Abstract

The present study aims to characterize microstructurally and evaluate the electrochemical behavior of Vecalloy B® and Alpha Plus®+SS420 metallic coatings deposited by thermal spraying using the electric arc technique. For the microstructural caracterization of the coatings, X-ray diffraction (XRD), optical microscopy (OM) and scanning electronic microscopy (SEM) techniques were used. Regarding the electrochemical behavior, potentiodynamic polarization tests were carried out, as well as electrochemical impedance spectroscopy tests. From the microstructural characterization, it was found that both coatings are mainly composed of lamellae, pores, oxides and unmolten particles. In the electrochemical tests, it was found that Vecalloy B coating has a higher resistance against corrosion by presenting a lower corrosion current density and nobler corrosion potential compared to Alpha Plus+SS420 coating, this probably due to a lower porosity and to the presence of some alloying elements that have a higher resistance against electrochemical attacks.