AOD炉渣对MgO-C砖的侵蚀机理研究

不锈钢生产主要采用氩氧精炼(AOD)炉冶炼工艺,本文探究AOD炉渣对钢包内衬用MgO-C砖的侵蚀机理,为提高钢包内衬用MgO-C砖的使用性能和服役寿命提供理论支撑。结合FactSage6.2软件、X射线衍射(XRD)、场发射扫描电子显微镜(SEM)和能量色散光谱(EDS)等测试手段分析炉渣侵蚀后MgO-C砖的物相变化、显微结构和化学成分变化。结果表明,随着侵蚀反应的进行,方镁石逐渐被熔蚀,且逐步出现Ca₃MgSi₂O₈等低熔点物相,以及MgAl₂O₄等高熔点物相。AOD炉渣通过基质部分侵蚀渗透MgO-C砖,并与方镁石反应生成Ca₃MgSi₂O₈等低熔点物相,熔蚀方镁石;同时,方镁石边界处生成MgAl₂O₄,阻碍AOD炉渣对MgO-C砖的侵蚀渗透。

Study on Corrosion Mechanism of AOD Slag on MgO-C Brick

The argon oxygen decarburization (AOD) furnace smelting process is widely used in the stainless-steel production. The corrosion mechanism of AOD slag to MgO-C bricks used by ladle lining was studied to provide theoretical basis for improving the service life and performance of MgO-C bricks used by ladle lining. The phase change, microstructure and chemical composition change of MgO-C bricks after corrosion were analyzed by FactSage6.2 software, X-ray diffraction (XRD), field emission scanning electron microscope (SEM) and energy dispersion spectrum (EDS). The results show that, as the corrosion reaction proceeds, periclase is gradually eroded, and the low melting point phases such as Ca₃MgSi₂O₈ and the high melting point phases such as MgAl₂O₄ gradually appear. The corrosion is resulted by the penetration of AOD slag through the matrix in the MgO-C bricks, and the reaction between slag and periclase to form Ca₃MgSi₂O₈. The generation of MgAl₂O₄ at the boundary of periclase hinders the corrosion of AOD slag to MgO-C bricks.