Residual stress determination in cold drawn steel wire by FEM simulation and X-ray diffraction

This paper presents a study on residual stress in cold drawn wire of low carbon steel by means of finite-element method (FEM) simulation and X-ray diffraction. A thick wire with a diameter of 17.9 mm drawn from an annealed wire with a diameter of 20.1 mm was investigated. First, FEM simulations were performed based on a suitable model describing the boundary conditions and the exact material behavior. Due to the initial texture in the original material, the anisotropy of the material plastic behavior was taken into account on the basis of the texture measurement of the wire. Instead of the isotropic von Mises yield criterion, a texture-based anisotropic yield locus was incorporated into the model to simulate the wire drawing process and calculate residual stresses. Next, X-ray diffraction measurements were carried out at the surface of the wire to obtain the distribution of the lattice spacing versus sin2 ψ, from which the macroscopic residual stresses at the wire surface were calculated. The comparison between the results from the simulations and the measurements shows that a good agreement has been reached.