Abstract
Steel samples coated by electroless nickel were annealed in air. Oxide growth kinetics and iron diffusion through the structure were investigated by glow discharge optical emission spectroscopy (GDOS) depth profiling. Protection against high‐temperature oxidation was found to be given mostly by the austenitic interdiffusion layer formed at the interface between the substrate and the NiP film during annealing of the sample, which acts as a diffusion barrier for diffusion of iron to the surface.