The direct relationship between the total oxygen content of the steel
or the slag composition and the rate of surface defects on the final
products has been clearly established by many previous studies.
The paper describes the appropriate process parameters to prevent
the re-oxidation of the molten steel and clogging of the submerged
entry nozzles, two essential factors to meet the product cleanness
requirements: quantification of re-oxidation, control of re-oxidation
by slags, air or refractories, control of Ar injection, mechanisms and
ways to reduce CC nozzle clogging.