Atmospheric Corrosion Behavior of Magnesium Alloys in Wanning Standard Test Site

The atmospheric corrosion behaviors of AZ31,AZ61 and AZ80 magnesium alloys were investigated by exposure test in Wanning standard test site. After two months exposure test, the corrosion morphologies and the components of the corrosion products were observed and analyzed by scanning electron microscopy(SEM) equipped with energy-dispersive X-ray spectrometer (EDS). The corrosion rates of magnesium alloys were calculated by mass-loss method. The results indicated that the atmospheric corrosion resistance of magnesium alloys in Wanning standard test site was improved with the content of aluminum added. The main corrosion behavior was pitting corrosion，and some claw holes appeared on part of the surface. Among the three magnesium alloys, the amount of claw holes on AZ31 was the most, and the area of each claw hole on AZ31 was the largest. There were more corrosion products on the back surfaces than on the front. The main constitute of the corrosion products was carbonate with few chloride.