RESUMO
Graphene coatings developed by chemical vapor deposition (CVD) that possess extraordinary/unique characteristics as barrier against aggressive environment can improve the corrosion resistance of Ni and Cu by up to two orders of magnitude. However, because of some compelling technical reasons, it has thus far been a nontrivial challenge to develop graphene coatings on the most commonly used engineering alloy, mild steel (MS). To circumvent the challenge simply by first electroplating MS with a Ni layer is attempted, and then developing CVD graphene over the Ni layer. However, this approach proved too simplistic and does not work. This necessitated an innovative surface modification of MS (based on basic metallurgical principles) that enabled successful CVD of graphene coating on MS. The graphene coating thus developed is demonstrated to improve the corrosion resistance of mild steel by two orders of magnitude in an aggressive chloride solution, through electrochemical testing. This improvement was not only sustained for the entire test duration of >1000 h; but there is a clear trend for the resistance to be possibly everlasting. The optimized surface modification that enabled development of CVD graphene coating on mild steel is generic in nature, and it should enable graphene coating on other alloy systems, which would otherwise not be possible.