Preventing corrosion in metals is a growing concern among the metals industry. This is because, despite having very good conductivity and electrical properties, metals are prone to corrosion when exposed to an adverse environment.
Corrosion can be prevented through proper handling, storage, and recycling of these materials. The article discussed below highlights the various ways of prevention of corrosion. A major area of prevention of corrosion is the packaging. Metal and non-metal packaging should be made from a sturdy and high wear-resistant material.
Materials such as paper-grade steel and PVC are often recommended for packaging as they have very high tear-resistance levels and excellent resistance to the formation of stress cracks during use. However, PVC plastic is also considered a good packaging material and has very good anti-corrosion properties.
The overall physical state of the packing material should also be taken into consideration. For example, the presence of a vapor barrier prevents the surface of the material from absorbing moisture and thus facilitating the development of rust.
There are some metal or nonmetal materials that do not require a vapor barrier for effective corrosion control. Examples of such material include aluminum or copper sheathed in a binder or foam. Another example includes coated paper or Polyethylene Terephthalate (PET) that does not require a vapor barrier.
There are two main approaches used in the area of corrosion control. The first of which is to alter the physical basis weight of the packaging material. The basis weight is basically a measure of the weight that material will sink into, taking into account the difference in its external shapes, such as a flat surface or a cylindrical shape.
This approach is often combined with a second approach known as a desiccant masterbatch. A desiccant masterbatch is essentially a process where a very low moisture content or a very high salt concentration is applied to a piece of metal.
The metal then sinks slowly into a container of very low moisture. As a result, the metal does not get excited, meaning that there is no corrosion occurring. A further approach that is used to prevent the corrosion of metallic objects is referred to as the static charge. Many experts suggest that you use MIL DTL 5541 to lengthen the lifespan (and new look) of your metal surfaces.
This is done by subjecting a piece of metal to a low or high static electric field. When exposed to this field, the metal’s electrons move from a positive charge to a negative charge. These moves enable a chemical reaction that dissolves the metal, hence the removal of dust particles.
The most commonly used substances that undergo a static charge are polymers and metal salts. Both the approaches, the thermal treatment, and the static charge, have their own advantages. For example, the thermal treatment ensures that the metal continues to be free of any salt deposits, which could hamper the surface quality of the object.
This is why many of the packaging solutions use masterbatches, as salt residue can easily be dissolved using the thermal procedure. However, for objects that will be exposed to very high temperatures, especially those that will be placed under intense pressure, the static charge is a more desirable method to apply.
Another important factor to remember for preventing corrosion is ensuring that the objects being packed are designed to resist higher temperatures. As an example, metallic objects that will be placed in machinery will usually require some form of packing insulation.
It could be a paper bag or even some foam. Such material should be carefully chosen to ensure that it meets specific specifications. Additionally, packaging should also include some way to control and/or protect the objects during transport.
All of these methods should be considered for preventing corrosion in metals.