Effect of position and height of liquid slag nozzle on steel-slag flow behavior in continuous casting mold

Abstract

The reaction between Mn and Al in molten steel and SiO 2 in the protective slag generates MnO and Al 2 O 3 , which can cause drastic changes in the composition of the protective slag, deteriorate the quality of the casting billet, and hinder the continuous casting process. The present work proposed a new idea of adding low-reactive liquid protective slag to respond to this bottleneck. Both water model experiment and numerical simulation were carried out to investigate the influence of height and position of the slag nozzle on the flow behavior of liquid slag in the initial stage of continuous casting using a slab mold (1,050 mm×135 mm). The results show that the turbulence kinetic at the steel-slag interface is the largest when the slag nozzle height is set to 150 mm and its position is 131.25 mm away from the narrow face of the mold, and the variance value of liquid level height is 3.27×10 −4 . This enhanced agitation is contributed to the flotation of inclusions and removal of bubbles in molten steel. At this time, the liquid slag spreading area is the largest, about 45.72%. When the height of the slag nozzle is set to 200 mm, the turbulence kinetic energy of the liquid surface generated by the steel-slag interface is the highest, and the corresponding variance value of the liquid level height is 3.69×10 −4 . However, the variation of slag nozzle height has little effect on the ratio of liquid slag spreading area compared with the position of the slag nozzle.