When developing designs for metal tanks as well as the products used to protect them, corrosion engineers must address multiple types of corrosion.

Atmospheric corrosion is a type of decomposition studied in corrosion engineering as a significant sub-type of all corrosion that metals are exposed to.

Focused on elements within the atmosphere that cause the decay of different metals, corrosion engineering services recognize the following factors to be influential in the ways and the rates at which metal deteriorates.

1. Moisture

The primary factor that corrosion engineers must consider when assessing atmospheric corrosion is moisture in the environment.

Moisture is present in various forms including rain, dew, and condensation and based on the different behaviors of each of these types of moisture, corrosion can form in a variety of ways.

Dew and condensation may carry pollutants that dry on a surface, while rain can wash them off.

Rain, on the other hand, can enter different areas that dew and condensation cannot.

2. Temperature

Corrosion is directly affected by temperature.

Corrosion engineering addresses the fact that as the temperature rises, the decay rate increases with it.

This is especially critical when working with metal, which can experience temperature lag and remain heated longer, even when atmospheric temperatures have lowered.

Lag occurring as temperatures rise is also partly responsible for the formation of condensation, which can increase corrosion in its own ways.

3. Relative Atmospheric Humidity

Relative humidity is the percentage of water vapor present in the air at a certain temperature.

This vapor is comprised of particles that contain a specific electrolyte which produces a thin film when landing on surfaces.

Corrosion engineers have discovered that this electrolyte can promote corrosion in numerous ways, including by carrying high levels of other contaminants with it.

High humidity conditions, especially in salt air environments, can be especially corrosive due to the depositing of salt and other contaminants on metal surfaces and the contact wet and dry cycles that occur.

4. Aerosol Particle Concentration

Another factor that directly affects the corrosion of metals is the behavior of aerosol particles.

Aerosol formation and concentration are directly influenced by a variety of conditions including time, location, sources, wind velocity, atmospheric conditions, and altitude.

Corrosion engineering services see higher concentrations of aerosols in certain conditions, which can then lead to increased effects on metals via chemical reactions due to contaminants or due to ejection and wind velocity.

5. Atmospheric Pollutants

In all of the above cases, corrosion engineers also find that the presence of pollutants in the atmosphere plays a significant part in the deterioration of metals.

Pollutants like sulfur dioxide, nitrogen oxides, and other chemicals that are produced by combustion can be carried through the atmosphere.

Many of these pollutants will then become modified with exposure to moisture, UV light, and other conditions, turning them into more corrosive substances that can further affect different metals.

Atmospheric Corrosion A Prime Consideration In Corrosion Engineering

Corrosion engineering must look at metal corrosion from two different angles.

One type is the corrosion that is caused on the interior of a vessel due to direct contact with its contents, but the other type is that which is a result of the environment.

In addressing decay caused by atmospheric conditions, these are the five main factors that corrosion engineering services consider when developing tanks and protective coatings.