Corrosion inhibition of AISI 316 stainless steel by Ni coating and subsequent annealing with flow of nitrogen at different temperatures

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