高炉炉缸凝铁层物相分析

在高炉炉缸破损调研的基础上对高炉炉缸耐火材料热面凝铁层进行取样,利用扫描电子显微镜、物相分析等分析手段揭示了凝铁层的物相组成,并运用Thermol-calc热力学计算软件结合TCFE8数据库对铁水中石墨碳的析出温度及析出相分数进行了计算,最后揭示了炉缸凝铁层物相的形成机理.结果表明,高炉炉缸凝铁层主要由Fe相和石墨碳相交替分布组成,铁水成分对石墨碳析出温度影响较大,石墨碳析出温度远高于铁水凝固温度,铁水中C、Si元素含量对石墨碳析出相分数影响较大,而石墨碳析出相可增大铁水黏度11.9%.凝铁层中石墨碳的析出主要是由于Fe-耐火材料界面温度低于石墨碳析出温度,使得铁水中C不断向耐火材料热面迁移,进而形成Fe-C交替的分层结构.

Analysis of the phase of the solid iron layer in blast furnace hearth

The solidified iron layer in blast furnace ( BF) hearth was estimated based on the blast furnace damage. The phase compositions of the solidified iron layer were studied using scanning electron microscope and energy dispersive spectrometer. The tem-perature and proportions of graphite precipitation were calculated by using the Thermol-calc software and the TCFE8 database. Final-ly, the formation of the solidified iron layer was examined. The results suggest that the solidified iron comprises iron and graphite. The temperature of the graphite precipitation is affected by the composition of the hot metal, and it is much higher than the solidification temperature of the hot metal. The proportions of precipitated graphite are affected by the C and Si in the hot metal, whereas the precip-itated graphite increases the viscosity of the hot metal by 11. 9%. The graphite precipitates at the interface with the Fe- refractory at lower temperature than that of the graphite saturation, which allows the C migration from the hot metal to the refractory interface.