Effects of Alloying Elements, Si and Cr, on Aging and Delamination Behaviors in Cold-Drawn and Subsequently Annealed Hyper-eutectoid Steel Wires

The effects of alloying elements, Cr and Si, and the conditions of hot-dip galvanizing on the aging behaviors and their related tensile and torsional properties in cold drawn hyper-eutectoid steel wires were investigated. The Cr and Si additions were found to increase tensile strength, but decrease the limit of drawing strain without delamination in cold drawn steel wires. The Cr and Si additions encouraged the suppression of age hardening and age softening during annealing. The increased amount of deformation in cold drawn steel wires made age hardening occur at the lower annealing temperature and shorter annealing time, and expanded the delamination region to high temperature during annealing. The additions of Cr and Si did not show the noticeable improvement of tensile strength without delamination in cold drawn steel wires, but increased the upper limit of tensile strength without delamination in cold drawn and annealed steel wires.