Corrosion Behaviour of Nickel Coated AISI 316 Stainless Steel as a Function of Annealing Temperature

AISI 316 stainless steels were coated with 250 nm Ni film by electron beam deposition and post-annealed at different temperatures with a nitrogen flow of 600 cm3min-1 nitrogen. The prepared samples were corrosion tested in 1.0 M sulphuric acid solution using potentiodynamic technique. Crystallographic and morphological structure of the samples were analyzedanalysed by X-ray diffraction (XRD) and atomic force microscopy (AFM) respectively before corrosion test, and scanning electron microscope (SEM) after corrosion test. A clear correlation between the physical analyses (XRD, AFM and SEM) and the potentiodynamic results was is achieved. It is found that both surface roughness and the annealing temperature have important role on corrosion resistance performance of the samples produced in this work and the optimum results can be obtained at annealing temperature of 623 K for AISI 316 samples where both surface roughness and temperature (diffusion effect) have reached their critical values.