Behavior of Argon Bubbles during Continuous Casting of Steel

Water model experiments, mathematical models, and plant data are analyzed to understand the behavior of argon bubbles during continuous casting of steel. Highspeed video pictures reveal how argon acts to protect the nozzle wall from alumina inclusions and clogging. Mathematical models reveal the importance of inclusion attachment to moving argon bubbles, as a means of inclusion removal into the mold slag. Bubble motion in the solidifying strand of a curved slab caster is simulated with a 3-D turbulent flow model. The predictions are evaluated using the results of studies on operating casters. Insights are gained into the causes of “pencil-pipe” and blister defects on the surface of the final product.