An examination of the clogged nozzles used for stainless steels containing rare earth metal (REM) was performed. The accretion mainly consisted of solidified metal in which Ce and La oxides, which were considered to promote nucleation of delta ferrite, were observed at the nozzle/metal interface. To prevent nozzle clogging, a study has been further conducted to determine the effects of Ce and Al for deoxidation on inclusion composition in 25Cr-6Ni stainless steel. The rate of the decrease in oxygen content is lower when both Ce and Al were added than when only Al was added. The compositions of the inclusions after deoxidation were analyzed as an Al_2O_3-Ce_2O_3 system. The quantitative analysis revealed that the Ce_2O_3 content increased with increasing Ce content in the molten steel. The composition of deoxidation products took only compounds of Al_2O_3, CeAl_(11)O_(18), CeAlO_3 and Ce_2O_3. As a result, an appropriate timing of addition and ratio of Al and Ce was determined to prevent nozzle clogging, avoiding the formation of Ce_2O_3 inclusions.
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