活性元素Y和Ce对Fe-25Cr-40Ni合金高温氧化的影响  

EFFECT OF REACTIVE ELEMENTS Y AND Ce ON HIGH TEMPERATURE OXIDATION OF Fe-25Cr-40Ni ALLOY

作　　者：俞方华[1] 杨国华[1] 韩荣典[2] 翁惠民[2] 沈嘉年[3] 

机构地区：[1]中国科学院上海原子核研究所 [2]中国科学技术大学 [3]中国科学院金属腐蚀与防护研究所腐蚀科学开放研究实验室

出　　处：《金属学报》1992年第4期B145-B153,共9页Acta Metallurgica Sinica

基　　金：中国科学院金属腐蚀;防护研究所腐蚀科学开放研究室资助课题

摘　　要：用离子背散射和慢正电子束研究了活性元素Y和Ce对Fe-25Cr—40Ni合金在高温初期氧化动力学、氧化膜表层成份和微观缺陷结构的影响,实验结果表明了微量活性元素(≥0.05%)在高温氧化初期显著减少了合金的氧化速率,有效地促进了Cr_2O_3的生长,抑制了Fe和Ni氧化物的形成,改善了氧化膜的微观结构,活性元素结合进入氧化膜并在外层膜中(约几十nm)富集,活性元素Ce抗氧化机理不同于Y,Ce使合金氧化膜的空位缺陷显著降低,主要控制了阳离子沿晶格空位向外扩散,而含Y合金由氧化初期主要控制阳离子沿晶格扩散转变为主要控制阳离子沿晶界向外扩散。Effect of reactive elements Y and Ce on high temperature oxidation of Fe-25Cr-40Ni alloy as well as on composition and microstructure of oxidized layer has been studied by ion backscattering and slow positron beam. The reactive element, not more than 0.05%, may decrease the oxidation rate at early stage, accelerate the Cr_2O_3 growth, retard the Fe and Ni oxides formation and improve the microstructure of oxidized layer. They enter the oxidized layer and concentrate within several tens nm from surface of outer layer. The resistance mechanism to oxidation for Ce seems to be different from Y. Ce may decrease the density of va- cancy defects in oxidized layer so that the diffusion outward of cations through vacancies is re- strained. While Y may affect the restraint of cations diffusion outward through vacancies at ear- ly stage to change into that along grain boundaries.

关 键 词：高温 氧化 活性元素 FeCrNi合金 

分 类 号：TG133.4[一般工业技术—材料科学与工程]