Fastener Corrosion: Why It's Not All About Rusting

When you are planning on buying or using fasteners, one of the concerns you might have is corrosion. When your fasteners end up being corroded, they often become difficult to remove, and may even damage the item that you had been fastening in the first place. This means that before you even order them, it would be wise to put in place measures that will ensure that you never have to deal with these problems. Some of the common ones include using a fastener material that does not corrode, or having the fasteners plated. You can also have them painted using special materials that will reduce corrosion.
One of the things you need to keep in mind when doing all this is that corrosion is not only limited to rusting. Though rusting is the most common form of corrosion, there are many other types that can have similar effects, and which you need to keep in mind as well. Taking them for granted has the same effect as letting rust damage your fasteners. Some of the other types of corrosion include:

General corrosion

This is a form of corrosion that occurs uniformly over the surface of the fastener. It is usually caused by an electrochemical process, and eventually leads to rusting. One of the major advantages of this form of corrosion is the fact that it is predictable, and this means that you can prevent it using several means. It’s also easy to manage; you don’t have to spend much to keep it in control. Some of the strategies you can use include plating the fasteners or keeping them away from humidity.

Galvanic corrosion

This is a type of corrosion that occurs when two metals of very different electrochemical charge are put in contact with each other. With time, there are electrons transferred from one metal to the other as a result of the difference in charge. This leads to a chemical reaction similar to rusting. It eventually leads to weakening and damage of the fasteners. The best way to prevent this from happening is by using fasteners that are made out of a metal that is close to the item being fastened in terms of electrical charge. The best way to do this is to make sure that both are of the same charge, though this is not always feasible.

 

Caustic agent corrosion

In this form of corrosion, a gas or liquid dissolves in water to form a compound that has strong oxidizing properties, such as hydrogen sulfide. When these compounds come into contact with the fasteners, they react and cause damage. The degree of damage usually depends on the length of time the two are in contact, as well as the chemical properties of both the caustic agent and the fasteners. For instance, fasteners made out of aluminum or platinum may not react much with most caustic agents.
These are just a few of the types of corrosion; there are many others that you need to account for when selecting fasteners. The best way to do this is to involve someone who is knowledgeable in the field when doing the selection process.