The mitigation of CO₂ emissions is one of the major areas of research in iron ore-based steelmaking. In this study, four simulated current and potential future reheating scenarios with different fuel and oxidizer gases were studied regarding the amount of oxide formation and the adhesion of the steel–oxide interface: (1) methane–air; (2) coke oven gas–air; (3) hydrogen–air; (4) and an oxyfuel scenario with 50:50 methane/hydrogen as fuel gases. Isothermal oxidation tests were conducted at temperatures of 1150, 1230 and 1300 °C. Four low-carbon steel grades were tested in the previously mentioned gas atmospheres. The structure and composition of the formed oxide scales was analyzed with FESEM-EDS microscopy. The amount of oxide formation correlated with the water vapor content of the gas atmosphere for all four steel grades; however, notable differences were found between individual steel grades regarding the degree of oxidation increase. No clear evidence was found of the gas atmospheres affecting the adhesion of oxide scales to the steel substrate. The adhesion of the interface was mainly determined by the content of silicon in the steel grade and the test temperature.

The worldwide commitment to large-scale CO ₂ reductions is forcing steel producers to find improvements to reheating processes for steel slabs. In this study, three practices with potential to lower the carbon footprint of reheating process for steel slabs were studied: use of hydrogen as fuel gas, replacement of air with pure oxygen (oxy–fuel), and electrical heating. The oxidation behavior of steel in these conditions was simulated using a thermogravimetric analyzer (TGA) at high temperatures (up to 1250 °C). Four carbon steel grades, seven different gas atmospheres, and two dynamic heating profiles were included in the test matrix. When compared to the standard reheating practice using natural gas–air, scale formation increased moderately in hydrogen–air and significantly in oxy–fuel gas atmospheres but decreased in the case of simulated electrical heating. With simulated oxy-fuel combustion, no meaningful difference was found between H ₂ and a 50:50 CH ₄ –H ₂ mix in terms of oxidation kinetics. A reduction of the free oxygen content from 2.5 to 1.0 pct was more effective at reducing overall oxidation in the case of CH ₄ –air compared to H ₂ –oxy–fuel.