The structure and properties of drawn pearlite

The microstructures of drawn, coarse and fine pearlite have been examined by transmission and replica electron microscopy. The observations indicate that a cellular dislocation substructure is developed during drawing and that the mean distance between substructural barriers measured perpendicular to the wire axis decreases continuously with increasing strain.An empirical model has been developed to relate the flow stress of the drawn wire to the spacing of substructural barriers in terms of the drafting strain. Qualitative evidence is presented which indicates that this type of strengthening mechanism is operative in the case of drawn iron wire of commercial purity. Some observations on the plastic deformation and fracture of cementite are also included.