Fracture of a 08KP steel in nano-fragmented state

The evaluation of the resistance to the fracture toughness of metals and metal composites that work in the plastic regime requires of the using of highly complex experimental methods and analysis which are not at all standard ones. The increment in the parameters describing the mechanical properties is certainly associated to the origin of internal barriers inside the material which are capable of stopping the free movement of the dislocations and their packing on specific sites of the crystalline structure. The dislocations play an important role on the transmitted energy in the metal during the deformation process. In this work it is analyzed the cryogenic hardness mechanism by deformation, and the features which influence such mechanism. The effectiveness of the hardness treatment of the metal is determined by the two factors: 1) the capacity of the dislocation barrier in order to support the stress between dislocations; 2) the distance between the barriers. In this work, the capacity of the barriers for stopping the dislocations is determined measuring the stress over them.