Effect of Al Content on the Evolution of Non‐Metallic Inclusions in Si–Mn Deoxidized Steel

Abstract

Industrial trials and thermodynamic calculations are performed to investigate the effect of Al content on the evolution of non‐metallic inclusions in Si–Mn deoxidized spring steel by using scanning electron microscope (SEM) equipped with energy dispersive spectrometer (EDS) and FactSage thermodynamic software. Sulfide type inclusions and CaO–Al2O3–SiO2–MgO type complex inclusions are two major non‐metallic inclusions. The effect of Al content on the evolution of CaO–Al2O3–SiO2–MgO system inclusions is discussed. The stability diagram of Fe–Mn–Si–Al–Mg–O system inclusions is calculated in liquid steel at 1873 K. In practice, to achieve the liquid inclusions in molten steel, both the amount of magnesium and aluminum should be considered simultaneously.