Corrosion of the alloys Magnox AL80, Magnox ZR55 and pure magnesium in air containing water vapour

Understanding the corrosion susceptibility of Magnox alloys during short- and long-term storage in moist air is important. Corrosion of Magnox AL80, Magnox ZR55 and magnesium has been studied in air containing water partial pressures between 200 vppm and ∼80000 vppm, at temperatures of 46 °C-96 °C. Specimens were exposed to air, with and without CO2, and argon gas. Metal consumption rates were measured and corrosion products characterised, using optical and scanning electron microscopy, energy dispersive x-ray microanalysis, x-ray diffraction and secondary ion mass spectrometry. Results show the importance of CO2 gas for suppressing breakaway corrosion in moist air.