Abstract: As the demand for highcarbon 82A steel increase the improvement of internal quality such as center carbon segregation in rectangular bloom with the section size of 180 mm×240 mm, both final permanent magnetic stirring and final electromagnetic stirring (FEMS) were applied in a rectangular bloom caster. The results showed that the permanent magnet stirring provides an essential improvement in the internal quality of highcarbon rectangular blooms compared with the F-EMS. The mean center segregation degree of carbon was 1.06 with the permanent magnet stirring and 1.10with the F-EMS. Compared with the FEMS, the center segregation degree of carbon less than 1.05was increased by 40%, the grade of center porosity equals to 0.5was increased by 50 %and the grade of shrinkage cavity equals to 0 was increased by 20 %by adopting the permanent magnet stirring. Besides, the calculating results showed that the stirring velocity of the molten steel with permanent magnet stirring was 1.15 times that of F-EMS.

Key words: final permanent magnet stirring, final electromagnetic stirring, high carbon rectangular bloom, center carbon segregation, stirring velocity