How to Protect Industrial Assets by Early Detection of Corrosion
Out of the many different challenges faced by industries around the world, corrosion is amongst the most acute ones. It can silently destroy different metal components and surfaces, which often leads to structural failures, expensive repairs, and safety hazards. Large scale damage can only be prevented by early detection of corrosion signs. This brief article discusses how corrosion can be detected in the initial stages so that preventive measures can be implemented before any serious damage takes place.
Understanding the Basic Concept
A natural process, corrosion refers to deterioration of metals because of exposure to environmental factors such as moisture, chemicals, oxygen, and industrial pollutants. Corrosion often causes oxidation of metals, leading to the formation of rust. Discussed below are some corrosion types that have maximum impact on industrial structures.
- Uniform Corrosion: This type of corrosion takes place when a metal remains exposed to environmental elements for a long time. It tends to spread evenly across the surface of the metal.
- Crevice Corrosion: This type of corrosion is found mostly in confined areas where chemicals and moisture can accumulate. Crevice corrosion is quite common in fasteners and joints.
- Pitting Corrosion: This type of corrosion leads to the creation of localized and small holes in the metal surface. Most importantly, these holes often remain undetected until they cause significant damage to the metal.
- Galvanic Corrosion: This type of corrosion takes place in a conductive environment, when two different metals are brought into contact.
- SCC or Stress Corrosion Cracking: This refers to the development of cracks in a metal surface under the impact of corrosion and stress.
A clear understanding of different corrosion types is essential in identifying the potential risk faced by industrial assets.
Corrosion Signs:
When corrosion signs are detected early, it becomes relatively easier to prevent expensive repairs resulting from extensive damage. Here are some key indicators that are considered to be the initial signs of corrosion.
- Staining and Discoloration of the Surface: When a metal starts corroding, there is a change in its colour and this is one of the earliest visible indicators of corrosion. Some common signs of oxidation include reddish-brown spots, rust stains, and surface streaks. Unique discolorations may also take place in different metals. For example, rust is developed in iron, a white residue resembling powder is formed in aluminium, and copper surfaces turn green.
- Blistering and Roughness: There is also a change in the metal surface’s smoothness as corrosion continues. This is when signs such as blistering, bubbling, or rough patches are observed. All these signs indicate weakening of the protective layer because of underlying corrosion.
- Peeling and Cracking: In order to prevent corrosion, industries often use sealants, paints, and other protective layers. Cracking, peeling, and flaking of these coatings indicate that corrosion has accelerated.
- Weakness or Deformation of Structures: When corrosion is not addressed quickly, it can severely impact the integrity of metal equipment and structures. Some common signs of diminishing structural strength include sagging, warping, and bending in railing, beams, and supports.
When these corrosion signs are identified promptly, their progression can be stopped or slowed-down by implementing protective measures such as regular maintenance and inspections, protective coatings, cathodic protection, proper selection of materials, and more.
If you have any other questions or doubts related to corrosion or protective industrial coatings, please get in touch with us at Coating Management Solutions.