Corrosion Inhibition of AISI 304 Stainless Steel using Zinc Nitride Coating

The corrosion behavior of Zn/ (AISI304) annealed at different temperatures with flow of nitrogen gas was investigated in the 3.5%NaCl solution. Crystallography structure of the samples was analyzed using X-ray diffraction (XRD) pattern. The results showed that with increasing annealing temperature, the intensities of oxide and nitride phases were increased. Surface morphology of the samples was studied using atomic force microscope (AFM) before corrosion tests. AFM results showed that by increasing annealing temperature, grains become greater that may be the result of heat accumulation, causing higher rate of diffusion in the sample. Electrochemical Impedance spectroscopy (EIS) and Polarization tests were carried out for corrosion resistance investigation of the produced samples. The corrosion results revealed that highest corrosion resistance was achieved for the sample at the highest annealing temperature. For more in depth analysis, the equivalent circuit of samples was obtained, using the EIS data. Finally, the surface of the corroded samples was observed using scanning electron microscopy (SEM).