Fretting Wear Damage of tubular bundles in the presence of flow-induced vibrations at elevated temperatures

流激振动是核反应堆管道微动磨损、疲劳和开裂的主要原因之一。在过去的40年里，人们对压水堆蒸汽发生器支座的微动磨损进行了大量的研究。这些工作旨在预测流体引起的振动响应、管/支架的冲击力和磨损系数。使用这些量（响应、正常接触和磨损系数），可以预测磨损量，从而预测部件的年龄。对典型电抗器材料在工作条件下的微动磨损进行了较好的表征。虽然SMR的设计基于现有的部署技术，但其他设计则基于先进的概念，建议尺寸范围高达300兆瓦，温度范围超过850°C。此外，这些组件将在完全不同的环境下运行。此外，所提出的材料主要考虑了其保压特性和腐蚀性能。虽然对一些SMR材料（如800HT、Hastelloyx等）的强度和腐蚀性能有了合理的了解，但这些材料在高温和不同环境条件下的微动磨损特性仍是未知的。本项目旨在了解微动磨损退化机理，并以更高的置信度为高温下的性能提供指导。该项目解决了NSERC-CNSC小型模块化反应堆研究资助计划中“高温对反应堆组件的影响”下的研究挑战和知识空白。

Flow-induced vibrations is one of the main causes of fretting wear, fatigue, and cracking in tubes in nuclear reactors. There have been considerable work efforts in past 4 decades that aimed at predicting fretting wear at the supports in the pressurized water reactor steam generators. These efforts were directed at predicting the flow-induced vibrations response, tube/support impact forces and wear coefficients. Using these quantities (response, normal contact, and wear coefficients) one can predict the wear volume and consequently the age of the component. The fretting wear of typical reactors materials under operating conditions is well characterized. While SMR designs are based on existing deployed technologies, others are based on advanced concepts, suggesting a range of sizes up to 300 MWe and a range of temperatures of more than 850°C. In addition, the environment under which these components will operate are entirely different. Moreover, the proposed materials for the SMR are mainly considered for their pressure retaining characteristics and corrosion. While a reasonable knowledge of strength and corrosion performance is gained for some of the proposed SMR materials such as 800HT, Hastelloyx, etc. the fretting wear characteristics at these materials at high temperatures and different environmental conditions are unknown. This project aims at gaining an understanding of the fretting wear degradation mechanisms and providing guidance on the performance at high temperature with higher confidence. This project addresses the research challenges and knowledge gaps under "Consequences of high temperature on reactor components" in the NSERC-CNSC Small Modular Reactors Research Grant Initiative.