Anisotropic Fatigue Fracture Behaviour in Hot-Rolled and Cold-Drawn Pearlitic Steel Wires

摘要

This paper analyses the role of cold drawing in the fatigue and fracture behaviour of pearlitic steels with distinct drawing degree (a hot rolled bar and a commercial prestressing steel wire). Fatigue crack growth develops globally in mode I and locally in mixed mode in both steels, the micro-crack deflection angle depending on the drawing degree. With regard to fracture behaviour, it takes place in mode I in the hot-rolled bar and in mixed mode (with a strong component of mode II) in the case of the cold-drawn wire, so that strength anisotropy appears in the drawn steel and a sort of directional toughness can be defined.