Investigation of oxidation resistance of carbon based first-wall liner materials of fusion reactors

Oxidative erosion of graphite in air between 600 and 1000K

“…Such a tendency has also been previously observed for NS31 and N112 [26,28,29] and results from the widening of the pore system, i.e., from increasing the effective surface area. The rates before the increase are plotted in Fig.…”

“…At higher temperatures (>1200 K), the mass transfer to and away from the surface is the slowest step and, as a result, the erosion is only slightly temperature dependent [21,28,31,32]. For lower temperatures (<900 K) the chemical reaction between oxygen and carbon is the rate limiting process [27,28,33,34]. The transition temperatures between the different ranges depent on various parameters such as specimen porosity, microscopic structure, specimen shape and size, partial and total pressure, and the presence of water vapour [26,28].…”

“…For lower temperatures (<900 K) the chemical reaction between oxygen and carbon is the rate limiting process [27,28,33,34]. The transition temperatures between the different ranges depent on various parameters such as specimen porosity, microscopic structure, specimen shape and size, partial and total pressure, and the presence of water vapour [26,28]. The kinetic energy of molecular oxygen also affects the oxidation behaviour [14,31,32].…”

“…Investigations on such accident analyses [20,[26][27][28][29][30] were carried out above 900 K, where the in-pore diffusion of the gases is the rate limiting process. At higher temperatures (>1200 K), the mass transfer to and away from the surface is the slowest step and, as a result, the erosion is only slightly temperature dependent [21,28,31,32]. For lower temperatures (<900 K) the chemical reaction between oxygen and carbon is the rate limiting process [27,28,33,34].…”

Tritium release behavior from the graphite tiles used at the dome unit of the W-shaped divertor region in JT-60U

“…Studies on the reaction between carbon and oxygen have been carried out and the erosion rate of graphite at wide temperature region is summarized as the erosion yield, C/O 2 [29]. Carbon and water vapor reactions at high temperature have been also studied from several viewpoints such as a safety of fusion rector with regard to loss of coolant inside the vacuum vessel [30][31][32], erosion of carbon based material used as gas turbine blades or scramjet combustors [33,34] and gasification of coal, coke or carbon with water vapor [35]. It is considered from those earlier studies that graphite would be eroded by following reactions with oxygen,…”