Cryogenic ductile and cleavage fracture of bcc metallic structures – Influence of anisotropy and stress states

The anisotropic cryogenic ductile and cleavage fracture properties of a body-centered cubic (bcc) steel at −196°C have been investigated under broad spectrum loading conditions, crossing stress triaxiality range from −1/3 to 1.5, along three directions. Fracture is completely impeded in uniaxial compression tests. Conventional brittle behavior only observed high conditions for the bcc steel, on contrary with shear void coalescence as underlying mechanisms takes place low (simple shear) moderate (uniaxial tension) −196°C. Cleavage occurs after significant plasticity during tensile tests using flat-notched specimens plane-strain tension. For all states, anisotropy has shown profound influence fracture, and, particularly transition region mixed two failure types. It concluded that reason activated states because strain hardening capacity, Lankford coefficients, initiation well strength are dependent orientations. Based collected local critical variables finite element simulations an evolving model, unified criterion revealing developed demonstrates distinguished predictive capability describing different