Nanostructure and torsional ductility of Heavily Cold Drawn Steel Wires

A three dimensional knowledge of the atom-scale structure is necessary for improving the design and understanding of the modem materials. Atom probe is used to obtain atom by atom 3D reconstruction to characterize three versions of carbon in pearlitic steel wires. Since steel wires are subjected in heavy drawing amounts, the carbon atoms in cementite lamellae moved into ferrites lamellae. It is worthy to find the influence of the cementite dissolution on the mechanical properties, especially torsional ductility. The steel wires were fabricated depending on the carbon content of 0.82 and 1.02 wt.% and drawing condition of 4.12 to 4.32. The atom probe assisted with laser was used to identify the cementite dissolution in steel wires. As carbon content and drawing strain increased, the cementite dissolution occurred actively, resulting in the difference of torsional behavior. The effects of the cementite dissolution on the torsional behavior of high carbon steel wires have been discussed.