Abstract: In view of the deterioration of slab quality and the decrease of the continuous casting efficiency caused by the serious corrosion at the slag line of submerged entry nozzles,taking the ZrO₂-C refractory material in the slag line of the submerged entry nozzle as the research object,the dissolution behavior and oxidation characteristics of the ZrO₂-C material in molten steel under the action of applied electric field were systematically studied.The effect of different polarities (positive and negative) and different voltages (0,1.5,3,and 4.5 V) under direct current electric field on the decarburization reaction of the ZrO₂-C material was compared and analyzed.The results show that (1)the application of the electric field affects the activity of graphite,and then changes the corrosion resistance of the slag line;(2)when the positive electric field is applied to the ZrO₂-C material,graphite is more likely to lose electrons and undergoes dissolution and oxidation reactions under the electric field force,promoting the decarburization of the material;the thickness of the decarburized layer gradually increases with the increasing voltage;when the negative electric field is applied,the alloy elements in molten steel gradually deposit on the slag line surface under the electric field force and electrostatic force,forming a dense Al₂O₃ enrichment layer on the surface,which effectively inhibits the decarburization of ZrO₂-C material,and the thickness of the decarburized layer reduces with the increasing voltage;(3)when a voltage of 3 V is applied,the decarburization thickness of the samples under both the positive and negative electric fields is the optimal overall.

Key words: applied electric field, continuous casting, submerged entry nozzle, ZrO₂-C material, decarburization reaction

摘要： 针对连铸过程中浸入式水口渣线部位的严重侵蚀导致铸坯质量恶化,连铸效率降低等问题,以浸入式水口渣线部位的ZrO₂-C耐火材料为研究对象,系统性研究了外加电场作用下ZrO₂-C材料在钢液中的溶解行为和氧化特征,并对比分析了直流电场下不同极性(正电场、负电场)和不同电压(0 、1.5 、3 、4.5 V)对ZrO₂-C材料脱碳反应的影响规律。结果表明:1)施加电场可以影响ZrO₂-C材料中石墨的活性,进而影响浸入式水口渣线的抗侵蚀性。2)当对ZrO₂-C材料施加正电场时,石墨在电场力的作用下更容易失去电子发生溶解及氧化反应,促进材料脱碳,脱碳层厚度随着电压的增加逐渐增大;施加负电场时,钢液中的合金元素在电场力及静电力的作用下逐渐向渣线表面沉积,表面形成致密的Al₂O₃富集层,可有效抑制ZrO₂-C材料表面的脱碳,脱碳层厚度随着电压的增加逐渐减小。3)当施加3 V电压时,正电场下试样和负电场下试样的脱碳层厚度整体上最优。

关键词: 外加电场, 连铸, 浸入式水口, ZrO₂-C材料, 脱碳反应