Protection mechanism and identification of application areas of Mg-alloyed zinc coated steel

摘要

The effect of exposure conditions on the relative per-formance of traditional zinc coatings compared to coatings alloyed with magnesium and aluminium is documented and discussed. It is demonstrated on data obtained for painted materials at cut edges that the alloyed coatings provide improved protection ability in particular under conditions where zinc corrodes rap-idly, e.g. under high chloride load and permanently high wetness. A number of analytical techniques have been applied for detail analysis of cotrosion products formed in different stages of corrosion processes in order to understand the protection mechanism of the alloyed coatings.