锆锡合金腐蚀转折机理的讨论  

Discussion on Corrosion Transition Mechanism of Zircaloy

作　　者：刘文庆[1] 李强[1] 周邦新[1] 

机构地区：[1]上海大学,上海200072

出　　处：《稀有金属材料与工程》2001年第2期81-84,共4页Rare Metal Materials and Engineering

基　　金：核工业科学基金资助项目(Y7196E5101)

摘　　要：关于 Ｚｒ－２和 Ｚｒ－４合金的转折机理有多种假说，其中相变假说认为：锆合金的氧化速度主要受氧化物／金属界面附近 ｔ－ＺｒＯ２向 ｍ－ＺｒＯ２转变的控制。在 ４００℃， １０．３ ＭＰａ过热蒸汽中，相变是由应力松驰引起的；在 ３００℃的ＬｉＯＨ水溶液中，ＯＨ与氧空位的相互作用促使ｔ－ＺｒＯ２向ｍ－ＺｒＯ２转变。本文着重讨论了相变假说及其相变机理，最后提出了自己的观点：氧化膜中压应力达到一定值时，以及Ｌｉ＋进入氧化膜使其力学性能恶化可能导致氧化膜的碎裂，由此引起腐蚀加速和出现转折。Several hypotheses on the corrosion transition phenomenon of zircaloy are presented. Among those, the phase transformation mechanism suggests that the oxide growth rate of zircaloy is mainly controlled by the transformation from t-ZrO(2) to m-ZrO(2) near the oxide/metal interface, and the t-m transfomation is enhanced due to stress relaxation in 400 degreesC, 10.3 MPa superheated steam or triggered by the interaction of OH(-) with oxygen vacanices in 300 degreesC aqueous lithium hydroxide solution. More attention is paid to this hypothesis and the mechanism is discussed in this papier. Lastly, authors' view is put forwards: the break of the barrier leger of oxide-film, which may be caused by the compressive stress reaching a definite value or the degradation of its mechanical properties because of the lithium coming into the oxide film, will bring about the corrosion acceleration and transition phenomenon.

关 键 词：锆合金 腐蚀 转折 相变 反应堆 燃料包壳 

分 类 号：TG174.3[金属学及工艺—金属表面处理]