Corrosion and salt scale resistance of multilayered diamond-like carbon film in CO2 saturated solutions

Tribocorrosion evaluation of hydrogenated and silicon DLC coatings on carbon steel for use in valves, pistons and pumps in oil and gas industry

“…Literature [20,21] shows that the interlayer WC and H forms a non-stoichiometric hydrogenated tungsten carbide WC:H, also known as W-C:H or as W-DLC. Literature [5,8,14,17,22] shows that the Raman spectrum of the coating has two types of C-C bonding structure, where diamond-like (sp 3 -D band) is found between 1200-1450 cm -1 and graphite-like structure (sp 2 -G band) between 1500 -1700 cm -1 . Si-DLC, respectively.…”

“…However, when increased the contact pressure occurred detachment of the coating (Figure 4 [1,5] . Wang et al [5], claim that if there is a failure on the surface of the DLC film exposing the metal surface, the localised corrosion could be easily inhibited by virtue of the DLC film and carbon steel have almost the same OCP. Consequently, the H-DLC provide a good improvement on the integrity against internal corrosion in carbon steel,…”

“…However, polymeric coatings lack hardness and can be degraded. Because of this, DLC coatings could be applied on internal parts of pipelines providing good corrosion resistance for oil and gas applications [5,6]. DLC coatings are designed to have a combined resistance to wear and corrosion in automotive and biomedical areas [7][8][9][10][11][12][13].…”

“…However, the main results in the literature are associated with defects and microstructure. Only few papers have been postulated to corrosion resistance for DLC coatings [1,2,5,14,17].…”

“…There are several studies related to tribocorrosion of stainless steel coated with a-C:H films. However, literature reporting the combined effect of the tribological conditions in a corrosive medium for a-C:H and a-C:H:Si using carbon steel as a substrate is scarce [1,2,5,[7][8][9]14,17]. The behaviour of these materials subjected to tribocorrosion can be very complex owing to many parameters involved in the process, but sliding testing simultaneously with the use of electrochemical techniques could contribute to better understand the deterioration effect that takes place.…”