Graphene prepared by gamma irradiation for corrosion protection of stainless steel 316 in chloride containing electrolytes

Abstract

In this work we demonstrated the effective use of gamma irradiation for useful chemical conversion. Thus, graphene oxide was reduced to graphene upon exposure to gamma irradiation. The resulting gamma irradiated graphene (GIG) and graphene-covered steel were characterized using UV-Vis, XRD spectroscopies and FE-SEM. Corrosion protection of austenitic stainless steel AISI 316 by GIG and gamma irradiated graphene/chitosan (GIG/CS) composite films in 3.5% NaCl solution was investigated using potentiodynamic polarization and electrochemical impedance spectroscopy. The protection efficiencies for GIG and GIG/CS were 82.2% and 89%, respectively. GIG/CS films over steel showed higher corrosion activation energies compared to GIG. EIS proved the stability of GIG and GIG/CS coatings after different immersion times in 3.5% NaCl solution. Coated surfaces were free from pits on the scale of magnification as demonstrated from SEM images. The pitting corrosion behavior of uncoated and GIG-coated surfaces was also studied.