Kinetics of the High Temperature Oxidation of the Inconel 686 Coatings in the Waste Incineration Ash

Abstract

In this paper, detailed characterization of the oxide scale, grown on the Inconel 686 coating after high-temperature oxidation at 650°C in ashes from waste incineration power plant was performed. Phase composition, morphology, microstructure and chemical composition of the oxide scale were investigated using XRD and SEM analysis. Mechanisms of formation and growth of oxide scales were examined, resulting in the insights into oxidation kinetics. Results revealed presence of NiO in the outermost layer of the oxide scale. At the bottom of oxide scale, CrNi2O4 spinel layers were formed due to the increasing concentration of Cr. In the middle area of oxide scale, due to higher concentration of Cr and lower amount of Ni, the Cr2NiO4 spinel is formed. The innermost layer was composed of Cr2O3.

Keywords

• inconel 686 alloy
• sem
• xrd
• high-temperature corrosion