Thermo-calc and SEM analysis of the dolomite lining during steel refining
2008 (English)In: Proceedings for the Third Nordic Symposium for Young Scientists in Metallurgy, 2008, 46-50 p.Conference paper (Refereed)
Dolomite refractories are widely used in the slag line of the steel refining vessels working in basic conditions. A Postmortem analysis (SEM investigation) has been carried-out on the dolomite refractory material after service in industrial conditions to identify its corrosion behaviour during steel refining. Results from the SEM investigation indicate that the high corrosion rate of this refractory could have been caused by the presence of a high content of iron oxide and silica in the slag, which possibly reacted with the refractory components at refining temperatures. High silicate slag lead to low temperature melting phases and therefore decreased corrosion resistance. The high content of iron elements and their distribution in the penetrated microstructure may indicate the oxidation of carbon by iron oxide in the slag with more slag penetration as a result. These results have then been combined with the thermodynamic calculation results by the Thermo-Calc program so that the behaviour of this refractory at refining conditions could be examined. Thermo-Calc results verified more graphite reduction with increasing iron oxide content in the slag. Other instability problems such as the MgO-C reaction and more increased low temperature melting phases such as tri-calcium silicates also weaken the refractory. This work is intended to increase the understanding of the corrosion behaviour of the steel refining refractories, which is a key factor for prolonging ladle life.
Place, publisher, year, edition, pages
2008. 46-50 p.
corrosion, dolomite, refractories, slag, slag penetration, reactions, corrosion behaviour
IdentifiersURN: urn:nbn:se:kth:diva-25165OAI: oai:DiVA.org:kth-25165DiVA: diva2:356253
TKK, Espoo, Finland
QC 201010122010-10-122010-10-122010-10-13Bibliographically approved