New insight into crack formation during corrosion of zirconium-based metal-oxide systems
New insight into crack formation during corrosion of zirconium-based metal-oxide systems
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DOI：
10.1016/j.actamat.2013.04.009
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发表时间：
2013-07-01
期刊：
影响因子：
9.4
通讯作者：
Brechet, Yves
中科院分区：
文献类型：
--
作者：
Vermaak, Natasha;Parry, Guillaume;Brechet, Yves
锆合金通常在核压水反应堆（PWR）中用作燃料包壳管，这是由于它们的化学稳定性和它们在操作温度（约300摄氏度）下的机械强度。然而，锆基包壳管的腐蚀是限制压水堆燃耗速率的因素之一。人们普遍认为，腐蚀动力学涉及周期性的连续生长，其中氧化物厚度随时间呈抛物线变化。当氧化物变厚时，就会形成裂纹结构。氧化物呈现条纹状，具有平行于金属/氧化物界面的周期性裂纹层。这种开裂结构已实验相关的氧化物生长的周期性。在目前的工作中，有限元研究被用来调查的氧化物中的应力的发展下的氧化物形成，金属/氧化物界面的几何形状和金属基板蠕变的摩尔体积膨胀的综合影响。能够启动实验观察到的裂纹的拉伸应力的产生进行了探讨。(C)2013 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
Zirconium alloys are typically used in nuclear pressurized water reactors (PWR) as fuel cladding tubes due to their chemical stability and their mechanical strength at operating temperatures (approximate to 300 degrees C). However, the corrosion of Zr-based cladding tubes is one of the factors limiting the burn-off rate in PWRs. It is commonly accepted that the corrosion kinetics involves a periodic succession of growth where the oxide thickness varies parabolically with time. As the oxide thickens, a cracking structure forms. The oxide appears striated with periodic layers of cracks running parallel to the metal/oxide interface. This cracking structure has been experimentally related to the periodicity of the oxide growth. In the present work, a finite-element study is used to investigate the development of stresses in the oxide under the combined influence of molar volume expansion during oxide formation, metal/oxide interface geometry and metallic substrate creep. The generation of tensile stresses capable of initiating the cracks that are observed experimentally is explored. (C) 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.