Characteristics, Origin, and Heritability of Large-Size Inclusions in a Low Alloy High Strength Steel

The rare oxide, La 2 O 3 , was added to the refined slag as a tracer to evaluate the origin of large-size inclusions in the steel. The composition of CaO-Al 2 O 3 was similar to that of the VD refining slag. Three different forms of inclusions came from the slag entrainment and the amount were large. The proportion of large-size inclusions caused by calcium treatment was stable and small. Besides, the formation mechanism of large-size inclusions was also discussed.