310S耐热钢的高温氧化行为EI北大核心CSCD

采用静态氧化不连续增重法研究晶粒尺寸和成分存在差异的两种310S耐热钢(1#和2#)在800~1100℃下的氧化动力学与膜结构,比较两者的氧化性能差异,阐明氧化膜的生长机制和差异形成原因。结果表明:800~900℃时氧化膜均由富Si氧化层和富Cr氧化层组成,1#试样的氧化速率更低;1000℃时氧化膜中增加了Cr-Mn氧化物层并在1100℃时转变为Cr-Mn-Fe氧化层,并且两者的氧化速率接近;整体上2#试样的氧化膜在所有温度下更加致密、平整,黏附性更好,保护能力更强。特别在1100℃时,两者的富Cr氧化层和Cr-Mn-Fe氧化层的形态分化较大,2#试样的氧化膜形态更有利于长期的抗氧化性能。总体上,2#试样的抗氧化性优于1#试样。2#试样所具备的更小的平均晶粒尺寸和更均匀的晶粒提高了择优氧化元素的扩散通量并降低氧化膜的非均匀生长,造成两者氧化性能的差异。

High temperature oxidation behavior of 310S heat-resistant steel

The oxidation kinetics and film structure of two kinds of 310S heat-resistant steels (1^# and 2^#) with different grain sizes and composition at 800-1100 ℃ were studied by static oxidation discontinuous mass gain method. The differences of oxidation properties between the two steels were compared, and the growth mechanism of oxide film and the reasons for the differences were clarified. The results show that the oxide film is composed of Si-rich oxide layer and Cr-rich oxide layer and the oxidation rate of sample 1^# is lower at 800-900 ℃; Cr-Mn oxide layer is added to the oxide film at 1000 ℃ and is transformed into Cr-Mn-Fe oxide layer at 1100 ℃, and their oxidation rates are similar; on the whole, the oxide film of sample 2^# is denser, smoother, more adherent and more protective at all temperatures. Particularly, the spinel layer and the chromium oxide layer of the two are greatly different in the form at 1100 ℃, and the form of the oxide film of sample 2^# is more conducive to long-term oxidation resistance. In general, the oxidation resistance of sample 2^# is better than that of sample 1^#. The smaller average grain size and more uniform grain of sample 2^# improve the diffusion flux of preferred oxidation elements and reduce the uneven growth of oxide film, resulting in the differences of oxidation properties between the two.