There are a lot of things that can be vulnerable to corrosion. For example, in a manufacturing setting, if you have machines, you might have to apply a high-performance coating like organic zinc. That coating can protect steel and iron, so if you were to apply it to machinery, going back to the example, it would protect them from corrosion.
The following are five things to know about corrosion and its effects.
1. What Is It?
Corrosion is when metal deteriorates because of chemical reactions that occur between it and its surrounding environment. The type of metal and the conditions of the environment will affect the type of deterioration and the rate.
All metals can corrode. Some corrode faster than others. Pure iron is an example of a quickly corroding metal. Stainless steel, on the other hand, is much slower to corrode because it’s a combination of iron and alloys.
There are a group of Noble Metals that are a lot less reactive than other types, so they rarely corrode. They’re the only metals found in their pure form in nature, so they tend to be valuable and include platinum, gold, and silver.
Another way to describe corrosion is a naturally occurring process of deterioration resulting from an electrochemical or chemical environmental reaction.
2. Causes
With the exception of some types of high-temperature corrosion, all types occur through the action of an electrochemical cell.
A metal will corrode if it’s reacting with a substance like hydrogen, oxygen, an electrical current, or even bacteria and dirt. If a metal is placed under too much stress, corrosion can also happen.
3. Types
There are a few different types of corrosion, with the most common being uniform. Uniform corrosion evenly affects large areas of a surface.
Pitting corrosion is aggressive and hard to predict and detect. This type of corrosion is localized, and it happens when a corrosion cell is formed, and then it makes a hole or cavity. A structure can fail because of pitting corrosion, even though it only leads to a relatively minimal amount of metal loss.
Crevice corrosion is most common where oxygen is limited. It’s a form of localized corrosion that often occurs because of differences in the ion concentrations between two areas of a metal. The imbalance that results from the crevice and the remainder of the metal contributes to high corrosion rates.
Stress corrosion cracking is when there are cracks that grow because of a corrosive environment. This is most common with alloys compared to pure metals.
Galvanic corrosion is when there are two metals that are different, and they have physical or perhaps electrical contact, and they’re immersed in an electrolyte like salt water.
Localized corrosion attacks one part of the metal. Pitting and crevice corrosion can fall into this category, and so can filiform corrosion, which occurs when water comes through coating underplating or painted surfaces.
4. Effects
The annual cost of metal corrosion worldwide is estimated to be more than $2 trillion. Some experts estimate that anywhere from 25% to 30% of this could be avoided with the right protection.
Construction projects that are poorly planned can lead to the corrosion of structures. Corrosion can also cause indirect costs, reputational damage, and safety concerns.
Consider something like a corroded building, bridge, or ship—these situations can and do lead to injuries and deaths, so corrosion becomes not only a financial issue but one of overall health and safety.
5. Prevention and Mitigation
Finally, there are a lot of ways that you can put corrosion prevention and mitigation strategies in place as a business.
First, during the design process, thinking about the materials being selected and used is important. This is one of the best ways to prevent failures later on. Some of the things that impact materials choices include environmental corrosion resistance, mechanical properties, compatibility with other components, reliability, and appearance.
The system design is also important within the context of materials selection.
Another way to prevent corrosion is with protective coatings. These are thin layers of materials that are solid, and they’re applied to a substrate. Once they’re applied, these coatings act like a barrier for inhibiting or preventing corrosion, water exposure, and wear.
The surface is prepared, and then the coatings are applied in a process that usually includes a primer, full coating, and sealant.
Companies that are best suited to reducing the negative effects of corrosion usually follow practices that include corrosion management plans.
