钢包渣线镁碳砖的侵蚀机理分析  

Erosion analysis of MgO-C refractory brick at the slag line of ladle

作　　者：沈平[1] 张立峰[1] 王祎[1] 杨文[1] 

机构地区：[1]北京科技大学冶金与生态工程学院,北京100083

出　　处：《炼钢》2016年第5期54-61,共8页Steelmaking

基　　金：中国自然科学基金资助项目(51274034;51334002;51404019;51504020)

摘　　要：对某钢厂LF精炼钢包渣线服役前后的镁碳砖进行理化分析、扫描电镜(SEM)-能谱分析(EDS)、Factsage热力学计算、润湿性分析等,研究了镁碳砖的侵蚀机理。研究表明,镁碳砖在钢包内不同的服役温度区域及其自身内部的不同组织结构造成其损毁及侵蚀机理的不同。在近钢液面的高温区域,镁碳砖自身会发生MgO与碳的反应,形成脱碳层。高温下熔渣与镁碳砖的润湿性更好且MgO向熔渣溶解的趋势更大,相比近空气侧的低温区域,镁碳砖受熔渣侵蚀更严重。镁碳砖中,不同MgO骨料颗粒其内部杂质相及组织结构有一定区别。熔渣与镁碳砖中的MgO组元间的润湿性较好,熔渣易对杂质相多、MgO晶粒尺寸较小的骨料进行侵蚀,且易沿MgO晶界渗入MgO骨料内部,造成MgO骨料颗粒的解离并进一步发生反应生成Mg2 SiO4。熔渣与镁碳砖之间的氧化还原反应也是其损毁的成因之一。Physical and chemical analysis, SEM-EDS detection, Factsage calculation, wettability analysis of the MgO-C refractory bricks at the slag line of ladle in LF refining before and after service were analyzed, and the erosion mechanism of MgO-C refractory brick was studied. The results showed that, the different temperature of the area where the MgO-C brick locates and the different structure of the MgO-C brick led to the different wear mechanism of refractory. In the hotter area closing to the molten steel, the MgO could react with C and formed a decarburization layer. The wettability between molten slag and MgO-C refractory brick was much better, and the solubility of MgO in the molten slag was much greater; Compared with the cooler area closing to the air, the erosion of MgO-C refractory brick was much serious in the hotter area. There were some differences of the impurity composition and structure between each MgO aggregate. The MgO aggregate with more impurity and small scale of MgO grain would be eroded more easily by molten slag for the good wettability between molten slag and MgO component. The molten slag would penetrate into the MgO aggregate through the grain boundaries, causing the disaggregation of MgO aggregate and the generation of Mg2 SiO4 by further reaction. Besides, the redox reaction between molten slag and MgO-C refractory brick was also the cause of the wear of refractory.

关 键 词：镁碳砖 侵蚀 MgO溶解度 润湿性 

分 类 号：TF769.2[冶金工程—钢铁冶金]