Inclusion characteristics in bearing steel before and during ingot casting

Size, distribution, and compositions of inclusions were studied during seco ndary refining and casting in application to high-carbon chromium bearing s teel production. Samples were collected in the ladle, tapping stream and mo ld. Total oxygen content, number of inclusions and composition of inclusion s were then determined using melt extraction, optical microscopy and scanni ng electron microscopy, respectively. The results show that the inclusion c haracteristics do not change significantly during the final treatment in th e ladle. A future change in stirring conditions may therefore be necessary. The analyses of the samples taken in the tapping stream and in the mold sh owed an increase in the oxide inclusion content This increase is most likel y due to reoxidation during sampling.