Corrosion Behavior of Extruded EW75 Mg-alloy in Shenyang Industrial Atmosphere
Mg-alloys as the lightest metallic structural materials have many excellent properties,but their corrosion resistance is poor.Thus the corrosion behavior of Mg-alloy in different service conditions need to be acquired.Especially,the composition of pollutants and meteorological factors in different atmo-spheric environments may affect the corrosion behavior of Mg-alloys.In this paper,the corrosion behav-ior of the extruded EW75 Mg-alloy in Shenyang industrial atmosphere was investigated by atmospheric exposure at Shenyang atmospheric test station located at 123°26'east and 41°46'north.After exposure for different durations,the test alloys were characterized by means of SEM,EDS and Raman spectrosco-py in terms of their surface and cross sectional morphology and the chemical composition of corrosion products.The results show that the dusts containing soluble salts in the industrial atmosphere were de-posited on the surface of the extruded EW75 Mg-alloy and form round-shaped corrosion products,which show good protection for the corresponding magnesium matrix;the potential difference between the fine precipitation phases and α-Mg is low,which exhibits weak micro-galvanic effect,resulting in the formation of uniform corrosion.In addition,the corrosion rate of Mg-alloys in Shenyang atmosphere is greatly influ-enced by seasonal variations.Compared with the low temperature and low humidity winter,the corrosion rate of the extruded EW75 Mg-alloy is significantly higher in the high temperature and high humidity sum-mer.
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维普
