Study on the Source of Oxide Inclusions Originated from Casting-Pit Refractories by Zircon Tracer

Abstract

In order to investigate the source of oxide inclusions orignated from refractories of casting-pit in top-teeming ingots, Al₂O₃-SiO₂ refractory zircon (Containing 10% and 40% as ZrO₅) were used as the bottom lining of trough and ladle, trough nozzle, and the lining of mould top.
The behaviors of oxide inclusions originated from refractories of casting-pit were studied by determining ZrO₂ content in oxide inclusions extracted from steel specimens.
The following results are obtained.
(1) The entrapped quantity of the trough bottom brick into oxide inclusions was about 10% and the entrapped quantity into oxide inclusions was in the order of; trough bottom brick>ladle bottom brick trough mortar>trough nozzle brick>trough ramming materials>castable refractories for mould top.
(2) Some comparisons were made between zircon tracer method and R.I. method in the investigation of the formation of oxide inclusions originated from refractories of casting-pit.