Corrosion Mechanisms of SEN Slagband Materials
摘要
Wear of a zirconia graphite slagband material by mold slag during casting of a TRIP steel grade was investigated on worn specimens with respect to corrosion and erosion.Corrosion dissolution of both the stabilizer oxide and the zirconia is decisive.Oxidation is dominating graphite wear whereas a possible dissolution in the liquid steel was not observed to play an important role here.The ratio of oxide corrosion to graphite oxidation decreases with decreasing vertical distance of the hot face to the steel bath.Unfortunately and contrary to other applications of carbon bonded refractories in steel industry graphite exhibits to be wetted by mold slag in the special case investigated here,it still acts as a refractive component, but only partly as an infiltration inhibitor.Infiltration is followed by zirconia corrosion thus reducing erosion resistance,but nevertheless also gas phase transport of slag components may cause exsolution of the stabilizer oxide in un-infiltrated regions.