Improved cold-drawn eutectoid steel wires based on residual stress measurement and simulation - Part 1: residual stress characterization

摘要

Knowledge of residual stresses can be used to improve the performance of drawn wires. In this first part, residual stress characterization is examined: difficulties, limitations and interpretation of the measurements. Cold-drawn eutectoid steel wires can be seen as, in present day terminology, nano-composite, nano-laminate material (of alternating ferrite and cementite lamellae) with outstanding properties of strength and toughness. They are the active tendons in prestressed concrete structures, support the tensile stresses in suspension and stayed bridges, form the cables in mine shafts and off-shore petroleum production and act as very fine wires for tire reinforcement in cars. With modern computational techniques it is possible to estimate the stresses to which the wires would be subjected in service. However, this could not be enough to predict the performance of the wires because the presence of residual stresses, which will be added to the service stresses, can seriously affect the life of the component1. It is shown, for example, that tensile residual stresses at the surface of the wires produce deleterious effects in stress corrosion cracking or fatigue.