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Corrosion in the Military
The annual cost of corrosion for the US Military - a combined total for the Army, Navy, Air Force and Marines - was estimated to be $20.0 Billion (Final Report FHWA-RD-01-156, 2001). The Report also indicates that corrosion is the number one driver toward Total Ownership Cost. A combined cost of $400 Million was estimated for Navy and Coast Guard ships alone.

One of the recommendations of this Report is that the US Military needs to increase its awareness and recognition of corrosion as an important factor in the life of military systems. This fact must be appreciated by all personnel, and training should be provided to develop sufficient knowledge to deal with corrosion.

The US Military is frequently required to operate under extreme conditions, including ones that result in corrosion damage. When a component becomes corroded or damaged beyond a certain point, it must be replaced. Replacement of some critical components can involve a significant time interval - in some cases, over a year. One potential solution involves repairing or fabricating the component in the field. It may also be possible to mitigate the problem by training personnel to recognize corrosion early.

Corrosion was reported in a number of locations on the Navy's new Littoral Combat Ships (LCS). In the case of one of the ships, both galvanic corrosion and pitting corrosion were identified in the propulsion areas. Alloys are frequently incorporated in a design - for reasons such as strength or cost - with little consideration in regard to potential corrosion issues that may develop in service.

In many cases, there is a need to reduce the weight of DoD Platforms which requires the use of lighter alloys such as magnesium. (Magnesium is utilized during the fabrication of rotary and fixed wing gearboxes.) Even a cursory look at the Galvanic Series will show that magnesium is a very active alloy which corrodes when exposed to an aggressive environment. Various treatments have been used over the years to reduce the corrosion of magnesium alloys. These treatments may include conversion coatings or anodized coatings (Dow 17, HAE, or Tagnite).

As systems age, the impact of corrosion increases. Therefore, corrosion must be recognized as a central issue if the US Military would like to extend the operational life of critical systems.
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