Evolution and mechanism of dissolutive wetting between hot metal and carbon brick

Abstract

The dissolutive wetting between hot metal and carbon brick is a complex problem from the viewpoint of carbon brick erosion. The current work aims to clarify the mechanism of dissolutive wetting at the interface between hot metal and carbon brick. The interfacial morphology is analyzed using SEM and EDS, and the change in wetting angle is studied using CCD camera and ImageJ software. Also, the interface shape model is established, the coupling control mechanism of dissolution and wetting is explored. The results reveal that the concave-like interface is formed after dissolutive wetting and the concave depth decreases with the increase of carbon content in hot metal. Moreover, a large amount of graphite flakes appear at the interface between hot metal and carbon brick after dissolutive wetting. The upper wetting angle initially exhibits a rapid decrease with time, followed by a gradual decrease. The lower wetting angle increases with time. The overall wetting angle initially decreases with time, followed by a stable trend. Hence, the dissolutive wetting can be divided into two stages.Furthermore, the interface shape model is established based on the scaling law and Noyes-Whitney equation to describe the dissolutive wetting. The variation of interface shape can be obtained by the interface shape model. The governing equation is obtained through the Onsager principle to clarify the coupling control mechanism of dissolutive wetting. Finally, wetting is determined by the relative situation of interfacial energy and dissolution free energy. The liquid structure of hot metal is changed due to the migration of carbon atoms from carbon brick to hot metal during dissolutive wetting, altering the free energy and facilitating the transition from the first stage to the second stage.