Avaliação do efeito dos parâmetros de eletrodeposição sobre as propriedades de resistência a corrosão e permeação por hidrogênio no aço SAE 1020 revestido com a liga Zn-Ni.

Abstract

The objective of this study was to evaluate the influence of nickel content in zinc-nickel coatings on hydrogen retention and permeability through a low-carbon steel. A modified electrochemical desorption method was employed to quantify hydrogen adsorption on the coatings, and the hydrogen permeation behavior was analyzed using a dual-cell electrochemical setup. The morphology and chemical composition of the coatings were characterized by scanning electron microscopy and X-ray diffraction. The results indicated that increasing the nickel content in the coating refined the grain structure and increased the corrosion resistance. Electrochemical impedance spectroscopy tests confirmed the results obtained by linear polarization resistance tests. A significant decrease in hydrogen permeability was observed for the intermediate composition of 17.27 wt% Ni, suggesting a synergistic effect that increased irreversible hydrogen trapping. Furthermore, a gradual decrease in apparent hydrogen diffusivity was observed as the nickel content in the coating increased. This suggests the development of more resistant barriers to the diffusion process. These findings highlighted the strong influence of nickel composition on the quality of the obtained coatings, indicating the importance of optimizing the alloy composition to improve the resistance to hydrogen embrittlement in steel substrates.