Dislocation structures in 16MND5 pressure vessel steel strained in uniaxial tension

Cylindrical specimens of bainitic pressure vessel steel 16MND5 were strained in uniaxial tension at liquid nitrogen temperature. Dislocation structures and surface relief were studied at 2.5% and 8% of plastic deformation and their evolution with increasing plastic strain is documented. The knowledge of dislocation arrangements is the starting point to model the local stress states that can result in cleavage initiation.