CORROSION OF ALUMINIUM ALLOYS IN MARINE ENVIRONMENT (II) --A SUMMARY OF 16 YEARS EXPOSURE TESTING IN SEAWATER FULL IMMERSION ZONE

Corrosion results of aluminium alloys exposed to full immersion zone at Qingdao sea area of China for 16 years were obtained. LF2Y2, LF6M(BL), 180YS Al Mg Mn alloys and LF21M Al Mn alloy had good corrosion resistance in seawater. Corrosion resistance of L4M pure aluminium and LD2CS Al Mg Si Cu alloy was poor. Corrosion resistance of LY12CZ Al Cu Mg Mn alloy and LC4CS Al Zn Mg Cu alloys were very poor. Al cladding of LY12CZ(BL) and LC4CS(BL) alloys played a sacrificial anode role in corrosion process, and their base alloys were protected. Effect of fouling on corrosion of aluminium alloys in seawater is obvious. Mg, Mn may improve the corrosion resistance of aluminium in seawater. Si obviously deteriorates corrosion resistance of aluminium. Cu seriously deteriorates corrosion resistance of aluminium. Aluminium alloys that have relatively negative corrosion potentials are corrosion resistant, while aluminium alloys that have relatively positive corrosion potentials are not corrosion resistant.