{"id":22955,"date":"2026-11-02T10:00:39","date_gmt":"2026-11-02T13:00:39","guid":{"rendered":"https:\/\/www.grupoacocearense.com.br\/?p=22955"},"modified":"2026-09-04T11:01:41","modified_gmt":"2026-09-04T14:01:41","slug":"corrosao-aco","status":"publish","type":"post","link":"https:\/\/www.grupoacocearense.com.br\/en\/corrosao-aco\/","title":{"rendered":"Everything you need to know about steel corrosion and how to avoid structural problems."},"content":{"rendered":"

The lifespan of metal structures depends on a factor invisible to the naked eye, but devastating when ignored: <\/span>corrosion<\/b>. This topic is of utmost importance to everyone working in civil construction and steel structures, especially for companies seeking to ensure quality in their projects and avoid unnecessary expenses on maintenance and repairs.\u00a0<\/span><\/p>\n

Understanding the importance of this, in this article we address every detail about corrosion in steel structures, its causes, effects, forms of protection, and practical examples that we have experienced in the market.<\/span><\/p>\n

The goal is to demonstrate, in practice, why understanding and combating corrosion is fundamental for anyone who builds or works with metal solutions. This content is based on our experience as part of the A\u00e7o Cearense Group, a leader in the sector, to equip engineers, metalworkers, builders, and technical professionals with up-to-date knowledge and reliable recommendations.<\/span><\/p>\n

What is corrosion in metal structures?<\/b><\/h2>\n

Corrosion in metallic structures is a physical-chemical process of spontaneous deterioration resulting from the interaction between the metal and its surrounding environment.\u00a0<\/span><\/p>\n

From a thermodynamic perspective, steel tends to return to its lowest energy state \u2014 the iron oxide found in nature \u2014 through anodic and cathodic reactions that occur on its surface.\u00a0<\/span><\/p>\n

This electrochemical phenomenon converts metallic iron into hydrated and unstable compounds, generically known as rust, whose main characteristic is an increase in volume and a drastic loss of ductility and mechanical strength.\u00a0<\/span><\/p>\n

In engineering, this transformation compromises the cross-section of structural elements, reducing the load-bearing capacity and reliability of components that were originally designed to withstand critical tensile and compressive stresses.<\/span><\/p>\n

This process can manifest itself overtly in exposed structures, such as bridges and warehouses, or in an insidious and hidden way, such as carbonation corrosion or chloride attack in reinforced concrete structures.\u00a0<\/span><\/p>\n

In these cases, the phenomenon is particularly dangerous, as the expansion of corrosion products generates internal stresses that cause the concrete cover to detach, silently accelerating structural degradation.\u00a0<\/span><\/p>\n

In field audits conducted by the A\u00e7o Cearense Group, we found that negligence in specifying protective barriers and underestimation of environmental aggressiveness are the main catalysts for severe pathologies.\u00a0<\/span><\/p>\n

Understanding corrosion kinetics is therefore a safety imperative. By delving deeper into this topic, we equip the construction industry with the necessary expertise to adopt cathodic protection systems., <\/span>galvanization<\/span><\/a> or high-performance coatings, ensuring the longevity of the structures and, primarily, the preservation of life.<\/span><\/p>\n

Why is steel susceptible to corrosion?<\/b><\/h2>\n

Steel, a combination of iron and carbon, is widely used in construction due to its mechanical strength and versatility. However, it is not an inert material. When exposed to the atmosphere, it undergoes spontaneous chemical reactions that lead to the formation of oxides. The main agent responsible for this is oxygen, present in air and water.<\/span><\/p>\n

Prolonged contact with moisture, oxygen, and chemical pollutants accelerates the appearance of rust.<\/b><\/p>\n

From small parts to large structures, the risk is shared. Furthermore, agents present in industrial, marine, or urban environments concentrate aggressive compounds, such as chlorides and acids, which enhance metallic wear.<\/span><\/p>\n

Certain applications, such as structures in coastal regions, require extra layers of protection. This is because, in these locations, the salinity of the air drastically reduces the time it takes for corrosion points to appear.<\/span><\/p>\n

How does the corrosion process occur?<\/b><\/h2>\n

Corrosion begins with a series of chemical reactions between the metal, oxygen, and moisture. <\/b>When steel comes into contact with water and air, an electrochemical cell is formed.\u00a0<\/span><\/p>\n

Different areas of the metal act as poles (anode and cathode), and the transfer of electrons transforms the iron into ions, which react with oxygen to form iron oxides \u2013 what is known as rust.<\/span><\/p>\n

This process can be intensified by several factors, such as chemical contaminants, temperature variations, soil acidity, and even welding residue left over from manufacturing. Below, we detail common steps in this process:<\/span><\/p>\n