Influence of supersaturated carbon on the diffusion of Ni in ferrite determined by atom probe tomography

In patented and cold-drawn pearlitic steel wires dissociation of cementite occurs during mechanical deformation. In this study the influence of the carbon decomposition on the diffusion of nickel in ferrite is investigated by means of atom probe tomography. In the temperature range 423–523 K we observed a much smaller activation energy of Ni diffusion than for self-diffusion in body-centered cubic iron, indicating an increased vacancy density owing to enhanced formation of vacancy–carbon complexes.