Influence of Mold Electromagnetic Stirring on Carbon Segregation on Continuously Cast Blooms of Bearing Steel

As metallurgical targets of mold electromagnetic stirring(M-EMS) in continuous casting of bloom for bearing steel were not fully achieved in Nanjing steel,experiments for optimizing process parameters of M-EMS were carried out.Carbon segregation of cast bloom and rolled products at different electromagnetic stirring parameters and stirring patterns was studied.The results show that there is negative segregation in the core and edge of bloom,and positive segregation in the 1/4x bloom,with the carbon segregation index of 320 mm×480 mm bloom at 0.87~1.05;the carbon segregation index of rolled metal is at 0.94~1.03.Positively and negatively alternating electromagnetic stirring is helpful to reduce the carbon segregation.When electromagnetic stirring current is relatively strong,negative segregation is severer in the core,and with the increase of the stirring electric current,the white zone moves to the bloom center and its width increases.The carbon segregation hands down from cast bloom to its rolled products.