Incorporation graphene into sprayed epoxy–polyamide coating on carbon steel: corrosion resistance properties

ABSTRACT

In this study, the graphene incorporated into epoxy–polyamide coatings were successfully obtained on carbon steel substrates by spraying process. The corrosion resistance properties of the coatings were investigated, including salt spray corrosion, sea water corrosion and electrochemical corrosion resistance. The results show that the addition of graphene could improve the corrosion resistance properties of the epoxy–polyamide coatings. The coatings in the presence of graphene had better salt spray corrosion than that in the absence of graphene. The surface of the epoxy–polyamide coating exhibited lots of pitting corrosion. The coatings with the addition of graphene showed better sea water corrosion than the coating without graphene. After drying, the epoxy–polyamide coating in the absence of graphene was broken and failed. The coating with 1 wt-% graphene exhibited the best anticorrosion capability as evidenced by the highest corrosion potential and the lowest corrosion current density. The graphene incorporated into epoxy–polyamide coatings were shown to effectively protect carbon steel against corrosion because the graphene nanosheets could be acted as the good chloride ions, oxygen and water molecules barrier.

KEYWORDS:

• Graphene
• epoxy–polyamide
• coating
• corrosion
• electrochemical

Acknowledgements

The authors want to thank Mr Yuxin Huang to support a high-pressure gun, and Dr Lei Zhang from the Changshu Institute of Technology to his helpful contribution in characterisation of the graphene.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Wangping Wu http://orcid.org/0000-0003-3956-9512

Additional information

Funding

This research was supported by the funding of the Project of Undergraduate Practical Innovation in Jiangsu Province [grant no. 2017-03-C-13] and the Funding of Jiangsu Key Laboratory of Green Process Equipment [grant number: GPE201702].