U.S.NAVY ALUMINUM CORROSION STRATEGY

摘要

Aluminum is selected in ship design primarily for performance; reduced weight provides the potential for increased speed and if included in the superstructure lowers the center of gravity and thus improves their maneuverability. A secondary benefit from weight reduction is lower fuel consumption when operationally allowable. The 5XXX and 6XXX series of aluminums have unique characteristics that justify their employment in the fleet; for example, 5456-H166 has the highest as-welded strength of any aluminum. Aluminums do corrode and thus their use needs to be managed and a challenging issue is the sensitization and subsequent stress corrosion cracking of 5XXX aluminum with high magnesium content. This specific corrosion issue has been problematic on CG 47 class cruisers and a raft of short term remedies and long term repairs have been developed. Littoral Combat Ships, Joint High Speed Vessels and Landing Craft Air Cushion, to name a few, also employ 5XXX series aluminum and their corrosion plan will be unique but can benefit from the lessons learned from the CG 47 class cruisers. This paper will discuss the development of a strategy to develop and manage an aluminum corrosion control plan for the fleet.