With using the macro examination method for macro structure of casting bloom and the analysis technology for metal original position statistic distribution the effect of mold electromagnetic stirring current (200-450 A

3 Hz) on equiaxed crystal zone rate

density fraction and carbon segregation of Φ650 mm heavy round casting bloom of 0.35C steel produced at steelworks has been studied. Test results show that with stirring frequency 3 Hz as current increases from 200 A to 450 A

the equiaxed crystal zone rate increases from 24.2% to 56. 8% while the density fraction of each zone in casting bloom increases gradually and the density fraction at center zone of casting bloom increases obviously i. e. from 0.8649 increasing to 0.9376

and with increasing stirring current the carbon segregation of easting bloom occurs the trend to lighten. Comprehensively considering each factor

as mold electromagnetic stirring current is 450A with frequency 3 Hz the equiaxed crystal zone rate in bloom is largest and the internal quality of bloom is best.