Comparison of the Emissivity Changes due to Oxidation of Nuclear Graphites IG-11, IG-110 and PCEA

摘要

The emissivity of the nuclear graphites was measured in comparison with the oxidation degrees. IG-11, IG-110 and PCEA nuclear graphites have been used as samples. Oxidation reaction of the graphite was carried out in air (5 L/min) using tube furnace (600 °C; chemical reaction regime). Oxidized (about 5%, 10% weight loss) and non-oxidized samples have been chosen for the emissivity measurement. There were five different temperatures of 100°C, 200°C, 300°C, 400°C and 500 °C for measuring emissivity. The overall emissivity of oxidized samples is much higher than non-oxidized samples. Differences in the emissivity behaviors of three samples were discussed in the scope of the differences in the microstructure and surface roughness.