Oxide Inclusions at Different Steps of S

The formation of oxide inclusions in one of the carbon steel productions of Mobarakeh Steel Complex of Isfahan has been evaluated. Several samples from different steps of steel production were taken, including from the arc furnace, ladle furnace, tundish, and continuous casting mold. Additionally, samples of slab and hot rolling products were prepared for analysis. The samples were investigated using optical and scanning electron microscopes equipped with an EDS system. The results indicated that the number, composition, and types of inclusions were directly influenced by the production variables. Specifically, it was found that when the amount of dissolved oxygen exceeded 0.0025%, dissolved aluminum could reduce silicon oxide while concurrently reacting with the dissolved oxygen; conversely, aluminum could only reduce magnesium oxide when oxygen content was below 0.0005%. Based on these findings, a mechanism for forming complex inclusions was proposed. Furthermore, it was discovered that adding aluminum to the melt later in the process led to a cleaner melt with fewer inclusions, particularly effective for complex inclusions.