Effect of NaCl and SO₂ on the stress corrosion cracking of CMSX-4 at 550°C

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 material environmental attack. work has demonstrated that interaction stress, NaCl and sulphur-containing environment is critical cause crack initiation early stages exposure accelerated corrosion rates CMSX-4 550°C. The effect having small concentrations moisture gaseous or as water crystallisation salt still be investigated. A working hypothesis alkali chlorides atmosphere trigger self-sustaining cycle where metal chloride formation, vaporisation oxidation lead high amounts hydrogen injection rapid manner and, therefore, embrittlement.