The localized corrosion of Al 6XXX alloys

This paper presents some recent findings on localized corrosion with a focu s on Al 6XXX alloys and on the current rimes resistance (IR) voltage that e xists between the separated anodic and cathodic reactions. Some newly devel oped concepts help quantify the relationship between the IR voltage and the polarization curve that exists on the crevice wall, thereby providing for a deeper understanding on how crevice corrosion occurs in many metals and a lloys. A signature of the IR voltage form of crevice corrosion in metal/ el ectrolyte systems is the existence of an active/passive transition in their polarization curves. An aluminum/electrolyte system has been found to unde rgo this form of crevice corrosion. Some new results on intergranular corro sion in Al 6XXX alloys are also presented.