The military often has to work in areas with harsh conditions where the levels of humidity, heat and salt can reduce different kinds of equipment into scattered, corroded parts. While such corrosion can be detected and treated, it is both a difficult and costly affair.
Adopting a preventive approach is more practical, and the U.S. Navy aims to employ precautionary measures to preserve its aircraft, ships, vehicles and machinery. A number of methods have proven to be useful in facilitating this process, including water absorption, dehumidification, water displacing products and vapor corrosion inhibitors (VCI).
Water absorption
Water absorption is often resorted to as a temporary measure. Desiccants can function effectively where materials or equipment are likely to corrode due to exposure to damp or humid environments.
Silica gel, which is often used in such instances, captures the water in the atmosphere to keep the equipment safe from contact with water, and therefore protected from corroding. The performance of the desiccants varies with the water levels on the walls of the package and inside the package, as well as the degree of humidity that exists inside the materials contained in the package.
Dehumidification
This corrosion prevention method uses a sealant that restricts airflow on the metal surface regardless of whether the equipment in question is a container, tank or vehicle. In most cases, keeping the equipment sealed is a major challenge. But for the dehumidification process to be effective, this has to be done properly.
Once complete sealing is done, the moisture within is extracted using a dehumidifier. The process and the cost of the materials required to carry it out, however, make dehumidification less preferable in the military setting.
Water-displacing products
Owing to their inexpensive nature and the permanent protection they offer, water-displacing products have for a long time been a common feature in preventing corrosion. Most of these substances are petroleum-based and come in form of oils or greases. Their cost varies with the additives included to boost the protection they provide.
The main drawback to these substances is that solvent-based cleaners must be used to remove them, which therefore makes them hazardous not just to the environment, but to the individuals applying them as well.
Cortec Corporation notes: "The cost of labor to apply and remove the products as well as the solvent-based cleaners needed make this option laborious as well as costly and unsafe."
VCI
Traditional methods of preventing corrosion are expensive and hazardous, but the use of vapor corrosion inhibitors (VCI) is one of the technologically-advanced options that is now applied by the military.
VCI provides adequate protection for every part of the machinery, including cavities and crevices that may be inaccessible where other preventive methods are applied. VCI compounds, which are available as anodic, cathodic and mixed inhibitors, work by reducing the density of the corrosion current, restricting cathode diffusion or controlling the chemical reaction between the anode and cathode.
Harsh environments and different variables make it hard to determine when corrosion will occur or reach a critical stage, but putting a protection system in place ensures that existing machinery is efficiently utilized.
In addition to using the numerous chemical substances, crews on Navy ships are usually trained in how to carry out corrosion control assessments so that overall maintenance costs are kept in control without compromising on equipment safety. This means that the need for costly repairs and the chances of getting a military operation jeopardized are eliminated.
