Effects of Added Cr and Ni on the Resistance of alpha-Iron Surface to Cl-2 Gas Corrosion

Abstract

As energy generation by recycling biomass has become increasingly attractive, research on biomass recycling has focused on improving operational efficiency. To develop a new material composition for the inner wall of a biomass boiler, we investigated the effect of Cr and Ni addition on the resistance of the alpha-iron (100) surface to Cl-2 gas corrosion using first principles theoretical calculations. We constructed model systems by partly substituting the outermost Fe atoms on the alpha-iron (100) surface with Cr and Ni atoms, and then calculated the adsorption energy of Cl and the escape energy of Fe on the surface. The adsorption energy results indicated that Ni added to the surface hindered the adsorption of Cl onto the surface, while Cr had little effect. The addition of both Cr and Ni greatly hindered the escape of Fe atoms from the surface. The mechanism governing the hindrance of the Cl adsorption differed between the Cr and Ni. The Cr hindered the escape of Fe atoms by increasing cohesive energy, while the Ni stabilized the alpha-iron (100) surface and in turn hindered the adsorption of Cl-2 gas.