OXIDATION BEHAVIOR AND MICRO STRUCTURE ANALYSIS OF NUCLEAR GRAPHITE IG-110 AT 520℃ UNDER AIR ENVIRONMENT

Graphite IG-110 is a nuclear graphite structural and moderator material that has been used for high temperature gas cooled reactors (HTGR). Under normal operating conditions or accidental entry of air or water (air ingress or water ingress), a nuclear graphite. Therefore, the aim of this study is to investigate the oxidation resistant and microstructure change behavior of graphite IG-110 at high temperature under air environment. The sample of IG-110 was tested using Magnetic Suspension Balance (MSB) to analyze the weight change by in-situ for 420 minutes at a temperature of 520oC. Morphological and microstructure analysis was carried out by optical microscope, SEM-EDS (Scanning Electron Microscope –Energy Dispersive X-ray Sprectroscope) and XRD (X-Ray Diffractometer). The results showed that Graphite IG-110 has a change in surface structure caused by the reaction of the material with oxygen in air at high temperatures. Furthermore, the crystal size of the material structure was slightly change. However, in general, the corrosion rate of graphite IG-110 at a temperature of 520℃ under the air environment is relatively low. So that if graphite IG-110 is exposed to air at a temperature of 520℃ for several hundred minutes in a nuclear reactor estimated does not suffer serious damag