Abstract
Virtually all grades of steels exhibit reoxidation during the steelmaking, refining and casting processes. In this paper, reoxidation on the surface of low-carbon, Al-killed steel melts before Ca-treatment was investigated by direct observation of oxide evolution through a confocal scanning laser microscope equipped with a gold image furnace. The formation, growth and clustering of oxides were quantified on molten aluminum-killed steels at different oxygen partial pressures, gas flowrates and temperatures. A scanning electronic microscope (SEM) equipped with an energy dispersive spectroscopy (EDS) system was used to characterize the inclusions formed under different experimental conditions. The time period necessary for observable reoxidation to occur was a function of temperature and also the gas flowrate. A gas-phase mass-transfer of oxygen through a gas boundary layer to the melt surface led to supersaturation and subsequent inclusion formation. The oxide growth decreased at higher experimental temperatures. When the individual crystals were large enough, the capillary depression led to attractive forces over 10-17 N and consequent particle agglomeration on the surface of steel.
Original language | English (US) |
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Pages (from-to) | 87-96 |
Number of pages | 10 |
Journal | Iron and Steel Technology |
Volume | 1 |
Issue number | 2 |
State | Published - Feb 2004 |
Externally published | Yes |
ASJC Scopus subject areas
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry