Study on the effect of pulsed current on the erosion of refractory material by rare earth steel liquid

As an important functional refractory material connecting the intermediate ladle and the crystallizer, the safe and stable operation of the submerged entry nozzle is of great significance to the continuous casting process. However, with the promotion of high-quality application of rare earth in steel, it is found that the casting of rare earth steel very easily causes caking and clogging of submerged entry nozzles. In this paper, with Al₂O₃-C quality refractory material as the experimental object, the effect of pulsed current on the rare earth steel erosion refractory material was studied, and the mechanism of its action on the interfacial reaction of the refractory material erosion layer was explored. The results show that the surface structure of regular erosion-treated refractory material is severely eroded and damaged due to a decarburization reaction, resulting in a rough and porous interface and unevenness. While under the action of pulsed current, the surface structure of refractory material is more flat, smooth and dense, with the preservation of particles intact and no apparent inclusions adsorbed, mainly because the surface of Al₂O₃, SiO₂ and RE₂O₃ will react to generate the initial product Ce₄Si₅Al₅O_23.5 to retard the decarburization rate of graphite and inhibit the erosion of steel on the refractory material, in which the average thickness of the erosion layer is reduced the most when immersed for 30 min, up to 67.6%.