Research on Corrosion Behavior of Al₂O₃ and Al₂O₃-MnS Inclusions in Non-oriented Silicon Steel

The annealed samples of non-oriented silicon steel were used for in-situ corrosion experiments, and the surface corrosion morphology of the samples was characterized by OM, SEM, EDS and Raman spectroscopy. The results show that the corrosion of non-oriented silicon steel originates from the localized corrosion of inclusions, including metal oxide inclusions Al₂O₃ and metal oxysulfide inclusions Al₂O₃-MnS. During the initial corrosion of non-oriented silicon steel, the corrosion products in the circular rust spots are mainly γ-FeOOH and α-Fe₂O₃, and the content of γ-FeOOH is higher than that of α-Fe₂O₃.As the color of the corrosion products deepens, the content of α-Fe₂O₃ gradually increases.