Development and validation of a model for the chemical kinetics of graphite oxidation

Characterizing thermal-oxidation behaviors of nuclear graphite by combining O2 supply and micro surface area of graphite

“…For oxidation behaviors with high gas flow rate, the microstructure of graphite, such as surface area, was indicated to be a constant object at a certain range of Mass Loss (ML), which was independent from temperature and O 2 supply 16 , 17 . Simultaneously, the standard of ASTM D7542 recommended the method to calculate the activation energy of graphite oxidation using average oxidation rates from 5% to 10% ML of specimen.…”

Pore structure development in oxidized IG-110 nuclear graphite

“…Porosity is inherent in nuclear graphite due to the gas evolution and thermal contraction during fabrication. Pores serve as the transport channels of oxygen into the bulk of graphite and provide the active sites for reaction [7], thus the pore system plays an important role in the oxidation behavior. On the other hand, the increase of porosity of the oxidized graphite has a remarkable impact on the material's mechanical properties [8][9].…”

CO2corrosion of IG-110 nuclear graphite studied by gas chromatography

“…P CO 2 is the partial pressure of the CO 2 gas at the reacting surface and the superscript n reflects the reaction order. A is the active surface area which is a fraction of the total surface area [12]. The active surface refers to the carbon atoms at lattice discontinuities including the prismatic and pyramidal faces of the graphite crystallites and those at defective centers in the basal planes.…”

“…Since E a and the reactive surface area (A) are determined by the carbon dioxide-carbon reaction and the nature of the IG-110 graphite, respectively, they are both independent of temperature [12]. Thus the reason for the observed deviation is thought to lie in the change of P CO 2 at the reacting surface.…”

“…Hu et al In the literature, the gasification of carbon is usually divided into two regimes: the kinetic-controlled regime at low temperatures and the diffusion-controlled regime at high temperatures [12,13]. In the kinetic-controlled regime, the corrosion rate is controlled by the reaction kinetics; while in the diffusion-controlled regime, the corrosion rate is limited by the diffusion of the reacting gas.…”