Tailoring stress corrosion cracking resistance of pearlitic steel wires via composition and cold drawing ratio

High-strength pearlitic steel wires are critical for enhancing the load-bearing efficiency of bridge structures. However, increased strength often comes at the cost of greater stress corrosion susceptibility. This study investigated how composition and cold-draw ratio (CDR) influence the stress corrosion fracture of pearlitic steel wires with the same tensile strength. Increasing the carbon and silicon content in the steel wire refined the pearlite lamellar spacing from 81 nm to 27 nm, decreased the corrosion current density (i_corr) from 4.57 × 10⁻⁴A·cm² to 0.77 × 10⁻⁴ A·cm², decreased the proportion of reversible hydrogen traps from 92.9 % to 87.4 %, and increased the average time for stress corrosion fracture from 8.8 h to 66.4 h. In contrast, increasing the CDR from 75 % to 78 % (with similar compositions) reduced the lamellar spacing from 81 nm to 54 nm, decreased the corrosion current density (i_corr) from 4.57 × 10⁻⁴A·cm² to 2.45 × 10⁻⁴ A·cm², slightly decreased the reversible hydrogen traps from 92.9 % to 92.2 %, and increased the fracture time from 8.8 h to 18.7 h. These findings provided mechanistic insights into optimising composition and deformation processing to enhance the stress corrosion cracking resistance of pearlitic steel wires.