Steel corrosion

Corrosion is the degradation of materials due to a chemical or electrochemical reaction. Corrosion occurs when a metal is subjected to an aggressive environment. Most of the time, this is a combination of humidity and oxygen, but increased exposure to UV rays or certain forms of wear and tear can also pose a threat. The material alters, leaving its metallic state and transforming into salts (oxides, sulfides, carbonates), thus reverting to its natural state. Iron is highly reactive in this electrochemical process, and there are numerous ionic exchanges at its surface. In addition, aggravating factors can increase the corrosive power of an atmosphere. The first and most damaging consequence is the loss of mechanical properties.

Controlling corrosion is a challenge for all companies. Corrosion has financial, environmental and health and safety impacts. The cost of corrosion makes it a global issue, and there is even a World Corrosion Day. The direct cost of corrosion is equal to the indirect cost. Among the indirect costs, the loss of time, and therefore productivity, due to breakdowns, delays, failures and disputes is the most significant. Some failures can result in injury or death (e.g., bridge or machine breakage, water contamination, etc.). Defense, water networks, transport and construction are the four sectors in which corrosion is the most costly. Every year, corrosion is combated through maintenance and curative action. So it's essential to prevent it from happening in the first place. There are various means of protection available, but depending on the application and the ambient environment, the right one needs to be chosen. To do this, we need to understand the cause of corrosion in a given environment.