Fe-Y合金在600～800℃空气中的氧化行为

OXIDATION OF Fe\|Y ALLOYS AT 600～800℃ IN AIR

研究了 Ｆｅ Ｙ 合金及纯 Ｆｅ 在 ６００～８００℃空气中的氧化行为．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 ６００℃近似符合抛物线规律外，其余则呈阶段性变化． 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（ Ｆｅ２ Ｏ３， Ｆｅ３ Ｏ４ 和 Ｆｅ Ｏ），内层为 Ｆｅ Ｏ 和 Ｙ Ｆｅ Ｏ３ 的混合物的氧化膜结构．在 ６００℃下，氧化产物主要为 Ｆｅ２ Ｏ３、 Ｆｅ３ Ｏ４、 Ｆｅ Ｏ 和 Ｙ２ Ｏ３ ．其中 Ｆｅ Ｏ 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

The oxidation behaviors of Fe\|Y alloys containing 2at% and 5at.%Y respectively and pure iron have been studied at 600～800℃ 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℃ followed an approximately parabolic rate law, but not at 700 and 800℃ 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℃ were composed of an external pure Fe oxides containing Fe 2O 3, Fe 3O 4 and FeO among which FeO constituted the main iron oxides, and an inner mixture of FeO and YFeO 3. The scales grown on Fe\|2Y and Fe\|5Y at 600℃ mainly consisted of Fe 2O 3, Fe 3O 4 and Y 2O 3 with little FeO. Significant internal oxidation in both Fe\|Y alloys was observed at the three temperatures. 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.