Oxidation of simulated recycled steels with 0.23 and 1.03 wt.% Si in Ar–20%H2O at 900 °C

• A framework for dynamic analysis of oxide stability was proposed.
• For the global reaction mechanism, water vapour was a main reactant for oxidation.
• Oxidation of the simulated recycled steels containing Si was linear-parabolic.
• Higher Si content in the steel prolonged the period of linear oxidation.
• Increasing Si from 0.23 to 1.03 wt.% increased the oxidation rate of the steel.

Simulated recycled steels containing 0.002, 0.23 and 1.03 wt.% Si were oxidised in Ar–20%H2O at 900 °C. The oxidation kinetics of the steels was linear-parabolic. Higher Si content in the steel resulted in prolonging the period of linear oxidation and increasing Si content from 0.23 to 1.03 wt.% enhanced the parabolic oxidation rate constant. The integrated framework using thermodynamic analysis in static and dynamic modes together with the stoichiometric one was proposed for analysing the global reaction mechanisms. The role of hydroxyl ion on the oxidation behaviour of the steels was discussed.