Roles of permeated hydrogen in the oxidation process of Ni-based alloy in high temperature water environment

Abstract

The present research proposes the synergistic roles of H involved in the oxidation process of a Ni-based alloy in high temperature water environment, using an in-situ H-permeating method. The roles of H were differentiated according to the modification on the microstructure during oxidation in high-temperature water, as H is situated at multiple locations during permeating the material. The nature of the oxide was found to be modified significantly, however, it exhibited possibly opposing impacts on the reliability of the materials. The integrity of surface oxide film and matrix/oxide interface were degraded, yet grain boundary was protected by permeated H.