摘要
研究了含３０ｗｔ．％Ｃｅ的Ｆｅ－Ｃｅ合金在６００～８００℃、Ｈ２／Ｈ２Ｓ混合气中的腐蚀行为，其硫的分压为１．０１×１０－３Ｐａ。结果表明，Ｆｅ－３０Ｃｅ合金的腐蚀速度比纯Ｆｅ慢得多，但比纯Ｃｅ快得多，随温度升高其腐蚀速度加快。该合金硫化后形成复杂的腐蚀产物膜，最外层为纯Ｆｅ的硫化物层，其下为Ｃｅ的硫化物与Ｆｅ的硫化物的混合物层，内层为Ｃｅ的内硫化区，与之相邻的基体金属层中没有贫Ｃｅ现象发生，Ｃｅ不能从合金的腐蚀区中扩散出去，而是在腐蚀区中形成Ｃｅ的硫化物与Ｆｅ的硫化物的混合物。尽管与纯Ｆｅ相比，Ｆｅ－Ｃｅ合金的腐蚀速度下降了，但在合金的表面上仍形成了连续的ＦｅＳ层，可见，３０ｗｔ．％的Ｃｅ亦不足以阻止基体金属的腐蚀，以及复杂氧化膜结构的形成，可能与Ｃｅ在基体金属中有限的溶解度及合金中金属间化合物相的出现有关。
The corrosion behavior of Fe Ce alloy containing approximately 30 wt.% cerium has been studied at 600～800℃ in H 2/H 2S mixed gas providing a sulfur pressure of 1 01×10 -3 Pa.The alloy corrodes more slowly than pure Fe,but more rapidly than pure cerium,the corrosion rate of the alloy generally increases with temperature.The corrosion of the alloy produces complex scales,containing an outmost layer of practically pure iron sulfide and an inner layer where the sulfides of both alloy components are simultaneously present and a thin region of intermal sulfidation of cerium in contact with the alloy which is not depleted in cerium.The iron sulfide forms a continuous FeS layer on the suface of the alloy,even though at rates reduced with respect to prue iron.Thus,a cerium content of 30 wt.% is not sufficient to prevent the sulfidation of pure iron.These results and the details of the microstructure of the scales grown on the alloy are interpreted by taking into account the limited solubility of cerium in the base metal and the presence of intermetallic compounds in the alloy.
出处
《稀土》
EI
CAS
CSCD
北大核心
1998年第4期20-25,共6页
Chinese Rare Earths
基金
欧共体研究合作项目
