The effect of grain boundary engineering on the oxidation behavior of INCOLOY alloy 800H in supercritical water

摘要

Grain boundary engineering (GBE) was applied to INCOLOY alloy 800H by means of thermomechanical processing. The oxidation behavior of GBE-treated alloy 800H exposed in supercritical water (SCW) with 25 ppb dissolved oxygen at 500 degrees C and 25 MPa was significantly improved as compared to 800H in the annealed condition. Gravimetry, optical microscopy, scanning electron micro scopy/energy dispersive X-ray spectroscopy (SEM/EDS), X-ray diffraction (XRD), and electron backscatter diffraction (EBSD) were employed in this study to analyze the oxidation behavior of control (annealed) and GBE-treated samples. GBE improves the protective oxidation behavior by enhancing spallation resistance and reducing oxidation rate. Spallation resistance correlates with a reduction in texture of the oxide layers. (c) 2005 Elsevier B.V. All rights reserved.