Papers by Keyword: Submerged Entry Nozzle

Abstract: Abstract. One of the everlasting problems existing in alloy steel plant is clogging of Submerged Entry Nozzle(SEN) due to accumulation of De-oxidized/Re-oxidized products while casting Medium Carbon Re-Sulfur Steel grades(forging grades).After complete De-sulphurization and De-oxidation, liquid steel have been subjected to Ca-treatment which promote deep De-oxidation and deep De-sulphurization in addition to inclusion morphology control. Finally liquid steel have been injected with sulfur cored wire for chemistry requirement of 0.02-0.035%. All these conditions encourage thermodynamically favorable conditions for formation of various combination of oxide and sulphide inclusions which are highly detrimental to castability in continuous casting of integrated steel mill. This becomes one of the major process interruptions which directly terminate production capacity day by day and also affects the quality of cast product. As well said before “Best Slag Maker Is Best Steel Maker”, we mainly focused on secondary steel making slag at different stages, and found the relation of castability with respect to slag behavior. We arrived at optimal slag nature for better castability in continuous casting of steel.

Abstract: Submerged Entry Nozzle (SEN) are usually made from a combination of carbon bonded alumina, zirconia and magnesia with graphite, which have been found to give the best response to the extreme demands of thermal shock, corrosion and erosion resistance. SEN brittle fracturing and clogging is a serious productivity and quality problem in continuous casting. The SEN critical area of failure is the steel flange where the SEN neck is fixed. Thermal shock or mechanical stress may cause cracking, which can result in premature failure. Preheating on optimal temperature before SEN installation is the standard procedure. Thermal stress effect on fracture behavior was done by analyze of material fractography, morphology, macrostructure and microstructure.