Reheating of steel slabs before hot rolling is one of the major sources of CO 2 emissions from the steelmaking industry. The use of hydrogen as a fuel gas, the replacement of air as the oxidizer gas with pure oxygen (oxy‐fuel), and electrical heating have been identified as potential process improvements that could significantly reduce the carbon footprint of the reheating step. This study focuses on changes in oxide scale morphology under different simulated reheating conditions. The oxidation behavior of four carbon steels with varying elemental compositions was studied using a thermogravimetric analyzer at temperatures up to 1250°C. Field‐emission scanning electron microscopy was used to estimate adhesion at the steel–scale interface and to evaluate the pore structure after oxidation. Iron oxides were identified, and their relative proportions were estimated using X‐ray diffraction. Energy‐dispersive spectroscopy was employed to map the enrichment behavior of secondary elements (Si, Ni, and Cr). Changes in various properties of the oxide scale were documented under both current and potential future reheating conditions. This study advances our knowledge on reheating steel using more environmentally and energy‐efficient methods.
Haapakangas et al. (Thu,) studied this question.