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.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
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)