CLEAVAGE ANNULAR STRESS PRODUCING FRACTURE PATH DEFLECTION IN COLD DRAWN PEARLITIC STEELS

摘要

In this paper a study of fracture behaviour of prestressing pearlitic steel with different cold drawing degree is performed, focussed on the samples that show an anisotropic fracture behaviour in a special manner, i.e., those samples that have a fracture surface onto a plane clearly different from the transversal plane of the sample's longitudinal axis. The studied samples belong to all the intermediate stages of the real manufacture chain of the cold working process: the initial hot rolled bar (not cold drawn at all) and the final commercial product (prestressing steel wire). Testing samples have a circumferentially shaped notch with different values of radius and deep in the wires, in order to achieve very distinct constraint levels (triaxiality) and fracture behaviours.