Distribution of nonmetallic inclusions in molten steel under hot-top pulsed magneto-oscillation treatment

Abstract

To control the distribution of nonmetallic inclusions in molten steel is of highly commercial importance. A newly developed method, hot-top pulsed magneto-oscillation (HPMO), was employed to control nonmetallic inclusions in a medium-carbon steel ingot. The experimental results present that the position of nonmetallic inclusions of spinel (Al–Mg–O) and Mn–S inclusions is significantly influenced by HPMO. The number of nonmetallic inclusions gradually increased from the lateral wall to the center of ingot along the radial direction under the impact of HPMO treatment, whereas this distribution trend cannot be observed in the reference sample without HPMO treatment. In addition, the number of inclusions along vertical direction is proportional to the height of ingot, especially for the inclusions with the size of larger than 10 μm. It indicates that the application of HPMO can push away inclusions from lateral to center, and then the expelled inclusions aggregate and rise up to the top of ingot.