Etude et Caractérisation des Fils en Acier Dur Destinés pour la Fabrication des Torons.

Abstract

The main aim of this work is to study the evolution of the texture in the ferrite phase during plastic deformation by drawing pearlitic steel wires of grade (C82D) intended for manufacture of strand wires, and more generally to undertake a correlation between the microstructure and the behavior of these steel wires under mechanical stress. Wire drawing induces the development of the density of dislocations, the reduction of the interlamellar spacing and the refinement of grains sizes which leads to a strong hardening of the wires. This explains the increase in tensile strength from 1242 MPa to 2618 MPa with higher strain. In addition, the cementite lamellae are turned towards the wire drawing axis and the thickness of the lamellae decreases further when the level of deformation increases, this phenomenon leads to a somewhat fibrous structure. The quantitative analysis of the texture obtained by EBSD data shows the development and reinforcement of a <110> fiber texture over the entire section of the drawn wire (center and surface). A variety of experimental measurement and characterization techniques have made it possible to carry out this work. These are scanning electron microscopy (SEM/EDX), X-ray diffraction, backscattered electron diffraction (EBSD), tensile and torsion tests and microhardness measurements, some of which have made it possible to correlate the microstructure to the mechanical properties.