High temperature oxidation of Cr-Mo-V tool steel in carbon dioxide

This study aims to examine the oxidation resistance and kinetics of Cr, Mo, and V containing tool steel (Calmax) when exposed in CO2 high temperature environment by thermogravimetric measurements, X-ray diffraction analysis, and microscopic observation. The tool steel samples begin to oxidize at 480 A degrees C while over 600 A degrees C, the oxidation rate increases significantly. Finally, at 900 A degrees C, the oxidation rate is significantly high. The activation energy of the oxidation was calculated as 160.1 kJ mol(-1). Microscopically, the thickness of the scale was found to increase with the exposure temperature, and the as formed scales consisted of two distinguishable oxide layers.