Laboratory tests have been performed in order to determine how the climatic parameters e.g. relative humidity and temperature, and the amount of NaCl influence the corrosion rate of magnesium alloys AZ91D and AM50. The effect of the surface state has also been investigated. The exposures were performed at 75%, 85% and 95% R.H. and at 25 and 35C. The amount of sodium chloride ranged from 14 to 240 µg cm-². The corrosion rate of both materials increased as a function of temperature, relative humidity and NaCl amount. A strong influence of the surface state e.g. as cast or polished was observed mainly due the discontinuity of as cast surfaces.
Key Words: magnesium alloys, atmospheric corrosion, climatic parameters