A MODIFIED MODEL USED TO DESCRIBE AUSTEN-ITE/MARTENSITE INTERFACE

Abstract

A new method (electromagnetic steel-teeming method) using electromagnetic induc- tion heating in slide-gate was proposed to overcome the disadvantage of the pollution of the traditional nozzle sand on the molten steel. The basic idea of this new process is to melt part or whole of the new ladle well-packing material (i.e. Fe-C alloy with similar composition of the molten steel), which becomes the substitute of the traditional nozzle sand, and achieve smoothly molten steel-teeming. In the experiment, the state of the Fe-C alloy well-packed in the upper nozzle was examined when the ladle held molten steel using the self-designed electromagnetic steel-teeming simulation facility. The results showed that the Fe-C alloy in the upper nozzle were divided into liquid Fe-C alloy, solidified Fe-C alloy, liquid-sintered, solid-sintered and original layers. The solidified, liquid-sintered and solid-sintered layers could prevent the molten steel flow into the upper nozzle from destroing the slide plate. The blocking layers could be melted with induction heating to achieve electromagnetic steel- teeming. In addition, the position of the liquid/solid interface of the Fe-C alloy in the upper nozzle was investigated. The length of liquid Fe-C alloy increased with the increase of time after molten steel poured into the ladle and then kept in a certain length. Furthermore, the position of the interface increased with the increase of melting points which were related to the composition of the Fe-C alloy.