摘要
研究了Ｆｅ－１５Ｎｂ和Ｆｅ－３０Ｎｂ（Ｗｔ％）合金在６００～８００℃低氧压气氛中的氧化行为，实验所用的氧压处于煤的气化气氛下的氧分压范围。氧化后合金仅发生了Ｎｂ的内氧化，生成Ｎｂ２与Ｎｂ２Ｏ５，有些情况下还生成ＦｅＮｂ２Ｏ６。在６００℃时氧化速度很低，但在７００～８００℃时则颇高。这些合金内氧化的重要特征之一，是其内氧化物的分布几乎完全与合金中的高含Ｎｂ相一致。此外，合金氧化后均不出现外氧化层。这些可能都是由于Ｎｂ在Ｆｅ中溶解度很低且合金呈两相组织所致。
he oxidation of two Fe-Nb alloys containing 15 and 30 wt% Nb respectively was studied at 600￣800℃finder low oxygen pressures, similar to the environments prevailing in coal gasification. The main reaction was internal oxidation of niobium with the formation of niobium oxides (NbO2 and Nb2O5) and in some cases of a double Fe-Nb oxide. The kinetics of this reaction was very slow at 600℃ but rather fast at 700and 800℃. A peculiar feature of the internal oxidation of these alloys was that the distribution of the internal oxides was the same as that of the Nb-rich phase in the original two-phase alloys. This behavior and the lack of formation of external scales of niobium oxides were mainly the result of the limited solubility of niobium in iron and of the consequent. presence of two phases in the alloys under examination.
出处
《中国腐蚀与防护学报》
CAS
CSCD
1996年第2期107-114,共8页
Journal of Chinese Society For Corrosion and Protection
关键词
高温
氧化
低氧压
铁铌合金
Fe-Nb alloys, High temperature, Oxidation, Low oxygen pressure
