Characterization of recycled Q235 steel chips from rolling billet scales

In the last decades, the demand for steel has increased exponentially generating tons of waste impacting the environment. The most common waste in steelmaking process are slags which are produced during the rolling process of steel billets. This situation has encouraged the scientific community in finding environmentally possible ways to take advantage of this slags. In this work, we present the structural and magnetic properties of solid state recycled Q235 steel chips obtained by powder metallurgy and extrusion process from oxide scales of billets. The characterization of the recycled Q235 chips was performed by X-ray diffraction, Mössbauer spectroscopy and magnetic measurements. The X-ray diffraction reveals α-Fe as the predominant crystallographic phase and non-stoichiometric wüstite in minor amount. The Mössbauer spectrum revealed a sextet associated to α-Fe phase with a hyperfine magnetic field B_hf ~ 33 T and two doublets associated with Fe²⁺ and Fe³⁺ from the non-stoichiometric wüstite. Magnetic measurements show a ferromagnetic behavior because the presence of α-Fe which is the predominant phase and hysteresis is also observed under low applied fields.