冲击对蒸汽发生器传热管微动磨损行为的影响研究

目的 研究冲击对核电站蒸汽发生器传热管在高温蒸汽环境中微动磨损行为的影响规律与机理。方法 采用高温高压蒸汽环境冲击–滑移与纯滑移对比试验，研究冲击对蒸汽发生器690TT合金传热管微动磨损行为的影响。通过分析微观损伤结构区别，对比高、低磨损能量试验结果，明确冲击在微动磨损中的作用，获得传热管冲击–滑移复合微动磨损机理。结果 高温高压蒸汽环境中，复合微动磨损与纯滑移微动磨损相比，没有犁沟磨损特征，剥层特征占主导地位，微动磨损机制为剥层磨损。磨损能量越高，冲击引起的磨屑层脱落和基体开裂越多，磨损越严重。结论 冲击显著改变了传热管的微动磨损行为，在开展传热管服役安全评估中，应充分考虑纯滑移磨损与冲击–滑移复合微动磨损的显著差异。

Effects of Impact on the Fretting Wear Behavior of Steam Generator Tubes

The work aims to study the effects of impact on the fretting wear behavior of steam generator (SG) tubes in the nuclear power plants. Comparative tests of impact-sliding and pure sliding fretting wear were performed in the high temperature and high pressure steam to investigate the effects of impact on the fretting ear behavior of 690TT alloy SG tubes. By analyzing the difference of the microscopic damage structures and comparing the test results of low wear work and high wear work, the role of impact on fretting wear was clarified, and the impact-sliding fretting wear mechanism of the tubes was obtained. In high temperature and high pressure steam, compared with the pure sliding fretting wear, the impact-sliding fretting wear showed dominate characteristics of delamination without obvious furrow wear, indicating a delamination wear mechanism. The higher the wear work, the more the fallen-off wear debris layer and the matrix cracking caused by the impact, and the more serious the impact-sliding fretting wear. Impact changes the fretting wear behavior of SG tubes significantly. Accordingly, the different wear conditions of pure sliding and impact-sliding should be fully considered during the service assessment of SG tubes.