Residual stresses and durability in cold drawn eutectoid steel wires

Abstract

Prestressing steel wires have excellent mechanical properties but there is a need to improve their durability in aggressive environments. In this work, the influence of residual stresses on the environmentally assisted cracking of these wires is studied. A good correlation has been found between residual stresses at the surface of the wires and the time to rupture during stress corrosion test proposed by the International Federation of Prestressing. Wires with the same microstructure, surface quality and mechanical properties show very different behaviour in aggressive environments depending on their residual stress state. Research shows that environmentally assisted cracking can be improved significantly by acting on the surface residual stresses produced by wire drawing. In addition, in this study a post-drawing treatment to generate compressive residual stresses at the surface of the wires is proposed.