Effects of surface temperature, flow velocity and ambient pressure on the oxidation of graphite at 1400–2000 °C in O2

• The oxidation behavior of graphite at 1400–2000 °C in O2 was investigated.
• The effects of flow velocity gradient and ambient pressure were investigated.
• The weight loss kinetics were analyzed by the chemical reacting boundary layer theory.
• The gas phase CO–O2 reaction exhibits a joint reduction effect on the weight loss rate.

The effects of surface temperature (1400–2000 °C), flow velocity gradient (130–600 s−1) and ambient pressure (5–101 kPa) on the oxidation behavior of graphite were studied in O2. The weight loss rate between 1400 and 1800 °C is independent of the surface temperature but slightly decreases at 2000 °C. Besides, it displays quasi-parabolic increases with increasing the flow velocity gradient and the ambient pressure but levels off above the ambient pressure of 20 kPa. According to the theoretical analysis, the enhancement of the gas-phase CO–O2 reaction has a joint reduction effect on the weight loss rate.