Corrosion: types, causes, and strategies to prevent it

Corroding pipes

Corrosion management and prevention are key factors in many industrial settings. If left untreated, corrosion can put infrastructure, security, and business performance at risk, with potentially devastating consequences. It also has a negative impact on revenue: an international study by NACE estimates the annual cost of corrosion to be $2.5 trillion.
In contrast, designers have more tools at their disposal than in the past. Learn more about the types and causes of corrosion, advances in materials development, and guidance on recommended practices that enable professionals to prevent and reduce metal deterioration.

The information in this post summarizes a recent Parker whitepaper on how to combat corrosion.

Download now

Definition of corrosion

Corrosion is the process by which infrastructure, products, and components can deteriorate due to a chemical or electrochemical reaction with the environment.

Main types of corrosion

Nowadays, six types of corrosion are commonly encountered in industrial applications:
– Galvanic corrosion occurs when two different electrochemical materials (e.g., steel and brass) come into contact in a corrosive environment, causing the less resistant material to corrode
– Spot corrosion occurs when small holes quickly penetrate deep into the inner part of the metal, but the rest of the metal surface remains intact. Generally occurs for self-passivating metals such as stainless steel or aluminum alloys
– Uniform corrosion occurs at a constant rate, leaving a uniform deposit on the surface of the exposed metal
– Crevice corrosion is found where stagnant liquids generate small spaces locally, such as pockets or corners
– Intergranular corrosion occurs on or near a granular structure of an alloy, giving rise to localized attacks
– Stress corrosion occurs where a material is subjected to continuous or variable stress in a corrosive environment, generating fractures.

What causes corrosion?

The causes of corrosion are complex and vary from industry to industry. Some common examples from specific industries are listed below:
– Corrosion in construction often occurs because metals are exposed to external agents and extreme temperatures
– Underground mining operations are characterized by an acidic environment in the presence of water (often with chlorides and sulfates), combined with high temperature and humidity
– Corrosion in forestry often occurs in remote locations, involves equipment parked on grassy surfaces or uneven terrain where large amounts of moisture are generated overnight, which can corrode on-board systems and mechanical components.
Environmental conditions also affect the speed and degree of corrosion spreading. In the presence of moisture, liquids are generated that cause a reaction whereby metals corrode much faster than they would in dry conditions.
In a corrosive environment, one or more of these factors are often present:
– Moisture
– Temperature extremes
– Surface liquids
– Atmospheric dust
– Salts
– Industrial lubricants.

Preventing and managing corrosion

Engineers can use a variety of techniques to reduce or prevent corrosion. These techniques, described in more detail in the white paper on how to counter corrosion, include:
– Choice of materials: choosing the most appropriate materials for the activity and the environment is crucial. Although all metals can corrode in an aggressive environment, the performance of alloys can vary dramatically; choosing the right balance of tensile strength, thermal, chemical, and corrosive resistance is critical
– Compatibility between materials: when designing, engineers must consider contact between potentially incompatible materials; for example, combinations such as copper and stainless steel, or bronze and steel, can give rise to galvanic corrosion. Choosing compatible metals and alloys, or using insulation to prevent the formation of an electrical path, can be helpful in overcoming this obstacle
– Protective coatings: some metals, such as steel, iron and aluminum, may have a corrosion-resistant coating applied as protection. The choice of the optimal metal and coating technique depends on a careful analysis of the strength, durability, friction, torque, and corrosion resistance of the asset
– Corrosion testing: controlled tests can simulate a variety of corrosive atmospheres, including salt water jets, salt spray, dryness and humidity. Such tests are generally performed for very precise specifications, such as recreating seasonal weather cycles to replicate real environments
– Corrosion management: effective corrosion management can enable companies to manage threats efficiently. Condition monitoring and incident logs help generate clearer information on corrosion practices; in addition, information sharing between departments highlights possible relationships between capital spent, post-processing practices, and resource life.

