Analysis on Oxidation Behavior of HR3C Steel at 700°C in Water Vapor

Abstract

HR3C is an advanced heat-resistant alloy, and its high-temperature oxidation resistance directly determines the service performance of the material. Therefore, exploring the high-temperature oxidation behavior of HR3C is of great significance for the theoretical research and practical application of the material. The oxidation kinetic curve, oxide film morphology, oxide film composition, and oxide film phase composition of HR3C samples in the supply state after being oxidized in water vapor at 700°C for 50h, 150h, 250h, 350h, 450h, 550h and 600h were analyzed by SEM (Scanning Electron Microscopy), EDS (Energy Dispersive Spectroscopy) and XRD (X-ray diffraction). The results show that the oxidation kinetic curve of the material conforms to the parabolic law, the oxide film first forms a lamellar oxide, and the lamellar oxide film grows alternately to form a loose and porous oxide film surface, the oxide is composed of three oxides: Fe₃O₄, FeCr₂O₄ and Fe₂O₃. The FeCr₂O₄ is a spinel compound, which can form a dense oxide film, and the diffusion coefficient of metal ions in it is small, which hinders the diffusion and mass transfer of ions, thereby improving the high temperature oxidation resistance of stainless steel. The element Cr is mainly enriched in the inner oxide layer, and the element Fe is relatively high in the outer oxide layer.