Novel images of the evolution of stress corrosion cracks from corrosion pits
Novel images of the evolution of stress corrosion cracks from corrosion pits
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DOI：
10.1016/j.corsci.2011.05.050
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发表时间：
2011-11-01
影响因子：
8.3
通讯作者：
Turnbull, A.
中科院分区：
文献类型：
--
作者：
Horner, D. A.;Connolly, B. J.;Turnbull, A.
暴露于模拟蒸汽汇酸盐的涡轮盘钢中的SCC倾向于从腐蚀坑前体优先核定成核。这些裂缝的演变不是直接的，也不是很好的理解。在这项工作中，独特的三维X射线显微图像图像证实，裂纹主要在坑的肩部（坑/表面界面附近）出现，用于压力为50-90％Sigma（0.2）的标本。为了支持这种观察，模型坑的FEA表明，在坑口正下方的坑壁上是最大的应变。讨论了这些观察结果对裂缝成核和生长的预测过渡和预测模型的影响。 （c）2011 Elsevier Ltd.保留所有权利。
SCC in turbine disc steels exposed to simulated steam-condensate tends to nucleate preferentially from corrosion pit precursors. The evolution of these cracks is not straightforward and not well understood. In this work, unique three-dimensional X-ray microtomographic images have confirmed that cracks develop predominantly at the shoulder of the pit, near the pit/surface interface, for specimens stressed to 50-90% sigma(0.2). In support of this observation, FEA of model pits indicate that strain is a maximum on the pit wall just below the pit mouth. Implications of these observations for the pit-to-crack transition and predictive-modelling of crack nucleation and growth are discussed. (C) 2011 Elsevier Ltd. All rights reserved.