The design of a typical steam generator involves contact between tubes and supporting plates within the shell of the generator. Flow-induced vibrations can cause tubes to impact and move against these supports and results in tube fretting-wear. The overall damage involves mechanical and corrosive wear and synergistic effects between those two are generally observed. Most of the work on fretting damage of Inconel-600 is directed towards predicting and preventing fretting wear alone, without much consideration of the corrosion factor. This necessitates more research to be done to understand the fretting-corrosion wear behaviour of this alloy in wide range of industrial applications. In this research project, the aspect of corrosion of two common materials of steam generator components has been investigated; Inconel-600 was coupled with stainless steel UN8 843100. Three in-situ electrochemical measurement techniques have been employed during fretting to investigate the synergistic effects between mechanical and chemical damage; Monitoring of the free corrosion potential, corrosion current density. Conducting of linear polarisation during fretting to study the role of various fretting parameters and test environments on the mechanical and electrochemical aspects of surface damage in three environments. Increasing the applied normal load has influenced the wear volume, Increasing the fretting period and displacement amplitude have found to increase the wear volume of Inconel-600 in all test environments. Lowering of the corrosion potential and increasing corrosion current was dependent on the applied normal load and vibration's amplitude within the contact area. Increasing the fretting period has been also found to increase the wear volume. Increasing the fretting period and the normal applied load were found to force the fretting regime to move from slip to stick conditions. The electrochemical response has shown dependency of the corrosion evolution on the fretting regime. In this work, the rates and mechanisms of fretting-corrosion wear of Incone-600 were discussed. Wyko surface profile meter and 8EM have been employed to assess the effect of varying fretting parameters on the mechanical and electrochemical aspects of the surface damage. And any suggested future work will be acknowledged.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:616297 |
| Date | January 2013 |
| Creators | Lgried, Mohamed Parka Sallem |
| Publisher | University of Leeds |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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