低碳镁碳质耐火材料的抗氧化性研究

Investigation on oxidation resistance of low-carbon MgO-C refractories

比较了石墨含量(质量分数)分别为0、2%、4%、6%和12%的镁碳试样氧化后的质量损失率和脱碳层厚度,并用XRD分析了氧化后试样脱碳部位和未脱碳部位的物相组成,用金相显微镜观察了氧化后试样的形貌.结果表明:质量损失率与石墨含量成正比,石墨含量增加,质量损失率变大;石墨含量低的试样脱碳层厚度比较接近,脱碳层厚度为4～5 mm,比石墨含量为12%的镁碳材料脱碳层厚度小一半,具有明显的抗氧化性能.

The oxidation mass loss rate and the thickness of decarbonized layer of MgO-C specimen with 0,2%, 4% ,6% and 12% graphite respectively were comparatively studied. The phase compositions of decarbonized part and undecarbonized part of the specimens were analyzed by XRD,and the microstructure of oxidized specimens was observed with microscope. The result showed that there was a direct ratio between the oxidation mass loss rate and the graphite content,that is to say,the oxidation mass loss rate increases with the graphite content increase. The thickness of decarbonized layer of specimens with low graphite content was about 4-5 mm, while the thickness of decarbonized layer of specimens with high graphite content was about 8 mm,showing that low-carbon specimens had high oxidation resistance.