Counteracting corrosion: whitepaper

Download the whitepaper now

Download now

This article was written with input from Dr. Philipp WagenerThis article was written with input from Dr. Philipp Wagener

Related articles:

Dust is more harmful than you think

Corrosion management and prevention are key factors in many industrial settings. If left untreated, corrosion can put infrastructure, security, and business performance at risk, with potentially devastating consequences. It also has a negative impact on revenue: an international study by NACE estimates the annual cost of corrosion to be $2.5 trillion.
In contrast, designers have more tools at their disposal than in the past. Learn more about the types and causes of corrosion, advances in materials development, and guidance on recommended practices that enable professionals to prevent and reduce metal deterioration.

The information in this post summarizes a recent Parker whitepaper on how to combat corrosion.

Definition of corrosion

Corrosion is the process by which infrastructure, products, and components can deteriorate due to a chemical or electrochemical reaction with the environment.

Main types of corrosion

Nowadays, six types of corrosion are commonly encountered in industrial applications:
– Galvanic corrosion occurs when two different electrochemical materials (e.g., steel and brass) come into contact in a corrosive environment, causing the less resistant material to corrode
– Spot corrosion occurs when small holes rapidly penetrate deep into the inner part of the metal, but the rest of the metal surface remains intact. Generally occurs for self-passivating metals such as stainless steel or aluminum alloys
– Uniform corrosion occurs at a constant rate, leaving a uniform deposit on the surface of the exposed metal
– Crevice corrosion is found where stagnant liquids generate small spaces locally, such as pockets or corners
– Intergranular corrosion occurs on or near a granular structure of an alloy, giving rise to localized attacks
– Stress corrosion occurs where a material is subjected to continuous or variable stress in a corrosive environment, generating fractures.

What causes corrosion?

The causes of corrosion are complex and vary from industry to industry. Some common examples from specific industries are listed below:
– Corrosion in construction often occurs because metals are exposed to external agents and extreme temperatures
– Underground mining operations are characterized by an acidic environment in the presence of water (often with chlorides and sulfates), combined with high temperature and humidity
– Corrosion in forestry often occurs in remote locations, involves equipment parked on grassy surfaces or uneven terrain where large amounts of moisture are generated overnight, which can corrode on-board systems and mechanical components.
Environmental conditions also affect the speed and degree of corrosion spreading. In the presence of moisture, liquids are generated that cause a reaction whereby metals corrode much faster than they would in dry conditions.
In a corrosive environment, one or more of these factors are often present:
– Moisture
– Temperature extremes
– Surface liquids
– Atmospheric dust
– Salts
– Industrial lubricants.

Preventing and managing corrosion

Engineers can use a variety of techniques to reduce or prevent corrosion. These techniques, described in more detail in the white paper on how to counter corrosion, include:
– Choice of materials: choosing the most appropriate materials for the activity and the environment is crucial. Although all metals can corrode in an aggressive environment, the performance of alloys can vary dramatically; choosing the right balance of tensile strength, thermal, chemical, and corrosive resistance is critical
– Compatibility between materials: when designing, engineers must consider contact between potentially incompatible materials; for example, combinations such as copper and stainless steel, or bronze and steel, can give rise to galvanic corrosion. Choosing compatible metals and alloys, or using insulation to prevent the formation of an electrical path, can be helpful in overcoming this obstacle
– Protective coatings: some metals, such as steel, iron and aluminum, may have a corrosion-resistant coating applied as protection. The choice of the optimal metal and coating technique depends on a careful analysis of the strength, durability, friction, torque, and corrosion resistance of the asset
– Corrosion testing: controlled tests can simulate a variety of corrosive atmospheres, including salt water jets, salt spray, dryness and humidity. Such tests are generally performed for very precise specifications, such as recreating seasonal weather cycles to replicate real environments
– Corrosion management: effective corrosion management can enable companies to manage threats efficiently. Condition monitoring and incident logs help generate clearer information on corrosion practices; in addition, information sharing between departments highlights possible relationships between capital spent, post-processing practices, and resource life.

Counteracting corrosion: whitepaper

Download the whitepaper now

This article was written with contributions from Dr. Philipp Wagener

Related articles:

Dust is more harmful than you think

Parker Hannifin | Parker Hannifin