrogen charging in pure nickel. In the hydrogen-charged smooth specimen, multiple cracks were initiated on grain boundaries after significant plastic deformation and were subsequently arrested by crack blunting in the interior of neighboring grains. With the assistance of sub-cracks on specimen surface, quasi-cleavage crack propagation occurred...