MgO-Al2O3-C材料服役状态下MgO致密层的形成机理

一种SiC含量为6.0％的MgO-Al2O3-C(MAC)材料被用于精炼钢包包壁部位,表现出优异的抗侵蚀性能,对用后MAC材料的物相组成和显微结构进行分析.结果显示,在MAC材料侵蚀界面形成MgO致密层,提高了MAC材料的抗侵蚀性能.MAC材料内的SiC,一方面与MgO反应形成更多的Mg(g);另一方面,SiC氧化后形成的部分SiO2进入侵蚀层熔渣使熔渣碱度下降,粘度大幅上升,不但提高了MgO在熔渣中的形成速率,而且同时降低了MgO的溶解速率,促进MgO再结晶和MgO致密层的形成.

Formation Mechanisms of MgO Dense Layer in Corrosion Interface of MgO-Al2O3-C Refractory in Service State

A kind of MgO-Al2O3-C (MAC) refractory with 6.0wt％ SiC was tested in the sidewall of the refining ladle,which performed the excellent corrosion resistance,and the phase compositions and the microstructures of the used MAC refractory were investigated.The results indicate that the formation of MgO dense layer in the corrosion interface of MAC refractory improves the corrosion resistance.The reaction of SiC with MgO continuously accelerates the generating of the Mg (g) in the MAC refractory during the service environment.On the other hand,a part of SiO2 originating from the oxidized SiC entered into the slag of the corrosion interface,which make the basicity of the slag decrease and the viscosity raise,and the recystallization of MgO will be promoted.The two aspects of the SiC synthetically contribute to the formation of the MgO dense layer.