Avaliação do comportamento à fadiga, corrosão e desgaste do aço estrutural ABNT 8620 revestido por diamond like carbon

Abstract

The increasing search for high performance materials, with high mechanical strength, corrosion resistence, thermal stability and durability has intensified in recent years, aimed at improving industrial systems. Fatigue, corrosion and wear are still the main degradation phenomena responsible for the mechanical failure of components. In this context, the application of a diamond like carbon film (DLC) coating on steel is presented as a promising approach to increase the life time of components and equipment and reduce overall costs in various industries due to its outstanding mechanical and physicochemical properties. In this work the coating was achieved by physical vapor deposition (PVD). The electrochemical behavior of the system was assessed by electrochemical impedance spectroscopy and by the anodic polarization method. The tribological behavior was evaluated by pin on disk and rotating bending fatigue essays.Considering this approach, the aim of this study was to evaluate the influence of the DLC deposition on ABNT 8620 steel as an alternative for the extension of equipment life in nuclear power plants. The morphology and physico-chemical characterizations of the surfaces of ABNT 8620 steel, coated with DLC or not were evaluated by profilometry, scanning electron microscopy, atomic force microscopy, Raman and dispersive energy spectroscopies. The results showed a reduction in the coefficient of friction after the DLC film deposition on the steel surface. There was also a failure in the coating with a load of 5 N, with abrasive and adhesion wear being predominant in all tribosystems analyzed. Furthermore, a higher corrosion potential and the charge transfer resistance were observed on the coated material. The use of the coating on ABNT8620 steel has shown promise for applications in structures and components in the nuclear sector