Promoting the corrosion resistance of carbon steel via facile catalytic deposition of novel hierarchical carbon film layer in an ethanol combustion flame

Abstract

In this work, a novel flame treatment method to improve the corrosion resistance of carbon steel was developed. With the method, a highly protective carbon film layer could be directly grown in situ on the surface of the nickel plating layer on the steel substrate and the whole deposition process costed only 10 min. Different from other carbon counterparts in literature, such as graphene deposited on Ni substrate with CVD, the as-fabricated carbon layer displayed a smooth surface but with a unique staggered interface with the Ni underlayer, which was reported for the first time. The influence of the flame treatment on the anti-corrosion performance of the coatings was comprehensively studied. Diverse corrosion protective efficiency could be achieved by simply adjusting the flame treating time. It was found that the optimized flame time was 10 min and the resulted sample showed a minimum corrosive current density of 13.27 μA/cm2, which was reduced by ~20 times as compared to that of bare Ni-plated carbon steel, leading into a remarkable protective efficiency of 97.26% in 0.1 M HCl. In contrast, such a great promotion could not be realized at all for the bare carbon steel subjected to the same flame treatment, which was due to the contrasting catalytic activity of Ni and carbon steel for the flame deposition of carbon, as analysis indicated that only Fe3O4 rather than carbon film was produced in the case of bare carbon steels. Moreover, the highest bonding level (5B) was achieved for the carbon film to the substrate, which could be related to the unique carbon/Ni staggered interface in situ formed during the flame deposition process. The facile deposition of the anti-corrosive carbon topcoat and its strong bonding to the metal substrate will find its promising practical application in various industries.