关键词: VOD钢包;低碳镁碳材料;渣线;侵蚀;石墨

Abstract: Based on the two kinds of low-carbon magnesia carbon refractories (LCMCR) containing with expanded graphite or micron-scale graphite as the main carbon resources , it 's degradations were investigated in VOD ladle slagline by industrial tests .The results indicated that MgO dense layer and slag infiltration dense layer were formed in the corrosion layer of the LCMCR containing with micron -scale graphite, but not in the corrosion layer of the LCMCR containing with expanded graphite due to the bigger pores originated by the oxidation of expanded graphites .The decarburizing reaction ( MgO-carbon reaction) under the VOD refining condition (high temperature, low pressure) and the direct burnout of the carbon in the LCMCR were inhibited due to the dense layers formed in corrosion layer , and the corrosion resistance could be improved as result .So the average corrosion rate of the LCMCR containing with expanded graphite was 45％ higher than the one containing with micron -scale graphite, and the corrosion mechanisms of the two kinds of LCMCRs were proposed .

Key words: VOD ladle;low-carbon magnesia carbon refractories;slagline;degradation;graphite