The oxidation rates of several nuclear-grade graphites, NBG-18, NBG-17, IG-110 and IG-11, were measured in air using thermogravimetry. Kinetic parameters and oxidation behavior for each grade were compared by coke type, filler grain size and microstructure. The thickness of the oxidized layer for each grade was determined by layer peeling and direct density measurements. The results for NBG-17 and IG-11 were compared with those available in the literature and our recently reported results for NBG-18 and IG-110 oxidation in air. The finer-grained graphites IG-110 and IG-11 were more oxidized than medium-grained NBG-18 and NBG-17 because of deeper oxidant penetration, higher porosity and higher probability of available active sites. Variation in experimental conditions also had a marked effect on the reported kinetic parameters by several studies. Kinetic parameters such as activation energy and transition temperature were sensitive to air flow rates as well as sample size and geometry.

使用热重法在空气中测量了几种核级石墨NBG-18，NBG-17，IG-110和IG-11的氧化速率。通过焦炭类型，填料粒度和微观结构比较了每个等级的动力学参数和氧化行为。通过层剥离和直接密度测量来确定每个等级的氧化层的厚度。将NBG-17和IG-11的结果与文献中的结果进行了比较，并且我们最近报道了NBG-18和IG-110在空气中的氧化结果。较细颗粒的石墨IG-110和IG-11比中颗粒NBG-18和NBG-17的氧化程度更高，这是因为更深的氧化剂渗透，更高的孔隙率和更高的可用活性位点。实验条件的变化还对多项研究报告的动力学参数产生了显着影响。