Observation of Inclusions in Manganese--Silicon Killed Steels at Steel--Gas and Steel--Slag Interfaces

摘要

The behaviour of inclusions on the surface of molten steel and at molten steel-slag interfaces was observed in-situ using a Confocal Scanning Laser Microscope (CSLM). Solid irregular and liquid spherical inclusions were observed on the molten steel surfaces. They were found to cluster and agglomerate, driven by capillary depression forces and they were identified as Al_2O_3-MnO-SiO_2, Al_2O_3-MnO and Al_2O_3 particles in quenched samples. At steel-slag interfaces, inclusion clustering was also observed. Here a weak repulsive force was found to oppose fluid flow driven clustering. The inclusions were found to react with the slag and to undergo changes in shape, size and chemistry. Examination of the interface after the experiments revealed that the inclusions were enriched in CaO, SiO_2 and Al_2O_3 from the slag.