Benefits of gas phase analysis facility using isotopically labelled gases for the understanding of gas–solid reactions: Reactivity of iron and mild steel in O2, CO2 and CO2/O2 environments

Corrosion of iron and mild steel in gas environments at 550 °C was studied by Gas Phase Analysis (GPA) using 13C16,16O2 18,18O2. This technique is shown to be very powerful identifying gas–metal gas-gas interactions. Mild reacts with O2 oxidize decarburise, CO2 decarburise but not oxidize, CO2/O2 carburise. Using simple kinetic modeling, it demonstrated that the oxidation rate initially controlled almost exclusively dissociation adsorbed O2. In this regime, acts mainly limiting access surface.