Slag formation during high temperature interactions between refractories containing SiO2 and iron melts with oxygen
2004 (English)In: Ironmaking & steelmaking, ISSN 0301-9233, Vol. 31, no 6, 509-513 p.Article in journal (Refereed) Published
Refractory-metal interactions and associated reactions are important during casting as they can lead to the formation of inclusions. High temperature interactions between aluminosilicate refractories and molten steel were studied in the present investigation using the sessile drop method. Changes in the contact angles between molten iron with well defined oxygen levels and substrates of silica, mullite (3Al(2)O(3).2SiO(2)) as well as commercial refractories, were measured in the dynamic mode. In all cases, the reaction led to slag formation. The experiments were performed under isothermal conditions at 1823 and 1873 K. A known and constant oxygen partial pressure was imposed above the iron drop, through appropriate CO-CO2-Ar mixtures. For all substrates, the contact angles started decreasing due to lowering of the surface tension of iron, as oxygen was imposed onto the system. When a critical level of oxygen was reached, slag started forming at the drop/substrate interface and at this stage, the contact angle dropped suddenly. Subsequent behaviour of silica and mullite was observed to be different, with SiO2 showing a non-wetting behaviour. In the case of SiO2 substrate, there were also deep erosions along the periphery of the drops and there was slag accumulation at the sides of the metal drop, probably due to Marangoni flow and/or SiO(g) formation. SEM and EDS analysis of the substrates revealed that the formed slag was fayalite. The thermodynamic criteria for slag formation and possible mechanisms of the reaction are discussed in the light of the experiments.
Place, publisher, year, edition, pages
2004. Vol. 31, no 6, 509-513 p.
silica, mullite, fayalite, corundum, slag formation, sessile drop, sessile-drop technique, wetting characteristics, liquid-iron
Metallurgy and Metallic Materials
IdentifiersURN: urn:nbn:se:kth:diva-23972DOI: 10.1179/030192304225019379ISI: 000225997600013ScopusID: 2-s2.0-10944220896OAI: oai:DiVA.org:kth-23972DiVA: diva2:342671
QC 20100525 QC 201110252010-08-102010-08-102011-11-01Bibliographically approved