Microstructure-based modelling of fracture in progressively drawn pearlitic steels

The fracture process of progressively drawn steels is studied. Results show that drawing affects the phenomenon, so that heavily drawn steels exhibit anisotropic fracture behaviour. A micromechanical model of fracture is proposed to rationalize the results on the basis of the microstructure of the steels after drawing. In slightly drawn steels, the Miller–Smith model of shear cracking in pearlite may be adequate to describe the fracture process. In heavily drawn steels, a fracture propagation step appears, and it may be caused by extremely slender pearlitic pseudocolonies aligned in the drawing direction, with anomalous (very high) local interlamellar spacing which makes them preferential fracture paths with minimum local resistance.