Potentiometric and Potentiostatic Determination of the Corrosion Rate of Welded 2519 Aluminum Alloy

A new aluminum alloy, designated 2519, was developed for superior stress corrosion resistance, but the galvanic corrosion characteristics of 2519 weldments are not well understood. This study demonstrates that the weld metal is cathodic to the heat affected zone (HAZ) and to the parent metal. The potential differences are smallest for the parent metal/HAZ couple and highest for the HAZ/weld metal couple. The results of the study agree with the corrosion relationship predicted by the potentiostatic results. The study concludes that corrosion protection of the welded structure is necessary for efficient application of 2519 aluminum weldments.