1. Effect of NaCl and SO2 on the stress corrosion cracking of CMSX-4 at 550°C
- Author
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F. Duarte Martinez, A. Syed, K. Dawson, G. J. Tatlock, N.I. Morar, M. Kothari, C. Tang, J. Leggett, J.C. Mason-Flucke, G. Gibson, J.R. Nicholls, S. Gray, and G.M. Castelluccio
- Subjects
cmsx-4 ,Mechanics of Materials ,Mechanical Engineering ,c-ring ,hot corrosion ,Materials Chemistry ,Metals and Alloys ,Ceramics and Composites ,Condensed Matter Physics ,factsage 8.1 - Abstract
In the pursuit of more efficient gas turbine engines, components are required to operate for longer times at elevated temperatures. This increased time in service, together with a complex loading regime, can expose the material to environmental attack. This work has demonstrated that the interaction of stress, NaCl and a sulphur-containing environment is critical to cause crack initiation in the early stages of the exposure and accelerated corrosion rates in CMSX-4 at 550°C. The effect of having small concentrations of moisture in the gaseous environment or as water crystallisation in the salt is still to be investigated. A working hypothesis is that the interaction of alkali chlorides with a sulphur-containing atmosphere is the trigger to a self-sustaining cycle where metal chloride formation, vaporisation and oxidation lead to high amounts of hydrogen injection in a rapid manner and, therefore, hydrogen embrittlement.
- Published
- 2023