Hydrogen embrittlement susceptibility of prestressing steel wires: the role of the cold-drawing conditions

Abstract

Prestressing steel wires are highly susceptible to hydrogen embrittlement (HE). Residual stress-strain state, produced after wire drawing, plays an essential role since hydrogen damage at certain places of the material is directly affected by stress and strain fields. Changes in wire drawing conditions modify the stress and strain fields and, consequently, the HE susceptibility and life in service of these structural components in the presence of a hydrogenating environment. This paper analyzes the distributions of residual stress and plastic strain obtained after diverse drawing conditions (inlet die angle, die bearing length, varying die angle and straining path) and their influence on HE susceptibility of the wires. The conditions for industrial cold drawing can thus be optimized, thereby producing commercial prestressing steel wires with improved performance against HE phenomena.