Inclusions in the Mechanical Capped Steel

Abstract

A study on the macroscopic inclusion in the rim and core zones of large mechanical capped steel ingots (23t-34t weight) has been carried out. The slime method was utilized for extracting inclusions.
(1) In the lenticuler blow holes in the rim zone there are many large macroscopic inclusions. A part of these inclusions is a glassy oxide which is made from (Fe. Mn) -Si-Al-O, and another part is a large lumpy inclusion which is made from Al₂O₃.
(2) The former inclusions (glassy oxides) which from a tortoise shell-shape stick on the inner side of lenticuler blow holes, and the latter (Al₂O₃) which forms a lumpy type pops out into lenticular blow holes.
(3) In the blow holes in the core zone there are large lumpy almina inclusions, and there are more in the upper part of the core zone than in the middle and the bottom part.
(4) These large lumpy inclusions are caught by the blow holes in the core zone and carried by them into the inner part of the zone.
(5) However, in the blow holes at the core zone no inclusion of the tortoise shell-shape is found.