The PPA 571 coating protect metal fencing from corrosion for 15 years

6 Effective Methods Could be Used to Prevent Metal Corrosion

Posted on: October 6th, 2017 by byersbushblog

Metal corrosion can be slowed down, managed, and even stopped! That is of course if you know the proper way to do it. Essentially, when you speak of corrosion, you refer to the chemical or electrochemical reaction that happens between the material and the environment resulting in a deterioration of the material including its properties.

Preventing corrosion can be done in a number of ways based on the condition of the corroded metal. So what should you know about corrosion protection?

What is corrosion protection?

what is corrosion protection

Ask anyone who knows something about construction and they will tell you that steel is an efficient material used for buildings. Unfortunately, steel and other types of metals can be negatively impacted by the environment to the point where it can degrade.

Coating steel is therefore used as a way to protect against corrosion. This is important considering majority of large constructions are designed for a lifecycle of 50 to 100 years on the average. The type of corrosion protection often depends on the condition of the material and the environment where it would be used.

The goal of corrosion protection is to create a barrier coating that is tough enough to protect the material against the harshest of weather and environmental conditions. This added layer meets the standards of the most demanding industries to ensure not only longevity, but also safety.

How Can Metals Be Protected from Corrosion?

how can metals be protected from corrosion

There are different techniques used in corrosion protection. Generally, there are six acceptable classifications. What are they?

Environmental Modification – since corrosion is the result of the chemical interactions of the metal and the gasses found in the surrounding environment, taking one of these out of the equation reduces the chances for metal deterioration. What does this mean?

For example, if you limit the possible contact of seawater or rain with metals, you can limit the possibility of corrosion. The same can be said by reducing the chloride, oxygen, or sulfur in the surrounding environment.

 

Metal Selection and Surface Conditions – metal will always be prone to corrosion in any type of environment. Therefore, understanding environmental conditions combined with monitoring can reduce the chance of corrosion. A good way to start is to use metal corrosion resistance data and environmental condition data when choosing the type of metal you will use for construction.

When you monitor the surface conditions, you can immediately act once any portion becomes vulnerable through cracks or crevices. Keep in mind that even the strongest of metals will eventually succumb to wear and tear so you need to be vigilant if you want to keep corrosion at bay.

 

Cathodic Protection – when you put together two types of metals in a corrosive electrolyte, galvanic corrosion will occur. This type of corrosion often occurs with metals in seawater. It can also happen when two dissimilar metals are placed closed to each other in moist soils. This is the type of corrosion that we see on ship hulls and offshore rigs among others.

This type of protection counteracts corrosion through the conversion of the anodic sites on the surface of the metal to cathodic ones. The supply of free electrons polarizes the local cathodes. Introduction of galvanic anodes (sacrificial system) allows it to attract the metallic ions resulting in the corrosion of the anode instead of the metal. This means the anode has to be replaced regularly for continued corrosion protection.

Another way that cathodic protection is done is via impressed current protection. An alternative direct electrical current supply source will be needed. The positive terminal is connected to the auxiliary anode while the negative terminal goes to the metal. In this system the anode is never sacrificed.

 

Corrosion Inhibitors – these are chemicals designed to react with the surface of the metal or the environmental gasses to interrupt the formation of corrosion. The inhibitors form a protective film coating and applied either as a solution of through dispersion techniques.

Corrosion is slowed down based on the changes in the anodic or cathodic polarization behavior, decreased ion diffusion on the surface, or increased electrical resistance. Major industries prefer this type of corrosion protection because it can be applied to guard against unexpected corrosion.

Coatings – these are used to prevent the degradative effects on the metal. Coatings normally fall into different types of categories based on the polymer employed. You will normally find vinyl, water-soluble, powder, epoxy, and two-part urethane coatings among others. Paints fall under this classification of corrosion protection.

Plating – application of this corrosion protection creates decorative and beautiful finishes. Normally you will have a choice of mechanical plating, electroplating, electroless, and hot dipping. The difference among these lies on how the protection is applied as well as the type of material used for corrosion protection.

What Are the Main Causes of Corrosion?

what are the main causes corrosion

Before we look into the main causes of corrosion, let us try to understand the different forms of corrosion. What are these?

  • General – appearance of uniform corrosion that results in thinning of the steel;
  • Localized – this is the result of difference in physical or chemical conditions between connecting sites;
  • Bacterial – the formation of bacteria on the surface translates to formation of corrosion; and
  • Galvanic/Dissimilar Metal – corrosion happens when dissimilar metals come into contact with each other causing the setting up of corrosion cells.

 

Corrosion would normally be caused by a number of factors like the pH of the water for example. When exceeding safe levels, the pH can erode the protective coating of the metal resulting in corrosion. Oxygen is another contributor to corrosion. When continuously exposed to oxygen, the metal will eventually turn to rust.

 

What other factors cause corrosion? The chemical makeup or minerals in your water supply can reach harmful levels that it feeds the formation of corrosion. Believe it or not, the temperature of the water also can cause corrosion. The hotter the water, the more higher the chances of metals becoming corroded.

 

Aside from the changes in temperature, the changes in velocity and direction can also result in corrosion. What are the dangers of these? Since most of these involve water or your water supply, you can experience numerous health problems when the corrosion mixes with your potable water.

 

This is why you need to make sure that you get the right corrosion protection. Let Byers Bush Powder Coating help you today.

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