Fe—Y合金在600—800℃空气中的氧化行为

研究了Ｆｅ－Ｙ合金及纯Ｆｅ在６００～８００℃空气中氧化行为，纯Ｆｅ在三个温度下的氧化均符合抛物线规律，Ｆｅ－Ｙ合金的氧化除在５００℃挖主符合抛物线规律外，共作弊是呈阶段性变化，Ｆｅ－Ｙ合金氧化速度明显低于纯Ｆｅ，在７００～８００℃情况下，Ｆｅ－Ｙ合金表面形成外层为Ｆｅ的氧化物（Ｆｅ２Ｏ３，Ｆｅ３Ｏ４和ＦｅＯ），以为ＦｅＯ和ＹＦｅＯ３的混合物的氧化膜结构，在６００℃下，氧化产物主要为Ｆｅ２Ｏ3、Ｆｅ3O4和Y2O3.其中FeO在Fe的氧化物中所占比例较小.在三个温度下,Fe-Y合金均发生明显的内氧化.讨论了Y对Fe-Y合金氧化行为的影响.

OXIDATION OF Fe-Y ALLOYS AT 600-800'C IN AIR

The oxidation behaviors of Fe-Y alloys containing 2at% and 5at. %Y respec- tively and pure iron have been studied at 600--800'C in air. Fe-2Y and Fe-5Y alloys were oxidized slower than pure Fe at the three temperatures. The oxidation of pure iron followed a parabolic rate law. The oxidation of Fe-Y alloys at 600'C followed an approximately parabolic rate law, but not at 700 and 800'C where the oxidation went through several stages with quite different rates. The oxide scales grown on Fe-2Y and Fe-5Y alloys at 700 and 800'C were composed of an external pure Fe oxides containing Fe203, Fe304 and FeO among which FeO constituted the main iron oxides, and an inner mixture of ,FeO and YFeO,. The scales grown on Fe-2Y and Fe-5Y at 600'C mainly consisted of Fe203, Fe,04 and Y203 with little FeO. Significant internal oxidation in both Fe-Y alloys was observed at the three tem- peratures. The Y-containing oxides followed the distribution of the original intermetallic compound phase in the alloys. The effects of Y on the oxidation of pure Fe are discussed.