Comparison Study on Air Oxidation Behavior of Advanced Super-Alloys In Elevated Temperatures

Abstract

Nickel based Superalloys play an important role in ensuring the integrity, durability and long-term performance of nuclear reactors. They are used in the heat transfer and cooling systems as well as in the reactor vessel internals. The air oxidation resistance of four different nickel based alloys including Alloy X750, Alloy 230, Alloy 625SQ, and HASTELLOY N at 600, 800, and 1000 °C has been evaluated. Morphology of surface and cross-section of oxide scales were studied using Scanning Electron Microscope equipped with Energy Dispersive X-ray Spectroscopy. We also used X-ray Diffraction to identify oxide phases formed on surface of samples. Furthermore, Microtexture of as received alloys and existing oxide phases and also microtexture of starting samples were analyzed.