Relationship between Morphology of Nonmetallic Inclusion in Solidified Steel Evaluated by Fractal Dimension Analysis and Oxygen Concentration of Its Molten State

Relation between morphology of nonmetallic inclusion in solidified steel and oxygen content in its molten state is examined. The oxygen content in the molten steel is observed by an oxygen sensor with solid electrolyte. It is revealed that morphology of the nonmetallic inclusion can be expressed by fractal dimension and fractal length. The larger oxygen content gives the larger fractal length. The fractal dimension of each nonmetallic inclusion is about 1.2. The fractal dimension is not affected by oxygen content in molten steel.