End product rejection rate and its correlation with melt treatment in direct-chill casted hot rolling slabs.

In this study, different melt treatment operations were evaluated and compared to end product's scrap rate using bifilm index (B_I) method. Results clearly show that degassing with finer gas bubbles increases cleaning performance for the removal of any type of bifilms in the melt. B_I method is a reliable and quick way to determine melt quality at any given time during casting process which is found to have a direct correlation with rejection rate. [ABSTRACT FROM AUTHOR]