According to international studies – including those by the World Corrosion Organization (WCO) and NACE International – corrosion causes annual costs of more than 2.5 trillion US dollars worldwide. This corresponds to approximately 3 to 4% of global gross domestic product. For Germany, annual losses due to corrosion damage are therefore estimated at an average of 110–140 billion euros. These figures highlight the enormous economic significance of corrosion protection and the need for innovative solutions in this field.
Effective corrosion protection strategies are a key economic factor and are essential for the transport and storage of bare metal parts.
"We have come to know and appreciate Excor as a very competent partner. Based on a plant-wide process inspection and its analysis, weak points were identified, the right measures were defined and corrosion costs were reduced by >95%."
Peter Müller - Corrosion Protection Officer
Robert Bosch AG Hallein
What is corrosion?
Corrosion (from Latin corrodere = ‘to decompose’) refers to the reaction of a material with its environment, causing it to be gradually damaged. What consumers recognise as ‘rust’ on metallic surfaces is just one form of it.
Typical causes of corrosion
Oxygen, moisture, aggressive gases, or residues on the surface lead to chemical or electrochemical reactions that attack the metal and result in material degradation.
These include, for example, dust, grease, or salts, which damage the protective layer and can lead to structural damage over time.
When is it considered corrosion damage?
Corrosion damage occurs when corrosion impairs the functionality, safety, or service life of a component or system. Corrosion is always a warning sign but does not necessarily mean immediate functional failure. For example, railway tracks are often slightly rusted but still perform their function.
However, initial signs of corrosion such as discoloration, surface changes, or reduced load-bearing capacity should be taken seriously. The key is to take countermeasures at an early stage.
Examples of types of metal corrosion
General corrosion
When corrosion spreads evenly across large areas of a metal surface, this is referred to as general corrosion. It leads to gradual material loss, but can usually be detected and controlled at an early stage.
Pitting corrosion
Pitting corrosion begins at isolated points, which expand further over time. The localised destruction of the protective passive layer results in deep holes in the material. Pitting corrosion is often triggered by chlorides in saline environments.
Crevice corrosion
Crevice corrosion occurs particularly in narrow gaps such as overlapping edges or weld seams. It is caused by reactions based on concentration differences, particularly in oxygen content, between the medium inside the crevice and the surrounding environment.
Bimetallic corrosion
Bimetallic corrosion (also known as contact or galvanic corrosion) is caused by electrochemical reactions between different metals. In this process, the less noble metal acts as the anode and corrodes, whilst the more noble metal (cathode) remains protected.
Active and passive corrosion protection
Corrosion protection can be divided into active and passive measures.
Active corrosion protection works through electrochemical reactions – for example, by means of sacrificial anodes that dissolve instead of the base metal – or through vapour-phase corrosion protection. In this process, VCI and ICB agents (Volatile Corrosion Inhibitors / Intelligent Corrosion Blockers) are used, which release corrosion-inhibiting molecules and thus form an invisible protective film on the metal surface.
Passive corrosion protection, on the other hand, acts as a physical barrier between the metal and the environment. Coatings or layers such as paints, enamel, plastics, or special corrosion protection oils reliably prevent moisture, oxygen, or other environmental influences from reaching the metal. Desiccants can also reduce the relative humidity in sealed packaging and prevent corrosion damage.
Prerequisites for effective corrosion protection
Effective corrosion protection begins with the cleanliness of the surface. Only clean surfaces allow coatings, inhibitors, or packaging systems to achieve their full effectiveness. Use special industrial cleaners that reliably remove residues and are specifically tailored to the composition of your components. This creates the foundation for long-term protection.
Corrosion-protective packaging
During the transport and storage of metallic goods, packaging plays a crucial role in corrosion protection. A distinction is made between three different temporary corrosion protection methods: the VCI/ICB method, the desiccant method, and the coating method. These methods differ, among other things, in terms of effort. VCI or ICB packaging with emitting corrosion inhibitors often represents the cleanest and most economical solution.
However, not only environmental influences but also the types of metal are decisive in choosing an effective corrosion protection method. EXCOR offers specific corrosion protection solutions for various metals or metal alloys.
"With ICB, we know that we are offering our customers a first-class solution that guarantees optimum corrosion protection for their products. The user-friendliness of ICB and the superior performance compared to VCI have convinced us in the long term."
Martin Wildner, Head of Logistics - MHS GmbH | Warehouse Waldmünchen, Burglengenfeld
