Characterization of 2D and 3D morphology of Al2O3 inclusion in hot rolled ultra-low carbon steel sheets

In this work, the two-dimensional (2D) morphology of Al2O3 inclusions with oval and polygon was observed. The non-aqueous electrolysis extraction method was employed for extraction and characterization of the real three-dimensional (3D) morphology and size of inclusions in hot rolled ultra-low carbon steel sheets. The integrated morphology and size of Al2O3 inclusion were obtained through scanning electron microscopy along with an energy-dispersive spectrometer. Compared with 3D morphology and size of Al2O3 inclusions, the 2D morphology and size are hardly accurate to describe the real morphology and size. Additionally, the mechanical property of Al2O3 inclusion and steel matrices were tested by nano-indentation. The real morphology, size and mechanical properties of Al2O3 inclusions will help to establish, develop and validate the damage model or criteria, as well as to improve the quality of rolled productions.